Tor Changelog

What's new in Tor 0.4.8.11

Apr 11, 2024

Minor feature (authority):
Reject 0.4.7.x series at the authority level. Closes ticket 40896.
Minor feature (dirauth, tor26):
New IP address and keys.
Minor feature (directory authority):
Allow BandwidthFiles "node_id" KeyValue without the dollar sign at the start of the hexdigit, in order to easier database queries combining Tor documents in which the relays fingerprint does not include it. Fixes bug 40891; bugfix on 0.4.7 (all supported versions of Tor).
Minor features (fallbackdir):
Regenerate fallback directories generated on April 10, 2024.
Minor features (geoip data):
Update the geoip files to match the IPFire Location Database, as retrieved on 2024/04/10.
Minor bugfixes (directory authorities):
Add a warning when publishing a vote or signatures to another directory authority fails. Fixes bug 40910; bugfix on 0.2.0.3-alpha.

New in Tor 0.4.8.10 (Dec 11, 2023)

New in Tor 0.4.8.9 (Nov 10, 2023)

New in Tor 0.4.8.7 (Oct 5, 2023)

New in Tor 0.4.8.6 (Sep 18, 2023)

New in Tor 0.4.8.5 (Aug 31, 2023)

New in Tor 0.4.8.4 (Aug 29, 2023)

New in Tor 0.4.8.3 RC (Aug 6, 2023)

New in Tor 0.4.7.14 (Jul 27, 2023)

New in Tor 0.4.8.2 Alpha (Jul 27, 2023)

Major bugfixes (vanguards):
Rotate to a new L2 vanguard whenever an existing one loses the Stable or Fast flag. Previously, we would leave these relays in the L2 vanguard list but never use them, and if all of our vanguards end up like this we wouldn't have any middle nodes left to choose from so we would fail to make onion-related circuits. Fixes bug 40805; bugfix on 0.4.7.1-alpha.
Minor feature (hs):
Fix compiler warnings in equix and hashx when building with clang. Closes ticket 40800.
Minor features (fallbackdir):
Regenerate fallback directories generated on July 12, 2023.
Minor features (geoip data):
Update the geoip files to match the IPFire Location Database, as retrieved on 2023/07/12.
Minor bugfix (congestion control):
Reduce the accepted range of a circuit's negotiated 'cc_sendme_inc' to be +/- 1 from bugfix on 0.4.7.4-alpha.
Remove unused congestion control algorithms and BDP calculation code, now that we have settled on and fully tuned Vegas. Fixes bug 40566; bugfix on 0.4.7.4-alpha.
Update default congestion control parameters to match consensus. Fixes bug 40709; bugfix on 0.4.7.4-alpha.
Minor bugfixes (compilation):
Fix "initializer is not a constant" compilation error that manifests itself on gcc versions < 8.1 and MSVC. Fixes bug 40773; bugfix on 0.4.8.1-alpha
Minor bugfixes (conflux):
Count leg launch attempts prior to attempting to launch them. This avoids inifinite launch attempts due to internal circuit building failures. Additionally, double-check that we have enough exits in our consensus overall, before attempting to launch conflux sets. Fixes bug 40811; bugfix on 0.4.8.1-alpha.
Fix a case where we were resuming reading on edge connections that were already marked for close. Fixes bug 40801; bugfix on 0.4.8.1-alpha.
Fix stream attachment order when creating conflux circuits, so that stream attachment happens after finishing the full link handshake, rather than upon set finalization. Fixes bug 40801; bugfix on 0.4.8.1-alpha.
Handle legs being closed or destroyed before computing an RTT (resulting in warns about too many legs). Fixes bug 40810; bugfix on 0.4.8.1-alpha.
Remove a "BUG" warning from conflux_pick_first_leg that can be triggered by broken or malicious clients. Fixes bug 40801; bugfix on 0.4.8.1-alpha.
Minor bugfixes (KIST):
Prevent KISTSchedRunInterval from having values of 0 or 1, neither of which work properly. Additionally, make a separate KISTSchedRunIntervalClient parameter, so that the client and relay KIST values can be set separately. Set the default of both to 2ms. Fixes bug 40808; bugfix on 0.3.2.1-alpha.

New in Tor 0.4.8.1 Alpha (Jul 12, 2023)

This is the first alpha of the 0.4.8.x series. Two major features in this version which are Conflux and onion service Proof-of-Work (PoW). There are also many small features in particular, worth noting, the MetricsPort is now exporting more relay and onion service metrics. Finally, there are also numerous minor bugfixes included in this version.
Major features (onion service, proof-of-work):
Implement proposal 327 (Proof-Of-Work). This is aimed at thwarting introduction flooding DoS attacks by introducing a dynamic Proof-Of-Work protocol that occurs over introduction circuits. This introduces several torrc options prefixed with "HiddenServicePoW" in order to control this feature. By default, this is disabled. Closes ticket 40634.
Major features (conflux):
Implement Proposal 329 (conflux traffic splitting). Conflux splits traffic across two circuits to Exits that support the protocol. These circuits are pre-built only, which means that if the pre-built conflux pool runs out, regular circuits will then be used. When using conflux circuit pairs, clients choose the lower-latency circuit to send data to the Exit. When the Exit sends data to the client, it maximizes throughput, by fully utilizing both circuits in a multiplexed fashion. Alternatively, clients can request that the Exit optimize for latency when transmitting to them, by setting the torrc option 'ConfluxClientUX latency'. Onion services are not currently supported, but will be in arti. Many other future optimizations will also be possible using this protocol. Closes ticket 40593.
Major features (dirauth):
Directory authorities and relays now interact properly with directory authorities if they change addresses. In the past, they would continue to upload votes, signatures, descriptors, etc to the hard-coded address in the configuration. Now, if the directory authority is listed in the consensus at a different address, they will direct queries to this new address. Implements ticket 40705.
Minor feature (CI):
Update CI to use Debian Bullseye for runners.
Minor feature (client, IPv6):
Make client able to pick IPv6 relays by default now meaning ClientUseIPv6 option now defaults to 1. Closes ticket 40785.
Minor feature (compilation):
Fix returning something other than "Unknown N/A" as libc version if we build tor on an O.S. like DragonFlyBSD, FreeBSD, OpenBSD or NetBSD.
Minor feature (cpuworker):
Always use the number of threads for our CPU worker pool to the number of core available but cap it to a minimum of 2 in case of a single core. Fixes bug 40713; bugfix on 0.3.5.1-alpha.
Minor feature (lzma):
Fix compiler warnings for liblzma >= 5.3.1. Closes ticket 40741.
Minor feature (MetricsPort, relay):
Expose time until online keys expires on the MetricsPort. Closes ticket 40546.
Minor feature (MetricsPort, relay, onion service):
Add metrics for the relay side onion service interactions counting seen cells. Closes ticket 40797. Patch by "friendly73".
Minor features (directory authorities):
Directory authorities now include their AuthDirMaxServersPerAddr config option in the consensus parameter section of their vote. Now external tools can better predict how they will behave. Implements ticket 40753.
Minor features (directory authority):
Add a new consensus method in which the "published" times on router entries in a microdesc consensus are all set to a meaningless fixed date. Doing this will make the download size for compressed microdesc consensus diffs much smaller. Part of ticket 40130; implements proposal 275.
Minor features (network documents):
Clients and relays no longer track the "published on" time declared for relays in any consensus documents. When reporting this time on the control port, they instead report a fixed date in the future. Part of ticket 40130.
Minor features (fallbackdir):
Regenerate fallback directories generated on June 01, 2023.
Minor features (geoip data):
Update the geoip files to match the IPFire Location Database, as retrieved on 2023/06/01.
Minor features (hs, metrics):
Add tor_hs_rend_circ_build_time and tor_hs_intro_circ_build_time histograms to measure hidden service rend/intro circuit build time durations. Part of ticket 40757.
Minor features (metrics):
Add a `reason` label to the HS error metrics. Closes ticket 40758.
Add service side metrics for REND and introduction request failures. Closes ticket 40755.
Add support for histograms. Part of ticket 40757.
oMinor features (pluggable transports):
Automatically restart managed Pluggable Transport processes when their process terminate. Resolves ticket 33669.
Minor features (portability, compilation):
Use OpenSSL 1.1 APIs for LibreSSL, fixing LibreSSL 3.5 compatibility. Fixes issue 40630; patch by Alex Xu (Hello71).
Minor features (relay):
Do not warn about configuration options that may expose a non-anonymous onion service. Closes ticket 40691.
Minor features (relays):
Trigger OOS when bind fails with EADDRINUSE. This improves fairness when a large number of exit connections are requested, and properly signals exhaustion to the network. Fixes issue 40597; patch by Alex Xu (Hello71).
Minor features (tests):
Avoid needless key reinitialization with OpenSSL during unit tests, saving significant time. Patch from Alex Xu.
Minor bugfix (relay, logging):
The wrong max queue cell size was used in a protocol warning logging statement. Fixes bug 40745; bugfix on 0.4.7.1-alpha.
Minor bugfixes (logging):
Avoid ""double-quoting"" strings in several log messages. Fixes bug 22723; bugfix on 0.1.2.2-alpha.
Correct a log message when cleaning microdescriptors. Fixes bug 40619; bugfix on 0.2.5.4-alpha.
Minor bugfixes (metrics):
Decrement hs_intro_established_count on introduction circuit close. Fixes bug 40751; bugfix on 0.4.7.12.
Minor bugfixes (pluggable transports, windows):
Remove a warning `BUG()` that could occur when attempting to execute a non-existing pluggable transport on Windows. Fixes bug 40596; bugfix on 0.4.0.1-alpha.
Minor bugfixes (relay):
Remove a "BUG" warning for an acceptable race between a circuit close and considering that circuit active. Fixes bug 40647; bugfix on 0.3.5.1-alpha.
Remove a harmless "Bug" log message that can happen in relay_addr_learn_from_dirauth() on relays during startup. Finishes fixing bug 40231. Fixes bug 40523; bugfix on 0.4.5.4-rc.
Minor bugfixes (sandbox):
Allow membarrier for the sandbox. And allow rt_sigprocmask when compiled with LTTng. Fixes bug 40799; bugfix on 0.3.5.1-alpha.
Fix sandbox support on AArch64 systems. More "*at" variants of syscalls are now supported. Signed 32 bit syscall parameters are checked more precisely, which should lead to lower likelihood of breakages with future compiler and libc releases. Fixes bug 40599; bugfix on 0.4.4.3-alpha.
Minor bugfixes (state file):
Avoid a segfault if the state file doesn't contains TotalBuildTimes along CircuitBuildAbandonedCount being above 0. Fixes bug 40437; bugfix on 0.3.5.1-alpha.
Removed features:
Remove the RendPostPeriod option. This was primarily used in Version 2 Onion Services and after its deprecation isn't needed anymore. Closes ticket 40431. Patch by Neel Chauhan.

New in Tor 0.4.7.13 (Jan 19, 2023)

This version contains three major bugfixes, two for relays and one for client being a security fix, TROVE-2022-002. We have added, for Linux, the support for IP_BIND_ADDRESS_NO_PORT for relays using OutboundBindAddress. We strongly recommend to upgrade to this version considering the important congestion control fix detailed below.
Major bugfixes (congestion control):
Avoid incrementing the congestion window when the window is not fully in use. Thia prevents overshoot in cases where long periods of low activity would allow our congestion window to grow, and then get followed by a burst, which would cause queue overload. Also improve the increment checks for RFC3742. Fixes bug 40732; bugfix on 0.4.7.5-alpha.
Major bugfixes (relay):
When opening a channel because of a circuit request that did not include an Ed25519 identity, record the Ed25519 identity that we actually received, so that we can use the channel for other circuit requests that _do_ list an Ed25519 identity. (Previously we had code to record this identity, but a logic bug caused it to be disabled.) Fixes bug 40563; bugfix on 0.3.0.1-alpha. Patch from "cypherpunks".
Major bugfixes (TROVE-2022-002, client):
The SafeSocks option had its logic inverted for SOCKS4 and SOCKS4a. It would let the unsafe SOCKS4 pass but not the safe SOCKS4a one. This is TROVE-2022-002 which was reported on Hackerone by "cojabo". Fixes bug 40730; bugfix on 0.3.5.1-alpha.
Minor feature (authority):
Reject 0.4.6.x series at the authority level. Closes ticket 40664.
Minor features (fallbackdir):
Regenerate fallback directories generated on January 12, 2023.
Minor features (geoip data):
Update the geoip files to match the IPFire Location Database, as retrieved on 2023/01/12.
Minor features (relays):
Set the Linux-specific IP_BIND_ADDRESS_NO_PORT option on outgoing sockets, allowing relays using OutboundBindAddress to make more outgoing connections than ephemeral ports, as long as they are to separate destinations. Related to issue 40597; patch by Alex Xu (Hello71).
Minor bugfixes (relay, metrics):
Fix typo in a congestion control label on the MetricsPort. Fixes bug 40727; bugfix on 0.4.7.12.
Minor bugfixes (sandbox, authority):
With the sandbox enabled, allow to write "my-consensus-{ns|microdesc}" and to rename them as well. Fixes bug 40729; bugfix on 0.3.5.1-alpha.
Code simplifications and refactoring:
Rely on actual error returned by the kernel when choosing what resource exhaustion to log. Fixes issue 40613; Fix on tor-0.4.6.1-alpha.

New in Tor 0.4.7.12 (Dec 7, 2022)

New in Tor 0.4.7.8 (Jun 19, 2022)

New in Tor 0.4.7.7 (Jun 17, 2022)

New in Tor 0.4.6.7 (Aug 17, 2021)

New in Tor 0.4.6.6 (Jun 30, 2021)

New in Tor 0.4.6.5 (Jun 14, 2021)

New in Tor 0.4.5.8 (May 10, 2021)

Minor features (compatibility, Linux seccomp sandbox, backport from 0.4.6.3-rc):
Add a workaround to enable the Linux sandbox to work correctly with Glibc 2.33. This version of Glibc has started using the fstatat() system call, which previously our sandbox did not allow. Closes ticket 40382; see the ticket for a discussion of trade-offs.
Minor features (compilation, backport from 0.4.6.3-rc):
Make the autoconf script build correctly with autoconf versions 2.70 and later. Closes part of ticket 40335.
Minor features (fallback directory list, backport from 0.4.6.2-alpha):
Regenerate the list of fallback directories to contain a new set of 200 relays. Closes ticket 40265.
Minor features (geoip data):
Update the geoip files to match the IPFire Location Database, as retrieved on 2021/05/07.
Minor features (onion services):
Add warning message when connecting to now deprecated v2 onion services. As announced, Tor 0.4.5.x is the last series that will support v2 onions. Closes ticket 40373.
Minor bugfixes (bridge, pluggable transport, backport from 0.4.6.2-alpha):
Fix a regression that made it impossible start Tor using a bridge line with a transport name and no fingerprint. Fixes bug 40360; bugfix on 0.4.5.4-rc.
Minor bugfixes (build, cross-compilation, backport from 0.4.6.3-rc):
Allow a custom "ar" for cross-compilation. Our previous build script had used the $AR environment variable in most places, but it missed one. Fixes bug 40369; bugfix on 0.4.5.1-alpha.
Minor bugfixes (channel, DoS, backport from 0.4.6.2-alpha):
Fix a non-fatal BUG() message due to a too-early free of a string, when listing a client connection from the DoS defenses subsystem. Fixes bug 40345; bugfix on 0.4.3.4-rc.
Minor bugfixes (compiler warnings, backport from 0.4.6.3-rc):
Fix an indentation problem that led to a warning from GCC 11.1.1. Fixes bug 40380; bugfix on 0.3.0.1-alpha.
Minor bugfixes (controller, backport from 0.4.6.1-alpha):
Fix a "BUG" warning that would appear when a controller chooses the first hop for a circuit, and that circuit completes. Fixes bug 40285; bugfix on 0.3.2.1-alpha.
Minor bugfixes (onion service, client, memory leak, backport from 0.4.6.3-rc):
Fix a bug where an expired cached descriptor could get overwritten with a new one without freeing it, leading to a memory leak. Fixes bug 40356; bugfix on 0.3.5.1-alpha.
Minor bugfixes (testing, BSD, backport from 0.4.6.2-alpha):
Fix pattern-matching errors when patterns expand to invalid paths on BSD systems. Fixes bug 40318; bugfix on 0.4.5.1-alpha. Patch by Daniel Pinto.

New in Tor 0.4.5.7 (Mar 17, 2021)

New in Tor 0.4.5.6 (Feb 16, 2021)

New in Tor 0.4.4.7 (Feb 4, 2021)

New in Tor 0.4.4.6 (Nov 14, 2020)

New in Tor 0.4.4.5 (Sep 15, 2020)

New in Tor 0.4.3.6 (Jul 10, 2020)

New in Tor 0.4.3.5 (Jun 17, 2020)

New in Tor 0.4.2.7 (Mar 20, 2020)

Major bugfixes (security, denial-of-service, backport from 0.4.3.3-alpha):
Fix a denial-of-service bug that could be used by anyone to consume a bunch of CPU on any Tor relay or authority, or by directories to consume a bunch of CPU on clients or hidden services. Because of the potential for CPU consumption to introduce observable timing patterns, we are treating this as a high-severity security issue. Fixes bug 33119; bugfix on 0.2.1.5-alpha. Found by OSS-Fuzz. We are also tracking this issue as TROVE-2020-002 and CVE-2020-10592.
Major bugfixes (circuit padding, memory leak, backport from 0.4.3.3-alpha):
Avoid a remotely triggered memory leak in the case that a circuit padding machine is somehow negotiated twice on the same circuit. Fixes bug 33619; bugfix on 0.4.0.1-alpha. Found by Tobias Pulls. This is also tracked as TROVE-2020-004 and CVE-2020-10593.
Major bugfixes (directory authority, backport from 0.4.3.3-alpha):
Directory authorities will now send a 503 (not enough bandwidth) code to clients when under bandwidth pressure. Known relays and other authorities will always be answered regardless of the bandwidth situation. Fixes bug 33029; bugfix on 0.1.2.5-alpha.
Minor features (continuous integration, backport from 0.4.3.2-alpha):
Stop allowing failures on the Travis CI stem tests job. It looks like all the stem hangs we were seeing before are now fixed. Closes ticket 33075.
Minor bugfixes (bridges, backport from 0.4.3.1-alpha):
Lowercase the configured value of BridgeDistribution before adding it to the descriptor. Fixes bug 32753; bugfix on 0.3.2.3-alpha.
Minor bugfixes (logging, backport from 0.4.3.2-alpha):
If we encounter a bug when flushing a buffer to a TLS connection, only log the bug once per invocation of the Tor process. Previously we would log with every occurrence, which could cause us to run out of disk space. Fixes bug 33093; bugfix on 0.3.2.2-alpha.
Minor bugfixes (onion services v3, backport from 0.4.3.3-alpha):
Fix an assertion failure that could result from a corrupted ADD_ONION control port command. Found by Saibato. Fixes bug 33137; bugfix on 0.3.3.1-alpha. This issue is also tracked as TROVE-2020-003.
Minor bugfixes (rust, build, backport from 0.4.3.2-alpha):
Fix a syntax warning given by newer versions of Rust that was creating problems for our continuous integration. Fixes bug 33212; bugfix on 0.3.5.1-alpha.
Testing (Travis CI, backport from 0.4.3.3-alpha):
Remove a redundant distcheck job. Closes ticket 33194.
Sort the Travis jobs in order of speed: putting the slowest jobs first takes full advantage of Travis job concurrency. Closes ticket 33194.
Stop allowing the Chutney IPv6 Travis job to fail. This job was previously configured to fast_finish (which requires allow_failure), to speed up the build. Closes ticket 33195.
When a Travis chutney job fails, use chutney's new "diagnostics.sh" tool to produce detailed diagnostic output. Closes ticket 32792.

New in Tor 0.4.2.6 (Jan 31, 2020)

New in Tor 0.4.2.5 (Dec 10, 2019)

Major features (directory authorities):
Directory authorities now reject relays running all currently deprecated release series. The currently supported release series are: 0.2.9, 0.3.5, 0.4.0, 0.4.1, and 0.4.2. Closes ticket 31549.
Major features (onion service v3, denial of service):
Add onion service introduction denial of service defenses. Intro points can now rate-limit client introduction requests, using parameters that can be sent by the service within the ESTABLISH_INTRO cell. If the cell extension for this is not used, the intro point will honor the consensus parameters. Closes ticket 30924.
Major bugfixes (circuit build, guard):
When considering upgrading circuits from "waiting for guard" to "open", always ignore circuits that are marked for close. Previously we could end up in the situation where a subsystem is notified of a circuit opening, but the circuit is still marked for close, leading to undesirable behavior. Fixes bug 30871; bugfix on 0.3.0.1-alpha.
Major bugfixes (crash, Linux, Android):
Tolerate systems (including some Android installations) where madvise and MADV_DONTDUMP are available at build-time, but not at run time. Previously, these systems would notice a failed syscall and abort. Fixes bug 31570; bugfix on 0.4.1.1-alpha.
Tolerate systems (including some Linux installations) where madvise and/or MADV_DONTFORK are available at build-time, but not at run time. Previously, these systems would notice a failed syscall and abort. Fixes bug 31696; bugfix on 0.4.1.1-alpha.
Major bugfixes (embedded Tor):
Avoid a possible crash when restarting Tor in embedded mode and enabling a different set of publish/subscribe messages. Fixes bug 31898; bugfix on 0.4.1.1-alpha.
Major bugfixes (relay):
Relays now respect their AccountingMax bandwidth again. When relays entered "soft" hibernation (which typically starts when we've hit 90% of our AccountingMax), we had stopped checking whether we should enter hard hibernation. Soft hibernation refuses new connections and new circuits, but the existing circuits can continue, meaning that relays could have exceeded their configured AccountingMax. Fixes bug 32108; bugfix on 0.4.0.1-alpha.
Major bugfixes (torrc parsing):
Stop ignoring torrc options after an %include directive, when the included directory ends with a file that does not contain any config options (but does contain comments or whitespace). Fixes bug 31408; bugfix on 0.3.1.1-alpha.
Major bugfixes (v3 onion services):
Onion services now always use the exact number of intro points configured with the HiddenServiceNumIntroductionPoints option (or fewer if nodes are excluded). Before, a service could sometimes pick more intro points than configured. Fixes bug 31548; bugfix on 0.3.2.1-alpha.
Minor feature (onion services, control port):
The ADD_ONION command's keyword "BEST" now defaults to ED25519-V3 (v3) onion services. Previously it defaulted to RSA1024 (v2). Closes ticket 29669.
Minor features (auto-formatting scripts):
When annotating C macros, never generate a line that our check- spaces script would reject. Closes ticket 31759.
When annotating C macros, try to remove cases of double-negation. Closes ticket 31779.
Minor features (best practices tracker):
Our best-practices tracker now integrates with our include-checker tool to keep track of how many layering violations we have not yet fixed. We hope to reduce this number over time to improve Tor's modularity. Closes ticket 31176.
Add a TOR_PRACTRACKER_OPTIONS variable for passing arguments to practracker from the environment. We may want this for continuous integration. Closes ticket 31309.
Give a warning rather than an error when a practracker exception is violated by a small amount, add a --list-overbroad option to practracker that lists exceptions that are stricter than they need to be, and provide an environment variable for disabling practracker. Closes ticket 30752.
Our best-practices tracker now looks at headers as well as C files. Closes ticket 31175.
Minor features (build system):
Make pkg-config use --prefix when cross-compiling, if PKG_CONFIG_PATH is not set. Closes ticket 32191.
Add --disable-manpage and --disable-html-manual options to configure script. This will enable shortening build times by not building documentation. Resolves issue 19381.
Minor features (compilation):
Log a more useful error message when we are compiling and one of the compile-time hardening options we have selected can be linked but not executed. Closes ticket 27530.
Minor features (configuration):
The configuration code has been extended to allow splitting configuration data across multiple objects. Previously, all configuration data needed to be kept in a single object, which tended to become bloated. Closes ticket 31240.
Minor features (continuous integration):
When building on Appveyor and Travis, pass the "-k" flag to make, so that we are informed of all compilation failures, not just the first one or two. Closes ticket 31372.
When running CI builds on Travis, put some random data in ~/.torrc, to make sure no tests are reading the Tor configuration file from its default location. Resolves issue 30102.
Minor features (debugging):
Log a nonfatal assertion failure if we encounter a configuration line whose command is "CLEAR" but which has a nonempty value. This should be impossible, according to the rules of our configuration line parsing. Closes ticket 31529.
Minor features (geoip):
Update geoip and geoip6 to the December 3 2019 Maxmind GeoLite2 Country database. Closes ticket 32685.
Minor features (git hooks):
Our pre-commit git hook now checks for a special file before running practracker, so that practracker only runs on branches that are based on master. Since the pre-push hook calls the pre- commit hook, practracker will also only run before pushes of branches based on master. Closes ticket 30979.
Minor features (git scripts):
Add a "--" command-line argument, to separate git-push-all.sh script arguments from arguments that are passed through to git push. Closes ticket 31314.
Add a -r argument to git-push-all.sh, so the script can push test branches to a personal remote. Closes ticket 31314.
Add a -t argument to git-merge-forward.sh and git-push-all.sh, which makes these scripts create, merge forward, and push test branches. Closes ticket 31314.
Add a -u argument to git-merge-forward.sh, so that the script can re-use existing test branches after a merge failure and fix. Closes ticket 31314.
Add a TOR_GIT_PUSH env var, which sets the default git push command and arguments for git-push-all.sh. Closes ticket 31314.
Add a TOR_PUSH_DELAY variable to git-push-all.sh, which makes the script push master and maint branches with a delay between each branch. These delays trigger the CI jobs in a set order, which should show the most likely failures first. Also make pushes atomic by default, and make the script pass any command-line arguments to git push. Closes ticket 29879.
Call the shellcheck script from the pre-commit hook. Closes ticket 30967.
Skip pushing test branches that are the same as a remote maint/release/master branch in git-push-all.sh by default. Add a -s argument, so git-push-all.sh can push all test branches. Closes ticket 31314.
Minor features (IPv6, logging):
Log IPv6 addresses as well as IPv4 addresses when describing routerinfos, routerstatuses, and nodes. Closes ticket 21003.
Minor features (maintenance scripts):
Add a Coccinelle script to detect bugs caused by incrementing or decrementing a variable inside a call to log_debug(). Since log_debug() is a macro whose arguments are conditionally evaluated, it is usually an error to do this. One such bug was 30628, in which SENDME cells were miscounted by a decrement operator inside a log_debug() call. Closes ticket 30743.
Minor features (onion service v3):
Do not allow single hop clients to fetch or post an HS descriptor from an HSDir. Closes ticket 24964.
Minor features (onion service):
Disallow single-hop clients at the introduction point. We've removed Tor2web support a while back and single-hop rendezvous attempts are blocked at the relays. This change should remove load off the network from spammy clients. Close ticket 24963.
Minor features (onion services v3):
Assist users who try to setup v2 client authorization in v3 onion services by pointing them to the right documentation. Closes ticket 28966.
Minor features (stem tests):
Change "make test-stem" so it only runs the stem tests that use tor. This change makes test-stem faster and more reliable. Closes ticket 31554.
Minor features (testing):
When running tests that attempt to look up hostnames, replace the libc name lookup functions with ones that do not actually touch the network. This way, the tests complete more quickly in the presence of a slow or missing DNS resolver. Closes ticket 31841.
Add a script to invoke "tor --dump-config" and "tor --verify-config" with various configuration options, and see whether tor's resulting configuration or error messages are what we expect. Use it for integration testing of our +Option and /Option flags. Closes ticket 31637.
Improve test coverage for our existing configuration parsing and management API. Closes ticket 30893.
Add integration tests to make sure that practracker gives the outputs we expect. Closes ticket 31477.
The practracker self-tests are now run as part of the Tor test suite. Closes ticket 31304.
Minor features (testing, continuous integration):
Disable all but one Travis CI macOS build, to mitigate slow scheduling of Travis macOS jobs. Closes ticket 32177.
Run the chutney IPv6 networks as part of Travis CI. Closes ticket 30860.
Simplify the Travis CI build matrix, and optimise for build time. Closes ticket 31859.
Use Windows Server 2019 instead of Windows Server 2016 in our Appveyor builds. Closes ticket 32086.
Minor features (token bucket):
Implement a generic token bucket that uses a single counter, for use in anti-DoS onion service work. Closes ticket 30687.
Minor bugfixes (Appveyor continuous integration):
Avoid spurious errors when Appveyor CI fails before the install step. Fixes bug 31884; bugfix on 0.3.4.2-alpha.
Minor bugfixes (best practices tracker):
Fix a few issues in the best-practices script, including tests, tab tolerance, error reporting, and directory-exclusion logic. Fixes bug 29746; bugfix on 0.4.1.1-alpha.
When running check-best-practices, only consider files in the src subdirectory. Previously we had recursively considered all subdirectories, which made us get confused by the temporary directories made by "make distcheck". Fixes bug 31578; bugfix on 0.4.1.1-alpha.
Minor bugfixes (build system):
Interpret "--disable-module-dirauth=no" correctly. Fixes bug 32124; bugfix on 0.3.4.1-alpha.
Interpret "--with-tcmalloc=no" correctly. Fixes bug 32124; bugfix on 0.2.0.20-rc.
Stop failing when jemalloc is requested, but tcmalloc is not found. Fixes bug 32124; bugfix on 0.3.5.1-alpha.
When pkg-config is not installed, or a library that depends on pkg-config is not found, tell the user what to do to fix the problem. Fixes bug 31922; bugfix on 0.3.1.1-alpha.
Do not include the deprecated on Linux or Windows systems. Fixes bug 31673; bugfix on 0.2.5.4-alpha.
Minor bugfixes (chutney, makefiles, documentation):
"make test-network-all" now shows the warnings from each test- network.sh run on the console, so developers see new warnings early. We've also improved the documentation for this feature, and renamed a Makefile variable so the code is self-documenting. Fixes bug 30455; bugfix on 0.3.0.4-rc.
Minor bugfixes (client, onion service v3):
Fix a BUG() assertion that occurs within a very small race window between when a client intro circuit opens and when its descriptor gets cleaned up from the cache. The circuit is now closed early, which will trigger a re-fetch of the descriptor and continue the connection. Fixes bug 28970; bugfix on 0.3.2.1-alpha.
Minor bugfixes (code quality):
Fix "make check-includes" so it runs correctly on out-of-tree builds. Fixes bug 31335; bugfix on 0.3.5.1-alpha.
Minor bugfixes (compilation):
Add more stub functions to fix compilation on Android with link- time optimization when --disable-module-dirauth is used. Previously, these compilation settings would make the compiler look for functions that didn't exist. Fixes bug 31552; bugfix on 0.4.1.1-alpha.
Suppress spurious float-conversion warnings from GCC when calling floating-point classifier functions on FreeBSD. Fixes part of bug 31687; bugfix on 0.3.1.5-alpha.
Minor bugfixes (configuration):
Invalid floating-point values in the configuration file are now treated as errors in the configuration. Previously, they were ignored and treated as zero. Fixes bug 31475; bugfix on 0.0.1.
Minor bugfixes (connections):
Avoid trying to read data from closed connections, which can cause needless loops in Libevent and infinite loops in Shadow. Fixes bug 30344; bugfix on 0.1.1.1-alpha.
Minor bugfixes (controller protocol):
Fix the MAPADDRESS controller command to accept one or more arguments. Previously, it required two or more arguments, and ignored the first. Fixes bug 31772; bugfix on 0.4.1.1-alpha.
Minor bugfixes (coverity):
Add an assertion when parsing a BEGIN cell so that coverity can be sure that we are not about to dereference a NULL address. Fixes bug 31026; bugfix on 0.2.4.7-alpha. This is CID 1447296.
In our siphash implementation, when building for coverity, use memcpy in place of a switch statement, so that coverity can tell we are not accessing out-of-bounds memory. Fixes bug 31025; bugfix on 0.2.8.1-alpha. This is tracked as CID 1447293 and 1447295.
Fix several coverity warnings from our unit tests. Fixes bug 31030; bugfix on 0.2.4.1-alpha, 0.3.2.1-alpha, and 0.4.0.1-alpha.
Minor bugfixes (crash):
When running Tor with an option like --verify-config or --dump-config that does not start the event loop, avoid crashing if we try to exit early because of an error. Fixes bug 32407; bugfix on 0.3.3.1-alpha.
Minor bugfixes (developer tooling):
Only log git script changes in the post-merge script when the merge was to the master branch. Fixes bug 31040; bugfix on 0.4.1.1-alpha.
Minor bugfixes (directory authorities):
Return a distinct status when formatting annotations fails. Fixes bug 30780; bugfix on 0.2.0.8-alpha.
Minor bugfixes (error handling):
Always lock the backtrace buffer before it is used. Fixes bug 31734; bugfix on 0.2.5.3-alpha.
On abort, try harder to flush the output buffers of log messages. On some platforms (macOS), log messages could be discarded when the process terminates. Fixes bug 31571; bugfix on 0.3.5.1-alpha.
Report the tor version whenever an assertion fails. Previously, we only reported the Tor version on some crashes, and some non-fatal assertions. Fixes bug 31571; bugfix on 0.3.5.1-alpha.
When tor aborts due to an error, close log file descriptors before aborting. Closing the logs makes some OSes flush log file buffers, rather than deleting buffered log lines. Fixes bug 31594; bugfix on 0.2.5.2-alpha.
Minor bugfixes (FreeBSD, PF-based proxy, IPv6):
When extracting an IPv6 address from a PF-based proxy, verify that we are actually configured to receive an IPv6 address, and log an internal error if not. Fixes part of bug 31687; bugfix on 0.2.3.4-alpha.
Minor bugfixes (git hooks):
Remove a duplicate call to practracker from the pre-push hook. The pre-push hook already calls the pre-commit hook, which calls practracker. Fixes bug 31462; bugfix on 0.4.1.1-alpha.
Minor bugfixes (git scripts):
Stop hard-coding the bash path in the git scripts. Some OSes don't have bash in /usr/bin, others have an ancient bash at this path. Fixes bug 30840; bugfix on 0.4.0.1-alpha.
Stop hard-coding the tor master branch name and worktree path in the git scripts. Fixes bug 30841; bugfix on 0.4.0.1-alpha.
Allow git-push-all.sh to be run from any directory. Previously, the script only worked if run from an upstream worktree directory. Closes ticket 31678.
Minor bugfixes (guards):
When tor is missing descriptors for some primary entry guards, make the log message less alarming. It's normal for descriptors to expire, as long as tor fetches new ones soon after. Fixes bug 31657; bugfix on 0.3.3.1-alpha.
Minor bugfixes (ipv6):
Check for private IPv6 addresses alongside their IPv4 equivalents when authorities check descriptors. Previously, we only checked for private IPv4 addresses. Fixes bug 31088; bugfix on 0.2.3.21-rc. Patch by Neel Chauhan.
When parsing microdescriptors, we should check the IPv6 exit policy alongside IPv4. Previously, we checked both exit policies for only router info structures, while microdescriptors were IPv4-only. Fixes bug 27284; bugfix on 0.2.3.1-alpha. Patch by Neel Chauhan.
Minor bugfixes (logging):
Add a missing check for HAVE_PTHREAD_H, because the backtrace code uses mutexes. Fixes bug 31614; bugfix on 0.2.5.2-alpha.
Disable backtrace signal handlers when shutting down tor. Fixes bug 31614; bugfix on 0.2.5.2-alpha.
Rate-limit our the logging message about the obsolete .exit notation. Previously, there was no limit on this warning, which could potentially be triggered many times by a hostile website. Fixes bug 31466; bugfix on 0.2.2.1-alpha.
When initialising log domain masks, only set known log domains. Fixes bug 31854; bugfix on 0.2.1.1-alpha.
Change log level of message "Hash of session info was not as expected" to LOG_PROTOCOL_WARN. Fixes bug 12399; bugfix on 0.1.1.10-alpha.
Fix a code issue that would have broken our parsing of log domains as soon as we had 33 of them. Fortunately, we still only have 29. Fixes bug 31451; bugfix on 0.4.1.4-rc.
Minor bugfixes (logging, protocol violations):
Do not log a nonfatal assertion failure when receiving a VERSIONS cell on a connection using the obsolete v1 link protocol. Log a protocol_warn instead. Fixes bug 31107; bugfix on 0.2.4.4-alpha.
Minor bugfixes (mainloop, periodic events, in-process API):
Reset the periodic events' "enabled" flag when Tor is shut down cleanly. Previously, this flag was left on, which caused periodic events not to be re-enabled when Tor was relaunched in-process with tor_api.h after a shutdown. Fixes bug 32058; bugfix on 0.3.3.1-alpha.
Minor bugfixes (memory management):
Stop leaking a small amount of memory in nt_service_install(), in unreachable code. Fixes bug 30799; bugfix on 0.2.0.7-alpha. Patch by Xiaoyin Liu.
Minor bugfixes (modules):
Explain what the optional Directory Authority module is, and what happens when it is disabled. Fixes bug 31825; bugfix on 0.3.4.1-alpha.
Minor bugfixes (multithreading):
Avoid some undefined behaviour when freeing mutexes. Fixes bug 31736; bugfix on 0.0.7.
Minor bugfixes (networking, IP addresses):
When parsing addresses via Tor's internal DNS lookup API, reject IPv4 addresses in square brackets, and accept IPv6 addresses in square brackets. This change completes the work started in 23082, making address parsing consistent between tor's internal DNS lookup and address parsing APIs. Fixes bug 30721; bugfix on 0.2.1.5-alpha.
When parsing addresses via Tor's internal address:port parsing and DNS lookup APIs, require IPv6 addresses with ports to have square brackets. But allow IPv6 addresses without ports, whether or not they have square brackets. Fixes bug 30721; bugfix on 0.2.1.5-alpha.
Minor bugfixes (onion service v3):
When purging the client descriptor cache, close any introduction point circuits associated with purged cache entries. This avoids picking those circuits later when connecting to the same introduction points. Fixes bug 30921; bugfix on 0.3.2.1-alpha.
Minor bugfixes (onion services):
In the hs_ident_circuit_t data structure, remove the unused field circuit_type and the respective argument in hs_ident_circuit_new(). This field was set by clients (for introduction) and services (for introduction and rendezvous) but was never used afterwards. Fixes bug 31490; bugfix on 0.3.2.1-alpha. Patch by Neel Chauhan.
Minor bugfixes (operator tools):
Make tor-print-ed-signing-cert(1) print certificate expiration date in RFC 1123 and UNIX timestamp formats, to make output machine readable. Fixes bug 31012; bugfix on 0.3.5.1-alpha.
Minor bugfixes (process management):
Remove overly strict assertions that triggered when a pluggable transport failed to launch. Fixes bug 31091; bugfix on 0.4.0.1-alpha.
Remove an assertion in the Unix process backend. This assertion would trigger when we failed to find the executable for a child process. Fixes bug 31810; bugfix on 0.4.0.1-alpha.
Minor bugfixes (relay):
Avoid crashing when starting with a corrupt keys directory where the old ntor key and the new ntor key are identical. Fixes bug 30916; bugfix on 0.2.4.8-alpha.
Minor bugfixes (rust):
Correctly exclude a redundant rust build job in Travis. Fixes bug 31463; bugfix on 0.3.5.4-alpha.
Raise the minimum rustc version to 1.31.0, as checked by configure and CI. Fixes bug 31442; bugfix on 0.3.5.4-alpha.
Minor bugfixes (sendme, code structure):
Rename the trunnel SENDME file definition from sendme.trunnel to sendme_cell.trunnel to avoid having twice sendme.{c|h} in the repository. Fixes bug 30769; bugfix on 0.4.1.1-alpha.
Minor bugfixes (statistics):
Stop removing the ed25519 signature if the extra info file is too big. If the signature data was removed, but the keyword was kept, this could result in an unparseable extra info file. Fixes bug 30958; bugfix on 0.2.7.2-alpha.
Minor bugfixes (subsystems):
Make the subsystem init order match the subsystem module dependencies. Call windows process security APIs as early as possible. Initialize logging before network and time, so that network and time can use logging. Fixes bug 31615; bugfix on 0.4.0.1-alpha.
Minor bugfixes (testing):
Avoid intermittent test failures due to a test that had relied on inconsistent timing sources. Fixes bug 31995; bugfix on 0.3.1.3-alpha.
When testing port rebinding, don't busy-wait for tor to log. Instead, actually sleep for a short time before polling again. Also improve the formatting of control commands and log messages. Fixes bug 31837; bugfix on 0.3.5.1-alpha.
Teach the util/socketpair_ersatz test to work correctly when we have no network stack configured. Fixes bug 30804; bugfix on 0.2.5.1-alpha.
Minor bugfixes (tests, SunOS):
Avoid a map_anon_nofork test failure due to a signed/unsigned integer comparison. Fixes bug 31897; bugfix on 0.4.1.1-alpha.
Minor bugfixes (tls, logging):
Log bugs about the TLS read buffer's length only once, rather than filling the logs with similar warnings. Fixes bug 31939; bugfix on 0.3.0.4-rc.
Minor bugfixes (v2 single onion services):
Always retry v2 single onion service intro and rend circuits with a 3-hop path. Previously, v2 single onion services used a 3-hop path when rendezvous circuits were retried after a remote or delayed failure, but a 1-hop path for immediate retries. Fixes bug 23818; bugfix on 0.2.9.3-alpha.
Minor bugfixes (v3 onion services):
When cleaning up intro circuits for a v3 onion service, don't remove circuits that have an established or pending circuit, even if they ran out of retries. This way, we don't remove a circuit on its last retry. Fixes bug 31652; bugfix on 0.3.2.1-alpha.
Minor bugfixes (v3 single onion services):
Always retry v3 single onion service intro and rend circuits with a 3-hop path. Previously, v3 single onion services used a 3-hop path when rend circuits were retried after a remote or delayed failure, but a 1-hop path for immediate retries. Fixes bug 23818; bugfix on 0.3.2.1-alpha.
Make v3 single onion services fall back to a 3-hop intro, when all intro points are unreachable via a 1-hop path. Previously, v3 single onion services failed when all intro nodes were unreachable via a 1-hop path. Fixes bug 23507; bugfix on 0.3.2.1-alpha.
Code simplification and refactoring:
Refactor connection_control_process_inbuf() to reduce the size of a practracker exception. Closes ticket 31840.
Refactor the microdescs_parse_from_string() function into smaller pieces, for better comprehensibility. Closes ticket 31675.
Use SEVERITY_MASK_IDX() to find the LOG_* mask indexes in the unit tests and fuzzers, rather than using hard-coded values. Closes ticket 31334.
Interface for function `decrypt_desc_layer` cleaned up. Closes ticket 31589.
Documentation:
Correct the description of "GuardLifetime". Fixes bug 31189; bugfix on 0.3.0.1-alpha.
Make clear in the man page, in both the bandwidth section and the AccountingMax section, that Tor counts in powers of two, not powers of ten: 1 GByte is 1024*1024*1024 bytes, not one billion bytes. Resolves ticket 32106.
Document the signal-safe logging behaviour in the tor man page. Also add some comments to the relevant functions. Closes ticket 31839.
Explain why we can't destroy the backtrace buffer mutex. Explain why we don't need to destroy the log mutex. Closes ticket 31736.
The Tor source code repository now includes a (somewhat dated) description of Tor's modular architecture, in doc/HACKING/design. This is based on the old "tor-guts.git" repository, which we are adopting and superseding. Closes ticket 31849.
Improve documentation in circuit padding subsystem. Patch by Tobias Pulls. Closes ticket 31113.
Include an example usage for IPv6 ORPort in our sample torrc. Closes ticket 31320; patch from Ali Raheem.
Use RFC 2397 data URL scheme to embed an image into tor-exit- notice.html so that operators no longer have to host it themselves. Closes ticket 31089.
Removed features:
No longer include recommended package digests in votes as detailed in proposal 301. The RecommendedPackages torrc option is deprecated and will no longer have any effect. "package" lines will still be considered when computing consensuses for consensus methods that include them. (This change has no effect on the list of recommended Tor versions, which is still in use.) Closes ticket 29738.
Remove torctl.in from contrib/dist directory. Resolves ticket 30550.
Testing:
Require C99 standards-conforming code in Travis CI, but allow GNU gcc extensions. Also activates clang's -Wtypedef-redefinition warnings. Build some jobs with -std=gnu99, and some jobs without. Closes ticket 32500.
Run shellcheck for all non-third-party shell scripts that are shipped with Tor. Closes ticket 29533.
When checking shell scripts, ignore any user-created directories. Closes ticket 30967.
Code simplification and refactoring (config handling):
Extract our variable manipulation code from confparse.c to a new lower-level typedvar.h module. Closes ticket 30864.
Lower another layer of object management from confparse.c to a more general tool. Now typed structure members are accessible via an abstract type. Implements ticket 30914.
Move our backend logic for working with configuration and state files into a lower-level library, since it no longer depends on any tor-specific functionality. Closes ticket 31626.
Numerous simplifications in configuration-handling logic: remove duplicated macro definitions, replace magical names with flags, and refactor "TestingTorNetwork" to use the same default-option logic as the rest of Tor. Closes ticket 30935.
Replace our ad-hoc set of flags for configuration variables and configuration variable types with fine-grained orthogonal flags corresponding to the actual behavior we want. Closes ticket 31625.
Code simplification and refactoring (misc):
Eliminate some uses of lower-level control reply abstractions, primarily in the onion_helper functions. Closes ticket 30889.
Rework bootstrap tracking to use the new publish-subscribe subsystem. Closes ticket 29976.
Rewrite format_node_description() and router_get_verbose_nickname() to use strlcpy() and strlcat(). The previous implementation used memcpy() and pointer arithmetic, which was error-prone. Closes ticket 31545. This is CID 1452819.
Split extrainfo_dump_to_string() into smaller functions. Closes ticket 30956.
Use the ptrdiff_t type consistently for expressing variable offsets and pointer differences. Previously we incorrectly (but harmlessly) used int and sometimes off_t for these cases. Closes ticket 31532.
Use the subsystems mechanism to manage the main event loop code. Closes ticket 30806.
Various simplifications and minor improvements to the circuit padding machines. Patch by Tobias Pulls. Closes tickets 31112 and 31098.
Documentation (hard-coded directories):
Improve the documentation for the DirAuthority and FallbackDir torrc options. Closes ticket 30955.
Documentation (tor.1 man page):
Fix typo in tor.1 man page: the option is "--help", not "-help". Fixes bug 31008; bugfix on 0.2.2.9-alpha.
Testing (continuous integration):
Use Ubuntu Bionic images for our Travis CI builds, so we can get a recent version of coccinelle. But leave chutney on Ubuntu Trusty, until we can fix some Bionic permissions issues (see ticket 32240). Related to ticket 31919.
Install the mingw OpenSSL package in Appveyor. This makes sure that the OpenSSL headers and libraries match in Tor's Appveyor builds. (This bug was triggered by an Appveyor image update.) Fixes bug 32449; bugfix on 0.3.5.6-rc.
In Travis, use Xcode 11.2 on macOS 10.14. Closes ticket 32241.

New in Tor 0.4.1.5 (Aug 21, 2019)

New in Tor 0.4.0.5 (May 9, 2019)

Major features (battery management, client, dormant mode):
When Tor is running as a client, and it is unused for a long time, it can now enter a "dormant" state. When Tor is dormant, it avoids network and CPU activity until it is reawoken either by a user request or by a controller command. For more information, see the configuration options starting with "Dormant". Implements tickets 2149 and 28335.
The client's memory of whether it is "dormant", and how long it has spent idle, persists across invocations. Implements ticket 28624.
There is a DormantOnFirstStartup option that integrators can use if they expect that in many cases, Tor will be installed but not used.
Major features (bootstrap reporting):
When reporting bootstrap progress, report the first connection uniformly, regardless of whether it's a connection for building application circuits. This allows finer-grained reporting of early progress than previously possible, with the improvements of ticket 27169. Closes tickets 27167 and 27103. Addresses ticket 27308.
When reporting bootstrap progress, treat connecting to a proxy or pluggable transport as separate from having successfully used that proxy or pluggable transport to connect to a relay. Closes tickets 27100 and 28884.
Major features (circuit padding):
Implement preliminary support for the circuit padding portion of Proposal 254. The implementation supports Adaptive Padding (aka WTF-PAD) state machines for use between experimental clients and relays. Support is also provided for APE-style state machines that use probability distributions instead of histograms to specify inter-packet delay. At the moment, Tor does not provide any padding state machines that are used in normal operation: for now, this feature exists solely for experimentation. Closes ticket 28142.
Major features (refactoring):
Tor now uses an explicit list of its own subsystems when initializing and shutting down. Previously, these systems were managed implicitly in various places throughout the codebase. (There may still be some subsystems using the old system.) Closes ticket 28330.
Major bugfixes (cell scheduler, KIST, security):
Make KIST consider the outbuf length when computing what it can put in the outbuf. Previously, KIST acted as though the outbuf were empty, which could lead to the outbuf becoming too full. It is possible that an attacker could exploit this bug to cause a Tor client or relay to run out of memory and crash. Fixes bug 29168; bugfix on 0.3.2.1-alpha. This issue is also being tracked as TROVE-2019-001 and CVE-2019-8955.
Major bugfixes (networking):
Gracefully handle empty username/password fields in SOCKS5 username/password auth messsage and allow SOCKS5 handshake to continue. Previously, we had rejected these handshakes, breaking certain applications. Fixes bug 29175; bugfix on 0.3.5.1-alpha.
Major bugfixes (NSS, relay):
When running with NSS, disable TLS 1.2 ciphersuites that use SHA384 for their PRF. Due to an NSS bug, the TLS key exporters for these ciphersuites don't work -- which caused relays to fail to handshake with one another when these ciphersuites were enabled. Fixes bug 29241; bugfix on 0.3.5.1-alpha.
Major bugfixes (windows, startup):
When reading a consensus file from disk, detect whether it was written in text mode, and re-read it in text mode if so. Always write consensus files in binary mode so that we can map them into memory later. Previously, we had written in text mode, which confused us when we tried to map the file on windows. Fixes bug 28614; bugfix on 0.4.0.1-alpha.
Minor features (address selection):
Treat the subnet 100.64.0.0/10 as public for some purposes; private for others. This subnet is the RFC 6598 (Carrier Grade NAT) IP range, and is deployed by many ISPs as an alternative to RFC 1918 that does not break existing internal networks. Tor now blocks SOCKS and control ports on these addresses and warns users if client ports or ExtORPorts are listening on a RFC 6598 address. Closes ticket 28525. Patch by Neel Chauhan.
Minor features (bandwidth authority):
Make bandwidth authorities ignore relays that are reported in the bandwidth file with the flag "vote=0". This change allows us to report unmeasured relays for diagnostic reasons without including their bandwidth in the bandwidth authorities' vote. Closes ticket 29806.
When a directory authority is using a bandwidth file to obtain the bandwidth values that will be included in the next vote, serve this bandwidth file at /tor/status-vote/next/bandwidth. Closes ticket 21377.
Minor features (bootstrap reporting):
When reporting bootstrap progress, stop distinguishing between situations where only internal paths are available and situations where external paths are available. Previously, Tor would often erroneously report that it had only internal paths. Closes ticket 27402.
Minor features (compilation):
Compile correctly when OpenSSL is built with engine support disabled, or with deprecated APIs disabled. Closes ticket 29026. Patches from "Mangix".
Minor features (continuous integration):
On Travis Rust builds, cleanup Rust registry and refrain from caching the "target/" directory to speed up builds. Resolves issue 29962.
Log Python version during each Travis CI job. Resolves issue 28551.
In Travis, tell timelimit to use stem's backtrace signals, and launch python directly from timelimit, so python receives the signals from timelimit, rather than make. Closes ticket 30117.
Minor features (controller):
Add a DROPOWNERSHIP command to undo the effects of TAKEOWNERSHIP. Implements ticket 28843.
Minor features (developer tooling):
Check that bugfix versions in changes files look like Tor versions from the versions spec. Warn when bugfixes claim to be on a future release. Closes ticket 27761.
Provide a git pre-commit hook that disallows commiting if we have any failures in our code and changelog formatting checks. It is now available in scripts/maint/pre-commit.git-hook. Implements feature 28976.
Provide a git hook script to prevent "fixup!" and "squash!" commits from ending up in the master branch, as scripts/main/pre- push.git-hook. Closes ticket 27993.
Minor features (diagnostic):
Add more diagnostic log messages in an attempt to solve the issue of NUL bytes appearing in a microdescriptor cache. Related to ticket 28223.
Minor features (directory authority):
When a directory authority is using a bandwidth file to obtain bandwidth values, include the digest of that file in the vote. Closes ticket 26698.
Directory authorities support a new consensus algorithm, under which the family lines in microdescriptors are encoded in a canonical form. This change makes family lines more compressible in transit, and on the client. Closes ticket 28266; implements proposal 298.
Minor features (directory authority, relay):
Authorities now vote on a "StaleDesc" flag to indicate that a relay's descriptor is so old that the relay should upload again soon. Relays treat this flag as a signal to upload a new descriptor. This flag will eventually let us remove the 'published' date from routerstatus entries, and make our consensus diffs much smaller. Closes ticket 26770; implements proposal 293.
Minor features (dormant mode):
Add a DormantCanceledByStartup option to tell Tor that it should treat a startup event as cancelling any previous dormant state. Integrators should use this option with caution: it should only be used if Tor is being started because of something that the user did, and not if Tor is being automatically started in the background. Closes ticket 29357.
Minor features (fallback directory mirrors):
Update the fallback whitelist based on operator opt-ins and opt- outs. Closes ticket 24805, patch by Phoul.
Minor features (FreeBSD):
On FreeBSD-based systems, warn relay operators if the "net.inet.ip.random_id" sysctl (IP ID randomization) is disabled. Closes ticket 28518.
Minor features (geoip):
Update geoip and geoip6 to the April 2 2019 Maxmind GeoLite2 Country database. Closes ticket 29992.
Minor features (HTTP standards compliance):
Stop sending the header "Content-type: application/octet-stream" along with transparently compressed documents: this confused browsers. Closes ticket 28100.
Minor features (IPv6):
We add an option ClientAutoIPv6ORPort, to make clients randomly prefer a node's IPv4 or IPv6 ORPort. The random preference is set every time a node is loaded from a new consensus or bridge config. We expect that this option will enable clients to bootstrap more quickly without having to determine whether they support IPv4, IPv6, or both. Closes ticket 27490. Patch by Neel Chauhan.
When using addrs_in_same_network_family(), avoid choosing circuit paths that pass through the same IPv6 subnet more than once. Previously, we only checked IPv4 subnets. Closes ticket 24393. Patch by Neel Chauhan.
Minor features (log messages):
Improve log message in v3 onion services that could print out negative revision counters. Closes ticket 27707. Patch by "ffmancera".
Minor features (memory usage):
Save memory by storing microdescriptor family lists with a more compact representation. Closes ticket 27359.
Tor clients now use mmap() to read consensus files from disk, so that they no longer need keep the full text of a consensus in memory when parsing it or applying a diff. Closes ticket 27244.
Minor features (NSS, diagnostic):
Try to log an error from NSS (if there is any) and a more useful description of our situation if we are using NSS and a call to SSL_ExportKeyingMaterial() fails. Diagnostic for ticket 29241.
Minor features (parsing):
Directory authorities now validate that router descriptors and ExtraInfo documents are in a valid subset of UTF-8, and reject them if they are not. Closes ticket 27367.
Minor features (performance):
Cache the results of summarize_protocol_flags(), so that we don't have to parse the same protocol-versions string over and over. This should save us a huge number of malloc calls on startup, and may reduce memory fragmentation with some allocators. Closes ticket 27225.
Remove a needless memset() call from get_token_arguments, thereby speeding up the tokenization of directory objects by about 20%. Closes ticket 28852.
Replace parse_short_policy() with a faster implementation, to improve microdescriptor parsing time. Closes ticket 28853.
Speed up directory parsing a little by avoiding use of the non- inlined strcmp_len() function. Closes ticket 28856.
Speed up microdescriptor parsing by about 30%, to help improve startup time. Closes ticket 28839.
Minor features (pluggable transports):
Add support for emitting STATUS updates to Tor's control port from a pluggable transport process. Closes ticket 28846.
Add support for logging to Tor's logging subsystem from a pluggable transport process. Closes ticket 28180.
Minor features (process management):
Add a new process API for handling child processes. This new API allows Tor to have bi-directional communication with child processes on both Unix and Windows. Closes ticket 28179.
Use the subsystem manager to initialize and shut down the process module. Closes ticket 28847.
Minor features (relay):
When listing relay families, list them in canonical form including the relay's own identity, and try to give a more useful set of warnings. Part of ticket 28266 and proposal 298.
Minor features (required protocols):
Before exiting because of a missing required protocol, Tor will now check the publication time of the consensus, and not exit unless the consensus is newer than the Tor program's own release date. Previously, Tor would not check the consensus publication time, and so might exit because of a missing protocol that might no longer be required in a current consensus. Implements proposal 297; closes ticket 27735.
Minor features (testing):
Treat all unexpected ERR and BUG messages as test failures. Closes ticket 28668.
Allow a HeartbeatPeriod of less than 30 minutes in testing Tor networks. Closes ticket 28840. Patch by Rob Jansen.
Use the approx_time() function when setting the "Expires" header in directory replies, to make them more testable. Needed for ticket 30001.
Minor bugfixes (security):
Fix a potential double free bug when reading huge bandwidth files. The issue is not exploitable in the current Tor network because the vulnerable code is only reached when directory authorities read bandwidth files, but bandwidth files come from a trusted source (usually the authorities themselves). Furthermore, the issue is only exploitable in rare (non-POSIX) 32-bit architectures, which are not used by any of the current authorities. Fixes bug 30040; bugfix on 0.3.5.1-alpha. Bug found and fixed by Tobias Stoeckmann.
Verify in more places that we are not about to create a buffer with more than INT_MAX bytes, to avoid possible OOB access in the event of bugs. Fixes bug 30041; bugfix on 0.2.0.16. Found and fixed by Tobias Stoeckmann.
Minor bugfix (continuous integration):
Reset coverage state on disk after Travis CI has finished. This should prevent future coverage merge errors from causing the test suite for the "process" subsystem to fail. The process subsystem was introduced in 0.4.0.1-alpha. Fixes bug 29036; bugfix on 0.2.9.15.
Terminate test-stem if it takes more than 9.5 minutes to run. (Travis terminates the job after 10 minutes of no output.) Diagnostic for 29437. Fixes bug 30011; bugfix on 0.3.5.4-alpha.
Minor bugfixes (build, compatibility, rust):
Update Cargo.lock file to match the version made by the latest version of Rust, so that "make distcheck" will pass again. Fixes bug 29244; bugfix on 0.3.3.4-alpha.
Minor bugfixes (C correctness):
Fix an unlikely memory leak in consensus_diff_apply(). Fixes bug 29824; bugfix on 0.3.1.1-alpha. This is Coverity warning CID 1444119.
Minor bugfixes (client, clock skew):
Bootstrap successfully even when Tor's clock is behind the clocks on the authorities. Fixes bug 28591; bugfix on 0.2.0.9-alpha.
Select guards even if the consensus has expired, as long as the consensus is still reasonably live. Fixes bug 24661; bugfix on 0.3.0.1-alpha.
Minor bugfixes (compilation):
Fix compilation warnings in test_circuitpadding.c. Fixes bug 29169; bugfix on 0.4.0.1-alpha.
Silence a compiler warning in test-memwipe.c on OpenBSD. Fixes bug 29145; bugfix on 0.2.9.3-alpha. Patch from Kris Katterjohn.
Compile correctly on OpenBSD; previously, we were missing some headers required in order to detect it properly. Fixes bug 28938; bugfix on 0.3.5.1-alpha. Patch from Kris Katterjohn.
Minor bugfixes (directory clients):
Mark outdated dirservers when Tor only has a reasonably live consensus. Fixes bug 28569; bugfix on 0.3.2.5-alpha.
Minor bugfixes (directory mirrors):
Even when a directory mirror's clock is behind the clocks on the authorities, we now allow the mirror to serve "future" consensuses. Fixes bug 28654; bugfix on 0.3.0.1-alpha.
Minor bugfixes (DNS):
Gracefully handle an empty or absent resolve.conf file by falling back to using "localhost" as a DNS server (and hoping it works). Previously, we would just stop running as an exit. Fixes bug 21900; bugfix on 0.2.1.10-alpha.
Minor bugfixes (documentation):
Describe the contents of the v3 onion service client authorization files correctly: They hold public keys, not private keys. Fixes bug 28979; bugfix on 0.3.5.1-alpha. Spotted by "Felixix".
Minor bugfixes (guards):
In count_acceptable_nodes(), the minimum number is now one bridge or guard node, and two non-guard nodes for a circuit. Previously, we had added up the sum of all nodes with a descriptor, but that could cause us to build failing circuits when we had either too many bridges or not enough guard nodes. Fixes bug 25885; bugfix on 0.3.6.1-alpha. Patch by Neel Chauhan.
Minor bugfixes (IPv6):
Fix tor_ersatz_socketpair on IPv6-only systems. Previously, the IPv6 socket was bound using an address family of AF_INET instead of AF_INET6. Fixes bug 28995; bugfix on 0.3.5.1-alpha. Patch from Kris Katterjohn.
Minor bugfixes (linux seccomp sandbox):
Fix startup crash when experimental sandbox support is enabled. Fixes bug 29150; bugfix on 0.4.0.1-alpha. Patch by Peter Gerber.
Minor bugfixes (logging):
Correct a misleading error message when IPv4Only or IPv6Only is used but the resolved address can not be interpreted as an address of the specified IP version. Fixes bug 13221; bugfix on 0.2.3.9-alpha. Patch from Kris Katterjohn.
Log the correct port number for listening sockets when "auto" is used to let Tor pick the port number. Previously, port 0 was logged instead of the actual port number. Fixes bug 29144; bugfix on 0.3.5.1-alpha. Patch from Kris Katterjohn.
Stop logging a BUG() warning when Tor is waiting for exit descriptors. Fixes bug 28656; bugfix on 0.3.5.1-alpha.
Avoid logging that we are relaxing a circuit timeout when that timeout is fixed. Fixes bug 28698; bugfix on 0.2.4.7-alpha.
Log more information at "warning" level when unable to read a private key; log more information at "info" level when unable to read a public key. We had warnings here before, but they were lost during our NSS work. Fixes bug 29042; bugfix on 0.3.5.1-alpha.
Rework rep_hist_log_link_protocol_counts() to iterate through all link protocol versions when logging incoming/outgoing connection counts. Tor no longer skips version 5, and we won't have to remember to update this function when new link protocol version is developed. Fixes bug 28920; bugfix on 0.2.6.10.
Minor bugfixes (memory management):
Refactor the shared random state's memory management so that it actually takes ownership of the shared random value pointers. Fixes bug 29706; bugfix on 0.2.9.1-alpha.
Stop leaking parts of the shared random state in the shared-random unit tests. Fixes bug 29599; bugfix on 0.2.9.1-alpha.
Minor bugfixes (misc):
The amount of total available physical memory is now determined using the sysctl identifier HW_PHYSMEM (rather than HW_USERMEM) when it is defined and a 64-bit variant is not available. Fixes bug 28981; bugfix on 0.2.5.4-alpha. Patch from Kris Katterjohn.
Minor bugfixes (networking):
Introduce additional checks into tor_addr_parse() to reject certain incorrect inputs that previously were not detected. Fixes bug 23082; bugfix on 0.2.0.10-alpha.
Minor bugfixes (onion service v3, client):
Stop logging a "BUG()" warning and stacktrace when we find a SOCKS connection waiting for a descriptor that we actually have in the cache. It turns out that this can actually happen, though it is rare. Now, tor will recover and retry the descriptor. Fixes bug 28669; bugfix on 0.3.2.4-alpha.
Minor bugfixes (onion services):
Avoid crashing if ClientOnionAuthDir (incorrectly) contains more than one private key for a hidden service. Fixes bug 29040; bugfix on 0.3.5.1-alpha.
In hs_cache_store_as_client() log an HSDesc we failed to parse at "debug" level. Tor used to log it as a warning, which caused very long log lines to appear for some users. Fixes bug 29135; bugfix on 0.3.2.1-alpha.
Stop logging "Tried to establish rendezvous on non-OR circuit..." as a warning. Instead, log it as a protocol warning, because there is nothing that relay operators can do to fix it. Fixes bug 29029; bugfix on 0.2.5.7-rc.
Minor bugfixes (periodic events):
Refrain from calling routerlist_remove_old_routers() from check_descriptor_callback(). Instead, create a new hourly periodic event. Fixes bug 27929; bugfix on 0.2.8.1-alpha.
Minor bugfixes (pluggable transports):
Make sure that data is continously read from standard output and standard error pipes of a pluggable transport child-process, to avoid deadlocking when a pipe's buffer is full. Fixes bug 26360; bugfix on 0.2.3.6-alpha.
Minor bugfixes (rust):
Abort on panic in all build profiles, instead of potentially unwinding into C code. Fixes bug 27199; bugfix on 0.3.3.1-alpha.
Minor bugfixes (scheduler):
When re-adding channels to the pending list, check the correct channel's sched_heap_idx. This issue has had no effect in mainline Tor, but could have led to bugs down the road in improved versions of our circuit scheduling code. Fixes bug 29508; bugfix on 0.3.2.10.
Minor bugfixes (shellcheck):
Look for scripts in their correct locations during "make shellcheck". Previously we had looked in the wrong place during out-of-tree builds. Fixes bug 30263; bugfix on 0.4.0.1-alpha.
Minor bugfixes (single onion services):
Allow connections to single onion services to remain idle without being disconnected. Previously, relays acting as rendezvous points for single onion services were mistakenly closing idle rendezvous circuits after 60 seconds, thinking that they were unused directory-fetching circuits that had served their purpose. Fixes bug 29665; bugfix on 0.2.1.26.
Minor bugfixes (stats):
When ExtraInfoStatistics is 0, stop including PaddingStatistics in relay and bridge extra-info documents. Fixes bug 29017; bugfix on 0.3.1.1-alpha.
Minor bugfixes (testing):
Backport the 0.3.4 src/test/test-network.sh to 0.2.9. We need a recent test-network.sh to use new chutney features in CI. Fixes bug 29703; bugfix on 0.2.9.1-alpha.
Fix a test failure on Windows caused by an unexpected "BUG" warning in our tests for tor_gmtime_r(-1). Fixes bug 29922; bugfix on 0.2.9.3-alpha.
Downgrade some LOG_ERR messages in the address/* tests to warnings. The LOG_ERR messages were occurring when we had no configured network. We were failing the unit tests, because we backported 28668 to 0.3.5.8, but did not backport 29530. Fixes bug 29530; bugfix on 0.3.5.8.
Fix our gcov wrapper script to look for object files at the correct locations. Fixes bug 29435; bugfix on 0.3.5.1-alpha.
Decrease the false positive rate of stochastic probability distribution tests. Fixes bug 29693; bugfix on 0.4.0.1-alpha.
Fix intermittent failures on an adaptive padding test. Fixes one case of bug 29122; bugfix on 0.4.0.1-alpha.
Disable an unstable circuit-padding test that was failing intermittently because of an ill-defined small histogram. Such histograms will be allowed again after 29298 is implemented. Fixes a second case of bug 29122; bugfix on 0.4.0.1-alpha.
Detect and suppress "bug" warnings from the util/time test on Windows. Fixes bug 29161; bugfix on 0.2.9.3-alpha.
Do not log an error-level message if we fail to find an IPv6 network interface from the unit tests. Fixes bug 29160; bugfix on 0.2.7.3-rc.
Instead of relying on hs_free_all() to clean up all onion service objects in test_build_descriptors(), we now deallocate them one by one. This lets Coverity know that we are not leaking memory there and fixes CID 1442277. Fixes bug 28989; bugfix on 0.3.5.1-alpha.
Check the time in the "Expires" header using approx_time(). Fixes bug 30001; bugfix on 0.4.0.4-rc.
Minor bugfixes (TLS protocol):
When classifying a client's selection of TLS ciphers, if the client ciphers are not yet available, do not cache the result. Previously, we had cached the unavailability of the cipher list and never looked again, which in turn led us to assume that the client only supported the ancient V1 link protocol. This, in turn, was causing Stem integration tests to stall in some cases. Fixes bug 30021; bugfix on 0.2.4.8-alpha.
Minor bugfixes (UI):
Lower log level of unlink() errors during bootstrap. Fixes bug 29930; bugfix on 0.4.0.1-alpha.
Minor bugfixes (usability):
Stop saying "Your Guard ..." in pathbias_measure_{use,close}_rate(). Some users took this phrasing to mean that the mentioned guard was under their control or responsibility, which it is not. Fixes bug 28895; bugfix on Tor 0.3.0.1-alpha.
Minor bugfixes (Windows, CI):
Skip the Appveyor 32-bit Windows Server 2016 job, and 64-bit Windows Server 2012 R2 job. The remaining 2 jobs still provide coverage of 64/32-bit, and Windows Server 2016/2012 R2. Also set fast_finish, so failed jobs terminate the build immediately. Fixes bug 29601; bugfix on 0.3.5.4-alpha.
Code simplification and refactoring:
Introduce a connection_dir_buf_add() helper function that detects whether compression is in use, and adds a string accordingly. Resolves issue 28816.
Refactor handle_get_next_bandwidth() to use connection_dir_buf_add(). Implements ticket 29897.
Reimplement NETINFO cell parsing and generation to rely on trunnel-generated wire format handling code. Closes ticket 27325.
Remove unnecessary unsafe code from the Rust macro "cstr!". Closes ticket 28077.
Rework SOCKS wire format handling to rely on trunnel-generated parsing/generation code. Resolves ticket 27620.
Split out bootstrap progress reporting from control.c into a separate file. Part of ticket 27402.
The .may_include files that we use to describe our directory-by- directory dependency structure now describe a noncircular dependency graph over the directories that they cover. Our checkIncludes.py tool now enforces this noncircularity. Closes ticket 28362.
Documentation:
Clarify that Tor performs stream isolation among *Port listeners by default. Resolves issue 29121.
In the manpage entry describing MapAddress torrc setting, use example IP addresses from ranges specified for use in documentation by RFC 5737. Resolves issue 28623.
Mention that you cannot add a new onion service if Tor is already running with Sandbox enabled. Closes ticket 28560.
Improve ControlPort documentation. Mention that it accepts address:port pairs, and can be used multiple times. Closes ticket 28805.
Document the exact output of "tor --version". Closes ticket 28889.
Removed features:
Remove the old check-tor script. Resolves issue 29072.
Stop responding to the 'GETINFO status/version/num-concurring' and 'GETINFO status/version/num-versioning' control port commands, as those were deprecated back in 0.2.0.30. Also stop listing them in output of 'GETINFO info/names'. Resolves ticket 28757.
The scripts used to generate and maintain the list of fallback directories have been extracted into a new "fallback-scripts" repository. Closes ticket 27914.
Testing:
Run shellcheck for scripts in the in scripts/ directory. Closes ticket 28058.
Add unit tests for tokenize_string() and get_next_token() functions. Resolves ticket 27625.
Code simplification and refactoring (onion service v3):
Consolidate the authorized client descriptor cookie computation code from client and service into one function. Closes ticket 27549.
Code simplification and refactoring (shell scripts):
Cleanup scan-build.sh to silence shellcheck warnings. Closes ticket 28007.
Fix issues that shellcheck found in chutney-git-bisect.sh. Resolves ticket 28006.
Fix issues that shellcheck found in updateRustDependencies.sh. Resolves ticket 28012.
Fix shellcheck warnings in cov-diff script. Resolves issue 28009.
Fix shellcheck warnings in run_calltool.sh. Resolves ticket 28011.
Fix shellcheck warnings in run_trunnel.sh. Resolves issue 28010.
Fix shellcheck warnings in scripts/test/coverage. Resolves issue 28008.

New in Tor 0.3.5.7 (Jan 8, 2019)

New in Tor 0.3.4.8 (Sep 11, 2018)

New in Tor 0.3.4.7 RC (Aug 25, 2018)

Minor features (bug workaround):
Compile correctly on systems that provide the C11 stdatomic.h header, but where C11 atomic functions don't actually compile. Closes ticket 26779; workaround for Debian issue 903709.
Minor features (continuous integration):
Backport Travis rust distcheck to 0.3.3. Closes ticket 24629.
Enable macOS builds in our Travis CI configuration. Closes ticket 24629.
Install libcap-dev and libseccomp2-dev so these optional dependencies get tested on Travis CI. Closes ticket 26560.
Only post Appveyor IRC notifications when the build fails. Implements ticket 27275.
Run asciidoc during Travis CI. Implements ticket 27087.
Use ccache in our Travis CI configuration. Closes ticket 26952.
Minor features (continuous integration, rust):
Use cargo cache in our Travis CI configuration. Closes ticket 26952.
Minor features (directory authorities):
Authorities no longer vote to make the subprotocol version "LinkAuth=1" a requirement: it is unsupportable with NSS, and hasn't been needed since Tor 0.3.0.1-alpha. Closes ticket 27286.
Minor features (geoip):
Update geoip and geoip6 to the August 7 2018 Maxmind GeoLite2 Country database. Closes ticket 27089.
Minor bugfixes (compilation, windows):
Don't link or search for pthreads when building for Windows, even if we are using build environment (like mingw) that provides a pthreads library. Fixes bug 27081; bugfix on 0.1.0.1-rc.
Minor bugfixes (continuous integration):
Improve Appveyor CI IRC logging. Generate correct branches and URLs for pull requests and tags. Use unambiguous short commits. Fixes bug 26979; bugfix on master.
Build with zstd on macOS. Fixes bug 27090; bugfix on 0.3.1.5-alpha.
Pass the module flags to distcheck configure, and log the flags before running configure. (Backported to 0.2.9 and later as a precaution.) Fixes bug 27088; bugfix on 0.3.4.1-alpha.
Minor bugfixes (in-process restart):
Always call tor_free_all() when leaving tor_run_main(). When we did not, restarting tor in-process would cause an assertion failure. Fixes bug 26948; bugfix on 0.3.3.1-alpha.
Minor bugfixes (linux seccomp2 sandbox):
Fix a bug in out sandboxing rules for the openat() syscall. Previously, no openat() call would be permitted, which would break filesystem operations on recent glibc versions. Fixes bug 25440; bugfix on 0.2.9.15. Diagnosis and patch from Daniel Pinto.
Minor bugfixes (onion services):
Fix bug that causes services to not ever rotate their descriptors if they were getting SIGHUPed often. Fixes bug 26932; bugfix on 0.3.2.1-alpha.
Minor bugfixes (portability):
Fix compilation of the unit tests on GNU/Hurd, which does not define PATH_MAX. Fixes bug 26873; bugfix on 0.3.3.1-alpha. Patch from "paulusASol".
Minor bugfixes (rust):
Backport test_rust.sh from master. Fixes bug 26497; bugfix on 0.3.1.5-alpha.
Consistently use ../../.. as a fallback for $abs_top_srcdir in test_rust.sh. Fixes bug 27093; bugfix on 0.3.4.3-alpha.
Protover parsing was accepting the presence of whitespace in version strings, which the C implementation would choke on, e.g. "Desc=1t,2". Fixes bug 27177; bugfix on 0.3.3.5-rc.
Protover parsing was ignoring a 2nd hyphen and everything after it, accepting entries like "Link=1-5-foo". Fixes bug 27164; bugfix on 0.3.3.1-alpha.
Stop setting $CARGO_HOME. cargo will use the user's $CARGO_HOME, or $HOME/.cargo by default. Fixes bug 26497; bugfix on 0.3.1.5-alpha.
cd to ${abs_top_builddir}/src/rust before running cargo in src/test/test_rust.sh. This makes the working directory consistent between builds and tests. Fixes bug 26497; bugfix on 0.3.3.2-alpha.
Minor bugfixes (testing, bootstrap):
When calculating bootstrap progress, check exit policies and the exit flag. Previously, Tor would only check the exit flag, which caused race conditions in small and fast networks like chutney. Fixes bug 27236; bugfix on 0.2.6.3-alpha.
Minor bugfixes (testing, openssl compatibility):
Our "tortls/cert_matches_key" unit test no longer relies on OpenSSL internals. Previously, it relied on unsupported OpenSSL behavior in a way that caused it to crash with OpenSSL 1.0.2p. Fixes bug 27226; bugfix on 0.2.5.1-alpha.
Minor bugfixes (Windows, compilation):
Silence a compilation warning on MSVC 2017 and clang-cl. Fixes bug 27185; bugfix on 0.2.2.2-alpha.

New in Tor 0.3.4.6 RC (Aug 8, 2018)

Major bug fixes (event scheduler):
When we enable a periodic event, schedule it in the event loop rather than running it immediately. Previously, we would re-run periodic events immediately in the middle of (for example) changing our options, with unpredictable effects. Fixes bug 27003; bugfix on 0.3.4.1-alpha.
Minor features (compilation):
When building Tor, prefer to use Python 3 over Python 2, and more recent (contemplated) versions over older ones. Closes ticket 26372.
Minor features (geoip):
Update geoip and geoip6 to the July 3 2018 Maxmind GeoLite2 Country database. Closes ticket 26674.
Minor features (Rust, portability):
Rust cross-compilation is now supported. Closes ticket 25895.
Minor bug fixes (compilation):
Fix a compilation warning on some versions of GCC when building code that calls routerinfo_get_my_routerinfo() twice, assuming that the second call will succeed if the first one did. Fixes bug 26269; bugfix on 0.2.8.2-alpha.
Minor bug fixes (controller):
Report the port correctly when a port is configured to bind to "auto". Fixes bug 26568; bugfix on 0.3.4.1-alpha.
Parse the "HSADDRESS=" parameter in HSPOST commands properly. Previously, it was misparsed and ignored. Fixes bug 26523; bugfix on 0.3.3.1-alpha. Patch by "akwizgran".
Minor bug fixes (correctness, flow control):
Upon receiving a stream-level SENDME cell, verify that our window has not grown too large. Fixes bug 26214; bugfix on svn r54 (pre-0.0.1)
Minor bug fixes (memory, correctness):
Fix a number of small memory leaks identified by coverity. Fixes bug 26467; bugfix on numerous Tor versions.
Minor bug fixes (portability):
Avoid a compilation error in test_bwmgt.c on Solaris 10. Fixes bug 26994; bugfix on 0.3.4.1-alpha.
Minor bug fixes (testing, compatibility):
When running the ntor_ref.py and hs_ntor_ref.py tests, make sure only to pass strings (rather than "bytes" objects) to the Python subprocess module. Python 3 on Windows seems to require this. Fixes bug 26535; bugfix on 0.2.5.5-alpha (for ntor_ref.py) and 0.3.1.1-alpha (for hs_ntor_ref.py).

New in Tor 0.3.3.9 (Jul 16, 2018)

New in Tor 0.3.4.4 RC (Jul 13, 2018)

Tor 0.3.4.4-rc fixes several small compilation, portability, and correctness issues in previous versions of Tor. This version is a release candidate: if no serious bugs are found, we expect that the stable 0.3.4 release will be (almost) the same as this release.
Minor features (compilation):
When building Tor, prefer to use Python 3 over Python 2, and more recent (contemplated) versions over older ones. Closes ticket 26372.
Minor features (geoip):
Update geoip and geoip6 to the July 3 2018 Maxmind GeoLite2 Country database. Closes ticket 26674.
Minor features (Rust, portability):
Rust cross-compilation is now supported. Closes ticket 25895.
Minor bug fixes (compilation):
Fix a compilation warning on some versions of GCC when building code that calls routerinfo_get_my_routerinfo() twice, assuming that the second call will succeed if the first one did. Fixes bug 26269; bugfix on 0.2.8.2-alpha.
Minor bug fixes (control port):
Report the port correctly when a port is configured to bind to "auto". Fixes bug 26568; bugfix on 0.3.4.1-alpha.
Handle the HSADDRESS= argument to the HSPOST command properly. (Previously, this argument was misparsed and thus ignored.) Fixes bug 26523; bugfix on 0.3.3.1-alpha. Patch by "akwizgran".
Minor bug fixes (correctness, flow control):
Upon receiving a stream-level SENDME cell, verify that our window has not grown too large. Fixes bug 26214; bug fix on svn r54 (pre-0.0.1).
Minor bug fixes (memory, correctness):
Fix a number of small memory leaks identified by coverity. Fixes bug 26467; bugfix on numerous Tor versions.
Minor bug fixes (testing, compatibility):
When running the hs_ntor_ref.py test, make sure only to pass strings (rather than "bytes" objects) to the Python subprocess module. Python 3 on Windows seems to require this. Fixes bug 26535; bug fix on 0.3.1.1-alpha.
When running the ntor_ref.py test, make sure only to pass strings (rather than "bytes" objects) to the Python subprocess module. Python 3 on Windows seems to require this. Fixes bug 26535; bug fix on 0.2.5.5-alpha.

New in Tor 0.3.3.8 (Jul 10, 2018)

Tor 0.3.3.8 backports several changes from the 0.3.4.x series, including fixes for a memory leak affecting directory authorities.
Major bug fixes (directory authority, backport from 0.3.4.3-alpha):
Stop leaking memory on directory authorities when planning to vote. This bug was crashing authorities by exhausting their memory. Fixes bug 26435; bugfix on 0.3.3.6.
Major bug fixes (rust, testing, backport from 0.3.4.3-alpha):
Make sure that failing tests in Rust will actually cause the build to fail: previously, they were ignored. Fixes bug 26258; bugfix on 0.3.3.4-alpha.
Minor features (compilation, backport from 0.3.4.4-rc):
When building Tor, prefer to use Python 3 over Python 2, and more recent (contemplated) versions over older ones. Closes ticket 26372.
Minor features (geoip):
Update geoip and geoip6 to the July 3 2018 Maxmind GeoLite2 Country database. Closes ticket 26674.
Minor features (relay, diagnostic, backport from 0.3.4.3-alpha):
Add several checks to detect whether Tor relays are uploading their descriptors without specifying why they regenerated them. Diagnostic for ticket 25686.
Minor bug fixes (circuit path selection, backport from 0.3.4.1-alpha):
Don't count path selection failures as circuit build failures. This change should eliminate cases where Tor blames its guard or the network for situations like insufficient microdescriptors and/or overly restrictive torrc settings. Fixes bug 25705; bugfix on 0.3.3.1-alpha.
Minor bug fixes (compilation, backport from 0.3.4.4-rc):
Fix a compilation warning on some versions of GCC when building code that calls routerinfo_get_my_routerinfo() twice, assuming that the second call will succeed if the first one did. Fixes bug 26269; bugfix on 0.2.8.2-alpha.
Minor bug fixes (control port, backport from 0.3.4.4-rc):
Handle the HSADDRESS= argument to the HSPOST command properly. (Previously, this argument was misparsed and thus ignored.) Fixes bug 26523; bugfix on 0.3.3.1-alpha. Patch by "akwizgran".
Minor bug fixes (memory, correctness, backport from 0.3.4.4-rc):
Fix a number of small memory leaks identified by coverity. Fixes bug 26467; bugfix on numerous Tor versions.
Minor bug fixes (relay, backport from 0.3.4.3-alpha):
Relays now correctly block attempts to re-extend to the previous relay by Ed25519 identity. Previously they would warn in this case, but not actually reject the attempt. Fixes bug 26158; bugfix on 0.3.0.1-alpha.
Minor bug fixes (restart-in-process, backport from 0.3.4.1-alpha):
When shutting down, Tor now clears all the flags in the control.c module. This should prevent a bug where authentication cookies are not generated on restart. Fixes bug 25512; bugfix on 0.3.3.1-alpha.
Minor bug fixes (testing, compatibility, backport from 0.3.4.4-rc):
When running the hs_ntor_ref.py test, make sure only to pass strings (rather than "bytes" objects) to the Python subprocess module. Python 3 on Windows seems to require this. Fixes bug 26535; bugfix on 0.3.1.1-alpha.
When running the ntor_ref.py test, make sure only to pass strings (rather than "bytes" objects) to the Python subprocess module. Python 3 on Windows seems to require this. Fixes bug 26535; bugfix on 0.2.5.5-alpha.

New in Tor 0.3.4.2 Alpha (Jun 13, 2018)

Directory authority changes:
Add an IPv6 address for the "dannenberg" directory authority. Closes ticket 26343.
Major bugfixes (security, directory authority, denial-of-service, also in 0.3.3.6):
Fix a bug that could have allowed an attacker to force a directory authority to use up all its RAM by passing it a maliciously crafted protocol versions string. Fixes bug 25517; bugfix on 0.2.9.4-alpha. This issue is also tracked as TROVE-2018-005.
Minor features (continuous integration):
Add the necessary configuration files for continuous integration testing on Windows, via the Appveyor platform. Closes ticket 25549. Patches from Marcin Cieślak and Isis Lovecruft.
Minor features (geoip):
Update geoip and geoip6 to the June 7 2018 Maxmind GeoLite2 Country database. Closes ticket 26351.
Minor bugfixes (compatibility, openssl):
Work around a change in OpenSSL 1.1.1 where return values that would previously indicate "no password" now indicate an empty password. Without this workaround, Tor instances running with OpenSSL 1.1.1 would accept descriptors that other Tor instances would reject. Fixes bug 26116; bugfix on 0.2.5.16.
Minor bugfixes (compilation):
Silence unused-const-variable warnings in zstd.h with some GCC versions. Fixes bug 26272; bugfix on 0.3.1.1-alpha.
Fix compilation when using OpenSSL 1.1.0 with the "no-deprecated" flag enabled. Fixes bug 26156; bugfix on 0.3.4.1-alpha.
Avoid a compiler warning when casting the return value of smartlist_len() to double with DEBUG_SMARTLIST enabled. Fixes bug 26283; bugfix on 0.2.4.10-alpha.
Minor bugfixes (control port):
Do not count 0-length RELAY_COMMAND_DATA cells as valid data in CIRC_BW events. Previously, such cells were counted entirely in the OVERHEAD field. Now they are not. Fixes bug 26259; bugfix on 0.3.4.1-alpha.
Minor bugfixes (controller):
Improve accuracy of the BUILDTIMEOUT_SET control port event's TIMEOUT_RATE and CLOSE_RATE fields. (We were previously miscounting the total number of circuits for these field values.) Fixes bug 26121; bugfix on 0.3.3.1-alpha.
Minor bugfixes (hardening):
Prevent a possible out-of-bounds smartlist read in protover_compute_vote(). Fixes bug 26196; bugfix on 0.2.9.4-alpha.
Minor bugfixes (onion services):
Fix a bug that blocked the creation of ephemeral v3 onion services. Fixes bug 25939; bugfix on 0.3.4.1-alpha.
Minor bugfixes (test coverage tools):
Update our "cov-diff" script to handle output from the latest version of gcov, and to remove extraneous timestamp information from its output. Fixes bugs 26101 and 26102; bugfix on 0.2.5.1-alpha.

New in Tor 0.3.3.7 (Jun 13, 2018)

New in Tor 0.3.3.6 (May 23, 2018)

backports several important fixes from the 0.3.4.1-alpha.
The Tor 0.3.3 series includes controller support and other
improvements for v3 onion services, official support for embedding Tor
within other applications, and our first non-trivial module written in
the Rust programming language. (Rust is still not enabled by default
when building Tor.) And as usual, there are numerous other smaller
bug fixes, features, and improvements.
Below are the changes since 0.3.2.10. For a list of only the changes
since 0.3.3.5-rc, see the ChangeLog file.
New system requirements:
When built with Rust, Tor now depends on version 0.2.39 of the libc crate. Closes tickets 25310 and 25664.
Major features (embedding):
There is now a documented stable API for programs that need to embed Tor. See tor_api.h for full documentation and known bugs. Closes ticket 23684.
Tor now has support for restarting in the same process. Controllers that run Tor using the "tor_api.h" interface can now restart Tor after Tor has exited. This support is incomplete, however: we fixed crash bugs that prevented it from working at all, but many bugs probably remain, including a possibility of security issues. Implements ticket 24581.
Major features (IPv6, directory documents):
Add consensus method 27, which adds IPv6 ORPorts to the microdesc consensus. This information makes it easier for IPv6 clients to bootstrap and choose reachable entry guards. Implements ticket 23826.
Add consensus method 28, which removes IPv6 ORPorts from microdescriptors. Now that the consensus contains IPv6 ORPorts, they are redundant in microdescs. This change will be used by Tor clients on 0.2.8.x and later. (That is to say, with all Tor clients that have IPv6 bootstrap and guard support.) Implements ticket 23828.
Expand the documentation for AuthDirHasIPv6Connectivity when it is set by different numbers of authorities. Fixes 23870 on 0.2.4.1-alpha.
Major features (onion service v3, control port):
The control port now supports commands and events for v3 onion services. It is now possible to create ephemeral v3 services using ADD_ONION. Additionally, several events (HS_DESC, HS_DESC_CONTENT, CIRC and CIRC_MINOR) and commands (GETINFO, HSPOST, ADD_ONION and DEL_ONION) have been extended to support v3 onion services. Closes ticket 20699; implements proposal 284.
Major features (onion services):
Provide torrc options to pin the second and third hops of onion service circuits to a list of nodes. The option HSLayer2Guards pins the second hop, and the option HSLayer3Guards pins the third hop. These options are for use in conjunction with experiments with "vanguards" for preventing guard enumeration attacks. Closes ticket 13837.
When v3 onion service clients send introduce cells, they now include the IPv6 address of the rendezvous point, if it has one. Current v3 onion services running 0.3.2 ignore IPv6 addresses, but in future Tor versions, IPv6-only v3 single onion services will be able to use IPv6 addresses to connect directly to the rendezvous point. Closes ticket 23577. Patch by Neel Chauhan.
Major features (relay):
Implement an option, ReducedExitPolicy, to allow an Tor exit relay operator to use a more reasonable ("reduced") exit policy, rather than the default one. If you want to run an exit node without thinking too hard about which ports to allow, this one is for you. Closes ticket 13605. Patch from Neel Chauhan.
Major features (rust, portability, experimental):
Tor now ships with an optional implementation of one of its smaller modules (protover.c) in the Rust programming language. To try it out, install a Rust build environment, and configure Tor with "--enable-rust --enable-cargo-online-mode". This should not cause any user-visible changes, but should help us gain more experience with Rust, and plan future Rust integration work. Implementation by Chelsea Komlo. Closes ticket 22840.
Major bug fixes (directory authorities, security, backport from 0.3.4.1-alpha):
When directory authorities read a zero-byte bandwidth file, they would previously log a warning with the contents of an uninitialised buffer. They now log a warning about the empty file instead. Fixes bug 26007; bugfix on 0.2.2.1-alpha.
Major bug fixes (security, directory authority, denial-of-service):
Fix a bug that could have allowed an attacker to force a directory authority to use up all its RAM by passing it a maliciously crafted protocol versions string. Fixes bug 25517; bugfix on 0.2.9.4-alpha. This issue is also tracked as TROVE-2018-005.
Major bug fixes (crash, backport from 0.3.4.1-alpha):
Avoid a rare assertion failure in the circuit build timeout code if we fail to allow any circuits to actually complete. Fixes bug 25733; bugfix on 0.2.2.2-alpha.
Major bug fixes (netflow padding):
Stop adding unneeded channel padding right after we finish flushing to a connection that has been trying to flush for many seconds. Instead, treat all partial or complete flushes as activity on the channel, which will defer the time until we need to add padding. This fix should resolve confusing and scary log messages like "Channel padding timeout scheduled 221453ms in the past." Fixes bug 22212; bugfix on 0.3.1.1-alpha.
Major bug fixes (networking):
Tor will no longer reject IPv6 address strings from Tor Browser when they are passed as hostnames in SOCKS5 requests. Fixes bug 25036, bugfix on Tor 0.3.1.2.
Major bug fixes (onion service, backport from 0.3.4.1-alpha):
Correctly detect when onion services get disabled after HUP. Fixes bug 25761; bugfix on 0.3.2.1.
Major bug fixes (performance, load balancing):
Directory authorities no longer vote in favor of the Guard flag for relays without directory support. Starting in Tor 0.3.0.1-alpha, clients have been avoiding using such relays in the Guard position, leading to increasingly broken load balancing for the 5%-or-so of Guards that don't advertise directory support. Fixes bug 22310; bugfix on 0.3.0.6.
Major bug fixes (relay):
If we have failed to connect to a relay and received a connection refused, timeout, or similar error (at the TCP level), do not try that same address/port again for 60 seconds after the failure has occurred. Fixes bug 24767; bugfix on 0.0.6.
Major bug fixes (relay, denial of service, backport from 0.3.4.1-alpha):
Impose a limit on circuit cell queue size. The limit can be controlled by a consensus parameter. Fixes bug 25226; bugfix on 0.2.4.14-alpha.
Minor features (cleanup):
Tor now deletes the CookieAuthFile and ExtORPortCookieAuthFile when it stops. Closes ticket 23271.
Minor features (compatibility, backport from 0.3.4.1-alpha):
Avoid some compilation warnings with recent versions of LibreSSL. Closes ticket 26006.
Minor features (config options):
Change the way the default value for MaxMemInQueues is calculated. We now use 40% of the hardware RAM if the system has 8 GB RAM or more. Otherwise we use the former value of 75%. Closes ticket 24782.
Minor features (continuous integration):
Update the Travis CI configuration to use the stable Rust channel, now that we have decided to require that. Closes ticket 25714.
Minor features (continuous integration, backport from 0.3.4.1-alpha):
Our .travis.yml configuration now includes support for testing the results of "make distcheck". (It's not uncommon for "make check" to pass but "make distcheck" to fail.) Closes ticket 25814.
Our Travis CI configuration now integrates with the Coveralls coverage analysis tool. Closes ticket 25818.
Minor features (defensive programming):
Most of the functions in Tor that free objects have been replaced with macros that free the objects and set the corresponding pointers to NULL. This change should help prevent a large class of dangling pointer bugs. Closes ticket 24337.
Where possible, the tor_free() macro now only evaluates its input once. Part of ticket 24337.
Check that microdesc ed25519 ids are non-zero in node_get_ed25519_id() before returning them. Implements ticket 24001, patch by "aruna1234".
Minor features (directory authority):
When directory authorities are unable to add signatures to a pending consensus, log the reason why. Closes ticket 24849.
Minor features (embedding):
Tor can now start with a preauthenticated control connection created by the process that launched it. This feature is meant for use by programs that want to launch and manage a Tor process without allowing other programs to manage it as well. For more information, see the __OwningControllerFD option documented in control-spec.txt. Closes ticket 23900.
On most errors that would cause Tor to exit, it now tries to return from the tor_main() function, rather than calling the system exit() function. Most users won't notice a difference here, but it should be significant for programs that run Tor inside a separate thread: they should now be able to survive Tor's exit conditions rather than having Tor shut down the entire process. Closes ticket 23848.
Applications that want to embed Tor can now tell Tor not to register any of its own POSIX signal handlers, using the __DisableSignalHandlers option. Closes ticket 24588.
Minor features (fallback directory list):
Avoid selecting fallbacks that change their IP addresses too often. Select more fallbacks by ignoring the Guard flag, and allowing lower cutoffs for the Running and V2Dir flags. Also allow a lower bandwidth, and a higher number of fallbacks per operator (5% of the list). Implements ticket 24785.
Update the fallback whitelist and blacklist based on opt-ins and relay changes. Closes tickets 22321, 24678, 22527, 24135, and 24695.
Minor features (fallback directory mirror configuration):
Add a nickname to each fallback in a C comment. This makes it easier for operators to find their relays, and allows stem to use nicknames to identify fallbacks. Implements ticket 24600.
Add a type and version header to the fallback directory mirror file. Also add a delimiter to the end of each fallback entry. This helps external parsers like stem and Relay Search. Implements ticket 24725.
Add an extrainfo cache flag for each fallback in a C comment. This allows stem to use fallbacks to fetch extra-info documents, rather than using authorities. Implements ticket 22759.
Add the generateFallbackDirLine.py script for automatically generating fallback directory mirror lines from relay fingerprints. No more typos! Add the lookupFallbackDirContact.py script for automatically looking up operator contact info from relay fingerprints. Implements ticket 24706, patch by teor and atagar.
Reject any fallback directory mirror that serves an expired consensus. Implements ticket 20942, patch by "minik".
Remove commas and equals signs from external string inputs to the fallback list. This avoids format confusion attacks. Implements ticket 24726.
Remove the "weight=10" line from fallback directory mirror entries. Ticket 24681 will maintain the current fallback weights by changing Tor's default fallback weight to 10. Implements ticket 24679.
Stop logging excessive information about fallback netblocks. Implements ticket 24791.
Minor features (forward-compatibility):
If a relay supports some link authentication protocol that we do not recognize, then include that relay's ed25519 key when telling other relays to extend to it. Previously, we treated future versions as if they were too old to support ed25519 link authentication. Closes ticket 20895.
Minor features (geoip):
Update geoip and geoip6 to the May 1 2018 Maxmind GeoLite2 Country database. Closes ticket 26104.
Minor features (heartbeat):
Add onion service information to our heartbeat logs, displaying stats about the activity of configured onion services. Closes ticket 24896.
Minor features (instrumentation, development):
Add the MainloopStats option to allow developers to get instrumentation information from the main event loop via the heartbeat messages. We hope to use this to improve Tor's behavior when it's trying to sleep. Closes ticket 24605.
Minor features (IPv6):
Make IPv6-only clients wait for microdescs for relays, even if we were previously using descriptors (or were using them as a bridge) and have a cached descriptor for them. Implements ticket 23827.
When a consensus has IPv6 ORPorts, make IPv6-only clients use them, rather than waiting to download microdescriptors. Implements ticket 23827.
Minor features (log messages):
Improve log message in the out-of-memory handler to include information about memory usage from the different compression backends. Closes ticket 25372.
Improve a warning message that happens when we fail to re-parse an old router because of an expired certificate. Closes ticket 20020.
Make the log more quantitative when we hit MaxMemInQueues threshold exposing some values. Closes ticket 24501.
Minor features (logging):
Clarify the log messages produced when getrandom() or a related entropy-generation mechanism gives an error. Closes ticket 25120.
Added support for the Android logging subsystem. Closes ticket 24362.
Minor features (performance):
Support predictive circuit building for onion service circuits with multiple layers of guards. Closes ticket 23101.
Use stdatomic.h where available, rather than mutexes, to implement atomic_counter_t. Closes ticket 23953.
Minor features (performance, 32-bit):
Improve performance on 32-bit systems by avoiding 64-bit division when calculating the timestamp in milliseconds for channel padding computations. Implements ticket 24613.
Improve performance on 32-bit systems by avoiding 64-bit division when timestamping cells and buffer chunks for OOM calculations. Implements ticket 24374.
Minor features (performance, OSX, iOS):
Use the mach_approximate_time() function (when available) to implement coarse monotonic time. Having a coarse time function should avoid a large number of system calls, and improve performance slightly, especially under load. Closes ticket 24427.
Minor features (performance, windows):
Improve performance on Windows Vista and Windows 7 by adjusting TCP send window size according to the recommendation from SIO_IDEAL_SEND_BACKLOG_QUERY. Closes ticket 22798. Patch from Vort.
Minor features (sandbox):
Explicitly permit the poll() system call when the Linux seccomp2-based sandbox is enabled: apparently, some versions of libc use poll() when calling getpwnam(). Closes ticket 25313.
Minor features (storage, configuration):
Users can store cached directory documents somewhere other than the DataDirectory by using the CacheDirectory option. Similarly, the storage location for relay's keys can be overridden with the KeyDirectory option. Closes ticket 22703.
Minor features (testing):
Add a "make test-rust" target to run the rust tests only. Closes ticket 25071.
Minor features (testing, debugging, embedding):
For development purposes, Tor now has a mode in which it runs for a few seconds, then stops, and starts again without exiting the process. This mode is meant to help us debug various issues with ticket 23847. To use this feature, compile with --enable-restart-debugging, and set the TOR_DEBUG_RESTART environment variable. This is expected to crash a lot, and is really meant for developers only. It will likely be removed in a future release. Implements ticket 24583.
Minor bug fixes (build, rust):
Fix output of autoconf checks to display success messages for Rust dependencies and a suitable rustc compiler version. Fixes bug 24612; bugfix on 0.3.1.3-alpha.
Don't pass the --quiet option to cargo: it seems to suppress some errors, which is not what we want to do when building. Fixes bug 24518; bugfix on 0.3.1.7.
Build correctly when building from outside Tor's source tree with the TOR_RUST_DEPENDENCIES option set. Fixes bug 22768; bugfix on 0.3.1.7.
Minor bug fixes (C correctness):
Fix a very unlikely (impossible, we believe) null pointer dereference. Fixes bug 25629; bugfix on 0.2.9.15. Found by Coverity; this is CID 1430932.
Minor bug fixes (channel, client):
Better identify client connection when reporting to the geoip client cache. Fixes bug 24904; bugfix on 0.3.1.7.
Minor bug fixes (circuit, cannibalization):
Don't cannibalize preemptively-built circuits if we no longer recognize their first hop. This situation can happen if our Guard relay went off the consensus after the circuit was created. Fixes bug 24469; bugfix on 0.0.6.
Minor bug fixes (client, backport from 0.3.4.1-alpha):
Don't consider Tor running as a client if the ControlPort is open, but no actual client ports are open. Fixes bug 26062; bugfix on 0.2.9.4-alpha.
Minor bug fixes (compilation):
Fix a C99 compliance issue in our configuration script that caused compilation issues when compiling Tor with certain versions of xtools. Fixes bug 25474; bugfix on 0.3.2.5-alpha.
Minor bug fixes (controller):
Restore the correct operation of the RESOLVE command, which had been broken since we added the ability to enable/disable DNS on specific listener ports. Fixes bug 25617; bugfix on 0.2.9.3-alpha.
Avoid a (nonfatal) assertion failure when extending a one-hop circuit from the controller to become a multihop circuit. Fixes bug 24903; bugfix on 0.2.5.2-alpha.
Minor bug fixes (correctness):
Remove a nonworking, unnecessary check to see whether a circuit hop's identity digest was set when the circuit failed. Fixes bug 24927; bugfix on 0.2.4.4-alpha.
Minor bug fixes (correctness, client, backport from 0.3.4.1-alpha):
Upon receiving a malformed connected cell, stop processing the cell immediately. Previously we would mark the connection for close, but continue processing the cell as if the connection were open. Fixes bug 26072; bugfix on 0.2.4.7-alpha.
Minor bug fixes (directory authorities, IPv6):
When creating a routerstatus (vote) from a routerinfo (descriptor), set the IPv6 address to the unspecified IPv6 address, and explicitly initialize the port to zero. Fixes bug 24488; bugfix on 0.2.4.1-alpha.
Minor bug fixes (documentation):
Document that the PerConnBW{Rate,Burst} options will fall back to their corresponding consensus parameters only if those parameters are set. Previously we had claimed that these values would always be set in the consensus. Fixes bug 25296; bugfix on 0.2.2.7-alpha.
Minor bug fixes (documentation, backport from 0.3.4.1-alpha):
Stop saying in the manual that clients cache ipv4 dns answers from exit relays. We haven't used them since 0.2.6.3-alpha, and in ticket 24050 we stopped even caching them as of 0.3.2.6-alpha, but we forgot to say so in the man page. Fixes bug 26052; bugfix on 0.3.2.6-alpha.
Minor bug fixes (exit relay DNS retries):
Re-attempt timed-out DNS queries 3 times before failure, since our timeout is 5 seconds for them, but clients wait 10-15. Also allow slightly more timeouts per resolver when an exit has multiple resolvers configured. Fixes bug 21394; bugfix on 0.3.1.9.
Minor bug fixes (fallback directory mirrors):
Make updateFallbackDirs.py search harder for python. (Some OSs don't put it in /usr/bin.) Fixes bug 24708; bugfix on 0.2.8.1-alpha.
Minor bug fixes (hibernation, bandwidth accounting, shutdown):
When hibernating, close connections normally and allow them to flush. Fixes bug 23571; bugfix on 0.2.4.7-alpha. Also fixes bug 7267.
Do not attempt to launch self-reachability tests when entering hibernation. Fixes a case of bug 12062; bugfix on 0.0.9pre5.
Resolve several bugs related to descriptor fetching on bridge clients with bandwidth accounting enabled. (This combination is not recommended!) Fixes a case of bug 12062; bugfix on 0.2.0.3-alpha.
When hibernating, do not attempt to launch DNS checks. Fixes a case of bug 12062; bugfix on 0.1.2.2-alpha.
When hibernating, do not try to upload or download descriptors. Fixes a case of bug 12062; bugfix on 0.0.9pre5.
Minor bug fixes (IPv6, bridges):
Tor now always sets IPv6 preferences for bridges. Fixes bug 24573; bugfix on 0.2.8.2-alpha.
Tor now sets IPv6 address in the routerstatus as well as in the router descriptors when updating addresses for a bridge. Closes ticket 24572; bugfix on 0.2.4.5-alpha. Patch by "ffmancera".
Minor bug fixes (Linux seccomp2 sandbox):
When running with the sandbox enabled, reload configuration files correctly even when %include was used. Previously we would crash. Fixes bug 22605; bugfix on 0.3.1. Patch from Daniel Pinto.
Minor bug fixes (Linux seccomp2 sandbox, backport from 0.3.4.1-alpha):
Allow the nanosleep() system call, which glibc uses to implement sleep() and usleep(). Fixes bug 24969; bugfix on 0.2.5.1-alpha.
Minor bug fixes (logging):
Fix a (mostly harmless) race condition when invoking LOG_PROTOCOL_WARN message from a subthread while the torrc options are changing. Fixes bug 23954; bugfix on 0.1.1.9-alpha.
Minor bug fixes (man page, SocksPort):
Remove dead code from the old "SocksSocket" option, and rename SocksSocketsGroupWritable to UnixSocksGroupWritable. The old option still works, but is deprecated. Fixes bug 24343; bugfix on 0.2.6.3.
Minor bug fixes (memory leaks):
Avoid possible at-exit memory leaks related to use of Libevent's event_base_once() function. (This function tends to leak memory if the event_base is closed before the event fires.) Fixes bug 24584; bugfix on 0.2.8.1-alpha.
Fix a harmless memory leak in tor-resolve. Fixes bug 24582; bugfix on 0.2.1.1-alpha.
Minor bug fixes (network IPv6 test):
Tor's test scripts now check if "ping -6 ::1" works when the user runs "make test-network-all". Fixes bug 24677; bugfix on 0.2.9.3-alpha. Patch by "ffmancera".
Minor bug fixes (networking):
string_is_valid_hostname() will not consider IP strings to be valid hostnames. Fixes bug 25055; bugfix on Tor 0.2.5.5.
Minor bug fixes (onion service v3):
Avoid an assertion failure when the next onion service descriptor rotation type is out of sync with the consensus's valid-after time. Instead, log a warning message with extra information, so we can better hunt down the cause of this assertion. Fixes bug 25306; bugfix on 0.3.2.1-alpha.
Minor bug fixes (onion service, backport from 0.3.4.1-alpha):
Fix a memory leak when a v3 onion service is configured and gets a SIGHUP signal. Fixes bug 25901; bugfix on 0.3.2.1-alpha.
When parsing the descriptor signature, look for the token plus an extra white-space at the end. This is more correct but also will allow us to support new fields that might start with "signature". Fixes bug 26069; bugfix on 0.3.0.1-alpha.
Minor bug fixes (onion services):
If we are configured to offer a single onion service, don't log long-term established one hop rendezvous points in the heartbeat. Fixes bug 25116; bugfix on 0.2.9.6-rc.
Minor bug fixes (performance):
Reduce the number of circuits that will be opened at once during the circuit build timeout phase. This is done by increasing the idle timeout to 3 minutes, and lowering the maximum number of concurrent learning circuits to 10. Fixes bug 24769; bugfix on 0.3.1.1-alpha.
Avoid calling protocol_list_supports_protocol() from inside tight loops when running with cached routerinfo_t objects. Instead, summarize the relevant protocols as flags in the routerinfo_t, as we do for routerstatus_t objects. This change simplifies our code a little, and saves a large amount of short-term memory allocation operations. Fixes bug 25008; bugfix on 0.2.9.4-alpha.
Minor bug fixes (performance, timeouts):
Consider circuits for timeout as soon as they complete a hop. This is more accurate than applying the timeout in circuit_expire_building() because that function is only called once per second, which is now too slow for typical timeouts on the current network. Fixes bug 23114; bugfix on 0.2.2.2-alpha.
Use onion service circuits (and other circuits longer than 3 hops) to calculate a circuit build timeout. Previously, Tor only calculated its build timeout based on circuits that planned to be exactly 3 hops long. With this change, we include measurements from all circuits at the point where they complete their third hop. Fixes bug 23100; bugfix on 0.2.2.2-alpha.
Minor bug fixes (relay, crash, backport from 0.3.4.1-alpha):
Avoid a crash when running with DirPort set but ORPort tuned off. Fixes a case of bug 23693; bugfix on 0.3.1.1-alpha.
Minor bug fixes (Rust FFI):
Fix a minor memory leak which would happen whenever the C code would call the Rust implementation of protover_get_supported_protocols(). This was due to the C version returning a static string, whereas the Rust version newly allocated a CString to pass accross the FFI boundary. Consequently, the C code was not expecting to need to free() what it was given. Fixes bug 25127; bugfix on 0.3.2.1-alpha.
Minor bug fixes (spelling):
Use the "misspell" tool to detect and fix typos throughout the source code. Fixes bug 23650; bugfix on various versions of Tor. Patch from Deepesh Pathak.
Minor bug fixes (testing):
Avoid intermittent test failures due to a test that had relied on onion service introduction point creation finishing within 5 seconds of real clock time. Fixes bug 25450; bugfix on 0.3.1.3-alpha.
Give out Exit flags in bootstrapping networks. Fixes bug 24137; bugfix on 0.2.3.1-alpha.
Minor bug fixes (unit test, monotonic time):
Increase a constant (1msec to 10msec) in the monotonic time test that makes sure the nsec/usec/msec times read are synchronized. This change was needed to accommodate slow systems like armel or when the clock_gettime() is not a VDSO on the running kernel. Fixes bug 25113; bugfix on 0.2.9.1.
Code simplification and refactoring:
Move the list of default directory authorities to its own file. Closes ticket 24854. Patch by "beastr0".
Remove the old (deterministic) directory retry logic entirely: We've used exponential backoff exclusively for some time. Closes ticket 23814.
Remove the unused nodelist_recompute_all_hsdir_indices(). Closes ticket 25108.
Remove a series of counters used to track circuit extend attempts and connection status but that in reality we aren't using for anything other than stats logged by a SIGUSR1 signal. Closes ticket 25163.
Remove /usr/athena from search path in configure.ac. Closes ticket 24363.
Remove duplicate code in node_has_curve25519_onion_key() and node_get_curve25519_onion_key(), and add a check for a zero microdesc curve25519 onion key. Closes ticket 23966, patch by "aruna1234" and teor.
Rewrite channel_rsa_id_group_set_badness to reduce temporary memory allocations with large numbers of OR connections (e.g. relays). Closes ticket 24119.
Separate the function that deletes ephemeral files when Tor stops gracefully.
Small changes to Tor's buf_t API to make it suitable for use as a general-purpose safe string constructor. Closes ticket 22342.
Switch -Wnormalized=id to -Wnormalized=nfkc in configure.ac to avoid source code identifier confusion. Closes ticket 24467.
The tor_git_revision[] constant no longer needs to be redeclared by everything that links against the rest of Tor. Done as part of ticket 23845, to simplify our external API.
We make extend_info_from_node() use node_get_curve25519_onion_key() introduced in ticket 23577 to access the curve25519 public keys rather than accessing it directly. Closes ticket 23760. Patch by Neel Chauhan.
Add a function to log channels' scheduler state changes to aid debugging efforts. Closes ticket 24531.
Documentation:
Improved the documentation of AccountingStart parameter. Closes ticket 23635.
Update the documentation for "Log" to include the current list of logging domains. Closes ticket 25378.
Add documentation on how to build tor with Rust dependencies without having to be online. Closes ticket 22907; bugfix on 0.3.0.3-alpha.
Clarify the behavior of RelayBandwidth{Rate,Burst} with client traffic. Closes ticket 24318.
Document that OutboundBindAddress doesn't apply to DNS requests. Closes ticket 22145. Patch from Aruna Maurya.
Code simplification and refactoring (channels):
Remove the incoming and outgoing channel queues. These were never used, but still took up a step in our fast path.
The majority of the channel unit tests have been rewritten and the code coverage has now been raised to 83.6% for channel.c. Closes ticket 23709.
Remove other dead code from the channel subsystem: All together, this cleanup has removed more than 1500 lines of code overall and adding very little except for unit test.
Code simplification and refactoring (circuit rendezvous):
Split the client-side rendezvous circuit lookup into two functions: one that returns only established circuits and another that returns all kinds of circuits. Closes ticket 23459.
Code simplification and refactoring (controller):
Make most of the variables in networkstatus_getinfo_by_purpose() const. Implements ticket 24489.
Documentation (backport from 0.3.4.1-alpha):
Correct an IPv6 error in the documentation for ExitPolicy. Closes ticket 25857. Patch from "CTassisF".
Documentation (man page):
The HiddenServiceVersion torrc option accepts only one number: either version 2 or 3. Closes ticket 25026; bugfix on 0.3.2.2-alpha.
Documentation (manpage, denial of service):
Provide more detail about the denial-of-service options, by listing each mitigation and explaining how they relate. Closes ticket 25248.

New in Tor 0.3.4.1 Alpha (May 18, 2018)

Tor 0.3.4.1-alpha is the first release in the 0.3.4.x series. It includes refactoring to begin reducing Tor's binary size and idle CPU usage on mobile, along with prep work for new bandwidth scanners, improvements to the experimental "vanguards" feature, and numerous other small features and bug fixes.
New system requirements:
Tor no longer tries to support old operating systems without mmap() or some local equivalent. Apparently, compilation on such systems has been broken for some time, without anybody noticing or complaining. Closes ticket 25398.
Major feature (directory authority, modularization):
The directory authority subsystem has been modularized. The code is now located in src/or/dirauth/, and is compiled in by default. To disable the module, the configure option --disable-module-dirauth has been added. This module may be disabled by default in some future release. Closes ticket 25610.
Major features (main loop, CPU usage):
When Tor is disabled (via DisableNetwork or via hibernation), it no longer needs to run any per-second events. This change should make it easier for mobile applications to disable Tor while the device is sleeping, or Tor is not running. Closes ticket 26063.
Tor no longer enables all of its periodic events by default. Previously, Tor would enable all possible main loop events, regardless of whether it needed them. Furthermore, many of these events are now disabled with Tor is hibernating or DisableNetwork is set. This is a big step towards reducing client CPU usage by reducing the amount of wake-ups the daemon does. Closes ticket 25376 and 25762.
The bandwidth-limitation logic has been refactored so that bandwidth calculations are performed on-demand, rather than every TokenBucketRefillInterval milliseconds. This change should improve the granularity of our bandwidth calculations, and limit the number of times that the Tor process needs to wake up when it is idle. Closes ticket 25373.
Move responsibility for many operations from a once-per-second callback to a callback that is only scheduled as needed. Moving this functionality has allowed us to disable the callback when Tor's network is disabled. Once enough items are removed from our once-per-second callback, we can eliminate it entirely to conserve CPU when idle. The functionality removed includes: closing connections, circuits, and channels (ticket 25932); consensus voting (25937); flushing log callbacks (25951); honoring delayed SIGNEWNYM requests (25949); rescanning the consensus cache (25931); saving the state file to disk (25948); warning relay operators about unreachable ports (25952); and keeping track of Tor's uptime (26009).
Major bug fixes (directory authorities, security):
When directory authorities read a zero-byte bandwidth file, they would previously log a warning with the contents of an uninitialised buffer. They now log a warning about the empty file instead. Fixes bug 26007; bugfix on 0.2.2.1-alpha.
Major bug fixes (crash):
Avoid a rare assertion failure in the circuit build timeout code if we fail to allow any circuits to actually complete. Fixes bug 25733; bugfix on 0.2.2.2-alpha.
Major bug fixes (directory authority):
Avoid a crash when testing router reachability on a router that could have an ed25519 ID, but which does not. Fixes bug 25415; bugfix on 0.3.3.2-alpha.
Major bug fixes (onion service):
Correctly detect when onion services get disabled after HUP. Fixes bug 25761; bugfix on 0.3.2.1.
Major bug fixes (protover, voting):
Revise Rust implementation of protover to use a more memory- efficient voting algorithm and corresponding data structures, thus avoiding a potential (but small impact) DoS attack where specially crafted protocol strings would expand to several potential megabytes in memory. In the process, several portions of code were revised to be methods on new, custom types, rather than functions taking interchangeable types, thus increasing type safety of the module. Custom error types and handling were added as well, in order to facilitate better error dismissal/handling in outside crates and avoid mistakenly passing an internal error string to C over the FFI boundary. Many tests were added, and some previous differences between the C and Rust implementations have been remedied. Fixes bug 24031; bugfix on 0.3.3.1-alpha.
Major bug fixes (relay, denial of service):
Impose a limit on circuit cell queue size. The limit can be controlled by a consensus parameter. Fixes bug 25226; bugfix on 0.2.4.14-alpha.
Minor features (accounting):
When Tor becomes dormant, it now uses a scheduled event to wake up at the right time. Previously, we would use the per-second timer to check whether to wake up, but we no longer have any per-second timers enabled when the network is disabled. Closes ticket 26064.
Minor features (code quality):
Add optional spell-checking for the Tor codebase, using the "misspell" program. To use this feature, run "make check-typos". Closes ticket 25024.
Minor features (compatibility):
Tor now detects versions of OpenSSL 1.1.0 and later compiled with the no-deprecated option, and builds correctly with them. Closes tickets 19429, 19981, and 25353.
Avoid some compilation warnings with recent versions of LibreSSL. Closes ticket 26006.
Minor features (compression, zstd):
When running with zstd, Tor now considers using advanced functions that the zstd maintainers have labeled as potentially unstable. To prevent breakage, Tor will only use this functionality when the runtime version of the zstd library matches the version with which Tor was compiled. Closes ticket 25162.
Minor features (configuration):
The "DownloadSchedule" options have been renamed to end with "DownloadInitialDelay". The old names are still allowed, but will produce a warning. Comma-separated lists are still permitted for these options, but all values after the first are ignored (as they have been since 0.2.9). Closes ticket 23354.
Minor features (continuous integration):
Our .travis.yml configuration now includes support for testing the results of "make distcheck". (It's not uncommon for "make check" to pass but "make distcheck" to fail.) Closes ticket 25814.
Our Travis CI configuration now integrates with the Coveralls coverage analysis tool. Closes ticket 25818.
Minor features (control port):
Introduce GETINFO "current-time/{local,utc}" to return the local and UTC times respectively in ISO format. This helps a controller like Tor Browser detect a time-related error. Closes ticket 25511. Patch by Neel Chauhan.
Introduce new fields to the CIRC_BW event. There are two new fields in each of the read and written directions. The DELIVERED fields report the total valid data on the circuit, as measured by the payload sizes of verified and error-checked relay command cells. The OVERHEAD fields report the total unused bytes in each of these cells. Closes ticket 25903.
Minor features (directory authority):
Directory authorities now open their key-pinning files as O_SYNC, to limit their chances of accidentally writing partial lines. Closes ticket 23909.
Minor features (directory authority, forward compatibility):
Make the lines of the measured bandwidth file able to contain their entries in any order. Previously, the node_id entry needed to come first. Closes ticket 26004.
Minor features (entry guards):
Introduce a new torrc option NumPrimaryGuards for controlling the number of primary guards. Closes ticket 25843.
Minor features (geoip):
Update geoip and geoip6 to the May 1 2018 Maxmind GeoLite2 Country database. Closes ticket 26104.
Minor features (performance):
Avoid a needless call to malloc() when processing an incoming relay cell. Closes ticket 24914.
Make our timing-wheel code run a tiny bit faster on 32-bit platforms, by preferring 32-bit math to 64-bit. Closes ticket 24688.
Avoid a needless malloc()/free() pair every time we handle an ntor handshake. Closes ticket 25150.
Minor features (testing):
Add a unit test for voting_schedule_get_start_of_next_interval(). Closes ticket 26014, and helps make unit test coverage more deterministic.
A new unittests module specifically for testing the functions in the (new-ish) bridges.c module has been created with new unittests, raising the code coverage percentages. Closes 25425.
We now have improved testing for addressmap_get_virtual_address() function. This should improve our test coverage, and make our test coverage more deterministic. Closes ticket 25993.
Minor features (timekeeping, circuit scheduling):
When keeping track of how busy each circuit have been recently on a given connection, use coarse-grained monotonic timers rather than gettimeofday(). This change should marginally increase accuracy and performance. Implements part of ticket 25927.
Minor bug fixes (bandwidth management):
Consider ourselves "low on write bandwidth" if we have exhausted our write bandwidth some time in the last second. This was the documented behavior before, but the actual behavior was to change this value every TokenBucketRefillInterval. Fixes bug 25828; bugfix on 0.2.3.5-alpha.
Minor bug fixes (C correctness):
Add a missing lock acquisition in the shutdown code of the control subsystem. Fixes bug 25675; bugfix on 0.2.7.3-rc. Found by Coverity; this is CID 1433643.
Minor bug fixes (circuit path selection):
Don't count path selection failures as circuit build failures. This change should eliminate cases where Tor blames its guard or the network for situations like insufficient microdescriptors and/or overly restrictive torrc settings. Fixes bug 25705; bugfix on 0.3.3.1-alpha.
Minor bug fixes (client):
Don't consider Tor running as a client if the ControlPort is open, but no actual client ports are open. Fixes bug 26062; bugfix on 0.2.9.4-alpha.
Minor bug fixes (code style):
Fixed multiple includes of transports.h in src/or/connection.c Fixes bug 25261; bugfix on 0.2.5.1-alpha.
Remove the unused variable n_possible from the function channel_get_for_extend(). Fixes bug 25645; bugfix on 0.2.4.4-alpha
Minor bug fixes (control interface):
Respond with more human-readable error messages to GETINFO exit- policy/* requests. Also, let controller know if an error is transient (response code 551) or not (response code 552). Fixes bug 25852; bugfix on 0.2.8.1-alpha.
Minor bug fixes (controller):
Make CIRC_BW event reflect the total of all data sent on a circuit, including padding and dropped cells. Also fix a mis- counting bug when STREAM_BW events were enabled. Fixes bug 25400; bugfix on 0.2.5.2-alpha.
Minor bug fixes (correctness, client):
Upon receiving a malformed connected cell, stop processing the cell immediately. Previously we would mark the connection for close, but continue processing the cell as if the connection were open. Fixes bug 26072; bugfix on 0.2.4.7-alpha.
Minor bug fixes (directory client):
When unverified-consensus is verified, rename it to cached- consenus. Fixes bug 4187; bugfix on 0.2.0.3-alpha.
Fixed launching a certificate fetch always during the scheduled periodic consensus fetch by fetching only in those cases when consensus are waiting for certs. Fixes bug 24740; bugfix on 0.2.9.1-alpha.
Minor bug fixes (documentation):
Stop saying in the manual that clients cache ipv4 dns answers from exit relays. We haven't used them since 0.2.6.3-alpha, and in ticket 24050 we stopped even caching them as of 0.3.2.6-alpha, but we forgot to say so in the man page. Fixes bug 26052; bugfix on 0.3.2.6-alpha.
Minor bug fixes (error reporting):
Improve tolerance for directory authorities with skewed clocks. Previously, an authority with a clock more than 60 seconds ahead could cause a client with a correct clock to warn that the client's clock was behind. Now the clocks of a majority of directory authorities have to be ahead of the client before this warning will occur. Fixes bug 25756; bugfix on 0.2.2.25-alpha.
Minor bug fixes (Linux seccomp2 sandbox):
Allow the nanosleep() system call, which glibc uses to implement sleep() and usleep(). Fixes bug 24969; bugfix on 0.2.5.1-alpha.
Minor bug fixes (onion service):
Fix a memory leak when a v3 onion service is configured and gets a SIGHUP signal. Fixes bug 25901; bugfix on 0.3.2.1-alpha.
When parsing the descriptor signature, look for the token plus an extra white-space at the end. This is more correct but also will allow us to support new fields that might start with "signature". Fixes bug 26069; bugfix on 0.3.0.1-alpha.
Minor bug fixes (path selection):
Only select relays when they have the descriptors we prefer to use for them. This change fixes a bug where we could select a relay because it had _some_ descriptor, but reject it later with a nonfatal assertion error because it didn't have the exact one we wanted. Fixes bugs 25691 and 25692; bugfix on 0.3.3.4-alpha.
Minor bug fixes (portability):
Do not align mmap length, as it is not required by POSIX, and the getpagesize function is deprecated. Fixes bug 25399; bugfix on 0.1.1.23.
Minor bug fixes (portability, FreeBSD):
In have_enough_mem_for_dircache(), the variable DIRCACHE_MIN_MEM_MB does not stringify on FreeBSD, so we switch to tor_asprintf(). Fixes bug 20887; bugfix on 0.2.8.1-alpha. Patch by Neel Chauhan.
Minor bug fixes (relay statistics):
When a relay is collecting internal statistics about how many create cell requests it has seen of each type, accurately count the requests from relays that temporarily fall out of the consensus. (To be extra conservative, we were already ignoring requests from clients in our counts, and we continue ignoring them here.) Fixes bug 24910; bugfix on 0.2.4.17-rc.
Minor bug fixes (relay, crash):
Avoid a crash when running with DirPort set but ORPort tuned off. Fixes a case of bug 23693; bugfix on 0.3.1.1-alpha.
Minor bug fixes (restart-in-process):
When shutting down, Tor now clears all the flags in the control.c module. This should prevent a bug where authentication cookies are not generated on restart. Fixes bug 25512; bugfix on 0.3.3.1-alpha.
Minor bug fixes (testing):
When testing workqueue event-cancellation, make sure that we actually cancel an event, and that cancel each event with equal probability. (It was previously possible, though extremely unlikely, for our event-canceling test not to cancel any events.) Fixes bug 26008; bugfix on 0.2.6.3-alpha.
Repeat part of the test in test_client_pick_intro() a number of times, to give it consistent coverage. Fixes bug 25996; bugfix on 0.3.2.1-alpha.
Remove randomness from the hs_common/responsible_hsdirs test, so that it always takes the same path through the function it tests. Fixes bug 25997; bugfix on 0.3.2.1-alpha.
Change the behavior of the "channel/outbound" test so that it never causes a 10-second rollover for the EWMA circuitmux code. Previously, this behavior would happen randomly, and result in fluctuating test coverage. Fixes bug 25994; bugfix on 0.3.3.1-alpha.
Use X509_new() to allocate certificates that will be freed later with X509_free(). Previously, some parts of the unit tests had used tor_malloc_zero(), which is incorrect, and which caused test failures on Windows when they were built with extra hardening. Fixes bugs 25943 and 25944; bugfix on 0.2.8.1-alpha. Patch by Marcin Cieślak.
While running the circuit_timeout test, fix the PRNG to a deterministic AES stream, so that the test coverage from this test will itself be deterministic. Fixes bug 25995; bugfix on 0.2.2.2-alpha.
Minor bug fixes (vanguards):
Allow the last hop in a vanguard circuit to be the same as our first, to prevent the adversary from influencing guard node choice by choice of last hop. Also prevent the creation of A - B - A paths, or A - A paths, which are forbidden by relays. Fixes bug 25870; bugfix on 0.3.3.1-alpha.
Code simplification and refactoring:
Remove duplicate code in parse_{c,s}method_line and bootstrap their functionalities into a single function. Fixes bug 6236; bugfix on 0.2.3.6-alpha.
We remove the PortForwsrding and PortForwardingHelper options, related functions, and the port_forwarding tests. These options were used by the now-deprecated Vidalia to help ordinary users become Tor relays or bridges. Closes ticket 25409. Patch by Neel Chauhan.
In order to make the OR and dir checking function in router.c less confusing we renamed some functions and consider_testing_reachability() has been split into router_should_check_reachability() and router_do_reachability_checks(). Also we improved the documentation in some functions. Closes ticket 18918.
Initial work to isolate Libevent usage to a handful of modules in our codebase, to simplify our call structure, and so that we can more easily change event loops in the future if needed. Closes ticket 23750.
Introduce a function to call getsockname() and return tor_addr_t, to save a little complexity throughout the codebase. Closes ticket 18105.
Make hsdir_index in node_t a hsdir_index_t rather than a pointer as hsdir_index is always present. Also, we move hsdir_index_t into or.h. Closes ticket 23094. Patch by Neel Chauhan.
Merge functions used for describing nodes and suppress the functions that do not allocate memory for the output buffer string. NODE_DESC_BUF_LEN constant and format_node_description() function cannot be used externally from router.c module anymore. Closes ticket 25432. Patch by valentecaio.
Our main loop has been simplified so that all important operations happen inside events. Previously, some operations had to happen outside the event loop, to prevent infinite sequences of event activations. Closes ticket 25374.
Put a SHA1 public key digest in hs_service_intro_point_t, and use it in register_intro_circ() and service_intro_point_new(). This prevents the digest from being re-calculated each time. Closes ticket 23107. Patch by Neel Chauhan.
Refactor token-bucket implementations to use a common backend. Closes ticket 25766.
Remove extern declaration of stats_n_seconds_working variable from main, protecting its accesses with get_uptime() and reset_uptime() functions. Closes ticket 25081, patch by “valentecaio”.
Remove our previous logic for "cached gettimeofday()" -- our coarse monotonic timers are fast enough for this purpose, and far less error-prone. Implements part of ticket 25927.
Remove the return value for fascist_firewall_choose_address_base(), and sister functions such as fascist_firewall_choose_address_node() and fascist_firewall_choose_address_rs(). Also, while we're here, initialize the ap argument as leaving it uninitialized can pose a security hazard. Closes ticket 24734. Patch by Neel Chauhan.
Rename two fields of connection_t struct. timestamp_lastwritten is renamed to timestamp_last_write_allowed and timestamp_lastread is renamed to timestamp_last_read_allowed. Closes ticket 24714, patch by "valentecaio".
Since Tor requires C99, remove our old workaround code for libc implementations where free(NULL) doesn't work. Closes ticket 24484.
Use our standard rate-limiting code to deal with excessive libevent failures, rather than the hand-rolled logic we had before. Closes ticket 26016.
We remove the return value of node_get_prim_orport() and node_get_prim_dirport(), and introduce node_get_prim_orport() in node_ipv6_or_preferred() and node_ipv6_dir_preferred() in order to check for a null address. Closes ticket 23873. Patch by Neel Chauhan.
We switch to should_record_bridge_info() in geoip_note_client_seen() and options_need_geoip_info() instead of accessing the configuration values directly. Fixes bug 25290; bugfix on 0.2.1.6-alpha. Patch by Neel Chauhan.
Deprecated features:
As we are not recommending 0.2.5 anymore, we require relays that once had an ed25519 key associated with their RSA key to always have that key, instead of allowing them to drop back to a version that didn't support ed25519. This means they need to use a new RSA key if the want to downgrade to an older version of tor without ed25519. Closes ticket 20522.
Documentation:
Correct an IPv6 error in the documentation for ExitPolicy. Closes ticket 25857. Patch from "CTassisF".
Removed features:
Directory authorities will no longer support voting according to any consensus method before consensus method 25. This keeps authorities compatible with all authorities running 0.2.9.8 and later, and does not break any clients or relays. Implements ticket 24378 and proposal 290.
The PortForwarding and PortForwardingHelper features have been removed. The reasoning is, given that implementations of NAT traversal protocols within common consumer grade routers are frequently buggy, and that the target audience for a NAT punching feature is a perhaps less-technically-inclined relay operator, when the helper fails to setup traversal the problems are usually deep, ugly, and very router specific, making them horrendously impossible for technical support to reliable assist with, and thus resulting in frustration all around. Unfortunately, relay operators who would like to run relays behind NATs will need to become more familiar with the port forwarding configurations on their local router. Closes 25409.
The TestingEnableTbEmptyEvent option has been removed. It was used in testing simulations to measure how often connection buckets were emptied, in order to improve our scheduling, but it has not been actively used in years. Closes ticket 25760.
The old "round-robin" circuit multiplexer (circuitmux) implementation has been removed, along with a fairly large set of code that existed to support it. It has not been the default circuitmux since we introduced the "EWMA" circuitmux in 0.2.4.x, but it still required an unreasonable amount of memory and CPU. Closes ticket 25268.

New in Tor 0.3.3.5 RC (Apr 16, 2018)

Major bug fixes (security, protover, voting):
Revise Rust implementation of protover to use a more memory- efficient voting algorithm and corresponding data structures, thus avoiding a potential memory-based DoS attack where specially crafted protocol strings would expand to fill available memory. Fixes bug 24031; bugfix on 0.3.3.1-alpha.
Major bug fixes (performance, load balancing):
Directory authorities no longer vote in favor of the Guard flag for relays without directory support. Starting in Tor 0.3.0.1-alpha, clients have been avoiding using such relays in the Guard position, leading to increasingly broken load balancing for the 5%-or-so of Guards that don't advertise directory support. Fixes bug 22310; bugfix on 0.3.0.6.
Minor feature (continuous integration):
Update the Travis CI configuration to use the stable Rust channel, now that we have decided to require that. Closes ticket 25714.
Minor features (config options):
Change the way the default value for MaxMemInQueues is calculated. We now use 40% of the hardware RAM if the system has 8 GB RAM or more. Otherwise we use the former value of 75%. Closes ticket 24782.
Minor features (geoip):
Update geoip and geoip6 to the April 3 2018 Maxmind GeoLite2 Country database. Closes ticket 25718.
Minor bug fixes (client):
When using a listed relay as a bridge, and also using microdescriptors, and considering that relay as a non-bridge in a circuit, treat its microdescriptor as a valid source of information about that relay. This change should prevent a non- fatal assertion error. Fixes bug 25691; bugfix on 0.3.3.4-alpha.
Minor bug fixes (controller):
Restore the correct operation of the RESOLVE command, which had been broken since we added the ability to enable/disable DNS on specific listener ports. Fixes bug 25617; bugfix on 0.2.9.3-alpha.
Minor bug fixes (distribution, compilation, rust):
Build correctly when the rust dependencies submodule is loaded, but the TOR_RUST_DEPENDENCIES environment variable is not set. Fixes bug 25679; bugfix on 0.3.3.1-alpha.
Actually include all of our Rust source in our source distributions. (Previously, a few of the files were accidentally omitted.) Fixes bug 25732; bugfix on 0.3.3.2-alpha.
Minor bug fixes (documentation):
Document that the PerConnBW{Rate,Burst} options will fall back to their corresponding consensus parameters only if those parameters are set. Previously we had claimed that these values would always be set in the consensus. Fixes bug 25296; bugfix on 0.2.2.7-alpha.
Revert a misformatting issue in the ExitPolicy documentation. Fixes bug 25582; bugfix on 0.3.3.1-alpha.
Minor bug fixes (exit node DNS retries):
Re-attempt timed-out DNS queries 3 times before failure, since our timeout is 5 seconds for them, but clients wait 10-15. Also allow slightly more timeouts per resolver when an exit has multiple resolvers configured. Fixes bug 21394; bugfix on 0.3.1.9.
Minor bug fixes (onion services):
Re-instate counting the client HSDir fetch circuits against the MaxClientCircuitsPending rate limit. Fixes bug 24989; bugfix on 0.3.3.1-alpha.
Remove underscores from the _HSLayer{2,3}Nodes options. This expert-user configuration can now be enabled as HSLayer{2,3}Nodes. Fixes bug 25581; bugfix on 0.3.3.1-alpha
Code simplification and refactoring:
Move the list of default directory authorities to its own file. Closes ticket 24854. Patch by "beastr0".
Documentation (manpage, denial of service):
Provide more detail about the denial-of-service options, by listing each mitigation and explaining how they relate. Closes ticket 25248.

New in Tor 0.3.3.4 Alpha (Mar 30, 2018)

Tor 0.3.3.4-alpha includes various bug fixes for issues found during the alpha testing of earlier releases in its series. We are approaching a stable 0.3.3.4-alpha release: more testing is welcome!
New system requirements:
When built with Rust, Tor now depends on version 0.2.39 of thelibc crate. Closes tickets 25310 and 25664.
Major bug fixes (relay, connection):
If we have failed to connect to a relay and received a connectionrefused, timeout, or similar error (at the TCP level), do not trythat same address/port again for 60 seconds after the failure hasoccurred. Fixes bug 24767; bugfix on 0.0.6.
Minor features (geoip):
Update geoip and geoip6 to the March 8 2018 Maxmind GeoLite2Country database. Closes ticket 25469.
Minor features (log messages):
Improve log message in the out-of-memory handler to includeinformation about memory usage from the different compressionbackends. Closes ticket 25372.
Minor features (sandbox):
Explicitly permit the poll() system call when the Linuxseccomp2-based sandbox is enabled: apparently, some versions oflibc use poll() when calling getpwnam(). Closes ticket 25313.
Minor bug fixes (C correctness):
Fix a very unlikely (impossible, we believe) null pointerdereference. Fixes bug 25629; bugfix on 0.2.9.15. Found byCoverity; this is CID 1430932.
Minor bug fixes (channel, client):
Better identify client connection when reporting to the geoipclient cache. Fixes bug 24904; bugfix on 0.3.1.7.
Minor bug fixes (compilation):
Fix a C99 compliance issue in our configuration script that causedcompilation issues when compiling Tor with certain versions ofxtools. Fixes bug 25474; bugfix on 0.3.2.5-alpha.
Minor bug fixes (controller, reliability):
Avoid a (nonfatal) assertion failure when extending a one-hopcircuit from the controller to become a multihop circuit. Fixesbug 24903; bugfix on 0.2.5.2-alpha.
Minor bug fixes (networking):
Tor will no longer reject IPv6 address strings from TorBrowserwhen they are passed as hostnames in SOCKS5 requests. Fixes bug25036, bugfix on Tor 0.3.1.2.
string_is_valid_hostname() will not consider IP strings to bevalid hostnames. Fixes bug 25055; bugfix on Tor 0.2.5.5.
Minor bug fixes (onion service v3):
Avoid an assertion failure when the next the next onion servicedescriptor rotation type is out of sync with the consensus'svalid-after time. Instead, log a warning message with extrainformation, so we can better hunt down the cause of thisassertion. Fixes bug 25306; bugfix on 0.3.2.1-alpha.
Minor bug fixes (testing):
Avoid intermittent test failures due to a test that had relied ononion service introduction point creation finishing within 5seconds of real clock time. Fixes bug 25450; bugfixon 0.3.1.3-alpha.
Rust crates are now automatically detected and tested. Previously,some crates were not tested by `make test-rust` due to a staticstring in the `src/test/test_rust.sh` script specifying whichcrates to test. Fixes bug 25560; bugfix on 0.3.3.3-alpha.
Minor bug fixes (testing, benchmarks):
Fix a crash when running benchmark tests on win32 systems. Thecrash was due to a mutex that wasn't initialized before loggingand options were initialized. Fixes bug 25479; bugfixon 0.3.3.3-alpha.
Minor bug fixes (warnings, ipv6):
Avoid a bug warning that could occur when trying to connect to arelay over IPv6. This warning would occur on a Tor instance thatdownloads router descriptors, but prefers to use microdescriptors.Fixes bug 25213; bugfix on 0.3.3.1-alpha.
Code simplification and refactoring:
Remove the old (deterministic) directory retry logic entirely:We've used exponential backoff exclusively for some time. Closesticket 23814.
Documentation:
Improved the documentation of AccountingStart parameter. Closesticket 23635.
Update the documentation for "Log" to include the current list oflogging domains. Closes ticket 25378.

New in Tor 0.3.2.10 (Mar 4, 2018)

Major bugfixes (denial-of-service, directory authority, backport from 0.3.3.3-alpha):
Fix a protocol-list handling bug that could be used to remotely crash directory authorities with a null-pointer exception. Fixes bug 25074; bugfix on 0.2.9.4-alpha. Also tracked as TROVE-2018-001 and CVE-2018-0490.
Major bugfixes (scheduler, KIST, denial-of-service, backport from 0.3.3.2-alpha):
Avoid adding the same channel twice in the KIST scheduler pending list, which could lead to remote denial-of-service use-after-free attacks against relays. Fixes bug 24700; bugfix on 0.3.2.1-alpha.
Major features (denial-of-service mitigation, backport from 0.3.3.2-alpha):
Give relays some defenses against the recent network overload. We start with three defenses (default parameters in parentheses). First: if a single client address makes too many concurrent connections (>100), hang up on further connections. Second: if a single client address makes circuits too quickly (more than 3 per second, with an allowed burst of 90) while also having too many connections open (3), refuse new create cells for the next while (1-2 hours). Third: if a client asks to establish a rendezvous point to you directly, ignore the request. These defenses can be manually controlled by new torrc options, but relays will also take guidance from consensus parameters, so there's no need to configure anything manually. Implements ticket 24902.
Major bugfixes (onion services, retry behavior, backport from 0.3.3.1-alpha):
Fix an "off by 2" error in counting rendezvous failures on the onion service side. While we thought we would stop the rendezvous attempt after one failed circuit, we were actually making three circuit attempts before giving up. Now switch to a default of 2, and allow the consensus parameter "hs_service_max_rdv_failures" to override. Fixes bug 24895; bugfix on 0.0.6.
New-style (v3) onion services now obey the "max rendezvous circuit attempts" logic. Previously they would make as many rendezvous circuit attempts as they could fit in the MAX_REND_TIMEOUT second window before giving up. Fixes bug 24894; bugfix on 0.3.2.1-alpha.
Major bugfixes (protocol versions, backport from 0.3.3.2-alpha):
Add Link protocol version 5 to the supported protocols list. Fixes bug 25070; bugfix on 0.3.1.1-alpha.
Major bugfixes (relay, backport from 0.3.3.1-alpha):
Fix a set of false positives where relays would consider connections to other relays as being client-only connections (and thus e.g. deserving different link padding schemes) if those relays fell out of the consensus briefly. Now we look only at the initial handshake and whether the connection authenticated as a relay. Fixes bug 24898; bugfix on 0.3.1.1-alpha.
Major bugfixes (scheduler, consensus, backport from 0.3.3.2-alpha):
The scheduler subsystem was failing to promptly notice changes in consensus parameters, making it harder to switch schedulers network-wide. Fixes bug 24975; bugfix on 0.3.2.1-alpha.
Minor features (denial-of-service avoidance, backport from 0.3.3.2-alpha):
Make our OOM handler aware of the geoip client history cache so it doesn't fill up the memory. This check is important for IPv6 and our DoS mitigation subsystem. Closes ticket 25122.
Minor features (compatibility, OpenSSL, backport from 0.3.3.3-alpha):
Tor will now support TLS1.3 once OpenSSL 1.1.1 is released. Previous versions of Tor would not have worked with OpenSSL 1.1.1, since they neither disabled TLS 1.3 nor enabled any of the ciphersuites it requires. Now we enable the TLS 1.3 ciphersuites. Closes ticket 24978.
Minor features (geoip):
Update geoip and geoip6 to the February 7 2018 Maxmind GeoLite2 Country database.
Minor features (logging, diagnostic, backport from 0.3.3.2-alpha):
When logging a failure to check a hidden service's certificate, also log what the problem with the certificate was. Diagnostic for ticket 24972.
Minor bugfix (channel connection, backport from 0.3.3.2-alpha):
Use the actual observed address of an incoming relay connection, not the canonical address of the relay from its descriptor, when making decisions about how to handle the incoming connection. Fixes bug 24952; bugfix on 0.2.4.11-alpha. Patch by "ffmancera".
Minor bugfixes (denial-of-service, backport from 0.3.3.3-alpha):
Fix a possible crash on malformed consensus. If a consensus had contained an unparseable protocol line, it could have made clients and relays crash with a null-pointer exception. To exploit this issue, however, an attacker would need to be able to subvert the directory authority system. Fixes bug 25251; bugfix on 0.2.9.4-alpha. Also tracked as TROVE-2018-004.
Minor bugfix (directory authority, backport from 0.3.3.2-alpha):
Directory authorities, when refusing a descriptor from a rejected relay, now explicitly tell the relay (in its logs) to set a valid ContactInfo address and contact the bad-relays@ mailing list. Fixes bug 25170; bugfix on 0.2.9.1.
Minor bugfixes (build, rust, backport from 0.3.3.1-alpha):
When building with Rust on OSX, link against libresolv, to work around the issue at https://github.com/rust-lang/rust/issues/46797. Fixes bug 24652; bugfix on 0.3.1.1-alpha.
Minor bugfixes (onion services, backport from 0.3.3.2-alpha):
Remove a BUG() statement when a client fetches an onion descriptor that has a lower revision counter than the one in its cache. This can happen in normal circumstances due to HSDir desync. Fixes bug 24976; bugfix on 0.3.2.1-alpha.
Minor bugfixes (logging, backport from 0.3.3.2-alpha):
Don't treat inability to store a cached consensus object as a bug: it can happen normally when we are out of disk space. Fixes bug 24859; bugfix on 0.3.1.1-alpha.
Minor bugfixes (performance, fragile-hardening, backport from 0.3.3.1-alpha):
Improve the performance of our consensus-diff application code when Tor is built with the --enable-fragile-hardening option set. Fixes bug 24826; bugfix on 0.3.1.1-alpha.
Minor bugfixes (OSX, backport from 0.3.3.1-alpha):
Don't exit the Tor process if setrlimit() fails to change the file limit (which can happen sometimes on some versions of OSX). Fixes bug 21074; bugfix on 0.0.9pre5.
Minor bugfixes (spec conformance, backport from 0.3.3.3-alpha):
Forbid "-0" as a protocol version. Fixes part of bug 25249; bugfix on 0.2.9.4-alpha.
Forbid UINT32_MAX as a protocol version. Fixes part of bug 25249; bugfix on 0.2.9.4-alpha.
Minor bugfixes (testing, backport from 0.3.3.1-alpha):
Fix a memory leak in the scheduler/loop_kist unit test. Fixes bug 25005; bugfix on 0.3.2.7-rc.
Minor bugfixes (v3 onion services, backport from 0.3.3.2-alpha):
Look at the "HSRend" protocol version, not the "HSDir" protocol version, when deciding whether a consensus entry can support the v3 onion service protocol as a rendezvous point. Fixes bug 25105; bugfix on 0.3.2.1-alpha.
Code simplification and refactoring (backport from 0.3.3.3-alpha):
Update the "rust dependencies" submodule to be a project-level repository, rather than a user repository. Closes ticket 25323.
Documentation (backport from 0.3.3.1-alpha):
Document that operators who run more than one relay or bridge are expected to set MyFamily and ContactInfo correctly. Closes ticket 24526.

New in Tor 0.3.3.3 Alpha (Mar 4, 2018)

Major bugfixes (denial-of-service, directory authority):
Fix a protocol-list handling bug that could be used to remotely crash directory authorities with a null-pointer exception. Fixes bug 25074; bugfix on 0.2.9.4-alpha. Also tracked as TROVE-2018-001 and CVE-2018-0490.
Minor features (compatibility, OpenSSL):
Tor will now support TLS1.3 once OpenSSL 1.1.1 is released. Previous versions of Tor would not have worked with OpenSSL 1.1.1, since they neither disabled TLS 1.3 nor enabled any of the ciphersuites it requires. Now we enable the TLS 1.3 ciphersuites. Closes ticket 24978.
Minor features (logging):
Clarify the log messages produced when getrandom() or a related entropy-generation mechanism gives an error. Closes ticket 25120.
Minor features (testing):
Add a "make test-rust" target to run the rust tests only. Closes ticket 25071.
Minor bugfixes (denial-of-service):
Fix a possible crash on malformed consensus. If a consensus had contained an unparseable protocol line, it could have made clients and relays crash with a null-pointer exception. To exploit this issue, however, an attacker would need to be able to subvert the directory authority system. Fixes bug 25251; bugfix on 0.2.9.4-alpha. Also tracked as TROVE-2018-004.
Minor bugfixes (DoS mitigation):
Add extra safety checks when refilling the circuit creation bucket to ensure we never set a value above the allowed maximum burst. Fixes bug 25202; bugfix on 0.3.3.2-alpha.
When a new consensus arrives, don't update our DoS-mitigation parameters if we aren't a public relay. Fixes bug 25223; bugfix on 0.3.3.2-alpha.
Minor bugfixes (man page, SocksPort):
Remove dead code from the old "SocksSocket" option, and rename SocksSocketsGroupWritable to UnixSocksGroupWritable. The old option still works, but is deprecated. Fixes bug 24343; bugfix on 0.2.6.3.
Minor bugfixes (performance):
Reduce the number of circuits that will be opened at once during the circuit build timeout phase. This is done by increasing the idle timeout to 3 minutes, and lowering the maximum number of concurrent learning circuits to 10. Fixes bug 24769; bugfix on 0.3.1.1-alpha.
Minor bugfixes (spec conformance):
Forbid "-0" as a protocol version. Fixes part of bug 25249; bugfix on 0.2.9.4-alpha.
Forbid UINT32_MAX as a protocol version. Fixes part of bug 25249; bugfix on 0.2.9.4-alpha.
Minor bugfixes (spec conformance, rust):
Resolve a denial-of-service issue caused by an infinite loop in the rust protover code. Fixes bug 25250, bugfix on 0.3.3.1-alpha. Also tracked as TROVE-2018-003.
Code simplification and refactoring:
Update the "rust dependencies" submodule to be a project-level repository, rather than a user repository. Closes ticket 25323.

New in Tor 0.3.3.2 Alpha (Feb 10, 2018)

Tor 0.3.3.2-alpha is the second alpha in the 0.3.3.x series. It introduces a mechanism to handle the high loads that many relay operators have been reporting recently. It also fixes several bugs in older releases. If this new code proves reliable, we plan to backport it to older supported release series.
Major features (denial-of-service mitigation):
Give relays some defenses against the recent network overload. We start with three defenses (default parameters in parentheses). First: if a single client address makes too many concurrent connections (>100), hang up on further connections. Second: if a single client address makes circuits too quickly (more than 3 per second, with an allowed burst of 90) while also having too many connections open (3), refuse new create cells for the next while (1-2 hours). Third: if a client asks to establish a rendezvous point to you directly, ignore the request. These defenses can be manually controlled by new torrc options, but relays will also take guidance from consensus parameters, so there's no need to configure anything manually. Implements ticket 24902.
Major bug fixes (netflow padding):
Stop adding unneeded channel padding right after we finish flushing to a connection that has been trying to flush for many seconds. Instead, treat all partial or complete flushes as activity on the channel, which will defer the time until we need to add padding. This fix should resolve confusing and scary log messages like "Channel padding timeout scheduled 221453ms in the past." Fixes bug 22212; bugfix on 0.3.1.1-alpha.
Major bug fixes (protocol versions):
Add Link protocol version 5 to the supported protocols list. Fixes bug 25070; bugfix on 0.3.1.1-alpha.
Major bug fixes (scheduler, consensus):
The scheduler subsystem was failing to promptly notice changes in consensus parameters, making it harder to switch schedulers network-wide. Fixes bug 24975; bugfix on 0.3.2.1-alpha.
Minor features (denial-of-service avoidance):
Make our OOM handler aware of the geoip client history cache so it doesn't fill up the memory. This check is important for IPv6 and our DoS mitigation subsystem. Closes ticket 25122.
Minor features (directory authority):
When directory authorities are unable to add signatures to a pending consensus, log the reason why. Closes ticket 24849.
Minor features (geoip):
Update geoip and geoip6 to the February 7 2018 Maxmind GeoLite2 Country database.
Minor features (logging, diagnostic):
When logging a failure to create an onion service's descriptor, also log what the problem with the descriptor was. Diagnostic for ticket 24972.
Minor bugfix (channel connection):
Use the actual observed address of an incoming relay connection, not the canonical address of the relay from its descriptor, when making decisions about how to handle the incoming connection. Fixes bug 24952; bugfix on 0.2.4.11-alpha. Patch by "ffmancera".
Minor bugfix (directory authority):
Directory authorities, when refusing a descriptor from a rejected relay, now explicitly tell the relay (in its logs) to set a valid ContactInfo address and contact the bad-relays@ mailing list. Fixes bug 25170; bugfix on 0.2.9.1.
Minor bug fixes (all versions of Tor):
Use the "misspell" tool to detect and fix typos throughout the source code. Fixes bug 23650; bugfix on various versions of Tor. Patch from Deepesh Pathak.
Minor bug fixes (circuit, cannibalization):
Don't cannibalize preemptively-built circuits if we no longer recognize their first hop. This situation can happen if our Guard relay went off the consensus after the circuit was created. Fixes bug 24469; bugfix on 0.0.6.
Minor bug fixes (correctness):
Remove a nonworking, unnecessary check to see whether a circuit hop's identity digest was set when the circuit failed. Fixes bug 24927; bugfix on 0.2.4.4-alpha.
Minor bug fixes (logging):
Don't treat inability to store a cached consensus object as a bug: it can happen normally when we are out of disk space. Fixes bug 24859; bugfix on 0.3.1.1-alpha.
Fix a (mostly harmless) race condition when invoking LOG_PROTOCOL_WARN message from a subthread while the torrc options are changing. Fixes bug 23954; bugfix on 0.1.1.9-alpha.
Minor bug fixes (onion services):
Remove a BUG() statement when a client fetches an onion descriptor that has a lower revision counter than the one in its cache. This can happen in normal circumstances due to HSDir desync. Fixes bug 24976; bugfix on 0.3.2.1-alpha.
If we are configured to offer a single onion service, don't log long-term established one hop rendezvous points in the heartbeat. Fixes bug 25116; bugfix on 0.2.9.6-rc.
Minor bug fixes (performance):
Avoid calling protocol_list_supports_protocol() from inside tight loops when running with cached routerinfo_t objects. Instead, summarize the relevant protocols as flags in the routerinfo_t, as we do for routerstatus_t objects. This change simplifies our code a little, and saves a large amount of short-term memory allocation operations. Fixes bug 25008; bugfix on 0.2.9.4-alpha.
Minor bug fixes (Rust FFI):
Fix a minor memory leak which would happen whenever the C code would call the Rust implementation of protover_get_supported_protocols(). This was due to the C version returning a static string, whereas the Rust version newly allocated a CString to pass accross the FFI boundary. Consequently, the C code was not expecting to need to free() what it was given. Fixes bug 25127; bugfix on 0.3.2.1-alpha.
Minor bug fixes (scheduler, KIST):
Avoid adding the same channel twice in the KIST scheduler pending list, which would waste CPU cycles. Fixes bug 24700; bugfix on 0.3.2.1-alpha.
Minor bug fixes (unit test, monotonic time):
Increase a constant (1msec to 10msec) in the monotonic time test that makes sure the nsec/usec/msec times read are synchronized. This change was needed to accommodate slow systems like armel or when the clock_gettime() is not a VDSO on the running kernel. Fixes bug 25113; bugfix on 0.2.9.1.
Minor bug fixes (v3 onion services):
Look at the "HSRend" protocol version, not the "HSDir" protocol version, when deciding whether a consensus entry can support the v3 onion service protocol as a rendezvous point. Fixes bug 25105; bugfix on 0.3.2.1-alpha.
Code simplification and refactoring:
Remove the unused nodelist_recompute_all_hsdir_indices(). Closes ticket 25108.
Remove a series of counters used to track circuit extend attempts and connection status but that in reality we aren't using for anything other than stats logged by a SIGUSR1 signal. Closes ticket 25163.
Documentation (man page):
The HiddenServiceVersion torrc option accepts only one number: either version 2 or 3. Closes ticket 25026; bugfix on 0.3.2.2-alpha.

New in Tor 0.3.2.9 (Jan 10, 2018)

DIRECTORY AUTHORITY CHANGES:
Add "Bastet" as a ninth directory authority to the default list. Closes ticket 23910.
The directory authority "Longclaw" has changed its IP address. Closes ticket 23592.
Remove longclaw's IPv6 address, as it will soon change. Authority IPv6 addresses were originally added in 0.2.8.1-alpha. This leaves 3/8 directory authorities with IPv6 addresses, but there are also 52 fallback directory mirrors with IPv6 addresses. Resolves 19760.
Add an IPv6 address for the "bastet" directory authority. Closes ticket 24394.
MAJOR FEATURES (NEXT-GENERATION ONION SERVICES):
Tor now supports the next-generation onion services protocol for clients and services! As part of this release, the core of proposal 224 has been implemented and is available for experimentation and testing by our users.
This newer version of onion services ("v3") features many improvements over the legacy system, including:
a) Better crypto (replaced SHA1/DH/RSA1024 with SHA3/ed25519/curve25519)
b) Improved directory protocol, leaking much less information to directory servers.
c) Improved directory protocol, with smaller surface for targeted attacks.
d) Better onion address security against impersonation.
e) More extensible introduction/rendezvous protocol.
f) A cleaner and more modular codebase.
You can identify a next-generation onion address by its length: they are 56 characters long, as in "4acth47i6kxnvkewtm6q7ib2s3ufpo5sqbsnzjpbi7utijcltosqemad.onion".
In the future, we will release more options and features for v3 onion services, but we first need a testing period, so that the current codebase matures and becomes more robust. Planned features include: offline keys, advanced client authorization, improved guard algorithms, and statistics. For full details, see proposal 224.
Legacy ("v2") onion services will still work for the foreseeable future, and will remain the default until this new codebase gets tested and hardened. Service operators who want to experiment with the new system can use the 'HiddenServiceVersion 3' torrc directive along with the regular onion service configuration options. For more information, see our blog post at "https://blog.torproject.org/fall-harvest". Enjoy!
MAJOR FEATURE (SCHEDULER, CHANNEL):
Tor now uses new schedulers to decide which circuits should deliver cells first, in order to improve congestion at relays. The first type is called "KIST" ("Kernel Informed Socket Transport"), and is only available on Linux-like systems: it uses feedback from the kernel to prevent the kernel's TCP buffers from growing too full. The second new scheduler type is called "KISTLite": it behaves the same as KIST, but runs on systems without kernel support for inspecting TCP implementation details. The old scheduler is still available, under the name "Vanilla". To change the default scheduler preference order, use the new "Schedulers" option. (The default preference order is "KIST,KISTLite,Vanilla".)
Matt Traudt implemented KIST, based on research by Rob Jansen, John Geddes, Christ Wacek, Micah Sherr, and Paul Syverson. For more information, see the design paper at http://www.robgjansen.com/publications/kist-sec2014.pdf and the followup implementation paper at https://arxiv.org/abs/1709.01044. Closes ticket 12541. For more information, see our blog post at "https://blog.torproject.org/kist-and-tell".
MAJOR BUG FIXES (SECURITY, GENERAL):
Fix a denial of service bug where an attacker could use a malformed directory object to cause a Tor instance to pause while OpenSSL would try to read a passphrase from the terminal. (Tor instances run without a terminal, which is the case for most Tor packages, are not impacted.) Fixes bug 24246; bugfix on every version of Tor. Also tracked as TROVE-2017-011 and CVE-2017-8821. Found by OSS-Fuzz as testcase 6360145429790720.
MAJOR BUG FIXES (SECURITY, DIRECTORY AUTHORITY):
Fix a denial of service issue where an attacker could crash a directory authority using a malformed router descriptor. Fixes bug 24245; bugfix on 0.2.9.4-alpha. Also tracked as TROVE-2017-010 and CVE-2017-8820.
MAJOR BUG FIXES (SECURITY, ONION SERVICE V2):
Fix a use-after-free error that could crash v2 Tor onion services when they failed to open circuits while expiring introduction points. Fixes bug 24313; bugfix on 0.2.7.2-alpha. This issue is also tracked as TROVE-2017-013 and CVE-2017-8823.
When checking for replays in the INTRODUCE1 cell data for a (legacy) onion service, correctly detect replays in the RSA- encrypted part of the cell. We were previously checking for replays on the entire cell, but those can be circumvented due to the malleability of Tor's legacy hybrid encryption. This fix helps prevent a traffic confirmation attack. Fixes bug 24244; bugfix on 0.2.4.1-alpha. This issue is also tracked as TROVE-2017-009 and CVE-2017-8819.
MAJOR BUG FIXES (SECURITY, RELAY):
When running as a relay, make sure that we never build a path through ourselves, even in the case where we have somehow lost the version of our descriptor appearing in the consensus. Fixes part of bug 21534; bugfix on 0.2.0.1-alpha. This issue is also tracked as TROVE-2017-012 and CVE-2017-8822.
When running as a relay, make sure that we never choose ourselves as a guard. Fixes part of bug 21534; bugfix on 0.3.0.1-alpha. This issue is also tracked as TROVE-2017-012 and CVE-2017-8822.
MAJOR BUG FIXES (BOOTSTRAPPING):
Fetch descriptors aggressively whenever we lack enough to build circuits, regardless of how many descriptors we are missing. Previously, we would delay launching the fetch when we had fewer than 15 missing descriptors, even if some of those descriptors were blocking circuits from building. Fixes bug 23985; bugfix on 0.1.1.11-alpha. The effects of this bug became worse in 0.3.0.3-alpha, when we began treating missing descriptors from our primary guards as a reason to delay circuits.
Don't try fetching microdescriptors from relays that have failed to deliver them in the past. Fixes bug 23817; bugfix on 0.3.0.1-alpha.
MAJOR BUG FIXES (CIRCUIT PREDICTION):
Fix circuit prediction logic so that a client doesn't treat a port as being "handled" by a circuit if that circuit already has isolation settings on it. This change should make Tor clients more responsive by improving their chances of having a pre-created circuit ready for use when a request arrives. Fixes bug 18859; bugfix on 0.2.3.3-alpha.
MAJOR BUG FIXES (EXIT RELAYS, DNS):
Fix an issue causing DNS to fail on high-bandwidth exit nodes, making them nearly unusable. Fixes bugs 21394 and 18580; bugfix on 0.1.2.2-alpha, which introduced eventdns. Thanks to Dhalgren for identifying and finding a workaround to this bug and to Moritz, Arthur Edelstein, and Roger for helping to track it down and analyze it.
MAJOR BUG FIXES (RELAY, CRASH, ASSERTION FAILURE):
Fix a timing-based assertion failure that could occur when the circuit out-of-memory handler freed a connection's output buffer. Fixes bug 23690; bugfix on 0.2.6.1-alpha.
MAJOR BUG FIXES (USABILITY, CONTROL PORT):
Report trusted clock skew indications as bootstrap errors, so controllers can more easily alert users when their clocks are wrong. Fixes bug 23506; bugfix on 0.1.2.6-alpha.
MINOR FEATURES (BRIDGE):
Bridge relays can now set the BridgeDistribution config option to add a "bridge-distribution-request" line to their bridge descriptor, which tells BridgeDB how they'd like their bridge address to be given out. (Note that as of Oct 2017, BridgeDB does not yet implement this feature.) As a side benefit, this feature provides a way to distinguish bridge descriptors from non-bridge descriptors. Implements tickets 18329.
When handling the USERADDR command on an ExtOrPort, warn when the transports provides a USERADDR with no port. In a future version, USERADDR commands of this format may be rejected. Detects problems related to ticket 23080.
MINOR FEATURES (BUG DETECTION):
Log a warning message with a stack trace for any attempt to call get_options() during option validation. This pattern has caused subtle bugs in the past. Closes ticket 22281.
MINOR FEATURES (BUILD, COMPILATION):
The "check-changes" feature is now part of the "make check" tests; we'll use it to try to prevent misformed changes files from accumulating. Closes ticket 23564.
Tor builds should now fail if there are any mismatches between the C type representing a configuration variable and the C type the data-driven parser uses to store a value there. Previously, we needed to check these by hand, which sometimes led to mistakes. Closes ticket 23643.
MINOR FEATURES (CLIENT):
You can now use Tor as a tunneled HTTP proxy: use the new HTTPTunnelPort option to open a port that accepts HTTP CONNECT requests. Closes ticket 22407.
Add an extra check to make sure that we always use the newer guard selection code for picking our guards. Closes ticket 22779.
When downloading (micro)descriptors, don't split the list into multiple requests unless we want at least 32 descriptors. Previously, we split at 4, not 32, which led to significant overhead in HTTP request size and degradation in compression performance. Closes ticket 23220.
Improve log messages when missing descriptors for primary guards. Resolves ticket 23670.
MINOR FEATURES (COMMAND LINE):
Add a new commandline option, --key-expiration, which prints when the current signing key is going to expire. Implements ticket 17639; patch by Isis Lovecruft.
MINOR FEATURES (CONTROL PORT):
If an application tries to use the control port as an HTTP proxy, respond with a meaningful "This is the Tor control port" message, and log the event. Closes ticket 1667. Patch from Ravi Chandra Padmala.
Provide better error message for GETINFO desc/(id|name) when not fetching router descriptors. Closes ticket 5847. Patch by Kevin Butler.
Add GETINFO "{desc,md}/download-enabled", to inform the controller whether Tor will try to download router descriptors and microdescriptors respectively. Closes ticket 22684.
Added new GETINFO targets "ip-to-country/{ipv4,ipv6}-available", so controllers can tell whether the geoip databases are loaded. Closes ticket 23237.
Adds a timestamp field to the CIRC_BW and STREAM_BW bandwidth events. Closes ticket 19254. Patch by "DonnchaC".
MINOR FEATURES (DEVELOPMENT SUPPORT):
Developers can now generate a call-graph for Tor using the "calltool" python program, which post-processes object dumps. It should work okay on many Linux and OSX platforms, and might work elsewhere too. To run it, install calltool from https://gitweb.torproject.org/user/nickm/calltool.git and run "make callgraph". Closes ticket 19307.
MINOR FEATURES (DIRECTORY AUTHORITY):
Make the "Exit" flag assignment only depend on whether the exit policy allows connections to ports 80 and 443. Previously relays would get the Exit flag if they allowed connections to one of these ports and also port 6667. Resolves ticket 23637.
MINOR FEATURES (ED25519):
Add validation function to checks for torsion components in ed25519 public keys, used by prop224 client-side code. Closes ticket 22006. Math help by Ian Goldberg.
MINOR FEATURES (EXIT RELAY, DNS):
Improve the clarity and safety of the log message from evdns when receiving an apparently spoofed DNS reply. Closes ticket 3056.
MINOR FEATURES (FALLBACK DIRECTORY MIRRORS):
The fallback directory list has been re-generated based on the current status of the network. Tor uses fallback directories to bootstrap when it doesn't yet have up-to-date directory information. Closes ticket 24801.
Make the default DirAuthorityFallbackRate 0.1, so that clients prefer to bootstrap from fallback directory mirrors. This is a follow-up to 24679, which removed weights from the default fallbacks. Implements ticket 24681.
MINOR FEATURES (GEOIP):
Update geoip and geoip6 to the January 5 2018 Maxmind GeoLite2 Country database.
MINOR FEATURES (INTEGRATION, HARDENING):
Add a new NoExec option to prevent Tor from running other programs. When this option is set to 1, Tor will never try to run another program, regardless of the settings of PortForwardingHelper, ClientTransportPlugin, or ServerTransportPlugin. Once NoExec is set, it cannot be disabled without restarting Tor. Closes ticket 22976.
MINOR FEATURES (LINUX SECCOMP2 SANDBOX):
Update the sandbox rules so that they should now work correctly with Glibc 2.26. Closes ticket 24315.
MINOR FEATURES (LOGGING):
Provide better warnings when the getrandom() syscall fails. Closes ticket 24500.
Downgrade a pair of log messages that could occur when an exit's resolver gave us an unusual (but not forbidden) response. Closes ticket 24097.
Improve the message we log when re-enabling circuit build timeouts after having received a consensus. Closes ticket 20963.
Log more circuit information whenever we are about to try to package a relay cell on a circuit with a nonexistent n_chan. Attempt to diagnose ticket 8185.
Improve info-level log identification of particular circuits, to help with debugging. Closes ticket 23645.
Improve the warning message for specifying a relay by nickname. The previous message implied that nickname registration was still part of the Tor network design, which it isn't. Closes ticket 20488.
If the sandbox filter fails to load, suggest to the user that their kernel might not support seccomp2. Closes ticket 23090.
MINOR FEATURES (ONION SERVICE, CIRCUIT, LOGGING):
Improve logging of many callsite in the circuit subsystem to print the circuit identifier(s).
Log when we cleanup an intro point from a service so we know when and for what reason it happened. Closes ticket 23604.
MINOR FEATURES (PORTABILITY):
Tor now compiles correctly on arm64 with libseccomp-dev installed. (It doesn't yet work with the sandbox enabled.) Closes ticket 24424.
Check at configure time whether uint8_t is the same type as unsigned char. Lots of existing code already makes this assumption, and there could be strict aliasing issues if the assumption is violated. Closes ticket 22410.
MINOR FEATURES (RELAY):
When choosing which circuits can be expired as unused, consider circuits from clients even if those clients used regular CREATE cells to make them; and do not consider circuits from relays even if they were made with CREATE_FAST. Part of ticket 22805.
Reject attempts to use relative file paths when RunAsDaemon is set. Previously, Tor would accept these, but the directory- changing step of RunAsDaemon would give strange and/or confusing results. Closes ticket 22731.
MINOR FEATURES (RELAY STATISTICS):
Change relay bandwidth reporting stats interval from 4 hours to 24 hours in order to reduce the efficiency of guard discovery attacks. Fixes ticket 23856.
MINOR FEATURES (REVERTED DEPRECATIONS):
The ClientDNSRejectInternalAddresses flag can once again be set in non-testing Tor networks, so long as they do not use the default directory authorities. This change also removes the deprecation of this flag from 0.2.9.2-alpha. Closes ticket 21031.
MINOR FEATURES (ROBUSTNESS):
Change several fatal assertions when flushing buffers into non- fatal assertions, to prevent any recurrence of 23690.
MINOR FEATURES (STARTUP, SAFETY):
When configured to write a PID file, Tor now exits if it is unable to do so. Previously, it would warn and continue. Closes ticket 20119.
MINOR FEATURES (STATIC ANALYSIS):
The BUG() macro has been changed slightly so that Coverity no longer complains about dead code if the bug is impossible. Closes ticket 23054.
MINOR FEATURES (TESTING):
Our fuzzing tests now test the encrypted portions of v3 onion service descriptors. Implements more of 21509.
Add a unit test to make sure that our own generated platform string will be accepted by directory authorities. Closes ticket 22109.
The default chutney network tests now include tests for the v3 onion service design. Make sure you have the latest version of chutney if you want to run these. Closes ticket 22437.
Add a unit test to verify that we can parse a hardcoded v2 onion service descriptor. Closes ticket 15554.
MINOR BUG FIXES (ADDRESS SELECTION):
When the fascist_firewall_choose_address_ functions don't find a reachable address, set the returned address to the null address and port. This is a precautionary measure, because some callers do not check the return value. Fixes bug 24736; bugfix on 0.2.8.2-alpha.
MINOR BUG FIXES (BOOTSTRAPPING):
When warning about state file clock skew, report the correct direction for the detected skew. Fixes bug 23606; bugfix on 0.2.8.1-alpha.
MINOR BUG FIXES (BRIDGE CLIENTS, BOOTSTRAP):
Retry directory downloads when we get our first bridge descriptor during bootstrap or while reconnecting to the network. Keep retrying every time we get a bridge descriptor, until we have a reachable bridge. Fixes part of bug 24367; bugfix on 0.2.0.3-alpha.
Stop delaying bridge descriptor fetches when we have cached bridge descriptors. Instead, only delay bridge descriptor fetches when we have at least one reachable bridge. Fixes part of bug 24367; bugfix on 0.2.0.3-alpha.
Stop delaying directory fetches when we have cached bridge descriptors. Instead, only delay bridge descriptor fetches when all our bridges are definitely unreachable. Fixes part of bug 24367; bugfix on 0.2.0.3-alpha.
MINOR BUG FIXES (BRIDGE):
Overwrite the bridge address earlier in the process of retrieving its descriptor, to make sure we reach it on the configured address. Fixes bug 20532; bugfix on 0.2.0.10-alpha.
MINOR BUG FIXES (BUILD, COMPILATION):
Fix a compilation warning when building with zstd support on 32-bit platforms. Fixes bug 23568; bugfix on 0.3.1.1-alpha. Found and fixed by Andreas Stieger.
When searching for OpenSSL, don't accept any OpenSSL library that lacks TLSv1_1_method(): Tor doesn't build with those versions. Additionally, look in /usr/local/opt/openssl, if it's present. These changes together repair the default build on OSX systems with Homebrew installed. Fixes bug 23602; bugfix on 0.2.7.2-alpha.
Fix a signed/unsigned comparison warning introduced by our fix to TROVE-2017-009. Fixes bug 24480; bugfix on 0.2.5.16.
Fix a memory leak warning in one of the libevent-related configuration tests that could occur when manually specifying -fsanitize=address. Fixes bug 24279; bugfix on 0.3.0.2-alpha. Found and patched by Alex Xu.
Fix unused-variable warnings in donna's Curve25519 SSE2 code. Fixes bug 22895; bugfix on 0.2.7.2-alpha.
MINOR BUG FIXES (CERTIFICATE HANDLING):
Fix a time handling bug in Tor certificates set to expire after the year 2106. Fixes bug 23055; bugfix on 0.3.0.1-alpha. Found by Coverity as CID 1415728.
MINOR BUG FIXES (CLIENT):
By default, do not enable storage of client-side DNS values. These values were unused by default previously, but they should not have been cached at all. Fixes bug 24050; bugfix on 0.2.6.3-alpha.
MINOR BUG FIXES (CLIENT, USABILITY):
Refrain from needlessly rejecting SOCKS5-with-hostnames and SOCKS4a requests that contain IP address strings, even when SafeSocks in enabled, as this prevents user from connecting to known IP addresses without relying on DNS for resolving. SafeSocks still rejects SOCKS connections that connect to IP addresses when those addresses are _not_ encoded as hostnames. Fixes bug 22461; bugfix on Tor 0.2.6.2-alpha.
MINOR BUG FIXES (CODE CORRECTNESS):
Call htons() in extend_cell_format() for encoding a 16-bit value. Previously we used ntohs(), which happens to behave the same on all the platforms we support, but which isn't really correct. Fixes bug 23106; bugfix on 0.2.4.8-alpha.
For defense-in-depth, make the controller's write_escaped_data() function robust to extremely long inputs. Fixes bug 19281; bugfix on 0.1.1.1-alpha. Reported by Guido Vranken.
Fix several places in our codebase where a C compiler would be likely to eliminate a check, based on assuming that undefined behavior had not happened elsewhere in the code. These cases are usually a sign of redundant checking or dubious arithmetic. Found by Georg Koppen using the "STACK" tool from Wang, Zeldovich, Kaashoek, and Solar-Lezama. Fixes bug 24423; bugfix on various Tor versions.
MINOR BUG FIXES (COMPRESSION):
Handle a pathological case when decompressing Zstandard data when the output buffer size is zero. Fixes bug 23551; bugfix on 0.3.1.1-alpha.
MINOR BUG FIXES (CONSENSUS EXPIRY):
Check for adequate directory information correctly. Previously, Tor would reconsider whether it had sufficient directory information every 2 minutes. Fixes bug 23091; bugfix on 0.2.0.19-alpha.
MINOR BUG FIXES (CONTROL PORT, LINUX SECCOMP2 SANDBOX):
Avoid a crash when attempting to use the seccomp2 sandbox together with the OwningControllerProcess feature. Fixes bug 24198; bugfix on 0.2.5.1-alpha.
MINOR BUG FIXES (CONTROL PORT, ONION SERVICES):
Report "FAILED" instead of "UPLOAD_FAILED" "FAILED" for the HS_DESC event when a service is not able to upload a descriptor. Fixes bug 24230; bugfix on 0.2.7.1-alpha.
MINOR BUG FIXES (DIRECTORY CACHE):
Recover better from empty or corrupt files in the consensus cache directory. Fixes bug 24099; bugfix on 0.3.1.1-alpha.
When a consensus diff calculation is only partially successful, only record the successful parts as having succeeded. Partial success can happen if (for example) one compression method fails but the others succeed. Previously we misrecorded all the calculations as having succeeded, which would later cause a nonfatal assertion failure. Fixes bug 24086; bugfix on 0.3.1.1-alpha.
MINOR BUG FIXES (DIRECTORY CLIENT):
On failure to download directory information, delay retry attempts by a random amount based on the "decorrelated jitter" algorithm. Our previous delay algorithm tended to produce extra-long delays too easily. Fixes bug 23816; bugfix on 0.2.9.1-alpha.
MINOR BUG FIXES (DIRECTORY PROTOCOL):
Directory servers now include a "Date:" http header for response codes other than 200. Clients starting with a skewed clock and a recent consensus were getting "304 Not modified" responses from directory authorities, so without the Date header, the client would never hear about a wrong clock. Fixes bug 23499; bugfix on 0.0.8rc1.
Make clients wait for 6 seconds before trying to download a consensus from an authority. Fixes bug 17750; bugfix on 0.2.8.1-alpha.
MINOR BUG FIXES (DOCUMENTATION):
Document better how to read gcov, and what our gcov postprocessing scripts do. Fixes bug 23739; bugfix on 0.2.9.1-alpha.
Fix manpage to not refer to the obsolete (and misspelled) UseEntryGuardsAsDirectoryGuards parameter in the description of NumDirectoryGuards. Fixes bug 23611; bugfix on 0.2.4.8-alpha.
MINOR BUG FIXES (DOS-RESISTANCE):
If future code asks if there are any running bridges, without checking if bridges are enabled, log a BUG warning rather than crashing. Fixes bug 23524; bugfix on 0.3.0.1-alpha.
MINOR BUG FIXES (ENTRY GUARDS):
Tor now updates its guard state when it reads a consensus regardless of whether it's missing descriptors. That makes tor use its primary guards to fetch descriptors in some edge cases where it would previously have used fallback directories. Fixes bug 23862; bugfix on 0.3.0.1-alpha.
MINOR BUG FIXES (FORMAT STRICTNESS):
Restrict several data formats to decimal. Previously, the BuildTimeHistogram entries in the state file, the "bw=" entries in the bandwidth authority file, and the process IDs passed to the __OwningControllerProcess option could all be specified in hex or octal as well as in decimal. This was not an intentional feature. Fixes bug 22802; bug fixes on 0.2.2.1-alpha, 0.2.2.2-alpha, and 0.2.2.28-beta.
MINOR BUG FIXES (HEARTBEAT):
If we fail to write a heartbeat message, schedule a retry for the minimum heartbeat interval number of seconds in the future. Fixes bug 19476; bugfix on 0.2.3.1-alpha.
MINOR BUG FIXES (LOGGING):
Suppress a log notice when relay descriptors arrive. We already have a bootstrap progress for this so no need to log notice everytime tor receives relay descriptors. Microdescriptors behave the same. Fixes bug 23861; bugfix on 0.2.8.2-alpha.
Remove duplicate log messages regarding opening non-local SocksPorts upon parsing config and opening listeners at startup. Fixes bug 4019; bugfix on 0.2.3.3-alpha.
Use a more comprehensible log message when telling the user they've excluded every running exit node. Fixes bug 7890; bugfix on 0.2.2.25-alpha.
When logging the number of descriptors we intend to download per directory request, do not log a number higher than then the number of descriptors we're fetching in total. Fixes bug 19648; bugfix on 0.1.1.8-alpha.
When warning about a directory owned by the wrong user, log the actual name of the user owning the directory. Previously, we'd log the name of the process owner twice. Fixes bug 23487; bugfix on 0.2.9.1-alpha.
Fix some messages on unexpected errors from the seccomp2 library. Fixes bug 22750; bugfix on 0.2.5.1-alpha. Patch from "cypherpunks".
The tor specification says hop counts are 1-based, so fix two log messages that mistakenly logged 0-based hop counts. Fixes bug 18982; bugfix on 0.2.6.2-alpha and 0.2.4.5-alpha. Patch by teor. Credit to Xiaofan Li for reporting this issue.
MINOR BUG FIXES (LOGGING, RELAY SHUTDOWN, ANNOYANCE):
When a circuit is marked for close, do not attempt to package any cells for channels on that circuit. Previously, we would detect this condition lower in the call stack, when we noticed that the circuit had no attached channel, and log an annoying message. Fixes bug 8185; bugfix on 0.2.5.4-alpha.
MINOR BUG FIXES (MEMORY SAFETY, DEFENSIVE PROGRAMMING):
Clear the target address when node_get_prim_orport() returns early. Fixes bug 23874; bugfix on 0.2.8.2-alpha.
MINOR BUG FIXES (MEMORY USAGE):
When queuing DESTROY cells on a channel, only queue the circuit-id and reason fields: not the entire 514-byte cell. This fix should help mitigate any bugs or attacks that fill up these queues, and free more RAM for other uses. Fixes bug 24666; bugfix on 0.2.5.1-alpha.
MINOR BUG FIXES (NETWORK LAYER):
When closing a connection via close_connection_immediately(), we mark it as "not blocked on bandwidth", to prevent later calls from trying to unblock it, and give it permission to read. This fixes a backtrace warning that can happen on relays under various circumstances. Fixes bug 24167; bugfix on 0.1.0.1-rc.
MINOR BUG FIXES (ONION SERVICES):
The introduction circuit was being timed out too quickly while waiting for the rendezvous circuit to complete. Keep the intro circuit around longer instead of timing out and reopening new ones constantly. Fixes bug 23681; bugfix on 0.2.4.8-alpha.
Rename the consensus parameter "hsdir-interval" to "hsdir_interval" so it matches dir-spec.txt. Fixes bug 24262; bugfix on 0.3.1.1-alpha.
When handling multiple SOCKS request for the same .onion address, only fetch the service descriptor once.
Avoid a possible double close of a circuit by the intro point on error of sending the INTRO_ESTABLISHED cell. Fixes bug 23610; bugfix on 0.3.0.1-alpha.
When reloading configured onion services, copy all information from the old service object. Previously, some data was omitted, causing delays in descriptor upload, and other bugs. Fixes bug 23790; bugfix on 0.2.1.9-alpha.
MINOR BUG FIXES (PATH SELECTION):
When selecting relays by bandwidth, avoid a rounding error that could sometimes cause load to be imbalanced incorrectly. Previously, we would always round upwards; now, we round towards the nearest integer. This had the biggest effect when a relay's weight adjustments should have given it weight 0, but it got weight 1 instead. Fixes bug 23318; bugfix on 0.2.4.3-alpha.
When calculating the fraction of nodes that have descriptors, and all nodes in the network have zero bandwidths, count the number of nodes instead. Fixes bug 23318; bugfix on 0.2.4.10-alpha.
Actually log the total bandwidth in compute_weighted_bandwidths(). Fixes bug 24170; bugfix on 0.2.4.3-alpha.
MINOR BUG FIXES (PORTABILITY):
Stop using the PATH_MAX variable, which is not defined on GNU Hurd. Fixes bug 23098; bugfix on 0.3.1.1-alpha.
Fix a bug in the bit-counting parts of our timing-wheel code on MSVC. (Note that MSVC is still not a supported build platform, due to cyptographic timing channel risks.) Fixes bug 24633; bugfix on 0.2.9.1-alpha.
MINOR BUG FIXES (RELAY):
When uploading our descriptor for the first time after startup, report the reason for uploading as "Tor just started" rather than leaving it blank. Fixes bug 22885; bugfix on 0.2.3.4-alpha.
Avoid unnecessary calls to directory_fetches_from_authorities() on relays, to prevent spurious address resolutions and descriptor rebuilds. This is a mitigation for bug 21789. Fixes bug 23470; bugfix on in 0.2.8.1-alpha.
Avoid a crash when transitioning from client mode to bridge mode. Previously, we would launch the worker threads whenever our "public server" mode changed, but not when our "server" mode changed. Fixes bug 23693; bugfix on 0.2.6.3-alpha.
MINOR BUG FIXES (TESTING):
Fix a spurious fuzzing-only use of an uninitialized value. Found by Brian Carpenter. Fixes bug 24082; bugfix on 0.3.0.3-alpha.
Test that IPv6-only clients can use microdescriptors when running "make test-network-all". Requires chutney master 61c28b9 or later. Closes ticket 24109.
Prevent scripts/test/coverage from attempting to move gcov output to the root directory. Fixes bug 23741; bugfix on 0.2.5.1-alpha.
Capture and detect several "Result does not fit" warnings in unit tests on platforms with 32-bit time_t. Fixes bug 21800; bugfix on 0.2.9.3-alpha.
Fix additional channelpadding unit test failures by using mocked time instead of actual time for all tests. Fixes bug 23608; bugfix on 0.3.1.1-alpha.
Fix a bug in our fuzzing mock replacement for crypto_pk_checksig(), to correctly handle cases where a caller gives it an RSA key of under 160 bits. (This is not actually a bug in Tor itself, but rather in our fuzzing code.) Fixes bug 24247; bugfix on 0.3.0.3-alpha. Found by OSS-Fuzz as issue 4177.
Fix a broken unit test for the OutboundAddress option: the parsing function was never returning an error on failure. Fixes bug 23366; bugfix on 0.3.0.3-alpha.
Fix a signed-integer overflow in the unit tests for dir/download_status_random_backoff, which was untriggered until we fixed bug 17750. Fixes bug 22924; bugfix on 0.2.9.1-alpha.
MINOR BUG FIXES (USABILITY, CONTROL PORT):
Stop making an unnecessary routerlist check in NETINFO clock skew detection; this was preventing clients from reporting NETINFO clock skew to controllers. Fixes bug 23532; bugfix on 0.2.4.4-alpha.
CODE SIMPLIFICATION AND REFACTORING:
Remove various ways of testing circuits and connections for "clientness"; instead, favor channel_is_client(). Part of ticket 22805.
Extract the code for handling newly-open channels into a separate function from the general code to handle channel state transitions. This change simplifies our callgraph, reducing the size of the largest strongly connected component by roughly a factor of two. Closes ticket 22608.
Remove dead code for largely unused statistics on the number of times we've attempted various public key operations. Fixes bug 19871; bugfix on 0.1.2.4-alpha. Fix by Isis Lovecruft.
Remove several now-obsolete functions for asking about old variants directory authority status. Closes ticket 22311; patch from "huyvq".
Remove some of the code that once supported "Named" and "Unnamed" routers. Authorities no longer vote for these flags. Closes ticket 22215.
Rename the obsolete malleable hybrid_encrypt functions used in TAP and old hidden services, to indicate that they aren't suitable for new protocols or formats. Closes ticket 23026.
Replace our STRUCT_OFFSET() macro with offsetof(). Closes ticket 22521. Patch from Neel Chauhan.
Split the enormous circuit_send_next_onion_skin() function into multiple subfunctions. Closes ticket 22804.
Split the portions of the buffer.c module that handle particular protocols into separate modules. Part of ticket 23149.
Use our test macros more consistently, to produce more useful error messages when our unit tests fail. Add coccinelle patches to allow us to re-check for test macro uses. Closes ticket 22497.
DEPRECATED FEATURES:
The ReachableDirAddresses and ClientPreferIPv6DirPort options are now deprecated; they do not apply to relays, and they have had no effect on clients since 0.2.8.x. Closes ticket 19704.
Deprecate HTTPProxy/HTTPProxyAuthenticator config options. They only applies to direct unencrypted HTTP connections to your directory server, which your Tor probably isn't using. Closes ticket 20575.
DOCUMENTATION:
Add notes in man page regarding OS support for the various scheduler types. Attempt to use less jargon in the scheduler section. Closes ticket 24254.
Clarify that the Address option is entirely about setting an advertised IPv4 address. Closes ticket 18891.
Clarify the manpage's use of the term "address" to clarify what kind of address is intended. Closes ticket 21405.
Document that onion service subdomains are allowed, and ignored. Closes ticket 18736.
Clarify in the manual that "Sandbox 1" is only supported on Linux kernels. Closes ticket 22677.
Document all values of PublishServerDescriptor in the manpage. Closes ticket 15645.
Improve the documentation for the directory port part of the DirAuthority line. Closes ticket 20152.
Restore documentation for the authorities' "approved-routers" file. Closes ticket 21148.
REMOVED FEATURES:
The AllowDotExit option has been removed as unsafe. It has been deprecated since 0.2.9.2-alpha. Closes ticket 23426.
The ClientDNSRejectInternalAddresses flag can no longer be set on non-testing networks. It has been deprecated since 0.2.9.2-alpha. Closes ticket 21031.
The controller API no longer includes an AUTHDIR_NEWDESCS event: nobody was using it any longer. Closes ticket 22377.

New in Tor 0.3.2.8 RC (Dec 21, 2017)

New in Tor 0.3.2.7 RC (Dec 15, 2017)

Major bug fixes (circuit prediction):
Fix circuit prediction logic so that a client doesn't treat a port as being "handled" by a circuit if that circuit already has isolation settings on it. This change should make Tor clients more responsive by improving their chances of having a pre-created circuit ready for use when a request arrives. Fixes bug 18859; bugfix on 0.2.3.3-alpha.
Minor features (logging):
Provide better warnings when the getrandom() syscall fails. Closes ticket 24500.
Minor features (portability):
Tor now compiles correctly on arm64 with libseccomp-dev installed. (It doesn't yet work with the sandbox enabled.) Closes ticket 24424.
Minor bug fixes (bridge clients, bootstrap):
Retry directory downloads when we get our first bridge descriptor during bootstrap or while reconnecting to the network. Keep retrying every time we get a bridge descriptor, until we have a reachable bridge. Fixes part of bug 24367; bugfix on 0.2.0.3-alpha.
Stop delaying bridge descriptor fetches when we have cached bridge descriptors. Instead, only delay bridge descriptor fetches when we have at least one reachable bridge. Fixes part of bug 24367; bugfix on 0.2.0.3-alpha.
Stop delaying directory fetches when we have cached bridge descriptors. Instead, only delay bridge descriptor fetches when all our bridges are definitely unreachable. Fixes part of bug 24367; bugfix on 0.2.0.3-alpha.
Minor bug fixes (compilation):
Fix a signed/unsigned comparison warning introduced by our fix to TROVE-2017-009. Fixes bug 24480; bugfix on 0.2.5.16.
Minor bug fixes (correctness):
Fix several places in our codebase where a C compiler would be likely to eliminate a check, based on assuming that undefined behavior had not happened elsewhere in the code. These cases are usually a sign of redundant checking or dubious arithmetic. Found by Georg Koppen using the "STACK" tool from Wang, Zeldovich, Kaashoek, and Solar-Lezama. Fixes bug 24423; bugfix on various Tor versions.
Minor bug fixes (onion service v3):
Fix a race where an onion service would launch a new intro circuit after closing an old one, but fail to register it before freeing the previously closed circuit. This bug was making the service unable to find the established intro circuit and thus not upload its descriptor, thus making a service unavailable for up to 24 hours. Fixes bug 23603; bugfix on 0.3.2.1-alpha.
Minor bug fixes (scheduler, KIST):
Properly set the scheduler state of an unopened channel in the KIST scheduler main loop. This prevents a harmless but annoying log warning. Fixes bug 24502; bugfix on 0.3.2.4-alpha.
Avoid a possible integer overflow when computing the available space on the TCP buffer of a channel. This had no security implications; but could make KIST allow too many cells on a saturated connection. Fixes bug 24590; bugfix on 0.3.2.1-alpha.
Downgrade to "info" a harmless warning about the monotonic time moving backwards: This can happen on platform not supporting monotonic time. Fixes bug 23696; bugfix on 0.3.2.1-alpha.

New in Tor 0.3.2.6 Alpha (Dec 1, 2017)

This version of Tor is the latest in the 0.3.2 alpha series. It
includes fixes for several important security issues. All Tor users
should upgrade to this release, or to one of the other releases coming
out today.
Major bug fixes (security):
Fix a denial of service bug where an attacker could use a malformed directory object to cause a Tor instance to pause while OpenSSL would try to read a passphrase from the terminal. (Tor instances run without a terminal, which is the case for most Tor packages, are not impacted.) Fixes bug 24246; bugfix on every version of Tor. Also tracked as TROVE-2017-011 and CVE-2017-8821. Found by OSS-Fuzz as testcase 6360145429790720.
Fix a denial of service issue where an attacker could crash a directory authority using a malformed router descriptor. Fixes bug 24245; bugfix on 0.2.9.4-alpha. Also tracked as TROVE-2017-010 and CVE-2017-8820.
When checking for replays in the INTRODUCE1 cell data for a (legacy) onion service, correctly detect replays in the RSA- encrypted part of the cell. We were previously checking for replays on the entire cell, but those can be circumvented due to the malleability of Tor's legacy hybrid encryption. This fix helps prevent a traffic confirmation attack. Fixes bug 24244; bugfix on 0.2.4.1-alpha. This issue is also tracked as TROVE-2017-009 and CVE-2017-8819.
Major bug fixes (security, onion service v2):
Fix a use-after-free error that could crash v2 Tor onion services when they failed to open circuits while expiring introduction points. Fixes bug 24313; bugfix on 0.2.7.2-alpha. This issue is also tracked as TROVE-2017-013 and CVE-2017-8823.
Major bug fixes (security, relay):
When running as a relay, make sure that we never build a path through ourselves, even in the case where we have somehow lost the version of our descriptor appearing in the consensus. Fixes part of bug 21534; bugfix on 0.2.0.1-alpha. This issue is also tracked as TROVE-2017-012 and CVE-2017-8822.
When running as a relay, make sure that we never choose ourselves as a guard. Fixes part of bug 21534; bugfix on 0.3.0.1-alpha. This issue is also tracked as TROVE-2017-012 and CVE-2017-8822.
Minor feature (relay statistics):
Change relay bandwidth reporting stats interval from 4 hours to 24 hours in order to reduce the efficiency of guard discovery attacks. Fixes ticket 23856.
Minor features (directory authority):
Add an IPv6 address for the "bastet" directory authority. Closes ticket 24394.
Minor bug fixes (client):
By default, do not enable storage of client-side DNS values. These values were unused by default previously, but they should not have been cached at all. Fixes bug 24050; bugfix on 0.2.6.3-alpha.

New in Tor 0.3.1.9 (Dec 1, 2017)

Tor 0.3.1.9 backports important security and stability fixes from the
0.3.2 development series. All Tor users should upgrade to this
release, or to another of the releases coming out today.
Major bug fixes (security, backport from 0.3.2.6-alpha):
Fix a denial of service bug where an attacker could use a malformed directory object to cause a Tor instance to pause while OpenSSL would try to read a passphrase from the terminal. (Tor instances run without a terminal, which is the case for most Tor packages, are not impacted.) Fixes bug 24246; bug fix on every version of Tor. Also tracked as TROVE-2017-011 and CVE-2017-8821. Found by OSS-Fuzz as testcase 6360145429790720.
Fix a denial of service issue where an attacker could crash a directory authority using a malformed router descriptor. Fixes bug 24245; bug fix on 0.2.9.4-alpha. Also tracked as TROVE-2017-010 and CVE-2017-8820.
When checking for replays in the INTRODUCE1 cell data for a (legacy) onion service, correctly detect replays in the RSA- encrypted part of the cell. We were previously checking for replays on the entire cell, but those can be circumvented due to the malleability of Tor's legacy hybrid encryption. This fix helps prevent a traffic confirmation attack. Fixes bug 24244; bug fix on 0.2.4.1-alpha. This issue is also tracked as TROVE-2017-009 and CVE-2017-8819.
Major bug fixes (security, onion service v2, backport from 0.3.2.6-alpha):
Fix a use-after-free error that could crash v2 Tor onion services when they failed to open circuits while expiring introduction points. Fixes bug 24313; bug fix on 0.2.7.2-alpha. This issue is also tracked as TROVE-2017-013 and CVE-2017-8823.
Major bug fixes (security, relay, backport from 0.3.2.6-alpha):
When running as a relay, make sure that we never build a path through ourselves, even in the case where we have somehow lost the version of our descriptor appearing in the consensus. Fixes part of bug 21534; bug fix on 0.2.0.1-alpha. This issue is also tracked as TROVE-2017-012 and CVE-2017-8822.
When running as a relay, make sure that we never choose ourselves as a guard. Fixes part of bug 21534; bug fix on 0.3.0.1-alpha. This issue is also tracked as TROVE-2017-012 and CVE-2017-8822.
Major bug fixes (exit relays, DNS, backport from 0.3.2.4-alpha):
Fix an issue causing DNS to fail on high-bandwidth exit nodes, making them nearly unusable. Fixes bugs 21394 and 18580; bug fix on 0.1.2.2-alpha, which introduced eventdns. Thanks to Dhalgren for identifying and finding a workaround to this bug and to Moritz, Arthur Edelstein, and Roger for helping to track it down and analyze it.
Minor features (bridge):
Bridges now include notice in their descriptors that they are bridges, and notice of their distribution status, based on their publication settings. Implements ticket 18329. For more fine- grained control of how a bridge is distributed, upgrade to 0.3.2.x or later.
Minor features (directory authority, backport from 0.3.2.6-alpha):
Add an IPv6 address for the "bastet" directory authority. Closes ticket 24394.
Minor features (geoip):
Update geoip and geoip6 to the November 6 2017 Maxmind GeoLite2 Country database.
Minor bug fix (relay address resolution, backport from 0.3.2.1-alpha):
Avoid unnecessary calls to directory_fetches_from_authorities() on relays, to prevent spurious address resolutions and descriptor rebuilds. This is a mitigation for bug 21789. Fixes bug 23470; bug fix on in 0.2.8.1-alpha.
Minor bug fixes (compilation, backport from 0.3.2.1-alpha):
Fix unused variable warnings in donna's Curve25519 SSE2 code. Fixes bug 22895; bug fix on 0.2.7.2-alpha.
Minor bug fixes (logging, relay shutdown, annoyance, backport from 0.3.2.2-alpha):
When a circuit is marked for close, do not attempt to package any cells for channels on that circuit. Previously, we would detect this condition lower in the call stack, when we noticed that the circuit had no attached channel, and log an annoying message. Fixes bug 8185; bug fix on 0.2.5.4-alpha.
Minor bug fixes (onion service, backport from 0.3.2.5-alpha):
Rename the consensus parameter "hsdir-interval" to "hsdir_interval" so it matches dir-spec.txt. Fixes bug 24262; bug fix on 0.3.1.1-alpha.
Minor bug fixes (relay, crash, backport from 0.3.2.4-alpha):
Avoid a crash when transitioning from client mode to bridge mode. Previously, we would launch the worker threads whenever our "public server" mode changed, but not when our "server" mode changed. Fixes bug 23693; bug fix on 0.2.6.3-alpha.

New in Tor 0.3.2.5 Alpha (Nov 22, 2017)

Tor 0.3.2.5-alpha is the fifth alpha release in the 0.3.2.x series. It fixes several stability and reliability bugs, including a fix for intermittent bootstrapping failures that some people have been seeing since the 0.3.0.x series.
Please test this alpha out -- many of these fixes will soon be backported to stable Tor versions if no additional bugs are found in them.
Major bug fixes (bootstrapping):
Fetch descriptors aggressively whenever we lack enough to build circuits, regardless of how many descriptors we are missing. Previously, we would delay launching the fetch when we had fewer than 15 missing descriptors, even if some of those descriptors were blocking circuits from building. Fixes bug 23985; bugfix on 0.1.1.11-alpha. The effects of this bug became worse in 0.3.0.3-alpha, when we began treating missing descriptors from our primary guards as a reason to delay circuits.
Don't try fetching microdescriptors from relays that have failed to deliver them in the past. Fixes bug 23817; bugfix on 0.3.0.1-alpha.
Minor features (directory authority):
Make the "Exit" flag assignment only depend on whether the exit policy allows connections to ports 80 and 443. Previously relays would get the Exit flag if they allowed connections to one of these ports and also port 6667. Resolves ticket 23637.
Minor features (geoip):
Update geoip and geoip6 to the November 6 2017 Maxmind GeoLite2 Country database.
Minor features (linux seccomp2 sandbox):
Update the sandbox rules so that they should now work correctly with Glibc 2.26. Closes ticket 24315.
Minor features (logging):
Downgrade a pair of log messages that could occur when an exit's resolver gave us an unusual (but not forbidden) response. Closes ticket 24097.
Improve the message we log when re-enabling circuit build timeouts after having received a consensus. Closes ticket 20963.
Minor bug fixes (compilation):
Fix a memory leak warning in one of the libevent-related configuration tests that could occur when manually specifying -fsanitize=address. Fixes bug 24279; bugfix on 0.3.0.2-alpha. Found and patched by Alex Xu.
When detecting OpenSSL on Windows from our configure script, make sure to try linking with the ws2_32 library. Fixes bug 23783; bugfix on 0.3.2.2-alpha.
Minor bug fixes (control port, linux seccomp2 sandbox):
Avoid a crash when attempting to use the seccomp2 sandbox together with the OwningControllerProcess feature. Fixes bug 24198; bugfix on 0.2.5.1-alpha.
Minor bug fixes (control port, onion services):
Report "FAILED" instead of "UPLOAD_FAILED" "FAILED" for the HS_DESC event when a service is not able to upload a descriptor. Fixes bug 24230; bugfix on 0.2.7.1-alpha.
Minor bug fixes (directory cache):
Recover better from empty or corrupt files in the consensus cache directory. Fixes bug 24099; bugfix on 0.3.1.1-alpha.
When a consensus diff calculation is only partially successful, only record the successful parts as having succeeded. Partial success can happen if (for example) one compression method fails but the others succeed. Previously we misrecorded all the calculations as having succeeded, which would later cause a nonfatal assertion failure. Fixes bug 24086; bugfix on 0.3.1.1-alpha.
Minor bug fixes (logging):
Only log once if we notice that KIST support is gone. Fixes bug 24158; bugfix on 0.3.2.1-alpha.
Suppress a log notice when relay descriptors arrive. We already have a bootstrap progress for this so no need to log notice everytime tor receives relay descriptors. Microdescriptors behave the same. Fixes bug 23861; bugfix on 0.2.8.2-alpha.
Minor bug fixes (network layer):
When closing a connection via close_connection_immediately(), we mark it as "not blocked on bandwidth", to prevent later calls from trying to unblock it, and give it permission to read. This fixes a backtrace warning that can happen on relays under various circumstances. Fixes bug 24167; bugfix on 0.1.0.1-rc.
Minor bug fixes (onion services):
The introduction circuit was being timed out too quickly while waiting for the rendezvous circuit to complete. Keep the intro circuit around longer instead of timing out and reopening new ones constantly. Fixes bug 23681; bugfix on 0.2.4.8-alpha.
Rename the consensus parameter "hsdir-interval" to "hsdir_interval" so it matches dir-spec.txt. Fixes bug 24262; bugfix on 0.3.1.1-alpha.
Silence a warning about failed v3 onion descriptor uploads that can happen naturally under certain edge cases. Fixes part of bug 23662; bugfix on 0.3.2.1-alpha.
Minor bug fixes (tests):
Fix a memory leak in one of the bridge-distribution test cases. Fixes bug 24345; bugfix on 0.3.2.3-alpha.
Fix a bug in our fuzzing mock replacement for crypto_pk_checksig(), to correctly handle cases where a caller gives it an RSA key of under 160 bits. (This is not actually a bug in Tor itself, but rather in our fuzzing code.) Fixes bug 24247; bugfix on 0.3.0.3-alpha. Found by OSS-Fuzz as issue 4177.
Documentation:
Add notes in man page regarding OS support for the various scheduler types. Attempt to use less jargon in the scheduler section. Closes ticket 24254.

New in Tor 0.3.2.4 Alpha (Nov 9, 2017)

Tor 0.3.2.4-alpha is the fourth alpha release in the 0.3.2.x series. It fixes several stability and reliability bugs, especially including a major reliability issue that has been plaguing fast exit relays in
recent months.
Major bug fixes (exit relays, DNS):
Fix an issue causing DNS to fail on high-bandwidth exit nodes, making them nearly unusable. Fixes bugs 21394 and 18580; bugfix on 0.1.2.2-alpha, which introduced eventdns. Thanks to Dhalgren for identifying and finding a workaround to this bug and to Moritz, Arthur Edelstein, and Roger for helping to track it down and analyze it.
Major bug fixes (scheduler, channel):
Stop processing scheduled channels if they closed while flushing cells. This can happen if the write on the connection fails leading to the channel being closed while in the scheduler loop. Fixes bug 23751; bugfix on 0.3.2.1-alpha.
Minor features (logging, scheduler):
Introduce a SCHED_BUG() function to log extra information about the scheduler state if we ever catch a bug in the scheduler. Closes ticket 23753.
Minor features (removed deprecations):
The ClientDNSRejectInternalAddresses flag can once again be set in non-testing Tor networks, so long as they do not use the default directory authorities. This change also removes the deprecation of this flag from 0.2.9.2-alpha. Closes ticket 21031.
Minor features (testing):
Our fuzzing tests now test the encrypted portions of v3 onion service descriptors. Implements more of 21509.
Minor bug fixes (directory client):
On failure to download directory information, delay retry attempts by a random amount based on the "decorrelated jitter" algorithm. Our previous delay algorithm tended to produce extra-long delays too easily. Fixes bug 23816; bugfix on 0.2.9.1-alpha.
Minor bug fixes (IPv6, v3 single onion services):
Remove buggy code for IPv6-only v3 single onion services, and reject attempts to configure them. This release supports IPv4, dual-stack, and IPv6-only v3 onion services; and IPv4 and dual- stack v3 single onion services. Fixes bug 23820; bugfix on 0.3.2.1-alpha.
Minor bug fixes (logging, relay):
Give only a protocol warning when the ed25519 key is not consistent between the descriptor and microdescriptor of a relay. This can happen, for instance, if the relay has been flagged NoEdConsensus. Fixes bug 24025; bugfix on 0.3.2.1-alpha.
Minor bug fixes (manpage, onion service):
Document that the HiddenServiceNumIntroductionPoints option is 0-10 for v2 services and 0-20 for v3 services. Fixes bug 24115; bugfix on 0.3.2.1-alpha.
Minor bug fixes (memory leaks):
Fix a minor memory leak at exit in the KIST scheduler. This bug should have no user-visible impact. Fixes bug 23774; bugfix on 0.3.2.1-alpha.
Fix a memory leak when decrypting a badly formatted v3 onion service descriptor. Fixes bug 24150; bugfix on 0.3.2.1-alpha. Found by OSS-Fuzz; this is OSS-Fuzz issue 3994.
Minor bug fixes (onion services):
Cache some needed onion service client information instead of constantly computing it over and over again. Fixes bug 23623; bugfix on 0.3.2.1-alpha.
Properly retry HSv3 descriptor fetches when missing required directory information. Fixes bug 23762; bugfix on 0.3.2.1-alpha.
Minor bug fixes (path selection):
When selecting relays by bandwidth, avoid a rounding error that could sometimes cause load to be imbalanced incorrectly. Previously, we would always round upwards; now, we round towards the nearest integer. This had the biggest effect when a relay's weight adjustments should have given it weight 0, but it got weight 1 instead. Fixes bug 23318; bugfix on 0.2.4.3-alpha.
When calculating the fraction of nodes that have descriptors, and all nodes in the network have zero bandwidths, count the number of nodes instead. Fixes bug 23318; bugfix on 0.2.4.10-alpha.
Actually log the total bandwidth in compute_weighted_bandwidths(). Fixes bug 24170; bugfix on 0.2.4.3-alpha.
Minor bug fixes (relay, crash):
Avoid a crash when transitioning from client mode to bridge mode. Previously, we would launch the worker threads whenever our "public server" mode changed, but not when our "server" mode changed. Fixes bug 23693; bugfix on 0.2.6.3-alpha.
Minor bug fixes (testing):
Fix a spurious fuzzing-only use of an uninitialized value. Found by Brian Carpenter. Fixes bug 24082; bugfix on 0.3.0.3-alpha.
Test that IPv6-only clients can use microdescriptors when running "make test-network-all". Requires chutney master 61c28b9 or later. Closes ticket 24109.

New in Tor 0.3.1.8 (Oct 30, 2017)

It includes several bug fixes, including a bugfix for a crash issue that had affected relays under memory pressure. It also adds a new directory authority, Bastet.
Directory authority changes:
Add "Bastet" as a ninth directory authority to the default list. Closes ticket 23910.
The directory authority "Longclaw" has changed its IP address. Closes ticket 23592.
Major bug fixes (relay, crash, assertion failure, backport from 0.3.2.2-alpha):
Fix a timing-based assertion failure that could occur when the circuit out-of-memory handler freed a connection's output buffer. Fixes bug 23690; bugfix on 0.2.6.1-alpha.
Minor features (directory authorities, backport from 0.3.2.2-alpha):
Remove longclaw's IPv6 address, as it will soon change. Authority IPv6 addresses were originally added in 0.2.8.1-alpha. This leaves 3/8 directory authorities with IPv6 addresses, but there are also 52 fallback directory mirrors with IPv6 addresses. Resolves 19760.
Minor features (geoip):
Update geoip and geoip6 to the October 4 2017 Maxmind GeoLite2 Country database.
Minor bug fixes (compilation, backport from 0.3.2.2-alpha):
Fix a compilation warning when building with zstd support on 32-bit platforms. Fixes bug 23568; bugfix on 0.3.1.1-alpha. Found and fixed by Andreas Stieger.
Minor bug fixes (compression, backport from 0.3.2.2-alpha):
Handle a pathological case when decompressing Zstandard data when the output buffer size is zero. Fixes bug 23551; bugfix on 0.3.1.1-alpha.
Minor bug fixes (directory authority, backport from 0.3.2.1-alpha):
Remove the length limit on HTTP status lines that authorities can send in their replies. Fixes bug 23499; bugfix on 0.3.1.6-rc.
Minor bug fixes (hidden service, relay, backport from 0.3.2.2-alpha):
Avoid a possible double close of a circuit by the intro point on error of sending the INTRO_ESTABLISHED cell. Fixes bug 23610; bugfix on 0.3.0.1-alpha.
Minor bug fixes (memory safety, backport from 0.3.2.3-alpha):
Clear the address when node_get_prim_orport() returns early. Fixes bug 23874; bugfix on 0.2.8.2-alpha.
Minor bug fixes (unit tests, backport from 0.3.2.2-alpha):
Fix additional channelpadding unit test failures by using mocked time instead of actual time for all tests. Fixes bug 23608; bugfix on 0.3.1.1-alpha.

New in Tor 0.3.2.3 Alpha (Oct 28, 2017)

Fixes numerous small bugs in earlier versions of 0.3.2.x, and adds a new directory authority, Bastet.
Directory authority changes:
bug fixesAdd "Bastet" as a ninth directory authority to the default list. Closes ticket 23910.
bug fixesThe directory authority "Longclaw" has changed its IP address. Closes ticket 23592.
Minor features (bridge):
bug fixesBridge relays can now set the BridgeDistribution config option to add a "bridge-distribution-request" line to their bridge descriptor, which tells BridgeDB how they'd like their bridge address to be given out. (Note that as of Oct 2017, BridgeDB does not yet implement this feature.) As a side benefit, this feature provides a way to distinguish bridge descriptors from non-bridge descriptors. Implements tickets 18329.
Minor features (client, entry guards):
bug fixesImprove log messages when missing descriptors for primary guards. Resolves ticket 23670.
Minor features (geoip):
bug fixesUpdate geoip and geoip6 to the October 4 2017 Maxmind GeoLite2 Country database.
Minor bug fixes (bridge):
bug fixesOverwrite the bridge address earlier in the process of retrieving its descriptor, to make sure we reach it on the configured address. Fixes bug 20532; bugfix on 0.2.0.10-alpha.
Minor bug fixes (documentation):
bug fixesDocument better how to read gcov, and what our gcov postprocessing scripts do. Fixes bug 23739; bugfix on 0.2.9.1-alpha.
Minor bug fixes (entry guards):
bug fixesTor now updates its guard state when it reads a consensus regardless of whether it's missing descriptors. That makes tor use its primary guards to fetch descriptors in some edge cases where it would previously have used fallback directories. Fixes bug 23862; bugfix on 0.3.0.1-alpha.
Minor bug fixes (hidden service client):
bug fixesWhen handling multiple SOCKS request for the same .onion address, only fetch the service descriptor once.
bug fixesWhen a descriptor fetch fails with a non-recoverable error, close all pending SOCKS requests for that .onion. Fixes bug 23653; bugfix on 0.3.2.1-alpha.
Minor bug fixes (hidden service):
bug fixesAlways regenerate missing hidden service public key files. Prior to this, if the public key was deleted from disk, it wouldn't get recreated. Fixes bug 23748; bugfix on 0.3.2.2-alpha. Patch from "cathugger".
bug fixesMake sure that we have a usable ed25519 key when the intro point relay supports ed25519 link authentication. Fixes bug 24002; bugfix on 0.3.2.1-alpha.
Minor bug fixes (hidden service, v2):
bug fixesWhen reloading configured hidden services, copy all information from the old service object. Previously, some data was omitted, causing delays in descriptor upload, and other bugs. Fixes bug 23790; bugfix on 0.2.1.9-alpha.
Minor bug fixes (memory safety, defensive programming):
bug fixesClear the target address when node_get_prim_orport() returns early. Fixes bug 23874; bugfix on 0.2.8.2-alpha.
Minor bug fixes (relay):
bug fixesAvoid a BUG warning when receiving a dubious CREATE cell while an option transition is in progress. Fixes bug 23952; bugfix on 0.3.2.1-alpha.
Minor bug fixes (testing):
bug fixesAdjust the GitLab CI configuration to more closely match that of Travis CI. Fixes bug 23757; bugfix on 0.3.2.2-alpha.
bug fixesPrevent scripts/test/coverage from attempting to move gcov output to the root directory. Fixes bug 23741; bugfix on 0.2.5.1-alpha.
bug fixesWhen running unit tests as root, skip a test that would fail because it expects a permissions error. This affects some continuous integration setups. Fixes bug 23758; bugfix on 0.3.2.2-alpha.
bug fixesStop unconditionally mirroring the tor repository in GitLab CI. This prevented developers from enabling GitLab CI on master. Fixes bug 23755; bugfix on 0.3.2.2-alpha.
bug fixesFix the hidden service v3 descriptor decoding fuzzing to use the latest decoding API correctly. Fixes bug 21509; bugfix on 0.3.2.1-alpha.
Minor bug fixes (warnings):
bug fixesWhen we get an HTTP request on a SOCKS port, tell the user about the new HTTPTunnelPort option. Previously, we would give a "Tor is not an HTTP Proxy" message, which stopped being true when HTTPTunnelPort was introduced. Fixes bug 23678; bugfix on 0.3.2.1-alpha.

New in Tor 0.3.2.2 Alpha (Oct 3, 2017)

Tor 0.3.2.2-alpha is the second release in the 0.3.2 series. This release fixes several minor bugs in the new scheduler and next- generation onion services; both features were newly added in the 0.3.2 series. Other fixes in this alpha include several fixes for non-fatal tracebacks which would appear in logs.
With the aim to stabilise the 0.3.2 series by 15 December 2017, this alpha does not contain any substantial new features. Minor features include better testing and logging.
The following comprises the complete list of changes included in tor-0.3.2.2-alpha:
Major bug fixes (relay, crash, assertion failure):
Fix a timing-based assertion failure that could occur when the circuit out-of-memory handler freed a connection's output buffer. Fixes bug 23690; bugfix on 0.2.6.1-alpha.
Major bug fixes (scheduler):
If a channel is put into the scheduler's pending list, then it starts closing, and then if the scheduler runs before it finishes closing, the scheduler will get stuck trying to flush its cells while the lower layers refuse to cooperate. Fix that race condition by giving the scheduler an escape method. Fixes bug 23676; bugfix on 0.3.2.1-alpha.
Minor features (build, compilation):
The "check-changes" feature is now part of the "make check" tests; we'll use it to try to prevent misformed changes files from accumulating. Closes ticket 23564.
Tor builds should now fail if there are any mismatches between the C type representing a configuration variable and the C type the data-driven parser uses to store a value there. Previously, we needed to check these by hand, which sometimes led to mistakes. Closes ticket 23643.
Minor features (directory authorities):
Remove longclaw's IPv6 address, as it will soon change. Authority IPv6 addresses were originally added in 0.2.8.1-alpha. This leaves 3/8 directory authorities with IPv6 addresses, but there are also 52 fallback directory mirrors with IPv6 addresses. Resolves 19760.
Minor features (hidden service, circuit, logging):
Improve logging of many callsite in the circuit subsystem to print the circuit identifier(s).
Log when we cleanup an intro point from a service so we know when and for what reason it happened. Closes ticket 23604.
Minor features (logging):
Log more circuit information whenever we are about to try to package a relay cell on a circuit with a nonexistent n_chan. Attempt to diagnose ticket 8185.
Improve info-level log identification of particular circuits, to help with debugging. Closes ticket 23645.
Minor features (relay):
When choosing which circuits can be expired as unused, consider circuits from clients even if those clients used regular CREATE cells to make them; and do not consider circuits from relays even if they were made with CREATE_FAST. Part of ticket 22805.
Minor features (robustness):
Change several fatal assertions when flushing buffers into non- fatal assertions, to prevent any recurrence of 23690.
Minor features (spec conformance, bridge, diagnostic):
When handling the USERADDR command on an ExtOrPort, warn when the transports provides a USERADDR with no port. In a future version, USERADDR commands of this format may be rejected. Detects problems related to ticket 23080.
Minor features (testing):
Add a unit test to make sure that our own generated platform string will be accepted by directory authorities. Closes ticket 22109.
Minor bug fixes (bootstrapping):
When warning about state file clock skew, report the correct direction for the detected skew. Fixes bug 23606; bugfix on 0.2.8.1-alpha.
Avoid an assertion failure when logging a state file clock skew very early in bootstrapping. Fixes bug 23607; bugfix on 0.3.2.1-alpha.
Minor bug fixes (build, compilation):
Fix a compilation warning when building with zstd support on 32-bit platforms. Fixes bug 23568; bugfix on 0.3.1.1-alpha. Found and fixed by Andreas Stieger.
When searching for OpenSSL, don't accept any OpenSSL library that lacks TLSv1_1_method(): Tor doesn't build with those versions. Additionally, look in /usr/local/opt/openssl, if it's present. These changes together repair the default build on OSX systems with Homebrew installed. Fixes bug 23602; bugfix on 0.2.7.2-alpha.
Minor bug fixes (compression):
Handle a pathological case when decompressing Zstandard data when the output buffer size is zero. Fixes bug 23551; bugfix on 0.3.1.1-alpha.
Minor bug fixes (documentation):
Fix manpage to not refer to the obsolete (and misspelled) UseEntryGuardsAsDirectoryGuards parameter in the description of NumDirectoryGuards. Fixes bug 23611; bugfix on 0.2.4.8-alpha.
Minor bug fixes (hidden service v3):
Don't log an assertion failure when we can't find the right information to extend to an introduction point. In rare cases, this could happen, causing a warning, even though tor would recover gracefully. Fixes bug 23159; bugfix on 0.3.2.1-alpha.
Pad RENDEZVOUS cell up to the size of the legacy cell which is much bigger so the rendezvous point can't distinguish which hidden service protocol is being used. Fixes bug 23420; bugfix on 0.3.2.1-alpha.
Minor bug fixes (hidden service, relay):
Avoid a possible double close of a circuit by the intro point on error of sending the INTRO_ESTABLISHED cell. Fixes bug 23610; bugfix on 0.3.0.1-alpha.
Minor bug fixes (logging, relay shutdown, annoyance):
When a circuit is marked for close, do not attempt to package any cells for channels on that circuit. Previously, we would detect this condition lower in the call stack, when we noticed that the circuit had no attached channel, and log an annoying message. Fixes bug 8185; bugfix on 0.2.5.4-alpha.
Minor bug fixes (scheduler):
When switching schedulers due to a consensus change, we didn't give the new scheduler a chance to react to the consensus. Fix that. Fixes bug 23537; bugfix on 0.3.2.1-alpha.
Make the KISTSchedRunInterval option a non negative value. With this, the way to disable KIST through the consensus is to set it to 0. Fixes bug 23539; bugfix on 0.3.2.1-alpha.
Only notice log the selected scheduler when we switch scheduler types. Fixes bug 23552; bugfix on 0.3.2.1-alpha.
Avoid a compilation warning on macOS in scheduler_ev_add() caused by a different tv_usec data type. Fixes bug 23575; bugfix on 0.3.2.1-alpha.
Make a hard exit if tor is unable to pick a scheduler which can happen if the user specifies a scheduler type that is not supported and not other types in Schedulers. Fixes bug 23581; bugfix on 0.3.2.1-alpha.
Properly initialize the scheduler last run time counter so it is not 0 at the first tick. Fixes bug 23696; bugfix on 0.3.2.1-alpha.
Minor bug fixes (testing):
Capture and detect several "Result does not fit" warnings in unit tests on platforms with 32-bit time_t. Fixes bug 21800; bugfix on 0.2.9.3-alpha.
Fix additional channelpadding unit test failures by using mocked time instead of actual time for all tests. Fixes bug 23608; bugfix on 0.3.1.1-alpha.
The removal of some old scheduler options caused some tests to fail on BSD systems. Assume current behavior is correct and make the tests pass again. Fixes bug 23566; bugfix on 0.3.2.1-alpha.
Code simplification and refactoring:
Remove various ways of testing circuits and connections for "clientness"; instead, favor channel_is_client(). Part of ticket 22805.
Deprecated features:
The ReachableDirAddresses and ClientPreferIPv6DirPort options are now deprecated; they do not apply to relays, and they have had no effect on clients since 0.2.8.x. Closes ticket 19704.
Documentation:
HiddenServiceVersion man page entry wasn't mentioning the now supported version 3. Fixes ticket 23580; bugfix on 0.3.2.1-alpha.
Clarify that the Address option is entirely about setting an advertised IPv4 address. Closes ticket 18891.
Clarify the manpage's use of the term "address" to clarify what kind of address is intended. Closes ticket 21405.
Document that onion service subdomains are allowed, and ignored. Closes ticket 18736.

New in Tor 0.3.2.1 Alpha (Sep 19, 2017)

Major feature (scheduler, channel):
Tor now uses new schedulers to decide which circuits should deliver cells first, in order to improve congestion at relays. The first type is called "KIST" ("Kernel Informed Socket Transport"), and is only available on Linux-like systems: it uses feedback from the kernel to prevent the kernel's TCP buffers from growing too full. The second new scheduler type is called "KISTLite": it behaves the same as KIST, but runs on systems without kernel support for inspecting TCP implementation details. The old scheduler is still available, under the name "Vanilla". To change the default scheduler preference order, use the new "Schedulers" option. (The default preference order is "KIST,KISTLite,Vanilla".)
Matt Traudt implemented KIST, based on research by Rob Jansen, John Geddes, Christ Wacek, Micah Sherr, and Paul Syverson. For more information, see the design paper at http://www.robgjansen.com/publications/kist-sec2014.pdf and the followup implementation paper at https://arxiv.org/abs/1709.01044. Closes ticket 12541.
Major features (next-generation onion services):
Tor now supports the next-generation onion services protocol for clients and services! As part of this release, the core of proposal 224 has been implemented and is available for experimentation and testing by our users.
Major bug fixes (usability, control port):
Report trusted clock skew indications as bootstrap errors, so controllers can more easily alert users when their clocks are wrong. Fixes bug 23506; bugfix on 0.1.2.6-alpha.
Minor features (bug detection):
Log a warning message with a stack trace for any attempt to call get_options() during option validation. This pattern has caused subtle bugs in the past. Closes ticket 22281.
Minor features (client):
You can now use Tor as a tunneled HTTP proxy: use the new HTTPTunnelPort option to open a port that accepts HTTP CONNECT requests. Closes ticket 22407.
Add an extra check to make sure that we always use the newer guard selection code for picking our guards. Closes ticket 22779.
When downloading (micro)descriptors, don't split the list into multiple requests unless we want at least 32 descriptors. Previously, we split at 4, not 32, which led to significant overhead in HTTP request size and degradation in compression performance. Closes ticket 23220.
Minor features (command line):
Add a new commandline option, --key-expiration, which prints when the current signing key is going to expire. Implements ticket 17639; patch by Isis Lovecruft.
Minor features (control port):
If an application tries to use the control port as an HTTP proxy, respond with a meaningful "This is the Tor control port" message, and log the event. Closes ticket 1667. Patch from Ravi Chandra Padmala.
Provide better error message for GETINFO desc/(id|name) when not fetching router descriptors. Closes ticket 5847. Patch by Kevin Butler.
Add GETINFO "{desc,md}/download-enabled", to inform the controller whether Tor will try to download router descriptors and microdescriptors respectively. Closes ticket 22684.
Added new GETINFO targets "ip-to-country/{ipv4,ipv6}-available", so controllers can tell whether the geoip databases are loaded. Closes ticket 23237.
Adds a timestamp field to the CIRC_BW and STREAM_BW bandwidth events. Closes ticket 19254. Patch by "DonnchaC".
Minor features (development support):
Developers can now generate a call-graph for Tor using the "calltool" python program, which post-processes object dumps. It should work okay on many Linux and OSX platforms, and might work elsewhere too. To run it, install calltool from https://gitweb.torproject.org/user/nickm/calltool.git and run "make callgraph". Closes ticket 19307.
Minor features (ed25519):
Add validation function to checks for torsion components in ed25519 public keys, used by prop224 client-side code. Closes ticket 22006. Math help by Ian Goldberg.
Minor features (exit relay, DNS):
Improve the clarity and safety of the log message from evdns when receiving an apparently spoofed DNS reply. Closes ticket 3056.
Minor features (integration, hardening):
Add a new NoExec option to prevent Tor from running other programs. When this option is set to 1, Tor will never try to run another program, regardless of the settings of PortForwardingHelper, ClientTransportPlugin, or ServerTransportPlugin. Once NoExec is set, it cannot be disabled without restarting Tor. Closes ticket 22976.
Minor features (logging):
Improve the warning message for specifying a relay by nickname. The previous message implied that nickname registration was still part of the Tor network design, which it isn't. Closes ticket 20488.
If the sandbox filter fails to load, suggest to the user that their kernel might not support seccomp2. Closes ticket 23090.
Minor features (portability):
Check at configure time whether uint8_t is the same type as unsigned char. Lots of existing code already makes this assumption, and there could be strict aliasing issues if the assumption is violated. Closes ticket 22410.
Minor features (relay, configuration):
Reject attempts to use relative file paths when RunAsDaemon is set. Previously, Tor would accept these, but the directory- changing step of RunAsDaemon would give strange and/or confusing results. Closes ticket 22731.
Minor features (startup, safety):
When configured to write a PID file, Tor now exits if it is unable to do so. Previously, it would warn and continue. Closes ticket 20119.
Minor features (static analysis):
The BUG() macro has been changed slightly so that Coverity no longer complains about dead code if the bug is impossible. Closes ticket 23054.
Minor features (testing):
The default chutney network tests now include tests for the v3 hidden service design. Make sure you have the latest version of chutney if you want to run these. Closes ticket 22437.
Add a unit test to verify that we can parse a hardcoded v2 hidden service descriptor. Closes ticket 15554.
Minor bug fixes (certificate handling):
Fix a time handling bug in Tor certificates set to expire after the year 2106. Fixes bug 23055; bugfix on 0.3.0.1-alpha. Found by Coverity as CID 1415728.
Minor bug fixes (client, usability):
Refrain from needlessly rejecting SOCKS5-with-hostnames and SOCKS4a requests that contain IP address strings, even when SafeSocks in enabled, as this prevents user from connecting to known IP addresses without relying on DNS for resolving. SafeSocks still rejects SOCKS connections that connect to IP addresses when those addresses are _not_ encoded as hostnames. Fixes bug 22461; bugfix on Tor 0.2.6.2-alpha.
Minor bug fixes (code correctness):
Call htons() in extend_cell_format() for encoding a 16-bit value. Previously we used ntohs(), which happens to behave the same on all the platforms we support, but which isn't really correct. Fixes bug 23106; bugfix on 0.2.4.8-alpha.
For defense-in-depth, make the controller's write_escaped_data() function robust to extremely long inputs. Fixes bug 19281; bugfix on 0.1.1.1-alpha. Reported by Guido Vranken.
Minor bug fixes (compilation):
Fix unused-variable warnings in donna's Curve25519 SSE2 code. Fixes bug 22895; bugfix on 0.2.7.2-alpha.
Minor bug fixes (consensus expiry):
Check for adequate directory information correctly. Previously, Tor would reconsider whether it had sufficient directory information every 2 minutes. Fixes bug 23091; bugfix on 0.2.0.19-alpha.
Minor bug fixes (directory protocol):
Directory servers now include a "Date:" http header for response codes other than 200. Clients starting with a skewed clock and a recent consensus were getting "304 Not modified" responses from directory authorities, so without the Date header, the client would never hear about a wrong clock. Fixes bug 23499; bugfix on 0.0.8rc1.
Make clients wait for 6 seconds before trying to download a consensus from an authority. Fixes bug 17750; bugfix on 0.2.8.1-alpha.
Minor bug fixes (DoS-resistance):
If future code asks if there are any running bridges, without checking if bridges are enabled, log a BUG warning rather than crashing. Fixes bug 23524; bugfix on 0.3.0.1-alpha.
Minor bug fixes (format strictness):
Restrict several data formats to decimal. Previously, the BuildTimeHistogram entries in the state file, the "bw=" entries in the bandwidth authority file, and the process IDs passed to the __OwningControllerProcess option could all be specified in hex or octal as well as in decimal. This was not an intentional feature. Fixes bug 22802; bug fixes on 0.2.2.1-alpha, 0.2.2.2-alpha, and 0.2.2.28-beta.
Minor bug fixes (heartbeat):
If we fail to write a heartbeat message, schedule a retry for the minimum heartbeat interval number of seconds in the future. Fixes bug 19476; bugfix on 0.2.3.1-alpha.
Minor bug fixes (linux seccomp2 sandbox, logging):
Fix some messages on unexpected errors from the seccomp2 library. Fixes bug 22750; bugfix on 0.2.5.1-alpha. Patch from "cypherpunks".
Minor bug fixes (logging):
Remove duplicate log messages regarding opening non-local SocksPorts upon parsing config and opening listeners at startup. Fixes bug 4019; bugfix on 0.2.3.3-alpha.
Use a more comprehensible log message when telling the user they've excluded every running exit node. Fixes bug 7890; bugfix on 0.2.2.25-alpha.
When logging the number of descriptors we intend to download per directory request, do not log a number higher than then the number of descriptors we're fetching in total. Fixes bug 19648; bugfix on 0.1.1.8-alpha.
When warning about a directory owned by the wrong user, log the actual name of the user owning the directory. Previously, we'd log the name of the process owner twice. Fixes bug 23487; bugfix on 0.2.9.1-alpha.
The tor specification says hop counts are 1-based, so fix two log messages that mistakenly logged 0-based hop counts. Fixes bug 18982; bugfix on 0.2.6.2-alpha and 0.2.4.5-alpha. Patch by teor. Credit to Xiaofan Li for reporting this issue.
Minor bug fixes (portability):
Stop using the PATH_MAX variable, which is not defined on GNU Hurd. Fixes bug 23098; bugfix on 0.3.1.1-alpha.
Minor bug fixes (relay):
When uploading our descriptor for the first time after startup, report the reason for uploading as "Tor just started" rather than leaving it blank. Fixes bug 22885; bugfix on 0.2.3.4-alpha.
Avoid unnecessary calls to directory_fetches_from_authorities() on relays, to prevent spurious address resolutions and descriptor rebuilds. This is a mitigation for bug 21789. Fixes bug 23470; bugfix on in 0.2.8.1-alpha.
Minor bug fixes (tests):
Fix a broken unit test for the OutboundAddress option: the parsing function was never returning an error on failure. Fixes bug 23366; bugfix on 0.3.0.3-alpha.
Fix a signed-integer overflow in the unit tests for dir/download_status_random_backoff, which was untriggered until we fixed bug 17750. Fixes bug 22924; bugfix on 0.2.9.1-alpha.
Minor bug fixes (usability, control port):
Stop making an unnecessary routerlist check in NETINFO clock skew detection; this was preventing clients from reporting NETINFO clock skew to controllers. Fixes bug 23532; bugfix on 0.2.4.4-alpha.
Code simplification and refactoring:
Extract the code for handling newly-open channels into a separate function from the general code to handle channel state transitions. This change simplifies our callgraph, reducing the size of the largest strongly connected component by roughly a factor of two. Closes ticket 22608.
Remove dead code for largely unused statistics on the number of times we've attempted various public key operations. Fixes bug 19871; bugfix on 0.1.2.4-alpha. Fix by Isis Lovecruft.
Remove several now-obsolete functions for asking about old variants directory authority status. Closes ticket 22311; patch from "huyvq".
Remove some of the code that once supported "Named" and "Unnamed" routers. Authorities no longer vote for these flags. Closes ticket 22215.
Rename the obsolete malleable hybrid_encrypt functions used in TAP and old hidden services, to indicate that they aren't suitable for new protocols or formats. Closes ticket 23026.
Replace our STRUCT_OFFSET() macro with offsetof(). Closes ticket 22521. Patch from Neel Chauhan.
Split the enormous circuit_send_next_onion_skin() function into multiple subfunctions. Closes ticket 22804.
Split the portions of the buffer.c module that handle particular protocols into separate modules. Part of ticket 23149.
Use our test macros more consistently, to produce more useful error messages when our unit tests fail. Add coccinelle patches to allow us to re-check for test macro uses. Closes ticket 22497.
Deprecated features:
Deprecate HTTPProxy/HTTPProxyAuthenticator config options. They only applies to direct unencrypted HTTP connections to your directory server, which your Tor probably isn't using. Closes ticket 20575.
Documentation:
Clarify in the manual that "Sandbox 1" is only supported on Linux kernels. Closes ticket 22677.
Document all values of PublishServerDescriptor in the manpage. Closes ticket 15645.
Improve the documentation for the directory port part of the DirAuthority line. Closes ticket 20152.
Restore documentation for the authorities' "approved-routers" file. Closes ticket 21148.
Removed features:
The AllowDotExit option has been removed as unsafe. It has been deprecated since 0.2.9.2-alpha. Closes ticket 23426.
The ClientDNSRejectInternalAddresses flag can no longer be set on non-testing networks. It has been deprecated since 0.2.9.2-alpha. Closes ticket 21031.
The controller API no longer includes an AUTHDIR_NEWDESCS event: nobody was using it any longer. Closes ticket 22377.

New in Tor 0.3.1.7 (Sep 18, 2017)

New dependencies:
To build with zstd and lzma support, Tor now requires the pkg-config tool at build time.
Major bugfixes (security, onion services, loggging):
Fix a bug where we could log uninitialized stack when a certain onion service error occurred while SafeLogging was disabled. Fixes bug #23490; bugfix on 0.2.7.2-alpha. This is also tracked as TROVE-2017-008 and CVE-2017-0380.
Major features (build system, continuous integration):
Tor's repository now includes a Travis Continuous Integration (CI) configuration file (.travis.yml). This is meant to help new developers and contributors who fork Tor to a Github repository be better able to test their changes, and understand what we expect to pass. To use this new build feature, you must fork Tor to your Github account, then go into the "Integrations" menu in the repository settings for your fork and enable Travis, then push your changes. Closes ticket 22636.
Major features (directory protocol):
Tor relays and authorities can now serve clients an abbreviated version of the consensus document, containing only the changes since an older consensus document that the client holds. Clients now request these documents when available. When both client and server use this new protocol, they will use far less bandwidth (up to 94% less) to keep the client's consensus up-to-date. Implements proposal 140; closes ticket 13339. Based on work by Daniel Martí.
Tor can now compress directory traffic with lzma or with zstd compression algorithms, which can deliver better bandwidth performance. Because lzma is computationally expensive, it's only used for documents that can be compressed once and served many times. Support for these algorithms requires that tor is built with the libzstd and/or liblzma libraries available. Implements proposal 278; closes ticket 21662.
Relays now perform the more expensive compression operations, and consensus diff generation, in worker threads. This separation avoids delaying the main thread when a new consensus arrives.
Major features (experimental):
Tor can now build modules written in Rust. To turn this on, pass the "--enable-rust" flag to the configure script. It's not time to get excited yet: currently, there is no actual Rust functionality beyond some simple glue code, and a notice at startup to tell you that Rust is running. Still, we hope that programmers and packagers will try building Tor with Rust support, so that we can find issues and solve portability problems. Closes ticket 22106.
Major features (traffic analysis resistance):
Connections between clients and relays now send a padding cell in each direction every 1.5 to 9.5 seconds (tunable via consensus parameters). This padding will not resist specialized eavesdroppers, but it should be enough to make many ISPs' routine network flow logging less useful in traffic analysis against Tor users.
Padding is negotiated using Tor's link protocol, so both relays and clients must upgrade for this to take effect. Clients may still send padding despite the relay's version by setting ConnectionPadding 1 in torrc, and may disable padding by setting ConnectionPadding 0 in torrc. Padding may be minimized for mobile users with the torrc option ReducedConnectionPadding. Implements Proposal 251 and Section 2 of Proposal 254; closes ticket 16861.
Relays will publish 24 hour totals of padding and non-padding cell counts to their extra-info descriptors, unless PaddingStatistics 0 is set in torrc. These 24 hour totals are also rounded to multiples of 10000.
Major bugfixes (onion service, relay, security):
Fix a remotely triggerable assertion failure when a onion service handles a malformed BEGIN cell. Fixes bug 22493, tracked as TROVE-2017-004 and as CVE-2017-0375; bugfix on 0.3.0.1-alpha.
Fix a remotely triggerable assertion failure caused by receiving a BEGIN_DIR cell on a onion service rendezvous circuit. Fixes bug 22494, tracked as TROVE-2017-005 and CVE-2017-0376; bugfix on 0.2.2.1-alpha.
Major bugfixes (path selection, security):
When choosing which guard to use for a circuit, avoid the exit's family along with the exit itself. Previously, the new guard selection logic avoided the exit, but did not consider its family. Fixes bug 22753; bugfix on 0.3.0.1-alpha. Tracked as TROVE-2017- 006 and CVE-2017-0377.
Major bugfixes (connection usage):
We use NETINFO cells to try to determine if both relays involved in a connection will agree on the canonical status of that connection. We prefer the connections where this is the case for extend cells, and try to close connections where relays disagree on their canonical status early. Also, we now prefer the oldest valid connection for extend cells. These two changes should reduce the number of long-term connections that are kept open between relays. Fixes bug 17604; bugfix on 0.2.5.5-alpha.
Relays now log hourly statistics (look for "channel_check_for_duplicates" lines) on the total number of connections to other relays. If the number of connections per relay is unexpectedly large, this log message is at notice level. Otherwise it is at info.
Major bugfixes (entry guards):
When starting with an old consensus, do not add new entry guards unless the consensus is "reasonably live" (under 1 day old). Fixes one root cause of bug 22400; bugfix on 0.3.0.1-alpha.
Don't block bootstrapping when a primary bridge is offline and we can't get its descriptor. Fixes bug 22325; fixes one case of bug 21969; bugfix on 0.3.0.3-alpha.
Major bugfixes (linux TPROXY support):
Fix a typo that had prevented TPROXY-based transparent proxying from working under Linux. Fixes bug 18100; bugfix on 0.2.6.3-alpha. Patch from "d4fq0fQAgoJ".
Major bugfixes (openbsd, denial-of-service):
Avoid an assertion failure bug affecting our implementation of inet_pton(AF_INET6) on certain OpenBSD systems whose strtol() handling of "0xx" differs from what we had expected. Fixes bug 22789; bugfix on 0.2.3.8-alpha. Also tracked as TROVE-2017-007.
Major bugfixes (relay, link handshake):
When performing the v3 link handshake on a TLS connection, report that we have the x509 certificate that we actually used on that connection, even if we have changed certificates since that connection was first opened. Previously, we would claim to have used our most recent x509 link certificate, which would sometimes make the link handshake fail. Fixes one case of bug 22460; bugfix on 0.2.3.6-alpha.
Major bugfixes (relays, key management):
Regenerate link and authentication certificates whenever the key that signs them changes; also, regenerate link certificates whenever the signed key changes. Previously, these processes were only weakly coupled, and we relays could (for minutes to hours) wind up with an inconsistent set of keys and certificates, which other relays would not accept. Fixes two cases of bug 22460; bugfix on 0.3.0.1-alpha.
When sending an Ed25519 signing->link certificate in a CERTS cell, send the certificate that matches the x509 certificate that we used on the TLS connection. Previously, there was a race condition if the TLS context rotated after we began the TLS handshake but before we sent the CERTS cell. Fixes a case of bug 22460; bugfix on 0.3.0.1-alpha.
Minor features (security, windows):
Enable a couple of pieces of Windows hardening: one (HeapEnableTerminationOnCorruption) that has been on-by-default since Windows 8, and unavailable before Windows 7; and one (PROCESS_DEP_DISABLE_ATL_THUNK_EMULATION) which we believe doesn't affect us, but shouldn't do any harm. Closes ticket 21953.
Minor features (bridge authority):
Add "fingerprint" lines to the networkstatus-bridges file produced by bridge authorities. Closes ticket 22207.
Minor features (code style):
Add "Falls through" comments to our codebase, in order to silence GCC 7's -Wimplicit-fallthrough warnings. Patch from Andreas Stieger. Closes ticket 22446.
Minor features (config options):
Allow "%include" directives in torrc configuration files. These directives import the settings from other files, or from all the files in a directory. Closes ticket 1922. Code by Daniel Pinto.
Make SAVECONF return an error when overwriting a torrc that has includes. Using SAVECONF with the FORCE option will allow it to overwrite torrc even if includes are used. Related to ticket 1922.
Add "GETINFO config-can-saveconf" to tell controllers if SAVECONF will work without the FORCE option. Related to ticket 1922.
Minor features (controller):
Warn the first time that a controller requests data in the long- deprecated 'GETINFO network-status' format. Closes ticket 21703.
Minor features (defaults):
The default value for UseCreateFast is now 0: clients which haven't yet received a consensus document will now use a proper ntor handshake to talk to their directory servers whenever they can. Closes ticket 21407.
Onion key rotation and expiry intervals are now defined as a network consensus parameter, per proposal 274. The default lifetime of an onion key is increased from 7 to 28 days. Old onion keys will expire after 7 days by default. This change will make consensus diffs much smaller, and save significant bandwidth. Closes ticket 21641.
Minor features (defensive programming):
Create a pair of consensus parameters, nf_pad_tor2web and nf_pad_single_onion, to disable netflow padding in the consensus for non-anonymous connections in case the overhead is high. Closes ticket 17857.
Minor features (diagnostic):
Add a stack trace to the bug warnings that can be logged when trying to send an outgoing relay cell with n_chan == 0. Diagnostic attempt for bug 23105.
Add logging messages to try to diagnose a rare bug that seems to generate RSA->Ed25519 cross-certificates dated in the 1970s. We think this is happening because of incorrect system clocks, but we'd like to know for certain. Diagnostic for bug 22466.
Avoid an assertion failure, and log a better error message, when unable to remove a file from the consensus cache on Windows. Attempts to mitigate and diagnose bug 22752.
Minor features (directory authority):
Improve the message that authorities report to relays that present RSA/Ed25519 keypairs that conflict with previously pinned keys. Closes ticket 22348.
Minor features (directory cache, consensus diff):
Add a new MaxConsensusAgeForDiffs option to allow directory cache operators with low-resource environments to adjust the number of consensuses they'll store and generate diffs from. Most cache operators should leave it unchanged. Helps to work around bug 22883.
Minor features (fallback directory list):
Update the fallback directory mirror whitelist and blacklist based on operator emails. Closes task 21121.
Replace the 177 fallbacks originally introduced in Tor 0.2.9.8 in December 2016 (of which ~126 were still functional) with a list of 151 fallbacks (32 new, 119 unchanged, 58 removed) generated in May 2017. Resolves ticket 21564.
Minor features (geoip):
Update geoip and geoip6 to the September 6 2017 Maxmind GeoLite2 Country database.
Minor features (onion services, logging):
Log a message when an onion service descriptor has fewer introduction points than specified in HiddenServiceNumIntroductionPoints. Closes tickets 21598.
Log a message when an onion service reaches its introduction point circuit limit, and when that limit is reset. Follow up to ticket 21594; closes ticket 21622.
Warn user if multiple entries in EntryNodes and at least one HiddenService are used together. Pinning EntryNodes along with an onion service can be possibly harmful; for instance see ticket 14917 or 21155. Closes ticket 21155.
Minor features (linux seccomp2 sandbox):
We now have a document storage backend compatible with the Linux seccomp2 sandbox. This backend is used for consensus documents and diffs between them; in the long term, we'd like to use it for unparseable directory material too. Closes ticket 21645
Increase the maximum allowed size passed to mprotect(PROT_WRITE) from 1MB to 16MB. This was necessary with the glibc allocator in order to allow worker threads to allocate more memory -- which in turn is necessary because of our new use of worker threads for compression. Closes ticket 22096.
Minor features (logging):
Log files are no longer created world-readable by default. (Previously, most distributors would store the logs in a non- world-readable location to prevent inappropriate access. This change is an extra precaution.) Closes ticket 21729; patch from toralf.
Minor features (performance):
Our Keccak (SHA-3) implementation now accesses memory more efficiently, especially on little-endian systems. Closes ticket 21737.
Add an O(1) implementation of channel_find_by_global_id(), to speed some controller functions.
Minor features (relay, configuration):
The MyFamily option may now be repeated as many times as desired, for relays that want to configure large families. Closes ticket 4998; patch by Daniel Pinto.
Minor features (relay, performance):
Always start relays with at least two worker threads, to prevent priority inversion on slow tasks. Part of the fix for bug 22883.
Allow background work to be queued with different priorities, so that a big pile of slow low-priority jobs will not starve out higher priority jobs. This lays the groundwork for a fix for bug 22883.
Minor features (safety):
Add an explicit check to extrainfo_parse_entry_from_string() for NULL inputs. We don't believe this can actually happen, but it may help silence a warning from the Clang analyzer. Closes ticket 21496.
Minor features (testing):
Add more tests for compression backend initialization. Closes ticket 22286.
Add a "--disable-memory-sentinels" feature to help with fuzzing. When Tor is compiled with this option, we disable a number of redundant memory-safety failsafes that are intended to stop bugs from becoming security issues. This makes it easier to hunt for bugs that would be security issues without the failsafes turned on. Closes ticket 21439.
Add a general event-tracing instrumentation support to Tor. This subsystem will enable developers and researchers to add fine- grained instrumentation to their Tor instances, for use when examining Tor network performance issues. There are no trace events yet, and event-tracing is off by default unless enabled at compile time. Implements ticket 13802.
Improve our version parsing tests: add tests for typical version components, add tests for invalid versions, including numeric range and non-numeric prefixes. Unit tests 21278, 21450, and 21507. Partially implements 21470.
Minor bugfixes (bandwidth accounting):
Roll over monthly accounting at the configured hour and minute, rather than always at 00:00. Fixes bug 22245; bugfix on 0.0.9rc1. Found by Andrey Karpov with PVS-Studio.
Minor bugfixes (code correctness):
Accurately identify client connections by their lack of peer authentication. This means that we bail out earlier if asked to extend to a client. Follow-up to 21407. Fixes bug 21406; bugfix on 0.2.4.23.
Minor bugfixes (compilation warnings):
Suppress -Wdouble-promotion warnings with clang 4.0. Fixes bug 22915; bugfix on 0.2.8.1-alpha.
Fix warnings when building with libscrypt and openssl scrypt support on Clang. Fixes bug 22916; bugfix on 0.2.7.2-alpha.
When building with certain versions of the mingw C header files, avoid float-conversion warnings when calling the C functions isfinite(), isnan(), and signbit(). Fixes bug 22801; bugfix on 0.2.8.1-alpha.
Minor bugfixes (compilation):
Avoid compiler warnings in the unit tests for calling tor_sscanf() with wide string outputs. Fixes bug 15582; bugfix on 0.2.6.2-alpha.
Minor bugfixes (compression):
When spooling compressed data to an output buffer, don't try to spool more data when there is no more data to spool and we are not trying to flush the input. Previously, we would sometimes launch compression requests with nothing to do, which interferes with our 22672 checks. Fixes bug 22719; bugfix on 0.2.0.16-alpha.
Minor bugfixes (configuration):
Do not crash when starting with LearnCircuitBuildTimeout 0. Fixes bug 22252; bugfix on 0.2.9.3-alpha.
Minor bugfixes (connection lifespan):
Allow more control over how long TLS connections are kept open: unify CircuitIdleTimeout and PredictedPortsRelevanceTime into a single option called CircuitsAvailableTimeout. Also, allow the consensus to control the default values for both this preference and the lifespan of relay-to-relay connections. Fixes bug 17592; bugfix on 0.2.5.5-alpha.
Increase the initial circuit build timeout testing frequency, to help ensure that ReducedConnectionPadding clients finish learning a timeout before their orconn would expire. The initial testing rate was set back in the days of TAP and before the Tor Browser updater, when we had to be much more careful about new clients making lots of circuits. With this change, a circuit build timeout is learned in about 15-20 minutes, instead of 100-120 minutes.
Minor bugfixes (controller):
Do not crash when receiving a HSPOST command with an empty body. Fixes part of bug 22644; bugfix on 0.2.7.1-alpha.
Do not crash when receiving a POSTDESCRIPTOR command with an empty body. Fixes part of bug 22644; bugfix on 0.2.0.1-alpha.
GETINFO onions/current and onions/detached no longer respond with 551 on empty lists. Fixes bug 21329; bugfix on 0.2.7.1-alpha.
Trigger HS descriptor events on the control port when the client fails to pick an onion service directory for an onion service. This can happen if all the hidden service directories are in ExcludeNodes, or they have all been queried within the last 15 minutes. Fixes bug 22042; bugfix on 0.2.5.2-alpha.
Minor bugfixes (correctness):
Avoid undefined behavior when parsing IPv6 entries from the geoip6 file. Fixes bug 22490; bugfix on 0.2.4.6-alpha.
Minor bugfixes (coverity build support):
Avoid Coverity build warnings related to our BUG() macro. By default, Coverity treats BUG() as the Linux kernel does: an instant abort(). We need to override that so our BUG() macro doesn't prevent Coverity from analyzing functions that use it. Fixes bug 23030; bugfix on 0.2.9.1-alpha.
Minor bugfixes (defensive programming):
Detect and break out of infinite loops in our compression code. We don't think that any such loops exist now, but it's best to be safe. Closes ticket 22672.
Fix a memset() off the end of an array when packing cells. This bug should be harmless in practice, since the corrupted bytes are still in the same structure, and are always padding bytes, ignored, or immediately overwritten, depending on compiler behavior. Nevertheless, because the memset()'s purpose is to make sure that any other cell-handling bugs can't expose bytes to the network, we need to fix it. Fixes bug 22737; bugfix on 0.2.4.11-alpha. Fixes CID 1401591.
Minor bugfixes (directory authority):
When a directory authority rejects a descriptor or extrainfo with a given digest, mark that digest as undownloadable, so that we do not attempt to download it again over and over. We previously tried to avoid downloading such descriptors by other means, but we didn't notice if we accidentally downloaded one anyway. This behavior became problematic in 0.2.7.2-alpha, when authorities began pinning Ed25519 keys. Fixes bug 22349; bugfix on 0.2.1.19-alpha.
When rejecting a router descriptor for running an obsolete version of Tor without ntor support, warn about the obsolete tor version, not the missing ntor key. Fixes bug 20270; bugfix on 0.2.9.3-alpha.
Prevent the shared randomness subsystem from asserting when initialized by a bridge authority with an incomplete configuration file. Fixes bug 21586; bugfix on 0.2.9.8.
Minor bugfixes (error reporting, windows):
When formatting Windows error messages, use the English format to avoid codepage issues. Fixes bug 22520; bugfix on 0.1.2.8-alpha. Patch from "Vort".
Minor bugfixes (exit-side DNS):
Fix an untriggerable assertion that checked the output of a libevent DNS error, so that the assertion actually behaves as expected. Fixes bug 22244; bugfix on 0.2.0.20-rc. Found by Andrey Karpov using PVS-Studio.
Minor bugfixes (fallback directories):
Make the usage example in updateFallbackDirs.py actually work, and explain what it does. Fixes bug 22270; bugfix on 0.3.0.3-alpha.
Decrease the guard flag average required to be a fallback. This allows us to keep relays that have their guard flag removed when they restart. Fixes bug 20913; bugfix on 0.2.8.1-alpha.
Decrease the minimum number of fallbacks to 100. Fixes bug 20913; bugfix on 0.2.8.1-alpha.
Make sure fallback directory mirrors have the same address, port, and relay identity key for at least 30 days before they are selected. Fixes bug 20913; bugfix on 0.2.8.1-alpha.
Minor bugfixes (file limits, osx):
When setting the maximum number of connections allowed by the OS, always allow some extra file descriptors for other files. Fixes bug 22797; bugfix on 0.2.0.10-alpha.
Minor bugfixes (onion services):
Increase the number of circuits that a service is allowed to open over a specific period of time. The value was lower than it should be (8 vs 12) in the normal case of 3 introduction points. Fixes bug 22159; bugfix on 0.3.0.5-rc.
Fix a BUG warning during HSv3 descriptor decoding that could be cause by a specially crafted descriptor. Fixes bug 23233; bugfix on 0.3.0.1-alpha. Bug found by "haxxpop".
Stop printing a cryptic warning when an onion service gets a request to connect to a virtual port that it hasn't configured. Fixes bug 16706; bugfix on 0.2.6.3-alpha.
Simplify onion service descriptor creation by using an existing flag to check if an introduction point is established. Fixes bug 21599; bugfix on 0.2.7.2-alpha.
Minor bugfixes (link handshake):
Lower the lifetime of the RSA->Ed25519 cross-certificate to six months, and regenerate it when it is within one month of expiring. Previously, we had generated this certificate at startup with a ten-year lifetime, but that could lead to weird behavior when Tor was started with a grossly inaccurate clock. Mitigates bug 22466; mitigation on 0.3.0.1-alpha.
Minor bugfixes (linux seccomp2 sandbox):
Avoid a sandbox failure when trying to re-bind to a socket and mark it as IPv6-only. Fixes bug 20247; bugfix on 0.2.5.1-alpha.
Permit the fchmod system call, to avoid crashing on startup when starting with the seccomp2 sandbox and an unexpected set of permissions on the data directory or its contents. Fixes bug 22516; bugfix on 0.2.5.4-alpha.
Minor bugfixes (logging):
When decompressing, do not warn if we fail to decompress using a compression method that we merely guessed. Fixes part of bug 22670; bugfix on 0.1.1.14-alpha.
When decompressing, treat mismatch between content-encoding and actual compression type as a protocol warning. Fixes part of bug 22670; bugfix on 0.1.1.9-alpha.
Downgrade "assigned_to_cpuworker failed" message to info-level severity. In every case that can reach it, either a better warning has already been logged, or no warning is warranted. Fixes bug 22356; bugfix on 0.2.6.3-alpha.
Log a better message when a directory authority replies to an upload with an unexpected status code. Fixes bug 11121; bugfix on 0.1.0.1-rc.
Downgrade a log statement about unexpected relay cells from "bug" to "protocol warning", because there is at least one use case where it can be triggered by a buggy tor implementation. Fixes bug 21293; bugfix on 0.1.1.14-alpha.
Minor bugfixes (logging, relay):
Remove a forgotten debugging message when an introduction point successfully establishes an onion service prop224 circuit with a client.
Change three other log_warn() for an introduction point to protocol warnings, because they can be failure from the network and are not relevant to the operator. Fixes bug 23078; bugfix on 0.3.0.1-alpha and 0.3.0.2-alpha.
Minor bugfixes (relay):
Inform the geoip and rephist modules about all requests, even on relays that are only fetching microdescriptors. Fixes a bug related to 21585; bugfix on 0.3.0.1-alpha.
Minor bugfixes (memory leaks):
Fix a small memory leak at exit from the backtrace handler code. Fixes bug 21788; bugfix on 0.2.5.2-alpha. Patch from Daniel Pinto.
When directory authorities reject a router descriptor due to keypinning, free the router descriptor rather than leaking the memory. Fixes bug 22370; bugfix on 0.2.7.2-alpha.
Fix a small memory leak when validating a configuration that uses two or more AF_UNIX sockets for the same port type. Fixes bug 23053; bugfix on 0.2.6.3-alpha. This is CID 1415725.
Minor bugfixes (process behavior):
When exiting because of an error, always exit with a nonzero exit status. Previously, we would fail to report an error in our exit status in cases related to __OwningControllerProcess failure, lockfile contention, and Ed25519 key initialization. Fixes bug 22720; bugfix on versions 0.2.1.6-alpha, 0.2.2.28-beta, and 0.2.7.2-alpha respectively. Reported by "f55jwk4f"; patch from "huyvq".
Minor bugfixes (robustness, error handling):
Improve our handling of the cases where OpenSSL encounters a memory error while encoding keys and certificates. We haven't observed these errors in the wild, but if they do happen, we now detect and respond better. Fixes bug 19418; bugfix on all versions of Tor. Reported by Guido Vranken.
Minor bugfixes (testing):
Fix an undersized buffer in test-memwipe.c. Fixes bug 23291; bugfix on 0.2.7.2-alpha. Found and patched by Ties Stuij.
Use unbuffered I/O for utility functions around the process_handle_t type. This fixes unit test failures reported on OpenBSD and FreeBSD. Fixes bug 21654; bugfix on 0.2.3.1-alpha.
Make display of captured unit test log messages consistent. Fixes bug 21510; bugfix on 0.2.9.3-alpha.
Make test-network.sh always call chutney's test-network.sh. Previously, this only worked on systems which had bash installed, due to some bash-specific code in the script. Fixes bug 19699; bugfix on 0.3.0.4-rc. Follow-up to ticket 21581.
Fix a memory leak in the link-handshake/certs_ok_ed25519 test. Fixes bug 22803; bugfix on 0.3.0.1-alpha.
The unit tests now pass on systems where localhost is misconfigured to some IPv4 address other than 127.0.0.1. Fixes bug 6298; bugfix on 0.0.9pre2.
Minor bugfixes (voting consistency):
Reject version numbers with non-numeric prefixes (such as +, -, or whitespace). Disallowing whitespace prevents differential version parsing between POSIX-based and Windows platforms. Fixes bug 21507 and part of 21508; bugfix on 0.0.8pre1.
Minor bugfixes (Windows service):
When running as a Windows service, set the ID of the main thread correctly. Failure to do so made us fail to send log messages to the controller in 0.2.1.16-rc, slowed down controller event delivery in 0.2.7.3-rc and later, and crash with an assertion failure in 0.3.1.1-alpha. Fixes bug 23081; bugfix on 0.2.1.6-alpha. Patch and diagnosis from "Vort".
Minor bugfixes (windows, relay):
Resolve "Failure from drain_fd: No error" warnings on Windows relays. Fixes bug 21540; bugfix on 0.2.6.3-alpha.
Code simplification and refactoring:
Break up the 630-line function connection_dir_client_reached_eof() into a dozen smaller functions. This change should help maintainability and readability of the client directory code.
Isolate our use of the openssl headers so that they are only included from our crypto wrapper modules, and from tests that examine those modules' internals. Closes ticket 21841.
Simplify our API to launch directory requests, making it more extensible and less error-prone. Now it's easier to add extra headers to directory requests. Closes ticket 21646.
Our base64 decoding functions no longer overestimate the output space that they need when parsing unpadded inputs. Closes ticket 17868.
Remove unused "ROUTER_ADDED_NOTIFY_GENERATOR" internal value. Resolves ticket 22213.
The logic that directory caches use to spool request to clients, serving them one part at a time so as not to allocate too much memory, has been refactored for consistency. Previously there was a separate spooling implementation per type of spoolable data. Now there is one common spooling implementation, with extensible data types. Closes ticket 21651.
Tor's compression module now supports multiple backends. Part of the implementation for proposal 278; closes ticket 21663.
Documentation:
Add a manpage description for the key-pinning-journal file. Closes ticket 22347.
Correctly note that bandwidth accounting values are stored in the state file, and the bw_accounting file is now obsolete. Closes ticket 16082.
Document more of the files in the Tor data directory, including cached-extrainfo, secret_onion_key{,_ntor}.old, hidserv-stats, approved-routers, sr-random, and diff-cache. Found while fixing ticket 22347.
Clarify the manpage for the (deprecated) torify script. Closes ticket 6892.
Clarify the behavior of the KeepAliveIsolateSOCKSAuth sub-option. Closes ticket 21873.
Correct documentation about the default DataDirectory value. Closes ticket 21151.
Document the default behavior of NumEntryGuards and NumDirectoryGuards correctly. Fixes bug 21715; bugfix on 0.3.0.1-alpha.
Document key=value pluggable transport arguments for Bridge lines in torrc. Fixes bug 20341; bugfix on 0.2.5.1-alpha.
Note that bandwidth-limiting options don't affect TCP headers or DNS. Closes ticket 17170.
Removed features (configuration options, all in ticket 22060):
These configuration options are now marked Obsolete, and no longer have any effect: AllowInvalidNodes, AllowSingleHopCircuits, AllowSingleHopExits, ExcludeSingleHopRelays, FastFirstHopPK, TLSECGroup, WarnUnsafeSocks. They were first marked as deprecated in 0.2.9.2-alpha and have now been removed. The previous default behavior is now always chosen; the previous (less secure) non- default behavior is now unavailable.
CloseHSClientCircuitsImmediatelyOnTimeout and CloseHSServiceRendCircuitsImmediatelyOnTimeout were deprecated in 0.2.9.2-alpha and now have been removed. HS circuits never close on circuit build timeout; they have a longer timeout period.
{Control,DNS,Dir,Socks,Trans,NATD,OR}ListenAddress were deprecated in 0.2.9.2-alpha and now have been removed. Use the ORPort option (and others) to configure listen-only and advertise-only addresses.
Removed features (tools):
We've removed the tor-checkkey tool from src/tools. Long ago, we used it to help people detect RSA keys that were generated by versions of Debian affected by CVE-2008-0166. But those keys have been out of circulation for ages, and this tool is no longer required. Closes ticket 21842.

New in Tor 0.3.1.6 RC (Sep 6, 2017)

Tor 0.3.1.6-rc fixes a few small bugs and annoyances in the 0.3.1 release series, including a bug that produced weird behavior on Windows directory caches.
This is the first release candidate in the Tor 0.3.1 series. If we find no new bugs or regressions here, the first stable 0.3.1 release will be nearly identical to it.
Major bug fixes (windows, directory cache):
On Windows, do not try to delete cached consensus documents and diffs before they are unmapped from memory--Windows won't allow that. Instead, allow the consensus cache directory to grow larger, to hold files that might need to stay around longer. Fixes bug 22752; bugfix on 0.3.1.1-alpha.
Minor features (directory authority):
Improve the message that authorities report to relays that present RSA/Ed25519 keypairs that conflict with previously pinned keys. Closes ticket 22348.
Minor features (geoip):
Update geoip and geoip6 to the August 3 2017 Maxmind GeoLite2 Country database.
Minor features (testing):
Add more tests for compression backend initialization. Closes ticket 22286.
Minor bug fixes (directory cache):
Fix a memory leak when recovering space in the consensus cache. Fixes bug 23139; bugfix on 0.3.1.1-alpha.
Minor bug fixes (hidden service):
Increase the number of circuits that a service is allowed to open over a specific period of time. The value was lower than it should be (8 vs 12) in the normal case of 3 introduction points. Fixes bug 22159; bugfix on 0.3.0.5-rc.
Fix a BUG warning during HSv3 descriptor decoding that could be cause by a specially crafted descriptor. Fixes bug 23233; bugfix on 0.3.0.1-alpha. Bug found by "haxxpop".
Rate-limit the log messages if we exceed the maximum number of allowed intro circuits. Fixes bug 22159; bugfix on 0.3.1.1-alpha.
Minor bug fixes (logging, relay):
Remove a forgotten debugging message when an introduction point successfully establishes a hidden service prop224 circuit with a client.
Change three other log_warn() for an introduction point to protocol warnings, because they can be failure from the network and are not relevant to the operator. Fixes bug 23078; bugfix on 0.3.0.1-alpha and 0.3.0.2-alpha.
Minor bug fixes (relay):
When a relay is not running as a directory cache, it will no longer generate compressed consensuses and consensus diff information. Previously, this was a waste of disk and CPU. Fixes bug 23275; bugfix on 0.3.1.1-alpha.
Minor bug fixes (robustness, error handling):
Improve our handling of the cases where OpenSSL encounters a memory error while encoding keys and certificates. We haven't observed these errors in the wild, but if they do happen, we now detect and respond better. Fixes bug 19418; bugfix on all versions of Tor. Reported by Guido Vranken.
Minor bug fixes (stability):
Avoid crashing on a double-free when unable to load or process an included file. Fixes bug 23155; bugfix on 0.3.1.1-alpha. Found with the clang static analyzer.
Minor bug fixes (testing):
Fix an undersized buffer in test-memwipe.c. Fixes bug 23291; bugfix on 0.2.7.2-alpha. Found and patched by Ties Stuij.
Port the hs_ntor handshake test to work correctly with recent versions of the pysha3 module. Fixes bug 23071; bugfix on 0.3.1.1-alpha.
Minor bug fixes (Windows service):
When running as a Windows service, set the ID of the main thread correctly. Failure to do so made us fail to send log messages to the controller in 0.2.1.16-rc, slowed down controller event delivery in 0.2.7.3-rc and later, and crash with an assertion failure in 0.3.1.1-alpha. Fixes bug 23081; bugfix on 0.2.1.6-alpha. Patch and diagnosis from "Vort".

New in Tor 0.3.0.10 (Aug 3, 2017)

Tor 0.3.0.10 backports a collection of small-to-medium bug fixes from the current Tor alpha series. OpenBSD users and TPROXY users should upgrade; others are probably okay sticking with 0.3.0.9.
Major features (build system, continuous integration, backport from 0.3.1.5-alpha):
Tor's repository now includes a Travis Continuous Integration (CI) configuration file (.travis.yml). This is meant to help new developers and contributors who fork Tor to a Github repository be better able to test their changes, and understand what we expect to pass. To use this new build feature, you must fork Tor to your Github account, then go into the "Integrations" menu in the repository settings for your fork and enable Travis, then push your changes. Closes ticket 22636.
Major bug fixes (linux TPROXY support, backport from 0.3.1.1-alpha):
Fix a typo that had prevented TPROXY-based transparent proxying from working under Linux. Fixes bug 18100; bugfix on 0.2.6.3-alpha. Patch from "d4fq0fQAgoJ".
Major bug fixes (openbsd, denial-of-service, backport from 0.3.1.5-alpha):
Avoid an assertion failure bug affecting our implementation of inet_pton(AF_INET6) on certain OpenBSD systems whose strtol() handling of "0xfoo" differs from what we had expected. Fixes bug 22789; bugfix on 0.2.3.8-alpha. Also tracked as TROVE-2017-007.
Minor features (backport from 0.3.1.5-alpha):
Update geoip and geoip6 to the July 4 2017 Maxmind GeoLite2 Country database.
Minor bug fixes (bandwidth accounting, backport from 0.3.1.2-alpha):
Roll over monthly accounting at the configured hour and minute, rather than always at 00:00. Fixes bug 22245; bugfix on 0.0.9rc1. Found by Andrey Karpov with PVS-Studio.
Minor bug fixes (compilation warnings, backport from 0.3.1.5-alpha):
Suppress -Wdouble-promotion warnings with clang 4.0. Fixes bug 22915; bugfix on 0.2.8.1-alpha.
Fix warnings when building with libscrypt and openssl scrypt support on Clang. Fixes bug 22916; bugfix on 0.2.7.2-alpha.
When building with certain versions of the mingw C header files, avoid float-conversion warnings when calling the C functions isfinite(), isnan(), and signbit(). Fixes bug 22801; bugfix on 0.2.8.1-alpha.
Minor bug fixes (compilation, mingw, backport from 0.3.1.1-alpha):
Backport a fix for an "unused variable" warning that appeared in some versions of mingw. Fixes bug 22838; bugfix on 0.2.8.1-alpha.
Minor bug fixes (coverity build support, backport from 0.3.1.5-alpha):
Avoid Coverity build warnings related to our BUG() macro. By default, Coverity treats BUG() as the Linux kernel does: an instant abort(). We need to override that so our BUG() macro doesn't prevent Coverity from analyzing functions that use it. Fixes bug 23030; bugfix on 0.2.9.1-alpha.
Minor bug fixes (directory authority, backport from 0.3.1.1-alpha):
When rejecting a router descriptor for running an obsolete version of Tor without ntor support, warn about the obsolete tor version, not the missing ntor key. Fixes bug 20270; bugfix on 0.2.9.3-alpha.
Minor bug fixes (linux seccomp2 sandbox, backport from 0.3.1.5-alpha):
Avoid a sandbox failure when trying to re-bind to a socket and mark it as IPv6-only. Fixes bug 20247; bugfix on 0.2.5.1-alpha.
Minor bug fixes (unit tests, backport from 0.3.1.5-alpha)
Fix a memory leak in the link-handshake/certs_ok_ed25519 test. Fixes bug 22803; bugfix on 0.3.0.1-alpha.

New in Tor 0.3.1.5 Alpha (Aug 2, 2017)

Tor 0.3.1.5-alpha improves the performance of consensus diff calculation, fixes a crash bug on older versions of OpenBSD, and fixes several other bugs. If no serious bugs are found in this version, the next version will be a release candidate.
This release also marks the end of support for the Tor 0.2.4.x, 0.2.6.x, and 0.2.7.x release series. Those releases will receive no further bug or security fixes. Anyone still running or distributing one of those versions should upgrade.
Major features (build system, continuous integration):
Tor's repository now includes a Travis Continuous Integration (CI) configuration file (.travis.yml). This is meant to help new developers and contributors who fork Tor to a Github repository be better able to test their changes, and understand what we expect to pass. To use this new build feature, you must fork Tor to your Github account, then go into the "Integrations" menu in the repository settings for your fork and enable Travis, then push your changes. Closes ticket 22636.
Major bug fixes (openbsd, denial-of-service):
Avoid an assertion failure bug affecting our implementation of inet_pton(AF_INET6) on certain OpenBSD systems whose strtol() handling of "0xfoo" differs from what we had expected. Fixes bug 22789; bugfix on 0.2.3.8-alpha. Also tracked as TROVE-2017-007.
Major bug fixes (relay, performance):
Perform circuit handshake operations at a higher priority than we use for consensus diff creation and compression. This should prevent circuits from starving when a relay or bridge receives a new consensus, especially on lower-powered machines. Fixes bug 22883; bugfix on 0.3.1.1-alpha.
Minor features (bridge authority):
Add "fingerprint" lines to the networkstatus-bridges file produced by bridge authorities. Closes ticket 22207.
Minor features (directory cache, consensus diff):
Add a new MaxConsensusAgeForDiffs option to allow directory cache operators with low-resource environments to adjust the number of consensuses they'll store and generate diffs from. Most cache operators should leave it unchanged. Helps to work around bug 22883.
Minor features (geoip):
Update geoip and geoip6 to the July 4 2017 Maxmind GeoLite2 Country database.
Minor features (relay, performance):
Always start relays with at least two worker threads, to prevent priority inversion on slow tasks. Part of the fix for bug 22883.
Allow background work to be queued with different priorities, so that a big pile of slow low-priority jobs will not starve out higher priority jobs. This lays the groundwork for a fix for bug 22883.
Minor bug fixes (build system, rust):
Fix a problem where Rust toolchains were not being found when building without --enable-cargo-online-mode, due to setting the $HOME environment variable instead of $CARGO_HOME. Fixes bug 22830; bugfix on 0.3.1.1-alpha. Fix by Chelsea Komlo.
Minor bug fixes (compatibility, zstd):
Write zstd epilogues correctly when the epilogue requires reallocation of the output buffer, even with zstd 1.3.0. (Previously, we worked on 1.2.0 and failed with 1.3.0). Fixes bug 22927; bugfix on 0.3.1.1-alpha.
Minor bug fixes (compilation warnings):
Suppress -Wdouble-promotion warnings with clang 4.0. Fixes bug 22915; bugfix on 0.2.8.1-alpha.
Fix warnings when building with libscrypt and openssl scrypt support on Clang. Fixes bug 22916; bugfix on 0.2.7.2-alpha.
Compile correctly when both openssl 1.1.0 and libscrypt are detected. Previously this would cause an error. Fixes bug 22892; bugfix on 0.3.1.1-alpha.
When building with certain versions of the mingw C header files, avoid float-conversion warnings when calling the C functions isfinite(), isnan(), and signbit(). Fixes bug 22801; bugfix on 0.2.8.1-alpha.
Minor bug fixes (coverity build support):
Avoid Coverity build warnings related to our BUG() macro. By default, Coverity treats BUG() as the Linux kernel does: an instant abort(). We need to override that so our BUG() macro doesn't prevent Coverity from analyzing functions that use it. Fixes bug 23030; bugfix on 0.2.9.1-alpha.
Minor bug fixes (directory authority):
When a directory authority rejects a descriptor or extrainfo with a given digest, mark that digest as undownloadable, so that we do not attempt to download it again over and over. We previously tried to avoid downloading such descriptors by other means, but we didn't notice if we accidentally downloaded one anyway. This behavior became problematic in 0.2.7.2-alpha, when authorities began pinning Ed25519 keys. Fixes bug 22349; bugfix on 0.2.1.19-alpha.
Minor bug fixes (error reporting, windows):
When formatting Windows error messages, use the English format to avoid codepage issues. Fixes bug 22520; bugfix on 0.1.2.8-alpha. Patch from "Vort".
Minor bug fixes (file limits, osx):
When setting the maximum number of connections allowed by the OS, always allow some extra file descriptors for other files. Fixes bug 22797; bugfix on 0.2.0.10-alpha.
Minor bug fixes (linux seccomp2 sandbox):
Avoid a sandbox failure when trying to re-bind to a socket and mark it as IPv6-only. Fixes bug 20247; bugfix on 0.2.5.1-alpha.
Minor bug fixes (memory leaks):
Fix a small memory leak when validating a configuration that uses two or more AF_UNIX sockets for the same port type. Fixes bug 23053; bugfix on 0.2.6.3-alpha. This is CID 1415725.
Minor bug fixes (unit tests):
test_consdiff_base64cmp would fail on OS X because while OS X follows the standard of (less than zero/zero/greater than zero), it doesn't follow the convention of (-1/0/+1). Make the test comply with the standard. Fixes bug 22870; bugfix on 0.3.1.1-alpha.
Fix a memory leak in the link-handshake/certs_ok_ed25519 test. Fixes bug 22803; bugfix on 0.3.0.1-alpha.

New in Tor 0.3.0.9 (Jun 30, 2017)

Tor 0.3.0.9 fixes a path selection bug that would allow a client to use a guard that was in the same network family as a chosen exit relay. This is a security regression; all clients running earlier versions of 0.3.0.x or 0.3.1.x should upgrade to 0.3.0.9 or 0.3.1.4-alpha.
This release also backports several other bug fixes from the 0.3.1.x series.
Major bug fixes (path selection, security, backport from 0.3.1.4-alpha):
When choosing which guard to use for a circuit, avoid the exit's family along with the exit itself. Previously, the new guard selection logic avoided the exit, but did not consider its family. Fixes bug 22753; bugfix on 0.3.0.1-alpha. Tracked as TROVE-2016- 006 and CVE-2017-0377.
Major bug fixes (entry guards, backport from 0.3.1.1-alpha):
Don't block bootstrapping when a primary bridge is offline and we can't get its descriptor. Fixes bug 22325; fixes one case of bug 21969; bugfix on 0.3.0.3-alpha.
Major bug fixes (entry guards, backport from 0.3.1.4-alpha):
When starting with an old consensus, do not add new entry guards unless the consensus is "reasonably live" (under 1 day old). Fixes one root cause of bug 22400; bugfix on 0.3.0.1-alpha.
Minor features (geoip):
Update geoip and geoip6 to the June 8 2017 Maxmind GeoLite2 Country database.
Minor bug fixes (voting consistency, backport from 0.3.1.1-alpha):
Reject version numbers with non-numeric prefixes (such as +, -, or whitespace). Disallowing whitespace prevents differential version parsing between POSIX-based and Windows platforms. Fixes bug 21507 and part of 21508; bugfix on 0.0.8pre1.
Minor bug fixes (linux seccomp2 sandbox, backport from 0.3.1.4-alpha):
Permit the fchmod system call, to avoid crashing on startup when starting with the seccomp2 sandbox and an unexpected set of permissions on the data directory or its contents. Fixes bug 22516; bugfix on 0.2.5.4-alpha.
Minor bug fixes (defensive programming, backport from 0.3.1.4-alpha):
Fix a memset() off the end of an array when packing cells. This bug should be harmless in practice, since the corrupted bytes are still in the same structure, and are always padding bytes, ignored, or immediately overwritten, depending on compiler behavior. Nevertheless, because the memset()'s purpose is to make sure that any other cell-handling bugs can't expose bytes to the network, we need to fix it. Fixes bug 22737; bugfix on 0.2.4.11-alpha. Fixes CID 1401591.

New in Tor 0.3.0.8 (Jun 9, 2017)

Tor 0.3.0.8 fixes a pair of bugs that would allow an attacker to remotely crash a hidden service with an assertion failure. Anyone running a hidden service should upgrade to this version, or to some other version with fixes for TROVE-2017-004 and TROVE-2017-005.
Tor 0.3.0.8 also includes fixes for several key management bugs that sometimes made relays unreliable, as well as several other bug fixes described below.
Major bug fixes (hidden service, relay, security, backport from 0.3.1.3-alpha):
Fix a remotely triggerable assertion failure when a hidden service handles a malformed BEGIN cell. Fixes bug 22493, tracked as TROVE-2017-004 and as CVE-2017-0375; bugfix on 0.3.0.1-alpha.
Fix a remotely triggerable assertion failure caused by receiving a BEGIN_DIR cell on a hidden service rendezvous circuit. Fixes bug 22494, tracked as TROVE-2017-005 and CVE-2017-0376; bugfix on 0.2.2.1-alpha.
Major bug fixes (relay, link handshake, backport from 0.3.1.3-alpha):
When performing the v3 link handshake on a TLS connection, report that we have the x509 certificate that we actually used on that connection, even if we have changed certificates since that connection was first opened. Previously, we would claim to have used our most recent x509 link certificate, which would sometimes make the link handshake fail. Fixes one case of bug 22460; bugfix on 0.2.3.6-alpha.
Major bug fixes (relays, key management, backport from 0.3.1.3-alpha):
Regenerate link and authentication certificates whenever the key that signs them changes; also, regenerate link certificates whenever the signed key changes. Previously, these processes were only weakly coupled, and we relays could (for minutes to hours) wind up with an inconsistent set of keys and certificates, which other relays would not accept. Fixes two cases of bug 22460; bugfix on 0.3.0.1-alpha.
When sending an Ed25519 signing->link certificate in a CERTS cell, send the certificate that matches the x509 certificate that we used on the TLS connection. Previously, there was a race condition if the TLS context rotated after we began the TLS handshake but before we sent the CERTS cell. Fixes a case of bug 22460; bugfix on 0.3.0.1-alpha.
Major bug fixes (hidden service v3, backport from 0.3.1.1-alpha):
Stop rejecting v3 hidden service descriptors because their size did not match an old padding rule. Fixes bug 22447; bugfix on tor-0.3.0.1-alpha.
Minor features (fallback directory list, backport from 0.3.1.3-alpha):
Replace the 177 fallbacks originally introduced in Tor 0.2.9.8 in December 2016 (of which ~126 were still functional) with a list of 151 fallbacks (32 new, 119 unchanged, 58 removed) generated in May 2017. Resolves ticket 21564.
Minor bug fixes (configuration, backport from 0.3.1.1-alpha):
Do not crash when starting with LearnCircuitBuildTimeout 0. Fixes bug 22252; bugfix on 0.2.9.3-alpha.
Minor bug fixes (correctness, backport from 0.3.1.3-alpha):
Avoid undefined behavior when parsing IPv6 entries from the geoip6 file. Fixes bug 22490; bugfix on 0.2.4.6-alpha.
Minor bug fixes (link handshake, backport from 0.3.1.3-alpha):
Lower the lifetime of the RSA->Ed25519 cross-certificate to six months, and regenerate it when it is within one month of expiring. Previously, we had generated this certificate at startup with a ten-year lifetime, but that could lead to weird behavior when Tor was started with a grossly inaccurate clock. Mitigates bug 22466; mitigation on 0.3.0.1-alpha.
Minor bug fixes (memory leak, directory authority, backport from 0.3.1.2-alpha):
When directory authorities reject a router descriptor due to keypinning, free the router descriptor rather than leaking the memory. Fixes bug 22370; bugfix on 0.2.7.2-alpha.

New in Tor 0.3.1.2 Alpha (May 27, 2017)

New in Tor 0.3.0.7 (May 16, 2017)

New in Tor 0.3.0.6 (Apr 27, 2017)

New in Tor 0.3.0.5 RC (Apr 5, 2017)

Tor 0.3.0.5-rc fixes a few remaining bugs, large and small, in the 0.3.0 release series.
This is the second release candidate in the Tor 0.3.0 series, and has much fewer changes than the first. If we find no new bugs or regressions here, the first stable 0.3.0 release will be nearly identical to it.
Major bug fixes (crash, directory connections):
Fix a rare crash when sending a begin cell on a circuit whose linked directory connection had already been closed. Fixes bug 21576; bugfix on 0.2.9.3-alpha. Reported by Alec Muffett.
Major bug fixes (guard selection):
Fix a guard selection bug where Tor would refuse to bootstrap in some cases if the user swapped a bridge for another bridge in their configuration file. Fixes bug 21771; bugfix on 0.3.0.1-alpha. Reported by "torvlnt33r".
Minor features (geoip):
Update geoip and geoip6 to the March 7 2017 Maxmind GeoLite2 Country database.
Minor bugfix (compilation):
Fix a warning when compiling hs_service.c. Previously, it had no exported symbols when compiled for libor.a, resulting in a compilation warning from clang. Fixes bug 21825; bugfix on 0.3.0.1-alpha.
Minor bug fixes (hidden services):
Make hidden services check for failed intro point connections, even when they have exceeded their intro point creation limit. Fixes bug 21596; bugfix on 0.2.7.2-alpha. Reported by Alec Muffett.
Make hidden services with 8 to 10 introduction points check for failed circuits immediately after startup. Previously, they would wait for 5 minutes before performing their first checks. Fixes bug 21594; bugfix on 0.2.3.9-alpha. Reported by Alec Muffett.
Minor bug fixes (memory leaks):
Fix a memory leak when using GETCONF on a port option. Fixes bug 21682; bugfix on 0.3.0.3-alpha.
Minor bug fixes (relay):
Avoid a double-marked-circuit warning that could happen when we receive DESTROY cells under heavy load. Fixes bug 20059; bugfix on 0.1.0.1-rc.
Minor bug fixes (tests):
Run the entry_guard_parse_from_state_full() test with the time set to a specific date. (The guard state that this test was parsing contained guards that had expired since the test was first written.) Fixes bug 21799; bugfix on 0.3.0.1-alpha.
Documentation:
Update the description of the directory server options in the manual page, to clarify that a relay no longer needs to set DirPort in order to be a directory cache. Closes ticket 21720.

New in Tor 0.3.0.4 RC (Mar 1, 2017)

Tor 0.3.0.4-rc fixes some remaining bugs, large and small, in the 0.3.0 release series, and introduces a few reliability features to keep them from coming back.
This is the first release candidate in the Tor 0.3.0 series. If we find no new bugs or regressions here, the first stable 0.3.0 release will be nearly identical to it.
Major bug fixes (bridges):
When the same bridge is configured multiple times with the same identity, but at different address:port combinations, treat those bridge instances as separate guards. This fix restores the ability of clients to configure the same bridge with multiple pluggable transports. Fixes bug 21027; bug fix on 0.3.0.1-alpha.
Major bug fixes (hidden service directory v3):
Stop crashing on a failed v3 hidden service descriptor lookup failure. Fixes bug 21471; bug fixes on tor-0.3.0.1-alpha.
Major bug fixes (parsing):
When parsing a malformed content-length field from an HTTP message, do not read off the end of the buffer. This bug was a potential remote denial-of-service attack against Tor clients and relays. A workaround was released in October 2016, to prevent this bug from crashing Tor. This is a fix for the underlying issue, which should no longer matter (if you applied the earlier patch). Fixes bug 20894; bug fix on 0.2.0.16-alpha. Bug found by fuzzing using AFL (http://lcamtuf.coredump.cx/afl/).
Fix an integer underflow bug when comparing malformed Tor versions. This bug could crash Tor when built with --enable-expensive-hardening, or on Tor 0.2.9.1-alpha through Tor 0.2.9.8, which were built with -ftrapv by default. In other cases it was harmless. Part of TROVE-2017-001. Fixes bug 21278; bug fix on 0.0.8pre1. Found by OSS-Fuzz.
Minor feature (protocol versioning):
Add new protocol version for proposal 224. HSIntro now advertises version "3-4" and HSDir version "1-2". Fixes ticket 20656.
Minor features (directory authorities):
Directory authorities now reject descriptors that claim to be malformed versions of Tor. Helps prevent exploitation of bug 21278.
Reject version numbers with components that exceed INT32_MAX. Otherwise 32-bit and 64-bit platforms would behave inconsistently. Fixes bug 21450; bug fix on 0.0.8pre1.
Minor features (geoip):
Update geoip and geoip6 to the February 8 2017 Maxmind GeoLite2 Country database.
Minor features (reliability, crash):
Try better to detect problems in buffers where they might grow (or think they have grown) over 2 GB in size. Diagnostic for bug 21369.
Minor features (testing):
During 'make test-network-all', if tor logs any warnings, ask chutney to output them. Requires a recent version of chutney with the 21572 patch. Implements 21570.
Minor bug fixes (certificate expiration time):
Avoid using link certificates that don't become valid till some time in the future. Fixes bug 21420; bug fix on 0.2.4.11-alpha
Minor bug fixes (code correctness):
Repair a couple of (unreachable or harmless) cases of the risky comparison-by-subtraction pattern that caused bug 21278.
Remove a redundant check for the UseEntryGuards option from the options_transition_affects_guards() function. Fixes bug 21492; bug fix on 0.3.0.1-alpha.
Minor bug fixes (directory mirrors):
Allow relays to use directory mirrors without a DirPort: these relays need to be contacted over their ORPorts using a begindir connection. Fixes one case of bug 20711; bug fix on 0.2.8.2-alpha.
Clarify the message logged when a remote relay is unexpectedly missing an ORPort or DirPort: users were confusing this with a local port. Fixes another case of bug 20711; bug fix on 0.2.8.2-alpha.
Minor bug fixes (guards):
Don't warn about a missing guard state on timeout-measurement circuits: they aren't supposed to be using guards. Fixes an instance of bug 21007; bug fix on 0.3.0.1-alpha.
Silence a BUG() warning when attempting to use a guard whose descriptor we don't know, and make this scenario less likely to happen. Fixes bug 21415; bug fix on 0.3.0.1-alpha.
Minor bug fixes (hidden service):
Pass correct buffer length when encoding legacy ESTABLISH_INTRO cells. Previously, we were using sizeof() on a pointer, instead of the real destination buffer. Fortunately, that value was only used to double-check that there was enough room--which was already enforced elsewhere. Fixes bug 21553; bug fix on 0.3.0.1-alpha.
Minor bug fixes (testing):
Fix Raspbian build issues related to missing socket errno in test_util.c. Fixes bug 21116; bug fix on tor-0.2.8.2. Patch by "hein".
Rename "make fuzz" to "make test-fuzz-corpora", since it doesn't actually fuzz anything. Fixes bug 21447; bug fix on 0.3.0.3-alpha.
Use bash in src/test/test-network.sh. This ensures we reliably call chutney's newer tools/test-network.sh when available. Fixes bug 21562; bug fix on 0.2.9.1-alpha.
Documentation:
Small fixes to the fuzzing documentation. Closes ticket 21472.

New in Tor 0.2.9.10 (Mar 1, 2017)

Tor 0.2.9.10 backports a security fix from later Tor release. It also includes fixes for some major issues affecting directory authorities, LibreSSL compatibility, and IPv6 correctness.
The Tor 0.2.9.x release series is now marked as a long-term-support series. We intend to backport security fixes to 0.2.9.x until at least January of 2020.
Major bug fixes (directory authority, 0.3.0.3-alpha):
During voting, when marking a relay as a probable sybil, do not clear its BadExit flag: sybils can still be bad in other ways too. (We still clear the other flags.) Fixes bug 21108; bug fix on 0.2.0.13-alpha.
Major bug fixes (IPv6 Exits, backport from 0.3.0.3-alpha):
Stop rejecting all IPv6 traffic on Exits whose exit policy rejects any IPv6 addresses. Instead, only reject a port over IPv6 if the exit policy rejects that port on more than an IPv6 /16 of addresses. This bug was made worse by 17027 in 0.2.8.1-alpha, which rejected a relay's own IPv6 address by default. Fixes bug 21357; bug fix on commit 004f3f4e53 in 0.2.4.7-alpha.
Major bug fixes (parsing, also in 0.3.0.4-rc):
Fix an integer underflow bug when comparing malformed Tor versions. This bug could crash Tor when built with --enable-expensive-hardening, or on Tor 0.2.9.1-alpha through Tor 0.2.9.8, which were built with -ftrapv by default. In other cases it was harmless. Part of TROVE-2017-001. Fixes bug 21278; bug fix on 0.0.8pre1. Found by OSS-Fuzz.
Minor features (directory authorities, also in 0.3.0.4-rc):
Directory authorities now reject descriptors that claim to be malformed versions of Tor. Helps prevent exploitation of bug 21278.
Reject version numbers with components that exceed INT32_MAX. Otherwise 32-bit and 64-bit platforms would behave inconsistently. Fixes bug 21450; bug fix on 0.0.8pre1.
Minor features (geoip):
Update geoip and geoip6 to the February 8 2017 Maxmind GeoLite2 Country database.
Minor features (portability, compilation, backport from 0.3.0.3-alpha):
Autoconf now checks to determine if OpenSSL structures are opaque, instead of explicitly checking for OpenSSL version numbers. Part of ticket 21359.
Support building with recent LibreSSL code that uses opaque structures. Closes ticket 21359.
Minor bug fixes (code correctness, also in 0.3.0.4-rc):
Repair a couple of (unreachable or harmless) cases of the risky comparison-by-subtraction pattern that caused bug 21278.
Minor bug fixes (tor-resolve, backport from 0.3.0.3-alpha):
The tor-resolve command line tool now rejects hostnames over 255 characters in length. Previously, it would silently truncate them, which could lead to bugs. Fixes bug 21280; bug fix on 0.0.9pre5. Patch by "junglefowl".

New in Tor 0.3.0.3 Alpha (Feb 3, 2017)

Tor 0.3.0.3-alpha fixes a few significant bugs introduced over the 0.3.0.x development series, including some that could cause authorities to behave badly. There is also a fix for a longstanding bug that could prevent IPv6 exits from working. Tor 0.3.0.3-alpha also includes some smaller features and bug fixes.
The Tor 0.3.0.x release series is now in patch-freeze: no additional features will be considered for inclusion in 0.3.0.x. We suspect that some bugs will probably remain, however, and we encourage people to test this release.
Major bug fixes (directory authority):
During voting, when marking a relay as a probable sybil, do not clear its BadExit flag: sybils can still be bad in other ways too. (We still clear the other flags.) Fixes bug 21108; bugfix on 0.2.0.13-alpha.
When deciding whether we have just found a router to be reachable, do not penalize it for not having performed an Ed25519 link handshake if it does not claim to support an Ed25519 handshake. Previously, we would treat such relays as non-running. Fixes bug 21107; bugfix on 0.3.0.1-alpha.
Major bug fixes (entry guards):
Stop trying to build circuits through entry guards for which we have no descriptor. Also, stop crashing in the case that we *do* accidentally try to build a circuit in such a state. Fixes bug 21242; bugfix on 0.3.0.1-alpha.
Major bug fixes (IPv6 Exits):
Stop rejecting all IPv6 traffic on Exits whose exit policy rejects any IPv6 addresses. Instead, only reject a port over IPv6 if the exit policy rejects that port on more than an IPv6 /16 of addresses. This bug was made worse by 17027 in 0.2.8.1-alpha, which rejected a relay's own IPv6 address by default. Fixes bug 21357; bugfix on commit 004f3f4e53 in 0.2.4.7-alpha.
Minor feature (client):
Enable IPv6 traffic on the SocksPort by default. To disable this, a user will have to specify "NoIPv6Traffic". Closes ticket 21269.
Minor feature (fallback scripts):
Add a check_existing mode to updateFallbackDirs.py, which checks if fallbacks in the hard-coded list are working. Closes ticket 20174. Patch by haxxpop.
Minor features (ciphersuite selection):
Clients now advertise a list of ciphersuites closer to the ones preferred by Firefox. Closes part of ticket 15426.
Allow relays to accept a wider range of ciphersuites, including chacha20-poly1305 and AES-CCM. Closes the other part of 15426.
Minor features (controller, configuration):
Each of the *Port options, such as SocksPort, ORPort, ControlPort, and so on, now comes with a __*Port variant that will not be saved to the torrc file by the controller's SAVECONF command. This change allows TorBrowser to set up a single-use domain socket for each time it launches Tor. Closes ticket 20956.
The GETCONF command can now query options that may only be meaningful in context-sensitive lists. This allows the controller to query the mixed SocksPort/__SocksPort style options introduced in feature 20956. Implements ticket 21300.
Minor features (portability, compilation):
Autoconf now checks to determine if OpenSSL structures are opaque, instead of explicitly checking for OpenSSL version numbers. Part of ticket 21359.
Support building with recent LibreSSL code that uses opaque structures. Closes ticket 21359.
Minor features (relay):
We now allow separation of exit and relay traffic to different source IP addresses, using the OutboundBindAddressExit and OutboundBindAddressOR options respectively. Closes ticket 17975. Written by Michael Sonntag.
Minor bugfix (logging):
Don't recommend the use of Tor2web in non-anonymous mode. Recommending Tor2web is a bad idea because the client loses all anonymity. Tor2web should only be used in specific cases by users who *know* and understand the issues. Fixes bug 21294; bugfix on 0.2.9.3-alpha.
Minor bug fixes (client):
Always recover from failures in extend_info_from_node(), in an attempt to prevent any recurrence of bug 21242. Fixes bug 21372; bugfix on 0.2.3.1-alpha.
Minor bug fixes (client, entry guards):
Fix a bug warning (with backtrace) when we fail a channel that circuits to fallback directories on it. Fixes bug 21128; bugfix on 0.3.0.1-alpha.
Fix a spurious bug warning (with backtrace) when removing an expired entry guard. Fixes bug 21129; bugfix on 0.3.0.1-alpha.
Fix a bug of the new guard algorithm where tor could stall for up to 10 minutes before retrying a guard after a long period of no network. Fixes bug 21052; bugfix on 0.3.0.1-alpha.
Do not try to build circuits until we have descriptors for our primary entry guards. Related to fix for bug 21242.
Minor bug fixes (configure, autoconf):
Rename the configure option --enable-expensive-hardening to --enable-fragile-hardening. Expensive hardening makes the tor daemon abort when some kinds of issues are detected. Thus, it makes tor more at risk of remote crashes but safer against RCE or heartbleed bug category. We now try to explain this issue in a message from the configure script. Fixes bug 21290; bugfix on 0.2.5.4-alpha.
Minor bug fixes (controller):
Restore the (deprecated) DROPGUARDS controller command. Fixes bug 20824; bugfix on 0.3.0.1-alpha.
Minor bug fixes (hidden service):
Clean up the code for expiring intro points with no associated circuits. It was causing, rarely, a service with some expiring introduction points to not open enough additional introduction points. Fixes part of bug 21302; bugfix on 0.2.7.2-alpha.
Stop setting the torrc option HiddenServiceStatistics to "0" just because we're not a bridge or relay. Instead, we preserve whatever value the user set (or didn't set). Fixes bug 21150; bugfix on 0.2.6.2-alpha.
Resolve two possible underflows which could lead to creating and closing a lot of introduction point circuits in a non-stop loop. Fixes bug 21302; bugfix on 0.2.7.2-alpha.
Minor bug fixes (portability):
Use "OpenBSD" compiler macro instead of "OPENBSD" or "__OpenBSD__". It is supported by OpenBSD itself, and also by most OpenBSD variants (such as Bitrig). Fixes bug 20980; bugfix on 0.1.2.1-alpha.
When mapping a file of length greater than SIZE_MAX, do not silently truncate its contents. This issue could occur on 32 bit systems with large file support and files which are larger than 4 GB. Fixes bug 21134; bugfix on 0.3.0.1-alpha.
Minor bug fixes (tor-resolve):
The tor-resolve command line tool now rejects hostnames over 255 characters in length. Previously, it would silently truncate them, which could lead to bugs. Fixes bug 21280; bugfix on 0.0.9pre5. Patch by "junglefowl".
Minor bug fixes (Windows services):
Be sure to initialize the monotonic time subsystem before using it, even when running as an NT service. Fixes bug 21356; bugfix on 0.2.9.1-alpha.

New in Tor 0.2.9.9 (Jan 24, 2017)

New in Tor 0.3.0.2 Alpha (Jan 24, 2017)

New in Tor 0.3.0.1 Alpha (Dec 20, 2016)

Tor 0.3.0.1-alpha is the first alpha release in the 0.3.0 development series. It strengthens Tor's link and circuit handshakes by identifying relays by their Ed25519 keys, improves the algorithm that clients use to choose and maintain their list of guards, and includes additional backend support for the next-generation hidden service design. It also contains numerous other small features and improvements to security, correctness, and performance.
Major features (guard selection algorithm):
Tor's guard selection algorithm has been redesigned from the ground up, to better support unreliable networks and restrictive sets of entry nodes, and to better resist guard-capture attacks by hostile local networks. Implements proposal 271; closes ticket 19877.
Major features (next-generation hidden services):
Relays can now handle v3 ESTABLISH_INTRO cells as specified by prop224 aka "Next Generation Hidden Services". Service and clients don't use this functionality yet. Closes ticket 19043. Based on initial code by Alec Heifetz.
Relays now support the HSDir version 3 protocol, so that they can can store and serve v3 descriptors. This is part of the next- generation onion service work detailled in proposal 224. Closes ticket 17238.
Major features (protocol, ed25519 identity keys):
Relays now use Ed25519 to prove their Ed25519 identities and to one another, and to clients. This algorithm is faster and more secure than the RSA-based handshake we've been doing until now. Implements the second big part of proposal 220; Closes ticket 15055.
Clients now support including Ed25519 identity keys in the EXTEND2 cells they generate. By default, this is controlled by a consensus parameter, currently disabled. You can turn this feature on for testing by setting ExtendByEd25519ID in your configuration. This might make your traffic appear different than the traffic generated by other users, however. Implements part of ticket 15056; part of proposal 220.
Relays now understand requests to extend to other relays by their Ed25519 identity keys. When an Ed25519 identity key is included in an EXTEND2 cell, the relay will only extend the circuit if the other relay can prove ownership of that identity. Implements part of ticket 15056; part of proposal 220.
Major bug fixes (scheduler):
Actually compare circuit policies in ewma_cmp_cmux(). This bug caused the channel scheduler to behave more or less randomly, rather than preferring channels with higher-priority circuits. Fixes bug 20459; bugfix on 0.2.6.2-alpha.
Minor features (controller):
When HSFETCH arguments cannot be parsed, say "Invalid argument" rather than "unrecognized." Closes ticket 20389; patch from Ivan Markin.
Minor features (diagnostic, directory client):
Warn when we find an unexpected inconsistency in directory download status objects. Prevents some negative consequences of bug 20593.
Minor features (directory authority):
Add a new authority-only AuthDirTestEd25519LinkKeys option (on by default) to control whether authorities should try to probe relays by their Ed25519 link keys. This option will go away in a few releases--unless we encounter major trouble in our ed25519 link protocol rollout, in which case it will serve as a safety option.
Minor features (directory cache):
Relays and bridges will now refuse to serve the consensus they have if they know it is too old for a client to use. Closes ticket 20511.
Minor features (ed25519 link handshake):
Advertise support for the ed25519 link handshake using the subprotocol-versions mechanism, so that clients can tell which relays can identity themselves by Ed25519 ID. Closes ticket 20552.
Minor features (fingerprinting resistence, authentication):
Extend the length of RSA keys used for TLS link authentication to 2048 bits. (These weren't used for forward secrecy; for forward secrecy, we used P256.) Closes ticket 13752.
Minor features (infrastructure):
Implement smartlist_add_strdup() function. Replaces the use of smartlist_add(sl, tor_strdup(str)). Closes ticket 20048.
Minor bug fixes (client):
When clients that use bridges start up with a cached consensus on disk, they were ignoring it and downloading a new one. Now they use the cached one. Fixes bug 20269; bugfix on 0.2.3.12-alpha.
Minor bug fixes (configuration):
Accept non-space whitespace characters after the severity level in the `Log` option. Fixes bug 19965; bugfix on 0.2.1.1-alpha.
Support "TByte" and "TBytes" units in options given in bytes. "TB", "terabyte(s)", "TBit(s)" and "terabit(s)" were already supported. Fixes bug 20622; bugfix on 0.2.0.14-alpha.
Minor bug fixes (consensus weight):
Add new consensus method that initializes bw weights to 1 instead of 0. This prevents a zero weight from making it all the way to the end (happens in small testing networks) and causing an error. Fixes bug 14881; bugfix on 0.2.2.17-alpha.
Minor bug fixes (descriptors):
Correctly recognise downloaded full descriptors as valid, even when using microdescriptors as circuits. This affects clients with FetchUselessDescriptors set, and may affect directory authorities. Fixes bug 20839; bugfix on 0.2.3.2-alpha.
Minor bug fixes (directory system):
Download all consensus flavors, descriptors, and authority certificates when FetchUselessDescriptors is set, regardless of whether tor is a directory cache or not. Fixes bug 20667; bugfix on all recent tor versions.
Bridges and relays now use microdescriptors (like clients do) rather than old-style router descriptors. Now bridges will blend in with clients in terms of the circuits they build. Fixes bug 6769; bugfix on 0.2.3.2-alpha.
Minor bug fixes (ed25519 certificates):
Correctly interpret ed25519 certificates that would expire some time after 19 Jan 2038. Fixes bug 20027; bugfix on 0.2.7.2-alpha.
Minor bug fixes (hidden services):
Stop ignoring misconfigured hidden services. Instead, refuse to start tor until the misconfigurations have been corrected. Fixes bug 20559; bugfix on multiple commits in 0.2.7.1-alpha and earlier.
Minor bug fixes (memory leak at exit):
Fix a small harmless memory leak at exit of the previously unused RSA->Ed identity cross-certificate. Fixes bug 17779; bugfix on 0.2.7.2-alpha.
Minor bug fixes (util):
When finishing writing a file to disk, if we were about to replace the file with the temporary file created before and we fail to replace it, remove the temporary file so it doesn't stay on disk. Fixes bug 20646; bugfix on tor-0.2.0.7-alpha. Patch by fk.
Minor bug fixes (Windows):
Check for getpagesize before using it to mmap files. This fixes compilation in some MinGW environments. Fixes bug 20530; bugfix on 0.1.2.1-alpha. Reported by "ice".
Code simplification and refactoring:
Abolish all global guard context in entrynodes.c; replace with new guard_selection_t structure as preparation for proposal 271. Closes ticket 19858.
Introduce rend_service_is_ephemeral() that tells if given onion service is ephemeral. Replace unclear NULL-checkings for service directory with this function. Closes ticket 20526.
Extract magic numbers in circuituse.c into defined variables.
Refactor circuit_is_available_for_use to remove unnecessary check.
Refactor circuit_predict_and_launch_new for readability and testability. Closes ticket 18873.
Refactor large if statement in purpose_needs_anonymity to use switch statement instead. Closes part of ticket 20077.
Refactor the hashing API to return negative values for errors, as is done as throughout the codebase. Closes ticket 20717.
Remove data structures that were used to index or_connection objects by their RSA identity digests. These structures are fully redundant with the similar structures used in the channel abstraction.
Remove duplicate code in the channel_write_*cell() functions. Closes ticket 13827; patch from Pingl.
Remove redundant behavior of is_sensitive_dir_purpose, refactor to use only purpose_needs_anonymity. Closes part of ticket 20077.
The code to generate and parse EXTEND and EXTEND2 cells has been replaced with code automatically generated by the "trunnel" utility.
Documentation:
Include the "TBits" unit in Tor's man page. Fixes part of bug 20622; bugfix on tor-0.2.5.1-alpha.
Change '1' to 'weight_scale' in consensus bw weights calculation comments, as that is reality. Closes ticket 20273. Patch from pastly.
Correct the value for AuthDirGuardBWGuarantee in the manpage, from 250 KBytes to 2 MBytes. Fixes bug 20435; bugfix on tor-0.2.5.6-alpha.
Stop the man page from incorrectly stating that HiddenServiceDir must already exist. Fixes 20486.
Clarify that when ClientRejectInternalAddresses is enabled (which is the default), multicast DNS hostnames for machines on the local network (of the form *.local) are also rejected. Closes ticket 17070.
Removed features:
The AuthDirMaxServersPerAuthAddr option no longer exists: The same limit for relays running on a single IP applies to authority IP addresses as well as to non-authority IP addresses. Closes ticket 20960.
The UseDirectoryGuards torrc option no longer exists: all users that use entry guards will also use directory guards. Related to proposal 271; implements part of ticket 20831.
Testing:
New unit tests for tor_htonll(). Closes ticket 19563. Patch from "overcaffeinated".
Perform the coding style checks when running the tests and fail when coding style violations are found. Closes ticket 5500.
Add tests for networkstatus_compute_bw_weights_v10.
Add unit tests circuit_predict_and_launch_new.
Extract dummy_origin_circuit_new so it can be used by other test functions.

New in Tor 0.2.9.8 (Dec 19, 2016)

Tor 0.2.9.8 is the first stable release of the Tor 0.2.9 series.
The Tor 0.2.9 series makes mandatory a number of security features that were formerly optional. It includes support for a new shared-randomness protocol that will form the basis for next generation hidden services, includes a single-hop hidden service mode for optimizing .onion services that don't actually want to be hidden, tries harder not to overload the directory authorities with excessive downloads, and supports a better protocol versioning scheme for improved compatibility with other implementations of the Tor protocol.
And of course, there are numerous other bug fixes and improvements.
This release also includes a fix for a medium-severity issue (bug 21018 below) where Tor clients could crash when attempting to visit a hostile hidden service. Clients are recommended to upgrade as packages become available for their systems.
Below are listed the changes since Tor 0.2.8.11. For a list of changes since 0.2.9.7-rc, see the ChangeLog file.
New system requirements:
When building with OpenSSL, Tor now requires version 1.0.1 or later. OpenSSL 1.0.0 and earlier are no longer supported by the OpenSSL team, and should not be used. Closes ticket 20303.
Tor now requires Libevent version 2.0.10-stable or later. Older versions of Libevent have less efficient backends for several platforms, and lack the DNS code that we use for our server-side DNS support. This implements ticket 19554.
Tor now requires zlib version 1.2 or later, for security, efficiency, and (eventually) gzip support. (Back when we started, zlib 1.1 and zlib 1.0 were still found in the wild. 1.2 was released in 2003. We recommend the latest version.)
Deprecated features:
A number of DNS-cache-related sub-options for client ports are now deprecated for security reasons, and may be removed in a future version of Tor. (We believe that client-side DNS caching is a bad idea for anonymity, and you should not turn it on.) The options are: CacheDNS, CacheIPv4DNS, CacheIPv6DNS, UseDNSCache, UseIPv4Cache, and UseIPv6Cache.
A number of options are deprecated for security reasons, and may be removed in a future version of Tor. The options are: AllowDotExit, AllowInvalidNodes, AllowSingleHopCircuits, AllowSingleHopExits, ClientDNSRejectInternalAddresses, CloseHSClientCircuitsImmediatelyOnTimeout, CloseHSServiceRendCircuitsImmediatelyOnTimeout, ExcludeSingleHopRelays, FastFirstHopPK, TLSECGroup, UseNTorHandshake, and WarnUnsafeSocks.
The *ListenAddress options are now deprecated as unnecessary: the corresponding *Port options should be used instead. These options may someday be removed. The affected options are: ControlListenAddress, DNSListenAddress, DirListenAddress, NATDListenAddress, ORListenAddress, SocksListenAddress, and TransListenAddress.
Major bug fixes (parsing, security, new since 0.2.9.7-rc):
Fix a bug in parsing that could cause clients to read a single byte past the end of an allocated region. This bug could be used to cause hardened clients (built with --enable-expensive-hardening) to crash if they tried to visit a hostile hidden service. Non- hardened clients are only affected depending on the details of their platform's memory allocator. Fixes bug 21018; bug fix on 0.2.0.8-alpha. Found by using libFuzzer. Also tracked as TROVE- 2016-12-002 and as CVE-2016-1254.
Major features (build, hardening):
Tor now builds with -ftrapv by default on compilers that support it. This option detects signed integer overflow (which C forbids), and turns it into a hard-failure. We do not apply this option to code that needs to run in constant time to avoid side-channels; instead, we use -fwrapv in that code. Closes ticket 17983.
When --enable-expensive-hardening is selected, stop applying the clang/gcc sanitizers to code that needs to run in constant time. Although we are aware of no introduced side-channels, we are not able to prove that there are none. Related to ticket 17983.
Major features (circuit building, security):
Authorities, relays, and clients now require ntor keys in all descriptors, for all hops (except for rare hidden service protocol cases), for all circuits, and for all other roles. Part of ticket 19163.
Authorities, relays, and clients only use ntor, except for rare cases in the hidden service protocol. Part of ticket 19163.
Major features (compilation):
Our big list of extra GCC warnings is now enabled by default when building with GCC (or with anything like Clang that claims to be GCC-compatible). To make all warnings into fatal compilation errors, pass --enable-fatal-warnings to configure. Closes ticket 19044.
Use the Autoconf macro AC_USE_SYSTEM_EXTENSIONS to automatically turn on C and POSIX extensions. (Previously, we attempted to do this on an ad hoc basis.) Closes ticket 19139.
Major features (directory authorities, hidden services):
Directory authorities can now perform the shared randomness protocol specified by proposal 250. Using this protocol, directory authorities generate a global fresh random value every day. In the future, this value will be used by hidden services to select HSDirs. This release implements the directory authority feature; the hidden service side will be implemented in the future as part of proposal 224. Resolves ticket 16943; implements proposal 250.
Major features (downloading, random exponential backoff):
When we fail to download an object from a directory service, wait for an (exponentially increasing) randomized amount of time before retrying, rather than a fixed interval as we did before. This prevents a group of Tor instances from becoming too synchronized, or a single Tor instance from becoming too predictable, in its download schedule. Closes ticket 15942.
Major features (resource management):
Tor can now notice it is about to run out of sockets, and preemptively close connections of lower priority. (This feature is off by default for now, since the current prioritizing method is yet not mature enough. You can enable it by setting "DisableOOSCheck 0", but watch out: it might close some sockets you would rather have it keep.) Closes ticket 18640.
Major features (single-hop "hidden" services):
Add experimental HiddenServiceSingleHopMode and HiddenServiceNonAnonymousMode options. When both are set to 1, every hidden service on that Tor instance becomes a non-anonymous Single Onion Service. Single Onions make one-hop (direct) connections to their introduction and rendezvous points. One-hop circuits make Single Onion servers easily locatable, but clients remain location-anonymous. This is compatible with the existing hidden service implementation, and works on the current Tor network without any changes to older relays or clients. Implements proposal 260, completes ticket 17178. Patch by teor and asn.
Major features (subprotocol versions):
Tor directory authorities now vote on a set of recommended "subprotocol versions", and on a set of required subprotocol versions. Clients and relays that lack support for a _required_ subprotocol version will not start; those that lack support for a _recommended_ subprotocol version will warn the user to upgrade. This change allows compatible implementations of the Tor protocol(s) to exist without pretending to be 100% bug-compatible with particular releases of Tor itself. Closes ticket 19958; implements part of proposal 264.
Major bug fixes (circuit building):
Hidden service client-to-intro-point and service-to-rendezvous- point circuits use the TAP key supplied by the protocol, to avoid epistemic attacks. Fixes bug 19163; bug fix on 0.2.4.18-rc.
Major bug fixes (download scheduling):
Avoid resetting download status for consensuses hourly, since we already have another, smarter retry mechanism. Fixes bug 8625; bug fix on 0.2.0.9-alpha.
If a consensus expires while we are waiting for certificates to download, stop waiting for certificates.
If we stop waiting for certificates less than a minute after we started downloading them, do not consider the certificate download failure a separate failure. Fixes bug 20533; bug fix on 0.2.0.9-alpha.
When using exponential backoff in test networks, use a lower exponent, so the delays do not vary as much. This helps test networks bootstrap consistently. Fixes bug 20597; bug fix on 20499.
Major bug fixes (exit policies):
Avoid disclosing exit outbound bind addresses, configured port bind addresses, and local interface addresses in relay descriptors by default under ExitPolicyRejectPrivate. Instead, only reject these (otherwise unlisted) addresses if ExitPolicyRejectLocalInterfaces is set. Fixes bug 18456; bug fix on 0.2.7.2-alpha. Patch by teor.
Major bug fixes (hidden services):
Allow Tor clients with appropriate controllers to work with FetchHidServDescriptors set to 0. Previously, this option also disabled descriptor cache lookup, thus breaking hidden services entirely. Fixes bug 18704; bug fix on 0.2.0.20-rc. Patch by "twim".
Clients now require hidden services to include the TAP keys for their intro points in the hidden service descriptor. This prevents an inadvertent upgrade to ntor, which a malicious hidden service could use to distinguish clients by consensus version. Fixes bug 20012; bug fix on 0.2.4.8-alpha. Patch by teor.
Major bug fixes (relay, resolver, logging):
For relays that don't know their own address, avoid attempting a local hostname resolve for each descriptor we download. This will cut down on the number of "Success: chose address 'x.x.x.x'" log lines, and also avoid confusing clock jumps if the resolver is slow. Fixes bugs 20423 and 20610; bug fix on 0.2.8.1-alpha.
Minor features (port flags):
Add new flags to the *Port options to give finer control over which requests are allowed. The flags are NoDNSRequest, NoOnionTraffic, and the synthetic flag OnionTrafficOnly, which is equivalent to NoDNSRequest, NoIPv4Traffic, and NoIPv6Traffic. Closes enhancement 18693; patch by "teor".
Minor features (build, hardening):
Detect and work around a libclang_rt problem that would prevent clang from finding __mulodi4() on some 32-bit platforms, and thus keep -ftrapv from linking on those systems. Closes ticket 19079.
When building on a system without runtime support for the runtime hardening options, try to log a useful warning at configuration time, rather than an incomprehensible warning at link time. If expensive hardening was requested, this warning becomes an error. Closes ticket 18895.
Minor features (client, directory):
Since authorities now omit all routers that lack the Running and Valid flags, we assume that any relay listed in the consensus must have those flags. Closes ticket 20001; implements part of proposal 272.
Minor features (code safety):
In our integer-parsing functions, ensure that the maximum value we allow is no smaller than the minimum value. Closes ticket 19063; patch from "U+039b".
Minor features (compilation, portability):
Compile correctly on MacOS 10.12 (aka "Sierra"). Closes ticket 20241.
Minor features (config):
Warn users when descriptor and port addresses are inconsistent. Mitigates bug 13953; patch by teor.
Minor features (controller):
Allow controllers to configure basic client authorization on hidden services when they create them with the ADD_ONION controller command. Implements ticket 15588. Patch by "special".
Fire a STATUS_SERVER controller event whenever the hibernation status changes between "awake"/"soft"/"hard". Closes ticket 18685.
Implement new GETINFO queries for all downloads that use download_status_t to schedule retries. This allows controllers to examine the schedule for pending downloads. Closes ticket 19323.
Minor features (development tools, etags):
Teach the "make tags" Makefile target how to correctly find "MOCK_IMPL" function definitions. Patch from nherring; closes ticket 16869.
Minor features (directory authority):
After voting, if the authorities decide that a relay is not "Valid", they no longer include it in the consensus at all. Closes ticket 20002; implements part of proposal 272.
Directory authorities now only give the Guard flag to a relay if they are also giving it the Stable flag. This change allows us to simplify path selection for clients. It should have minimal effect in practice, since >99% of Guards already have the Stable flag. Implements ticket 18624.
Directory authorities now write their v3-status-votes file out to disk earlier in the consensus process, so we have a record of the votes even if we abort the consensus process. Resolves ticket 19036.
Minor features (fallback directory list, new since 0.2.9.7-rc):
Replace the 81 remaining fallbacks of the 100 originally introduced in Tor 0.2.8.3-alpha in March 2016, with a list of 177 fallbacks (123 new, 54 existing, 27 removed) generated in December 2016. Resolves ticket 20170.
Minor features (hidden service):
Stop being so strict about the payload length of "rendezvous1" cells. We used to be locked in to the "TAP" handshake length, and now we can handle better handshakes like "ntor". Resolves ticket 18998.
Minor features (infrastructure, time):
Tor now includes an improved timer backend, so that we can efficiently support tens or hundreds of thousands of concurrent timers, as will be needed for some of our planned anti-traffic- analysis work. This code is based on William Ahern's "timeout.c" project, which implements a "tickless hierarchical timing wheel". Closes ticket 18365.
Tor now uses the operating system's monotonic timers (where available) for internal fine-grained timing. Previously we would look at the system clock, and then attempt to compensate for the clock running backwards. Closes ticket 18908.
Minor features (logging):
Add a set of macros to check nonfatal assertions, for internal use. Migrating more of our checks to these should help us avoid needless crash bugs. Closes ticket 18613.
Provide a more useful warning message when configured with an invalid Nickname. Closes ticket 18300; patch from "icanhasaccount".
When dumping unparseable router descriptors, optionally store them in separate files, named by digest, up to a configurable size limit. You can change the size limit by setting the MaxUnparseableDescSizeToLog option, and disable this feature by setting that option to 0. Closes ticket 18322.
Minor features (performance):
Change the "optimistic data" extension from "off by default" to "on by default". The default was ordinarily overridden by a consensus option, but when clients were bootstrapping for the first time, they would not have a consensus to get the option from. Changing this default saves a round-trip during startup. Closes ticket 18815.
Minor features (relay, usability):
When the directory authorities refuse a bad relay's descriptor, encourage the relay operator to contact us. Many relay operators won't notice this line in their logs, but it's a win if even a few learn why we don't like what their relay was doing. Resolves ticket 18760.
Minor features (security, TLS):
Servers no longer support clients that lack AES ciphersuites. (3DES is no longer considered an acceptable cipher.) We believe that no such Tor clients currently exist, since Tor has required OpenSSL 0.9.7 or later since 2009. Closes ticket 19998.
Minor features (testing):
Disable memory protections on OpenBSD when performing our unit tests for memwipe(). The test deliberately invokes undefined behavior, and the OpenBSD protections interfere with this. Patch from "rubiate". Closes ticket 20066.
Move the test-network.sh script to chutney, and modify tor's test- network.sh to call the (newer) chutney version when available. Resolves ticket 19116. Patch by teor.
Use the lcov convention for marking lines as unreachable, so that we don't count them when we're generating test coverage data. Update our coverage tools to understand this convention. Closes ticket 16792.
Our link-handshake unit tests now check that when invalid handshakes fail, they fail with the error messages we expected.
Our unit testing code that captures log messages no longer prevents them from being written out if the user asked for them (by passing --debug or --info or --notice or --warn to the "test" binary). This change prevents us from missing unexpected log messages simply because we were looking for others. Related to ticket 19999.
The unit tests now log all warning messages with the "BUG" flag. Previously, they only logged errors by default. This change will help us make our testing code more correct, and make sure that we only hit this code when we mean to. In the meantime, however, there will be more warnings in the unit test logs than before. This is preparatory work for ticket 19999.
The unit tests now treat any failure of a "tor_assert_nonfatal()" assertion as a test failure.
We've done significant work to make the unit tests run faster.
Minor features (testing, ipv6):
Add the hs-ipv6 chutney target to make test-network-all's IPv6 tests. Remove bridges+hs, as it's somewhat redundant. This requires a recent chutney version that supports IPv6 clients, relays, and authorities. Closes ticket 20069; patch by teor.
Add the single-onion and single-onion-ipv6 chutney targets to "make test-network-all". This requires a recent chutney version with the single onion network flavors (git c72a652 or later). Closes ticket 20072; patch by teor.
Minor features (Tor2web):
Make Tor2web clients respect ReachableAddresses. This feature was inadvertently enabled in 0.2.8.6, then removed by bug fix 19973 on 0.2.8.7. Implements feature 20034. Patch by teor.
Minor features (unix domain sockets):
When configuring a unix domain socket for a SocksPort, ControlPort, or Hidden service, you can now wrap the address in quotes, using C-style escapes inside the quotes. This allows unix domain socket paths to contain spaces. Resolves ticket 18753.
Minor features (user interface):
Tor now supports the ability to declare options deprecated, so that we can recommend that people stop using them. Previously, this was done in an ad-hoc way. There is a new --list-deprecated-options command-line option to list all of the deprecated options. Closes ticket 19820.
Minor features (virtual addresses):
Increase the maximum number of bits for the IPv6 virtual network prefix from 16 to 104. In this way, the condition for address allocation is less restrictive. Closes ticket 20151; feature on 0.2.4.7-alpha.
Minor bug fixes (circuits):
Use the CircuitBuildTimeout option whenever LearnCircuitBuildTimeout is disabled. Previously, we would respect the option when a user disabled it, but not when it was disabled because some other option was set. Fixes bug 20073; bug fix on 0.2.4.12-alpha. Patch by teor.
Minor bug fixes (build):
The current Git revision when building from a local repository is now detected correctly when using git worktrees. Fixes bug 20492; bug fix on 0.2.3.9-alpha.
Minor bug fixes (relay address discovery):
Stop reordering IP addresses returned by the OS. This makes it more likely that Tor will guess the same relay IP address every time. Fixes issue 20163; bug fix on 0.2.7.1-alpha, ticket 17027. Reported by René Mayrhofer, patch by "cypherpunks".
Minor bug fixes (memory allocation):
Change how we allocate memory for large chunks on buffers, to avoid a (currently impossible) integer overflow, and to waste less space when allocating unusually large chunks. Fixes bug 20081; bug fix on 0.2.0.16-alpha. Issue identified by Guido Vranken.
Minor bug fixes (bootstrap):
Remember the directory server we fetched the consensus or previous certificates from, and use it to fetch future authority certificates. This change improves bootstrapping performance. Fixes bug 18963; bug fix on 0.2.8.1-alpha.
Minor bug fixes (circuits):
Make sure extend_info_from_router() is only called on servers. Fixes bug 19639; bug fix on 0.2.8.1-alpha.
Minor bug fixes (client, fascistfirewall):
Avoid spurious warnings when ReachableAddresses or FascistFirewall is set. Fixes bug 20306; bug fix on 0.2.8.2-alpha.
Minor bug fixes (client, unix domain sockets):
Disable IsolateClientAddr when using AF_UNIX backed SocksPorts as the client address is meaningless. Fixes bug 20261; bug fix on 0.2.6.3-alpha.
Minor bug fixes (code style):
Fix an integer signedness conversion issue in the case conversion tables. Fixes bug 19168; bug fix on 0.2.1.11-alpha.
Minor bug fixes (compilation):
Build correctly on versions of libevent2 without support for evutil_secure_rng_add_bytes(). Fixes bug 19904; bug fix on 0.2.5.4-alpha.
When building with Clang, use a full set of GCC warnings. (Previously, we included only a subset, because of the way we detected them.) Fixes bug 19216; bug fix on 0.2.0.1-alpha.
Detect Libevent2 functions correctly on systems that provide libevent2, but where libevent1 is linked with -levent. Fixes bug 19904; bug fix on 0.2.2.24-alpha. Patch from Rubiate.
Run correctly when built on Windows build environments that require _vcsprintf(). Fixes bug 20560; bug fix on 0.2.2.11-alpha.
Minor bug fixes (configuration):
When parsing quoted configuration values from the torrc file, handle Windows line endings correctly. Fixes bug 19167; bug fix on 0.2.0.16-alpha. Patch from "Pingl".
Minor bug fixes (directory authority):
Authorities now sort the "package" lines in their votes, for ease of debugging. (They are already sorted in consensus documents.) Fixes bug 18840; bug fix on 0.2.6.3-alpha.
Die with a more useful error when the operator forgets to place the authority_signing_key file into the keys directory. This avoids an uninformative assert & traceback about having an invalid key. Fixes bug 20065; bug fix on 0.2.0.1-alpha.
When allowing private addresses, mark Exits that only exit to private locations as such. Fixes bug 20064; bug fix on 0.2.2.9-alpha.
When parsing a detached signature, make sure we use the length of the digest algorithm instead of a hardcoded DIGEST256_LEN in order to avoid comparing bytes out-of-bounds with a smaller digest length such as SHA1. Fixes bug 19066; bug fix on 0.2.2.6-alpha.
Minor bug fixes (getpass):
Defensively fix a non-triggerable heap corruption at do_getpass() to protect ourselves from mistakes in the future. Fixes bug 19223; bug fix on 0.2.7.3-rc. Bug found by Guido Vranken, patch by nherring.
Minor bug fixes (guard selection):
Don't mark guards as unreachable if connection_connect() fails. That function fails for local reasons, so it shouldn't reveal anything about the status of the guard. Fixes bug 14334; bug fix on 0.2.3.10-alpha.
Use a single entry guard even if the NumEntryGuards consensus parameter is not provided. Fixes bug 17688; bug fix on 0.2.5.6-alpha.
Minor bug fixes (hidden services):
Increase the minimum number of internal circuits we preemptively build from 2 to 3, so a circuit is available when a client connects to another onion service. Fixes bug 13239; bug fix on 0.1.0.1-rc.
Allow hidden services to run on IPv6 addresses even when the IPv6Exit option is not set. Fixes bug 18357; bug fix on 0.2.4.7-alpha.
Stop logging intro point details to the client log on certain error conditions. Fixed as part of bug 20012; bug fix on 0.2.4.8-alpha. Patch by teor.
When deleting an ephemeral hidden service, close its intro points even if they are not completely open. Fixes bug 18604; bug fix on 0.2.7.1-alpha.
When configuring hidden services, check every hidden service directory's permissions. Previously, we only checked the last hidden service. Fixes bug 20529; bug fix on 0.2.6.2-alpha.
Minor bug fixes (IPv6, testing):
Check for IPv6 correctly on Linux when running test networks. Fixes bug 19905; bug fix on 0.2.7.3-rc; patch by teor.
Minor bug fixes (Linux seccomp2 sandbox):
Add permission to run the sched_yield() and sigaltstack() system calls, in order to support versions of Tor compiled with asan or ubsan code that use these calls. Now "sandbox 1" and "--enable-expensive-hardening" should be compatible on more systems. Fixes bug 20063; bug fix on 0.2.5.1-alpha.
Minor bug fixes (logging):
Downgrade a harmless log message about the pending_entry_connections list from "warn" to "info". Mitigates bug 19926.
Log a more accurate message when we fail to dump a microdescriptor. Fixes bug 17758; bug fix on 0.2.2.8-alpha. Patch from Daniel Pinto.
When logging a directory ownership mismatch, log the owning username correctly. Fixes bug 19578; bug fix on 0.2.2.29-beta.
When we are unable to remove the bw_accounting file, do not warn if the reason we couldn't remove it was that it didn't exist. Fixes bug 19964; bug fix on 0.2.5.4-alpha. Patch from pastly.
Minor bug fixes (memory leak):
Fix a series of slow memory leaks related to parsing torrc files and options. Fixes bug 19466; bug fix on 0.2.1.6-alpha.
Avoid a small memory leak when informing worker threads about rotated onion keys. Fixes bug 20401; bug fix on 0.2.6.3-alpha.
Fix a small memory leak when receiving AF_UNIX connections on a SocksPort. Fixes bug 20716; bug fix on 0.2.6.3-alpha.
When moving a signed descriptor object from a source to an existing destination, free the allocated memory inside that destination object. Fixes bug 20715; bug fix on 0.2.8.3-alpha.
Fix a memory leak and use-after-free error when removing entries from the sandbox's getaddrinfo() cache. Fixes bug 20710; bug fix on 0.2.5.5-alpha. Patch from "cypherpunks".
Fix a small, uncommon memory leak that could occur when reading a truncated ed25519 key file. Fixes bug 18956; bug fix on 0.2.6.1-alpha.
Minor bug fixes (option parsing):
Count unix sockets when counting client listeners (SOCKS, Trans, NATD, and DNS). This has no user-visible behavior changes: these options are set once, and never read. Required for correct behavior in ticket 17178. Fixes bug 19677; bug fix on 0.2.6.3-alpha. Patch by teor.
Minor bug fixes (options):
Check the consistency of UseEntryGuards and EntryNodes more reliably. Fixes bug 20074; bug fix on 0.2.4.12-alpha. Patch by teor.
Stop changing the configured value of UseEntryGuards on authorities and Tor2web clients. Fixes bug 20074; bug fix on commits 51fc6799 in 0.1.1.16-rc and acda1735 in 0.2.4.3-alpha. Patch by teor.
Minor bug fixes (relay):
Ensure relays don't make multiple connections during bootstrap. Fixes bug 20591; bug fix on 0.2.8.1-alpha.
Do not try to parallelize workers more than 16x without the user explicitly configuring us to do so, even if we do detect more than 16 CPU cores. Fixes bug 19968; bug fix on 0.2.3.1-alpha.
Minor bug fixes (testing):
The test-stem and test-network makefile targets now depend only on the tor binary that they are testing. Previously, they depended on "make all". Fixes bug 18240; bug fix on 0.2.8.2-alpha. Based on a patch from "cypherpunks".
Allow clients to retry HSDirs much faster in test networks. Fixes bug 19702; bug fix on 0.2.7.1-alpha. Patch by teor.
Avoid a unit test failure on systems with over 16 detectable CPU cores. Fixes bug 19968; bug fix on 0.2.3.1-alpha.
Let backtrace tests work correctly under AddressSanitizer: disable ASAN's detection of segmentation faults while running test_bt.sh, so that we can make sure that our own backtrace generation code works. Fixes bug 18934; bug fix on 0.2.5.2-alpha. Patch from "cypherpunks".
Fix the test-network-all target on out-of-tree builds by using the correct path to the test driver script. Fixes bug 19421; bug fix on 0.2.7.3-rc.
Stop spurious failures in the local interface address discovery unit tests. Fixes bug 20634; bug fix on 0.2.8.1-alpha; patch by Neel Chauhan.
Use ECDHE ciphers instead of ECDH in tortls tests. LibreSSL has removed the ECDH ciphers which caused the tests to fail on platforms which use it. Fixes bug 20460; bug fix on 0.2.8.1-alpha.
The tor_tls_server_info_callback unit test no longer crashes when debug-level logging is turned on. Fixes bug 20041; bug fix on 0.2.8.1-alpha.
Minor bug fixes (time):
Improve overflow checks in tv_udiff and tv_mdiff. Fixes bug 19483; bug fix on all released tor versions.
When computing the difference between two times in milliseconds, we now round to the nearest millisecond correctly. Previously, we could sometimes round in the wrong direction. Fixes bug 19428; bug fix on 0.2.2.2-alpha.
Minor bug fixes (Tor2web):
Prevent Tor2web clients from running hidden services: these services are not anonymous due to the one-hop client paths. Fixes bug 19678. Patch by teor.
Minor bug fixes (user interface):
Display a more accurate number of suppressed messages in the log rate-limiter. Previously, there was a potential integer overflow in the counter. Now, if the number of messages hits a maximum, the rate-limiter doesn't count any further. Fixes bug 19435; bug fix on 0.2.4.11-alpha.
Fix a typo in the passphrase prompt for the ed25519 identity key. Fixes bug 19503; bug fix on 0.2.7.2-alpha.
Code simplification and refactoring:
Remove redundant declarations of the MIN macro. Closes ticket 18889.
Rename tor_dup_addr() to tor_addr_to_str_dup() to avoid confusion. Closes ticket 18462; patch from "icanhasaccount".
Split the 600-line directory_handle_command_get function into separate functions for different URL types. Closes ticket 16698.
Documentation:
Add module-level internal documentation for 36 C files that previously didn't have a high-level overview. Closes ticket 20385.
Correct the IPv6 syntax in our documentation for the VirtualAddrNetworkIPv6 torrc option. Closes ticket 19743.
Correct the minimum bandwidth value in torrc.sample, and queue a corresponding change for torrc.minimal. Closes ticket 20085.
Fix spelling of "--enable-tor2web-mode" in the manpage. Closes ticket 19153. Patch from "U+039b".
Module-level documentation for several more modules. Closes tickets 19287 and 19290.
Document the --passphrase-fd option in the tor manpage. Fixes bug 19504; bug fix on 0.2.7.3-rc.
Document the default PathsNeededToBuildCircuits value that's used by clients when the directory authorities don't set min_paths_for_circs_pct. Fixes bug 20117; bug fix on 0.2.4.10-alpha. Patch by teor, reported by Jesse V.
Fix manual for the User option: it takes a username, not a UID. Fixes bug 19122; bug fix on 0.0.2pre16 (the first version to have a manpage!).
Fix the description of the --passphrase-fd option in the tor-gencert manpage. The option is used to pass the number of a file descriptor to read the passphrase from, not to read the file descriptor from. Fixes bug 19505; bug fix on 0.2.0.20-alpha.
Removed code:
We no longer include the (dead, deprecated) bufferevent code in Tor. Closes ticket 19450. Based on a patch from "U+039b".
Removed features:
Remove support for "GET /tor/bytes.txt" DirPort request, and "GETINFO dir-usage" controller request, which were only available via a compile-time option in Tor anyway. Feature was added in 0.2.2.1-alpha. Resolves ticket 19035.
There is no longer a compile-time option to disable support for TransPort. (If you don't want TransPort, just don't use it.) Patch from "U+039b". Closes ticket 19449.
Testing:
Run more workqueue tests as part of "make check". These had previously been implemented, but you needed to know special command-line options to enable them.
We now have unit tests for our code to reject zlib "compression bombs". (Fortunately, the code works fine.)

New in Tor 0.2.8.11 (Dec 8, 2016)

New in Tor 0.2.8.10 (Dec 3, 2016)

New in Tor 0.2.9.5 Alpha (Nov 8, 2016)

Fixes numerous bugs discovered in the previous alpha version.
Major bugfixes (client performance):
Clients now respond to new application stream requests immediately when they arrive, rather than waiting up to one second before starting to handle them. Fixes part of bug 19969; bugfix on 0.2.8.1-alpha.
Major bugfixes (client reliability):
When Tor leaves standby because of a new application request, open circuits as needed to serve that request. Previously, we would potentially wait a very long time. Fixes part of bug 19969; bugfix on 0.2.8.1-alpha.
Major bugfixes (download scheduling):
When using an exponential backoff schedule, do not give up on downloading just because we have failed a bunch of times. Since each delay is longer than the last, retrying indefinitely won't hurt. Fixes bug 20536; bugfix on 0.2.9.1-alpha.
If a consensus expires while we are waiting for certificates to download, stop waiting for certificates.
If we stop waiting for certificates less than a minute after we started downloading them, do not consider the certificate download failure a separate failure. Fixes bug 20533; bugfix on 0.2.0.9-alpha.
Remove the maximum delay on exponential-backoff scheduling. Since we now allow an infinite number of failures (see ticket 20536), we must now allow the time to grow longer on each failure. Fixes part of bug 20534; bugfix on 0.2.9.1-alpha.
Make our initial download delays closer to those from 0.2.8. Fixes another part of bug 20534; bugfix on 0.2.9.1-alpha.
When determining when to download a directory object, handle times after 2038 if the operating system supports them. (Someday this will be important!) Fixes bug 20587; bugfix on 0.2.8.1-alpha.
When using exponential backoff in test networks, use a lower exponent, so the delays do not vary as much. This helps test networks bootstrap consistently. Fixes bug 20597; bugfix on 20499.
Minor features (geoip):
Update geoip and geoip6 to the November 3 2016 Maxmind GeoLite2 Country database.
Minor bugfixes (client directory scheduling):
Treat "relay too busy to answer request" as a failed request and a reason to back off on our retry frequency. This is safe now that exponential backoffs retry indefinitely, and avoids a bug where we would reset our download schedule erroneously. Fixes bug 20593; bugfix on 0.2.9.1-alpha.
Minor bugfixes (client, logging):
Remove a BUG warning in circuit_pick_extend_handshake(). Instead, assume all nodes support EXTEND2. Use ntor whenever a key is available. Fixes bug 20472; bugfix on 0.2.9.3-alpha.
On DNSPort, stop logging a BUG warning on a failed hostname lookup. Fixes bug 19869; bugfix on 0.2.9.1-alpha.
Minor bugfixes (hidden services):
When configuring hidden services, check every hidden service directory's permissions. Previously, we only checked the last hidden service. Fixes bug 20529; bugfix the work to fix 13942 in 0.2.6.2-alpha.
Minor bugfixes (portability):
Fix compilation with OpenSSL 1.1 and less commonly-used CPU architectures. Closes ticket 20588.
Use ECDHE ciphers instead of ECDH in tortls tests. LibreSSL has removed the ECDH ciphers which caused the tests to fail on platforms which use it. Fixes bug 20460; bugfix on 0.2.8.1-alpha.
Fix implicit conversion warnings under OpenSSL 1.1. Fixes bug 20551; bugfix on 0.2.1.1-alpha.
Minor bugfixes (relay bootstrap):
Ensure relays don't make multiple connections during bootstrap. Fixes bug 20591; bugfix on 0.2.8.1-alpha.
Minor bugfixes (relay):
Work around a memory leak in OpenSSL 1.1 when encoding public keys. Fixes bug 20553; bugfix on 0.0.2pre8.
Avoid a small memory leak when informing worker threads about rotated onion keys. Fixes bug 20401; bugfix on 0.2.6.3-alpha.
Do not try to parallelize workers more than 16x without the user explicitly configuring us to do so, even if we do detect more than 16 CPU cores. Fixes bug 19968; bugfix on 0.2.3.1-alpha.
Minor bugfixes (single onion services):
Start correctly when creating a single onion service in a directory that did not previously exist. Fixes bug 20484; bugfix on 0.2.9.3-alpha.
Minor bugfixes (testing):
Avoid a unit test failure on systems with over 16 detectable CPU cores. Fixes bug 19968; bugfix on 0.2.3.1-alpha.
Documentation:
Clarify that setting HiddenServiceNonAnonymousMode requires you to also set "SOCKSPort 0". Fixes bug 20487; bugfix on 0.2.9.3-alpha.
Module-level documentation for several more modules. Closes tickets 19287 and 19290.

New in Tor 0.2.9.4 Alpha (Oct 18, 2016)

Tor 0.2.9.4-alpha fixes a security hole in previous versions of Tor that would allow a remote attacker to crash a Tor client, hidden service, relay, or authority. All Tor users should upgrade to this version, or to 0.2.8.9. Patches will be released for older versions of Tor.
Tor 0.2.9.4-alpha also adds numerous small features and fix-ups to previous versions of Tor, including the implementation of a feature to future- proof the Tor ecosystem against protocol changes, some bug fixes necessary for Tor Browser to use unix domain sockets correctly, and several portability improvements. We anticipate that this will be the last alpha in the Tor 0.2.9 series, and that the next release will be a release candidate.
Major features (security fixes):
Prevent a class of security bugs caused by treating the contents of a buffer chunk as if they were a NUL-terminated string. At least one such bug seems to be present in all currently used versions of Tor, and would allow an attacker to remotely crash most Tor instances, especially those compiled with extra compiler hardening. With this defense in place, such bugs can't crash Tor, though we should still fix them as they occur. Closes ticket 20384 (TROVE-2016-10-001).
Major features (subprotocol versions):
Tor directory authorities now vote on a set of recommended subprotocol versions, and on a set of required subprotocol versions. Clients and relays that lack support for a _required_ subprotocol version will not start; those that lack support for a _recommended_ subprotocol version will warn the user to upgrade. Closes ticket 19958; implements part of proposal 264.
Tor now uses "subprotocol versions" to indicate compatibility. Previously, versions of Tor looked at the declared Tor version of a relay to tell whether they could use a given feature. Now, they should be able to rely on its declared subprotocol versions. This change allows compatible implementations of the Tor protocol(s) to exist without pretending to be 100% bug-compatible with particular releases of Tor itself. Closes ticket 19958; implements part of proposal 264.
Minor feature (fallback directories):
Remove broken fallbacks from the hard-coded fallback directory list. Closes ticket 20190; patch by teor.
Minor features (client, directory):
Since authorities now omit all routers that lack the Running and Valid flags, we assume that any relay listed in the consensus must have those flags. Closes ticket 20001; implements part of proposal 272.
Minor features (compilation, portability):
Compile correctly on MacOS 10.12 (aka "Sierra"). Closes ticket 20241.
Minor features (development tools, etags):
Teach the "make tags" Makefile target how to correctly find "MOCK_IMPL" function definitions. Patch from nherring; closes ticket 16869.
Minor features (geoip):
Update geoip and geoip6 to the October 4 2016 Maxmind GeoLite2 Country database.
Minor features (unix domain sockets):
When configuring a unix domain socket for a SocksPort, ControlPort, or Hidden service, you can now wrap the address in quotes, using C-style escapes inside the quotes. This allows unix domain socket paths to contain spaces.
Minor features (virtual addresses):
Increase the maximum number of bits for the IPv6 virtual network prefix from 16 to 104. In this way, the condition for address allocation is less restrictive. Closes ticket 20151; feature on 0.2.4.7-alpha.
Minor bugfixes (address discovery):
Stop reordering IP addresses returned by the OS. This makes it more likely that Tor will guess the same relay IP address every time. Fixes issue 20163; bugfix on 0.2.7.1-alpha, ticket 17027. Reported by René Mayrhofer, patch by "cypherpunks".
Minor bugfixes (client, unix domain sockets):
Disable IsolateClientAddr when using AF_UNIX backed SocksPorts as the client address is meaningless. Fixes bug 20261; bugfix on 0.2.6.3-alpha.
Minor bugfixes (compilation, OpenBSD):
Detect Libevent2 functions correctly on systems that provide libevent2, but where libevent1 is linked with -levent. Fixes bug 19904; bugfix on 0.2.2.24-alpha. Patch from Rubiate.
Minor bugfixes (configuration):
When parsing quoted configuration values from the torrc file, handle windows line endings correctly. Fixes bug 19167; bugfix on 0.2.0.16-alpha. Patch from "Pingl".
Minor bugfixes (getpass):
Defensively fix a non-triggerable heap corruption at do_getpass() to protect ourselves from mistakes in the future. Fixes bug #19223; bugfix on 0.2.7.3-rc. Bug found by Guido Vranken, patch by nherring.
Minor bugfixes (hidden service):
Allow hidden services to run on IPv6 addresses even when the IPv6Exit option is not set. Fixes bug 18357; bugfix on 0.2.4.7-alpha.
Documentation:
Add module-level internal documentation for 36 C files that previously didn't have a high-level overview. Closes ticket #20385.
Required libraries:
When building with OpenSSL, Tor now requires version 1.0.1 or later. OpenSSL 1.0.0 and earlier are no longer supported by the OpenSSL team, and should not be used. Closes ticket 20303.

New in Tor 0.2.8.9 (Oct 18, 2016)

New in Tor 0.2.9.3 Alpha (Sep 23, 2016)

Tor 0.2.9.3-alpha adds improved support for entities that want to make high-performance services available through the Tor .onion mechanism without themselves receiving anonymity as they host those services. It also tries harder to ensure that all steps on a circuit are using the strongest crypto possible, strengthens some TLS properties, and resolves several bugs -- including a pair of crash bugs from the 0.2.8 series. Anybody running an earlier version of 0.2.9.x should upgrade.
Major bug fixes (crash, also in 0.2.8.8):
Fix a complicated crash bug that could affect Tor clients configured to use bridges when replacing a networkstatus consensus in which one of their bridges was mentioned. OpenBSD users saw more crashes here, but all platforms were potentially affected. Fixes bug 20103; bugfix on 0.2.8.2-alpha.
Major bug fixes (relay, OOM handler, also in 0.2.8.8):
Fix a timing-dependent assertion failure that could occur when we tried to flush from a circuit after having freed its cells because of an out-of-memory condition. Fixes bug 20203; bugfix on 0.2.8.1-alpha. Thanks to "cypherpunks" for help diagnosing this one.
Major features (circuit building, security):
Authorities, relays and clients now require ntor keys in all descriptors, for all hops (except for rare hidden service protocol cases), for all circuits, and for all other roles. Part of ticket 19163.
Tor authorities, relays, and clients only use ntor, except for rare cases in the hidden service protocol. Part of ticket 19163.
Major features (single-hop "hidden" services):
Add experimental HiddenServiceSingleHopMode and HiddenServiceNonAnonymousMode options. When both are set to 1, every hidden service on a Tor instance becomes a non-anonymous Single Onion Service. Single Onions make one-hop (direct) connections to their introduction and renzedvous points. One-hop circuits make Single Onion servers easily locatable, but clients remain location-anonymous. This is compatible with the existing hidden service implementation, and works on the current tor network without any changes to older relays or clients. Implements proposal 260, completes ticket 17178. Patch by teor and asn.
Major features (resource management):
Tor can now notice it is about to run out of sockets, and preemptively close connections of lower priority. (This feature is off by default for now, since the current prioritizing method is yet not mature enough. You can enable it by setting "DisableOOSCheck 0", but watch out: it might close some sockets you would rather have it keep.) Closes ticket 18640.
Major bug fixes (circuit building):
Hidden service client-to-intro-point and service-to-rendezvous- point cicruits use the TAP key supplied by the protocol, to avoid epistemic attacks. Fixes bug 19163; bugfix on 0.2.4.18-rc.
Major bug fixes (compilation, OpenBSD):
Fix a Libevent-detection bug in our autoconf script that would prevent Tor from linking successfully on OpenBSD. Patch from rubiate. Fixes bug 19902; bugfix on 0.2.9.1-alpha.
Major bug fixes (hidden services):
Clients now require hidden services to include the TAP keys for their intro points in the hidden service descriptor. This prevents an inadvertent upgrade to ntor, which a malicious hidden service could use to distinguish clients by consensus version. Fixes bug 20012; bugfix on 0.2.4.8-alpha. Patch by teor.
Minor features (security, TLS):
Servers no longer support clients that without AES ciphersuites. (3DES is no longer considered an acceptable cipher.) We believe that no such Tor clients currently exist, since Tor has required OpenSSL 0.9.7 or later since 2009. Closes ticket 19998.
Minor feature (fallback directories):
Remove broken entries from the hard-coded fallback directory list. Closes ticket 20190; patch by teor.
Minor features (geoip, also in 0.2.8.8):
Update geoip and geoip6 to the September 6 2016 Maxmind GeoLite2 Country database.
Minor feature (port flags):
Add new flags to the *Port options to finer control over which requests are allowed. The flags are NoDNSRequest, NoOnionTraffic, and the synthetic flag OnionTrafficOnly, which is equivalent to NoDNSRequest, NoIPv4Traffic, and NoIPv6Traffic. Closes enhancement 18693; patch by "teor".
Minor features (directory authority):
After voting, if the authorities decide that a relay is not "Valid", they no longer include it in the consensus at all. Closes ticket 20002; implements part of proposal 272.
Minor features (testing):
Disable memory protections on OpenBSD when performing our unit tests for memwipe(). The test deliberately invokes undefined behavior, and the OpenBSD protections interfere with this. Patch from "rubiate". Closes ticket 20066.
Minor features (testing, ipv6):
Add the single-onion and single-onion-ipv6 chutney targets to "make test-network-all". This requires a recent chutney version with the single onion network flavours (git c72a652 or later). Closes ticket 20072; patch by teor.
Add the hs-ipv6 chutney target to make test-network-all's IPv6 tests. Remove bridges+hs, as it's somewhat redundant. This requires a recent chutney version that supports IPv6 clients, relays, and authorities. Closes ticket 20069; patch by teor.
Minor features (Tor2web):
Make Tor2web clients respect ReachableAddresses. This feature was inadvertently enabled in 0.2.8.6, then removed by bugfix 19973 on 0.2.8.7. Implements feature 20034. Patch by teor.
Minor features (unit tests):
We've done significant work to make the unit tests run faster.
Our link-handshake unit tests now check that when invalid handshakes fail, they fail with the error messages we expected.
Our unit testing code that captures log messages no longer prevents them from being written out if the user asked for them (by passing --debug or --info or or --notice --warn to the "test" binary). This change prevents us from missing unexpected log messages simply because we were looking for others. Related to ticket 19999.
The unit tests now log all warning messages with the "BUG" flag. Previously, they only logged errors by default. This change will help us make our testing code more correct, and make sure that we only hit this code when we mean to. In the meantime, however, there will be more warnings in the unit test logs than before. This is preparatory work for ticket 19999.
The unit tests now treat any failure of a "tor_assert_nonfatal()" assertion as a test failure.
Minor bug fixes (circuits):
Use the CircuitBuildTimeout option whenever LearnCircuitBuildTimeout is disabled. Previously, we would respect the option when a user disabled it, but not when it was disabled because some other option was set. Fixes bug 20073; bugfix on 0.2.4.12-alpha. Patch by teor.
Minor bug fixes (allocation):
Change how we allocate memory for large chunks on buffers, to avoid a (currently impossible) integer overflow, and to waste less space when allocating unusually large chunks. Fixes bug 20081; bugfix on 0.2.0.16-alpha. Issue identified by Guido Vranken.
Always include orconfig.h before including any other C headers. Sometimes, it includes macros that affect the behavior of the standard headers. Fixes bug 19767; bugfix on 0.2.9.1-alpha (the first version to use AC_USE_SYSTEM_EXTENSIONS).
Fix a syntax error in the IF_BUG_ONCE__() macro in non-GCC- compatible compilers. Fixes bug 20141; bugfix on 0.2.9.1-alpha. Patch from Gisle Vanem.
Stop trying to build with Clang 4.0's -Wthread-safety warnings. They apparently require a set of annotations that we aren't currently using, and they create false positives in our pthreads wrappers. Fixes bug 20110; bugfix on 0.2.9.1-alpha.
Minor bug fixes (directory authority):
Die with a more useful error when the operator forgets to place the authority_signing_key file into the keys directory. This avoids an uninformative assert & traceback about having an invalid key. Fixes bug 20065; bugfix on 0.2.0.1-alpha.
When allowing private addresses, mark Exits that only exit to private locations as such. Fixes bug 20064; bugfix on 0.2.2.9-alpha.
Minor bug fixes (documentation):
Document the default PathsNeededToBuildCircuits value that's used by clients when the directory authorities don't set min_paths_for_circs_pct. Fixes bug 20117; bugfix on 02c320916e02 in tor-0.2.4.10-alpha. Patch by teor, reported by Jesse V.
Fix manual for the User option: it takes a username, not a UID. Fixes bug 19122; bugfix on 0.0.2pre16 (the first version to have a manpage!).
Minor bug fixes (hidden services):
Stop logging intro point details to the client log on certain error conditions. Fixed as part of bug 20012; bugfix on 0.2.4.8-alpha. Patch by teor.
Minor bug fixes (IPv6, testing):
Check for IPv6 correctly on Linux when running test networks. Fixes bug 19905; bugfix on 0.2.7.3-rc; patch by teor.
Minor bug fixes (Linux seccomp2 sandbox):
Add permission to run the sched_yield() and sigaltstack() system calls, in order to support versions of Tor compiled with asan or ubsan code that use these calls. Now "sandbox 1" and "--enable-expensive-hardening" should be compatible on more systems. Fixes bug 20063; bugfix on 0.2.5.1-alpha.
Minor bug fixes (logging):
When logging a message from the BUG() macro, be explicit about what we were asserting. Previously we were confusing what we were asserting with what the bug was. Fixes bug 20093; bugfix on 0.2.9.1-alpha.
When we are unable to remove the bw_accounting file, do not warn if the reason we couldn't remove it was that it didn't exist. Fixes bug 19964; bugfix on 0.2.5.4-alpha. Patch from 'pastly'.
Minor bug fixes (option parsing):
Count unix sockets when counting client listeners (SOCKS, Trans, NATD, and DNS). This has no user-visible behaviour changes: these options are set once, and never read. Required for correct behaviour in ticket 17178. Fixes bug 19677; bugfix on 0.2.6.3-alpha. Patch by teor.
Minor bug fixes (options):
Check the consistency of UseEntryGuards and EntryNodes more reliably. Fixes bug 20074; bugfix on tor- 0.2.4.12-alpha. Patch by teor.
Stop changing the configured value of UseEntryGuards on authorities and Tor2web clients. Fixes bug 20074; bugfix on commits 51fc6799 in tor-0.1.1.16-rc and acda1735 in tor-0.2.4.3- alpha. Patch by teor.
Minor bug fixes (Tor2web):
Prevent Tor2web clients running hidden services, these services are not anonymous due to the one-hop client paths. Fixes bug 19678. Patch by teor.
Minor bug fixes (unit tests):
Fix a shared-random unit test that was failing on big endian architectures due to internal representation of a integer copied to a buffer. The test is changed to take a full 32 bytes of data and use the output of a python script that make the COMMIT and REVEAL calculation according to the spec. Fixes bug 19977; bugfix on 0.2.9.1-alpha.
The tor_tls_server_info_callback unit test no longer crashes when debug-level logging is turned on. Fixes bug 20041; bugfix on 0.2.8.1-alpha.

New in Tor 0.2.8.8 (Sep 23, 2016)

New in Tor 0.2.9.2 Alpha (Aug 25, 2016)

Directory authority changes (also in 0.2.8.7):
The "Tonga" bridge authority has been retired; the new bridge authority is "Bifroest". Closes tickets 19728 and 19690.
Major bugfixes (client, security, also in 0.2.8.7):
Only use the ReachableAddresses option to restrict the first hop in a path. In earlier versions of 0.2.8.x, it would apply to every hop in the path, with a possible degradation in anonymity for anyone using an uncommon ReachableAddress setting. Fixes bug 19973; bugfix on 0.2.8.2-alpha.
Major features (user interface):
Tor now supports the ability to declare options deprecated, so that we can recommend that people stop using them. Previously, this was done in an ad-hoc way. Closes ticket 19820.
Major bugfixes (directory downloads):
Avoid resetting download status for consensuses hourly, since we already have another, smarter retry mechanism. Fixes bug 8625; bugfix on 0.2.0.9-alpha.
Minor features (config):
Warn users when descriptor and port addresses are inconsistent. Mitigates bug 13953; patch by teor.
Minor features (geoip):
Update geoip and geoip6 to the August 2 2016 Maxmind GeoLite2 Country database.
Minor features (user interface):
There is a new --list-deprecated-options command-line option to list all of the deprecated options. Implemented as part of ticket 19820.
Minor bugfixes (code style):
Fix an integer signedness conversion issue in the case conversion tables. Fixes bug 19168; bugfix on 0.2.1.11-alpha.
Minor bugfixes (compilation):
Build correctly on versions of libevent2 without support for evutil_secure_rng_add_bytes(). Fixes bug 19904; bugfix on 0.2.5.4-alpha.
Fix a compilation warning on GCC versions before 4.6. Our ENABLE_GCC_WARNING macro used the word "warning" as an argument, when it is also required as an argument to the compiler pragma. Fixes bug 19901; bugfix on 0.2.9.1-alpha.
Minor bugfixes (compilation, also in 0.2.8.7):
Remove an inappropriate "inline" in tortls.c that was causing warnings on older versions of GCC. Fixes bug 19903; bugfix on 0.2.8.1-alpha.
Minor bugfixes (fallback directories, also in 0.2.8.7):
Avoid logging a NULL string pointer when loading fallback directory information. Fixes bug 19947; bugfix on 0.2.4.7-alpha and 0.2.8.1-alpha. Report and patch by "rubiate".
Minor bugfixes (logging):
Log a more accurate message when we fail to dump a microdescriptor. Fixes bug 17758; bugfix on 0.2.2.8-alpha. Patch from Daniel Pinto.
Minor bugfixes (memory leak):
Fix a series of slow memory leaks related to parsing torrc files and options. Fixes bug 19466; bugfix on 0.2.1.6-alpha.
Deprecated features:
A number of DNS-cache-related sub-options for client ports are now deprecated for security reasons, and may be removed in a future version of Tor. (We believe that client-side DNS cacheing is a bad idea for anonymity, and you should not turn it on.) The options are: CacheDNS, CacheIPv4DNS, CacheIPv6DNS, UseDNSCache, UseIPv4Cache, and UseIPv6Cache.
A number of options are deprecated for security reasons, and may be removed in a future version of Tor. The options are: AllowDotExit, AllowInvalidNodes, AllowSingleHopCircuits, AllowSingleHopExits, ClientDNSRejectInternalAddresses, CloseHSClientCircuitsImmediatelyOnTimeout, CloseHSServiceRendCircuitsImmediatelyOnTimeout, ExcludeSingleHopRelays, FastFirstHopPK, TLSECGroup, UseNTorHandshake, and WarnUnsafeSocks.
The *ListenAddress options are now deprecated as unnecessary: the corresponding *Port options should be used instead. These options may someday be removed. The affected options are: ControlListenAddress, DNSListenAddress, DirListenAddress, NATDListenAddress, ORListenAddress, SocksListenAddress, and TransListenAddress.
Documentation:
Correct the IPv6 syntax in our documentation for the VirtualAddrNetworkIPv6 torrc option. Closes ticket 19743.
Removed code:
We no longer include the (dead, deprecated) bufferevent code in Tor. Closes ticket 19450. Based on a patch from U+039b.

New in Tor 0.2.8.7 (Aug 25, 2016)

New in Tor 0.2.8.6 (Aug 3, 2016)

New system requirements:
Tor no longer attempts to support platforms where the "time_t" type is unsigned. (To the best of our knowledge, only OpenVMS does this, and Tor has never actually built on OpenVMS.) Closes ticket 18184.
Tor no longer supports versions of OpenSSL with a broken implementation of counter mode. (This bug was present in OpenSSL 1.0.0, and was fixed in OpenSSL 1.0.0a.) Tor still detects, but no longer runs with, these versions.
Tor now uses Autoconf version 2.63 or later, and Automake 1.11 or later (released in 2008 and 2009 respectively). If you are building Tor from the git repository instead of from the source distribution, and your tools are older than this, you will need to upgrade. Closes ticket 17732.
Directory authority changes:
Update the V3 identity key for the dannenberg directory authority: it was changed on 18 November 2015. Closes task 17906. Patch by teor.
Urras is no longer a directory authority. Closes ticket 19271.
Major features (directory system):
Include a trial list of default fallback directories, based on an opt-in survey of suitable relays. Doing this should make clients bootstrap more quickly and reliably, and reduce the load on the directory authorities. Closes ticket 15775. Patch by teor. Candidates identified using an OnionOO script by weasel, teor, gsathya, and karsten.
Previously only relays that explicitly opened a directory port (DirPort) accepted directory requests from clients. Now all relays, with and without a DirPort, accept and serve tunneled directory requests that they receive through their ORPort. You can disable this behavior using the new DirCache option. Closes ticket 12538.
When bootstrapping multiple consensus downloads at a time, use the first one that starts downloading, and close the rest. This reduces failures when authorities or fallback directories are slow or down. Together with the code for feature 15775, this feature should reduces failures due to fallback churn. Implements ticket 4483. Patch by teor. Implements IPv4 portions of proposal 210 by mikeperry and teor.
Major features (security, Linux):
When Tor starts as root on Linux and is told to switch user ID, it can now retain the capability to bind to low ports. By default, Tor will do this only when it's switching user ID and some low ports have been configured. You can change this behavior with the new option KeepBindCapabilities. Closes ticket 8195.
Major bugfixes (client, bootstrapping):
Check if bootstrap consensus downloads are still needed when the linked connection attaches. This prevents tor making unnecessary begindir-style connections, which are the only directory connections tor clients make since the fix for 18483 was merged.
Fix some edge cases where consensus download connections may not have been closed, even though they were not needed. Related to fix for 18809.
Make relays retry consensus downloads the correct number of times, rather than the more aggressive client retry count. Fixes part of ticket 18809.
Major bugfixes (dns proxy mode, crash):
Avoid crashing when running as a DNS proxy. Fixes bug 16248; bugfix on 0.2.0.1-alpha. Patch from "cypherpunks".
Major bugfixes (ed25519, voting):
Actually enable support for authorities to match routers by their Ed25519 identities. Previously, the code had been written, but some debugging code that had accidentally been left in the codebase made it stay turned off. Fixes bug 17702; bugfix on 0.2.7.2-alpha.
When collating votes by Ed25519 identities, authorities now include a "NoEdConsensus" flag if the ed25519 value (or lack thereof) for a server does not reflect the majority consensus. Related to bug 17668; bugfix on 0.2.7.2-alpha.
When generating a vote with keypinning disabled, never include two entries for the same ed25519 identity. This bug was causing authorities to generate votes that they could not parse when a router violated key pinning by changing its RSA identity but keeping its Ed25519 identity. Fixes bug 17668; fixes part of bug 18318. Bugfix on 0.2.7.2-alpha.
Major bugfixes (key management):
If OpenSSL fails to generate an RSA key, do not retain a dangling pointer to the previous (uninitialized) key value. The impact here should be limited to a difficult-to-trigger crash, if OpenSSL is running an engine that makes key generation failures possible, or if OpenSSL runs out of memory. Fixes bug 19152; bugfix on 0.2.1.10-alpha. Found by Yuan Jochen Kang, Suman Jana, and Baishakhi Ray.
Major bugfixes (security, client, DNS proxy):
Stop a crash that could occur when a client running with DNSPort received a query with multiple address types, and the first address type was not supported. Found and fixed by Scott Dial. Fixes bug 18710; bugfix on 0.2.5.4-alpha.
Major bugfixes (security, compilation):
Correctly detect compiler flags on systems where _FORTIFY_SOURCE is predefined. Previously, our use of -D_FORTIFY_SOURCE would cause a compiler warning, thereby making other checks fail, and needlessly disabling compiler-hardening support. Fixes one case of bug 18841; bugfix on 0.2.3.17-beta. Patch from "trudokal".
Repair hardened builds under the clang compiler. Previously, our use of _FORTIFY_SOURCE would conflict with clang's address sanitizer. Fixes bug 14821; bugfix on 0.2.5.4-alpha.
Major bugfixes (security, pointers):
Avoid a difficult-to-trigger heap corruption attack when extending a smartlist to contain over 16GB of pointers. Fixes bug 18162; bugfix on 0.1.1.11-alpha, which fixed a related bug incompletely. Reported by Guido Vranken.
Major bugfixes (testing):
Fix a bug that would block 'make test-network-all' on systems where IPv6 packets were lost. Fixes bug 19008; bugfix on 0.2.7.3-rc.
Major bugfixes (user interface):
Correctly give a warning in the cases where a relay is specified by nickname, and one such relay is found, but it is not officially Named. Fixes bug 19203; bugfix on 0.2.3.1-alpha.
Minor features (accounting):
Added two modes to the AccountingRule option: One for limiting only the number of bytes sent ("AccountingRule out"), and one for limiting only the number of bytes received ("AccountingRule in"). Closes ticket 15989; patch from "unixninja92".
Minor features (bug-resistance):
Make Tor survive errors involving connections without a corresponding event object. Previously we'd fail with an assertion; now we produce a log message. Related to bug 16248.
Use tor_snprintf() and tor_vsnprintf() even in external and low- level code, to harden against accidental failures to NUL- terminate. Part of ticket 17852. Patch from jsturgix. Found with Flawfinder.
Minor features (build):
Detect systems with FreeBSD-derived kernels (such as GNU/kFreeBSD) as having possible IPFW support. Closes ticket 18448. Patch from Steven Chamberlain.
Since our build process now uses "make distcheck", we no longer force "make dist" to depend on "make check". Closes ticket 17893; patch from "cypherpunks".
Tor now builds once again with the recent OpenSSL 1.1 development branch (tested against 1.1.0-pre5 and 1.1.0-pre6-dev). We have been tracking OpenSSL 1.1 development as it has progressed, and fixing numerous compatibility issues as they arose. See tickets 17549, 17921, 17984, 19499, and 18286.
When building manual pages, set the timezone to "UTC", so that the output is reproducible. Fixes bug 19558; bugfix on 0.2.2.9-alpha. Patch from intrigeri.
Minor features (clients):
Make clients, onion services, and bridge relays always use an encrypted begindir connection for directory requests. Resolves ticket 18483. Patch by teor.
Minor features (controller):
Add 'GETINFO exit-policy/reject-private/[default,relay]', so controllers can examine the the reject rules added by ExitPolicyRejectPrivate. This makes it easier for stem to display exit policies.
Adds the FallbackDir entries to 'GETINFO config/defaults'. Closes tickets 16774 and 17817. Patch by George Tankersley.
New 'GETINFO hs/service/desc/id/' command to retrieve a hidden service descriptor from a service's local hidden service descriptor cache. Closes ticket 14846.
Minor features (crypto):
Add SHA3 and SHAKE support to crypto.c. Closes ticket 17783.
Add SHA512 support to crypto.c. Closes ticket 17663; patch from George Tankersley.
Improve performance when hashing non-multiple of 8 sized buffers, based on Andrew Moon's public domain SipHash-2-4 implementation. Fixes bug 17544; bugfix on 0.2.5.3-alpha.
Validate the hard-coded Diffie-Hellman parameters and ensure that p is a safe prime, and g is a suitable generator. Closes ticket 18221.
When allocating a digest state object, allocate no more space than we actually need. Previously, we would allocate as much space as the state for the largest algorithm would need. This change saves up to 672 bytes per circuit. Closes ticket 17796.
Minor features (directory downloads):
Add UseDefaultFallbackDirs, which enables any hard-coded fallback directory mirrors. The default is 1; set it to 0 to disable fallbacks. Implements ticket 17576. Patch by teor.
Wait for busy authorities and fallback directories to become non- busy when bootstrapping. (A similar change was made in 6c443e987d for directory caches chosen from the consensus.) Closes ticket 17864; patch by teor.
Minor features (geoip):
Update geoip and geoip6 to the July 6 2016 Maxmind GeoLite2 Country database.
Minor features (hidden service directory):
Streamline relay-side hsdir handling: when relays consider whether to accept an uploaded hidden service descriptor, they no longer check whether they are one of the relays in the network that is "supposed" to handle that descriptor. Implements ticket 18332.
Minor features (IPv6):
Add ClientPreferIPv6DirPort, which is set to 0 by default. If set to 1, tor prefers IPv6 directory addresses.
Add ClientUseIPv4, which is set to 1 by default. If set to 0, tor avoids using IPv4 for client OR and directory connections.
Add address policy assume_action support for IPv6 addresses.
Add an argument 'ipv6=address:orport' to the DirAuthority and FallbackDir torrc options, to specify an IPv6 address for an authority or fallback directory. Add hard-coded ipv6 addresses for directory authorities that have them. Closes ticket 17327; patch from Nick Mathewson and teor.
Allow users to configure directory authorities and fallback directory servers with IPv6 addresses and ORPorts. Resolves ticket 6027.
Limit IPv6 mask bits to 128.
Make tor_ersatz_socketpair work on IPv6-only systems. Fixes bug 17638; bugfix on 0.0.2pre8. Patch by teor.
Try harder to obey the IP version restrictions "ClientUseIPv4 0", "ClientUseIPv6 0", "ClientPreferIPv6ORPort", and "ClientPreferIPv6DirPort". Closes ticket 17840; patch by teor.
Warn when comparing against an AF_UNSPEC address in a policy, it's almost always a bug. Closes ticket 17863; patch by teor.
routerset_parse now accepts IPv6 literal addresses. Fixes bug 17060; bugfix on 0.2.1.3-alpha. Patch by teor.
Minor features (Linux seccomp2 sandbox):
Reject attempts to change our Address with "Sandbox 1" enabled. Changing Address with Sandbox turned on would never actually work, but previously it would fail in strange and confusing ways. Found while fixing 18548.
Minor features (logging):
When logging to syslog, allow a tag to be added to the syslog identity (the string prepended to every log message). The tag can be configured with SyslogIdentityTag and defaults to none. Setting it to "foo" will cause logs to be tagged as "Tor-foo". Closes ticket 17194.
Minor features (portability):
Use timingsafe_memcmp() where available. Closes ticket 17944; patch from .
Minor features (relay, address discovery):
Add a family argument to get_interface_addresses_raw() and subfunctions to make network interface address interogation more efficient. Now Tor can specifically ask for IPv4, IPv6 or both types of interfaces from the operating system. Resolves ticket 17950.
When get_interface_address6_list(.,AF_UNSPEC,.) is called and fails to enumerate interface addresses using the platform-specific API, have it rely on the UDP socket fallback technique to try and find out what IP addresses (both IPv4 and IPv6) our machine has. Resolves ticket 17951.
Minor features (replay cache):
The replay cache now uses SHA256 instead of SHA1. Implements feature 8961. Patch by teor, issue reported by rransom.
Minor features (robustness):
Exit immediately with an error message if the code attempts to use Libevent without having initialized it. This should resolve some frequently-made mistakes in our unit tests. Closes ticket 18241.
Minor features (security, clock):
Warn when the system clock appears to move back in time (when the state file was last written in the future). Tor doesn't know that consensuses have expired if the clock is in the past. Patch by teor. Implements ticket 17188.
Minor features (security, exit policies):
ExitPolicyRejectPrivate now rejects more private addresses by default. Specifically, it now rejects the relay's outbound bind addresses (if configured), and the relay's configured port addresses (such as ORPort and DirPort). Fixes bug 17027; bugfix on 0.2.0.11-alpha. Patch by teor.
Minor features (security, memory erasure):
Make memwipe() do nothing when passed a NULL pointer or buffer of zero size. Check size argument to memwipe() for underflow. Fixes bug 18089; bugfix on 0.2.3.25 and 0.2.4.6-alpha. Reported by "gk", patch by teor.
Set the unused entries in a smartlist to NULL. This helped catch a (harmless) bug, and shouldn't affect performance too much. Implements ticket 17026.
Use SecureMemoryWipe() function to securely clean memory on Windows. Previously we'd use OpenSSL's OPENSSL_cleanse() function. Implements feature 17986.
Use explicit_bzero or memset_s when present. Previously, we'd use OpenSSL's OPENSSL_cleanse() function. Closes ticket 7419; patches from and .
Minor features (security, RNG):
Adjust Tor's use of OpenSSL's RNG APIs so that they absolutely, positively are not allowed to fail. Previously we depended on internal details of OpenSSL's behavior. Closes ticket 17686.
Never use the system entropy output directly for anything besides seeding the PRNG. When we want to generate important keys, instead of using system entropy directly, we now hash it with the PRNG stream. This may help resist certain attacks based on broken OS entropy implementations. Closes part of ticket 17694.
Use modern system calls (like getentropy() or getrandom()) to generate strong entropy on platforms that have them. Closes ticket 13696.
Minor features (security, win32):
Set SO_EXCLUSIVEADDRUSE on Win32 to avoid a local port-stealing attack. Fixes bug 18123; bugfix on all tor versions. Patch by teor.
Minor features (unix domain sockets):
Add a new per-socket option, RelaxDirModeCheck, to allow creating Unix domain sockets without checking the permissions on the parent directory. (Tor checks permissions by default because some operating systems only check permissions on the parent directory. However, some operating systems do look at permissions on the socket, and tor's default check is unneeded.) Closes ticket 18458. Patch by weasel.
Minor features (unix file permissions):
Defer creation of Unix sockets until after setuid. This avoids needing CAP_CHOWN and CAP_FOWNER when using systemd's CapabilityBoundingSet, or chown and fowner when using SELinux. Implements part of ticket 17562. Patch from Jamie Nguyen.
If any directory created by Tor is marked as group readable, the filesystem group is allowed to be either the default GID or the root user. Allowing root to read the DataDirectory prevents the need for CAP_READ_SEARCH when using systemd's CapabilityBoundingSet, or dac_read_search when using SELinux. Implements part of ticket 17562. Patch from Jamie Nguyen.
Introduce a new DataDirectoryGroupReadable option. If it is set to 1, the DataDirectory will be made readable by the default GID. Implements part of ticket 17562. Patch from Jamie Nguyen.
Minor bugfixes (accounting):
The max bandwidth when using 'AccountRule sum' is now correctly logged. Fixes bug 18024; bugfix on 0.2.6.1-alpha. Patch from "unixninja92".
Minor bugfixes (assert, portability):
Fix an assertion failure in memarea.c on systems where "long" is shorter than the size of a pointer. Fixes bug 18716; bugfix on 0.2.1.1-alpha.
Minor bugfixes (bootstrap):
Consistently use the consensus download schedule for authority certificates. Fixes bug 18816; bugfix on 0.2.4.13-alpha.
Minor bugfixes (build):
Avoid spurious failures from configure files related to calling exit(0) in TOR_SEARCH_LIBRARY. Fixes bug 18625; bugfix on 0.2.0.1-alpha. Patch from "cypherpunks".
Do not link the unit tests against both the testing and non- testing versions of the static libraries. Fixes bug 18490; bugfix on 0.2.7.1-alpha.
Resolve warnings when building on systems that are concerned with signed char. Fixes bug 18728; bugfix on 0.2.7.2-alpha and 0.2.6.1-alpha.
Silence spurious clang-scan warnings in the ed25519_donna code by explicitly initializing some objects. Fixes bug 18384; bugfix on 0.2.7.2-alpha. Patch by teor.
When libscrypt.h is found, but no libscrypt library can be linked, treat libscrypt as absent. Fixes bug 19161; bugfix on 0.2.6.1-alpha.
Cause the unit tests to compile correctly on mingw64 versions that lack sscanf. Fixes bug 19213; bugfix on 0.2.7.1-alpha.
Don't try to use the pthread_condattr_setclock() function unless it actually exists. Fixes compilation on NetBSD-6.x. Fixes bug 17819; bugfix on 0.2.6.3-alpha.
Fix backtrace compilation on FreeBSD. Fixes bug 17827; bugfix on 0.2.5.2-alpha.
Fix search for libevent libraries on OpenBSD (and other systems that install libevent 1 and libevent 2 in parallel). Fixes bug 16651; bugfix on 0.1.0.7-rc. Patch from "rubiate".
Isolate environment variables meant for tests from the rest of the build system. Fixes bug 17818; bugfix on 0.2.7.3-rc.
Mark all object files that include micro-revision.i as depending on it, so as to make parallel builds more reliable. Fixes bug 17826; bugfix on 0.2.5.1-alpha.
Remove config.log only from make distclean, not from make clean. Fixes bug 17924; bugfix on 0.2.4.1-alpha.
Replace usage of 'INLINE' with 'inline'. Fixes bug 17804; bugfix on 0.0.2pre8.
Remove an #endif from configure.ac so that we correctly detect the presence of in6_addr.s6_addr32. Fixes bug 17923; bugfix on 0.2.0.13-alpha.
Minor bugfixes (client, bootstrap):
Count receipt of new microdescriptors as progress towards bootstrapping. Previously, with EntryNodes set, Tor might not successfully repopulate the guard set on bootstrapping. Fixes bug 16825; bugfix on 0.2.3.1-alpha.
Minor bugfixes (code correctness):
Fix a bad memory handling bug that would occur if we had queued a cell on a channel's incoming queue. Fortunately, we can't actually queue a cell like that as our code is constructed today, but it's best to avoid this kind of error, even if there isn't any code that triggers it today. Fixes bug 18570; bugfix on 0.2.4.4-alpha.
Assert that allocated memory held by the reputation code is freed according to its internal counters. Fixes bug 17753; bugfix on 0.1.1.1-alpha.
Assert when the TLS contexts fail to initialize. Fixes bug 17683; bugfix on 0.0.6.
Update to the latest version of Trunnel, which tries harder to avoid generating code that can invoke memcpy(p,NULL,0). Bug found by clang address sanitizer. Fixes bug 18373; bugfix on 0.2.7.2-alpha.
When closing an entry connection, generate a warning if we should have sent an end cell for it but we haven't. Fixes bug 17876; bugfix on 0.2.3.2-alpha.
Minor bugfixes (configuration):
Fix a tiny memory leak when parsing a port configuration ending in ":auto". Fixes bug 18374; bugfix on 0.2.3.3-alpha.
Minor bugfixes (containers):
If we somehow attempt to construct a heap with more than 1073741822 elements, avoid an integer overflow when maintaining the heap property. Fixes bug 18296; bugfix on 0.1.2.1-alpha.
Minor bugfixes (controller, microdescriptors):
Make GETINFO dir/status-vote/current/consensus conform to the control specification by returning "551 Could not open cached consensus..." when not caching consensuses. Fixes bug 18920; bugfix on 0.2.2.6-alpha.
Minor bugfixes (crypto):
Check the return value of HMAC() and assert on failure. Fixes bug 17658; bugfix on 0.2.3.6-alpha. Patch by teor.
Minor bugfixes (directories):
When fetching extrainfo documents, compare their SHA256 digests and Ed25519 signing key certificates with the routerinfo that led us to fetch them, rather than with the most recent routerinfo. Otherwise we generate many spurious warnings about mismatches. Fixes bug 17150; bugfix on 0.2.7.2-alpha.
When generating a URL for a directory server on an IPv6 address, wrap the IPv6 address in square brackets. Fixes bug 18051; bugfix on 0.2.3.9-alpha. Patch from Malek.
Minor bugfixes (downloading):
Predict more correctly whether we'll be downloading over HTTP when we determine the maximum length of a URL. This should avoid a "BUG" warning about the Squid HTTP proxy and its URL limits. Fixes bug 19191.
Minor bugfixes (exit policies, security):
Refresh an exit relay's exit policy when interface addresses change. Previously, tor only refreshed the exit policy when the configured external address changed. Fixes bug 18208; bugfix on 0.2.7.3-rc. Patch by teor.
Minor bugfixes (fallback directories):
Mark fallbacks as "too busy" when they return a 503 response, rather than just marking authorities. Fixes bug 17572; bugfix on 0.2.4.7-alpha. Patch by teor.
When requesting extrainfo descriptors from a trusted directory server, check whether it is an authority or a fallback directory which supports extrainfo descriptors. Fixes bug 18489; bugfix on 0.2.4.7-alpha. Reported by atagar, patch by teor.
Minor bugfixes (hidden service, client):
Handle the case where the user makes several fast consecutive requests to the same .onion address. Previously, the first six requests would each trigger a descriptor fetch, each picking a directory (there are 6 overall) and the seventh one would fail because no directories were left, thereby triggering a close on all current directory connections asking for the hidden service. The solution here is to not close the connections if we have pending directory fetches. Fixes bug 15937; bugfix on 0.2.7.1-alpha.
Minor bugfixes (hidden service, control port):
Add the onion address to the HS_DESC event for the UPLOADED action both on success or failure. It was previously hardcoded with UNKNOWN. Fixes bug 16023; bugfix on 0.2.7.2-alpha.
Minor bugfixes (hidden service, directory):
Bridges now refuse "rendezvous2" (hidden service descriptor) publish attempts. Suggested by ticket 18332.
Minor bugfixes (IPv6):
Update the limits in max_dl_per_request for IPv6 address length. Fixes bug 17573; bugfix on 0.2.1.5-alpha.
Minor bugfixes (Linux seccomp2 sandbox):
Allow more syscalls when running with "Sandbox 1" enabled: sysinfo, getsockopt(SO_SNDBUF), and setsockopt(SO_SNDBUFFORCE). On some systems, these are required for Tor to start. Fixes bug 18397; bugfix on 0.2.5.1-alpha. Patch from Daniel Pinto.
Allow IPPROTO_UDP datagram sockets when running with "Sandbox 1", so that get_interface_address6_via_udp_socket_hack() can work. Fixes bug 19660; bugfix on 0.2.5.1-alpha.
Allow the setrlimit syscall, and the prlimit and prlimit64 syscalls, which some libc implementations use under the hood. Fixes bug 15221; bugfix on 0.2.5.1-alpha.
Avoid a 10-second delay when starting as a client with "Sandbox 1" enabled and no DNS resolvers configured. This should help TAILS start up faster. Fixes bug 18548; bugfix on 0.2.5.1-alpha.
Fix a crash when using offline master ed25519 keys with the Linux seccomp2 sandbox enabled. Fixes bug 17675; bugfix on 0.2.7.3-rc.
Allow statistics to be written to disk when "Sandbox 1" is enabled. Fixes bugs 19556 and 19957; bugfix on 0.2.5.1-alpha and 0.2.6.1-alpha respectively.
Minor bugfixes (logging):
In log messages that include a function name, use __FUNCTION__ instead of __PRETTY_FUNCTION__. In GCC, these are synonymous, but with clang __PRETTY_FUNCTION__ has extra information we don't need. Fixes bug 16563; bugfix on 0.0.2pre8. Fix by Tom van der Woerdt.
Remove needless quotes from a log message about unparseable addresses. Fixes bug 17843; bugfix on 0.2.3.3-alpha.
Scrub service name in "unrecognized service ID" log messages. Fixes bug 18600; bugfix on 0.2.4.11-alpha.
When logging information about an unparsable networkstatus vote or consensus, do not say "vote" when we mean consensus. Fixes bug 18368; bugfix on 0.2.0.8-alpha.
When we can't generate a signing key because OfflineMasterKey is set, do not imply that we should have been able to load it. Fixes bug 18133; bugfix on 0.2.7.2-alpha.
When logging a malformed hostname received through socks4, scrub it if SafeLogging says we should. Fixes bug 17419; bugfix on 0.1.1.16-rc.
Minor bugfixes (memory safety):
Avoid freeing an uninitialized pointer when opening a socket fails in get_interface_addresses_ioctl(). Fixes bug 18454; bugfix on 0.2.3.11-alpha. Reported by toralf and "cypherpunks", patch by teor.
Fix a memory leak in "tor --list-fingerprint". Fixes part of bug 18672; bugfix on 0.2.5.1-alpha.
Fix a memory leak in tor-gencert. Fixes part of bug 18672; bugfix on 0.2.0.1-alpha.
Minor bugfixes (pluggable transports):
Avoid reporting a spurious error when we decide that we don't need to terminate a pluggable transport because it has already exited. Fixes bug 18686; bugfix on 0.2.5.5-alpha.
Minor bugfixes (pointer arithmetic):
Fix a bug in memarea_alloc() that could have resulted in remote heap write access, if Tor had ever passed an unchecked size to memarea_alloc(). Fortunately, all the sizes we pass to memarea_alloc() are pre-checked to be less than 128 kilobytes. Fixes bug 19150; bugfix on 0.2.1.1-alpha. Bug found by Guido Vranken.
Minor bugfixes (private directory):
Prevent a race condition when creating private directories. Fixes part of bug 17852; bugfix on 0.0.2pre13. Part of ticket 17852. Patch from jsturgix. Found with Flawfinder.
Minor bugfixes (relays):
Check that both the ORPort and DirPort (if present) are reachable before publishing a relay descriptor. Otherwise, relays publish a descriptor with DirPort 0 when the DirPort reachability test takes longer than the ORPort reachability test. Fixes bug 18050; bugfix on 0.1.0.1-rc. Reported by "starlight", patch by teor.
Resolve some edge cases where we might launch an ORPort reachability check even when DisableNetwork is set. Noticed while fixing bug 18616; bugfix on 0.2.3.9-alpha.
Minor bugfixes (relays, hidden services):
Refuse connection requests to private OR addresses unless ExtendAllowPrivateAddresses is set. Previously, tor would connect, then refuse to send any cells to a private address. Fixes bugs 17674 and 8976; bugfix on 0.2.3.21-rc. Patch by teor.
Minor bugfixes (security, hidden services):
Prevent hidden services connecting to client-supplied rendezvous addresses that are reserved as internal or multicast. Fixes bug 8976; bugfix on 0.2.3.21-rc. Patch by dgoulet and teor.
Minor bugfixes (statistics):
Consistently check for overflow in round_*_to_next_multiple_of functions, and add unit tests with additional and maximal values. Fixes part of bug 13192; bugfix on 0.2.2.1-alpha.
Handle edge cases in the laplace functions: avoid division by zero, avoid taking the log of zero, and silence clang type conversion warnings using round and trunc. Add unit tests for edge cases with maximal values. Fixes part of bug 13192; bugfix on 0.2.6.2-alpha.
We now include consensus downloads via IPv6 in our directory- request statistics. Fixes bug 18460; bugfix on 0.2.3.14-alpha.
Minor bugfixes (test networks, IPv6):
Allow internal IPv6 addresses in descriptors in test networks. Fixes bug 17153; bugfix on 0.2.3.16-alpha. Patch by teor, reported by karsten.
Minor bugfixes (testing):
Check the full results of SHA256 and SHA512 digests in the unit tests. Bugfix on 0.2.2.4-alpha. Patch by teor.
Fix a memory leak in the ntor test. Fixes bug 17778; bugfix on 0.2.4.8-alpha.
Fix a small memory leak that would occur when the TestingEnableCellStatsEvent option was turned on. Fixes bug 18673; bugfix on 0.2.5.2-alpha.
Make unit tests pass on IPv6-only systems, and systems without localhost addresses (like some FreeBSD jails). Fixes bug 17632; bugfix on 0.2.7.3-rc. Patch by teor.
The test for log_heartbeat was incorrectly failing in timezones with non-integer offsets. Instead of comparing the end of the time string against a constant, compare it to the output of format_local_iso_time when given the correct input. Fixes bug 18039; bugfix on 0.2.5.4-alpha.
We no longer disable assertions in the unit tests when coverage is enabled. Instead, we require you to say --disable-asserts-in-tests to the configure script if you need assertions disabled in the unit tests (for example, if you want to perform branch coverage). Fixes bug 18242; bugfix on 0.2.7.1-alpha.
Minor bugfixes (time handling):
When correcting a corrupt 'struct tm' value, fill in the tm_wday field. Otherwise, our unit tests crash on Windows. Fixes bug 18977; bugfix on 0.2.2.25-alpha.
Avoid overflow in tor_timegm when parsing dates in and after 2038 on platforms with 32-bit time_t. Fixes bug 18479; bugfix on 0.0.2pre14. Patch by teor.
Minor bugfixes (tor-gencert):
Correctly handle the case where an authority operator enters a passphrase but sends an EOF before sending a newline. Fixes bug 17443; bugfix on 0.2.0.20-rc. Found by junglefowl.
Code simplification and refactoring:
Clean up a little duplicated code in crypto_expand_key_material_TAP(). Closes ticket 17587; patch from "pfrankw".
Decouple the list of streams waiting to be attached to circuits from the overall connection list. This change makes it possible to attach streams quickly while simplifying Tor's callgraph and avoiding O(N) scans of the entire connection list. Closes ticket 17590.
Extract the more complicated parts of circuit_mark_for_close() into a new function that we run periodically before circuits are freed. This change removes more than half of the functions currently in the "blob". Closes ticket 17218.
Move logging of redundant policy entries in policies_parse_exit_policy_internal into its own function. Closes ticket 17608; patch from "juce".
Quote all the string interpolations in configure.ac -- even those which we are pretty sure can't contain spaces. Closes ticket 17744. Patch from zerosion.
Remove code for configuring OpenSSL dynamic locks; OpenSSL doesn't use them. Closes ticket 17926.
Remove specialized code for non-inplace AES_CTR. 99% of our AES is inplace, so there's no need to have a separate implementation for the non-inplace code. Closes ticket 18258. Patch from Malek.
Simplify return types for some crypto functions that can't actually fail. Patch from Hassan Alsibyani. Closes ticket 18259.
When a direct directory request fails immediately on launch, instead of relaunching that request from inside the code that launches it, instead mark the connection for teardown. This change simplifies Tor's callback and prevents the directory-request launching code from invoking itself recursively. Closes ticket 17589.
Documentation:
Add a description of the correct use of the '--keygen' command- line option. Closes ticket 17583; based on text by 's7r'.
Change build messages to refer to "Fedora" instead of "Fedora Core", and "dnf" instead of "yum". Closes tickets 18459 and 18426. Patches from "icanhasaccount" and "cypherpunks".
Document the contents of the 'datadir/keys' subdirectory in the manual page. Closes ticket 17621.
Document the minimum HeartbeatPeriod value. Closes ticket 15638.
Explain actual minima for BandwidthRate. Closes ticket 16382.
Fix a minor formatting typo in the manpage. Closes ticket 17791.
Mention torspec URL in the manpage and point the reader to it whenever we mention a document that belongs in torspce. Fixes issue 17392.
Stop recommending use of nicknames to identify relays in our MapAddress documentation. Closes ticket 18312.
Removed features:
Remove client-side support for connecting to Tor relays running versions of Tor before 0.2.3.6-alpha. These relays didn't support the v3 TLS handshake protocol, and are no longer allowed on the Tor network. Implements the client side of ticket 11150. Based on patches by Tom van der Woerdt.
We no longer maintain an internal freelist in memarea.c. Allocators should be good enough to make this code unnecessary, and it's doubtful that it ever had any performance benefit.
Testing:
Add unit tests to check for common RNG failure modes, such as returning all zeroes, identical values, or incrementing values (OpenSSL's rand_predictable feature). Patch by teor.
Always test both ed25519 backends, so that we can be sure that our batch-open replacement code works. Part of ticket 16794.
Cover dns_resolve_impl() in dns.c with unit tests. Implements a portion of ticket 16831.
Fix several warnings from clang's address sanitizer produced in the unit tests.
Log more information when the backtrace tests fail. Closes ticket 17892. Patch from "cypherpunks."
More unit tests for compat_libevent.c, procmon.c, tortls.c, util_format.c, directory.c, and options_validate.c. Closes tickets 17075, 17082, 17084, 17003, and 17076 respectively. Patches from Ola Bini.
Treat backtrace test failures as expected on FreeBSD until we solve bug 17808. Closes ticket 18204.
Unit tests for directory_handle_command_get. Closes ticket 17004. Patch from Reinaldo de Souza Jr.

New in Tor 0.2.8.5 RC (Jul 8, 2016)

Tor 0.2.8.5-rc is the second release candidate in the Tor 0.2.8 series. If we find no new bugs or regressions here, the first stable 0.2.8 release will be identical to it. It has a few small bug fixes against previous versions.
Directory authority changes:
Urras is no longer a directory authority. Closes ticket 19271.
Major bug fixes (heartbeat):
Fix a regression that would crash Tor when the periodic "heartbeat" log messages were disabled. Fixes bug 19454; bugfix on tor-0.2.8.1-alpha. Reported by "kubaku".
Minor features (build):
Tor now again builds with the recent OpenSSL 1.1 development branch (tested against 1.1.0-pre6-dev). Closes ticket 19499.
When building manual pages, set the timezone to "UTC", so that the output is reproducible. Fixes bug 19558; bugfix on 0.2.2.9-alpha. Patch from intrigeri.
Minor bug fixes (fallback directory selection):
Avoid errors during fallback selection if there are no eligible fallbacks. Fixes bug 19480; bugfix on 0.2.8.3-alpha. Patch by teor.
Minor bug fixes (IPv6, microdescriptors):
Don't check node addresses when we only have a routerstatus. This allows IPv6-only clients to bootstrap by fetching microdescriptors from fallback directory mirrors. (The microdescriptor consensus has no IPv6 addresses in it.) Fixes bug 19608; bugfix on 0.2.8.2-alpha.
Minor bug fixes (logging):
Reduce pointlessly verbose log messages when directory servers can't be found. Fixes bug 18849; bugfix on 0.2.8.3-alpha and 0.2.8.1-alpha. Patch by teor.
When a fallback directory changes its fingerprint from the hard- coded fingerprint, log a less severe, more explanatory log message. Fixes bug 18812; bugfix on 0.2.8.1-alpha. Patch by teor.
Minor bug fixes (Linux seccomp2 sandboxing):
Allow statistics to be written to disk when "Sandbox 1" is enabled. Fixes bugs 19556 and 19957; bugfix on 0.2.5.1-alpha and 0.2.6.1-alpha respectively.
Minor bug fixes (user interface):
Remove a warning message "Service [scrubbed] not found after descriptor upload". This message appears when one uses HSPOST control command to upload a service descriptor. Since there is only a descriptor and no service, showing this message is pointless and confusing. Fixes bug 19464; bugfix on 0.2.7.2-alpha.
Fallback directory list:
Add a comment to the generated fallback directory list that explains how to comment out unsuitable fallbacks in a way that's compatible with the stem fallback parser.
Update fallback whitelist and blacklist based on relay operator emails. Blacklist unsuitable (non-working, over-volatile) fallbacks. Resolves ticket 19071. Patch by teor.
Update hard-coded fallback list to remove unsuitable fallbacks. Resolves ticket 19071. Patch by teor.

New in Tor 0.2.8.4 RC (Jun 15, 2016)

New in Tor 0.2.8.3 Alpha (May 27, 2016)

Tor 0.2.8.3-alpha resolves several bugs, most of them introduced over the course of the 0.2.8 development cycle. It improves the behavior of directory clients, fixes several crash bugs, fixes a gap in compiler hardening, and allows the full integration test suite to run on more platforms.
Major bugfixes (security, client, DNS proxy):
Stop a crash that could occur when a client running with DNSPort received a query with multiple address types, and the first address type was not supported. Found and fixed by Scott Dial. Fixes bug 18710; bugfix on 0.2.5.4-alpha.
Major bugfixes (security, compilation):
Correctly detect compiler flags on systems where _FORTIFY_SOURCE is predefined. Previously, our use of -D_FORTIFY_SOURCE would cause a compiler warning, thereby making other checks fail, and needlessly disabling compiler-hardening support. Fixes one case of bug 18841; bugfix on 0.2.3.17-beta. Patch from "trudokal".
Major bugfixes (security, directory authorities):
Fix a crash and out-of-bounds write during authority voting, when the list of relays includes duplicate ed25519 identity keys. Fixes bug 19032; bugfix on 0.2.8.2-alpha.
Major bugfixes (client, bootstrapping):
Check if bootstrap consensus downloads are still needed when the linked connection attaches. This prevents tor making unnecessary begindir-style connections, which are the only directory connections tor clients make since the fix for 18483 was merged.
Fix some edge cases where consensus download connections may not have been closed, even though they were not needed. Related to fix for 18809.
Make relays retry consensus downloads the correct number of times, rather than the more aggressive client retry count. Fixes part of ticket 18809.
Stop downloading consensuses when we have a consensus, even if we don't have all the certificates for it yet. Fixes bug 18809; bugfix on 0.2.8.1-alpha. Patches by arma and teor.
Major bugfixes (directory mirrors):
Decide whether to advertise begindir support in the the same way we decide whether to advertise our DirPort. Allowing these decisions to become out-of-sync led to surprising behavior like advertising begindir support when hibernation made us not advertise a DirPort. Resolves bug 18616; bugfix on 0.2.8.1-alpha. Patch by teor.
Major bugfixes (IPv6 bridges, client):
Actually use IPv6 addresses when selecting directory addresses for IPv6 bridges. Fixes bug 18921; bugfix on 0.2.8.1-alpha. Patch by "teor".
Major bugfixes (key management):
If OpenSSL fails to generate an RSA key, do not retain a dangling pointer to the previous (uninitialized) key value. The impact here should be limited to a difficult-to-trigger crash, if OpenSSL is running an engine that makes key generation failures possible, or if OpenSSL runs out of memory. Fixes bug 19152; bugfix on 0.2.1.10-alpha. Found by Yuan Jochen Kang, Suman Jana, and Baishakhi Ray.
Major bugfixes (testing):
Fix a bug that would block 'make test-network-all' on systems where IPv6 packets were lost. Fixes bug 19008; bugfix on tor-0.2.7.3-rc.
Avoid "WSANOTINITIALISED" warnings in the unit tests. Fixes bug 18668; bugfix on 0.2.8.1-alpha.
Minor features (clients):
Make clients, onion services, and bridge relays always use an encrypted begindir connection for directory requests. Resolves ticket 18483. Patch by "teor".
Minor features (fallback directory mirrors):
Give each fallback the same weight for client selection; restrict fallbacks to one per operator; report fallback directory detail changes when rebuilding list; add new fallback directory mirrors to the whitelist; update fallback directories based on the latest OnionOO data; and any other minor simplifications and fixes. Closes tasks 17158, 17905, 18749, bug 18689, and fixes part of bug 18812 on 0.2.8.1-alpha; patch by "teor".
Minor features (geoip):
Update geoip and geoip6 to the May 4 2016 Maxmind GeoLite2 Country database.
Minor bugfixes (assert, portability):
Fix an assertion failure in memarea.c on systems where "long" is shorter than the size of a pointer. Fixes bug 18716; bugfix on 0.2.1.1-alpha.
Minor bugfixes (bootstrap):
Consistently use the consensus download schedule for authority certificates. Fixes bug 18816; bugfix on 0.2.4.13-alpha.
Minor bugfixes (build):
Remove a pair of redundant AM_CONDITIONAL declarations from configure.ac. Fixes one final case of bug 17744; bugfix on 0.2.8.2-alpha.
Resolve warnings when building on systems that are concerned with signed char. Fixes bug 18728; bugfix on 0.2.7.2-alpha and 0.2.6.1-alpha.
When libscrypt.h is found, but no libscrypt library can be linked, treat libscrypt as absent. Fixes bug 19161; bugfix on 0.2.6.1-alpha.
Minor bugfixes (client):
Turn all TestingClientBootstrap* into non-testing torrc options. This changes simply renames them by removing "Testing" in front of them and they do not require TestingTorNetwork to be enabled anymore. Fixes bug 18481; bugfix on 0.2.8.1-alpha.
Make directory node selection more reliable, mainly for IPv6-only clients and clients with few reachable addresses. Fixes bug 18929; bugfix on 0.2.8.1-alpha. Patch by "teor".
Minor bugfixes (controller, microdescriptors):
Make GETINFO dir/status-vote/current/consensus conform to the control specification by returning "551 Could not open cached consensus..." when not caching consensuses. Fixes bug 18920; bugfix on 0.2.2.6-alpha.
Minor bugfixes (crypto, portability):
The SHA3 and SHAKE routines now produce the correct output on Big Endian systems. No code calls either algorithm yet, so this is primarily a build fix. Fixes bug 18943; bugfix on 0.2.8.1-alpha.
Tor now builds again with the recent OpenSSL 1.1 development branch (tested against 1.1.0-pre4 and 1.1.0-pre5-dev). Closes ticket 18286.
Minor bugfixes (directories):
When fetching extrainfo documents, compare their SHA256 digests and Ed25519 signing key certificates with the routerinfo that led us to fetch them, rather than with the most recent routerinfo. Otherwise we generate many spurious warnings about mismatches. Fixes bug 17150; bugfix on 0.2.7.2-alpha.
Minor bugfixes (logging):
When we can't generate a signing key because OfflineMasterKey is set, do not imply that we should have been able to load it. Fixes bug 18133; bugfix on 0.2.7.2-alpha.
Stop periodic_event_dispatch() from blasting twelve lines per second at loglevel debug. Fixes bug 18729; fix on 0.2.8.1-alpha.
When rejecting a misformed INTRODUCE2 cell, only log at PROTOCOL_WARN severity. Fixes bug 18761; bugfix on 0.2.8.2-alpha.
Minor bugfixes (pluggable transports):
Avoid reporting a spurious error when we decide that we don't need to terminate a pluggable transport because it has already exited. Fixes bug 18686; bugfix on 0.2.5.5-alpha.
Minor bugfixes (pointer arithmetic):
Fix a bug in memarea_alloc() that could have resulted in remote heap write access, if Tor had ever passed an unchecked size to memarea_alloc(). Fortunately, all the sizes we pass to memarea_alloc() are pre-checked to be less than 128 kilobytes. Fixes bug 19150; bugfix on 0.2.1.1-alpha. Bug found by Guido Vranken.
Minor bugfixes (relays):
Consider more config options when relays decide whether to regenerate their descriptor. Fixes more of bug 12538; bugfix on 0.2.8.1-alpha.
Resolve some edge cases where we might launch an ORPort reachability check even when DisableNetwork is set. Noticed while fixing bug 18616; bugfix on 0.2.3.9-alpha.
Minor bugfixes (statistics):
We now include consensus downloads via IPv6 in our directory- request statistics. Fixes bug 18460; bugfix on 0.2.3.14-alpha.
Minor bugfixes (testing):
Allow directories in small networks to bootstrap by skipping DirPort checks when the consensus has no exits. Fixes bug 19003; bugfix on 0.2.8.1-alpha. Patch by teor.
Fix a small memory leak that would occur when the TestingEnableCellStatsEvent option was turned on. Fixes bug 18673; bugfix on 0.2.5.2-alpha.
Minor bugfixes (time handling):
When correcting a corrupt 'struct tm' value, fill in the tm_wday field. Otherwise, our unit tests crash on Windows. Fixes bug 18977; bugfix on 0.2.2.25-alpha.
Documentation:
Document the contents of the 'datadir/keys' subdirectory in the manual page. Closes ticket 17621.
Stop recommending use of nicknames to identify relays in our MapAddress documentation. Closes ticket 18312.

New in Tor 0.2.8.2 Alpha (Mar 28, 2016)

Tor 0.2.8.2-alpha is the second alpha in its series. It fixes numerous bugs in earlier versions of Tor, including some that prevented authorities using Tor 0.2.7.x from running correctly. IPv6 and directory support should also be much improved.
New system requirements:
Tor no longer supports versions of OpenSSL with a broken implementation of counter mode. (This bug was present in OpenSSL 1.0.0, and was fixed in OpenSSL 1.0.0a.) Tor still detects, but no longer runs with, these versions.
Tor no longer attempts to support platforms where the "time_t" type is unsigned. (To the best of our knowledge, only OpenVMS does this, and Tor has never actually built on OpenVMS.) Closes ticket 18184.
Tor now uses Autoconf version 2.63 or later, and Automake 1.11 or later (released in 2008 and 2009 respectively). If you are building Tor from the git repository instead of from the source distribution, and your tools are older than this, you will need to upgrade. Closes ticket 17732.
Major bug fixes (security, pointers):
Avoid a difficult-to-trigger heap corruption attack when extending a smartlist to contain over 16GB of pointers. Fixes bug 18162; bugfix on 0.1.1.11-alpha, which fixed a related bug incompletely. Reported by Guido Vranken.
Major bug fixes (bridges, pluggable transports):
Modify the check for OR connections to private addresses. Allow bridges on private addresses, including pluggable transports that ignore the (potentially private) address in the bridge line. Fixes bug 18517; bugfix on 0.2.8.1-alpha. Reported by gk, patch by teor.
Major bug fixes (compilation):
Repair hardened builds under the clang compiler. Previously, our use of _FORTIFY_SOURCE would conflict with clang's address sanitizer. Fixes bug 14821; bugfix on 0.2.5.4-alpha.
Major bug fixes (crash on shutdown):
Correctly handle detaching circuits from muxes when shutting down. Fixes bug 18116; bugfix on 0.2.8.1-alpha.
Fix an assert-on-exit bug related to counting memory usage in rephist.c. Fixes bug 18651; bugfix on 0.2.8.1-alpha.
Major bug fixes (crash on startup):
Fix a segfault during startup: If a Unix domain socket was configured as listener (such as a ControlSocket or a SocksPort "unix:" socket), and tor was started as root but not configured to switch to another user, tor would segfault while trying to string compare a NULL value. Fixes bug 18261; bugfix on 0.2.8.1-alpha. Patch by weasel.
Major bug fixes (dns proxy mode, crash):
Avoid crashing when running as a DNS proxy. Fixes bug 16248; bugfix on 0.2.0.1-alpha. Patch from "cypherpunks".
Major bug fixes (relays, bridge clients):
Ensure relays always allow IPv4 OR and Dir connections. Ensure bridge clients use the address configured in the bridge line. Fixes bug 18348; bugfix on 0.2.8.1-alpha. Reported by sysrqb, patch by teor.
Major bug fixes (voting):
Actually enable support for authorities to match routers by their Ed25519 identities. Previously, the code had been written, but some debugging code that had accidentally been left in the codebase made it stay turned off. Fixes bug 17702; bugfix on 0.2.7.2-alpha.
When collating votes by Ed25519 identities, authorities now include a "NoEdConsensus" flag if the ed25519 value (or lack thereof) for a server does not reflect the majority consensus. Related to bug 17668; bugfix on 0.2.7.2-alpha.
When generating a vote with keypinning disabled, never include two entries for the same ed25519 identity. This bug was causing authorities to generate votes that they could not parse when a router violated key pinning by changing its RSA identity but keeping its Ed25519 identity. Fixes bug 17668; fixes part of bug 18318. Bugfix on 0.2.7.2-alpha.
Minor features (security, win32):
Set SO_EXCLUSIVEADDRUSE on Win32 to avoid a local port-stealing attack. Fixes bug 18123; bugfix on all tor versions. Patch by teor.
Minor features (bug-resistance):
Make Tor survive errors involving connections without a corresponding event object. Previously we'd fail with an assertion; now we produce a log message. Related to bug 16248.
Minor features (build):
Detect systems with FreeBSD-derived kernels (such as GNU/kFreeBSD) as having possible IPFW support. Closes ticket 18448. Patch from Steven Chamberlain.
Minor features (code hardening):
Use tor_snprintf() and tor_vsnprintf() even in external and low- level code, to harden against accidental failures to NUL- terminate. Part of ticket 17852. Patch from jsturgix. Found with Flawfinder.
Minor features (crypto):
Validate the hard-coded Diffie-Hellman parameters and ensure that p is a safe prime, and g is a suitable generator. Closes ticket 18221.
Minor features (geoip):
Update geoip and geoip6 to the March 3 2016 Maxmind GeoLite2 Country database.
Minor features (hidden service directory):
Streamline relay-side hsdir handling: when relays consider whether to accept an uploaded hidden service descriptor, they no longer check whether they are one of the relays in the network that is "supposed" to handle that descriptor. Implements ticket 18332.
Minor features (IPv6):
Add ClientPreferIPv6DirPort, which is set to 0 by default. If set to 1, tor prefers IPv6 directory addresses.
Add ClientUseIPv4, which is set to 1 by default. If set to 0, tor avoids using IPv4 for client OR and directory connections.
Try harder to obey the IP version restrictions "ClientUseIPv4 0", "ClientUseIPv6 0", "ClientPreferIPv6ORPort", and "ClientPreferIPv6DirPort". Closes ticket 17840; patch by teor.
Minor features (linux seccomp2 sandbox):
Reject attempts to change our Address with "Sandbox 1" enabled. Changing Address with Sandbox turned on would never actually work, but previously it would fail in strange and confusing ways. Found while fixing 18548.
Minor features (robustness):
Exit immediately with an error message if the code attempts to use Libevent without having initialized it. This should resolve some frequently-made mistakes in our unit tests. Closes ticket 18241.
Minor features (unix domain sockets):
Add a new per-socket option, RelaxDirModeCheck, to allow creating Unix domain sockets without checking the permissions on the parent directory. (Tor checks permissions by default because some operating systems only check permissions on the parent directory. However, some operating systems do look at permissions on the socket, and tor's default check is unneeded.) Closes ticket 18458. Patch by weasel.
Minor bug fixes (exit policies, security):
Refresh an exit relay's exit policy when interface addresses change. Previously, tor only refreshed the exit policy when the configured external address changed. Fixes bug 18208; bugfix on 0.2.7.3-rc. Patch by teor.
Minor bug fixes (security, hidden services):
Prevent hidden services connecting to client-supplied rendezvous addresses that are reserved as internal or multicast. Fixes bug 8976; bugfix on 0.2.3.21-rc. Patch by dgoulet and teor.
Minor bug fixes (build):
Do not link the unit tests against both the testing and non- testing versions of the static libraries. Fixes bug 18490; bugfix on 0.2.7.1-alpha.
Avoid spurious failures from configure files related to calling exit(0) in TOR_SEARCH_LIBRARY. Fixes bug 18625; bugfix on 0.2.0.1-alpha. Patch from "cypherpunks".
Silence spurious clang-scan warnings in the ed25519_donna code by explicitly initializing some objects. Fixes bug 18384; bugfix on 0.2.7.2-alpha. Patch by teor.
Minor bug fixes (client, bootstrap):
Count receipt of new microdescriptors as progress towards bootstrapping. Previously, with EntryNodes set, Tor might not successfully repopulate the guard set on bootstrapping. Fixes bug 16825; bugfix on 0.2.3.1-alpha.
Minor bug fixes (code correctness):
Update to the latest version of Trunnel, which tries harder to avoid generating code that can invoke memcpy(p,NULL,0). Bug found by clang address sanitizer. Fixes bug 18373; bugfix on 0.2.7.2-alpha.
Minor bug fixes (configuration):
Fix a tiny memory leak when parsing a port configuration ending in ":auto". Fixes bug 18374; bugfix on 0.2.3.3-alpha.
Minor bug fixes (containers):
If we somehow attempt to construct a heap with more than 1073741822 elements, avoid an integer overflow when maintaining the heap property. Fixes bug 18296; bugfix on 0.1.2.1-alpha.
Minor bug fixes (correctness):
Fix a bad memory handling bug that would occur if we had queued a cell on a channel's incoming queue. Fortunately, we can't actually queue a cell like that as our code is constructed today, but it's best to avoid this kind of error, even if there isn't any code that triggers it today. Fixes bug 18570; bugfix on 0.2.4.4-alpha.
Minor bug fixes (directory):
When generating a URL for a directory server on an IPv6 address, wrap the IPv6 address in square brackets. Fixes bug 18051; bugfix on 0.2.3.9-alpha. Patch from Malek.
Minor bug fixes (fallback directory mirrors):
When requesting extrainfo descriptors from a trusted directory server, check whether it is an authority or a fallback directory which supports extrainfo descriptors. Fixes bug 18489; bugfix on 0.2.4.7-alpha. Reported by atagar, patch by teor.
Minor bug fixes (hidden service, client):
Handle the case where the user makes several fast consecutive requests to the same .onion address. Previously, the first six requests would each trigger a descriptor fetch, each picking a directory (there are 6 overall) and the seventh one would fail because no directories were left, thereby triggering a close on all current directory connections asking for the hidden service. The solution here is to not close the connections if we have pending directory fetches. Fixes bug 15937; bugfix on 0.2.7.1-alpha.
Minor bug fixes (hidden service, control port):
Add the onion address to the HS_DESC event for the UPLOADED action both on success or failure. It was previously hardcoded with UNKNOWN. Fixes bug 16023; bugfix on 0.2.7.2-alpha.
Minor bug fixes (hidden service, directory):
Bridges now refuse "rendezvous2" (hidden service descriptor) publish attempts. Suggested by ticket 18332.
Minor bug fixes (linux seccomp2 sandbox):
Allow the setrlimit syscall, and the prlimit and prlimit64 syscalls, which some libc implementations use under the hood. Fixes bug 15221; bugfix on 0.2.5.1-alpha.
Avoid a 10-second delay when starting as a client with "Sandbox 1" enabled and no DNS resolvers configured. This should help TAILS start up faster. Fixes bug 18548; bugfix on 0.2.5.1-alpha.
Fix the sandbox's interoperability with unix domain sockets under setuid. Fixes bug 18253; bugfix on 0.2.8.1-alpha.
Minor bug fixes (logging):
When logging information about an unparsable networkstatus vote or consensus, do not say "vote" when we mean consensus. Fixes bug 18368; bugfix on 0.2.0.8-alpha.
Scrub service name in "unrecognized service ID" log messages. Fixes bug 18600; bugfix on 0.2.4.11-alpha.
Downgrade logs and backtraces about IP versions to info-level. Only log backtraces once each time tor runs. Assists in diagnosing bug 18351; bugfix on 0.2.8.1-alpha. Reported by sysrqb and Christian, patch by teor.
Minor bug fixes (memory safety):
Avoid freeing an uninitialized pointer when opening a socket fails in get_interface_addresses_ioctl(). Fixes bug 18454; bugfix on 0.2.3.11-alpha. Reported by toralf and "cypherpunks", patch by teor.
Correctly duplicate addresses in get_interface_address6_list(). Fixes bug 18454; bugfix on 0.2.8.1-alpha. Reported by toralf, patch by "cypherpunks".
Fix a memory leak in tor-gencert. Fixes part of bug 18672; bugfix on 0.2.0.1-alpha.
Fix a memory leak in "tor --list-fingerprint". Fixes part of bug 18672; bugfix on 0.2.5.1-alpha.
Minor bug fixes (private directory):
Prevent a race condition when creating private directories. Fixes part of bug 17852; bugfix on 0.0.2pre13. Part of ticket 17852. Patch from jsturgix. Found with Flawfinder.
Minor bug fixes (test networks, IPv6):
Allow internal IPv6 addresses in descriptors in test networks. Fixes bug 17153; bugfix on 0.2.3.16-alpha. Patch by teor, reported by karsten.
Minor bug fixes (testing):
We no longer disable assertions in the unit tests when coverage is enabled. Instead, we require you to say --disable-asserts-in-tests to the configure script if you need assertions disabled in the unit tests (for example, if you want to perform branch coverage). Fixes bug 18242; bugfix on 0.2.7.1-alpha.
Minor bug fixes (time parsing):
Avoid overflow in tor_timegm when parsing dates in and after 2038 on platforms with 32-bit time_t. Fixes bug 18479; bugfix on 0.0.2pre14. Patch by teor.
Minor bug fixes (tor-gencert):
Correctly handle the case where an authority operator enters a passphrase but sends an EOF before sending a newline. Fixes bug 17443; bugfix on 0.2.0.20-rc. Found by junglefowl.
Code simplification and refactoring:
Quote all the string interpolations in configure.ac -- even those which we are pretty sure can't contain spaces. Closes ticket 17744. Patch from zerosion.
Remove specialized code for non-inplace AES_CTR. 99% of our AES is inplace, so there's no need to have a separate implementation for the non-inplace code. Closes ticket 18258. Patch from Malek.
Simplify return types for some crypto functions that can't actually fail. Patch from Hassan Alsibyani. Closes ticket 18259.
Documentation:
Change build messages to refer to "Fedora" instead of "Fedora Core", and "dnf" instead of "yum". Closes tickets 18459 and 18426. Patches from "icanhasaccount" and "cypherpunks".
Removed features:
We no longer maintain an internal freelist in memarea.c. Allocators should be good enough to make this code unnecessary, and it's doubtful that it ever had any performance benefit.
Testing:
Fix several warnings from clang's address sanitizer produced in the unit tests.
Treat backtrace test failures as expected on FreeBSD until we solve bug 17808. Closes ticket 18204.

New in Tor 0.2.8.1 Alpha (Feb 5, 2016)

Major features (security, Linux):
When Tor starts as root on Linux and is told to switch user ID, it can now retain the capability to bind to low ports. By default, Tor will do this only when it's switching user ID and some low ports have been configured. You can change this behavior with the new option KeepBindCapabilities. Closes ticket 8195.
Major features (directory system):
When bootstrapping multiple consensus downloads at a time, use the first one that starts downloading, and close the rest. This reduces failures when authorities or fallback directories are slow or down. Together with the code for feature 15775, this feature should reduces failures due to fallback churn. Implements ticket 4483. Patch by "teor". Implements IPv4 portions of proposal 210 by "mikeperry" and "teor".
Include a trial list of default fallback directories, based on an opt-in survey of suitable relays. Doing this should make clients bootstrap more quickly and reliably, and reduce the load on the directory authorities. Closes ticket 15775. Patch by "teor". Candidates identified using an OnionOO script by "weasel", "teor", "gsathya", and "karsten".
Previously only relays that explicitly opened a directory port (DirPort) accepted directory requests from clients. Now all relays, with and without a DirPort, accept and serve tunneled directory requests that they receive through their ORPort. You can disable this behavior using the new DirCache option. Closes ticket 12538.
Major key updates:
Update the V3 identity key for the dannenberg directory authority: it was changed on 18 November 2015. Closes task 17906. Patch by "teor".
Minor features (security, clock):
Warn when the system clock appears to move back in time (when the state file was last written in the future). Tor doesn't know that consensuses have expired if the clock is in the past. Patch by "teor". Implements ticket 17188.
Minor features (security, exit policies):
ExitPolicyRejectPrivate now rejects more private addresses by default. Specifically, it now rejects the relay's outbound bind addresses (if configured), and the relay's configured port addresses (such as ORPort and DirPort). Fixes bug 17027; bugfix on 0.2.0.11-alpha. Patch by "teor".
Minor features (security, memory erasure):
Set the unused entries in a smartlist to NULL. This helped catch a (harmless) bug, and shouldn't affect performance too much. Implements ticket 17026.
Use SecureMemoryWipe() function to securely clean memory on Windows. Previously we'd use OpenSSL's OPENSSL_cleanse() function. Implements feature 17986.
Use explicit_bzero or memset_s when present. Previously, we'd use OpenSSL's OPENSSL_cleanse() function. Closes ticket 7419; patches from and .
Make memwipe() do nothing when passed a NULL pointer or buffer of zero size. Check size argument to memwipe() for underflow. Fixes bug 18089; bugfix on 0.2.3.25 and 0.2.4.6-alpha. Reported by "gk", patch by "teor".
Minor features (security, RNG):
Adjust Tor's use of OpenSSL's RNG APIs so that they absolutely, positively are not allowed to fail. Previously we depended on internal details of OpenSSL's behavior. Closes ticket 17686.
Never use the system entropy output directly for anything besides seeding the PRNG. When we want to generate important keys, instead of using system entropy directly, we now hash it with the PRNG stream. This may help resist certain attacks based on broken OS entropy implementations. Closes part of ticket 17694.
Use modern system calls (like getentropy() or getrandom()) to generate strong entropy on platforms that have them. Closes ticket 13696.
Minor features (accounting):
Added two modes to the AccountingRule option: One for limiting only the number of bytes sent ("AccountingRule out"), and one for limiting only the number of bytes received ("AccountingRule in"). Closes ticket 15989; patch from "unixninja92".
Minor features (build):
Since our build process now uses "make distcheck", we no longer force "make dist" to depend on "make check". Closes ticket 17893; patch from "cypherpunks."
Tor now builds successfully with the recent OpenSSL 1.1 development branch, and with the latest LibreSSL. Closes tickets 17549, 17921, and 17984.
Minor features (controller):
Adds the FallbackDir entries to 'GETINFO config/defaults'. Closes tickets 16774 and 17817. Patch by George Tankersley.
New 'GETINFO hs/service/desc/id/' command to retrieve a hidden service descriptor from a service's local hidden service descriptor cache. Closes ticket 14846.
Add 'GETINFO exit-policy/reject-private/[default,relay]', so controllers can examine the the reject rules added by ExitPolicyRejectPrivate. This makes it easier for stem to display exit policies.
Minor features (crypto):
Add SHA512 support to crypto.c. Closes ticket 17663; patch from George Tankersley.
Add SHA3 and SHAKE support to crypto.c. Closes ticket 17783.
When allocating a digest state object, allocate no more space than we actually need. Previously, we would allocate as much space as the state for the largest algorithm would need. This change saves up to 672 bytes per circuit. Closes ticket 17796.
Improve performance when hashing non-multiple of 8 sized buffers, based on Andrew Moon's public domain SipHash-2-4 implementation. Fixes bug 17544; bugfix on 0.2.5.3-alpha.
Minor features (directory downloads):
Wait for busy authorities and fallback directories to become non- busy when bootstrapping. (A similar change was made in 6c443e987d for directory caches chosen from the consensus.) Closes ticket 17864; patch by "teor".
Add UseDefaultFallbackDirs, which enables any hard-coded fallback directory mirrors. The default is 1; set it to 0 to disable fallbacks. Implements ticket 17576. Patch by "teor".
Minor features (geoip):
Update geoip and geoip6 to the January 5 2016 Maxmind GeoLite2 Country database.
Minor features (IPv6):
Add an argument 'ipv6=address:orport' to the DirAuthority and FallbackDir torrc options, to specify an IPv6 address for an authority or fallback directory. Add hard-coded ipv6 addresses for directory authorities that have them. Closes ticket 17327; patch from Nick Mathewson and "teor".
Add address policy assume_action support for IPv6 addresses.
Limit IPv6 mask bits to 128.
Warn when comparing against an AF_UNSPEC address in a policy, it's almost always a bug. Closes ticket 17863; patch by "teor".
Allow users to configure directory authorities and fallback directory servers with IPv6 addresses and ORPorts. Resolves ticket 6027.
routerset_parse now accepts IPv6 literal addresses. Fixes bug 17060; bugfix on 0.2.1.3-alpha. Patch by "teor".
Make tor_ersatz_socketpair work on IPv6-only systems. Fixes bug 17638; bugfix on 0.0.2pre8. Patch by "teor".
Minor features (logging):
When logging to syslog, allow a tag to be added to the syslog identity (the string prepended to every log message). The tag can be configured with SyslogIdentityTag and defaults to none. Setting it to "foo" will cause logs to be tagged as "Tor-foo". Closes ticket 17194.
Minor features (portability):
Use timingsafe_memcmp() where available. Closes ticket 17944; patch from .
Minor features (relay, address discovery):
Add a family argument to get_interface_addresses_raw() and subfunctions to make network interface address interogation more efficient. Now Tor can specifically ask for IPv4, IPv6 or both types of interfaces from the operating system. Resolves ticket 17950.
When get_interface_address6_list(.,AF_UNSPEC,.) is called and fails to enumerate interface addresses using the platform-specific API, have it rely on the UDP socket fallback technique to try and find out what IP addresses (both IPv4 and IPv6) our machine has. Resolves ticket 17951.
Minor features (replay cache):
The replay cache now uses SHA256 instead of SHA1. Implements feature 8961. Patch by "teor", issue reported by "rransom".
Minor features (unix file permissions):
Defer creation of Unix sockets until after setuid. This avoids needing CAP_CHOWN and CAP_FOWNER when using systemd's CapabilityBoundingSet, or chown and fowner when using SELinux. Implements part of ticket 17562. Patch from Jamie Nguyen.
If any directory created by Tor is marked as group readable, the filesystem group is allowed to be either the default GID or the root user. Allowing root to read the DataDirectory prevents the need for CAP_READ_SEARCH when using systemd's CapabilityBoundingSet, or dac_read_search when using SELinux. Implements part of ticket 17562. Patch from Jamie Nguyen.
Introduce a new DataDirectoryGroupReadable option. If it is set to 1, the DataDirectory will be made readable by the default GID. Implements part of ticket 17562. Patch from Jamie Nguyen.
Minor bugfixes (accounting):
The max bandwidth when using 'AccountRule sum' is now correctly logged. Fixes bug 18024; bugfix on 0.2.6.1-alpha. Patch from "unixninja92".
Minor bugfixes (code correctness):
When closing an entry connection, generate a warning if we should have sent an end cell for it but we haven't. Fixes bug 17876; bugfix on 0.2.3.2-alpha.
Assert that allocated memory held by the reputation code is freed according to its internal counters. Fixes bug 17753; bugfix on tor-0.1.1.1-alpha.
Assert when the TLS contexts fail to initialize. Fixes bug 17683; bugfix on 0.0.6.
Minor bugfixes (compilation):
Mark all object files that include micro-revision.i as depending on it, so as to make parallel builds more reliable. Fixes bug 17826; bugfix on 0.2.5.1-alpha.
Don't try to use the pthread_condattr_setclock() function unless it actually exists. Fixes compilation on NetBSD-6.x. Fixes bug 17819; bugfix on 0.2.6.3-alpha.
Fix backtrace compilation on FreeBSD. Fixes bug 17827; bugfix on tor-0.2.5.2-alpha.
Fix compilation of sandbox.c with musl-libc. Fixes bug 17347; bugfix on 0.2.5.1-alpha. Patch from 'jamestk'.
Fix search for libevent libraries on OpenBSD (and other systems that install libevent 1 and libevent 2 in parallel). Fixes bug 16651; bugfix on 0.1.0.7-rc. Patch from "rubiate".
Isolate environment variables meant for tests from the rest of the build system. Fixes bug 17818; bugfix on tor-0.2.7.3-rc.
Replace usage of 'INLINE' with 'inline'. Fixes bug 17804; bugfix on tor-0.0.2pre8.
Remove config.log only from make distclean, not from make clean. Fixes bug 17924; bugfix on 0.2.4.1-alpha.
Minor bugfixes (crypto):
Check the return value of HMAC() and assert on failure. Fixes bug 17658; bugfix on 0.2.3.6-alpha. Patch by "teor".
Minor bugfixes (fallback directories):
Mark fallbacks as "too busy" when they return a 503 response, rather than just marking authorities. Fixes bug 17572; bugfix on 0.2.4.7-alpha. Patch by "teor".
Minor bugfixes (IPv6):
Update the limits in max_dl_per_request for IPv6 address length. Fixes bug 17573; bugfix on 0.2.1.5-alpha.
Minor bugfixes (linux seccomp2 sandbox):
Fix a crash when using offline master ed25519 keys with the Linux seccomp2 sandbox enabled. Fixes bug 17675; bugfix on 0.2.7.3-alpha.
Minor bugfixes (logging):
In log messages that include a function name, use __FUNCTION__ instead of __PRETTY_FUNCTION__. In GCC, these are synonymous, but with clang __PRETTY_FUNCTION__ has extra information we don't need. Fixes bug 16563; bugfix on 0.0.2pre8. Fix by Tom van der Woerdt.
Remove needless quotes from a log message about unparseable addresses. Fixes bug 17843; bugfix on 0.2.3.3-alpha.
Minor bugfixes (portability):
Remove an #endif from configure.ac so that we correctly detect the presence of in6_addr.s6_addr32. Fixes bug 17923; bugfix on 0.2.0.13-alpha.
Minor bugfixes (relays):
Check that both the ORPort and DirPort (if present) are reachable before publishing a relay descriptor. Otherwise, relays publish a descriptor with DirPort 0 when the DirPort reachability test takes longer than the ORPort reachability test. Fixes bug 18050; bugfix on 0.1.0.1-rc. Reported by "starlight", patch by "teor".
Minor bugfixes (relays, hidden services):
Refuse connection requests to private OR addresses unless ExtendAllowPrivateAddresses is set. Previously, tor would connect, then refuse to send any cells to a private address. Fixes bugs 17674 and 8976; bugfix on 0.2.3.21-rc. Patch by "teor".
Minor bugfixes (safe logging):
When logging a malformed hostname received through socks4, scrub it if SafeLogging says we should. Fixes bug 17419; bugfix on 0.1.1.16-rc.
Minor bugfixes (statistics code):
Consistently check for overflow in round_*_to_next_multiple_of functions, and add unit tests with additional and maximal values. Fixes part of bug 13192; bugfix on 0.2.2.1-alpha.
Handle edge cases in the laplace functions: avoid division by zero, avoid taking the log of zero, and silence clang type conversion warnings using round and trunc. Add unit tests for edge cases with maximal values. Fixes part of bug 13192; bugfix on 0.2.6.2-alpha.
Minor bugfixes (testing):
The test for log_heartbeat was incorrectly failing in timezones with non-integer offsets. Instead of comparing the end of the time string against a constant, compare it to the output of format_local_iso_time when given the correct input. Fixes bug 18039; bugfix on 0.2.5.4-alpha.
Make unit tests pass on IPv6-only systems, and systems without localhost addresses (like some FreeBSD jails). Fixes bug 17632; bugfix on 0.2.7.3-rc. Patch by "teor".
Fix a memory leak in the ntor test. Fixes bug 17778; bugfix on 0.2.4.8-alpha.
Check the full results of SHA256 and SHA512 digests in the unit tests. Bugfix on 0.2.2.4-alpha. Patch by "teor".
Code simplification and refactoring:
Move logging of redundant policy entries in policies_parse_exit_policy_internal into its own function. Closes ticket 17608; patch from "juce".
Extract the more complicated parts of circuit_mark_for_close() into a new function that we run periodically before circuits are freed. This change removes more than half of the functions currently in the "blob". Closes ticket 17218.
Clean up a little duplicated code in crypto_expand_key_material_TAP(). Closes ticket 17587; patch from "pfrankw".
Decouple the list of streams waiting to be attached to circuits from the overall connection list. This change makes it possible to attach streams quickly while simplifying Tor's callgraph and avoiding O(N) scans of the entire connection list. Closes ticket 17590.
When a direct directory request fails immediately on launch, instead of relaunching that request from inside the code that launches it, instead mark the connection for teardown. This change simplifies Tor's callback and prevents the directory-request launching code from invoking itself recursively. Closes ticket 17589
Remove code for configuring OpenSSL dynamic locks; OpenSSL doesn't use them. Closes ticket 17926.
Documentation:
Add a description of the correct use of the '--keygen' command- line option. Closes ticket 17583; based on text by 's7r'.
Document the minimum HeartbeatPeriod value. Closes ticket 15638.
Explain actual minima for BandwidthRate. Closes ticket 16382.
Fix a minor formatting typo in the manpage. Closes ticket 17791.
Mention torspec URL in the manpage and point the reader to it whenever we mention a document that belongs in torspce. Fixes issue 17392.
Removed features:
Remove client-side support for connecting to Tor relays running versions of Tor before 0.2.3.6-alpha. These relays didn't support the v3 TLS handshake protocol, and are no longer allowed on the Tor network. Implements the client side of ticket 11150. Based on patches by Tom van der Woerdt.
Testing:
Add unit tests to check for common RNG failure modes, such as returning all zeroes, identical values, or incrementing values (OpenSSL's rand_predictable feature). Patch by "teor".
Log more information when the backtrace tests fail. Closes ticket 17892. Patch from "cypherpunks."
Always test both ed25519 backends, so that we can be sure that our batch-open replacement code works. Part of ticket 16794.
Cover dns_resolve_impl() in dns.c with unit tests. Implements a portion of ticket 16831.
More unit tests for compat_libevent.c, procmon.c, tortls.c, util_format.c, directory.c, and options_validate.c. Closes tickets 17075, 17082, 17084, 17003, and 17076 respectively. Patches from Ola Bini.
Unit tests for directory_handle_command_get. Closes ticket 17004. Patch from Reinaldo de Souza Jr.

New in Tor 0.2.7.6 (Dec 10, 2015)

New in Tor 0.2.7.5 (Nov 20, 2015)

New in Tor 0.2.7.4 RC (Oct 21, 2015)

Tor 0.2.7.4-rc is the second release candidate in the 0.2.7 series. It fixes some important memory leaks, and a scary-looking (but mostly harmless in practice) invalid-read bug. It also has a few small bug fixes, notably fixes for compilation and portability on different platforms. If no further significant bounds are found, the next release will the the official stable release.
Major bug fixes (security, correctness):
Fix an error that could cause us to read 4 bytes before the beginning of an openssl string. This bug could be used to cause Tor to crash on systems with unusual malloc implementations, or systems with unusual hardening installed. Fixes bug 17404; bugfix on 0.2.3.6-alpha.
Major bug fixes (correctness):
Fix a use-after-free bug in validate_intro_point_failure(). Fixes bug 17401; bugfix on 0.2.7.3-rc.
Major bug fixes (memory leaks):
Fix a memory leak in ed25519 batch signature checking. Fixes bug 17398; bugfix on 0.2.6.1-alpha.
Fix a memory leak in rend_cache_failure_entry_free(). Fixes bug 17402; bugfix on 0.2.7.3-rc.
Fix a memory leak when reading an expired signing key from disk. Fixes bug 17403; bugfix on 0.2.7.2-rc.
Minor features (geoIP):
Update geoip and geoip6 to the October 9 2015 Maxmind GeoLite2 Country database.
Minor bug fixes (compilation):
Repair compilation with the most recent (unreleased, alpha) vesions of OpenSSL 1.1. Fixes part of ticket 17237.
Fix an integer overflow warning in test_crypto_slow.c. Fixes bug 17251; bugfix on 0.2.7.2-alpha.
Fix compilation of sandbox.c with musl-libc. Fixes bug 17347; bugfix on 0.2.5.1-alpha. Patch from 'jamestk'.
Minor bug fixes (portability):
Use libexecinfo on FreeBSD to enable backtrace support. Fixes part of bug 17151; bugfix on 0.2.5.2-alpha. Patch from Marcin Cieślak.
Minor bug fixes (sandbox):
Add the "hidserv-stats" filename to our sandbox filter for the HiddenServiceStatistics option to work properly. Fixes bug 17354; bugfix on tor-0.2.6.2-alpha. Patch from David Goulet.
Minor bug fixes (testing):
Add unit tests for get_interface_address* failure cases. Fixes bug 17173; bugfix on 0.2.7.3-rc. Patch by fk/teor.
Fix breakage when running 'make check' with BSD make. Fixes bug 17154; bugfix on 0.2.7.3-rc. Patch by Marcin Cieślak.
Make the get_ifaddrs_* unit tests more tolerant of different network configurations. (Don't assume every test box has an IPv4 address, and don't assume every test box has a non-localhost address.) Fixes bug 17255; bugfix on 0.2.7.3-rc. Patch by "teor".
Skip backtrace tests when backtrace support is not compiled in. Fixes part of bug 17151; bugfix on 0.2.7.1-alpha. Patch from Marcin Cieślak.
Documentation:
Fix capitalization of SOCKS in sample torrc. Closes ticket 15609.
Note that HiddenServicePorts can take a unix domain socket. Closes ticket 17364.

New in Tor 0.2.7.3 RC (Sep 27, 2015)

Major features (security, hidden services):
Hidden services, if using the EntryNodes option, are required to use more than one EntryNode, in order to avoid a guard discovery attack. (This would only affect people who had configured hidden services and manually specified the EntryNodes option with a single entry-node. The impact was that it would be easy to remotely identify the guard node used by such a hidden service. See ticket for more information.) Fixes ticket 14917.
Major features (Ed25519 keys, keypinning):
The key-pinning option on directory authorities is now advisory- only by default. In a future version, or when the AuthDirPinKeys option is set, pins are enforced again. Disabling key-pinning seemed like a good idea so that we can survive the fallout of any usability problems associated with Ed25519 keys. Closes ticket 17135.
Major features (Ed25519 performance):
Improve the speed of Ed25519 operations and Curve25519 keypair generation when built targeting 32 bit x86 platforms with SSE2 available. Implements ticket 16535.
Improve the runtime speed of Ed25519 signature verification by using Ed25519-donna's batch verification support. Implements ticket 16533.
Major features (performance testing):
The test-network.sh script now supports performance testing. Requires corresponding chutney performance testing changes. Patch by "teor". Closes ticket 14175.
Major features (relay, Ed25519):
Significant usability improvements for Ed25519 key management. Log messages are better, and the code can recover from far more failure conditions. Thanks to "s7r" for reporting and diagnosing so many of these!
Add a new OfflineMasterKey option to tell Tor never to try loading or generating a secret Ed25519 identity key. You can use this in combination with tor --keygen to manage offline and/or encrypted Ed25519 keys. Implements ticket 16944.
Add a --newpass option to allow changing or removing the passphrase of an encrypted key with tor --keygen. Implements part of ticket 16769.
On receiving a HUP signal, check to see whether the Ed25519 signing key has changed, and reload it if so. Closes ticket 16790.
Major bugfixes (relay, Ed25519):
Avoid crashing on 'tor --keygen'. Fixes bug 16679; bugfix on 0.2.7.2-alpha. Reported by "s7r".
Improve handling of expired signing keys with offline master keys. Fixes bug 16685; bugfix on 0.2.7.2-alpha. Reported by "s7r".
Minor features (client-side privacy):
New KeyAliveSOCKSAuth option to indefinitely extend circuit lifespan when IsolateSOCKSAuth and streams with SOCKS authentication are attached to the circuit. This allows applications like TorBrowser to manage circuit lifetime on their own. Implements feature 15482.
When logging malformed hostnames from SOCKS5 requests, respect SafeLogging configuration. Fixes bug 16891; bugfix on 0.1.1.16-rc.
Minor features (compilation):
Give a warning as early as possible when trying to build with an unsupported OpenSSL version. Closes ticket 16901.
Fail during configure if we're trying to build against an OpenSSL built without ECC support. Fixes bug 17109, bugfix on 0.2.7.1-alpha which started requiring ECC.
Minor features (geoip):
Update geoip and geoip6 to the September 3 2015 Maxmind GeoLite2 Country database.
Minor features (hidden services):
Relays need to have the Fast flag to get the HSDir flag. As this is being written, we'll go from 2745 HSDirs down to 2342, a ~14% drop. This change should make some attacks against the hidden service directory system harder. Fixes ticket 15963.
Turn on hidden service statistics collection by setting the torrc option HiddenServiceStatistics to "1" by default. (This keeps track only of the fraction of traffic used by hidden services, and the total number of hidden services in existence.) Closes ticket 15254.
Client now uses an introduction point failure cache to know when to fetch or keep a descriptor in their cache. Previously, failures were recorded implicitly, but not explicitly remembered. Closes ticket 16389.
Minor features (testing, authorities, documentation):
New TestingDirAuthVote{Exit,Guard,HSDir}IsStrict flags to explicitly manage consensus flags in testing networks. Patch by "robgjansen", modified by "teor". Implements part of ticket 14882.
Minor bugfixes (security, exit policies):
ExitPolicyRejectPrivate now also rejects the relay's published IPv6 address (if any), and any publicly routable IPv4 or IPv6 addresses on any local interfaces. ticket 17027. Patch by "teor". Fixes bug 17027; bugfix on 0.2.0.11-alpha.
Minor bug fixes (torrc exit policies):
In torrc, "accept6 *" and "reject6 *" ExitPolicy lines now only produce IPv6 wildcard addresses. Previously they would produce both IPv4 and IPv6 wildcard addresses. Patch by "teor". Fixes part of bug 16069; bugfix on 0.2.4.7-alpha.
When parsing torrc ExitPolicies, we now warn for a number of cases where the user's intent is likely to differ from Tor's actual behavior. These include: using an IPv4 address with an accept6 or reject6 line; using "private" on an accept6 or reject6 line; and including any ExitPolicy lines after accept *:* or reject *:*. Related to ticket 16069.
When parsing torrc ExitPolicies, we now issue an info-level message when expanding an "accept/reject *" line to include both IPv4 and IPv6 wildcard addresses. Related to ticket 16069.
In each instance above, usage advice is provided to avoid the message. Resolves ticket 16069. Patch by "teor". Fixes part of bug 16069; bugfix on 0.2.4.7-alpha.
Minor bugfixes (authority):
Don't assign "HSDir" to a router if it isn't Valid and Running. Fixes bug 16524; bugfix on 0.2.7.2-alpha.
Downgrade log messages about Ed25519 key issues if they are in old cached router descriptors. Fixes part of bug 16286; bugfix on 0.2.7.2-alpha.
When we find an Ed25519 key issue in a cached descriptor, stop saying the descriptor was just "uploaded". Fixes another part of bug 16286; bugfix on 0.2.7.2-alpha.
Minor bugfixes (control port):
Repair a warning and a spurious result when getting the maximum number of file descriptors from the controller. Fixes bug 16697; bugfix on 0.2.7.2-alpha.
Minor bugfixes (correctness):
When calling channel_free_list(), avoid calling smartlist_remove() while inside a FOREACH loop. This partially reverts commit 17356fe7fd96af where the correct SMARTLIST_DEL_CURRENT was incorrectly removed. Fixes bug 16924; bugfix on 0.2.4.4-alpha.
Minor bugfixes (documentation):
Advise users on how to configure separate IPv4 and IPv6 exit policies in the manpage and sample torrcs. Related to ticket 16069.
Fix the usage message of tor-resolve(1) so that it no longer lists the removed -F option. Fixes bug 16913; bugfix on 0.2.2.28-beta.
Fix an error in the manual page and comments for TestingDirAuthVoteHSDir[IsStrict], which suggested that a HSDir required "ORPort connectivity". While this is true, it is in no way unique to the HSDir flag. Of all the flags, only HSDirs need a DirPort configured in order for the authorities to assign that particular flag. Patch by "teor". Fixed as part of 14882; bugfix on 0.2.6.3-alpha.
Minor bugfixes (Ed25519):
Fix a memory leak when reading router descriptors with expired Ed25519 certificates. Fixes bug 16539; bugfix on 0.2.7.2-alpha.
Minor bugfixes (linux seccomp2 sandbox):
Allow bridge authorities to run correctly under the seccomp2 sandbox. Fixes bug 16964; bugfix on 0.2.5.1-alpha.
Allow routers with ed25519 keys to run correctly under the seccomp2 sandbox. Fixes bug 16965; bugfix on 0.2.7.2-alpha.
Minor bugfixes (open file limit):
Fix set_max_file_descriptors() to set by default the max open file limit to the current limit when setrlimit() fails. Fixes bug 16274; bugfix on tor- 0.2.0.10-alpha. Patch by dgoulet.
Minor bugfixes (portability):
Try harder to normalize the exit status of the Tor process to the standard-provided range. Fixes bug 16975; bugfix on every version of Tor ever.
Check correctly for Windows socket errors in the workqueue backend. Fixes bug 16741; bugfix on 0.2.6.3-alpha.
Fix the behavior of crypto_rand_time_range() when told to consider times before 1970. (These times were possible when running in a simulated network environment where time()'s output starts at zero.) Fixes bug 16980; bugfix on 0.2.7.1-alpha.
Restore correct operation of TLS client-cipher detection on OpenSSL 1.1. Fixes bug 14047; bugfix on 0.2.7.2-alpha.
Minor bugfixes (relay):
Ensure that worker threads actually exit when a fatal error or shutdown is indicated. This fix doesn't currently affect the behavior of Tor, because Tor workers never indicates fatal error or shutdown except in the unit tests. Fixes bug 16868; bugfix on 0.2.6.3-alpha.
Unblock threads before releasing the work queue mutex to ensure predictable scheduling behavior. Fixes bug 16644; bugfix on 0.2.6.3-alpha.
Code simplification and refactoring:
Change the function that's called when we need to retry all downloads so that it only reschedules the downloads to happen immediately, rather than launching them all at once itself. This further simplifies Tor's callgraph.
Move some format-parsing functions out of crypto.c and crypto_curve25519.c into crypto_format.c and/or util_format.c.
Move the client-only parts of init_keys() into a separate function. Closes ticket 16763.
Simplify the microdesc_free() implementation so that it no longer appears (to code analysis tools) to potentially invoke a huge suite of other microdesc functions.
Simply the control graph further by deferring the inner body of directory_all_unreachable() into a callback. Closes ticket 16762.
Treat the loss of an owning controller as equivalent to a SIGTERM signal. This removes a tiny amount of duplicated code, and simplifies our callgraph. Closes ticket 16788.
When generating an event to send to the controller, we no longer put the event over the network immediately. Instead, we queue these events, and use a Libevent callback to deliver them. This change simplifies Tor's callgraph by reducing the number of functions from which all other Tor functions are reachable. Closes ticket 16695.
Wrap Windows-only C files inside '#ifdef _WIN32' so that tools that try to scan or compile every file on Unix won't decide that they are broken.
Remove the unused "nulterminate" argument from buf_pullup().
Documentation:
Recommend a 40 GB example AccountingMax in torrc.sample rather than a 4 GB max. Closes ticket 16742.
Include the TUNING document in our source tarball. It is referred to in the ChangeLog and an error message. Fixes bug 16929; bugfix on 0.2.6.1-alpha.
Removed code:
The internal pure-C tor-fw-helper tool is now removed from the Tor distribution, in favor of the pure-Go clone available from https://gitweb.torproject.org/tor-fw-helper.git/ . The libraries used by the C tor-fw-helper are not, in our opinion, very confidence- inspiring in their secure-programming techniques. Closes ticket 13338.
Remove the code that would try to aggressively flush controller connections while writing to them. This code was introduced in 0.1.2.7-alpha, in order to keep output buffers from exceeding their limits. But there is no longer a maximum output buffer size, and flushing data in this way caused some undesirable recursions in our call graph. Closes ticket 16480.
Testing:
Make "bridges+hs" the default test network. This tests almost all tor functionality during make test-network, while allowing tests to succeed on non-IPv6 systems. Requires chutney commit 396da92 in test-network-bridges-hs. Closes tickets 16945 (tor) and 16946 (chutney). Patches by "teor".
Autodetect CHUTNEY_PATH if the chutney and Tor sources are side- by-side in the same parent directory. Closes ticket 16903. Patch by "teor".
Use environment variables rather than autoconf substitutions to send variables from the build system to the test scripts. This change should be easier to maintain, and cause 'make distcheck' to work better than before. Fixes bug 17148.
Add a new set of callgraph analysis scripts that use clang to produce a list of which Tor functions are reachable from which other Tor functions. We're planning to use these to help simplify our code structure by identifying illogical dependencies.
Add new 'test-full' and 'test-full-online' targets to run all tests, including integration tests with stem and chutney.
Make the test-workqueue test work on Windows by initializing the network before we begin.
New make target (make test-network-all) to run multiple applicable chutney test cases. Patch from Teor; closes 16953.
Unit test dns_resolve(), dns_clip_ttl() and dns_get_expiry_ttl() functions in dns.c. Implements a portion of ticket 16831.
When building Tor with testing coverage enabled, run Chutney tests (if any) using the 'tor-cov' coverage binary.
When running test-network or test-stem, check for the absence of stem/chutney before doing any build operations.

New in Tor 0.2.6.10 (Jul 13, 2015)

New in Tor 0.2.6.9 (Jun 12, 2015)

New in Tor 0.2.6.8 (May 21, 2015)

New in Tor 0.2.7.1 Alpha (May 13, 2015)

Tor 0.2.7.1-alpha is the first alpha release in its series. It includes numerous small features and bug fixes against previous Tor versions, and numerous small infrastructure improvements. The most notable features are several new ways for controllers to interact with the hidden services subsystem.
New system requirements:
Tor no longer includes workarounds to support Libevent versions before 1.3e. Libevent 2.0 or later is recommended. Closes ticket 15248.
Major features (controller):
Add the ADD_ONION and DEL_ONION commands that allow the creation and management of hidden services via the controller. Closes ticket 6411.
New "GETINFO onions/current" and "GETINFO onions/detached" commands to get information about hidden services created via the controller. Part of ticket 6411.
New HSFETCH command to launch a request for a hidden service descriptor. Closes ticket 14847.
New HSPOST command to upload a hidden service descriptor. Closes ticket 3523. Patch by "DonnchaC".
Major bug fixes (hidden services):
Revert commit that made directory authorities assign the HSDir flag to relay without a DirPort; this was bad because such relays can't handle BEGIN_DIR cells. Fixes bug 15850; bugfix on tor-0.2.6.3-alpha.
Minor features (clock-jump tolerance):
Recover better when our clock jumps back many hours, like might happen for Tails or Whonix users who start with a very wrong hardware clock, use Tor to discover a more accurate time, and then fix their clock. Resolves part of ticket 8766.
Minor features (command-line interface):
Make --hash-password imply --hush to prevent unnecessary noise. Closes ticket 15542. Patch from "cypherpunks".
Print a warning whenever we find a relative file path being used as torrc option. Resolves issue 14018.
Minor features (controller):
Add DirAuthority lines for default directory authorities to the output of the "GETINFO config/defaults" command if not already present. Implements ticket 14840.
Controllers can now use "GETINFO hs/client/desc/id/..." to retrieve items from the client's hidden service descriptor cache. Closes ticket 14845.
Implement a new controller command "GETINFO status/fresh-relay- descs" to fetch a descriptor/extrainfo pair that was generated on demand just for the controller's use. Implements ticket 14784.
Minor features (DoS-resistance):
Make it harder for attackers to overload hidden services with introductions, by blocking multiple introduction requests on the same circuit. Resolves ticket 15515.
Minor features (geoip):
Update geoip to the April 8 2015 Maxmind GeoLite2 Country database.
Update geoip6 to the April 8 2015 Maxmind GeoLite2 Country database.
Minor features (HS popularity countermeasure):
To avoid leaking HS popularity, don't cycle the introduction point when we've handled a fixed number of INTRODUCE2 cells but instead cycle it when a random number of introductions is reached, thus making it more difficult for an attacker to find out the amount of clients that have used the introduction point for a specific HS. Closes ticket 15745.
Minor features (logging):
Include the Tor version in all LD_BUG log messages, since people tend to cut and paste those into the bugtracker. Implements ticket 15026.
Minor features (pluggable transports):
When launching managed pluggable transports on Linux systems, attempt to have the kernel deliver a SIGTERM on tor exit if the pluggable transport process is still running. Resolves ticket 15471.
When launching managed pluggable transports, setup a valid open stdin in the child process that can be used to detect if tor has terminated. The "TOR_PT_EXIT_ON_STDIN_CLOSE" environment variable can be used by implementations to detect this new behavior. Resolves ticket 15435.
Minor features (testing):
Add a test to verify that the compiler does not eliminate our memwipe() implementation. Closes ticket 15377.
Add make rule `check-changes` to verify the format of changes files. Closes ticket 15180.
Add unit tests for control_event_is_interesting(). Add a compile- time check that the number of events doesn't exceed the capacity of control_event_t.event_mask. Closes ticket 15431, checks for bugs similar to 13085. Patch by "teor".
Command-line argument tests moved to Stem. Resolves ticket 14806.
Integrate the ntor, backtrace, and zero-length keys tests into the automake test suite. Closes ticket 15344.
Remove assertions during builds to determine Tor's test coverage. We don't want to trigger these even in assertions, so including them artificially makes our branch coverage look worse than it is. This patch provides the new test-stem-full and coverage-html-full configure options. Implements ticket 15400.
Minor bug fixes (build):
Improve out-of-tree builds by making non-standard rules work and clean up additional files and directories. Fixes bug 15053; bugfix on 0.2.7.0-alpha.
Minor bug fixes (command-line interface):
When "--quiet" is provided along with "--validate-config", do not write anything to stdout on success. Fixes bug 14994; bugfix on 0.2.3.3-alpha.
When complaining about bad arguments to "--dump-config", use stderr, not stdout.
Minor bug fixes (configuration, unit tests):
Only add the default fallback directories when the DirAuthorities, AlternateDirAuthority, and FallbackDir directory config options are set to their defaults. The default fallback directory list is currently empty, this fix will only change tor's behavior when it has default fallback directories. Includes unit tests for consider_adding_dir_servers(). Fixes bug 15642; bugfix on 90f6071d8dc0 in 0.2.4.7-alpha. Patch by "teor".
Minor bug fixes (correctness):
For correctness, avoid modifying a constant string in handle_control_postdescriptor. Fixes bug 15546; bugfix on 0.1.1.16-rc.
Remove side-effects from tor_assert() calls. This was harmless, because we never disable assertions, but it is bad style and unnecessary. Fixes bug 15211; bugfix on 0.2.5.5, 0.2.2.36, and 0.2.0.10.
Minor bug fixes (hidden service):
Fix an out-of-bounds read when parsing invalid INTRODUCE2 cells on a client authorized hidden service. Fixes bug 15823; bugfix on 0.2.1.6-alpha.
Remove an extraneous newline character from the end of hidden service descriptors. Fixes bug 15296; bugfix on 0.2.0.10-alpha.
Minor bug fixes (interface):
Print usage information for --dump-config when it is used without an argument. Also, fix the error message to use different wording and add newline at the end. Fixes bug 15541; bugfix on 0.2.5.1-alpha.
Minor bug fixes (logs):
When building Tor under Clang, do not include an extra set of parentheses in log messages that include function names. Fixes bug 15269; bugfix on every released version of Tor when compiled with recent enough Clang.
Minor bug fixes (network):
When attempting to use fallback technique for network interface lookup, disregard loopback and multicast addresses since they are unsuitable for public communications.
Minor bug fixes (statistics):
Disregard the ConnDirectionStatistics torrc options when Tor is not a relay since in that mode of operation no sensible data is being collected and because Tor might run into measurement hiccups when running as a client for some time, then becoming a relay. Fixes bug 15604; bugfix on 0.2.2.35.
Minor bug fixes (test networks):
When self-testing reachability, use ExtendAllowPrivateAddresses to determine if local/private addresses imply reachability. The previous fix used TestingTorNetwork, which implies ExtendAllowPrivateAddresses, but this excluded rare configurations where ExtendAllowPrivateAddresses is set but TestingTorNetwork is not. Fixes bug 15771; bugfix on 0.2.6.1-alpha. Patch by "teor", issue discovered by CJ Ess.
Minor bug fixes (testing):
Check for matching value in server response in ntor_ref.py. Fixes bug 15591; bugfix on 0.2.4.8-alpha. Reported and fixed by "joelanders".
Set the severity correctly when testing get_interface_addresses_ifaddrs() and get_interface_addresses_win32(), so that the tests fail gracefully instead of triggering an assertion. Fixes bug 15759; bugfix on 0.2.6.3-alpha. Reported by Nicolas Derive.
Code simplification and refactoring:
Move the hacky fallback code out of get_interface_address6() into separate function and get it covered with unit-tests. Resolves ticket 14710.
Refactor hidden service client-side cache lookup to intelligently report its various failure cases, and disentangle failure cases involving a lack of introduction points. Closes ticket 14391.
Use our own Base64 encoder instead of OpenSSL's, to allow more control over the output. Part of ticket 15652.
Documentation:
Improve the descriptions of statistics-related torrc options in the manpage to describe rationale and possible uses cases. Fixes issue 15550.
Improve the layout and formatting of ./configure --help messages. Closes ticket 15024. Patch from "cypherpunks".
Standardize on the term "server descriptor" in the manual page. Previously, we had used "router descriptor", "server descriptor", and "relay descriptor" interchangeably. Part of ticket 14987.
Removed code:
Remove `USE_OPENSSL_BASE64` and the corresponding fallback code and always use the internal Base64 decoder. The internal decoder has been part of tor since tor-0.2.0.10-alpha, and no one should be using the OpenSSL one. Part of ticket 15652.
Remove the 'tor_strclear()' function; use memwipe() instead. Closes ticket 14922.
Removed features:
Remove the (seldom-used) DynamicDHGroups feature. For anti- fingerprinting we now recommend pluggable transports; for forward- secrecy in TLS, we now use the P-256 group. Closes ticket 13736.
Remove the undocumented "--digests" command-line option. It complicated our build process, caused subtle build issues on multiple platforms, and is now redundant since we started including git version identifiers. Closes ticket 14742.
Tor no longer contains checks for ancient directory cache versions that didn't know about microdescriptors.
Tor no longer contains workarounds for stat files generated by super-old versions of Tor that didn't choose guards sensibly.

New in Tor 0.2.6.7 (Apr 7, 2015)

New in Tor 0.2.6.6 (Mar 25, 2015)

New in Tor 0.2.6.5 RC (Mar 19, 2015)

New in Tor 0.2.5.11 (Mar 18, 2015)

Tor 0.2.5.11 is the second stable release in the 0.2.5 series.
It backports several bug fixes from the 0.2.6 branch, including a couple of medium-level security fixes for relays and exit nodes. It also updates the list of directory authorities.
Directory authority changes:
Remove turtles as a directory authority.
Add longclaw as a new (v3) directory authority. This implements ticket 13296. This keeps the directory authority count at 9.
The directory authority Faravahar has a new IP address. This closes ticket 14487.
Major bug fixes (crash, OSX, security):
Fix a remote denial-of-service opportunity caused by a bug in OSX's _strlcat_chk() function. Fixes bug 15205; bug first appeared in OSX 10.9.
Major bug fixes (relay, stability, possible security):
Fix a bug that could lead to a relay crashing with an assertion failure if a buffer of exactly the wrong layout was passed to buf_pullup() at exactly the wrong time. Fixes bug 15083; bugfix on 0.2.0.10-alpha. Patch from 'cypherpunks'.
Do not assert if the 'data' pointer on a buffer is advanced to the very end of the buffer; log a BUG message instead. Only assert if it is past that point. Fixes bug 15083; bugfix on 0.2.0.10-alpha.
Major bug fixes (exit node stability):
Fix an assertion failure that could occur under high DNS load. Fixes bug 14129; bugfix on Tor 0.0.7rc1. Found by "jowr"; diagnosed and fixed by "cypherpunks".
Major bug fixes (Linux seccomp2 sandbox):
Upon receiving sighup with the seccomp2 sandbox enabled, do not crash during attempts to call wait4. Fixes bug 15088; bugfix on 0.2.5.1-alpha. Patch from "sanic".
Minor features (controller):
New "GETINFO bw-event-cache" to get information about recent bandwidth events. Closes ticket 14128. Useful for controllers to get recent bandwidth history after the fix for ticket 13988.
Minor features (geoip):
Update geoip to the March 3 2015 Maxmind GeoLite2 Country database.
Update geoip6 to the March 3 2015 Maxmind GeoLite2 Country database.
Minor bug fixes (client, automapping):
Avoid crashing on torrc lines for VirtualAddrNetworkIPv[4|6] when no value follows the option. Fixes bug 14142; bugfix on 0.2.4.7-alpha. Patch by "teor".
Fix a memory leak when using AutomapHostsOnResolve. Fixes bug 14195; bugfix on 0.1.0.1-rc.
Minor bug fixes (compilation):
Build without warnings with the stock OpenSSL srtp.h header, which has a duplicate declaration of SSL_get_selected_srtp_profile(). Fixes bug 14220; this is OpenSSL's bug, not ours.
Minor bug fixes (directory authority):
Allow directory authorities to fetch more data from one another if they find themselves missing lots of votes. Previously, they had been bumping against the 10 MB queued data limit. Fixes bug 14261; bugfix on 0.1.2.5-alpha.
Enlarge the buffer to read bwauth generated files to avoid an issue when parsing the file in dirserv_read_measured_bandwidths(). Fixes bug 14125; bugfix on 0.2.2.1-alpha.
Minor bug fixes (statistics):
Increase period over which bandwidth observations are aggregated from 15 minutes to 4 hours. Fixes bug 13988; bugfix on 0.0.8pre1.
Minor bug fixes (preventative security, C safety):
When reading a hexadecimal, base-32, or base-64 encoded value from a string, always overwrite the whole output buffer. This prevents some bugs where we would look at (but fortunately, not reveal) uninitialized memory on the stack. Fixes bug 14013; bugfix on all versions of Tor.

New in Tor 0.2.6.4 RC (Mar 10, 2015)

Tor 0.2.6.4 RC fixes an issue in the directory code that an attacker might be able to use in order to crash certain Tor directories. It also resolves some minor issues left over from, or introduced in, Tor 0.2.6.3-alpha or earlier.
Major bug fixes (crash, OSX, security):
Fix a remote denial-of-service opportunity caused by a bug in OSX's _strlcat_chk() function. Fixes bug 15205; bug first appeared in OSX 10.9.
Major bug fixes (relay, stability, possible security):
Fix a bug that could lead to a relay crashing with an assertion failure if a buffer of exactly the wrong layout is passed to buf_pullup() at exactly the wrong time. Fixes bug 15083; bugfix on 0.2.0.10-alpha. Patch from "cypherpunks".
Do not assert if the 'data' pointer on a buffer is advanced to the very end of the buffer; log a BUG message instead. Only assert if it is past that point. Fixes bug 15083; bugfix on 0.2.0.10-alpha.
Major bug fixes (FreeBSD IPFW transparent proxy):
Fix address detection with FreeBSD transparent proxies, when "TransProxyType ipfw" is in use. Fixes bug 15064; bugfix on 0.2.5.4-alpha.
Major bug fixes (Linux seccomp2 sandbox):
Pass IPPROTO_TCP rather than 0 to socket(), so that the Linux seccomp2 sandbox doesn't fail. Fixes bug 14989; bugfix on 0.2.6.3-alpha.
Allow AF_UNIX hidden services to be used with the seccomp2 sandbox. Fixes bug 15003; bugfix on 0.2.6.3-alpha.
Upon receiving sighup with the seccomp2 sandbox enabled, do not crash during attempts to call wait4. Fixes bug 15088; bugfix on 0.2.5.1-alpha. Patch from "sanic".
Minor features (controller):
Messages about problems in the bootstrap process now include information about the server we were trying to connect to when we noticed the problem. Closes ticket 15006.
Minor features (geoip):
Update geoip to the March 3 2015 Maxmind GeoLite2 Country database.
Update geoip6 to the March 3 2015 Maxmind GeoLite2 Country database.
Minor features (logs):
Quiet some log messages in the heartbeat and at startup. Closes ticket 14950.
Minor bug fixes (certificate handling):
If an authority operator accidentally makes a signing certificate with a future publication time, do not discard its real signing certificates. Fixes bug 11457; bugfix on 0.2.0.3-alpha.
Remove any old authority certificates that have been superseded for at least two days. Previously, we would keep superseded certificates until they expired, if they were published close in time to the certificate that superseded them. Fixes bug 11454; bugfix on 0.2.1.8-alpha.
Minor bug fixes (compilation):
Fix a compilation warning on s390. Fixes bug 14988; bugfix on 0.2.5.2-alpha.
Fix a compilation warning on FreeBSD. Fixes bug 15151; bugfix on 0.2.6.2-alpha.
Minor bug fixes (testing):
Fix endianness issues in unit test for resolve_my_address() to have it pass on big endian systems. Fixes bug 14980; bugfix on Tor 0.2.6.3-alpha.
Avoid a side-effect in a tor_assert() in the unit tests. Fixes bug 15188; bugfix on 0.1.2.3-alpha. Patch from Tom van der Woerdt.
When running the new 'make test-stem' target, use the configured python binary. Fixes bug 15037; bugfix on 0.2.6.3-alpha. Patch from "cypherpunks".
When running the zero-length-keys tests, do not use the default torrc file. Fixes bug 15033; bugfix on 0.2.6.3-alpha. Reported by "reezer".
Directory authority IP change:
The directory authority Faravahar has a new IP address. This closes ticket 14487.
Removed code:
Remove some lingering dead code that once supported mempools. Mempools were disabled by default in 0.2.5, and removed entirely in 0.2.6.3-alpha. Closes more of ticket 14848; patch by "cypherpunks".

New in Tor 0.2.6.3 Alpha (Feb 23, 2015)

Tor 0.2.6.3-alpha is the third (and hopefully final) alpha release in the 0.2.6.x series. It introduces support for more kinds of sockets, makes it harder to accidentally run an exit, improves our multithreading backend, incorporates several fixes for the AutomapHostsOnResolve option, and fixes numerous other bugs besides.
If no major regressions or security holes are found in this version, the next version will be a release candidate.
Deprecated versions:
Tor relays older than 0.2.4.18-rc are no longer allowed to advertise themselves on the network. Closes ticket 13555.
Major features (security, unix domain sockets):
Allow SocksPort to be an AF_UNIX Unix Domain Socket. Now high risk applications can reach Tor without having to create AF_INET or AF_INET6 sockets, meaning they can completely disable their ability to make non-Tor network connections. To create a socket of this type, use "SocksPort unix:/path/to/socket". Implements ticket 12585.
Support mapping hidden service virtual ports to AF_UNIX sockets. The syntax is "HiddenServicePort 80 unix:/path/to/socket". Implements ticket 11485.
Major features (changed defaults):
Prevent relay operators from unintentionally running exits: When a relay is configured as an exit node, we now warn the user unless the "ExitRelay" option is set to 1. We warn even more loudly if the relay is configured with the default exit policy, since this can indicate accidental misconfiguration. Setting "ExitRelay 0" stops Tor from running as an exit relay. Closes ticket 10067.
Major features (directory system):
When downloading server- or microdescriptors from a directory server, we no longer launch multiple simultaneous requests to the same server. This reduces load on the directory servers, especially when directory guards are in use. Closes ticket 9969.
When downloading server- or microdescriptors over a tunneled connection, do not limit the length of our requests to what the Squid proxy is willing to handle. Part of ticket 9969.
Authorities can now vote on the correct digests and latest versions for different software packages. This allows packages that include Tor to use the Tor authority system as a way to get notified of updates and their correct digests. Implements proposal 227. Closes ticket 10395.
Major features (performance):
Make the CPU worker implementation more efficient by avoiding the kernel and lengthening pipelines. The original implementation used sockets to transfer data from the main thread to the workers, and didn't allow any thread to be assigned more than a single piece of work at once. The new implementation avoids communications overhead by making requests in shared memory, avoiding kernel IO where possible, and keeping more requests in flight at once. Implements ticket 9682.
Major features (relay):
Raise the minimum acceptable configured bandwidth rate for bridges to 50 KiB/sec and for relays to 75 KiB/sec. (The old values were 20 KiB/sec.) Closes ticket 13822.
Major bug fixes (exit node stability):
Fix an assertion failure that could occur under high DNS load. Fixes bug 14129; bugfix on Tor 0.0.7rc1. Found by "jowr"; diagnosed and fixed by "cypherpunks".
Major bug fixes (mixed relay-client operation):
When running as a relay and client at the same time (not recommended), if we decide not to use a new guard because we want to retry older guards, only close the locally-originating circuits passing through that guard. Previously we would close all the circuits through that guard. Fixes bug 9819; bugfix on 0.2.1.1-alpha. Reported by "skruffy".
Minor features (build):
New --disable-system-torrc compile-time option to prevent Tor from looking for the system-wide torrc or torrc-defaults files. Resolves ticket 13037.
Minor features (controller):
Include SOCKS_USERNAME and SOCKS_PASSWORD values in controller events so controllers can observe circuit isolation inputs. Closes ticket 8405.
ControlPort now supports the unix:/path/to/socket syntax as an alternative to the ControlSocket option, for consistency with SocksPort and HiddenServicePort. Closes ticket 14451.
New "GETINFO bw-event-cache" to get information about recent bandwidth events. Closes ticket 14128. Useful for controllers to get recent bandwidth history after the fix for ticket 13988.
Minor features (Denial of service resistance):
Count the total number of bytes used storing hidden service descriptors against the value of MaxMemInQueues. If we're low on memory, and more than 20% of our memory is used holding hidden service descriptors, free them until no more than 10% of our memory holds hidden service descriptors. Free the least recently fetched descriptors first. Resolves ticket 13806.
When we have recently been under memory pressure (over 3/4 of MaxMemInQueues is allocated), then allocate smaller zlib objects for small requests. Closes ticket 11791.
Minor features (geoip):
Update geoip and geoip6 files to the January 7 2015 Maxmind GeoLite2 Country database.
Minor features (guard nodes):
Reduce the time delay before saving guard status to disk from 10 minutes to 30 seconds (or from one hour to 10 minutes if AvoidDiskWrites is set). Closes ticket 12485.
Minor features (hidden service):
Make Sybil attacks against hidden services harder by changing the minimum time required to get the HSDir flag from 25 hours up to 96 hours. Addresses ticket 14149.
New option "HiddenServiceAllowUnknownPorts" to allow hidden services to disable the anti-scanning feature introduced in 0.2.6.2-alpha. With this option not set, a connection to an unlisted port closes the circuit. With this option set, only a RELAY_DONE cell is sent. Closes ticket 14084.
Minor features (interface):
Implement "-f -" command-line option to read torrc configuration from standard input, if you don't want to store the torrc file in the file system. Implements feature 13865.
Minor features (logging):
Add a count of unique clients to the bridge heartbeat message. Resolves ticket 6852.
Suppress "router info incompatible with extra info" message when reading extrainfo documents from cache. (This message got loud around when we closed bug 9812 in 0.2.6.2-alpha.) Closes ticket 13762.
Elevate hidden service authorized-client message from DEBUG to INFO. Closes ticket 14015.
Minor features (stability):
Add assertions in our hash-table iteration code to check for corrupted values that could cause infinite loops. Closes ticket 11737.
Minor features (systemd):
Various improvements and modernizations in systemd hardening support. Closes ticket 13805. Patch from Craig Andrews.
Minor features (testing networks):
Drop the minimum RendPostPeriod on a testing network to 5 seconds, and the default on a testing network to 2 minutes. Drop the MIN_REND_INITIAL_POST_DELAY on a testing network to 5 seconds, but keep the default on a testing network at 30 seconds. This reduces HS bootstrap time to around 25 seconds. Also, change the default time in test-network.sh to match. Closes ticket 13401. Patch by "teor".
Create TestingDirAuthVoteHSDir to correspond to TestingDirAuthVoteExit/Guard. Ensures that authorities vote the HSDir flag for the listed relays regardless of uptime or ORPort connectivity. Respects the value of VoteOnHidServDirectoriesV2. Partial implementation for ticket 14067. Patch by "teor".
Minor features (tor2web mode):
Introduce the config option Tor2webRendezvousPoints, which allows clients in Tor2webMode to select a specific Rendezvous Point to be used in HS circuits. This might allow better performance for Tor2Web nodes. Implements ticket 12844.
Minor bug fixes (client DNS):
Report the correct cached DNS expiration times on SOCKS port or in DNS replies. Previously, we would report everything as "never expires." Fixes bug 14193; bugfix on 0.2.3.17-beta.
Avoid a small memory leak when we find a cached answer for a reverse DNS lookup in a client-side DNS cache. (Remember, client- side DNS caching is off by default, and is not recommended.) Fixes bug 14259; bugfix on 0.2.0.1-alpha.
Minor bug fixes (client, automapping):
Avoid crashing on torrc lines for VirtualAddrNetworkIPv[4|6] when no value follows the option. Fixes bug 14142; bugfix on 0.2.4.7-alpha. Patch by "teor".
Fix a memory leak when using AutomapHostsOnResolve. Fixes bug 14195; bugfix on 0.1.0.1-rc.
Prevent changes to other options from removing the wildcard value "." from "AutomapHostsSuffixes". Fixes bug 12509; bugfix on 0.2.0.1-alpha.
Allow MapAddress and AutomapHostsOnResolve to work together when an address is mapped into another address type (like .onion) that must be automapped at resolve time. Fixes bug 7555; bugfix on 0.2.0.1-alpha.
Minor bug fixes (client, bridges):
When we are using bridges and we had a network connectivity problem, only retry connecting to our currently configured bridges, not all bridges we know about and remember using. Fixes bug 14216; bugfix on 0.2.2.17-alpha.
Minor bug fixes (client, IPv6):
Reject socks requests to literal IPv6 addresses when IPv6Traffic flag is not set; and not because the NoIPv4Traffic flag was set. Previously we'd looked at the NoIPv4Traffic flag for both types of literal addresses. Fixes bug 14280; bugfix on 0.2.4.7-alpha.
Minor bug fixes (compilation):
The address of an array in the middle of a structure will always be non-NULL. clang recognises this and complains. Disable the tautologous and redundant check to silence this warning. Fixes bug 14001; bugfix on 0.2.1.2-alpha.
Avoid warnings when building with systemd 209 or later. Fixes bug 14072; bugfix on 0.2.6.2-alpha. Patch from "h.venev".
Compile correctly with (unreleased) OpenSSL 1.1.0 headers. Addresses ticket 14188.
Build without warnings with the stock OpenSSL srtp.h header, which has a duplicate declaration of SSL_get_selected_srtp_profile(). Fixes bug 14220; this is OpenSSL's bug, not ours.
Do not compile any code related to Tor2Web mode when Tor2Web mode is not enabled at compile time. Previously, this code was included in a disabled state. See discussion on ticket 12844.
Remove the --disable-threads configure option again. It was accidentally partially reintroduced in 29ac883606d6d. Fixes bug 14819; bugfix on 0.2.6.2-alpha.
Minor bug fixes (controller):
Report "down" in response to the "GETINFO entry-guards" command when relays are down with an unreachable_since value. Previously, we would report "up". Fixes bug 14184; bugfix on 0.1.2.2-alpha.
Avoid crashing on a malformed EXTENDCIRCUIT command. Fixes bug 14116; bugfix on 0.2.2.9-alpha.
Add a code for the END_CIRC_REASON_IP_NOW_REDUNDANT circuit close reason. Fixes bug 14207; bugfix on 0.2.6.2-alpha.
Minor bug fixes (directory authority):
Allow directory authorities to fetch more data from one another if they find themselves missing lots of votes. Previously, they had been bumping against the 10 MB queued data limit. Fixes bug 14261; bugfix on 0.1.2.5-alpha.
Do not attempt to download extrainfo documents which we will be unable to validate with a matching server descriptor. Fixes bug 13762; bugfix on 0.2.0.1-alpha.
Fix a bug that was truncating AUTHDIR_NEWDESC events sent to the control port. Fixes bug 14953; bugfix on 0.2.0.1-alpha.
Enlarge the buffer to read bwauth generated files to avoid an issue when parsing the file in dirserv_read_measured_bandwidths(). Fixes bug 14125; bugfix on 0.2.2.1-alpha.
Minor bug fixes (file handling):
Stop failing when key files are zero-length. Instead, generate new keys, and overwrite the empty key files. Fixes bug 13111; bugfix on all versions of Tor. Patch by "teor".
Stop generating a fresh .old RSA onion key file when the .old file is missing. Fixes part of 13111; bugfix on 0.0.6rc1.
Avoid overwriting .old key files with empty key files.
Skip loading zero-length extrainfo store, router store, stats, state, and key files.
Avoid crashing when trying to reload a torrc specified as a relative path with RunAsDaemon turned on. Fixes bug 13397; bugfix on 0.2.3.11-alpha.
Minor bug fixes (hidden services):
Close the introduction circuit when we have no more usable intro points, instead of waiting for it to time out. This also ensures that no follow-up HS descriptor fetch is triggered when the circuit eventually times out. Fixes bug 14224; bugfix on 0.0.6.
When fetching a hidden service descriptor for a down service that was recently up, do not keep refetching until we try the same replica twice in a row. Fixes bug 14219; bugfix on 0.2.0.10-alpha.
Successfully launch Tor with a nonexistent hidden service directory. Our fix for bug 13942 didn't catch this case. Fixes bug 14106; bugfix on 0.2.6.2-alpha.
Minor bug fixes (logging):
Avoid crashing when there are more log domains than entries in domain_list. Bugfix on 0.2.3.1-alpha.
Add a string representation for LD_SCHED. Fixes bug 14740; bugfix on 0.2.6.1-alpha.
Don't log messages to stdout twice when starting up. Fixes bug 13993; bugfix on 0.2.6.1-alpha.
Minor bug fixes (parsing):
Stop accepting milliseconds (or other junk) at the end of descriptor publication times. Fixes bug 9286; bugfix on 0.0.2pre25.
Support two-number and three-number version numbers correctly, in case we change the Tor versioning system in the future. Fixes bug 13661; bugfix on 0.0.8pre1.
Minor bug fixes (path counting):
When deciding whether the consensus lists any exit nodes, count the number listed in the consensus, not the number we have descriptors for. Fixes part of bug 14918; bugfix on 0.2.6.2-alpha.
When deciding whether we have any exit nodes, only examine ExitNodes when the ExitNodes option is actually set. Fixes part of bug 14918; bugfix on 0.2.6.2-alpha.
Get rid of redundant and possibly scary warnings that we are missing directory information while we bootstrap. Fixes part of bug 14918; bugfix on 0.2.6.2-alpha.
Minor bug fixes (portability):
Fix the ioctl()-based network interface lookup code so that it will work on systems that have variable-length struct ifreq, for example Mac OS X.
Fix scheduler compilation on targets where char is unsigned. Fixes bug 14764; bugfix on 0.2.6.2-alpha. Reported by Christian Kujau.
Minor bug fixes (sandbox):
Allow glibc fatal errors to be sent to stderr before Tor exits. Previously, glibc would try to write them to /dev/tty, and the sandbox would trap the call and make Tor exit prematurely. Fixes bug 14759; bugfix on 0.2.5.1-alpha.
Minor bug fixes (shutdown):
When shutting down, always call event_del() on lingering read or write events before freeing them. Otherwise, we risk double-frees or read-after-frees in event_base_free(). Fixes bug 12985; bugfix on 0.1.0.2-rc.
Minor bug fixes (small memory leaks):
Avoid leaking memory when using IPv6 virtual address mappings. Fixes bug 14123; bugfix on 0.2.4.7-alpha. Patch by Tom van der Woerdt.
Minor bug fixes (statistics):
Increase period over which bandwidth observations are aggregated from 15 minutes to 4 hours. Fixes bug 13988; bugfix on 0.0.8pre1.
Minor bug fixes (systemd support):
Fix detection and operation of systemd watchdog. Fixes part of bug 14141; bugfix on 0.2.6.2-alpha. Patch from Tomasz Torcz.
Run correctly under systemd with the RunAsDaemon option set. Fixes part of bug 14141; bugfix on 0.2.5.7-rc. Patch from Tomasz Torcz.
Inform the systemd supervisor about more changes in the Tor process status. Implements part of ticket 14141. Patch from Tomasz Torcz.
Cause the "--disable-systemd" option to actually disable systemd support. Fixes bug 14350; bugfix on 0.2.6.2-alpha. Patch from "blueness".
Minor bug fixes (TLS):
Check more thoroughly throughout the TLS code for possible unlogged TLS errors. Possible diagnostic or fix for bug 13319.
Minor bug fixes (transparent proxy):
Use getsockname, not getsockopt, to retrieve the address for a TPROXY-redirected connection. Fixes bug 13796; bugfix on 0.2.5.2-alpha.
Code simplification and refactoring:
Move fields related to isolating and configuring client ports into a shared structure. Previously, they were duplicated across port_cfg_t, listener_connection_t, and edge_connection_t. Failure to copy them correctly had been the cause of at least one bug in the past. Closes ticket 8546.
Refactor the get_interface_addresses_raw() doom-function into multiple smaller and simpler subfunctions. Cover the resulting subfunctions with unit-tests. Fixes a significant portion of issue 12376.
Remove workaround in dirserv_thinks_router_is_hs_dir() that was only for version

New in Tor 0.2.6.2 Alpha (Jan 3, 2015)

Tor 0.2.6.2-alpha is the second alpha release in the 0.2.6.x series. It introduces a major new backend for deciding when to send cells on channels, which should lead down the road to big performance increases. It contains security and statistics features for better work on hidden services, and numerous bug fixes.
This release contains many new unit tests, along with major performance improvements for running testing networks using Chutney. Thanks to a series of patches contributed by "teor", testing networks should now bootstrap in seconds, rather than minutes.
Major features (relay, infrastructure):
Complete revision of the code that relays use to decide which cell to send next. Formerly, we selected the best circuit to write on each channel, but we didn't select among channels in any sophisticated way. Now, we choose the best circuits globally from among those whose channels are ready to deliver traffic.
This patch implements a new inter-cmux comparison API, a global high/low watermark mechanism and a global scheduler loop for transmission prioritization across all channels as well as among circuits on one channel. This schedule is currently tuned to (tolerantly) avoid making changes in network performance, but it should form the basis for major circuit performance increases in the future. Code by Andrea; tuning by Rob Jansen; implements ticket 9262.
Major features (hidden services):
Make HS port scanning more difficult by immediately closing the circuit when a user attempts to connect to a nonexistent port. Closes ticket 13667.
Add a HiddenServiceStatistics option that allows Tor relays to gather and publish statistics about the overall size and volume of hidden service usage. Specifically, when this option is turned on, an HSDir will publish an approximate number of hidden services that have published descriptors to it the past 24 hours. Also, if a relay has acted as a hidden service rendezvous point, it will publish the approximate amount of rendezvous cells it has relayed the past 24 hours. The statistics themselves are obfuscated so that the exact values cannot be derived. For more details see proposal 238, "Better hidden service stats from Tor relays". This feature is currently disabled by default. Implements feature 13192.
Major bug fixes (client, automap):
Repair automapping with IPv6 addresses. This automapping should have worked previously, but one piece of debugging code that we inserted to detect a regression actually caused the regression to manifest itself again. Fixes bug 13811 and bug 12831; bugfix on 0.2.4.7-alpha. Diagnosed and fixed by Francisco Blas Izquierdo Riera.
Major bug fixes (hidden services):
When closing an introduction circuit that was opened in parallel with others, don't mark the introduction point as unreachable. Previously, the first successful connection to an introduction point would make the other introduction points get marked as having timed out. Fixes bug 13698; bugfix on 0.0.6rc2.
Directory authority changes:
Remove turtles as a directory authority.
Add longclaw as a new (v3) directory authority. This implements ticket 13296. This keeps the directory authority count at 9.
Major removed features:
Tor clients no longer support connecting to hidden services running on Tor 0.2.2.x and earlier; the Support022HiddenServices option has been removed. (There shouldn't be any hidden services running these versions on the network.) Closes ticket 7803.
Minor features (client):
Validate hostnames in SOCKS5 requests more strictly. If SafeSocks is enabled, reject requests with IP addresses as hostnames. Resolves ticket 13315.
Minor features (controller):
Add a "SIGNAL HEARTBEAT" controller command that tells Tor to write an unscheduled heartbeat message to the log. Implements feature 9503.
Minor features (geoip):
Update geoip and geoip6 to the November 15 2014 Maxmind GeoLite2 Country database.
Minor features (hidden services):
When re-enabling the network, don't try to build introduction circuits until we have successfully built a circuit. This makes hidden services come up faster when the network is re-enabled. Patch from "akwizgran". Closes ticket 13447.
When we fail to a retrieve hidden service descriptor, send the controller an "HS_DESC FAILED" controller event. Implements feature 13212.
New HiddenServiceDirGroupReadable option to cause hidden service directories and hostname files to be created group-readable. Patch from "anon", David Stainton, and "meejah". Closes ticket 11291.
Minor features (transparent proxy):
Update the transparent proxy option checks to allow for both ipfw and pf on OS X. Closes ticket 14002.
Use the correct option when using IPv6 with transparent proxy support on Linux. Resolves 13808. Patch by Francisco Blas Izquierdo Riera.
Minor bug fixes (preventative security, C safety):
When reading a hexadecimal, base-32, or base-64 encoded value from a string, always overwrite the whole output buffer. This prevents some bugs where we would look at (but fortunately, not reveal) uninitialized memory on the stack. Fixes bug 14013; bugfix on all versions of Tor.
Clear all memory targetted by tor_addr_{to,from}_sockaddr(), not just the part that's used. This makes it harder for data leak bugs to occur in the event of other programming failures. Resolves ticket 14041.
Minor bug fixes (client, microdescriptors):
Use a full 256 bits of the SHA256 digest of a microdescriptor when computing which microdescriptors to download. This keeps us from erroneous download behavior if two microdescriptor digests ever have the same first 160 bits. Fixes part of bug 13399; bugfix on 0.2.3.1-alpha.
Reset a router's status if its microdescriptor digest changes, even if the first 160 bits remain the same. Fixes part of bug 13399; bugfix on 0.2.3.1-alpha.
Minor bug fixes (compilation):
Silence clang warnings under --enable-expensive-hardening, including implicit truncation of 64 bit values to 32 bit, const char assignment to self, tautological compare, and additional parentheses around equality tests. Fixes bug 13577; bugfix on 0.2.5.4-alpha.
Fix a clang warning about checking whether an address in the middle of a structure is NULL. Fixes bug 14001; bugfix on 0.2.1.2-alpha.
Minor bug fixes (hidden services):
Correctly send a controller event when we find that a rendezvous circuit has finished. Fixes bug 13936; bugfix on 0.1.1.5-alpha.
Pre-check directory permissions for new hidden-services to avoid at least one case of "Bug: Acting on config options left us in a broken state. Dying." Fixes bug 13942; bugfix on 0.0.6pre1.
When adding a new hidden service (for example, via SETCONF), Tor no longer congratulates the user for running a relay. Fixes bug 13941; bugfix on 0.2.6.1-alpha.
When fetching hidden service descriptors, we now check not only for whether we got the hidden service we had in mind, but also whether we got the particular descriptors we wanted. This prevents a class of inefficient but annoying DoS attacks by hidden service directories. Fixes bug 13214; bugfix on 0.2.1.6-alpha. Reported by "special".
Minor bug fixes (logging):
Downgrade warnings about RSA signature failures to info log level. Emit a warning when an extra info document is found incompatible with a corresponding router descriptor. Fixes bug 9812; bugfix on 0.0.6rc3.
Make connection_ap_handshake_attach_circuit() log the circuit ID correctly. Fixes bug 13701; bugfix on 0.0.6.
Minor bug fixes (misc):
Stop allowing invalid address patterns like "*/24" that contain both a wildcard address and a bit prefix length. This affects all our address-range parsing code. Fixes bug 7484; bugfix on 0.0.2pre14.
Minor bug fixes (testing networks, fast startup):
Allow Tor to build circuits using a consensus with no exits. If the consensus has no exits (typical of a bootstrapping test network), allow Tor to build circuits once enough descriptors have been downloaded. This assists in bootstrapping a testing Tor network. Fixes bug 13718; bugfix on 0.2.4.10-alpha. Patch by "teor".
When V3AuthVotingInterval is low, give a lower If-Modified-Since header to directory servers. This allows us to obtain consensuses promptly when the consensus interval is very short. This assists in bootstrapping a testing Tor network. Fixes parts of bugs 13718 and 13963; bugfix on 0.2.0.3-alpha. Patch by "teor".
Stop assuming that private addresses are local when checking reachability in a TestingTorNetwork. Instead, when testing, assume all OR connections are remote. (This is necessary due to many test scenarios running all relays on localhost.) This assists in bootstrapping a testing Tor network. Fixes bug 13924; bugfix on 0.1.0.1-rc. Patch by "teor".
Avoid building exit circuits from a consensus with no exits. Now thanks to our fix for 13718, we accept a no-exit network as not wholly lost, but we need to remember not to try to build exit circuits on it. Closes ticket 13814; patch by "teor".
Stop requiring exits to have non-zero bandwithcapacity in a TestingTorNetwork. Instead, when TestingMinExitFlagThreshold is 0, ignore exit bandwidthcapacity. This assists in bootstrapping a testing Tor network. Fixes parts of bugs 13718 and 13839; bugfix on 0.2.0.3-alpha. Patch by "teor".
Add "internal" to some bootstrap statuses when no exits are available. If the consensus does not contain Exits, Tor will only build internal circuits. In this case, relevant statuses will contain the word "internal" as indicated in the Tor control- spec.txt. When bootstrap completes, Tor will be ready to build internal circuits. If a future consensus contains Exits, exit circuits may become available. Fixes part of bug 13718; bugfix on 0.2.4.10-alpha. Patch by "teor".
Decrease minimum consensus interval to 10 seconds when TestingTorNetwork is set, or 5 seconds for the first consensus. Fix assumptions throughout the code that assume larger intervals. Fixes bugs 13718 and 13823; bugfix on 0.2.0.3-alpha. Patch by "teor".
Avoid excluding guards from path building in minimal test networks, when we're in a test network and excluding guards would exclude all relays. This typically occurs in incredibly small tor networks, and those using "TestingAuthVoteGuard *". Fixes part of bug 13718; bugfix on 0.1.1.11-alpha. Patch by "teor".
Code simplification and refactoring:
Stop using can_complete_circuits as a global variable; access it with a function instead.
Avoid using operators directly as macro arguments: this lets us apply coccinelle transformations to our codebase more directly. Closes ticket 13172.
Combine the functions used to parse ClientTransportPlugin and ServerTransportPlugin into a single function. Closes ticket 6456.
Add inline functions and convenience macros for inspecting channel state. Refactor the code to use convenience macros instead of checking channel state directly. Fixes issue 7356.
Document all members of was_router_added_t and rename ROUTER_WAS_NOT_NEW to ROUTER_IS_ALREADY_KNOWN to make it less confusable with ROUTER_WAS_TOO_OLD. Fixes issue 13644.
In connection_exit_begin_conn(), use END_CIRC_REASON_TORPROTOCOL constant instead of hardcoded value. Fixes issue 13840.
Refactor our generic strmap and digestmap types into a single implementation, so that we can add a new digest256map type trivially.
Documentation:
Document the bridge-authority-only 'networkstatus-bridges' file. Closes ticket 13713; patch from "tom".
Fix typo in PredictedPortsRelevanceTime option description in manpage. Resolves issue 13707.
Stop suggesting that users specify relays by nickname: it isn't a good idea. Also, properly cross-reference how to specify relays in all parts of manual documenting options that take a list of relays. Closes ticket 13381.
Clarify the HiddenServiceDir option description in manpage to make it clear that relative paths are taken with respect to the current working directory. Also clarify that this behavior is not guaranteed to remain indefinitely. Fixes issue 13913.
Testing:
New tests for many parts of channel, relay, and circuitmux functionality. Code by Andrea; part of 9262.
New tests for parse_transport_line(). Part of ticket 6456.
In the unit tests, use chgrp() to change the group of the unit test temporary directory to the current user, so that the sticky bit doesn't interfere with tests that check directory groups. Closes 13678.
Add unit tests for resolve_my_addr(). Part of ticket 12376; patch by 'rl1987'.

New in Tor 0.2.6.1 Alpha (Oct 31, 2014)

Tor 0.2.6.1-alpha is the first release in the Tor 0.2.6.x series. It includes numerous code cleanups and new tests, and fixes a large number of annoying bugs. Out-of-memory conditions are handled better than in 0.2.5, pluggable transports have improved proxy support, and clients now use optimistic data for contacting hidden services. Also, we are now more robust to changes in what we consider a parseable directory object, so that tightening restrictions does not have a risk of introducing infinite download loops.
This is the first alpha release in a new series, so expect there to be bugs. Users who would rather test out a more stable branch should stay with 0.2.5.x for now.
New compiler and system requirements:
Tor 0.2.6.x requires that your compiler support more of the C99 language standard than before. The 'configure' script now detects whether your compiler supports C99 mid-block declarations and designated initializers. If it does not, Tor will not compile.
We may revisit this requirement if it turns out that a significant number of people need to build Tor with compilers that don't bother implementing a 15-year-old standard. Closes ticket 13233.
Tor no longer supports systems without threading support. When we began working on Tor, there were several systems that didn't have threads, or where the thread support wasn't able to run the threads of a single process on multiple CPUs. That no longer holds: every system where Tor needs to run well now has threading support. Resolves ticket 12439.
Removed platform support:
We no longer include special code to build on Windows CE; as far as we know, nobody has used Tor on Windows CE in a very long time. Closes ticket 11446.
Major features (bridges):
Expose the outgoing upstream HTTP/SOCKS proxy to pluggable transports if they are configured via the "TOR_PT_PROXY" environment variable. Implements proposal 232. Resolves ticket 8402.
Major features (client performance, hidden services):
Allow clients to use optimistic data when connecting to a hidden service, which should remove a round-trip from hidden service initialization. See proposal 181 for details. Implements ticket 13211.
Major features (directory system):
Upon receiving an unparseable directory object, if its digest matches what we expected, then don't try to download it again. Previously, when we got a descriptor we didn't like, we would keep trying to download it over and over. Closes ticket 11243.
Major features (sample torrc):
Add a new, infrequently-changed "torrc.minimal". This file is similar to torrc.sample, but it will change as infrequently as possible, for the benefit of users whose systems prompt them for intervention whenever a default configuration file is changed. Making this change allows us to update torrc.sample to be a more generally useful "sample torrc".
Major bug fixes (directory authorities):
Do not assign the HSDir flag to relays if they are not Valid, or currently hibernating. Fixes #12573. Bugfix on tor-0.2.0.10-alpha
Major bug fixes (directory bandwidth performance):
Don't flush the zlib buffer aggressively when compressing directory information for clients. This should save about 7% of the bandwidth currently used for compressed descriptors and microdescriptors. Fixes bug 11787; bug fix on 0.1.1.23.
Minor features (security, memory wiping):
Ensure we securely wipe keys from memory after crypto_digest_get_digest and init_curve25519_keypair_from_file have finished using them. Resolves ticket 13477.
Minor features (security, out-of-memory handling):
When handling an out-of-memory condition, allocate less memory for temporary data structures. Fixes issue 10115.
When handling an out-of-memory condition, consider more types of buffers, including those on directory connections, and zlib buffers. Resolves ticket 11792.
Minor features:
When identity keypair is generated for first time, log a congratulatory message that links to the new relay lifecycle document. Implements feature 10427.
Minor features (client):
Clients are now willing to send optimistic data (before they receive a 'connected' cell) to relays of any version. (Relays without support for optimistic data are no longer supported on the Tor network.) Resolves ticket 13153.
Minor features (directory authorities):
Don't list relays with a bandwidth estimate of 0 in the consensus. Implements a feature proposed during discussion of bug 13000.
In tor-gencert, report an error if the user provides the same argument more than once.
If a directory authority can't find a best consensus method in the votes that it holds, it now falls back to its favorite consensus method. Previously, it fell back to method 1. Neither of these is likely to get enough signatures, but "fall back to favorite" doesn't require us to maintain support an obsolete consensus method. Implements part of proposal 215.
Minor features (logging):
On Unix-like systems, you can now use named pipes as the target of the Log option, and other options that try to append to files. Closes ticket 12061. Patch from "carlo von lynX".
When opening a log file at startup, send it every log message that we generated between startup and opening it. Previously, log messages that were generated before opening the log file were only logged to stdout. Closes ticket 6938.
Add a TruncateLogFile option to overwrite logs instead of appending to them. Closes ticket #5583.
Minor features (portability, Solaris):
Threads are no longer disabled by default on Solaris; we believe that the versions of Solaris with broken threading support are all obsolete by now. Resolves ticket 9495.
Minor features (relay):
Re-check our address after we detect a changed IP address from getsockname(). This ensures that the controller command "GETINFO address" will report the correct value. Resolves ticket 11582. Patch from "ra".
A new AccountingRule option lets Relays set whether they'd like AccountingMax to be applied separately to inbound and outbound traffic, or applied to the sum of inbound and outbound traffic. Resolves ticket 961. Patch by "chobe".
Minor features (testing networks):
Add the TestingDirAuthVoteExit option, which lists nodes to assign the "Exit" flag regardless of their uptime, bandwidth, or exit policy. TestingTorNetwork must be set for this option to have any effect. Previously, authorities would take up to 35 minutes to give nodes the Exit flag in a test network. Partially implements ticket 13161.
Minor features (validation):
Check all date/time values passed to tor_timegm and parse_rfc1123_time for validity, taking leap years into account. Improves HTTP header validation. Implemented with bug 13476.
In correct_tm(), limit the range of values returned by system localtime(_r) and gmtime(_r) to be between the years 1 and 8099. This means we don't have to deal with negative or too large dates, even if a clock is wrong. Otherwise we might fail to read a file written by us which includes such a date. Fixes bug 13476.
Minor bug fixes (bridge clients):
When configured to use a bridge without an identity digest (not recommended), avoid launching an extra channel to it when bootstrapping. Fixes bug 7733; bug fix on 0.2.4.4-alpha.
Minor bug fixes (bridges):
When DisableNetwork is set, do not launch pluggable transport plugins, and if any are running, terminate them. Fixes bug 13213; bug fix on 0.2.3.6-alpha.
Minor bug fixes (C correctness):
Fix several instances of possible integer overflow/underflow/NaN. Fixes bug 13104; bug fix on 0.2.3.1-alpha and later. Patches from "teor".
In circuit_build_times_calculate_timeout() in circuitstats.c, avoid dividing by zero in the pareto calculations. This traps under clang's "undefined-trap" sanitizer. Fixes bug 13290; bug fix on tor-0.2.2.2-alpha.
Fix an integer overflow in format_time_interval(). Fixes bug 13393; bug fix on 0.2.0.10-alpha.
Set the correct day of year value when the system's localtime(_r) or gmtime(_r) functions fail to set struct tm. Not externally visible. Fixes bug 13476; bug fix on 0.0.2pre14.
Avoid unlikely signed integer overflow in tor_timegm on systems with 32-bit time_t. Fixes bug 13476; bug fix on 0.0.2pre14.
Minor bug fixes (client):
Fix smartlist_choose_node_by_bandwidth() so that relays with the BadExit flag are not considered worthy candidates. Fixes bug 13066; bug fix on 0.1.2.3-alpha.
Use the consensus schedule for downloading consensuses, and not the generic schedule. Fixes bug 11679; bug fix on 0.2.2.6-alpha.
Handle unsupported or malformed SOCKS5 requests properly by responding with the appropriate error message before closing the connection. Fixes bugs 12971 and 13314; bug fix on 0.0.2pre13.
Minor bug fixes (client, torrc):
Stop modifying the value of our DirReqStatistics torrc option just because we're not a bridge or relay. This bug was causing Tor Browser users to write "DirReqStatistics 0" in their torrc files as if they had chosen to change the config. Fixes bug 4244; bug fix on 0.2.3.1-alpha.
When GeoIPExcludeUnkonwn is enabled, do not incorrectly decide that our options have changed every time we SIGHUP. Fixes bug 9801; bug fix on 0.2.4.10-alpha. Patch from "qwerty1".
Minor bug fixes (controller):
Return an error when the second or later arguments of the "setevents" controller command are invalid events. Previously we would return success while silently skipping invalid events. Fixes bug 13205; bug fix on 0.2.3.2-alpha. Reported by "fpxnns".
Minor bug fixes (directory system):
Always believe that v3 directory authorities serve extra-info documents, whether they advertise "caches-extra-info" or not. Fixes part of bug 11683; bug fix on 0.2.0.1-alpha.
When running as a v3 directory authority, advertise that you serve extra-info documents so that clients who want them can find them from you too. Fixes part of bug 11683; bug fix on 0.2.0.1-alpha.
Check the BRIDGE_DIRINFO flag bitwise rather than using equality. Previously, directories offering BRIDGE_DIRINFO and some other flag (i.e. microdescriptors or extrainfo) would be ignored when looking for bridges. Partially fixes bug 13163; bug fix on 0.2.0.7-alpha.
Minor bug fixes (networking):
Check for orconns and use connection_or_close_for_error() rather than connection_mark_for_close() directly in the getsockopt() failure case of connection_handle_write_impl(). Fixes bug 11302; bug fix on 0.2.4.4-alpha.
Minor bug fixes (relay):
When generating our family list, remove spaces from around the entries. Fixes bug 12728; bug fix on 0.2.1.7-alpha.
If our previous bandwidth estimate was 0 bytes, allow publishing a new relay descriptor immediately. Fixes bug 13000; bug fix on 0.1.1.6-alpha.
Minor bug fixes (testing networks):
Fix TestingDirAuthVoteGuard to properly give out Guard flags in a testing network. Fixes bug 13064; bug fix on 0.2.5.2-alpha.
Stop using the default authorities in networks which provide both AlternateDirAuthority and AlternateBridgeAuthority. Partially fixes bug 13163; bug fix on 0.2.0.13-alpha.
Minor bug fixes (testing):
Stop spawn test failures due to a race condition between the SIGCHLD handler updating the process status, and the test reading it. Fixes bug 13291; bug fix on 0.2.3.3-alpha.
Minor bug fixes (testing, Windows):
Avoid passing an extra backslash when creating a temporary directory for running the unit tests on Windows. Fixes bug 12392; bug fix on 0.2.2.25-alpha. Patch from Gisle Vanem.
Minor bug fixes (windows):
Remove code to special-case handling of NTE_BAD_KEYSET when acquiring windows CryptoAPI context. This error can't actually occur for the parameters we're providing. Fixes bug 10816; bug fix on 0.0.2pre26.
Minor bug fixes (zlib):
Avoid truncating a zlib stream when trying to finalize it with an empty output buffer. Fixes bug 11824; bug fix on 0.1.1.23.
Build fixes:
Allow our configure script to build correctly with autoconf 2.62 again. Fixes bug 12693; bug fix on 0.2.5.2-alpha.
Improve the error message from ./configure to make it clear that when asciidoc has not been found, the user will have to either add --disable-asciidoc argument or install asciidoc. Resolves ticket 13228.
Code simplification and refactoring:
Change the entry_is_live() function to take named bitfield elements instead of an unnamed list of booleans. Closes ticket 12202.
Refactor and unit-test entry_is_time_to_retry() in entrynodes.c. Resolves ticket 12205.
Use calloc and reallocarray functions in preference to multiply- then-malloc. This makes it less likely for us to fall victim to an integer overflow attack when allocating. Resolves ticket 12855.
Use the standard macro name SIZE_MAX, instead of our own SIZE_T_MAX.
Document usage of the NO_DIRINFO and ALL_DIRINFO flags clearly in functions which take them as arguments. Replace 0 with NO_DIRINFO in a function call for clarity. Seeks to prevent future issues like 13163.
Avoid 4 null pointer errors under clang shallow analysis by using tor_assert() to prove that the pointers aren't null. Fixes bug 13284.
Rework the API of policies_parse_exit_policy() to use a bitmask to represent parsing options, instead of a confusing mess of booleans. Resolves ticket 8197.
Introduce a helper function to parse ExitPolicy in or_options_t structure.
Documentation:
Add a doc/TUNING document with tips for handling large numbers of TCP connections when running busy Tor relay. Update the warning message to point to this file when running out of sockets operating system is allowing to use simultaneously. Resolves ticket 9708.
Removed code:
We no longer remind the user about configuration options that have been obsolete since 0.2.3.x or earlier. Patch by Adrien Bak.
Removed features:
Remove the --disable-curve25519 configure option. Relays and clients now are required to support curve25519 and the ntor handshake.
The old "StrictEntryNodes" and "StrictExitNodes" options, which used to be deprecated synonyms for "StrictNodes", are now marked obsolete. Resolves ticket 12226.
The "AuthDirRejectUnlisted" option no longer has any effect, as the fingerprints file (approved-routers) has been deprecated.
Directory authorities do not support being Naming dirauths anymore. The "NamingAuthoritativeDir" config option is now obsolete.
Directory authorities do not support giving out the BadDirectory flag anymore.
Clients don't understand the BadDirectory flag in the consensus anymore, and ignore it.
Testing:
Refactor the function that chooses guard nodes so that it can more easily be tested; write some tests for it.
Fix and re-enable the fgets_eagain unit test. Fixes bug 12503; bug fix on 0.2.3.1-alpha. Patch from "cypherpunks."
Create unit tests for format_time_interval(). With bug 13393.
Add unit tests for tor_timegm signed overflow, tor_timegm and parse_rfc1123_time validity checks, correct_tm year clamping. Unit tests (visible) fixes in bug 13476.
Add a "coverage-html" make target to generate HTML-visualized coverage results when building with --enable-coverage. (Requires lcov.) Patch from Kevin Murray.
Enable the backtrace handler (where supported) when running the unit tests.
Revise all unit tests that used the legacy test_* macros to instead use the recommended tt_* macros. This patch was generated with coccinelle, to avoid manual errors. Closes ticket 13119.
Distribution (systemd):
systemd unit file: only allow tor to write to /var/lib/tor and /var/log/tor. The rest of the filesystem is accessible for reading only. Patch by intrigeri; resolves ticket 12751.
systemd unit file: ensure that the process and all its children can never gain new privileges. Patch by intrigeri; resolves ticket 12939.
systemd unit file: set up /var/run/tor as writable for the Tor service. Patch by intrigeri; resolves ticket 13196.
Removed features (directory authorities):
Remove code that prevented authorities from listing Tor relays affected by CVE-2011-2769 as guards. These relays are already rejected altogether due to the minimum version requirement of 0.2.3.16-alpha. Closes ticket 13152.
Directory authorities no longer advertise or support consensus methods 1 through 12 inclusive. These consensus methods were obsolete and/or insecure: maintaining the ability to support them served no good purpose. Implements part of proposal 215; closes ticket 10163.
Testing (test-network.sh):
Stop using "echo -n", as some shells' built-in echo doesn't support "-n". Instead, use "/bin/echo -n". Partially fixes bug 13161.
Stop an apparent test-network hang when used with make -j2. Fixes bug 13331.
Add a --delay option to test-network.sh, which configures the delay before the chutney network tests for data transmission. Partially implements ticket 13161.

New in Tor 0.2.5.10 (Oct 24, 2014)

New in Tor 0.2.5.9 RC (Oct 21, 2014)

New in Tor 0.2.4.25 (Oct 21, 2014)

New in Tor 0.2.4.24 (Sep 23, 2014)

New in Tor 0.2.5.8 RC (Sep 23, 2014)

New in Tor 0.2.5.7 RC (Sep 12, 2014)

Tor 0.2.5.7-rc fixes several regressions from earlier in the 0.2.5.x release series, and some long-standing bugs related to ORPort reachability testing and failure to send CREATE cells. It is the first release candidate for the Tor 0.2.5.x series.
Major bug fixes (client, startup):
Start making circuits as soon as DisabledNetwork is turned off. When Tor started with DisabledNetwork set, it would correctly conclude that it shouldn't build circuits, but it would mistakenly cache this conclusion, and continue believing it even when DisableNetwork is set to 0. Fixes the bug introduced by the fix for bug 11200; bugfix on 0.2.5.4-alpha.
Resume expanding abbreviations for command-line options. The fix for bug 4647 accidentally removed our hack from bug 586 that rewrote HashedControlPassword to __HashedControlSessionPassword when it appears on the commandline (which allowed the user to set her own HashedControlPassword in the torrc file while the controller generates a fresh session password for each run). Fixes bug 12948; bugfix on 0.2.5.1-alpha.
Warn about attempts to run hidden services and relays in the same process: that's probably not a good idea. Closes ticket 12908.
Major bug fixes (relay):
Avoid queuing or sending destroy cells for circuit ID zero when we fail to send a CREATE cell. Fixes bug 12848; bugfix on 0.0.8pre1. Found and fixed by "cypherpunks".
Fix ORPort reachability detection on relays running behind a proxy, by correctly updating the "local" mark on the controlling channel when changing the address of an or_connection_t after the handshake. Fixes bug 12160; bugfix on 0.2.4.4-alpha.
Minor features (bridge):
Add an ExtORPortCookieAuthFileGroupReadable option to make the cookie file for the ExtORPort g+r by default.
Minor features (geoip):
Update geoip and geoip6 to the August 7 2014 Maxmind GeoLite2 Country database.
Minor bug fixes (logging):
Reduce the log severity of the "Pluggable transport proxy does not provide any needed transports and will not be launched." message, since Tor Browser includes several ClientTransportPlugin lines in its torrc-defaults file, leading every Tor Browser user who looks at her logs to see these notices and wonder if they're dangerous. Resolves bug 13124; bugfix on 0.2.5.3-alpha.
Downgrade "Unexpected onionskin length after decryption" warning to a protocol-warn, since there's nothing relay operators can do about a client that sends them a malformed create cell. Resolves bug 12996; bugfix on 0.0.6rc1.
Log more specific warnings when we get an ESTABLISH_RENDEZVOUS cell on a cannibalized or non-OR circuit. Resolves ticket 12997.
When logging information about an EXTEND2 or EXTENDED2 cell, log their names correctly. Fixes part of bug 12700; bugfix on 0.2.4.8-alpha.
When logging information about a relay cell whose command we don't recognize, log its command as an integer. Fixes part of bug 12700; bugfix on 0.2.1.10-alpha.
Escape all strings from the directory connection before logging them. Fixes bug 13071; bugfix on 0.1.1.15. Patch from "teor".
Minor bug fixes (controller):
Restore the functionality of CookieAuthFileGroupReadable. Fixes bug 12864; bugfix on 0.2.5.1-alpha.
Actually send TRANSPORT_LAUNCHED and HS_DESC events to controllers. Fixes bug 13085; bugfix on 0.2.5.1-alpha. Patch by "teor".
Minor bug fixes (compilation):
Fix compilation of test.h with MSVC. Patch from Gisle Vanem; bugfix on 0.2.5.5-alpha.
Make the nmake make files work again. Fixes bug 13081. Bugfix on 0.2.5.1-alpha. Patch from "NewEraCracker".
In routerlist_assert_ok(), don't take the address of a routerinfo's cache_info member unless that routerinfo is non-NULL. Fixes bug 13096; bugfix on 0.1.1.9-alpha. Patch by "teor".
Fix a large number of false positive warnings from the clang analyzer static analysis tool. This should make real warnings easier for clang analyzer to find. Patch from "teor". Closes ticket 13036.
Distribution (systemd):
Verify configuration file via ExecStartPre in the systemd unit file. Patch from intrigeri; resolves ticket 12730.
Explicitly disable RunAsDaemon in the systemd unit file. Our current systemd unit uses "Type = simple", so systemd does not expect tor to fork. If the user has "RunAsDaemon 1" in their torrc, then things won't work as expected. This is e.g. the case on Debian (and derivatives), since there we pass "--defaults-torrc /usr/share/tor/tor-service-defaults-torrc" (that contains "RunAsDaemon 1") by default. Patch by intrigeri; resolves ticket 12731.
Documentation:
Adjust the URLs in the README to refer to the new locations of several documents on the website. Fixes bug 12830. Patch from Matt Pagan.
Document 'reject6' and 'accept6' ExitPolicy entries. Resolves ticket 12878.

New in Tor 0.2.5.6 Alpha (Jul 30, 2014)

Tor 0.2.5.6-alpha brings us a big step closer to slowing down the risk from guard rotation, and fixes a variety of other issues to get us closer to a release candidate.
Major features (also in 0.2.4.23):
Make the number of entry guards configurable via a new NumEntryGuards consensus parameter, and the number of directory guards configurable via a new NumDirectoryGuards consensus parameter. Implements ticket 12688.
Major bug fixes (also in 0.2.4.23):
Fix a bug in the bounds-checking in the 32-bit curve25519-donna implementation that caused incorrect results on 32-bit implementations when certain malformed inputs were used along with a small class of private ntor keys. This bug does not currently appear to allow an attacker to learn private keys or impersonate a Tor server, but it could provide a means to distinguish 32-bit Tor implementations from 64-bit Tor implementations. Fixes bug 12694; bug fix on 0.2.4.8-alpha. Bug found by Robert Ransom; fix from Adam Langley.
Major bug fixes:
Perform circuit cleanup operations even when circuit construction operations are disabled (because the network is disabled, or because there isn't enough directory information). Previously, when we were not building predictive circuits, we were not closing expired circuits either. Fixes bug 8387; bug fix on 0.1.1.11-alpha. This bug became visible in 0.2.4.10-alpha when we became more strict about when we have "enough directory information to build circuits".
Minor features:
Authorities now assign the Guard flag to the fastest 25% of the network (it used to be the fastest 50%). Also raise the consensus weight that guarantees the Guard flag from 250 to 2000. For the current network, this results in about 1100 guards, down from 2500. This step paves the way for moving the number of entry guards down to 1 (proposal 236) while still providing reasonable expected performance for most users. Implements ticket 12690.
Update geoip and geoip6 to the July 10 2014 Maxmind GeoLite2 Country database.
Slightly enhance the diagnostic message for bug 12184.
Minor bug fixes (also in 0.2.4.23):
Warn and drop the circuit if we receive an inbound 'relay early' cell. Those used to be normal to receive on hidden service circuits due to bug 1038, but the buggy Tor versions are long gone from the network so we can afford to resume watching for them. Resolves the rest of bug 1038; bug fix on 0.2.1.19.
Correct a confusing error message when trying to extend a circuit via the control protocol but we don't know a descriptor or microdescriptor for one of the specified relays. Fixes bug 12718; bug fix on 0.2.3.1-alpha.
Minor bug fixes:
Fix compilation when building with bufferevents enabled. (This configuration is still not expected to work, however.) Fixes bugs 12438, 12474, 11578; bug fixes on 0.2.5.1-alpha and 0.2.5.3-alpha. Patches from Anthony G. Basile and Sathyanarayanan Gunasekaran.
Compile correctly with builds and forks of OpenSSL (such as LibreSSL) that disable compression. Fixes bug 12602; bug fix on 0.2.1.1-alpha. Patch from "dhill".

New in Tor 0.2.4.23 (Jul 30, 2014)

Tor 0.2.4.23 brings us a big step closer to slowing down the risk from guard rotation, and also backports several important fixes from the Tor 0.2.5 alpha release series.
Major features:
Clients now look at the "usecreatefast" consensus parameter to decide whether to use CREATE_FAST or CREATE cells for the first hop of their circuit. This approach can improve security on connections where Tor's circuit handshake is stronger than the available TLS connection security levels, but the tradeoff is more computational load on guard relays. Implements proposal 221. Resolves ticket 9386.
Make the number of entry guards configurable via a new NumEntryGuards consensus parameter, and the number of directory guards configurable via a new NumDirectoryGuards consensus parameter. Implements ticket 12688.
Major bug fixes:
Fix a bug in the bounds-checking in the 32-bit curve25519-donna implementation that caused incorrect results on 32-bit implementations when certain malformed inputs were used along with a small class of private ntor keys. This bug does not currently appear to allow an attacker to learn private keys or impersonate a Tor server, but it could provide a means to distinguish 32-bit Tor implementations from 64-bit Tor implementations. Fixes bug 12694; bugfix on 0.2.4.8-alpha. Bug found by Robert Ransom; fix from Adam Langley.
Minor bug fixes:
Warn and drop the circuit if we receive an inbound 'relay early' cell. Those used to be normal to receive on hidden service circuits due to bug 1038, but the buggy Tor versions are long gone from the network so we can afford to resume watching for them. Resolves the rest of bug 1038; bugfix on 0.2.1.19.
Correct a confusing error message when trying to extend a circuit via the control protocol but we don't know a descriptor or microdescriptor for one of the specified relays. Fixes bug 12718; bugfix on 0.2.3.1-alpha.
Avoid an illegal read from stack when initializing the TLS module using a version of OpenSSL without all of the ciphers used by the v2 link handshake. Fixes bug 12227; bugfix on 0.2.4.8-alpha. Found by "starlight".
Minor features:
Update geoip and geoip6 to the July 10 2014 Maxmind GeoLite2 Country database.

New in Tor 0.2.5.5 Alpha (Jul 2, 2014)

Tor 0.2.5.5-alpha fixes a wide variety of remaining issues in the Tor 0.2.5.x release series, including a couple of DoS issues, some performance regressions, a large number of bugs affecting the Linux seccomp2 sandbox code, and various other bug fixes. It also adds diagnostic bug fixes for a few tricky issues that we're trying to track down.
Major features (security, traffic analysis resistance):
Several major improvements to the algorithm used to decide when to close TLS connections. Previous versions of Tor closed connections at a fixed interval after the last time a non-padding cell was sent over the connection, regardless of the target of the connection. Now, we randomize the intervals by adding up to 50% of their base value, we measure the length of time since connection last had at least one circuit, and we allow connections to known ORs to remain open a little longer (15 minutes instead of 3 minutes minimum). These changes should improve Tor's resistance against some kinds of traffic analysis, and lower some overhead from needlessly closed connections. Fixes ticket 6799. Incidentally fixes ticket 12023; bugfix on 0.2.5.1-alpha.
Major bug fixes (security, OOM, new since 0.2.5.4-alpha, also in 0.2.4.22):
Fix a memory leak that could occur if a microdescriptor parse fails during the tokenizing step. This bug could enable a memory exhaustion attack by directory servers. Fixes bug 11649; bugfix on 0.2.2.6-alpha.
Major bug fixes (security, directory authorities):
Directory authorities now include a digest of each relay's identity key as a part of its microdescriptor.
This is a workaround for bug 11743 (reported by "cypherpunks"), where Tor clients do not support receiving multiple microdescriptors with the same SHA256 digest in the same consensus. When clients receive a consensus like this, they only use one of the relays. Without this fix, a hostile relay could selectively disable some client use of target relays by constructing a router descriptor with a different identity and the same microdescriptor parameters and getting the authorities to list it in a microdescriptor consensus. This fix prevents an attacker from causing a microdescriptor collision, because the router's identity is not forgeable.
Major bug fixes (relay):
Use a direct dirport connection when uploading non-anonymous descriptors to the directory authorities. Previously, relays would incorrectly use tunnel connections under a fairly wide variety of circumstances. Fixes bug 11469; bugfix on 0.2.4.3-alpha.
When a circuit accidentally has the same circuit ID for its forward and reverse direction, correctly detect the direction of cells using that circuit. Previously, this bug made roughly one circuit in a million non-functional. Fixes bug 12195; this is a bugfix on every version of Tor.
Major bug fixes (client, pluggable transports):
When managing pluggable transports, use OS notification facilities to learn if they have crashed, and don't attempt to kill any process that has already exited. Fixes bug 8746; bugfix on 0.2.3.6-alpha.
Minor features (diagnostic):
When logging a warning because of bug 7164, additionally check the hash table for consistency (as proposed on ticket 11737). This may help diagnose bug 7164.
When we log a heartbeat, log how many one-hop circuits we have that are at least 30 minutes old, and log status information about a few of them. This is an attempt to track down bug 8387.
When encountering an unexpected CR while writing text to a file on Windows, log the name of the file. Should help diagnosing bug 11233.
Give more specific warnings when a client notices that an onion handshake has failed. Fixes ticket 9635.
Add significant new logging code to attempt to diagnose bug 12184, where relays seem to run out of available circuit IDs.
Improve the diagnostic log message for bug 8387 even further to try to improve our odds of figuring out why one-hop directory circuits sometimes do not get closed.
Minor features (security, memory management):
Memory allocation tricks (mempools and buffer freelists) are now disabled by default. You can turn them back on with --enable-mempools and --enable-buf-freelists respectively. We're disabling these features because malloc performance is good enough on most platforms, and a similar feature in OpenSSL exacerbated exploitation of the Heartbleed attack. Resolves ticket 11476.
Minor features (security):
Apply the secure SipHash-2-4 function to the hash table mapping circuit IDs and channels to circuits. We missed this one when we were converting all the other hash functions to use SipHash back in 0.2.5.3-alpha. Resolves ticket 11750.
Minor features (build):
The configure script has a --disable-seccomp option to turn off support for libseccomp on systems that have it, in case it (or Tor's use of it) is broken. Resolves ticket 11628.
Minor features (other):
Update geoip and geoip6 to the June 4 2014 Maxmind GeoLite2 Country database.
Minor bug fixes (security, new since 0.2.5.4-alpha, also in 0.2.4.22):
When running a hidden service, do not allow TunneledDirConns 0; this will keep the hidden service from running, and also make it publish its descriptors directly over HTTP. Fixes bug 10849; bugfix on 0.2.1.1-alpha.
Minor bug fixes (performance):
Avoid a bug where every successful connection made us recompute the flag telling us whether we have sufficient information to build circuits. Previously, we would forget our cached value whenever we successfully opened a channel (or marked a router as running or not running for any other reason), regardless of whether we had previously believed the router to be running. This forced us to run an expensive update operation far too often. Fixes bug 12170; bugfix on 0.1.2.1-alpha.
Avoid using tor_memeq() for checking relay cell integrity. This removes a possible performance bottleneck. Fixes part of bug 12169; bugfix on 0.2.1.31.
Minor bug fixes (compilation):
Fix compilation of test_status.c when building with MVSC. Bugfix on 0.2.5.4-alpha. Patch from Gisle Vanem.
Resolve GCC complaints on OpenBSD about discarding constness in TO_{ORIGIN,OR}_CIRCUIT functions. Fixes part of bug 11633; bugfix on 0.1.1.23. Patch from Dana Koch.
Resolve clang complaints on OpenBSD with -Wshorten-64-to-32 due to treatment of long and time_t as comparable types. Fixes part of bug 11633. Patch from Dana Koch.
Make Tor compile correctly with --disable-buf-freelists. Fixes bug 11623; bugfix on 0.2.5.3-alpha.
When deciding whether to build the 64-bit curve25519 implementation, detect platforms where we can compile 128-bit arithmetic but cannot link it. Fixes bug 11729; bugfix on 0.2.4.8-alpha. Patch from "conradev".
Fix compilation when DNS_CACHE_DEBUG is enabled. Fixes bug 11761; bugfix on 0.2.3.13-alpha. Found by "cypherpunks".
Fix compilation with dmalloc. Fixes bug 11605; bugfix on 0.2.4.10-alpha.
Minor bug fixes (Directory server):
When sending a compressed set of descriptors or microdescriptors, make sure to finalize the zlib stream. Previously, we would write all the compressed data, but if the last descriptor we wanted to send was missing or too old, we would not mark the stream as finished. This caused problems for decompression tools. Fixes bug 11648; bugfix on 0.1.1.23.
Minor bug fixes (pluggable transports):
Enable the ExtORPortCookieAuthFile option, to allow changing the default location of the authentication token for the extended OR Port as used by sever-side pluggable transports. We had implemented this option before, but the code to make it settable had been omitted. Fixes bug 11635; bugfix on 0.2.5.1-alpha.
Avoid another 60-second delay when starting Tor in a pluggable- transport-using configuration when we already have cached descriptors for our bridges. Fixes bug 11965; bugfix on 0.2.3.6-alpha.
Minor bug fixes (client):
Avoid "Tried to open a socket with DisableNetwork set" warnings when starting a client with bridges configured and DisableNetwork set. (Tor launcher starts Tor with DisableNetwork set the first time it runs.) Fixes bug 10405; bugfix on 0.2.3.9-alpha.
Minor bug fixes (testing):
The Python parts of the test scripts now work on Python 3 as well as Python 2, so systems where '/usr/bin/python' is Python 3 will no longer have the tests break. Fixes bug 11608; bugfix on 0.2.5.2-alpha.
When looking for versions of python that we could run the tests with, check for "python2.7" and "python3.3"; previously we were only looking for "python", "python2", and "python3". Patch from Dana Koch. Fixes bug 11632; bugfix on 0.2.5.2-alpha.
Fix all valgrind warnings produced by the unit tests. There were over a thousand memory leak warnings previously, mostly produced by forgetting to free things in the unit test code. Fixes bug 11618, bug fixes on many versions of Tor.
Minor bug fixes (tor-fw-helper):
Give a correct log message when tor-fw-helper fails to launch. (Previously, we would say something like "tor-fw-helper sent us a string we could not parse".) Fixes bug 9781; bugfix on 0.2.4.2-alpha.
Minor bug fixes (relay, threading):
Check return code on spawn_func() in cpuworker code, so that we don't think we've spawned a nonworking cpuworker and write junk to it forever. Fix related to bug 4345; bugfix on all released Tor versions. Found by "skruffy".
Use a pthread_attr to make sure that spawn_func() cannot return an error while at the same time launching a thread. Fix related to bug 4345; bugfix on all released Tor versions. Reported by "cypherpunks".
Minor bug fixes (relay, oom prevention):
Correctly detect the total available system memory. We tried to do this in 0.2.5.4-alpha, but the code was set up to always return an error value, even on success. Fixes bug 11805; bugfix on 0.2.5.4-alpha.
Minor bug fixes (relay, other):
We now drop CREATE cells for already-existent circuit IDs and for zero-valued circuit IDs, regardless of other factors that might otherwise have called for DESTROY cells. Fixes bug 12191; bugfix on 0.0.8pre1.
Avoid an illegal read from stack when initializing the TLS module using a version of OpenSSL without all of the ciphers used by the v2 link handshake. Fixes bug 12227; bugfix on 0.2.4.8-alpha. Found by "starlight".
When rejecting DATA cells for stream_id zero, still count them against the circuit's deliver window so that we don't fail to send a SENDME. Fixes bug 11246; bugfix on 0.2.4.10-alpha.
Minor bug fixes (logging):
Fix a misformatted log message about delayed directory fetches. Fixes bug 11654; bugfix on 0.2.5.3-alpha.
Squelch a spurious LD_BUG message "No origin circuit for successful SOCKS stream" in certain hidden service failure cases; fixes bug 10616.
Distribution:
Include a tor.service file in contrib/dist for use with systemd. Some distributions will be able to use this file unmodified; others will need to tweak it, or write their own. Patch from Jamie Nguyen; resolves ticket 8368.
Documentation:
Clean up several option names in the manpage to match their real names, add the missing documentation for a couple of testing and directory authority options, remove the documentation for a V2-directory fetching option that no longer exists. Resolves ticket 11634.
Correct the documenation so that it lists the correct directory for the stats files. (They are in a subdirectory called "stats", not "status".)
In the manpage, move more authority-only options into the directory authority section so that operators of regular directory caches don't get confused.
Package cleanup:
The contrib directory has been sorted and tidied. Before, it was an unsorted dumping ground for useful and not-so-useful things. Now, it is divided based on functionality, and the items which seemed to be nonfunctional or useless have been removed. Resolves ticket 8966; based on patches from "rl1987".
Removed code:
Remove /tor/dbg-stability.txt URL that was meant to help debug WFU and MTBF calculations, but that nobody was using. Fixes #11742.
The TunnelDirConns and PreferTunnelledDirConns options no longer exist; tunneled directory connections have been available since 0.1.2.5-alpha, and turning them off is not a good idea. This is a brute-force fix for 10849, where "TunnelDirConns 0" would break hidden services.

New in Tor 0.2.4.22 (May 17, 2014)

Tor 0.2.4.22 backports numerous high-priority fixes from the Tor 0.2.5 alpha release series. These include blocking all authority signing keys that may have been affected by the OpenSSL "heartbleed" bug, choosing a far more secure set of TLS ciphersuites by default, closing a couple of memory leaks that could be used to run a target relay out of RAM, and several others.
Major features (security, backport from 0.2.5.4-alpha):
Block authority signing keys that were used on authorities vulnerable to the "heartbleed" bug in OpenSSL (CVE-2014-0160). (We don't have any evidence that these keys _were_ compromised; we're doing this to be prudent.) Resolves ticket 11464.
Major bug fixes (security, OOM):
Fix a memory leak that could occur if a microdescriptor parse fails during the tokenizing step. This bug could enable a memory exhaustion attack by directory servers. Fixes bug 11649; bugfix on 0.2.2.6-alpha.
Major bug fixes (TLS cipher selection, backport from 0.2.5.4-alpha):
The relay ciphersuite list is now generated automatically based on uniform criteria, and includes all OpenSSL ciphersuites with acceptable strength and forward secrecy. Previously, we had left some perfectly fine ciphersuites unsupported due to omission or typo. Resolves bugs 11513, 11492, 11498, 11499. Bugs reported by 'cypherpunks'. Bugfix on 0.2.4.8-alpha.
Relays now trust themselves to have a better view than clients of which TLS ciphersuites are better than others. (Thanks to bug 11513, the relay list is now well-considered, whereas the client list has been chosen mainly for anti-fingerprinting purposes.) Relays prefer: AES over 3DES; then ECDHE over DHE; then GCM over CBC; then SHA384 over SHA256 over SHA1; and last, AES256 over AES128. Resolves ticket 11528.
Clients now try to advertise the same list of ciphersuites as Firefox 28. This change enables selection of (fast) GCM ciphersuites, disables some strange old ciphers, and stops advertising the ECDH (not to be confused with ECDHE) ciphersuites. Resolves ticket 11438.
Minor bug fixes (configuration, security):
When running a hidden service, do not allow TunneledDirConns 0: trying to set that option together with a hidden service would otherwise prevent the hidden service from running, and also make it publish its descriptors directly over HTTP. Fixes bug 10849; bugfix on 0.2.1.1-alpha.
Minor bug fixes (controller, backport from 0.2.5.4-alpha):
Avoid sending a garbage value to the controller when a circuit is cannibalized. Fixes bug 11519; bugfix on 0.2.3.11-alpha.
Minor bug fixes (exit relay, backport from 0.2.5.4-alpha):
Stop leaking memory when we successfully resolve a PTR record. Fixes bug 11437; bugfix on 0.2.4.7-alpha.
Minor bug fixes (bridge client, backport from 0.2.5.4-alpha):
Avoid 60-second delays in the bootstrapping process when Tor is launching for a second time while using bridges. Fixes bug 9229; bugfix on 0.2.0.3-alpha.
Minor bug fixes (relays and bridges, backport from 0.2.5.4-alpha):
Give the correct URL in the warning message when trying to run a relay on an ancient version of Windows. Fixes bug 9393.
Minor bug fixes (compilation):
Fix a compilation error when compiling with --disable-curve25519. Fixes bug 9700; bugfix on 0.2.4.17-rc.
Minor bug fixes:
Downgrade the warning severity for the the "md was still referenced 1 node(s)" warning. Tor 0.2.5.4-alpha has better code for trying to diagnose this bug, and the current warning in earlier versions of tor achieves nothing useful. Addresses warning from bug 7164.
Minor features (log verbosity, backport from 0.2.5.4-alpha):
When we run out of usable circuit IDs on a channel, log only one warning for the whole channel, and describe how many circuits there were on the channel. Fixes part of ticket 11553.
Minor features (security, backport from 0.2.5.4-alpha):
Decrease the lower limit of MaxMemInCellQueues to 256 MBytes (but leave the default at 8GBytes), to better support Raspberry Pi users. Fixes bug 9686; bugfix on 0.2.4.14-alpha.
Documentation (backport from 0.2.5.4-alpha):
Correctly document that we search for a system torrc file before looking in ~/.torrc. Fixes documentation side of 9213; bugfix on 0.2.3.18-rc.

New in Tor 0.2.5.4 Alpha (Apr 28, 2014)

Tor 0.2.5.4-alpha includes several security and performance improvements for clients and relays, including blacklisting authority signing keys that were used while susceptible to the OpenSSL "heartbleed" bug, fixing two expensive functions on busy relays, improved TLS ciphersuite preference lists, support for run-time hardening on compilers that support AddressSanitizer, and more work on the Linux sandbox code.
There are also several usability fixes for clients (especially clients that use bridges), two new TransPort protocols supported (one on OpenBSD, one on FreeBSD), and various other bugfixes.
This release marks end-of-life for Tor 0.2.2.x; those Tor versions have accumulated many known flaws; everyone should upgrade.
Major features (security):
If you don't specify MaxMemInQueues yourself, Tor now tries to pick a good value based on your total system memory. Previously, the default was always 8 GB. You can still override the default by setting MaxMemInQueues yourself. Resolves ticket 11396.
Block authority signing keys that were used on authorities vulnerable to the "heartbleed" bug in OpenSSL (CVE-2014-0160). (We don't have any evidence that these keys _were_ compromised; we're doing this to be prudent.) Resolves ticket 11464.
Major features (relay performance):
Speed up server-side lookups of rendezvous and introduction point circuits by using hashtables instead of linear searches. These functions previously accounted between 3 and 7% of CPU usage on some busy relays. Resolves ticket 9841.
Avoid wasting CPU when extending a circuit over a channel that is nearly out of circuit IDs. Previously, we would do a linear scan over possible circuit IDs before finding one or deciding that we had exhausted our possibilities. Now, we try at most 64 random circuit IDs before deciding that we probably won't succeed. Fixes a possible root cause of ticket 11553.
Major features (seccomp2 sandbox, Linux only):
The seccomp2 sandbox can now run a test network for multiple hours without crashing. The sandbox is still experimental, and more bugs will probably turn up. To try it, enable "Sandbox 1" on a Linux host. Resolves ticket 11351.
Strengthen sandbox code: the sandbox can now test the arguments for rename(), and blocks _sysctl() entirely. Resolves another part of ticket 11351.
When the sandbox blocks a system call, it now tries to log a stack trace before exiting. Resolves ticket 11465.
Major bugfixes (TLS cipher selection):
The relay ciphersuite list is now generated automatically based on uniform criteria, and includes all OpenSSL ciphersuites with acceptable strength and forward secrecy. Previously, we had left some perfectly fine ciphersuites unsupported due to omission or typo. Resolves bugs 11513, 11492, 11498, 11499. Bugs reported by 'cypherpunks'. Bugfix on 0.2.4.8-alpha.
Relays now trust themselves to have a better view than clients of which TLS ciphersuites are better than others. (Thanks to bug 11513, the relay list is now well-considered, whereas the client list has been chosen mainly for anti-fingerprinting purposes.) Relays prefer: AES over 3DES; then ECDHE over DHE; then GCM over CBC; then SHA384 over SHA256 over SHA1; and last, AES256 over AES128. Resolves ticket 11528.
Clients now try to advertise the same list of ciphersuites as Firefox 28. This change enables selection of (fast) GCM ciphersuites, disables some strange old ciphers, and stops advertising the ECDH (not to be confused with ECDHE) ciphersuites. Resolves ticket 11438.
Major bugfixes (bridge client):
Avoid 60-second delays in the bootstrapping process when Tor is launching for a second time while using bridges. Fixes bug 9229; bugfix on 0.2.0.3-alpha.
Minor features (transparent proxy, *BSD):
Support FreeBSD's ipfw firewall interface for TransPort ports on FreeBSD. To enable it, set "TransProxyType ipfw". Resolves ticket 10267; patch from "yurivict".
Support OpenBSD's divert-to rules with the pf firewall for transparent proxy ports. To enable it, set "TransProxyType pf-divert". This allows Tor to run a TransPort transparent proxy port on OpenBSD 4.4 or later without root privileges. See the pf.conf(5) manual page for information on configuring pf to use divert-to rules. Closes ticket 10896; patch from Dana Koch.
Minor features (security):
New --enable-expensive-hardening option to enable security hardening options that consume nontrivial amounts of CPU and memory. Right now, this includes AddressSanitizer and UbSan, which are supported in newer versions of GCC and Clang. Closes ticket 11477.
Minor features (log verbosity):
Demote the message that we give when a flushing connection times out for too long from NOTICE to INFO. It was usually meaningless. Resolves ticket 5286.
Don't log so many notice-level bootstrapping messages at startup about downloading descriptors. Previously, we'd log a notice whenever we learned about more routers. Now, we only log a notice at every 5% of progress. Fixes bug 9963.
Warn less verbosely when receiving a malformed ESTABLISH_RENDEZVOUS cell. Fixes ticket 11279.
When we run out of usable circuit IDs on a channel, log only one warning for the whole channel, and describe how many circuits there were on the channel. Fixes part of ticket 11553.
Minor features (relay):
If a circuit timed out for at least 3 minutes, check if we have a new external IP address, and publish a new descriptor with the new IP address if it changed. Resolves ticket 2454.
Minor features (controller):
Make the entire exit policy available from the control port via GETINFO exit-policy/*. Implements enhancement 7952. Patch from "rl1987".
Because of the fix for ticket 11396, the real limit for memory usage may no longer match the configured MaxMemInQueues value. The real limit is now exposed via GETINFO limits/max-mem-in-queues.
Minor features (bridge client):
Report a more useful failure message when we can't connect to a bridge because we don't have the right pluggable transport configured. Resolves ticket 9665. Patch from Fábio J. Bertinatto.
Minor features (diagnostic):
Add more log messages to diagnose bug 7164, which causes intermittent "microdesc_free() called but md was still referenced" warnings. We now include more information, to figure out why we might be cleaning a microdescriptor for being too old if it's still referenced by a live node_t object.
Minor bugfixes (client, DNSPort):
When using DNSPort, try to respond to AAAA requests with AAAA answers. Previously, we hadn't looked at the request type when deciding which answer type to prefer. Fixes bug 10468; bugfix on 0.2.4.7-alpha.
When receiving a DNS query for an unsupported record type, reply with no answer rather than with a NOTIMPL error. This behavior isn't correct either, but it will break fewer client programs, we hope. Fixes bug 10268; bugfix on 0.2.0.1-alpha. Original patch from "epoch".
Minor bugfixes (exit relay):
Stop leaking memory when we successfully resolve a PTR record. Fixes bug 11437; bugfix on 0.2.4.7-alpha.
Minor bugfixes (bridge client):
Stop accepting bridge lines containing hostnames. Doing so would cause clients to perform DNS requests on the hostnames, which was not sensible behavior. Fixes bug 10801; bugfix on 0.2.0.1-alpha.
Avoid a 60-second delay in the bootstrapping process when a Tor client with pluggable transports re-reads its configuration at just the wrong time. Re-fixes bug 11156; bugfix on 0.2.5.3-alpha.
Minor bugfixes (client, logging during bootstrap):
Warn only once if we start logging in an unsafe way. Previously, we complain as many times as we had problems. Fixes bug 9870; bugfix on 0.2.5.1-alpha.
Only report the first fatal bootstrap error on a given OR connection. This stops us from telling the controller bogus error messages like "DONE". Fixes bug 10431; bugfix on 0.2.1.1-alpha.
Be more helpful when trying to run sandboxed on Linux without libseccomp. Instead of saying "Sandbox is not implemented on this platform", we now explain that we need to be built with libseccomp. Fixes bug 11543; bugfix on 0.2.5.1-alpha.
Avoid generating spurious warnings when starting with DisableNetwork enabled. Fixes bug 11200 and bug 10405; bugfix on 0.2.3.9-alpha.
Minor bugfixes (closing OR connections):
If write_to_buf() in connection_write_to_buf_impl_() ever fails, check if it's an or_connection_t and correctly call connection_or_close_for_error() rather than connection_mark_for_close() directly. Fixes bug 11304; bugfix on 0.2.4.4-alpha.
When closing all connections on setting DisableNetwork to 1, use connection_or_close_normally() rather than closing OR connections out from under the channel layer. Fixes bug 11306; bugfix on 0.2.4.4-alpha.
Minor bugfixes (controller):
Avoid sending a garbage value to the controller when a circuit is cannibalized. Fixes bug 11519; bugfix on 0.2.3.11-alpha.
Minor bugfixes (tor-fw-helper):
Allow tor-fw-helper to build again by adding src/ext to its CPPFLAGS. Fixes bug 11296; bugfix on 0.2.5.3-alpha.
Minor bugfixes (bridges):
Avoid potential crashes or bad behavior when launching a server-side managed proxy with ORPort or ExtORPort temporarily disabled. Fixes bug 9650; bugfix on 0.2.3.16-alpha.
Minor bugfixes (platform-specific):
Fix compilation on Solaris, which does not have . Fixes bug 11426; bugfix on 0.2.5.3-alpha.
When dumping a malformed directory object to disk, save it in binary mode on Windows, not text mode. Fixes bug 11342; bugfix on 0.2.2.1-alpha.
Don't report failures from make_socket_reuseable() on incoming sockets on OSX: this can happen when incoming connections close early. Fixes bug 10081.
Minor bugfixes (trivial memory leaks):
Fix a small memory leak when signing a directory object. Fixes bug 11275; bugfix on 0.2.4.13-alpha.
Free placeholder entries in our circuit table at exit; fixes a harmless memory leak. Fixes bug 11278; bugfix on 0.2.5.1-alpha.
Don't re-initialize a second set of OpenSSL mutexes when starting up. Previously, we'd make one set of mutexes, and then immediately replace them with another. Fixes bug 11726; bugfix on 0.2.5.3-alpha.
Resolve some memory leaks found by coverity in the unit tests, on exit in tor-gencert, and on a failure to compute digests for our own keys when generating a v3 networkstatus vote. These leaks should never have affected anyone in practice.
Minor bugfixes (hidden service):
Only retry attempts to connect to a chosen rendezvous point 8 times, not 30. Fixes bug 4241; bugfix on 0.1.0.1-rc.
Minor bugfixes (misc code correctness):
Fix various instances of undefined behavior in channeltls.c, tor_memmem(), and eventdns.c that would cause us to construct pointers to memory outside an allocated object. (These invalid pointers were not accessed, but C does not even allow them to exist.) Fixes bug 10363; bugfixes on 0.1.1.1-alpha, 0.1.2.1-alpha, 0.2.0.10-alpha, and 0.2.3.6-alpha. Reported by "bobnomnom".
Use the AddressSanitizer and Ubsan sanitizers (in clang-3.4) to fix some miscellaneous errors in our tests and codebase. Fixes bug 11232. Bugfixes on versions back as far as 0.2.1.11-alpha.
Always check return values for unlink, munmap, UnmapViewOfFile; check strftime return values more often. In some cases all we can do is report a warning, but this may help prevent deeper bugs from going unnoticed. Closes ticket 8787; bugfixes on many, many tor versions.
Fix numerous warnings from the clang "scan-build" static analyzer. Some of these are programming style issues; some of them are false positives that indicated awkward code; some are undefined behavior cases related to constructing (but not using) invalid pointers; some are assumptions about API behavior; some are (harmlessly) logging sizeof(ptr) bytes from a token when sizeof(*ptr) would be correct; and one or two are genuine bugs that weren't reachable from the rest of the program. Fixes bug 8793; bugfixes on many, many tor versions.
Documentation:
Build the torify.1 manpage again. Previously, we were only trying to build it when also building tor-fw-helper. That's why we didn't notice that we'd broken the ability to build it. Fixes bug 11321; bugfix on 0.2.5.1-alpha.
Fix the layout of the SOCKSPort flags in the manpage. Fixes bug 11061; bugfix on 0.2.4.7-alpha.
Correctly document that we search for a system torrc file before looking in ~/.torrc. Fixes documentation side of 9213; bugfix on 0.2.3.18-rc.
Resolve warnings from Doxygen.
Code simplifications and refactoring:
Remove is_internal_IP() function. Resolves ticket 4645.
Remove unused function circuit_dump_by_chan from circuitlist.c. Closes issue 9107; patch from "marek".
Change our use of the ENUM_BF macro to avoid declarations that confuse Doxygen.
Deprecated versions:
Tor 0.2.2.x has reached end-of-life; it has received no patches or attention for some while. Directory authorities no longer accept descriptors from relays running any version of Tor prior to Tor 0.2.3.16-alpha. Resolves ticket 11149.
Testing:
New macros in test.h to simplify writing mock-functions for unit tests. Part of ticket 11507. Patch from Dana Koch.
Complete tests for the status.c module. Resolves ticket 11507. Patch from Dana Koch.
Removed code:
Remove all code for the long unused v1 directory protocol. Resolves ticket 11070.

New in Tor 0.2.5.3 Alpha (Mar 24, 2014)

Tor 0.2.5.3-alpha includes all the fixes from 0.2.4.21. It contains two new anti-DoS features for Tor relays, resolves a bug that kept SOCKS5 support for IPv6 from working, fixes several annoying usability issues for bridge users, and removes more old code for unused directory formats.
The Tor 0.2.5.x release series is now in patch-freeze: no feature patches not already written will be considered for inclusion in 0.2.5.x.
Major features (relay security, DoS-resistance):
When deciding whether we have run out of memory and we need to close circuits, also consider memory allocated in buffers for streams attached to each circuit.
This change, which extends an anti-DoS feature introduced in 0.2.4.13-alpha and improved in 0.2.4.14-alpha, lets Tor exit relays better resist more memory-based DoS attacks than before. Since the MaxMemInCellQueues option now applies to all queues, it is renamed to MaxMemInQueues. This feature fixes bug 10169.
Avoid hash-flooding denial-of-service attacks by using the secure SipHash-2-4 hash function for our hashtables. Without this feature, an attacker could degrade performance of a targeted client or server by flooding their data structures with a large number of entries to be stored at the same hash table position, thereby slowing down the Tor instance. With this feature, hash table positions are derived from a randomized cryptographic key, and an attacker cannot predict which entries will collide. Closes ticket 4900.
Decrease the lower limit of MaxMemInQueues to 256 MBytes (but leave the default at 8GBytes), to better support Raspberry Pi users. Fixes bug 9686; bugfix on 0.2.4.14-alpha.
Minor features (bridges, pluggable transports):
Bridges now write the SHA1 digest of their identity key fingerprint (that is, a hash of a hash of their public key) to notice-level logs, and to a new hashed-fingerprint file. This information will help bridge operators look up their bridge in Globe and similar tools. Resolves ticket 10884.
Improve the message that Tor displays when running as a bridge using pluggable transports without an Extended ORPort listener. Also, log the message in the log file too. Resolves ticket 11043.
Minor features (other):
Add a new option, PredictedPortsRelevanceTime, to control how long after having received a request to connect to a given port Tor will try to keep circuits ready in anticipation of future requests for that port. Patch from "unixninja92"; implements ticket 9176.
Generate a warning if any ports are listed in the SocksPolicy, DirPolicy, AuthDirReject, AuthDirInvalid, AuthDirBadDir, or AuthDirBadExit options. (These options only support address ranges.) Fixes part of ticket 11108.
Update geoip and geoip6 to the February 7 2014 Maxmind GeoLite2 Country database.
Minor bug fixes (new since 0.2.5.2-alpha, also in 0.2.4.21):
Build without warnings under clang 3.4. (We have some macros that define static functions only some of which will get used later in the module. Starting with clang 3.4, these give a warning unless the unused attribute is set on them.) Resolves ticket 10904.
Fix build warnings about missing "a2x" comment when building the manpages from scratch on OpenBSD; OpenBSD calls it "a2x.py". Fixes bug 10929; bugfix on 0.2.2.9-alpha. Patch from Dana Koch.
Minor bug fixes (client):
Improve the log message when we can't connect to a hidden service because all of the hidden service directory nodes hosting its descriptor are excluded. Improves on our fix for bug 10722, which was a bugfix on 0.2.0.10-alpha.
Raise a control port warning when we fail to connect to all of our bridges. Previously, we didn't inform the controller, and the bootstrap process would stall. Fixes bug 11069; bugfix on 0.2.1.2-alpha.
Exit immediately when a process-owning controller exits. Previously, tor relays would wait for a little while after their controller exited, as if they had gotten an INT signal -- but this was problematic, since there was no feedback for the user. To do a clean shutdown, controllers should send an INT signal and give Tor a chance to clean up. Fixes bug 10449; bugfix on 0.2.2.28-beta.
Stop attempting to connect to bridges before our pluggable transports are configured (harmless but resulted in some erroneous log messages). Fixes bug 11156; bugfix on 0.2.3.2-alpha.
Fix connections to IPv6 addresses over SOCKS5. Previously, we were generating incorrect SOCKS5 responses, and confusing client applications. Fixes bug 10987; bugfix on 0.2.4.7-alpha.
Minor bug fixes (relays and bridges):
Avoid crashing on a malformed resolv.conf file when running a relay using Libevent 1. Fixes bug 8788; bugfix on 0.1.1.23.
Non-exit relays no longer launch mock DNS requests to check for DNS hijacking. This has been unnecessary since 0.2.1.7-alpha, when non-exit relays stopped servicing DNS requests. Fixes bug 965; bugfix on 0.2.1.7-alpha. Patch from Matt Pagan.
Bridges now report complete directory request statistics. Related to bug 5824; bugfix on 0.2.2.1-alpha.
Bridges now never collect statistics that were designed for relays. Fixes bug 5824; bugfix on 0.2.3.8-alpha.
Stop giving annoying warning messages when we decide not to launch a pluggable transport proxy that we don't need (because there are no bridges configured to use it). Resolves ticket 5018; bugfix on 0.2.5.2-alpha.
Give the correct URL in the warning message when trying to run a relay on an ancient version of Windows. Fixes bug 9393.
Minor bug fixes (backtrace support):
Support automatic backtraces on more platforms by using the "-fasynchronous-unwind-tables" compiler option. This option is needed for platforms like 32-bit Intel where "-fomit-frame-pointer" is on by default and table generation is not. This doesn't yet add Windows support; only Linux, OSX, and some BSDs are affected. Reported by 'cypherpunks'; fixes bug 11047; bugfix on 0.2.5.2-alpha.
Avoid strange behavior if two threads hit failed assertions at the same time and both try to log backtraces at once. (Previously, if this had happened, both threads would have stored their intermediate results in the same buffer, and generated junk outputs.) Reported by "cypherpunks". Fixes bug 11048; bugfix on 0.2.5.2-alpha.
Fix a compiler warning in format_number_sigsafe(). Bug fix on 0.2.5.2-alpha; patch from Nick Hopper.
Minor bug fixes (unit tests):
Fix a small bug in the unit tests that might have made the tests call 'chmod' with an uninitialized bitmask. Fixes bug 10928; bugfix on 0.2.5.1-alpha. Patch from Dana Koch.
Removed code:
Remove all remaining code related to version-0 hidden service descriptors: they have not been in use since 0.2.2.1-alpha. Fixes the rest of bug 10841.
Documentation:
Document in the manpage that "KBytes" may also be written as "kilobytes" or "KB", that "Kbits" may also be written as "kilobits", and so forth. Closes ticket 9222.
Document that the ClientOnly config option overrides ORPort. Our old explanation made ClientOnly sound as though it did nothing at all. Resolves bug 9059.
Explain that SocksPolicy, DirPolicy, and similar options don't take port arguments. Fixes the other part of ticket 11108.
Fix a comment about the rend_server_descriptor_t.protocols field to more accurately describe its range. Also, make that field unsigned, to more accurately reflect its usage. Fixes bug 9099; bugfix on 0.2.1.5-alpha.
Fix the manpage's description of HiddenServiceAuthorizeClient: the maximum client name length is 16, not 19. Fixes bug 11118; bugfix on 0.2.1.6-alpha.
Code simplifications and refactoring:
Get rid of router->address, since in all cases it was just the string representation of router->addr. Resolves ticket 5528.
Test infrastructure:
Update to the latest version of tinytest.
Improve the tinytest implementation of string operation tests so that comparisons with NULL strings no longer crash the tests; they now just fail, normally. Fixes bug 9004; bug fix on 0.2.2.4-alpha.

New in Tor 0.2.4.21 (Mar 3, 2014)

Tor 0.2.4.21 further improves security against potential adversaries who find breaking 1024-bit crypto doable, and backports several stability and robustness patches from the 0.2.5 branch.
Major features (client security):
When we choose a path for a 3-hop circuit, make sure it contains at least one relay that supports the NTor circuit extension handshake. Otherwise, there is a chance that we're building a circuit that's worth attacking by an adversary who finds breaking 1024-bit crypto doable, and that chance changes the game theory. Implements ticket 9777.
Major bug fixes:
Do not treat streams that fail with reason END_STREAM_REASON_INTERNAL as indicating a definite circuit failure, since it could also indicate an ENETUNREACH connection error. Fixes part of bug 10777; bugfix on 0.2.4.8-alpha.
Code simplification and refactoring:
Remove data structures which were introduced to implement the CellStatistics option: they are now redundant with the new timestamp field in the regular packed_cell_t data structure, which we did in 0.2.4.18-rc in order to resolve bug 9093. Resolves ticket 10870.
Minor features:
Always clear OpenSSL bignums before freeing them -- even bignums that don't contain secrets. Resolves ticket 10793. Patch by Florent Daigniere.
Build without warnings under clang 3.4. (We have some macros that define static functions only some of which will get used later in the module. Starting with clang 3.4, these give a warning unless the unused attribute is set on them.) Resolves ticket 10904.
Update geoip and geoip6 files to the February 7 2014 Maxmind GeoLite2 Country database.
Minor bug fixes:
Set the listen() backlog limit to the largest actually supported on the system, not to the value in a header file. Fixes bug 9716; bugfix on every released Tor.
Treat ENETUNREACH, EACCES, and EPERM connection failures at an exit node as a NOROUTE error, not an INTERNAL error, since they can apparently happen when trying to connect to the wrong sort of netblocks. Fixes part of bug 10777; bugfix on 0.1.0.1-rc.
Fix build warnings about missing "a2x" comment when building the manpages from scratch on OpenBSD; OpenBSD calls it "a2x.py". Fixes bug 10929; bugfix on 0.2.2.9-alpha. Patch from Dana Koch.
Avoid a segfault on SIGUSR1, where we had freed a connection but did not entirely remove it from the connection lists. Fixes bug 9602; bugfix on 0.2.4.4-alpha.
Fix a segmentation fault in our benchmark code when running with Fedora's OpenSSL package, or any other OpenSSL that provides ECDH but not P224. Fixes bug 10835; bugfix on 0.2.4.8-alpha.
Turn "circuit handshake stats since last time" log messages into a heartbeat message. Fixes bug 10485; bugfix on 0.2.4.17-rc.
Documentation fixes:
Document that all but one DirPort entry must have the NoAdvertise flag set. Fixes bug 10470; bugfix on 0.2.3.3-alpha / 0.2.3.16-alpha.

New in Tor 0.2.5.2 Alpha (Feb 14, 2014)

Tor 0.2.5.2-alpha includes all the fixes from 0.2.4.18-rc and 0.2.4.20, like the "poor random number generation" fix and the "building too many circuits" fix. It also further improves security against potential adversaries who find breaking 1024-bit crypto doable, and launches pluggable transports on demand (which gets us closer to integrating pluggable transport support by default -- not to be confused with Tor bundles enabling pluggable transports and bridges by default).
Major features (client security):
When we choose a path for a 3-hop circuit, make sure it contains at least one relay that supports the NTor circuit extension handshake. Otherwise, there is a chance that we're building a circuit that's worth attacking by an adversary who finds breaking 1024-bit crypto doable, and that chance changes the game theory. Implements ticket 9777.
Clients now look at the "usecreatefast" consensus parameter to decide whether to use CREATE_FAST or CREATE cells for the first hop of their circuit. This approach can improve security on connections where Tor's circuit handshake is stronger than the available TLS connection security levels, but the tradeoff is more computational load on guard relays. Implements proposal 221. Resolves ticket 9386.
Major features (bridges):
Don't launch pluggable transport proxies if we don't have any bridges configured that would use them. Now we can list many pluggable transports, and Tor will dynamically start one when it hears a bridge address that needs it. Resolves ticket 5018.
The bridge directory authority now assigns status flags (Stable, Guard, etc) to bridges based on thresholds calculated over all Running bridges. Now bridgedb can finally make use of its features to e.g. include at least one Stable bridge in its answers. Fixes bug 9859.
Major features (other):
Extend ORCONN controller event to include an "ID" parameter, and add four new controller event types CONN_BW, CIRC_BW, CELL_STATS, and TB_EMPTY that show connection and circuit usage. The new events are emitted in private Tor networks only, with the goal of being able to better track performance and load during full-network simulations. Implements proposal 218 and ticket 7359.
On some platforms (currently: recent OSX versions, glibc-based platforms that support the ELF format, and a few other Unix-like operating systems), Tor can now dump stack traces when a crash occurs or an assertion fails. By default, traces are dumped to stderr (if possible) and to any logs that are reporting errors. Implements ticket 9299.
Major bug fixes:
Avoid a segfault on SIGUSR1, where we had freed a connection but did not entirely remove it from the connection lists. Fixes bug 9602; bugfix on 0.2.4.4-alpha.
Do not treat streams that fail with reason END_STREAM_REASON_INTERNAL as indicating a definite circuit failure, since it could also indicate an ENETUNREACH connection error. Fixes part of bug 10777; bugfix on 0.2.4.8-alpha.
Major bug fixes (new since 0.2.5.1-alpha, also in 0.2.4.20):
Do not allow OpenSSL engines to replace the PRNG, even when HardwareAccel is set. The only default builtin PRNG engine uses the Intel RDRAND instruction to replace the entire PRNG, and ignores all attempts to seed it with more entropy. That's cryptographically stupid: the right response to a new alleged entropy source is never to discard all previously used entropy sources. Fixes bug 10402; works around behavior introduced in OpenSSL 1.0.0. Diagnosis and investigation thanks to "coderman" and "rl1987".
Fix assertion failure when AutomapHostsOnResolve yields an IPv6 address. Fixes bug 10465; bugfix on 0.2.4.7-alpha.
Avoid launching spurious extra circuits when a stream is pending. This fixes a bug where any circuit that _wasn't_ unusable for new streams would be treated as if it were, causing extra circuits to be launched. Fixes bug 10456; bugfix on 0.2.4.12-alpha.
Major bug fixes (new since 0.2.5.1-alpha, also in 0.2.4.18-rc):
No longer stop reading or writing on cpuworker connections when our rate limiting buckets go empty. Now we should handle circuit handshake requests more promptly. Resolves bug 9731.
Stop trying to bootstrap all our directory information from only our first guard. Discovered while fixing bug 9946; bugfix on 0.2.4.8-alpha.
Minor features (bridges, pluggable transports):
Add threshold cutoffs to the networkstatus document created by the Bridge Authority. Fixes bug 1117.
On Windows, spawn background processes using the CREATE_NO_WINDOW flag. Now Tor Browser Bundle 3.5 with pluggable transports enabled doesn't pop up a blank console window. (In Tor Browser Bundle 2.x, Vidalia set this option for us.) Implements ticket 10297.
Minor features (security):
Always clear OpenSSL bignums before freeing them -- even bignums that don't contain secrets. Resolves ticket 10793. Patch by Florent Daignière.
Minor features (config options and command line):
Add an --allow-missing-torrc commandline option that tells Tor to run even if the configuration file specified by -f is not available. Implements ticket 10060.
Add support for the TPROXY transparent proxying facility on Linux. See documentation for the new TransProxyType option for more details. Implementation by "thomo". Closes ticket 10582.
Minor features (controller):
Add a new "HS_DESC" controller event that reports activities related to hidden service descriptors. Resolves ticket 8510.
New "DROPGUARDS" controller command to forget all current entry guards. Not recommended for ordinary use, since replacing guards too frequently makes several attacks easier. Resolves ticket 9934; patch from "ra".
Minor features (build):
Assume that a user using ./configure --host wants to cross-compile, and give an error if we cannot find a properly named tool-chain. Add a --disable-tool-name-check option to proceed nevertheless. Addresses ticket 9869. Patch by Benedikt Gollatz.
If we run ./configure and the compiler recognizes -fstack-protector but the linker rejects it, warn the user about a potentially missing libssp package. Addresses ticket 9948. Patch from Benedikt Gollatz.
Minor features (testing):
If Python is installed, "make check" now runs extra tests beyond the unit test scripts.
When bootstrapping a test network, sometimes very few relays get the Guard flag. Now a new option "TestingDirAuthVoteGuard" can specify a set of relays which should be voted Guard regardless of their uptime or bandwidth. Addresses ticket 9206.
Minor features (log messages):
When ServerTransportPlugin is set on a bridge, Tor can write more useful statistics about bridge use in its extrainfo descriptors, but only if the Extended ORPort ("ExtORPort") is set too. Add a log message to inform the user in this case. Resolves ticket 9651.
When receiving a new controller connection, log the origin address. Resolves ticket 9698; patch from "sigpipe".
When logging OpenSSL engine status at startup, log the status of more engines. Fixes ticket 10043; patch from Joshua Datko.
Turn "circuit handshake stats since last time" log messages into a heartbeat message. Fixes bug 10485; bugfix on 0.2.4.17-rc.
Minor features (new since 0.2.5.1-alpha, also in 0.2.4.18-rc):
Improve the circuit queue out-of-memory handler. Previously, when we ran low on memory, we'd close whichever circuits had the most queued cells. Now, we close those that have the *oldest* queued cells, on the theory that those are most responsible for us running low on memory. Based on analysis from a forthcoming paper by Jansen, Tschorsch, Johnson, and Scheuermann. Fixes bug 9093.
Generate bootstrapping status update events correctly when fetching microdescriptors. Fixes bug 9927.
Update to the October 2 2013 Maxmind GeoLite Country database.
Minor bug fixes (clients):
When closing a channel that has already been open, do not close pending circuits that were waiting to connect to the same relay. Fixes bug 9880; bugfix on 0.2.5.1-alpha. Thanks to skruffy for finding this bug.
Minor bug fixes (relays):
Treat ENETUNREACH, EACCES, and EPERM connection failures at an exit node as a NOROUTE error, not an INTERNAL error, since they can apparently happen when trying to connect to the wrong sort of netblocks. Fixes part of bug 10777; bugfix on 0.1.0.1-rc.
Minor bug fixes (bridges):
Fix a bug where the first connection works to a bridge that uses a pluggable transport with client-side parameters, but we don't send the client-side parameters on subsequent connections. (We don't use any pluggable transports with client-side parameters yet, but ScrambleSuit will soon become the first one.) Fixes bug 9162; bugfix on 0.2.0.3-alpha. Based on a patch from "rl1987".
Minor bug fixes (node selection):
If ExcludeNodes is set, consider non-excluded hidden service directory servers before excluded ones. Do not consider excluded hidden service directory servers at all if StrictNodes is set. (Previously, we would sometimes decide to connect to those servers, and then realize before we initiated a connection that we had excluded them.) Fixes bug 10722; bugfix on 0.2.0.10-alpha. Reported by "mr-4".
If we set the ExitNodes option but it doesn't include any nodes that have the Exit flag, we would choose not to bootstrap. Now we bootstrap so long as ExitNodes includes nodes which can exit to some port. Fixes bug 10543; bugfix on 0.2.4.10-alpha.
Minor bug fixes (controller and command-line):
If changing a config option via "setconf" fails in a recoverable way, we used to nonetheless write our new control ports to the file described by the "ControlPortWriteToFile" option. Now we only write out that file if we successfully switch to the new config option. Fixes bug 5605; bugfix on 0.2.2.26-beta. Patch from "Ryman".
When a command-line option such as --version or --help that ordinarily implies --hush appears on the command line along with --quiet, then actually obey --quiet. Previously, we obeyed --quiet only if it appeared later on the command line. Fixes bug 9578; bugfix on 0.2.5.1-alpha.
Minor bug fixes (code correctness):
Previously we used two temporary files when writing descriptors to disk; now we only use one. Fixes bug 1376.
Remove an erroneous (but impossible and thus harmless) pointer comparison that would have allowed compilers to skip a bounds check in channeltls.c. Fixes bugs 10313 and 9980; bugfix on 0.2.0.10-alpha. Noticed by Jared L Wong and David Fifield.
Fix an always-true assertion in pluggable transports code so it actually checks what it was trying to check. Fixes bug 10046; bugfix on 0.2.3.9-alpha. Found by "dcb".
Minor bug fixes (protocol correctness):
When receiving a VERSIONS cell with an odd number of bytes, close the connection immediately since the cell is malformed. Fixes bug 10365; bugfix on 0.2.0.10-alpha. Spotted by "bobnomnom"; fix by "rl1987".
Minor bug fixes (build):
Restore the ability to compile Tor with V2_HANDSHAKE_SERVER turned off (that is, without support for v2 link handshakes). Fixes bug 4677; bugfix on 0.2.3.2-alpha. Patch from "piet".
Fix compilation warnings and startup issues when running with "Sandbox 1" and libseccomp-2.1.0. Fixes bug 10563; bugfix on 0.2.5.1-alpha.
Fix compilation on Solaris 9, which didn't like us having an identifier named "sun". Fixes bug 10565; bugfix in 0.2.5.1-alpha.
Minor bug fixes (testing):
Fix a segmentation fault in our benchmark code when running with Fedora's OpenSSL package, or any other OpenSSL that provides ECDH but not P224. Fixes bug 10835; bugfix on 0.2.4.8-alpha.
Minor bug fixes (log messages):
Fix a bug where clients using bridges would report themselves as 50% bootstrapped even without a live consensus document. Fixes bug 9922; bugfix on 0.2.1.1-alpha.
Suppress a warning where, if there's only one directory authority in the network, we would complain that votes and signatures cannot be uploaded to other directory authorities. Fixes bug 10842; bugfix on 0.2.2.26-beta.
Report bootstrapping progress correctly when we're downloading microdescriptors. We had updated our "do we have enough microdescs to begin building circuits?" logic most recently in 0.2.4.10-alpha (see bug 5956), but we left the bootstrap status event logic at "how far through getting 1/4 of them are we?" Fixes bug 9958; bugfix on 0.2.2.36, which is where they diverged (see bug 5343).
Minor bug fixes (new since 0.2.5.1-alpha, also in 0.2.4.20):
Avoid a crash bug when starting with a corrupted microdescriptor cache file. Fixes bug 10406; bugfix on 0.2.2.6-alpha.
If we fail to dump a previously cached microdescriptor to disk, avoid freeing duplicate data later on. Fixes bug 10423; bugfix on 0.2.4.13-alpha. Spotted by "bobnomnom".
Minor bug fixes on 0.2.4.x (new since 0.2.5.1-alpha, also in 0.2.4.18-rc):
Correctly log long IPv6 exit policies, instead of truncating them or reporting an error. Fixes bug 9596; bugfix on 0.2.4.7-alpha.
Our default TLS ecdhe groups were backwards: we meant to be using P224 for relays (for performance win) and P256 for bridges (since it is more common in the wild). Instead we had it backwards. After reconsideration, we decided that the default should be P256 on all hosts, since its security is probably better, and since P224 is reportedly used quite little in the wild. Found by "skruffy" on IRC. Fix for bug 9780; bugfix on 0.2.4.8-alpha.
Free directory authority certificate download statuses on exit rather than leaking them. Fixes bug 9644; bugfix on 0.2.4.13-alpha.
Minor bug fixes on 0.2.3.x (new since 0.2.5.1-alpha, also in 0.2.4.18-rc):
If the guard we choose first doesn't answer, we would try the second guard, but once we connected to the second guard we would abandon it and retry the first one, slowing down bootstrapping. The fix is to treat all our initially chosen guards as acceptable to use. Fixes bug 9946; bugfix on 0.1.1.11-alpha.
Fix an assertion failure that would occur when disabling the ORPort setting on a running Tor process while accounting was enabled. Fixes bug 6979; bugfix on 0.2.2.18-alpha.
When examining the list of network interfaces to find our address, do not consider non-running or disabled network interfaces. Fixes bug 9904; bugfix on 0.2.3.11-alpha. Patch from "hantwister".
Avoid an off-by-one error when checking buffer boundaries when formatting the exit status of a pluggable transport helper. This is probably not an exploitable bug, but better safe than sorry. Fixes bug 9928; bugfix on 0.2.3.18-rc. Bug found by Pedro Ribeiro.
Removed code and features:
Clients now reject any directory authority certificates lacking a dir-key-crosscert element. These have been included since 0.2.1.9-alpha, so there's no real reason for them to be optional any longer. Completes proposal 157. Resolves ticket 10162.
Remove all code that existed to support the v2 directory system, since there are no longer any v2 directory authorities. Resolves ticket 10758.
Remove the HSAuthoritativeDir and AlternateHSAuthority torrc options, which were used for designating authorities as "Hidden service authorities". There has been no use of hidden service authorities since 0.2.2.1-alpha, when we stopped uploading or downloading v0 hidden service descriptors. Fixes bug 10881; also part of a fix for bug 10841.
Code simplification and refactoring:
Remove some old fallback code designed to keep Tor clients working in a network with only two working relays. Elsewhere in the code we have long since stopped supporting such networks, so there wasn't much point in keeping it around. Addresses ticket 9926.
Reject 0-length EXTEND2 cells more explicitly. Fixes bug 10536; bugfix on 0.2.4.8-alpha. Reported by "cypherpunks".
Remove data structures which were introduced to implement the CellStatistics option: they are now redundant with the addition of a timestamp to the regular packed_cell_t data structure, which we did in 0.2.4.18-rc in order to resolve ticket 9093. Implements ticket 10870.
Documentation (man page) fixes:
Update manpage to describe some of the files you can expect to find in Tor's DataDirectory. Addresses ticket 9839.
Document that all but one DirPort entry must have the NoAdvertise flag set. Fixes bug 10470; bugfix on 0.2.3.3-alpha / 0.2.3.16-alpha.
Documentation fixes (new since 0.2.5.1-alpha, also in 0.2.4.18-rc):
Clarify the usage and risks of setting the ContactInfo torrc line for your relay or bridge. Resolves ticket 9854.
Add anchors to the manpage so we can link to the html version of the documentation for specific options. Resolves ticket 9866.
Replace remaining references to DirServer in man page and log entries. Resolves ticket 10124.
Tool changes:
Make the "tor-gencert" tool used by directory authority operators create 2048-bit signing keys by default (rather than 1024-bit, since 1024-bit is uncomfortably small these days). Addresses ticket 10324.

New in Tor 0.2.4.20 (Dec 23, 2013)

New in Tor 0.2.4.19 (Dec 12, 2013)

New in Tor 0.2.4.18 RC (Nov 18, 2013)

Tor 0.2.4.18-rc is the fourth release candidate for the Tor 0.2.4.x series. It takes a variety of fixes from the 0.2.5.x branch to improve stability, performance, and better handling of edge cases.
Major features:
Re-enable TLS 1.1 and 1.2 when built with OpenSSL 1.0.1e or later. Resolves ticket 6055. (OpenSSL before 1.0.1 didn't have TLS 1.1 or 1.2, and OpenSSL from 1.0.1 through 1.0.1d had bugs that prevented renegotiation from working with TLS 1.1 or 1.2, so we had disabled them to solve bug 6033.)
Major bug fixes:
No longer stop reading or writing on cpuworker connections when our rate limiting buckets go empty. Now we should handle circuit handshake requests more promptly. Resolves bug 9731.
If we are unable to save a microdescriptor to the journal, do not drop it from memory and then reattempt downloading it. Fixes bug 9645; bugfix on 0.2.2.6-alpha.
Stop trying to bootstrap all our directory information from only our first guard. Discovered while fixing bug 9946; bugfix on 0.2.4.8-alpha.
The new channel code sometimes lost track of in-progress circuits, causing long-running clients to stop building new circuits. The fix is to always call circuit_n_chan_done(chan, 0) from channel_closed(). Fixes bug 9776; bugfix on 0.2.4.17-rc.
Minor bug fixes (on 0.2.4.x):
Correctly log long IPv6 exit policies, instead of truncating them or reporting an error. Fixes bug 9596; bugfix on 0.2.4.7-alpha.
Our default TLS ecdhe groups were backwards: we meant to be using P224 for relays (for performance win) and P256 for bridges (since it is more common in the wild). Instead we had it backwards. After reconsideration, we decided that the default should be P256 on all hosts, since its security is probably better, and since P224 is reportedly used quite little in the wild. Found by "skruffy" on IRC. Fix for bug 9780; bugfix on 0.2.4.8-alpha.
Free directory authority certificate download statuses on exit rather than leaking them. Fixes bug 9644; bugfix on 0.2.4.13-alpha.
Minor bug fixes (on 0.2.3.x and earlier):
If the guard we choose first doesn't answer, we would try the second guard, but once we connected to the second guard we would abandon it and retry the first one, slowing down bootstrapping. The fix is to treat all our initially chosen guards as acceptable to use. Fixes bug 9946; bugfix on 0.1.1.11-alpha.
Fix an assertion failure that would occur when disabling the ORPort setting on a running Tor process while accounting was enabled. Fixes bug 6979; bugfix on 0.2.2.18-alpha.
When examining the list of network interfaces to find our address, do not consider non-running or disabled network interfaces. Fixes bug 9904; bugfix on 0.2.3.11-alpha. Patch from "hantwister".
Avoid an off-by-one error when checking buffer boundaries when formatting the exit status of a pluggable transport helper. This is probably not an exploitable bug, but better safe than sorry. Fixes bug 9928; bugfix on 0.2.3.18-rc. Bug found by Pedro Ribeiro.
Minor features (protecting client timestamps):
Clients no longer send timestamps in their NETINFO cells. These were not used for anything, and they provided one small way for clients to be distinguished from each other as they moved from network to network or behind NAT. Implements part of proposal 222.
Clients now round timestamps in INTRODUCE cells down to the nearest 10 minutes. If a new Support022HiddenServices option is set to 0, or if it's set to "auto" and the feature is disabled in the consensus, the timestamp is sent as 0 instead. Implements part of proposal 222.
Stop sending timestamps in AUTHENTICATE cells. This is not such a big deal from a security point of view, but it achieves no actual good purpose, and isn't needed. Implements part of proposal 222.
Reduce down accuracy of timestamps in hidden service descriptors. Implements part of proposal 222.
Minor features (other):
Improve the circuit queue out-of-memory handler. Previously, when we ran low on memory, we'd close whichever circuits had the most queued cells. Now, we close those that have the *oldest* queued cells, on the theory that those are most responsible for us running low on memory. Based on analysis from a forthcoming paper by Jansen, Tschorsch, Johnson, and Scheuermann. Fixes bug 9093.
Generate bootstrapping status update events correctly when fetching microdescriptors. Fixes bug 9927.
Update to the October 2 2013 Maxmind GeoLite Country database.
Documentation fixes:
Clarify the usage and risks of setting the ContactInfo torrc line for your relay or bridge. Resolves ticket 9854.
Add anchors to the manpage so we can link to the html version of the documentation for specific options. Resolves ticket 9866.
Replace remaining references to DirServer in man page and log entries. Resolves ticket 10124.

New in Tor 0.2.5.1 Alpha (Oct 2, 2013)

Tor 0.2.5.1-alpha introduces experimental support for syscall sandboxing on Linux, allows bridges that offer pluggable transports to report usage statistics, fixes many issues to make testing easier, and provides a pile of minor features and bug fixes that have been waiting for a release of the new branch.
This is the first alpha release in a new series, so expect there to be bugs. Users who would rather test out a more stable branch should stay with 0.2.4.x for now.
Major features (security):
Use the seccomp2 syscall filtering facility on Linux to limit which system calls Tor can invoke. This is an experimental, Linux-only feature to provide defense-in-depth against unknown attacks. To try turning it on, set "Sandbox 1" in your torrc file. Please be ready to report bugs. We hope to add support for better sandboxing in the future, including more fine-grained filters, better division of responsibility, and support for more platforms. This work has been done by Cristian-Matei Toader for Google Summer of Code.
Re-enable TLS 1.1 and 1.2 when built with OpenSSL 1.0.1e or later. Resolves ticket 6055. (OpenSSL before 1.0.1 didn't have TLS 1.1 or 1.2, and OpenSSL from 1.0.1 through 1.0.1d had bugs that prevented renegotiation from working with TLS 1.1 or 1.2, so we had disabled them to solve bug 6033.)
Major features (other):
Add support for passing arguments to managed pluggable transport proxies. Implements ticket 3594.
Bridges now track GeoIP information and the number of their users even when pluggable transports are in use, and report usage statistics in their extra-info descriptors. Resolves tickets 4773 and 5040.
Make testing Tor networks bootstrap better: lower directory fetch retry schedules and maximum interval without directory requests, and raise maximum download tries. Implements ticket 6752.
Add make target 'test-network' to run tests on a Chutney network. Implements ticket 8530.
The ntor handshake is now on-by-default, no matter what the directory authorities recommend. Implements ticket 8561.
Major bug fixes:
Instead of writing destroy cells directly to outgoing connection buffers, queue them and intersperse them with other outgoing cells. This can prevent a set of resource starvation conditions where too many pending destroy cells prevent data cells from actually getting delivered. Reported by "oftc_must_be_destroyed". Fixes bug 7912; bugfix on 0.2.0.1-alpha.
If we are unable to save a microdescriptor to the journal, do not drop it from memory and then reattempt downloading it. Fixes bug 9645; bugfix on 0.2.2.6-alpha.
The new channel code sometimes lost track of in-progress circuits, causing long-running clients to stop building new circuits. The fix is to always call circuit_n_chan_done(chan, 0) from channel_closed(). Fixes bug 9776; bugfix on 0.2.4.17-rc.
Build features:
Tor now builds each source file in two modes: a mode that avoids exposing identifiers needlessly, and another mode that exposes more identifiers for testing. This lets the compiler do better at optimizing the production code, while enabling us to take more radical measures to let the unit tests test things.
The production builds no longer include functions used only in the unit tests; all functions exposed from a module only for unit-testing are now static in production builds.
Add an --enable-coverage configuration option to make the unit tests (and a new src/or/tor-cov target) to build with gcov test coverage support.
Testing:
We now have rudimentary function mocking support that our unit tests can use to test functions in isolation. Function mocking lets the tests temporarily replace a function's dependencies with stub functions, so that the tests can check the function without invoking the other functions it calls.
Add more unit tests for the ->circuit map, and the destroy-cell-tracking code to fix bug 7912.
Unit tests for failing cases of the TAP onion handshake.
More unit tests for address-manipulation functions.
Minor features (protecting client timestamps):
Clients no longer send timestamps in their NETINFO cells. These were not used for anything, and they provided one small way for clients to be distinguished from each other as they moved from network to network or behind NAT. Implements part of proposal 222.
Clients now round timestamps in INTRODUCE cells down to the nearest 10 minutes. If a new Support022HiddenServices option is set to 0, or if it's set to "auto" and the feature is disabled in the consensus, the timestamp is sent as 0 instead. Implements part of proposal 222.
Stop sending timestamps in AUTHENTICATE cells. This is not such a big deal from a security point of view, but it achieves no actual good purpose, and isn't needed. Implements part of proposal 222.
Reduce down accuracy of timestamps in hidden service descriptors. Implements part of proposal 222.
Minor features (config options):
Config (torrc) lines now handle fingerprints which are missing their initial '$'. Resolves ticket 4341; improvement over 0.0.9pre5.
Support a --dump-config option to print some or all of the configured options. Mainly useful for debugging the command-line option parsing code. Helps resolve ticket 4647.
Raise awareness of safer logging: notify user of potentially unsafe config options, like logging more verbosely than severity "notice" or setting SafeLogging to 0. Resolves ticket 5584.
Add a new configuration option TestingV3AuthVotingStartOffset that bootstraps a network faster by changing the timing for consensus votes. Addresses ticket 8532.
Add a new torrc option "ServerTransportOptions" that allows bridge operators to pass configuration parameters to their pluggable transports. Resolves ticket 8929.
The config (torrc) file now accepts bandwidth and space limits in bits as well as bytes. (Anywhere that you can say "2 Kilobytes", you can now say "16 kilobits", and so on.) Resolves ticket 9214. Patch by CharlieB.
Minor features (build):
Add support for `--library-versions` flag. Implements ticket 6384.
Return the "unexpected sendme" warnings to a warn severity, but make them rate limited, to help diagnose ticket 8093.
Detect a missing asciidoc, and warn the user about it, during configure rather than at build time. Fixes issue 6506. Patch from Arlo Breault.
Minor features (other):
Use the SOCK_NONBLOCK socket type, if supported, to open nonblocking sockets in a single system call. Implements ticket 5129.
Log current accounting state (bytes sent and received + remaining time for the current accounting period) in the relay's heartbeat message. Implements ticket 5526; patch from Peter Retzlaff.
Implement the TRANSPORT_LAUNCHED control port event that notifies controllers about new launched pluggable transports. Resolves ticket 5609.
If we're using the pure-C 32-bit curve25519_donna implementation of curve25519, build it with the -fomit-frame-pointer option to make it go faster on register-starved hosts. This improves our handshake performance by about 6% on i386 hosts without nacl. Closes ticket 8109.
Update to the September 4 2013 Maxmind GeoLite Country database.
Minor bug fixes:
Set the listen() backlog limit to the largest actually supported on the system, not to the value in a header file. Fixes bug 9716; bugfix on every released Tor.
No longer accept malformed http headers when parsing urls from headers. Now we reply with Bad Request ("400"). Fixes bug 2767; bugfix on 0.0.6pre1.
In munge_extrainfo_into_routerinfo(), check the return value of memchr(). This would have been a serious issue if we ever passed it a non-extrainfo. Fixes bug 8791; bugfix on 0.2.0.6-alpha. Patch from Arlo Breault.
On the chance that somebody manages to build Tor on a platform where time_t is unsigned, correct the way that microdesc_add_to_cache() handles negative time arguments. Fixes bug 8042; bugfix on 0.2.3.1-alpha.
Reject relative control socket paths and emit a warning. Previously, single-component control socket paths would be rejected, but Tor would not log why it could not validate the config. Fixes bug 9258; bugfix on 0.2.3.16-alpha.
Minor bug fixes (command line):
Use a single command-line parser for parsing torrc options on the command line and for finding special command-line options to avoid inconsistent behavior for torrc option arguments that have the same names as command-line options. Fixes bugs 4647 and 9578; bugfix on 0.0.9pre5.
No longer allow 'tor --hash-password' with no arguments. Fixes bug 9573; bugfix on 0.0.9pre5.
Minor fixes (build, auxiliary programs):
Stop preprocessing the "torify" script with autoconf, since it no longer refers to LOCALSTATEDIR. Fixes bug 5505; patch from Guilhem.
The tor-fw-helper program now follows the standard convention and exits with status code "0" on success. Fixes bug 9030; bugfix on 0.2.3.1-alpha. Patch by Arlo Breault.
Corrected ./configure advice for what openssl dev package you should install on Debian. Fixes bug 9207; bugfix on 0.2.0.1-alpha.
Minor code improvements:
Remove constants and tests for PKCS1 padding; it's insecure and shouldn't be used for anything new. Fixes bug 8792; patch from Arlo Breault.
Remove instances of strcpy() from the unit tests. They weren't hurting anything, since they were only in the unit tests, but it's embarassing to have strcpy() in the code at all, and some analysis tools don't like it. Fixes bug 8790; bugfix on 0.2.3.6-alpha and 0.2.3.8-alpha. Patch from Arlo Breault.
Removed features:
Remove migration code from when we renamed the "cached-routers" file to "cached-descriptors" back in 0.2.0.8-alpha. This incidentally resolves ticket 6502 by cleaning up the related code a bit. Patch from Akshay Hebbar.
Code simplification and refactoring:
Extract the common duplicated code for creating a subdirectory of the data directory and writing to a file in it. Fixes ticket 4282; patch from Peter Retzlaff.
Since OpenSSL 0.9.7, the i2d_*() functions support allocating output buffer. Avoid calling twice: i2d_RSAPublicKey(), i2d_DHparams(), i2d_X509(), and i2d_PublicKey(). Resolves ticket 5170.
Add a set of accessor functions for the circuit timeout data structure. Fixes ticket 6153; patch from "piet".
Clean up exit paths from connection_listener_new(). Closes ticket 8789. Patch from Arlo Breault.
Since we rely on OpenSSL 0.9.8 now, we can use EVP_PKEY_cmp() and drop our own custom pkey_eq() implementation. Fixes bug 9043.
Use a doubly-linked list to implement the global circuit list. Resolves ticket 9108. Patch from Marek Majkowski.
Remove contrib/id_to_fp.c since it wasn't used anywhere.

New in Tor 0.2.4.17 RC (Sep 5, 2013)

Tor 0.2.4.17-rc is the third release candidate for the Tor 0.2.4.x series. It adds an emergency step to help us tolerate the massive influx of users: 0.2.4 clients using the new (faster and safer) "NTor" circuit-level handshakes now effectively jump the queue compared to the 0.2.3 clients using "TAP" handshakes. This release also fixes a big bug hindering bridge reachability tests.
Major features:
Relays now process the new "NTor" circuit-level handshake requests with higher priority than the old "TAP" circuit-level handshake requests. We still process some TAP requests to not totally starve 0.2.3 clients when NTor becomes popular. A new consensus parameter "NumNTorsPerTAP" lets us tune the balance later if we need to. Implements ticket 9574.
Major bug fixes:
If the circuit build timeout logic is disabled (via the consensus, or because we are an authority), then don't build testing circuits. Fixes bug 9657; bugfix on 0.2.2.14-alpha.
Bridges now send AUTH_CHALLENGE cells during their v3 handshakes; previously they did not, which prevented them from receiving successful connections from relays for self-test or bandwidth testing. Also, when a relay is extending a circuit to a bridge, it needs to send a NETINFO cell, even when the bridge hasn't sent an AUTH_CHALLENGE cell. Fixes bug 9546; bugfix on 0.2.3.6-alpha.
If the time to download the next old-style networkstatus is in the future, do not decline to consider whether to download the next microdescriptor networkstatus. Fixes bug 9564; bugfix on 0.2.3.14-alpha.
Minor bug fixes:
Avoid double-closing the listener socket in our socketpair() replacement (used on Windows) in the case where the addresses on our opened sockets don't match what we expected. Fixes bug 9400; bugfix on 0.0.2pre7. Found by Coverity.
Minor fixes (config options):
Avoid overflows when the user sets MaxCircuitDirtiness to a ridiculously high value, by imposing a (ridiculously high) 30-day maximum on MaxCircuitDirtiness.
Fix the documentation of HeartbeatPeriod to say that the heartbeat message is logged at notice, not at info.
Warn and fail if a server is configured not to advertise any ORPorts at all. (We need *something* to put in our descriptor, or we just won't work.)
Minor features:
Track how many "TAP" and "NTor" circuit handshake requests we get, and how many we complete, and log it every hour to help relay operators follow trends in network load. Addresses ticket 9658.
Update to the August 7 2013 Maxmind GeoLite Country database.

New in Tor 0.2.4.16 RC (Aug 12, 2013)

New in Tor 0.2.4.15 RC (Jul 4, 2013)

New in Tor 0.2.4.14 Alpha (Jun 19, 2013)

New in Tor 0.2.4.13 Alpha (Jun 15, 2013)

Tor 0.2.4.13-alpha fixes a variety of potential remote crash vulnerabilities, makes socks5 username/password circuit isolation actually actually work (this time for sure!), and cleans up a bunch of other issues in preparation for a release candidate.
Major bug fixes (robustness):
Close any circuit that has too many cells queued on it. Fixes bug 9063; bug fix on the 54th commit of Tor. This bug is a further fix beyond bug 6252, whose fix was merged into 0.2.3.21-rc.
Prevent the get_freelists() function from running off the end of the list of freelists if it somehow gets an unrecognized allocation. Fixes bug 8844; bug fix on 0.2.0.16-alpha. Reported by eugenis.
Avoid an assertion failure on OpenBSD (and perhaps other BSDs) when an exit connection with optimistic data succeeds immediately rather than returning EINPROGRESS. Fixes bug 9017; bug fix on 0.2.3.1-alpha.
Fix a directory authority crash bug when building a consensus using an older consensus as its basis. Fixes bug 8833. Bug fix on 0.2.4.12-alpha.
Major bug fixes:
Avoid a memory leak where we would leak a consensus body when we find that a consensus which we couldn't previously verify due to missing certificates is now verifiable. Fixes bug 8719; bug fix on 0.2.0.10-alpha.
We used to always request authority certificates by identity digest, meaning we'd get the newest one even when we wanted one with a different signing key. Then we would complain about being given a certificate we already had, and never get the one we really wanted. Now we use the "fp-sk/" resource as well as the "fp/" resource to request the one we want. Fixes bug 5595; bug fix on 0.2.0.8-alpha.
Follow the socks5 protocol when offering username/password authentication. The fix for bug 8117 exposed this bug, and it turns out real-world applications like Pidgin do care. Bugfix on 0.2.3.2-alpha; fixes bug 8879.
Prevent failures on Windows Vista and later when rebuilding the microdescriptor cache. Diagnosed by Robert Ransom. Fixes bug 8822; bug fix on 0.2.4.12-alpha.
Minor bug fixes:
Fix an impossible buffer overrun in the AES unit tests. Fixes bug 8845; bug fix on 0.2.0.7-alpha. Found by eugenis.
If for some reason we fail to write a microdescriptor while rebuilding the cache, do not let the annotations from that microdescriptor linger in the cache file, and do not let the microdescriptor stay recorded as present in its old location. Fixes bug 9047; bug fix on 0.2.2.6-alpha.
Fix a memory leak that would occur whenever a configuration option changed. Fixes bug 8718; bug fix on 0.2.3.3-alpha.
Paste the description for PathBias parameters from the man page into or.h, so the code documents them too. Fixes bug 7982; bug fix on 0.2.3.17-beta and 0.2.4.8-alpha.
Relays now treat a changed IPv6 ORPort as sufficient reason to publish an updated descriptor. Fixes bug 6026; bug fix on 0.2.4.1-alpha.
When launching a resolve request on behalf of an AF_UNIX control socket, omit the address field of the new entry connection, used in subsequent controller events, rather than letting tor_dup_addr() set it to "". Fixes bug 8639; bug fix on 0.2.4.12-alpha.
Minor bug fixes (log messages):
Fix a scaling issue in the path bias accounting code that resulted in "Bug:" log messages from either pathbias_scale_close_rates() or pathbias_count_build_success(). This represents a bug fix on a previous bug fix: the original fix attempted in 0.2.4.10-alpha was incomplete. Fixes bug 8235; bug fix on 0.2.4.1-alpha.
Give a less useless error message when the user asks for an IPv4 address on an IPv6-only port, or vice versa. Fixes bug 8846; bug fix on 0.2.4.7-alpha.
Minor features:
Downgrade "unexpected SENDME" warnings to protocol-warn for 0.2.4.x, to tolerate bug 8093 for now.
Add an "ignoring-advertised-bws" boolean to the flag-threshold lines in directory authority votes to describe whether they have enough measured bandwidths to ignore advertised (relay descriptor) bandwidth claims. Resolves ticket 8711.
Update to the June 5 2013 Maxmind GeoLite Country database.
Removed documentation:
Remove some of the older contents of doc/ as obsolete; move others to torspec.git. Fixes bug 8965.
Code simplification and refactoring:
Avoid using character buffers when constructing most directory objects: this approach was unwieldy and error-prone. Instead, build smartlists of strings, and concatenate them when done.

New in Tor 0.2.4.12 Alpha (Apr 18, 2013)

Tor 0.2.4.12-alpha moves Tor forward on several fronts: it starts the process for lengthening the guard rotation period, makes directory authority opinions in the consensus a bit less gameable, makes socks5 username/password circuit isolation actually work, and fixes a wide variety of other issues.
Major features:
Raise the default time that a client keeps an entry guard from "1-2 months" to "2-3 months", as suggested by Tariq Elahi's WPES 2012 paper. (We would make it even longer, but we need better client load balancing first.) Also, make the guard lifetime controllable via a new GuardLifetime torrc option and a GuardLifetime consensus parameter. Start of a fix for bug 8240; bug fix on 0.1.1.11-alpha.
Directory authorities now prefer using measured bandwidths to advertised ones when computing flags and thresholds. Resolves ticket 8273.
Directory authorities that have more than a threshold number of relays with measured bandwidths now treat relays with unmeasured bandwidths as having bandwidth 0. Resolves ticket 8435.
Major bug fixes (assert / resource use):
Avoid a bug where our response to TLS renegotiation under certain network conditions could lead to a busy-loop, with 100% CPU consumption. Fixes bug 5650; bug fix on 0.2.0.16-alpha.
Avoid an assertion when we discover that we'd like to write a cell onto a closing connection: just discard the cell. Fixes another case of bug 7350; bug fix on 0.2.4.4-alpha.
Major bug fixes (client-side privacy):
When we mark a circuit as unusable for new circuits, have it continue to be unusable for new circuits even if MaxCircuitDirtiness is increased too much at the wrong time, or the system clock jumps backwards. Fixes bug 6174; bug fix on 0.0.2pre26.
If ClientDNSRejectInternalAddresses ("do not believe DNS queries which have resolved to internal addresses") is set, apply that rule to IPv6 as well. Fixes bug 8475; bug fix on 0.2.0.7-alpha.
When an exit relay rejects a stream with reason "exit policy", but we only know an exit policy summary (e.g. from the microdesc consensus) for it, do not mark the relay as useless for all exiting. Instead, mark just the circuit as unsuitable for that particular address. Fixes part of bug 7582; bug fix on 0.2.3.2-alpha.
Allow applications to get proper stream isolation with IsolateSOCKSAuth. Many SOCKS5 clients that want to offer username/password authentication also offer "no authentication". Tor had previously preferred "no authentication", so the applications never actually sent Tor their auth details. Now Tor selects username/password authentication if it's offered. You can disable this behavior on a per-SOCKSPort basis via PreferSOCKSNoAuth. Fixes bug 8117; bug fix on 0.2.3.3-alpha.
Major bug fixes (other):
When unable to find any working directory nodes to use as a directory guard, give up rather than adding the same non-working nodes to the directory guard list over and over. Fixes bug 8231; bug fix on 0.2.4.8-alpha.
Minor features:
Reject as invalid most directory objects containing a NUL. Belt-and-suspender fix for bug 8037.
In our testsuite, create temporary directories with a bit more entropy in their name to make name collisions less likely. Fixes bug 8638.
Add CACHED keyword to ADDRMAP events in the control protocol to indicate whether a DNS result will be cached or not. Resolves ticket 8596.
Update to the April 3 2013 Maxmind GeoLite Country database.
Minor features (build):
Detect and reject attempts to build Tor with threading support when OpenSSL has been compiled without threading support. Fixes bug 6673.
Clarify that when autoconf is checking for nacl, it is checking specifically for nacl with a fast curve25519 implementation. Fixes bug 8014.
Warn if building on a platform with an unsigned time_t: there are too many places where Tor currently assumes that time_t can hold negative values. We'd like to fix them all, but probably some will remain.
Minor bug fixes (build):
Fix some bugs in tor-fw-helper-natpmp when trying to build and run it on Windows. More bugs likely remain. Patch from Gisle Vanem. Fixes bug 7280; bug fix on 0.2.3.1-alpha.
Add the old src/or/micro-revision.i filename to CLEANFILES. On the off chance that somebody has one, it will go away as soon as they run "make clean". Fix for bug 7143; bug fix on 0.2.4.1-alpha.
Build Tor correctly on 32-bit platforms where the compiler can build but not run code using the "uint128_t" construction. Fixes bug 8587; bug fix on 0.2.4.8-alpha.
Fix compilation warning with some versions of clang that would prefer the -Wswitch-enum compiler flag to warn about switch statements with missing enum values, even if those switch statements have a "default:" statement. Fixes bug 8598; bug fix on 0.2.4.10-alpha.
Minor bug fixes (protocol):
Fix the handling of a TRUNCATE cell when it arrives while the circuit extension is in progress. Fixes bug 7947; bug fix on 0.0.7.1.
Fix a misframing issue when reading the version numbers in a VERSIONS cell. Previously we would recognize [00 01 00 02] as 'version 1, version 2, and version 0x100', when it should have only included versions 1 and 2. Fixes bug 8059; bug fix on 0.2.0.10-alpha. Reported pseudonymously.
Make the format and order of STREAM events for DNS lookups consistent among the various ways to launch DNS lookups. Fixes bug 8203; bug fix on 0.2.0.24-rc. Patch by "Desoxy."
Correct our check for which versions of Tor support the EXTEND2 cell. We had been willing to send it to Tor 0.2.4.7-alpha and later, when support was really added in version 0.2.4.8-alpha. Fixes bug 8464; bug fix on 0.2.4.8-alpha.
Minor bug fixes (other):
Correctly store microdescriptors and extrainfo descriptors with an internal NUL byte. Fixes bug 8037; bug fix on 0.2.0.1-alpha. Bug reported by "cypherpunks".
Increase the width of the field used to remember a connection's link protocol version to two bytes. Harmless for now, since the only currently recognized versions are one byte long. Reported pseudonymously. Fixes bug 8062; bug fix on 0.2.0.10-alpha.
If the state file's path bias counts are invalid (presumably from a buggy Tor prior to 0.2.4.10-alpha), make them correct. Also add additional checks and log messages to the scaling of Path Bias counts, in case there still are remaining issues with scaling. Should help resolve bug 8235.
Eliminate several instances where we use "Nickname=ID" to refer to nodes in logs. Use "Nickname (ID)" instead. (Elsewhere, we still use "$ID=Nickname", which is also acceptable.) Fixes bug 7065. Bugfix on 0.2.3.21-rc, 0.2.4.5-alpha, 0.2.4.8-alpha, and 0.2.4.10-alpha.
Minor bug fixes (syscalls):
Always check the return values of functions fcntl() and setsockopt(). We don't believe these are ever actually failing in practice, but better safe than sorry. Also, checking these return values should please analysis tools like Coverity. Patch from 'flupzor'. Fixes bug 8206; bug fix on all versions of Tor.
Use direct writes rather than stdio when building microdescriptor caches, in an attempt to mitigate bug 8031, or at least make it less common.
Minor bug fixes (config):
When rejecting a configuration because we were unable to parse a quoted string, log an actual error message. Fixes bug 7950; bug fix on 0.2.0.16-alpha.
Behave correctly when the user disables LearnCircuitBuildTimeout but doesn't tell us what they would like the timeout to be. Fixes bug 6304; bug fix on 0.2.2.14-alpha.
When autodetecting the number of CPUs, use the number of available CPUs in preference to the number of configured CPUs. Inform the user if this reduces the number of available CPUs. Fixes bug 8002; bug fix on 0.2.3.1-alpha.
Make it an error when you set EntryNodes but disable UseGuardNodes, since it will (surprisingly to some users) ignore EntryNodes. Fixes bug 8180; bug fix on 0.2.3.11-alpha.
Allow TestingTorNetworks to override the 4096-byte minimum for the Fast threshold. Otherwise they can't bootstrap until they've observed more traffic. Fixes bug 8508; bug fix on 0.2.4.10-alpha.
Fix some logic errors when the user manually overrides the PathsNeededToBuildCircuits option in torrc. Fixes bug 8599; bug fix on 0.2.4.10-alpha.
Minor bug fixes (log messages to help diagnose bugs):
If we fail to free a microdescriptor because of bug 7164, log the filename and line number from which we tried to free it.
Add another diagnostic to the heartbeat message: track and log overhead that TLS is adding to the data we write. If this is high, we are sending too little data to SSL_write at a time. Diagnostic for bug 7707.
Add more detail to a log message about relaxed timeouts, to help track bug 7799.
Warn more aggressively when flushing microdescriptors to a microdescriptor cache fails, in an attempt to mitigate bug 8031, or at least make it more diagnosable.
Improve debugging output to help track down bug 8185 ("Bug: outgoing relay cell has n_chan==NULL. Dropping.")
Log the purpose of a path-bias testing circuit correctly. Improves a log message from bug 8477; bug fix on 0.2.4.8-alpha.
Minor bug fixes (0.2.4.x log messages that were too noisy):
Don't attempt to relax the timeout of already opened 1-hop circuits. They might never timeout. This should eliminate some/all cases of the relaxed timeout log message.
Use circuit creation time for network liveness evaluation. This should eliminate warning log messages about liveness caused by changes in timeout evaluation. Fixes bug 6572; bug fix on 0.2.4.8-alpha.
Reduce a path bias length check from notice to info. The message is triggered when creating controller circuits. Fixes bug 8196; bug fix on 0.2.4.8-alpha.
Fix a path state issue that triggered a notice during relay startup. Fixes bug 8320; bug fix on 0.2.4.10-alpha.
Reduce occurrences of warns about circuit purpose in connection_ap_expire_building(). Fixes bug 8477; bug fix on 0.2.4.11-alpha.
Minor bug fixes (pre-0.2.4.x log messages that were too noisy):
If we encounter a write failure on a SOCKS connection before we finish our SOCKS handshake, don't warn that we closed the connection before we could send a SOCKS reply. Fixes bug 8427; bug fix on 0.1.0.1-rc.
Correctly recognize that [::1] is a loopback address. Fixes bug 8377; bug fix on 0.2.1.3-alpha.
Fix a directory authority warn caused when we have a large amount of badexit bandwidth. Fixes bug 8419; bug fix on 0.2.2.10-alpha.
Don't log inappropriate heartbeat messages when hibernating: a hibernating node is _expected_ to drop out of the consensus, decide it isn't bootstrapped, and so forth. Fixes bug 7302; bug fix on 0.2.3.1-alpha.
Don't complain about bootstrapping problems while hibernating. These complaints reflect a general code problem, but not one with any problematic effects (no connections are actually opened). Fixes part of bug 7302; bug fix on 0.2.3.2-alpha.
Documentation fixes:
Update tor-fw-helper.1.txt and tor-fw-helper.c to make option names match. Fixes bug 7768.
Make the torify manpage no longer refer to tsocks; torify hasn't supported tsocks since 0.2.3.14-alpha.
Make the tor manpage no longer reference tsocks.
Fix the GeoIPExcludeUnknown documentation to refer to ExcludeExitNodes rather than the currently nonexistent ExcludeEntryNodes. Spotted by "hamahangi" on tor-talk.
Removed files:
The tor-tsocks.conf is no longer distributed or installed. We recommend that tsocks users use torsocks instead. Resolves ticket 8290.

New in Tor 0.2.4.11 Alpha (Mar 12, 2013)

Tor 0.2.4.11-alpha makes relay measurement by directory authorities more robust, makes hidden service authentication work again, and resolves a DPI fingerprint for Tor's SSL transport.
Major features (directory authorities):
Directory authorities now support a new consensus method (17) where they cap the published bandwidth of servers for which insufficient bandwidth measurements exist. Fixes part of bug 2286.
Directory authorities that set "DisableV2DirectoryInfo_ 1" no longer serve any v2 directory information. Now we can test disabling the old deprecated v2 directory format, and see whether doing so has any effect on network load. Begins to fix bug 6783.
Directory authorities now include inside each vote a statement of the performance thresholds they used when assigning flags. Implements ticket 8151.
Major bug fixes (directory authorities):
Stop marking every relay as having been down for one hour every time we restart a directory authority. These artificial downtimes were messing with our Stable and Guard flag calculations. Fixes bug 8218 (introduced by the fix for 1035). Bugfix on 0.2.2.23-alpha.
Major bug fixes (hidden services):
Allow hidden service authentication to succeed again. When we refactored the hidden service introduction code back in 0.2.4.1-alpha, we didn't update the code that checks whether authentication information is present, causing all authentication checks to return "false". Fix for bug 8207; bugfix on 0.2.4.1-alpha. Found by Coverity; this is CID 718615.
Minor features (relays, bridges):
Make bridge relays check once a minute for whether their IP address has changed, rather than only every 15 minutes. Resolves bugs 1913 and 1992.
Refactor resolve_my_address() so it returns the method by which we decided our public IP address (explicitly configured, resolved from explicit hostname, guessed from interfaces, learned by gethostname). Now we can provide more helpful log messages when a relay guesses its IP address incorrectly (e.g. due to unexpected lines in /etc/hosts). Resolves ticket 2267.
Teach bridge-using clients to avoid 0.2.2 bridges when making microdescriptor-related dir requests, and only fall back to normal descriptors if none of their bridges can handle microdescriptors (as opposed to the fix in ticket 4013, which caused them to fall back to normal descriptors if *any* of their bridges preferred them). Resolves ticket 4994.
Randomize the lifetime of our SSL link certificate, so censors can't use the static value for filtering Tor flows. Resolves ticket 8443; related to ticket 4014 which was included in 0.2.2.33.
Minor features (portability):
Tweak the curve25519-donna*.c implementations to tolerate systems that lack stdint.h. Fixes bug 3894; bugfix on 0.2.4.8-alpha.
Use Ville Laurikari's implementation of AX_CHECK_SIGN() to determine the signs of types during autoconf. This is better than our old approach, which didn't work when cross-compiling.
Detect the sign of enum values, rather than assuming that MSC is the only compiler where enum types are all signed. Fixes bug 7727; bugfix on 0.2.4.10-alpha.
Minor features (other):
Say "KBytes" rather than "KB" in the man page (for various values of K), to further reduce confusion about whether Tor counts in units of memory or fractions of units of memory. Resolves ticket 7054.
Clear the high bit on curve25519 public keys before passing them to our backend, in case we ever wind up using a backend that doesn't do so itself. If we used such a backend, and *didn't* clear the high bit, we could wind up in a situation where users with such backends would be distinguishable from users without. Fixes bug 8121; bugfix on 0.2.4.8-alpha.
Update to the March 6 2013 Maxmind GeoLite Country database.
Minor bug fixes (clients):
When we receive a RELAY_END cell with the reason DONE, or with no reason, before receiving a RELAY_CONNECTED cell, report the SOCKS status as "connection refused". Previously we reported these cases as success but then immediately closed the connection. Fixes bug 7902; bugfix on 0.1.0.1-rc. Reported by "oftc_must_be_destroyed".
Downgrade an assertion in connection_ap_expire_beginning to an LD_BUG message. The fix for bug 8024 should prevent this message from displaying, but just in case, a warn that we can diagnose is better than more assert crashes. Fixes bug 8065; bugfix on 0.2.4.8-alpha.
Lower path use bias thresholds to .80 for notice and .60 for warn. Also make the rate limiting flags for the path use bias log messages independent from the original path bias flags. Fixes bug 8161; bugfix on 0.2.4.10-alpha.
Minor bug fixes (relays):
Stop trying to resolve our hostname so often (e.g. every time we think about doing a directory fetch). Now we reuse the cached answer in some cases. Fixes bugs 1992 (bugfix on 0.2.0.20-rc) and 2410 (bugfix on 0.1.2.2-alpha).
Stop sending a stray "(null)" in some cases for the server status "EXTERNAL_ADDRESS" controller event. Resolves bug 8200; bugfix on 0.1.2.6-alpha.
When choosing which stream on a formerly stalled circuit to wake first, make better use of the platform's weak RNG. Previously, we had been using the % ("modulo") operator to try to generate a 1/N chance of picking each stream, but this behaves badly with many platforms' choice of weak RNG. Fixes bug 7801; bugfix on 0.2.2.20-alpha.
Use our own weak RNG when we need a weak RNG. Windows's rand() and Irix's random() only return 15 bits; Solaris's random() returns more bits but its RAND_MAX says it only returns 15, and so on. Motivated by the fix for bug 7801; bugfix on 0.2.2.20-alpha.
Minor bug fixes (directory authorities):
Directory authorities now use less space when formatting identical microdescriptor lines in directory votes. Fixes bug 8158; bugfix on 0.2.4.1-alpha.
Minor bug fixes (memory leaks spotted by Coverity -- bug 7816):
Avoid leaking memory if we fail to compute a consensus signature or we generate a consensus we can't parse. Bugfix on 0.2.0.5-alpha.
Fix a memory leak when receiving headers from an HTTPS proxy. Bugfix on 0.2.1.1-alpha.
Fix a memory leak during safe-cookie controller authentication. Bugfix on 0.2.3.13-alpha.
Avoid memory leak of IPv6 policy content if we fail to format it into a router descriptor. Bugfix on 0.2.4.7-alpha.
Minor bug fixes (other code correctness issues):
Avoid a crash if we fail to generate an extrainfo descriptor. Fixes bug 8208; bugfix on 0.2.3.16-alpha. Found by Coverity; this is CID 718634.
When detecting the largest possible file descriptor (in order to close all file descriptors when launching a new program), actually use _SC_OPEN_MAX. The old code for doing this was very, very broken. Fixes bug 8209; bugfix on 0.2.3.1-alpha. Found by Coverity; this is CID 743383.
Fix a copy-and-paste error when adding a missing A1 to a routerset because of GeoIPExcludeUnknown. Fix for Coverity CID 980650. Bugfix on 0.2.4.10-alpha.
Fix an impossible-to-trigger integer overflow when estimating how long our onionskin queue would take. (This overflow would require us to accept 4 million onionskins before processing 100 of them.) Fixes bug 8210; bugfix on 0.2.4.10-alpha.
Code simplification and refactoring:
Add a wrapper function for the common "log a message with a rate-limit" case.

New in Tor 0.2.4.10 Alpha (Feb 5, 2013)

Tor 0.2.4.10-alpha adds defenses at the directory authority level from certain attacks that flood the network with relays; changes the queue for circuit create requests from a sized-based limit to a time-based limit; resumes building with MSVC on Windows; and fixes a wide variety of other issues.
Major bug fixes (directory authority):
When computing directory thresholds, ignore any rejected-as-sybil nodes during the computation so that they can't influence Fast, Guard, etc. (We shoud have done this for proposal 109.) Fixes bug 8146.
When marking a node as a likely sybil, reset its uptime metrics to zero, so that it cannot time towards getting marked as Guard, Stable, or HSDir. (We shoud have done this for proposal 109.) Fixes bug 8147.
Major bug fixes:
When a TLS write is partially successful but incomplete, remember that the flushed part has been flushed, and notice that bytes were actually written. Reported and fixed pseudonymously. Fixes bug 7708; bugfix on Tor 0.1.0.5-rc.
Reject bogus create and relay cells with 0 circuit ID or 0 stream ID: these could be used to create unexpected streams and circuits which would count as "present" to some parts of Tor but "absent" to others, leading to zombie circuits and streams or to a bandwidth denial-of-service. Fixes bug 7889; bugfix on every released version of Tor. Reported by "oftc_must_be_destroyed".
Rename all macros in our local copy of queue.h to begin with "TOR_". This change seems the only good way to permanently prevent conflicts with queue.h on various operating systems. Fixes bug 8107; bugfix on 0.2.4.6-alpha.
Major features (relay):
Instead of limiting the number of queued onionskins (aka circuit create requests) to a fixed, hard-to-configure number, we limit the size of the queue based on how many we expect to be able to process in a given amount of time. We estimate the time it will take to process an onionskin based on average processing time of previous onionskins. Closes ticket 7291. You'll never have to configure MaxOnionsPending again.
Major features (portability):
Resume building correctly with MSVC and Makefile.nmake. This patch resolves numerous bugs and fixes reported by ultramage, including 7305, 7308, 7309, 7310, 7312, 7313, 7315, 7316, and 7669.
Make the ntor and curve25519 code build correctly with MSVC. Fix on 0.2.4.8-alpha.
Minor features:
When directory authorities are computing thresholds for flags, never let the threshold for the Fast flag fall below 4096 bytes. Also, do not consider nodes with extremely low bandwidths when deciding thresholds for various directory flags. This change should raise our threshold for Fast relays, possibly in turn improving overall network performance; see ticket 1854. Resolves ticket 8145.
The Tor client now ignores sub-domain components of a .onion address. This change makes HTTP "virtual" hosting possible: http://foo.aaaaaaaaaaaaaaaa.onion/ and http://bar.aaaaaaaaaaaaaaaa.onion/ can be two different websites hosted on the same hidden service. Implements proposal 204.
We compute the overhead from passing onionskins back and forth to cpuworkers, and report it when dumping statistics in response to SIGUSR1. Supports ticket 7291.
Minor features (path selection):
When deciding whether we have enough descriptors to build circuits, instead of looking at raw relay counts, look at which fraction of (bandwidth-weighted) paths we're able to build. This approach keeps clients from building circuits if their paths are likely to stand out statistically. The default fraction of paths needed is taken from the consensus directory; you can override it with the new PathsNeededToBuildCircuits option. Fixes ticket 5956.
When any country code is listed in ExcludeNodes or ExcludeExitNodes, and we have GeoIP information, also exclude all nodes with unknown countries "??" and "A1". This behavior is controlled by the new GeoIPExcludeUnknown option: you can make such nodes always excluded with "GeoIPExcludeUnknown 1", and disable the feature with "GeoIPExcludeUnknown 0". Setting "GeoIPExcludeUnknown auto" gets you the default behavior. Implements feature 7706.
Path Use Bias: Perform separate accounting for successful circuit use. Keep separate statistics on stream attempt rates versus stream success rates for each guard. Provide configurable thresholds to determine when to emit log messages or disable use of guards that fail too many stream attempts. Resolves ticket 7802.
Minor features (log messages):
When learning a fingerprint for a bridge, log its corresponding transport type. Implements ticket 7896.
Improve the log message when "Bug/attack: unexpected sendme cell from client" occurs, to help us track bug 8093.
Minor bug fixes:
Remove a couple of extraneous semicolons that were upsetting the cparser library. Patch by Christian Grothoff. Fixes bug 7115; bugfix on 0.2.2.1-alpha.
Remove a source of rounding error during path bias count scaling; don't count cannibalized circuits as used for path bias until we actually try to use them; and fix a circuit_package_relay_cell() warning message about n_chan==NULL. Fixes bug 7802.
Detect nacl when its headers are in a nacl/ subdirectory. Also, actually link against nacl when we're configured to use it. Fixes bug 7972; bugfix on 0.2.4.8-alpha.
Compile correctly with the --disable-curve25519 option. Fixes bug 8153; bugfix on 0.2.4.8-alpha.
Build improvements:
Do not report status verbosely from autogen.sh unless the -v flag is specified. Fixes issue 4664. Patch from Onizuka.
Replace all calls to snprintf() outside of src/ext with tor_snprintf(). Also remove the #define to replace snprintf with _snprintf on Windows; they have different semantics, and all of our callers should be using tor_snprintf() anyway. Fixes bug 7304.
Try to detect if we are ever building on a platform where memset(...,0,...) does not set the value of a double to 0.0. Such platforms are permitted by the C standard, though in practice they're pretty rare (since IEEE 754 is nigh-ubiquitous). We don't currently support them, but it's better to detect them and fail than to perform erroneously.
Removed features:
Stop exporting estimates of v2 and v3 directory traffic shares in extrainfo documents. They were unneeded and sometimes inaccurate. Also stop exporting any v2 directory request statistics. Resolves ticket 5823.
Drop support for detecting and warning about versions of Libevent before 1.3e. Nothing reasonable ships with them any longer; warning the user about them shouldn't be needed. Resolves ticket 6826.
Code simplifications and refactoring:
Rename "isin" functions to "contains", for grammar. Resolves ticket 5285.
Rename Tor's logging function log() to tor_log(), to avoid conflicts with the natural logarithm function from the system libm. Resolves ticket 7599.

New in Tor 0.2.4.9 Alpha (Jan 16, 2013)

New in Tor 0.2.4.8 Alpha (Jan 15, 2013)

Tor 0.2.4.8-alpha introduces directory guards to reduce user enumeration risks, adds a new stronger and faster circuit handshake, and offers stronger and faster link encryption when both sides support it.
Major features:
Preliminary support for directory guards (proposal 207): when possible, clients now use their entry guards for non-anonymous directory requests. This can help prevent client enumeration. Note that this behavior only works when we have a usable consensus directory, and when options about what to download are more or less standard. In the future we should re-bootstrap from our guards, rather than re-bootstrapping from the preconfigured list of directory sources that ships with Tor. Resolves ticket 6526.
Tor relays and clients now support a better CREATE/EXTEND cell format, allowing the sender to specify multiple address, identity, and handshake types. Implements Robert Ransom's proposal 200; closes ticket 7199.
Major features (new circuit handshake):
Tor now supports a new circuit extension handshake designed by Ian Goldberg, Douglas Stebila, and Berkant Ustaoglu. Our original circuit extension handshake, later called "TAP", was a bit slow (especially on the relay side), had a fragile security proof, and used weaker keys than we'd now prefer. The new circuit handshake uses Dan Bernstein's "curve25519" elliptic-curve Diffie-Hellman function, making it significantly more secure than the older handshake, and significantly faster. Tor can use one of two built-in pure-C curve25519-donna implementations by Adam Langley, or it can link against the "nacl" library for a tuned version if present.
The built-in version is very fast for 64-bit systems when building with GCC. The built-in 32-bit version is still faster than the old TAP protocol, but using libnacl is better on most such hosts.
Clients don't currently use this protocol by default, since comparatively few clients support it so far. To try it, set UseNTorHandshake to 1.
Implements proposal 216; closes ticket 7202.
Major features (better link encryption):
Relays can now enable the ECDHE TLS ciphersuites when available and appropriate. These ciphersuites let us negotiate forward-secure TLS secret keys more safely and more efficiently than with our previous use of Diffie-Hellman modulo a 1024-bit prime. By default, public relays prefer the (faster) P224 group, and bridges prefer the (more common) P256 group; you can override this with the TLSECGroup option.
Enabling these ciphers was a little tricky, since for a long time, clients had been claiming to support them without actually doing so, in order to foil fingerprinting. But with the client-side implementation of proposal 198 in 0.2.3.17-beta, clients can now match the ciphers from recent Firefox versions *and* list the ciphers they actually mean, so relays can believe such clients when they advertise ECDHE support in their TLS ClientHello messages.
This feature requires clients running 0.2.3.17-beta or later, and requires both sides to be running OpenSSL 1.0.0 or later with ECC support. OpenSSL 1.0.1, with the compile-time option "enable-ec_nistp_64_gcc_128", is highly recommended.
Implements the relay side of proposal 198; closes ticket 7200.
Major bugfixes:
Avoid crashing when, as a relay without IPv6-exit support, a client insists on getting an IPv6 address or nothing. Fixes bug 7814; bugfix on 0.2.4.7-alpha.
Minor features:
Improve circuit build timeout handling for hidden services. In particular: adjust build timeouts more accurately depending upon the number of hop-RTTs that a particular circuit type undergoes. Additionally, launch intro circuits in parallel if they timeout, and take the first one to reply as valid.
Work correctly on Unix systems where EAGAIN and EWOULDBLOCK are separate error codes; or at least, don't break for that reason. Fixes bug 7935. Reported by "oftc_must_be_destroyed".
Update to the January 2 2013 Maxmind GeoLite Country database.
Minor features (testing):
Add benchmarks for DH (1024-bit multiplicative group) and ECDH (P-256) Diffie-Hellman handshakes to src/or/bench.
Add benchmark functions to test onion handshake performance.
Minor features (path bias detection):
Alter the Path Bias log messages to be more descriptive in terms of reporting timeouts and other statistics.
Create three levels of Path Bias log messages, as opposed to just two. These are configurable via consensus as well as via the torrc options PathBiasNoticeRate, PathBiasWarnRate, PathBiasExtremeRate. The default values are 0.70, 0.50, and 0.30 respectively.
Separate the log message levels from the decision to drop guards, which also is available via torrc option PathBiasDropGuards. PathBiasDropGuards still defaults to 0 (off).
Deprecate PathBiasDisableRate in favor of PathBiasDropGuards in combination with PathBiasExtremeRate.
Increase the default values for PathBiasScaleThreshold and PathBiasCircThreshold from (200, 20) to (300, 150).
Add in circuit usage accounting to path bias. If we try to use a built circuit but fail for any reason, it counts as path bias. Certain classes of circuits where the adversary gets to pick your destination node are exempt from this accounting. Usage accounting can be specifically disabled via consensus parameter or torrc.
Convert all internal path bias state to double-precision floating point, to avoid roundoff error and other issues.
Only record path bias information for circuits that have completed *two* hops. Assuming end-to-end tagging is the attack vector, this makes us more resilient to ambient circuit failure without any detection capability loss.
Minor bugfixes (log messages):
Rate-limit the "No circuits are opened. Relaxed timeout for a circuit with channel state open..." message to once per hour to keep it from filling the notice logs. Mitigates bug 7799 but does not fix the underlying cause. Bugfix on 0.2.4.7-alpha.
Avoid spurious warnings when configuring multiple client ports of which only some are nonlocal. Previously, we had claimed that some were nonlocal when in fact they weren't. Fixes bug 7836; bugfix on 0.2.3.3-alpha.
Code simplifications and refactoring:
Get rid of a couple of harmless clang warnings, where we compared enums to ints. These warnings are newly introduced in clang 3.2.
Split the onion.c file into separate modules for the onion queue and the different handshakes it supports.
Remove the marshalling/unmarshalling code for sending requests to cpuworkers over a socket, and instead just send structs. The recipient will always be the same Tor binary as the sender, so any encoding is overkill.

New in Tor 0.2.4.7 Alpha (Dec 27, 2012)

Tor 0.2.4.7-alpha introduces a new approach to providing fallback directory mirrors for more robust bootstrapping; fixes more issues where clients with changing network conditions refuse to make any circuits; adds initial support for exiting to IPv6 addresses; resumes being able to update our GeoIP database, and includes the geoip6 file this time; turns off the client-side DNS cache by default due to privacy risks; and fixes a variety of other issues.
Major features (client resilience):
Add a new "FallbackDir" torrc option to use when we can't use a directory mirror from the consensus (either because we lack a consensus, or because they're all down). Currently, all authorities are fallbacks by default, and there are no other default fallbacks, but that will change. This option will allow us to give clients a longer list of servers to try to get a consensus from when first connecting to the Tor network, and thereby reduce load on the directory authorities. Implements proposal 206, "Preconfigured directory sources for bootstrapping". We also removed the old "FallbackNetworkstatus" option, since we never got it working well enough to use it. Closes bug 572.
If we have no circuits open, use a relaxed timeout (the 95-percentile cutoff) until a circuit succeeds. This heuristic should allow Tor to succeed at building circuits even when the network connection drastically changes. Should help with bug 3443.
Major features (IPv6):
Tor now has (alpha) support for exiting to IPv6 addresses. To enable it as an exit node, make sure that you have IPv6 connectivity, then set the IPv6Exit flag to 1. Also make sure your exit policy reads as you would like: the address * applies to all address families, whereas *4 is IPv4 address only, and *6 is IPv6 addresses only. On the client side, you'll need to wait until the authorities have upgraded, wait for enough exits to support IPv6, apply the "IPv6Traffic" flag to a SocksPort, and use Socks5. Closes ticket 5547, implements proposal 117 as revised in proposal 208.
We DO NOT recommend that clients with actual anonymity needs start using IPv6 over Tor yet, since not enough exits support it yet.
Major features (geoip database):
Maxmind began labelling Tor relays as being in country "A1", which breaks by-country node selection inside Tor. Now we use a script to replace "A1" ("Anonymous Proxy") entries in our geoip file with real country codes. This script fixes about 90% of "A1" entries automatically and uses manual country code assignments to fix the remaining 10%. See src/config/README.geoip for details. Fixes bug 6266. Also update to the December 5 2012 Maxmind GeoLite Country database, as modified above.
Major bugfixes (client-side DNS):
Turn off the client-side DNS cache by default. Updating and using the DNS cache is now configurable on a per-client-port level. SOCKSPort, DNSPort, etc lines may now contain {No,}Cache{IPv4,IPv6,}DNS lines to indicate that we shouldn't cache these types of DNS answers when we receive them from an exit node in response to an application request on this port, and {No,}UseCached{IPv4,IPv6,DNS} lines to indicate that if we have cached DNS answers of these types, we shouldn't use them. It's potentially risky to use cached DNS answers at the client, since doing so can indicate to one exit what answers we've gotten for DNS lookups in the past. With IPv6, this becomes especially problematic. Using cached DNS answers for requests on the same circuit would present less linkability risk, since all traffic on a circuit is already linkable, but it would also provide little performance benefit: the exit node caches DNS replies too. Implements a simplified version of Proposal 205. Implements ticket 7570.
Major bugfixes (other):
Alter circuit build timeout measurement to start at the point where we begin the CREATE/CREATE_FAST step (as opposed to circuit initialization). This should make our timeout measurements more uniform. Previously, we were sometimes including ORconn setup time in our circuit build time measurements. Should resolve bug 3443.
Fix an assertion that could trigger in hibernate_go_dormant() when closing an or_connection_t: call channel_mark_for_close() rather than connection_mark_for_close(). Fixes bug 7267. Bugfix on 0.2.4.4-alpha.
Include the geoip6 IPv6 GeoIP database in the tarball. Fixes bug 7655; bugfix on 0.2.4.6-alpha.
Minor features:
Add a new torrc option "ServerTransportListenAddr" to let bridge operators select the address where their pluggable transports will listen for connections. Resolves ticket 7013.
Allow an optional $ before the node identity digest in the controller command GETINFO ns/id/, for consistency with md/id/ and desc/id/. Resolves ticket 7059.
Log packaged cell fullness as part of the heartbeat message. Diagnosis to try to determine the extent of bug 7743.
Minor features (IPv6):
AutomapHostsOnResolve now supports IPv6 addresses. By default, we prefer to hand out virtual IPv6 addresses, since there are more of them and we can't run out. To override this behavior and make IPv4 addresses preferred, set NoPreferIPv6Automap on whatever SOCKSPort or DNSPort you're using for resolving. Implements ticket 7571.
AutomapHostsOnResolve responses are now randomized, to avoid annoying situations where Tor is restarted and applications connect to the wrong addresses.
Never try more than 1000 times to pick a new virtual address when AutomapHostsOnResolve is set. That's good enough so long as we aren't close to handing out our entire virtual address space; if you're getting there, it's best to switch to IPv6 virtual addresses anyway.
Minor bugfixes:
The ADDRMAP command can no longer generate an ill-formed error code on a failed MAPADDRESS. It now says "internal" rather than an English sentence fragment with spaces in the middle. Bugfix on Tor 0.2.0.19-alpha.
Fix log messages and comments to avoid saying "GMT" when we mean "UTC". Fixes bug 6113.
Compile on win64 using mingw64. Fixes bug 7260; patches from "yayooo".
Fix a crash when debugging unit tests on Windows: deallocate a shared library with FreeLibrary, not CloseHandle. Fixes bug 7306; bugfix on 0.2.2.17-alpha. Reported by "ultramage".
Renamed options:
The DirServer option is now DirAuthority, for consistency with current naming patterns. You can still use the old DirServer form.
Code simplification and refactoring:
Move the client-side address-map/virtual-address/DNS-cache code out of connection_edge.c into a new addressmap.c module.
Remove unused code for parsing v1 directories and "running routers" documents. Fixes bug 6887.

New in Tor 0.2.4.6 Alpha (Nov 13, 2012)

Tor 0.2.4.6-alpha fixes an assert bug that has been plaguing relays, makes our defense-in-depth memory wiping more reliable, and begins to count IPv6 addresses in bridge statistics,
Major bug fixes:
Fix an assertion failure that could occur when closing a connection with a spliced rendezvous circuit. Fix for bug 7212; bugfix on Tor 0.2.4.4-alpha.
Tor tries to wipe potentially sensitive data after using it, so that if some subsequent security failure exposes Tor's memory, the damage will be limited. But we had a bug where the compiler was eliminating these wipe operations when it decided that the memory was no longer visible to a (correctly running) program, hence defeating our attempt at defense in depth. We fix that by using OpenSSL's OPENSSL_cleanse() operation, which a compiler is unlikely to optimize away. Future versions of Tor may use a less ridiculously heavy approach for this. Fixes bug 7352. Reported in an article by Andrey Karpov.
Minor features:
Add GeoIP database for IPv6 addresses. The new config option is GeoIPv6File.
Bridge statistics now count bridge clients connecting over IPv6: bridge statistics files now list "bridge-ip-versions" and extra-info documents list "geoip6-db-digest". The control protocol "CLIENTS_SEEN" and "ip-to-country" queries now support IPv6. Initial implementation by "shkoo", addressing ticket 5055.
Minor bug fixes:
Warn when we are binding low ports when hibernation is enabled; previously we had warned when we were _advertising_ low ports with hibernation enabled. Fixes bug 7285; bugfix on 0.2.3.9-alpha.
Fix a harmless bug when opting against publishing a relay descriptor because DisableNetwork is set. Fixes bug 7464; bugfix on 0.2.3.9-alpha.
Add warning message when a managed proxy dies during configuration. Fixes bug 7195; bugfix on 0.2.4.2-alpha.
Fix a linking error when building tor-fw-helper without miniupnp. Fixes bug 7235; bugfix on 0.2.4.2-alpha. Fix by Anthony G. Basile.
Check for closing an or_connection_t without going through correct channel functions; emit a warning and then call connection_or_close_for_error() so we don't assert as in bugs 7212 and 7267.
Compile correctly on compilers without C99 designated initializer support. Fixes bug 7286; bugfix on 0.2.4.4-alpha.
Avoid a possible assert that can occur when channel_send_destroy() is called on a channel in CHANNEL_STATE_CLOSING, CHANNEL_STATE_CLOSED, or CHANNEL_STATE_ERROR when the Tor process is resumed after being blocked for a long interval. Fixes bug 7350; bugfix on 0.2.4.4-alpha.
Fix a memory leak on failing cases of channel_tls_process_certs_cell. Fixes bug 7422; bugfix on 0.2.4.4-alpha.
Code simplification and refactoring:
Start using OpenBSD's implementation of queue.h, so that we don't need to hand-roll our own pointer and list structures whenever we need them. (We can't rely on a sys/queue.h, since some operating systems don't have them, and the ones that do have them don't all present the same extensions.)

New in Tor 0.2.4.5 Alpha (Oct 27, 2012)

Tor 0.2.4.5-alpha comes hard at the heels of 0.2.4.4-alpha, to fix two important security vulnerabilities that could lead to remotely triggerable relay crashes, fix a major bug that was preventing clients from choosing suitable exit nodes, and refactor some of our code.
Major bugfixes (security, also in 0.2.3.24-rc):
Fix a group of remotely triggerable assertion failures related to incorrect link protocol negotiation. Found, diagnosed, and fixed by "some guy from France". Fix for CVE-2012-2250; bugfix on 0.2.3.6-alpha.
Fix a denial of service attack by which any directory authority could crash all the others, or by which a single v2 directory authority could crash everybody downloading v2 directory information. Fixes bug 7191; bugfix on 0.2.0.10-alpha.
Major bugfixes (also in 0.2.3.24-rc):
When parsing exit policy summaries from microdescriptors, we had previously been ignoring the last character in each one, so that "accept 80,443,8080" would be treated by clients as indicating a node that allows access to ports 80, 443, and 808. That would lead to clients attempting connections that could never work, and ignoring exit nodes that would support their connections. Now clients parse these exit policy summaries correctly. Fixes bug 7192; bugfix on 0.2.3.1-alpha.
Minor bugfixes (also in 0.2.3.24-rc):
Clients now consider the ClientRejectInternalAddresses config option when using a microdescriptor consensus stanza to decide whether an exit relay would allow exiting to an internal address. Fixes bug 7190; bugfix on 0.2.3.1-alpha.
Minor bugfixes:
Only disable TLS session ticket support when running as a TLS server. Now clients will blend better with regular Firefox connections. Fixes bug 7189; bugfix on Tor 0.2.3.23-rc.
Code simplification and refactoring:
Start using OpenBSD's implementation of queue.h (originally by Niels Provos).
Move the entry node code from circuitbuild.c to its own file.
Move the circuit build timeout tracking code from circuitbuild.c to its own file.

New in Tor 0.2.3.24 RC (Oct 27, 2012)

New in Tor 0.2.4.4 Alpha (Oct 22, 2012)

Tor 0.2.4.4-alpha adds a new v3 directory authority, fixes a privacy vulnerability introduced by a change in OpenSSL, fixes a remotely triggerable assert, and adds new channel_t and circuitmux_t abstractions that will make it easier to test new connection transport and cell scheduling algorithms.
New directory authorities (also in 0.2.3.23-rc):
Add Faravahar (run by Sina Rabbani) as the ninth v3 directory authority. Closes ticket 5749.
Major bugfixes (security/privacy, also in 0.2.3.23-rc):
Disable TLS session tickets. OpenSSL's implementation was giving our TLS session keys the lifetime of our TLS context objects, when perfect forward secrecy would want us to discard anything that could decrypt a link connection as soon as the link connection was closed. Fixes bug 7139; bugfix on all versions of Tor linked against OpenSSL 1.0.0 or later. Found by Florent Daignière.
Discard extraneous renegotiation attempts once the V3 link protocol has been initiated. Failure to do so left us open to a remotely triggerable assertion failure. Fixes CVE-2012-2249; bugfix on 0.2.3.6-alpha. Reported by "some guy from France".
Internal abstraction features:
Introduce new channel_t abstraction between circuits and or_connection_t to allow for implementing alternate OR-to-OR transports. A channel_t is an abstract object which can either be a cell-bearing channel, which is responsible for authenticating and handshaking with the remote OR and transmitting cells to and from it, or a listening channel, which spawns new cell-bearing channels at the request of remote ORs. Implements part of ticket 6465.
Also new is the channel_tls_t subclass of channel_t, adapting it to the existing or_connection_t code. The V2/V3 protocol handshaking code which formerly resided in command.c has been moved below the channel_t abstraction layer and may be found in channeltls.c now. Implements the rest of ticket 6465.
Introduce new circuitmux_t storing the queue of circuits for a channel; this encapsulates and abstracts the queue logic and circuit selection policy, and allows the latter to be overridden easily by switching out a policy object. The existing EWMA behavior is now implemented as a circuitmux_policy_t. Resolves ticket 6816.
Required libraries:
Tor now requires OpenSSL 0.9.8 or later. OpenSSL 1.0.0 or later is strongly recommended.
Minor features:
Warn users who run hidden services on a Tor client with UseEntryGuards disabled that their hidden services will be vulnerable to http://freehaven.net/anonbib/#hs-attack06 (the attack which motivated Tor to support entry guards in the first place). Resolves ticket 6889.
Tor now builds correctly on Bitrig, an OpenBSD fork. Patch from dhill. Resolves ticket 6982.
Minor bugfixes (also in 0.2.3.23-rc):
Don't serve or accept v2 hidden service descriptors over a relay's DirPort. It's never correct to do so, and disabling it might make it more annoying to exploit any bugs that turn up in the descriptor-parsing code. Fixes bug 7149.
Fix two cases in src/or/transports.c where we were calling fmt_addr() twice in a parameter list. Bug found by David Fifield. Fixes bug 7014; bugfix on 0.2.3.9-alpha.
Fix memory leaks whenever we logged any message about the "path bias" detection. Fixes bug 7022; bugfix on 0.2.3.21-rc.
When relays refuse a "create" cell because their queue of pending create cells is too big (typically because their cpu can't keep up with the arrival rate), send back reason "resource limit" rather than reason "internal", so network measurement scripts can get a more accurate picture. Fixes bug 7037; bugfix on 0.1.1.11-alpha.
Minor bugfixes:
Command-line option "--version" implies "--quiet". Fixes bug 6997.
Free some more still-in-use memory at exit, to make hunting for memory leaks easier. Resolves bug 7029.
When a Tor client gets a "truncated" relay cell, the first byte of its payload specifies why the circuit was truncated. We were ignoring this 'reason' byte when tearing down the circuit, resulting in the controller not being told why the circuit closed. Now we pass the reason from the truncated cell to the controller. Bugfix on 0.1.2.3-alpha; fixes bug 7039.
Downgrade "Failed to hand off onionskin" messages to "debug" severity, since they're typically redundant with the "Your computer is too slow" messages. Fixes bug 7038; bugfix on 0.2.2.16-alpha.
Make clients running with IPv6 bridges connect over IPv6 again, even without setting new config options ClientUseIPv6 and ClientPreferIPv6ORPort. Fixes bug 6757; bugfix on 0.2.4.1-alpha.
Use square brackets around IPv6 addresses in numerous places that needed them, including log messages, HTTPS CONNECT proxy requests, TransportProxy statefile entries, and pluggable transport extra-info lines. Fixes bug 7011; patch by David Fifield.
Code refactoring and cleanup:
Source files taken from other packages now reside in src/ext; previously they were scattered around the rest of Tor.
Avoid use of reserved identifiers in our C code. The C standard doesn't like us declaring anything that starts with an underscore, so let's knock it off before we get in trouble. Fix for bug 1031; bugfix on the first Tor commit.

New in Tor 0.2.3.23 RC (Oct 22, 2012)

Tor 0.2.3.23-rc adds a new v3 directory authority, fixes a privacy vulnerability introduced by a change in OpenSSL, and fixes a variety of smaller bugs in preparation for the release.
New directory authorities:
Add Faravahar (run by Sina Rabbani) as the ninth v3 directory authority. Closes ticket 5749.
Major bugfixes (security/privacy):
Disable TLS session tickets. OpenSSL's implementation was giving our TLS session keys the lifetime of our TLS context objects, when perfect forward secrecy would want us to discard anything that could decrypt a link connection as soon as the link connection was closed. Fixes bug 7139; bugfix on all versions of Tor linked against OpenSSL 1.0.0 or later. Found by Florent Daignière.
Discard extraneous renegotiation attempts once the V3 link protocol has been initiated. Failure to do so left us open to a remotely triggerable assertion failure. Fixes CVE-2012-2249; bugfix on 0.2.3.6-alpha. Reported by "some guy from France".
Major bugfixes:
Fix a possible crash bug when checking for deactivated circuits in connection_or_flush_from_first_active_circuit(). Fixes bug 6341; bugfix on 0.2.2.7-alpha. Bug report and fix received pseudonymously.
Minor bugfixes (on 0.2.3.x):
Fix two cases in src/or/transports.c where we were calling fmt_addr() twice in a parameter list. Bug found by David Fifield. Fixes bug 7014; bugfix on 0.2.3.9-alpha.
Convert an assert in the pathbias code to a log message. The assert appears to only be triggerable by Tor2Web mode. Fixes bug 6866; bugfix on 0.2.3.17-beta.
Fix memory leaks whenever we logged any message about the "path bias" detection. Fixes bug 7022; bugfix on 0.2.3.21-rc.
Minor bugfixes (on 0.2.2.x and earlier):
Don't serve or accept v2 hidden service descriptors over a relay's DirPort. It's never correct to do so, and disabling it might make it more annoying to exploit any bugs that turn up in the descriptor-parsing code. Fixes bug 7149.
When relays refuse a "create" cell because their queue of pending create cells is too big (typically because their cpu can't keep up with the arrival rate), send back reason "resource limit" rather than reason "internal", so network measurement scripts can get a more accurate picture. Bugfix on 0.1.1.11-alpha; fixes bug 7037.
Correct file sizes when reading binary files on Cygwin, to avoid a bug where Tor would fail to read its state file. Fixes bug 6844; bugfix on 0.1.2.7-alpha.
Avoid undefined behaviour when parsing the list of supported rendezvous/introduction protocols in a hidden service descriptor. Previously, Tor would have confused (as-yet-unused) protocol version numbers greater than 32 with lower ones on many platforms. Fixes bug 6827; bugfix on 0.2.0.10-alpha. Found by George Kadianakis.
Documentation fixes:
Clarify that hidden services are TCP only. Fixes bug 6024.

New in Tor 0.2.2.39 (Sep 12, 2012)

New in Tor 0.2.3.22 RC (Sep 12, 2012)

New in Tor 0.2.4.2 Alpha (Sep 11, 2012)

Major features:
Automatically forward the TCP ports of pluggable transport proxies using tor-fw-helper if PortForwarding is enabled. Implements ticket 4567.
Major bugfixes:
Raise the default BandwidthRate/BandwidthBurst values from 5MB/10MB to 1GB/1GB. The previous defaults were intended to be "basically infinite", but it turns out they're now limiting our 100mbit+ relays and bridges. Fixes bug 6605; bugfix on 0.2.0.10-alpha (the last time we raised it).
Minor features:
Detect when we're running with a version of OpenSSL other than the one we compiled with. This has occasionally given people hard-to- track-down errors.
Log fewer lines at level "notice" about our OpenSSL and Libevent versions and capabilities when everything is going right. Resolves part of ticket 6736.
Directory authorities no long accept descriptors for any version of Tor before 0.2.2.35, or for any 0.2.3 release before 0.2.3.10-alpha. These versions are insecure, unsupported, or both. Implements ticket 6789.
Minor bugfixes:
Rename the (internal-use-only) UsingTestingNetworkDefaults option to start with a triple-underscore so the controller won't touch it. Patch by Meejah. Fixes bug 3155. Bugfix on 0.2.2.23-alpha.
Avoid segfault when starting up having run with an extremely old version of Tor and parsing its state file. Fixes bug 6801; bugfix on 0.2.2.23-alpha.
Rename the (testing-use-only) _UseFilteringSSLBufferevents option so it doesn't start with _. Fixes bug 3155. Bugfix on 0.2.3.1-alpha.
Don't follow the NULL pointer if microdescriptor generation fails. (This does not appear to be triggerable, but it's best to be safe.) Found by "f. tp.". Fixes bug 6797; bugfix on 0.2.4.1-alpha.
Fix mis-declared dependencies on src/common/crypto.c and src/or/tor_main.c that could break out-of-tree builds under some circumstances. Fixes bug 6778; bugfix on 0.2.4.1-alpha.
Avoid a warning when building common_sha1.i out of tree. Fixes bug 6778; bugfix on 0.2.4.1-alpha.
Fix a harmless (in this case) build warning for implicitly converting a strlen() to an int. Bugfix on 0.2.4.1-alpha.
Removed features:
Now that all versions before 0.2.2.x are disallowed, we no longer need to work around their missing features. Thus we can remove a bunch of compatibility code.
Code refactoring:
Tweak tor-fw-helper to accept an arbitrary amount of arbitrary TCP ports to forward. In the past it only accepted two ports: the ORPort and the DirPort.

New in Tor 0.2.4.1 Alpha (Sep 6, 2012)

Major features (bridges):
Bridges now report the pluggable transports they support to the bridge authority, so it can pass the supported transports on to bridgedb and/or eventually do reachability testing. Implements ticket 3589.
Major features (IPv6):
Bridge authorities now accept IPv6 bridge addresses and include them in network status documents. Implements ticket 5534.
Clients who set "ClientUseIPv6 1" may connect to entry nodes over IPv6. Set "ClientPreferIPv6ORPort 1" to make this even more likely to happen. Implements ticket 5535.
All kind of relays, not just bridges, can now advertise an IPv6 OR port. Implements ticket 6362.
Directory authorities vote on IPv6 OR ports using the new consensus method 14. Implements ticket 6363.
Major features (build):
Switch to a nonrecursive Makefile structure. Now instead of each Makefile.am invoking other Makefile.am's, there is a master Makefile.am that includes the others. This change makes our build process slightly more maintainable, and improves parallelism for building with make -j. Original patch by Stewart Smith; various fixes by Jim Meyering.
Where available, we now use automake's "silent" make rules by default, so that warnings are easier to spot. You can get the old behavior with "make V=1". Patch by Stewart Smith for ticket 6522.
Minor features (code security and spec conformance):
Clear keys and key-derived material left on the stack in rendservice.c and rendclient.c. Check return value of crypto_pk_write_private_key_to_string() in end_service_load_keys(). These fixes should make us more forward-secure against cold-boot attacks and the like. Fixes bug 2385.
Reject EXTEND cells sent to nonexistent streams. According to the spec, an EXTEND cell sent to _any_ nonzero stream ID is invalid, but we were only checking for stream IDs that were currently in use. Found while hunting for more instances of bug 6271. Bugfix on 0.0.2pre8, which introduced incremental circuit construction.
Minor features (streamlining);
No longer include the "opt" prefix when generating routerinfos or v2 directories: it has been needless since Tor 0.1.2. Closes ticket 5124.
Remove some now-needless code that tried to aggressively flush OR connections as data was added to them. Since 0.2.0.1-alpha, our cell queue logic has saved us from the failure mode that this code was supposed to prevent. Removing this code will limit the number of baroque control flow paths through Tor's network logic. Reported pseudonymously on IRC. Fixes bug 6468; bugfix on 0.2.0.1-alpha.
Minor features (controller):
Add a "GETINFO signal/names" control port command. Implements ticket 3842.
Provide default values for all options via "GETINFO config/defaults". Implements ticket 4971.
Minor features (IPv6):
New config option "AuthDirHasIPv6Connectivity 1" that directory authorities should set if they have IPv6 connectivity and want to do reachability tests for IPv6 relays. Implements feature 5974.
A relay with an IPv6 OR port now sends that address in NETINFO cells (in addition to its other address). Implements ticket 6364.
Minor features (log messages):
Omit the first heartbeat log message, because it never has anything useful to say, and it clutters up the bootstrapping messages. Resolves ticket 6758.
Don't log about reloading the microdescriptor cache at startup. Our bootstrap warnings are supposed to tell the user when there's a problem, and our bootstrap notices say when there isn't. Resolves ticket 6759; bugfix on 0.2.2.6-alpha.
Don't log "I learned some more directory information" when we're reading cached directory information. Reserve it for when new directory information arrives in response to a fetch. Resolves ticket 6760.
Prevent rounding error in path bias counts when scaling them down, and use the correct scale factor default. Also demote some path bias related log messages down a level and make others less scary sounding. Fixes bug 6647. Bugfix against 0.2.3.17-beta.
We no longer warn so much when generating manpages from their asciidoc source.
Code simplifications and refactoring:
Enhance our internal sscanf replacement so that we can eliminate the last remaining uses of the system sscanf. (Though those uses of sscanf were safe, sscanf itself is generally error prone, so we want to eliminate when we can.) Fixes ticket 4195 and Coverity CID 448.
Move ipv6_preferred from routerinfo_t to node_t. Addresses bug 4620.
Move last_reachable and testing_since from routerinfo_t to node_t. Implements ticket 5529.
Add replaycache_t structure, functions and unit tests, then refactor rend_service_introduce() to be more clear to read, improve, debug, and test. Resolves bug 6177.
Finally remove support for malloc_good_size and malloc_usable_size. We had hoped that these functions would let us eke a little more memory out of our malloc implementation. Unfortunately, the only implementations that provided these functions are also ones that are already efficient about not overallocation: they never got us more than 7 or so bytes per allocation. Removing them saves us a little code complexity and a nontrivial amount of build complexity.
New requirements:
Tor maintainers now require Automake version 1.9 or later to build Tor from the Git repository. (Automake is not required when building from a source distribution.)

New in Tor 0.2.3.21 RC (Sep 6, 2012)

Major bug fixes (security):
Tear down the circuit if we get an unexpected SENDME cell. Clients could use this trick to make their circuits receive cells faster than our flow control would have allowed, or to gum up the network, or possibly to do targeted memory denial-of-service attacks on entry nodes. Fixes bug 6252. Bugfix on the 54th commit on Tor -- from July 2002, before the release of Tor 0.0.0. We had committed this patch previously, but we had to revert it because of bug 6271. Now that 6271 is fixed, this patch appears to work.
Reject any attempt to extend to an internal address. Without this fix, a router could be used to probe addresses on an internal network to see whether they were accepting connections. Fixes bug 6710; bugfix on 0.0.8pre1.
Do not crash when comparing an address with port value 0 to an address policy. This bug could have been used to cause a remote assertion failure by or against directory authorities, or to allow some applications to crash clients. Fixes bug 6690; bugfix on 0.2.1.10-alpha.
Major bug fixes:
Remove the upper bound on microdescriptor length. We were hitting the limit for routers with complex exit policies or family declarations, causing clients to not use them. Fixes the first piece of bug 6404; fix on 0.2.2.6-alpha.
Detect "ORPort 0" as meaning, uniformly, that we're not running as a relay. Previously, some of our code would treat the presence of any ORPort line as meaning that we should act like a relay, even though our new listener code would correctly not open any ORPorts for ORPort 0. Similar bugs in other Port options are also fixed. Fixes the first half of bug 6507; bugfix on 0.2.3.3-alpha.
Minor bug fixes:
Avoid a pair of double-free and use-after-mark bugs that can occur with certain timings in canceled and re-received DNS requests. Fixes bug 6472; bugfix on 0.0.7rc1.
Fix build and 64-bit compile warnings from --enable-openbsd-malloc. Fixes bug 6379. Bugfix on 0.2.0.20-rc.
Allow one-hop directory fetching circuits the full "circuit build timeout" period, rather than just half of it, before failing them and marking the relay down. This fix should help reduce cases where clients declare relays (or worse, bridges) unreachable because the TLS handshake takes a few seconds to complete. Fixes bug 6743; bugfix on 0.2.2.2-alpha, where we changed the timeout from a static 30 seconds.
Authorities no longer include any router in their microdescriptor consensuses for which they couldn't generate or agree on a microdescriptor. Fixes the second piece of bug 6404; fix on 0.2.2.6-alpha.
Detect and reject attempts to specify both "FooPort" and "FooPort 0" in the same configuration domain. (It's still okay to have a FooPort in your configuration file, and use "FooPort 0" on the command line to disable it.) Fixes the second half of bug 6507; bugfix on 0.2.3.3-alpha.
Make wildcarded addresses (that is, ones beginning with "*.") work when provided via the controller's MapAddress command. Previously, they were accepted, but we never actually noticed that they were wildcards. Fixes bug 6244; bugfix on 0.2.3.9-alpha.
Avoid crashing on a malformed state file where EntryGuardPathBias precedes EntryGuard. Fixes bug 6774; bugfix on 0.2.3.17-beta.
Add a (probably redundant) memory clear between iterations of the router status voting loop, to prevent future coding errors where data might leak between iterations of the loop. Resolves ticket 6514.
Minor bug fixes (log messages):
Downgrade "set buildtimeout to low value" messages to "info" severity; they were never an actual problem, there was never anything reasonable to do about them, and they tended to spam logs from time to time. Fixes bug 6251; bugfix on 0.2.2.2-alpha.
Downgrade path-bias warning messages to "info". We'll try to get them working better in 0.2.4. Add internal circuit construction state to protect against the noisy warn message "Unexpectedly high circuit_successes". Also add some additional rate-limited notice messages to help determine the root cause of the warn. Fixes bug 6475. Bugfix against 0.2.3.17-beta.
Move log message when unable to find a microdesc in a routerstatus entry to parse time. Previously we'd spam this warning every time we tried to figure out which microdescriptors to download. Fixes the third piece of bug 6404; fix on 0.2.3.18-rc.
Minor features:
Consider new, removed or changed IPv6 OR ports a non-cosmetic change when the authority is deciding whether to accept a newly uploaded descriptor. Implements ticket 6423.
Add missing documentation for consensus and microdesc files. Resolves ticket 6732.

New in Tor 0.2.2.38 (Aug 13, 2012)

New in Tor 0.2.3.20 RC (Aug 6, 2012)

o Security fixes:
Avoid read-from-freed-memory and double-free bugs that could occur when a DNS request fails while launching it. Fixes bug 6480; bugfix on 0.2.0.1-alpha.
Avoid an uninitialized memory read when reading a vote or consensus document that has an unrecognized flavor name. This read could lead to a remote crash bug. Fixes bug 6530; bugfix on 0.2.2.6-alpha.
Try to leak less information about what relays a client is choosing to a side-channel attacker. Previously, a Tor client would stop iterating through the list of available relays as soon as it had chosen one, thus finishing a little earlier when it picked a router earlier in the list. If an attacker can recover this timing information (nontrivial but not proven to be impossible), they could learn some coarse-grained information about which relays a client was picking (middle nodes in particular are likelier to be affected than exits). The timing attack might be mitigated by other factors (see bug 6537 for some discussion), but it's best not to take chances. Fixes bug 6537; bugfix on 0.0.8rc1.
Minor features:
Try to make the warning when giving an obsolete SOCKSListenAddress a little more useful.
Terminate active server managed proxies if Tor stops being a relay. Addresses parts of bug 6274; bugfix on 0.2.3.6-alpha.
Provide a better error message about possible OSX Asciidoc failure reasons. Fixes bug 6436.
Warn when Tor is configured to use accounting in a way that can link a hidden service to some other hidden service or public address. Resolves ticket 6490.
Minor bug fixes:
Check return value of fputs() when writing authority certificate file. Fixes Coverity issue 709056; bugfix on 0.2.0.1-alpha.
Ignore ServerTransportPlugin lines when Tor is not configured as a relay. Fixes bug 6274; bugfix on 0.2.3.6-alpha.
When disabling guards for having too high a proportion of failed circuits, make sure to look at each guard. Fixes bug 6397; bugfix on 0.2.3.17-beta.
Packaging (RPM):
Update our default RPM spec files to work with mock and rpmbuild on RHEL/Fedora. They have an updated set of dependencies and conflicts, a fix for an ancient typo when creating the "_tor" user, and better instructions. Thanks to Ondrej Mikle for the patch series. Fixes bug 6043.
Testing:
Make it possible to set the TestingTorNetwork configuration option using AlternateDirAuthority and AlternateBridgeAuthority as an alternative to setting DirServer. Addresses ticket 6377.
Documentation:
Clarify the documentation for the Alternate*Authority options. Fixes bug 6387.
Fix some typos in the manpages. Patch from A. Costa. Fixes bug 6500.
Code simplification and refactoring:
Do not use SMARTLIST_FOREACH for any loop whose body exceeds 10 lines. Also, don't nest them. Doing so in the past has led to hard-to-debug code. The new style is to use the SMARTLIST_FOREACH_{BEGIN,END} pair. Addresses issue 6400.

New in Tor 0.2.3.19 RC (Jul 7, 2012)

New in Tor 0.2.3.18 RC (Jun 30, 2012)

MAJOR BUGFIXES:
Allow wildcarded mapaddress targets to be specified on the controlport. Partially fixes bug 6244; bugfix on 0.2.3.9-alpha.
Make our linker option detection code more robust against linkers such as on FreeBSD 8, where a bad combination of options completes successfully but makes an unrunnable binary. Fixes bug 6173; bugfix on 0.2.3.17-beta.
MINOR BUGFIXES (ON 0.2.2.X AND EARLIER):
Avoid a false positive in the util/threads unit test by increasing the maximum timeout time. Fixes bug 6227; bugfix on 0.2.0.4-alpha.
Replace "Sending publish request" log messages with "Launching upload", so that they no longer confusingly imply that we're sending something to a directory we might not even be connected to yet. Fixes bug 3311; bugfix on 0.2.0.10-alpha.
Make sure to set *socket_error in all error cases in connection_connect(), so it can't produce a warning about errno being zero from errno_to_orconn_end_reason(). Bugfix on 0.2.1.1-alpha; resolves ticket 6028.
Downgrade "Got a certificate, but we already have it" log messages from warning to info, except when we're a dirauth. Fixes bug 5238; bugfix on 0.2.1.7-alpha.
When checking for requested signatures on the latest consensus before serving it to a client, make sure to check the right consensus flavor. Bugfix on 0.2.2.6-alpha.
Downgrade "eventdns rejected address" message to LOG_PROTOCOL_WARN. Fixes bug 5932; bugfix on 0.2.2.7-alpha.
MINOR BUGFIXES (ON 0.2.3.X):
Make format_helper_exit_status() avoid unnecessary space padding and stop confusing log_from_pipe(). Fixes ticket 5557; bugfix on 0.2.3.1-alpha.
Downgrade a message about cleaning the microdescriptor cache to "info" from "notice". Fixes bug 6238; bugfix on 0.2.3.1-alpha.
Log a BUG message at severity INFO if we have a networkstatus with a missing entry for some microdescriptor. Continues on a patch to 0.2.3.2-alpha.
Improve the log message when a managed proxy fails to launch. Fixes bug 5099; bugfix on 0.2.3.6-alpha.
Don't do DNS lookups when parsing corrupted managed proxy protocol messages. Fixes bug 6226; bugfix on 0.2.3.6-alpha.
When formatting wildcarded address mappings for the controller, be sure to include "*." as appropriate. Partially fixes bug 6244; bugfix on 0.2.3.9-alpha.
Avoid a warning caused by using strcspn() from glibc with clang 3.0. Bugfix on 0.2.3.13-alpha.
Stop logging messages about running with circuit timeout learning enabled at severity LD_BUG. Fixes bug 6169; bugfix on 0.2.3.17-beta.
Disable a spurious warning about reading on a marked and flushing connection. We shouldn't be doing that, but apparently we sometimes do. Fixes bug 6203; bugfix on 0.2.3.17-beta.
Fix a bug that stopped AllowDotExit from working on addresses that had an entry in the DNS cache. Fixes bug 6211; bugfix on 0.2.3.17-beta.
CODE SIMPLIFICATION, REFACTORING, UNIT TESTS:
Move tor_gettimeofday_cached() into compat_libevent.c, and use Libevent's notion of cached time when possible.
Remove duplicate code for invoking getrlimit() from control.c.
Add a unit test for the environment_variable_names_equal function.
DOCUMENTATION:
Document the --defaults-torrc option, and the new (in 0.2.3) semantics for overriding, extending, and clearing lists of options. Closes bug 4748.

New in Tor 0.2.3.17 Beta (Jun 16, 2012)

Major features:
Enable gcc and ld hardening by default. Resolves ticket 5210.
Update TLS cipher list to match Firefox 8 and later. Resolves ticket 4744.
Implement the client side of proposal 198: remove support for clients falsely claiming to support standard ciphersuites that they can actually provide. As of modern OpenSSL versions, it's not necessary to fake any standard ciphersuite, and doing so prevents us from using better ciphersuites in the future, since servers can't know whether an advertised ciphersuite is really supported or not. Some hosts -- notably, ones with very old versions of OpenSSL or where OpenSSL has been built with ECC disabled -- will stand out because of this change; TBB users should not be affected.
Major bugfixes:
Change the default value for DynamicDHGroups (introduced in 0.2.3.9-alpha) to 0. This feature can make Tor relays less identifiable by their use of the mod_ssl DH group, but at the cost of some usability (#4721) and bridge tracing (#6087) regressions. Resolves ticket 5598.
Send a CRLF at the end of each STATUS_* control protocol event. This bug tickled a bug in Vidalia which would make it freeze. Fixes bug 6094; bugfix on 0.2.3.16-alpha.
Minor bugfixes:
Disable writing on marked-for-close connections when they are blocked on bandwidth, to prevent busy-looping in Libevent. Fixes bug 5263; bugfix on 0.0.2pre13, where we first added a special case for flushing marked connections.
Detect SSL handshake even when the initial attempt to write the server hello fails. Fixes bug 4592; bugfix on 0.2.0.13-alpha.
Change the AllowDotExit rules so they should actually work. We now enforce AllowDotExit only immediately after receiving an address via SOCKS or DNSPort: other sources are free to provide .exit addresses after the resolution occurs. Fixes bug 3940; bugfix on 0.2.2.1-alpha.
Fix a (harmless) integer overflow in cell statistics reported by some fast relays. Fixes bug 5849; bugfix on 0.2.2.1-alpha.
Make sure circuitbuild.c checks LearnCircuitBuildTimeout in all the right places and never depends on the consensus parameters or computes adaptive timeouts when it is disabled. Fixes bug 5049; bugfix on 0.2.2.14-alpha.
When building Tor on Windows with -DUNICODE (not default), ensure that error messages, filenames, and DNS server names are always NUL-terminated when we convert them to a single-byte encoding. Fixes bug 5909; bugfix on 0.2.2.16-alpha.
Make Tor build correctly again with -DUNICODE -D_UNICODE defined. Fixes bug 6097; bugfix on 0.2.2.16-alpha.
Fix an edge case where TestingTorNetwork is set but the authorities and relays all have an uptime of zero, where the private Tor network could briefly lack support for hidden services. Fixes bug 3886; bugfix on 0.2.2.18-alpha.
Correct the manpage's descriptions for the default values of DirReqStatistics and ExtraInfoStatistics. Fixes bug 2865; bugfix on 0.2.3.1-alpha.
Fix the documentation for the --hush and --quiet command line options, which changed their behavior back in 0.2.3.3-alpha.
Fix compilation warning with clang 3.1. Fixes bug 6141; bugfix on 0.2.3.11-alpha.
Minor features:
Rate-limit the "Weighted bandwidth is 0.000000" message, and add more information to it, so that we can track it down in case it returns again. Mitigates bug 5235.
Check CircuitBuildTimeout and LearnCircuitBuildTimeout in options_validate(); warn if LearnCircuitBuildTimeout is disabled and CircuitBuildTimeout is set unreasonably low. Resolves ticket 5452.
Warn the user when HTTPProxy, but no other proxy type, is configured. This can cause surprising behavior: it doesn't send all of Tor's traffic over the HTTPProxy -- it sends unencrypted directory traffic only. Resolves ticket 4663.
Issue a notice if a guard completes less than 40% of your circuits. Threshold is configurable by torrc option PathBiasNoticeRate and consensus parameter pb_noticepct. There is additional, off-by- default code to disable guards which fail too many circuits. Addresses ticket 5458.
Update to the June 6 2012 Maxmind GeoLite Country database.
Code simplifications and refactoring:
Remove validate_pluggable_transports_config(): its warning message is now handled by connection_or_connect().

New in Tor 0.2.2.37 (Jun 13, 2012)

New in Tor 0.2.3.16 Alpha (Jun 6, 2012)

Major bugfixes (general):
Work around a bug in OpenSSL that broke renegotiation with TLS 1.1 and TLS 1.2. Without this workaround, all attempts to speak the v2 Tor connection protocol when both sides were using OpenSSL 1.0.1 would fail. Resolves ticket 6033.
When waiting for a client to renegotiate, don't allow it to add any bytes to the input buffer. This fixes a potential DoS issue. Fixes bugs 5934 and 6007; bugfix on 0.2.0.20-rc.
Pass correct OR address to managed proxies (like obfsproxy), even when ORListenAddress is used. Fixes bug 4865; bugfix on 0.2.3.9-alpha.
The advertised platform of a router now includes only its operating system's name (e.g., "Linux", "Darwin", "Windows 7"), and not its service pack level (for Windows) or its CPU architecture (for Unix). We also no longer include the "git-XYZ" tag in the version. Resolves part of bug 2988.
Major bugfixes (clients):
If we are unable to find any exit that supports our predicted ports, stop calling them predicted, so that we don't loop and build hopeless circuits indefinitely. Fixes bug 3296; bugfix on 0.0.9pre6, which introduced predicted ports.
Fix an edge case where if we fetch or publish a hidden service descriptor, we might build a 4-hop circuit and then use that circuit for exiting afterwards -- even if the new last hop doesn't obey our ExitNodes config option. Fixes bug 5283; bugfix on 0.2.0.10-alpha.
Check at each new consensus whether our entry guards were picked long enough ago that we should rotate them. Previously, we only did this check at startup, which could lead to us holding a guard indefinitely. Fixes bug 5380; bugfix on 0.2.1.14-rc.
When fetching a bridge descriptor from a bridge authority, always do so anonymously, whether we have been able to open circuits or not. Partial fix for bug 1938; bugfix on 2.0.7-alpha. This behavior makes it *safer* to use UpdateBridgesFromAuthority, but we'll need to wait for bug 6010 before it's actually usable.
Major bugfixes (directory authorities):
When computing weight parameters, behave more robustly in the presence of a bad bwweightscale value. Previously, the authorities would crash if they agreed on a sufficiently broken weight_scale value: now, they use a reasonable default and carry on. Partial fix for 5786; bugfix on 0.2.2.17-alpha.
Check more thoroughly to prevent a rogue authority from double-voting on any consensus directory parameter. Previously, authorities would crash in this case if the total number of votes for any parameter exceeded the number of active voters, but would let it pass otherwise. Partial fix for bug 5786; bugfix on 0.2.2.2-alpha.
Minor features:
Rate-limit log messages when asked to connect anonymously to a private address. When these hit, they tended to hit fast and often. Also, don't bother trying to connect to addresses that we are sure will resolve to 127.0.0.1: getting 127.0.0.1 in a directory reply makes us think we have been lied to, even when the address the client tried to connect to was "localhost." Resolves ticket 2822.
Allow packagers to insert an extra string in server descriptor platform lines by setting the preprocessor variable TOR_BUILD_TAG. Resolves the rest of ticket 2988.
Raise the threshold of server descriptors needed (75%) and exit server descriptors needed (50%) before we will declare ourselves bootstrapped. This will make clients start building circuits a little later, but makes the initially constructed circuits less skewed and less in conflict with further directory fetches. Fixes ticket 3196.
Close any connection that sends unrecognized junk before the handshake. Solves an issue noted in bug 4369.
Improve log messages about managed transports. Resolves ticket 5070.
Tag a bridge's descriptor as "never to be sent unencrypted". This shouldn't matter, since bridges don't open non-anonymous connections to the bridge authority and don't allow unencrypted directory connections from clients, but we might as well make sure. Closes bug 5139.
Expose our view of whether we have gone dormant to the controller, via a new "GETINFO dormant" value. Torbutton and other controllers can use this to avoid doing periodic requests through Tor while it's dormant (bug 4718). Fixes bug 5954.
Tell GCC and Clang to check for any errors in format strings passed to the tor_v*(print|scan)f functions.
Update to the May 1 2012 Maxmind GeoLite Country database.
Minor bugfixes (already included in 0.2.2.36):
Reject out-of-range times like 23:59:61 in parse_rfc1123_time(). Fixes bug 5346; bugfix on 0.0.8pre3.
Correct parsing of certain date types in parse_http_time(). Without this patch, If-Modified-Since would behave incorrectly. Fixes bug 5346; bugfix on 0.2.0.2-alpha. Patch from Esteban Manchado Velázques.
Make our number-parsing functions always treat too-large values as an error, even when those values exceed the width of the underlying type. Previously, if the caller provided these functions with minima or maxima set to the extreme values of the underlying integer type, these functions would return those values on overflow rather than treating overflow as an error. Fixes part of bug 5786; bugfix on 0.0.9.
If we hit the error case where routerlist_insert() replaces an existing (old) server descriptor, make sure to remove that server descriptor from the old_routers list. Fix related to bug 1776. Bugfix on 0.2.2.18-alpha.
Clarify the behavior of MaxCircuitDirtiness with hidden service circuits. Fixes issue 5259.
Minor bugfixes (coding cleanup, on 0.2.2.x and earlier):
Prevent a null-pointer dereference when receiving a data cell for a nonexistent stream when the circuit in question has an empty deliver window. We don't believe this is triggerable, since we don't currently allow deliver windows to become empty, but the logic is tricky enough that it's better to make the code robust. Fixes bug 5541; bugfix on 0.0.2pre14.
Fix a memory leak when trying to launch a DNS request when the network is disabled or the nameservers are unconfigurable. Fixes bug 5916; bugfix on Tor 0.1.2.1-alpha (for the unconfigurable nameserver case) and on 0.2.3.9-alpha (for the DisableNetwork case).
Don't hold a windows file handle open for every file mapping; the file mapping handle is sufficient. Fixes bug 5951; bugfix on 0.1.2.1-alpha.
Avoid O(n^2) performance characteristics when parsing a large extrainfo cache. Fixes bug 5828; bugfix on 0.2.0.1-alpha.
Format more doubles with %f, not %lf. Patch from grarpamp to make Tor build correctly on older BSDs again. Fixes bug 3894; bugfix on Tor 0.2.0.8-alpha.
Make our replacement implementation of strtok_r() compatible with the standard behavior of strtok_r(). Patch by nils. Fixes bug 5091; bugfix on 0.2.2.1-alpha.
Fix a NULL-pointer dereference on a badly formed SETCIRCUITPURPOSE command. Found by mikeyc. Fixes bug 5796; bugfix on 0.2.2.9-alpha.
Fix a build warning with Clang 3.1 related to our use of vasprint. Fixes bug 5969. Bugfix on 0.2.2.11-alpha.
Defensively refactor rend_mid_rendezvous() so that protocol violations and length checks happen in the beginning. Fixes bug 5645.
Set _WIN32_WINNT to 0x0501 consistently throughout the code, so that IPv6 stuff will compile on MSVC, and compilation issues will be easier to track down. Fixes bug 5861.
Minor bugfixes (correctness, on 0.2.2.x and earlier):
Exit nodes now correctly report EADDRINUSE and EADDRNOTAVAIL as resource exhaustion, so that clients can adjust their load to try other exits. Fixes bug 4710; bugfix on 0.1.0.1-rc, which started using END_STREAM_REASON_RESOURCELIMIT.
Don't check for whether the address we're using for outbound connections has changed until after the outbound connection has completed. On Windows, getsockname() doesn't succeed until the connection is finished. Fixes bug 5374; bugfix on 0.1.1.14-alpha.
If the configuration tries to set MyFamily on a bridge, refuse to do so, and warn about the security implications. Fixes bug 4657; bugfix on 0.2.0.3-alpha.
If the client fails to set a reasonable set of ciphersuites during its v2 handshake renegotiation, allow the renegotiation to continue nevertheless (i.e. send all the required certificates). Fixes bug 4591; bugfix on 0.2.0.20-rc.
When we receive a SIGHUP and the controller __ReloadTorrcOnSIGHUP option is set to 0 (which Vidalia version 0.2.16 now does when a SAVECONF attempt fails), perform other actions that SIGHUP usually causes (like reopening the logs). Fixes bug 5095; bugfix on 0.2.1.9-alpha.
If we fail to write a microdescriptor to the disk cache, do not continue replacing the old microdescriptor file. Fixes bug 2954; bugfix on 0.2.2.6-alpha.
Exit nodes don't need to fetch certificates for authorities that they don't recognize; only directory authorities, bridges, and caches need to do that. Fixes part of bug 2297; bugfix on 0.2.2.11-alpha.
Correctly handle checking the permissions on the parent directory of a control socket in the root directory. Bug found by Esteban Manchado VelÃ¡zquez. Fixes bug 5089; bugfix on Tor 0.2.2.26-beta.
When told to add a bridge with the same digest as a preexisting bridge but a different addr:port, change the addr:port as requested. Previously we would not notice the change. Fixes half of bug 5603; fix on 0.2.2.26-beta.
End AUTHCHALLENGE error messages (in the control protocol) with a CRLF. Fixes bug 5760; bugfix on 0.2.2.36 and 0.2.3.13-alpha.
Minor bugfixes (on 0.2.3.x):
Turn an assertion (that the number of handshakes received as a server is not < 1) into a warning. Fixes bug 4873; bugfix on 0.2.3.1-alpha.
Format IPv4 addresses correctly in ADDRMAP events. (Previously, we had reversed them when the answer was cached.) Fixes bug 5723; bugfix on 0.2.3.1-alpha.
Work correctly on Linux systems with accept4 support advertised in their headers, but without accept4 support in the kernel. Fix by murb. Fixes bug 5762; bugfix on 0.2.3.1-alpha.
When told to add a bridge with the same addr:port as a preexisting bridge but a different transport, change the transport as requested. Previously we would not notice the change. Fixes half of bug 5603; fix on 0.2.3.2-alpha.
Avoid a "double-reply" warning when replying to a SOCKS request with a parse error. Patch from Fabian Keil. Fixes bug 4108; bugfix on 0.2.3.4-alpha.
Fix a bug where a bridge authority crashes if it has seen no directory requests when it's time to write statistics to disk. Fixes bug 5891; bugfix on 0.2.3.6-alpha. Also fixes bug 5508 in a better way.
Don't try to open non-control listeners when DisableNetwork is set. Previousy, we'd open all listeners, then immediately close them. Fixes bug 5604; bugfix on 0.2.3.9-alpha.
Don't abort the managed proxy protocol if the managed proxy sends us an unrecognized line; ignore it instead. Fixes bug 5910; bugfix on 0.2.3.9-alpha.
Fix a compile warning in crypto.c when compiling with clang 3.1. Fixes bug 5969, bugfix on 0.2.3.9-alpha.
Fix a compilation issue on GNU Hurd, which doesn't have PATH_MAX. Fixes bug 5355; bugfix on 0.2.3.11-alpha.
Remove bogus definition of "_WIN32" from src/win32/orconfig.h, to unbreak the MSVC build. Fies bug 5858; bugfix on 0.2.3.12-alpha.
Resolve numerous small warnings and build issues with MSVC. Resolves bug 5859.
Documentation fixes:
Improve the manual's documentation for the NT Service command-line options. Addresses ticket 3964.
Clarify SessionGroup documentation slightly; resolves ticket 5437.
Document the changes to the ORPort and DirPort options, and the fact that {OR/Dir}ListenAddress is now unnecessary (and therefore deprecated). Resolves ticket 5597.
Removed files:
Remove the torrc.bridge file: we don't use it for anything, and it had become badly desynchronized from torrc.sample. Resolves bug 5622.

New in Tor 0.2.2.36 (May 30, 2012)

Tor 0.2.2.36 updates the addresses for twof the eight directory authorities, fixes some potential anonymity and security issues, and fixes several crash bugs.
Tor 0.2.1.x has reached its end-of-life. Those Tor versions have many known flaws, and nobody should be using them. You should upgrade. If you're using a Linux or BSD and its packages are obsolete, stop using those packages and upgrade anyway.
DIRECTORY AUTHORITY CHANGES:
Change IP address for maatuska (v3 directory authority).
Change IP address for ides (v3 directory authority), and rename it tturtles.
SECURITY FIXES:
When building or running with any version of OpenSSL earlier than 0.9.8s or 1.0.0f, disable SSLv3 support. These OpenSSL versions have a bug (CVE-2011-4576) in which their block cipher padding includes uninitialized data, potentially leaking sensitive information tany peer with whom they make a SSLv3 connection. Tor does not use SSL v3 by default, but a hostile client or server could force an SSLv3 connection in order tgain information that they shouldn't have been able tget. The best solution here is tupgrade tOpenSSL 0.9.8s or 1.0.0f (or later). But when building or running with a non-upgraded OpenSSL, we disable SSLv3 entirely tmake sure that the bug can't happen.
Never use a bridge or a controller-supplied node as an exit, even if its exit policy allows it. Found by wanoskarnet. Fixes bug 5342. Bugfix on 0.1.1.15-rc (for controller-purpose descriptors) and 0.2.0.3-alpha (for bridge-purpose descriptors).
Only build circuits if we have a sufficient threshold of the total descriptors that are marked in the consensus with the "Exit" flag. This mitigates an attack proposed by wanoskarnet, in which all of a client's bridges collude trestrict the exit nodes that the client knows about. Fixes bug 5343.
Provide controllers with a safer way timplement the cookie authentication mechanism. With the old method, if another locally running program could convince a controller that it was the Tor process, then that program could trick the contoller inttelling it the contents of an arbitrary 32-byte file. The new "SAFECOOKIE" authentication method uses a challenge-response approach tprevent this attack. Fixes bug 5185; implements proposal 193.
MAJOR BUG FIXES:
Avoid logging uninitialized data when unable tdecode a hidden service descriptor cookie. Fixes bug 5647; bugfix on 0.2.1.5-alpha.
Avoid a client-side assertion failure when receiving an INTRODUCE2 cell on a general purpose circuit. Fixes bug 5644; bugfix on 0.2.1.6-alpha.
Fix builds when the path tsed, openssl, or sha1sum contains spaces, which is pretty common on Windows. Fixes bug 5065; bugfix on 0.2.2.1-alpha.
Correct our replacements for the timeradd() and timersub() functions on platforms that lack them (for example, Windows). The timersub() function is used when expiring circuits, while timeradd() is currently unused. Bug report and patch by Vektor. Fixes bug 4778; bugfix on 0.2.2.24-alpha.
Fix the SOCKET_OK test that we use ttell when socket creation fails sthat it works on Win64. Fixes part of bug 4533; bugfix on 0.2.2.29-beta. Bug found by wanoskarnet.
MINOR BUG FIXES:
Reject out-of-range times like 23:59:61 in parse_rfc1123_time(). Fixes bug 5346; bugfix on 0.0.8pre3.
Make our number-parsing functions always treat too-large values as an error, even when those values exceed the width of the underlying type. Previously, if the caller provided these functions with minima or maxima set tthe extreme values of the underlying integer type, these functions would return those values on overflow rather than treating overflow as an error. Fixes part of bug 5786; bugfix on 0.0.9.
Older Linux kernels erroneously respond tstrange nmap behavior by having accept() return successfully with a zero-length socket. When this happens, just close the connection. Previously, we would try harder tlearn the remote address: but there was nsuch remote address tlearn, and our method for trying tlearn it was incorrect. Fixes bugs 1240, 4745, and 4747. Bugfix on 0.1.0.3-rc. Reported and diagnosed by "r1eo".
Correct parsing of certain date types in parse_http_time(). Without this patch, If-Modified-Since would behave incorrectly. Fixes bug 5346; bugfix on 0.2.0.2-alpha. Patch from Esteban ManchadVelázques.
Change the BridgePassword feature (part of the "bridge community" design, which is not yet implemented) tuse a time-independent comparison. The old behavior might have allowed an adversary tuse timing tguess the BridgePassword value. Fixes bug 5543; bugfix on 0.2.0.14-alpha.
Detect and reject certain misformed escape sequences in configuration values. Previously, these values would cause us tcrash if received in a torrc file or over an authenticated control port. Bug found by Esteban ManchadVelázquez, and independently by Robert Connolly from Matta Consulting whfurther noted that it allows a post-authentication heap overflow. Patch by Alexander Schrijver. Fixes bugs 5090 and 5402 (CVE 2012-1668); bugfix on 0.2.0.16-alpha.
Fix a compile warning when using the --enable-openbsd-malloc configure option. Fixes bug 5340; bugfix on 0.2.0.20-rc.
During configure, detect when we're building with clang version 3.0 or lower and disable the -Wnormalized=id and -Woverride-init CFLAGS. clang doesn't support them yet.
When sending an HTTP/1.1 proxy request, include a Host header. Fixes bug 5593; bugfix on 0.2.2.1-alpha.
Fix a NULL-pointer dereference on a badly formed SETCIRCUITPURPOSE command. Found by mikeyc. Fixes bug 5796; bugfix on 0.2.2.9-alpha.
If we hit the error case where routerlist_insert() replaces an existing (old) server descriptor, make sure tremove that server descriptor from the old_routers list. Fix related tbug 1776. Bugfix on 0.2.2.18-alpha.
MINOR BUG FIXES (DOCUMENTATION AND LOG MESSAGES):
Fix a typin a log message in rend_service_rendezvous_has_opened(). Fixes bug 4856; bugfix on Tor 0.0.6.
Update "ClientOnly" man page entry texplain that there isn't really any point tmessing with it. Resolves ticket 5005.
Document the GiveGuardFlagTo_CVE_2011_2768_VulnerableRelays directory authority option (introduced in Tor 0.2.2.34).
Downgrade the "We're missing a certificate" message from notice tinfo: people kept mistaking it for a real problem, whereas it is seldom the problem even when we are failing tbootstrap. Fixes bug 5067; bugfix on 0.2.0.10-alpha.
Correctly spell "connect" in a log message on failure tcreate a controlsocket. Fixes bug 4803; bugfix on 0.2.2.26-beta.
Clarify the behavior of MaxCircuitDirtiness with hidden service circuits. Fixes issue 5259.
MINOR FEATURES:
Directory authorities now reject versions of Tor older than 0.2.1.30, and Tor versions between 0.2.2.1-alpha and 0.2.2.20-alpha inclusive. These versions accounted for only a small fraction of the Tor network, and have numerous known security issues. Resolves issue 4788.
Update the May 1 2012 Maxmind GeoLite Country database.
FEATURE REMOVAL:
When sending or relaying a RELAY_EARLY cell, we used tconvert it ta RELAY cell if the connection was using the v1 link protocol. This was a workaround for older versions of Tor, which didn't handle RELAY_EARLY cells properly. Now that all supported versions can handle RELAY_EARLY cells, and now that we're enforcing the "nRELAY_EXTEND commands except in RELAY_EARLY cells" rule, remove this workaround. Addresses bug 4786.

New in Tor 0.2.3.14 Alpha (Apr 24, 2012)

Major bugfixes:
Fix a heap overflow bug that could occur when trying to pull data into the first chunk of a buffer, when that chunk had already had some data drained from it. Fixes CVE-2011-2778; bugfix on 0.2.0.16-alpha. Reported by "Vektor".
Initialize Libevent with the EVENT_BASE_FLAG_NOLOCK flag enabled, so that it doesn't attempt to allocate a socketpair. This could cause some problems on Windows systems with overzealous firewalls. Fix for bug 4457; workaround for Libevent versions 2.0.1-alpha through 2.0.15-stable.
If we mark an OR connection for close based on a cell we process, don't process any further cells on it. We already avoid further reads on marked-for-close connections, but now we also discard the cells we'd already read. Fixes bug 4299; bugfix on 0.2.0.10-alpha, which was the first version where we might mark a connection for close based on processing a cell on it.
Correctly sanity-check that we don't underflow on a memory allocation (and then assert) for hidden service introduction point decryption. Bug discovered by Dan Rosenberg. Fixes bug 4410; bugfix on 0.2.1.5-alpha.
Fix a memory leak when we check whether a hidden service descriptor has any usable introduction points left. Fixes bug 4424. Bugfix on 0.2.2.25-alpha.
Don't crash when we're running as a relay and don't have a GeoIP file. Bugfix on 0.2.2.34; fixes bug 4340. This backports a fix we've had in the 0.2.3.x branch already.
When running as a client, do not print a misleading (and plain wrong) log message that we're collecting "directory request" statistics: clients don't collect statistics. Also don't create a useless (because empty) stats file in the stats/ directory. Fixes bug 4353; bugfix on 0.2.2.34.
Minor bugfixes:
Detect failure to initialize Libevent. This fix provides better detection for future instances of bug 4457.
Avoid frequent calls to the fairly expensive cull_wedged_cpuworkers function. This was eating up hideously large amounts of time on some busy servers. Fixes bug 4518; bugfix on 0.0.9.8.
Resolve an integer overflow bug in smartlist_ensure_capacity(). Fixes bug 4230; bugfix on Tor 0.1.0.1-rc. Based on a patch by Mansour Moufid.
Don't warn about unused log_mutex in log.c when building with --disable-threads using a recent GCC. Fixes bug 4437; bugfix on 0.1.0.6-rc which introduced --disable-threads.
When configuring, starting, or stopping an NT service, stop immediately after the service configuration attempt has succeeded or failed. Fixes bug 3963; bugfix on 0.2.0.7-alpha.
When sending a NETINFO cell, include the original address received for the other side, not its canonical address. Found by "troll_un"; fixes bug 4349; bugfix on 0.2.0.10-alpha.
Fix a typo in a hibernation-related log message. Fixes bug 4331; bugfix on 0.2.2.23-alpha; found by "tmpname0901".
Fix a memory leak in launch_direct_bridge_descriptor_fetch() that occurred when a client tried to fetch a descriptor for a bridge in ExcludeNodes. Fixes bug 4383; bugfix on 0.2.2.25-alpha.
Backport fixes for a pair of compilation warnings on Windows. Fixes bug 4521; bugfix on 0.2.2.28-beta and on 0.2.2.29-beta.
If we had ever tried to call tor_addr_to_str on an address of unknown type, we would have done a strdup on an uninitialized buffer. Now we won't. Fixes bug 4529; bugfix on 0.2.1.3-alpha. Reported by "troll_un".
Correctly detect and handle transient lookup failures from tor_addr_lookup. Fixes bug 4530; bugfix on 0.2.1.5-alpha. Reported by "troll_un".
Fix null-pointer access that could occur if TLS allocation failed. Fixes bug 4531; bugfix on 0.2.0.20-rc. Found by "troll_un".
Use tor_socket_t type for listener argument to accept(). Fixes bug 4535; bugfix on 0.2.2.28-beta. Found by "troll_un".
Minor features:
Add two new config options for directory authorities: AuthDirFastGuarantee sets a bandwidth threshold for guaranteeing the Fast flag, and AuthDirGuardBWGuarantee sets a bandwidth threshold that is always sufficient to satisfy the bandwidth requirement for the Guard flag. Now it will be easier for researchers to simulate Tor networks with different values. Resolves ticket 4484.
When Tor ignores a hidden service specified in its configuration, include the hidden service's directory in the warning message. Previously, we would only tell the user that some hidden service was ignored. Bugfix on 0.0.6; fixes bug 4426.
Update to the December 6 2011 Maxmind GeoLite Country database.
Packaging changes:
Make it easier to automate expert package builds on Windows, by removing an absolute path from makensis.exe command.

New in Tor 0.2.3.12 Alpha (Mar 27, 2012)

Directory authority changes:
Change IP address for maatuska (v3 directory authority).
Security fixes:
Provide controllers with a safer way to implement the cookie authentication mechanism. With the old method, if another locally running program could convince a controller that it was the Tor process, then that program could trick the contoller into telling it the contents of an arbitrary 32-byte file. The new "SAFECOOKIE" authentication method uses a challenge-response approach to prevent this attack. Fixes bug 5185, implements proposal 193.
Never use a bridge or a controller-supplied node as an exit, even if its exit policy allows it. Found by wanoskarnet. Fixes bug 5342. Bugfix on 0.1.1.15-rc (for controller-purpose descriptors) and 0.2.0.3-alpha (for bridge-purpose descriptors).
Only build circuits if we have a sufficient threshold of the total descriptors that are marked in the consensus with the "Exit" flag. This mitigates an attack proposed by wanoskarnet, in which all of a client's bridges collude to restrict the exit nodes that the client knows about. Fixes bug 5343.
Major bugfixes (on Tor 0.2.3.x):
Avoid an assert when managed proxies like obfsproxy are configured, and we receive HUP signals or setconf attempts too rapidly. This situation happens most commonly when Vidalia tries to attach to Tor or tries to configure the Tor it's attached to. Fixes bug 5084; bugfix on 0.2.3.6-alpha.
Fix a relay-side pluggable transports bug where managed proxies were unreachable from the Internet, because Tor asked them to bind on localhost. Fixes bug 4725; bugfix on 0.2.3.9-alpha.
Stop discarding command-line arguments when TestingTorNetwork is set. Discovered by Kevin Bauer. Fixes bug 5373; bugfix on 0.2.3.9-alpha, where task 4552 added support for two layers of torrc files.
Resume allowing the unit tests to run in gdb. This was accidentally made impossible when the DisableDebuggerAttachment option was introduced. Fixes bug 5448; bugfix on 0.2.3.9-alpha.
Resume building with nat-pmp support. Fixes bug 4955; bugfix on 0.2.3.11-alpha. Reported by Anthony G. Basile.
Minor bugfixes (on 0.2.2.x and earlier):
Ensure we don't cannibalize circuits that are longer than three hops already, so we don't end up making circuits with 5 or more hops. Patch contributed by wanoskarnet. Fixes bug 5231; bugfix on 0.1.0.1-rc which introduced cannibalization.
Detect and reject certain misformed escape sequences in configuration values. Previously, these values would cause us to crash if received in a torrc file or over an authenticated control port. Bug found by Esteban Manchado Velázquez, and independently by Robert Connolly from Matta Consulting who further noted that it allows a post-authentication heap overflow. Patch by Alexander Schrijver. Fixes bugs 5090 and 5402 (CVE 2012-1668); bugfix on 0.2.0.16-alpha.
Fix a compile warning when using the --enable-openbsd-malloc configure option. Fixes bug 5340; bugfix on 0.2.0.20-rc.
Directory caches no longer refuse to clean out descriptors because of missing v2 networkstatus documents, unless they're configured to retrieve v2 networkstatus documents. Fixes bug 4838; bugfix on 0.2.2.26-beta. Patch by Daniel Bryg.
Update to the latest version of the tinytest unit testing framework. This includes a couple of bugfixes that can be relevant for running forked unit tests on Windows, and removes all reserved identifiers.
Minor bugfixes (on 0.2.3.x):
On a failed pipe() call, don't leak file descriptors. Fixes bug 4296; bugfix on 0.2.3.1-alpha.
Spec conformance: on a v3 handshake, do not send a NETINFO cell until after we have received a CERTS cell. Fixes bug 4361; bugfix on 0.2.3.6-alpha. Patch by "frosty".
When binding to an IPv6 address, set the IPV6_V6ONLY socket option, so that the IP stack doesn't decide to use it for IPv4 too. Fixes bug 4760; bugfix on 0.2.3.9-alpha.
Ensure that variables set in Tor's environment cannot override environment variables that Tor passes to a managed pluggable-transport proxy. Previously, Tor would pass every variable in its environment to managed proxies along with the new ones, in such a way that on many operating systems, the inherited environment variables would override those which Tor tried to explicitly set. Bugfix on 0.2.3.12-alpha for most Unixoid systems; bugfix on 0.2.3.9-alpha for Windows.
Minor features:
A wide variety of new unit tests by Esteban Manchado Velázquez.
Shorten links in the tor-exit-notice file. Patch by Christian Kujau.
Update to the March 6 2012 Maxmind GeoLite Country database.

New in Tor 0.2.3.12 Alpha (Feb 15, 2012)

Major bugfixes:
Fix builds when the path to sed, openssl, or sha1sum contains spaces, which is pretty common on Windows. Fixes bug 5065; bugfix on 0.2.2.1-alpha.
Set the SO_REUSEADDR socket option before we call bind() on outgoing connections. This change should allow busy exit relays to stop running out of available sockets as quickly. Fixes bug 4950; bugfix on 0.2.2.26-beta.
Allow 0.2.3.x clients to use 0.2.2.x bridges. Previously the client would ask the bridge for microdescriptors, which are only supported in 0.2.3.x, and then fail to bootstrap when it didn't get the answers it wanted. Fixes bug 4013; bugfix on 0.2.3.2-alpha.
Avoid an assert when managed proxies like obfsproxy are configured, and we receive HUP signals or configuration values too rapidly. This situation happens most commonly when Vidalia tries to attach to Tor or tries to configure the Tor it's attached to. Fixes bug 5084; bugfix on 0.2.3.6-alpha.
Properly set up obfsproxy's environment when in managed mode. The Tor Browser Bundle needs LD_LIBRARY_PATH to be passed to obfsproxy, and when you run your Tor as a daemon, there's no HOME. Fixes bugs 5076 and 5082; bugfix on 0.2.3.6-alpha.
Minor features:
Use the dead_strip option when building Tor on OS X. This reduces binary size by almost 19% when linking openssl and libevent statically, which we do for Tor Browser Bundle.
Fix broken URLs in the sample torrc file, and tell readers about the OutboundBindAddress, ExitPolicyRejectPrivate, and PublishServerDescriptor options. Addresses bug 4652.
Update to the February 7 2012 Maxmind GeoLite Country database.
Minor bugfixes:
Downgrade the "We're missing a certificate" message from notice to info: people kept mistaking it for a real problem, whereas it is seldom the problem even when we are failing to bootstrap. Fixes bug 5067; bugfix on 0.2.0.10-alpha.
Don't put "TOR_PT_EXTENDED_SERVER_PORT=127.0.0.1:4200" in a managed pluggable transport server proxy's environment. Previously, we would put it there, even though Tor doesn't implement an 'extended server port' yet, and even though Tor almost certainly isn't listening at that address. For now, we set it to an empty string to avoid crashing older obfsproxies. Bugfix on 0.2.3.6-alpha.
Log the heartbeat message every HeartbeatPeriod seconds, not every HeartbeatPeriod + 1 seconds. Fixes bug 4942; bugfix on 0.2.3.1-alpha. Bug reported by Scott Bennett.
Calculate absolute paths correctly on Windows. Fixes bug 4973; bugfix on 0.2.3.11-alpha.
Update "ClientOnly" man page entry to explain that there isn't really any point to messing with it. Resolves ticket 5005.
Use the correct CVE number for CVE-2011-4576 in our comments and log messages. Found by "fermenthor". Resolves bug 5066; bugfix on 0.2.3.11-alpha.
Code simplifications and refactoring:
Use the _WIN32 macro throughout our code to detect Windows. (Previously we had used the obsolete 'WIN32' and the idiosyncratic 'MS_WINDOWS'.)

New in Tor 0.2.3.10 Alpha (Dec 17, 2011)

New in Tor 0.2.2.35 (Dec 17, 2011)

Major bugfixes:
Fix a heap overflow bug that could occur when trying to pull data into the first chunk of a buffer, when that chunk had already had some data drained from it. Fixes CVE-2011-2778; bugfix on 0.2.0.16-alpha. Reported by "Vektor".
Initialize Libevent with the EVENT_BASE_FLAG_NOLOCK flag enabled, so that it doesn't attempt to allocate a socketpair. This could cause some problems on Windows systems with overzealous firewalls. Fix for bug 4457; workaround for Libevent versions 2.0.1-alpha through 2.0.15-stable.
If we mark an OR connection for close based on a cell we process, don't process any further cells on it. We already avoid further reads on marked-for-close connections, but now we also discard the cells we'd already read. Fixes bug 4299; bugfix on 0.2.0.10-alpha, which was the first version where we might mark a connection for close based on processing a cell on it.
Correctly sanity-check that we don't underflow on a memory allocation (and then assert) for hidden service introduction point decryption. Bug discovered by Dan Rosenberg. Fixes bug 4410; bugfix on 0.2.1.5-alpha.
Fix a memory leak when we check whether a hidden service descriptor has any usable introduction points left. Fixes bug 4424. Bugfix on 0.2.2.25-alpha.
Don't crash when we're running as a relay and don't have a GeoIP file. Bugfix on 0.2.2.34; fixes bug 4340. This backports a fix we've had in the 0.2.3.x branch already.
When running as a client, do not print a misleading (and plain wrong) log message that we're collecting "directory request" statistics: clients don't collect statistics. Also don't create a useless (because empty) stats file in the stats/ directory. Fixes bug 4353; bugfix on 0.2.2.34.
Minor bugfixes:
Detect failure to initialize Libevent. This fix provides better detection for future instances of bug 4457.
Avoid frequent calls to the fairly expensive cull_wedged_cpuworkers function. This was eating up hideously large amounts of time on some busy servers. Fixes bug 4518; bugfix on 0.0.9.8.
Resolve an integer overflow bug in smartlist_ensure_capacity(). Fixes bug 4230; bugfix on Tor 0.1.0.1-rc. Based on a patch by Mansour Moufid.
Don't warn about unused log_mutex in log.c when building with --disable-threads using a recent GCC. Fixes bug 4437; bugfix on 0.1.0.6-rc which introduced --disable-threads.
When configuring, starting, or stopping an NT service, stop immediately after the service configuration attempt has succeeded or failed. Fixes bug 3963; bugfix on 0.2.0.7-alpha.
When sending a NETINFO cell, include the original address received for the other side, not its canonical address. Found by "troll_un"; fixes bug 4349; bugfix on 0.2.0.10-alpha.
Fix a typo in a hibernation-related log message. Fixes bug 4331; bugfix on 0.2.2.23-alpha; found by "tmpname0901".
Fix a memory leak in launch_direct_bridge_descriptor_fetch() that occurred when a client tried to fetch a descriptor for a bridge in ExcludeNodes. Fixes bug 4383; bugfix on 0.2.2.25-alpha.
Backport fixes for a pair of compilation warnings on Windows. Fixes bug 4521; bugfix on 0.2.2.28-beta and on 0.2.2.29-beta.
If we had ever tried to call tor_addr_to_str on an address of unknown type, we would have done a strdup on an uninitialized buffer. Now we won't. Fixes bug 4529; bugfix on 0.2.1.3-alpha. Reported by "troll_un".
Correctly detect and handle transient lookup failures from tor_addr_lookup. Fixes bug 4530; bugfix on 0.2.1.5-alpha. Reported by "troll_un".
Fix null-pointer access that could occur if TLS allocation failed. Fixes bug 4531; bugfix on 0.2.0.20-rc. Found by "troll_un".
Use tor_socket_t type for listener argument to accept(). Fixes bug 4535; bugfix on 0.2.2.28-beta. Found by "troll_un".
Minor features:
Add two new config options for directory authorities: AuthDirFastGuarantee sets a bandwidth threshold for guaranteeing the Fast flag, and AuthDirGuardBWGuarantee sets a bandwidth threshold that is always sufficient to satisfy the bandwidth requirement for the Guard flag. Now it will be easier for researchers to simulate Tor networks with different values. Resolves ticket 4484.
When Tor ignores a hidden service specified in its configuration, include the hidden service's directory in the warning message. Previously, we would only tell the user that some hidden service was ignored. Bugfix on 0.0.6; fixes bug 4426.
Update to the December 6 2011 Maxmind GeoLite Country database.
Packaging changes:
Make it easier to automate expert package builds on Windows, by removing an absolute path from makensis.exe command.

New in Tor 0.2.3.9 Alpha (Dec 16, 2011)

Major features:
Clients can now connect to private bridges over IPv6. Bridges still need at least one IPv4 address in order to connect to other relays. Note that we don't yet handle the case where the user has two bridge lines for the same bridge (one IPv4, one IPv6). Implements parts of proposal 186.
New "DisableNetwork" config option to prevent Tor from launching any connections or accepting any connections except on a control port. Bundles and controllers can set this option before letting Tor talk to the rest of the network, for example to prevent any connections to a non-bridge address. Packages like Orbot can also use this option to instruct Tor to save power when the network is off.
Clients and bridges can now be configured to use a separate "transport" proxy. This approach makes the censorship arms race easier by allowing bridges to use protocol obfuscation plugins. It implements the "managed proxy" part of proposal 180 (ticket 3472).
When using OpenSSL 1.0.0 or later, use OpenSSL's counter mode implementation. It makes AES_CTR about 7% faster than our old one (which was about 10% faster than the one OpenSSL used to provide). Resolves ticket 4526.
Add a "tor2web mode" for clients that want to connect to hidden services non-anonymously (and possibly more quickly). As a safety measure to try to keep users from turning this on without knowing what they are doing, tor2web mode must be explicitly enabled at compile time, and a copy of Tor compiled to run in tor2web mode cannot be used as a normal Tor client. Implements feature 2553.
Add experimental support for running on Windows with IOCP and no kernel-space socket buffers. This feature is controlled by a new "UserspaceIOCPBuffers" config option (off by default), which has no effect unless Tor has been built with support for bufferevents, is running on Windows, and has enabled IOCP. This may, in the long run, help solve or mitigate bug 98.
Use a more secure consensus parameter voting algorithm. Now at least three directory authorities or a majority of them must vote on a given parameter before it will be included in the consensus. Implements proposal 178.
Major bugfixes:
Hidden services now ignore the timestamps on INTRODUCE2 cells. They used to check that the timestamp was within 30 minutes of their system clock, so they could cap the size of their replay-detection cache, but that approach unnecessarily refused service to clients with wrong clocks. Bugfix on 0.2.1.6-alpha, when the v3 intro-point protocol (the first one which sent a timestamp field in the INTRODUCE2 cell) was introduced; fixes bug 3460.
Only use the EVP interface when AES acceleration is enabled, to avoid a 5-7% performance regression. Resolves issue 4525; bugfix on 0.2.3.8-alpha.
Privacy/anonymity features (bridge detection):
Make bridge SSL certificates a bit more stealthy by using random serial numbers, in the same fashion as OpenSSL when generating self-signed certificates. Implements ticket 4584.
Introduce a new config option "DynamicDHGroups", enabled by default, which provides each bridge with a unique prime DH modulus to be used during SSL handshakes. This option attempts to help against censors who might use the Apache DH modulus as a static identifier for bridges. Addresses ticket 4548.
Minor features (new/different config options):
New configuration option "DisableDebuggerAttachment" (on by default) to prevent basic debugging attachment attempts by other processes. Supports Mac OS X and Gnu/Linux. Resolves ticket 3313.
Allow MapAddress directives to specify matches against super-domains, as in "MapAddress *.torproject.org *.torproject.org.torserver.exit". Implements issue 933.
Slightly change behavior of "list" options (that is, config options that can appear more than once) when they appear both in torrc and on the command line. Previously, the command-line options would be appended to the ones from torrc. Now, the command-line options override the torrc options entirely. This new behavior allows the user to override list options (like exit policies and ports to listen on) from the command line, rather than simply appending to the list.
You can get the old (appending) command-line behavior for "list" options by prefixing the option name with a "+".
You can remove all the values for a "list" option from the command line without adding any new ones by prefixing the option name with a "/".
Add experimental support for a "defaults" torrc file to be parsed before the regular torrc. Torrc options override the defaults file's options in the same way that the command line overrides the torrc.
The SAVECONF controller command saves only those options which differ between the current configuration and the defaults file. HUP reloads both files. (Note: This is an experimental feature; its behavior will probably be refined in future 0.2.3.x-alpha versions to better meet packagers' needs.)
Minor features:
Try to make the introductory warning message that Tor prints on startup more useful for actually finding help and information. Resolves ticket 2474.
Running "make version" now displays the version of Tor that we're about to build. Idea from katmagic; resolves issue 4400.
Expire old or over-used hidden service introduction points. Required by fix for bug 3460.
Move the replay-detection cache for the RSA-encrypted parts of INTRODUCE2 cells to the introduction point data structures. Previously, we would use one replay-detection cache per hidden service. Required by fix for bug 3460.
Reduce the lifetime of elements of hidden services' Diffie-Hellman public key replay-detection cache from 60 minutes to 5 minutes. This replay-detection cache is now used only to detect multiple INTRODUCE2 cells specifying the same rendezvous point, so we can avoid launching multiple simultaneous attempts to connect to it.
Minor bugfixes (on Tor 0.2.2.x and earlier):
Resolve an integer overflow bug in smartlist_ensure_capacity(). Fixes bug 4230; bugfix on Tor 0.1.0.1-rc. Based on a patch by Mansour Moufid.
Fix a minor formatting issue in one of tor-gencert's error messages. Fixes bug 4574.
Prevent a false positive from the check-spaces script, by disabling the "whitespace between function name and (" check for functions named 'op()'.
Fix a log message suggesting that people contact a non-existent email address. Fixes bug 3448.
Fix null-pointer access that could occur if TLS allocation failed. Fixes bug 4531; bugfix on 0.2.0.20-rc. Found by "troll_un".
Report a real bootstrap problem to the controller on router identity mismatch. Previously we just said "foo", which probably made a lot of sense at the time. Fixes bug 4169; bugfix on 0.2.1.1-alpha.
If we had ever tried to call tor_addr_to_str() on an address of unknown type, we would have done a strdup() on an uninitialized buffer. Now we won't. Fixes bug 4529; bugfix on 0.2.1.3-alpha. Reported by "troll_un".
Correctly detect and handle transient lookup failures from tor_addr_lookup(). Fixes bug 4530; bugfix on 0.2.1.5-alpha. Reported by "troll_un".
Use tor_socket_t type for listener argument to accept(). Fixes bug 4535; bugfix on 0.2.2.28-beta. Found by "troll_un".
Initialize conn->addr to a valid state in spawn_cpuworker(). Fixes bug 4532; found by "troll_un".
Minor bugfixes (on Tor 0.2.3.x):
Fix a compile warning in tor_inet_pton(). Bugfix on 0.2.3.8-alpha; fixes bug 4554.
Don't send two ESTABLISH_RENDEZVOUS cells when opening a new circuit for use as a hidden service client's rendezvous point. Fixes bugs 4641 and 4171; bugfix on 0.2.3.3-alpha. Diagnosed with help from wanoskarnet.
Restore behavior of overriding SocksPort, ORPort, and similar options from the command line. Bugfix on 0.2.3.3-alpha.
Build fixes:
Properly handle the case where the build-tree is not the same as the source tree when generating src/common/common_sha1.i, src/or/micro-revision.i, and src/or/or_sha1.i. Fixes bug 3953; bugfix on 0.2.0.1-alpha.
Code simplifications, cleanups, and refactorings:
Remove the pure attribute from all functions that used it previously. In many cases we assigned it incorrectly, because the functions might assert or call impure functions, and we don't have evidence that keeping the pure attribute is worthwhile. Implements changes suggested in ticket 4421.
Remove some dead code spotted by coverity. Fixes cid 432. Bugfix on 0.2.3.1-alpha, closes bug 4637.

New in Tor 0.2.3.8 Alpha (Nov 26, 2011)

Tor 0.2.3.8-alpha fixes some crash and assert bugs, including a socketpair-related bug that has been bothering Windows users. It adds support to serve microdescriptors to controllers, so Vidalia's network map can resume listing relays (once Vidalia implements its side), and adds better support for hardware AES acceleration. Finally, it starts the process of adjusting the bandwidth cutoff for getting the "Fast" flag from 20KB to (currently) 32KB -- preliminary results show that tiny relays harm performance more than they help network capacity.
Major bugfixes:
Initialize Libevent with the EVENT_BASE_FLAG_NOLOCK flag enabled, so that it doesn't attempt to allocate a socketpair. This could cause some problems on Windows systems with overzealous firewalls. Fix for bug 4457; workaround for Libevent versions 2.0.1-alpha through 2.0.15-stable.
Correctly sanity-check that we don't underflow on a memory allocation (and then assert) for hidden service introduction point decryption. Bug discovered by Dan Rosenberg. Fixes bug 4410; bugfix on 0.2.1.5-alpha.
Remove the artificially low cutoff of 20KB to guarantee the Fast flag. In the past few years the average relay speed has picked up, and while the "top 7/8 of the network get the Fast flag" and "all relays with 20KB or more of capacity get the Fast flag" rules used to have the same result, now the top 7/8 of the network has a capacity more like 32KB. Bugfix on 0.2.1.14-rc. Fixes bug 4489.
Fix a rare assertion failure when checking whether a v0 hidden service descriptor has any usable introduction points left, and we don't have enough information to build a circuit to the first intro point named in the descriptor. The HS client code in 0.2.3.x no longer uses v0 HS descriptors, but this assertion can trigger on (and crash) v0 HS authorities. Fixes bug 4411. Bugfix on 0.2.3.1-alpha; diagnosed by frosty_un.
Make bridge authorities not crash when they are asked for their own descriptor. Bugfix on 0.2.3.7-alpha, reported by Lucky Green.
When running as a client, do not print a misleading (and plain wrong) log message that we're collecting "directory request" statistics: clients don't collect statistics. Also don't create a useless (because empty) stats file in the stats/ directory. Fixes bug 4353; bugfix on 0.2.2.34 and 0.2.3.7-alpha.
Major features:
Allow Tor controllers like Vidalia to obtain the microdescriptor for a relay by identity digest or nickname. Previously, microdescriptors were only available by their own digests, so a controller would have to ask for and parse the whole microdescriptor consensus in order to look up a single relay's microdesc. Fixes bug 3832; bugfix on 0.2.3.1-alpha.
Use OpenSSL's EVP interface for AES encryption, so that all AES operations can use hardware acceleration (if present). Resolves ticket 4442.
Minor bugfixes (on 0.2.2.x and earlier):
Detect failure to initialize Libevent. This fix provides better detection for future instances of bug 4457.
Avoid frequent calls to the fairly expensive cull_wedged_cpuworkers function. This was eating up hideously large amounts of time on some busy servers. Fixes bug 4518; bugfix on 0.0.9.8.
Don't warn about unused log_mutex in log.c when building with --disable-threads using a recent GCC. Fixes bug 4437; bugfix on 0.1.0.6-rc which introduced --disable-threads.
Allow manual 'authenticate' commands to the controller interface from netcat (nc) as well as telnet. We were rejecting them because they didn't come with the expected whitespace at the end of the command. Bugfix on 0.1.1.1-alpha; fixes bug 2893.
Fix some (not actually triggerable) buffer size checks in usage of tor_inet_ntop. Fixes bug 4434; bugfix on Tor 0.2.0.1-alpha. Patch by Anders Sundman.
Fix parsing of some corner-cases with tor_inet_pton(). Fixes bug 4515; bugfix on 0.2.0.1-alpha; fix by Anders Sundman.
When configuring, starting, or stopping an NT service, stop immediately after the service configuration attempt has succeeded or failed. Fixes bug 3963; bugfix on 0.2.0.7-alpha.
When sending a NETINFO cell, include the original address received for the other side, not its canonical address. Found by "troll_un"; fixes bug 4349; bugfix on 0.2.0.10-alpha.
Rename the bench_{aes,dmap} functions to test_*, so that tinytest can pick them up when the tests aren't disabled. Bugfix on 0.2.2.4-alpha which introduced tinytest.
Fix a memory leak when we check whether a hidden service descriptor has any usable introduction points left. Fixes bug 4424. Bugfix on 0.2.2.25-alpha.
Fix a memory leak in launch_direct_bridge_descriptor_fetch() that occurred when a client tried to fetch a descriptor for a bridge in ExcludeNodes. Fixes bug 4383; bugfix on 0.2.2.25-alpha.
Minor bugfixes (on 0.2.3.x):
Make util unit tests build correctly with MSVC. Bugfix on 0.2.3.3-alpha. Patch by Gisle Vanem.
Successfully detect AUTH_CHALLENGE cells with no recognized authentication type listed. Fixes bug 4367; bugfix on 0.2.3.6-alpha. Found by frosty_un.
If a relay receives an AUTH_CHALLENGE cell it can't answer, it should still send a NETINFO cell to allow the connection to become open. Fixes bug 4368; fix on 0.2.3.6-alpha; bug found by "frosty".
Log less loudly when we get an invalid authentication certificate from a source other than a directory authority: it's not unusual to see invalid certs because of clock skew. Fixes bug 4370; bugfix on 0.2.3.6-alpha.
Tolerate servers with more clock skew in their authentication certificates than previously. Fixes bug 4371; bugfix on 0.2.3.6-alpha.
Fix a couple of compile warnings on Windows. Fixes bug 4469; bugfix on 0.2.3.4-alpha and 0.2.3.6-alpha.
Minor features:
Add two new config options for directory authorities: AuthDirFastGuarantee sets a bandwidth threshold for guaranteeing the Fast flag, and AuthDirGuardBWGuarantee sets a bandwidth threshold that is always sufficient to satisfy the bandwidth requirement for the Guard flag. Now it will be easier for researchers to simulate Tor networks with different values. Resolves ticket 4484.
When Tor ignores a hidden service specified in its configuration, include the hidden service's directory in the warning message. Previously, we would only tell the user that some hidden service was ignored. Bugfix on 0.0.6; fixes bug 4426.
When we fail to initialize Libevent, retry with IOCP disabled so we don't need to turn on multi-threading support in Libevent, which in turn requires a working socketpair(). This is a workaround for bug 4457, which affects Libevent versions from 2.0.1-alpha through 2.0.15-stable.
Detect when we try to build on a platform that doesn't define AF_UNSPEC to 0. We don't work there, so refuse to compile.
Update to the November 1 2011 Maxmind GeoLite Country database.
Packaging changes:
Make it easier to automate expert package builds on Windows, by removing an absolute path from makensis.exe command.
Code simplifications and refactoring:
Remove some redundant #include directives throughout the code. Patch from Andrea Gelmini.
Unconditionally use OpenSSL's AES implementation instead of our old built-in one. OpenSSL's AES has been better for a while, and relatively few servers should still be on any version of OpenSSL that doesn't have good optimized assembly AES.
Use the name "CERTS" consistently to refer to the new cell type; we were calling it CERT in some places and CERTS in others.
Testing:
Numerous new unit tests for functions in util.c and address.c by Anders Sundman.
The long-disabled benchmark tests are now split into their own ./src/test/bench binary.
The benchmark tests can now use more accurate timers than gettimeofday() when such timers are available.

New in Tor 0.2.2.33 (Sep 21, 2011)

Major bugfixes:
Avoid an assertion failure when reloading a configuration withTrackExitHosts changes. Found and fixed by 'laruldan'. Fixes bug3923; bugfix on 0.2.2.25-alpha.
Minor features (security):
Check for replays of the public-key encrypted portion of anINTRODUCE1 cell, in addition to the current check for replays ofthe g^x value. This prevents a possible class of active attacksby an attacker who controls both an introduction point and arendezvous point, and who uses the malleability of AES-CTR toalter the encrypted g^x portion of the INTRODUCE1 cell. We thinkthat these attacks are infeasible (requiring the attacker to sendon the order of zettabytes of altered cells in a short interval),but we'd rather block them off in case there are any classes ofthis attack that we missed. Reported by Willem Pinckaers.
Minor features:
Adjust the expiration time on our SSL session certificates tobetter match SSL certs seen in the wild. Resolves ticket 4014.
Change the default required uptime for a relay to be accepted asa HSDir (hidden service directory) from 24 hours to 25 hours.Improves on 0.2.0.10-alpha; resolves ticket 2649.
Add a VoteOnHidServDirectoriesV2 config option to allow directoryauthorities to abstain from voting on assignment of the HSDirconsensus flag. Related to bug 2649.
Update to the September 6 2011 Maxmind GeoLite Country database.
Minor bugfixes (documentation and log messages):
Correct the man page to explain that HashedControlPassword andCookieAuthentication can both be set, in which case either methodis sufficient to authenticate to Tor. Bugfix on 0.2.0.7-alpha,when we decided to allow these config options to both be set. Issueraised by bug 3898.
Demote the 'replay detected' log message emitted when a hiddenservice receives the same Diffie-Hellman public key in two differentINTRODUCE2 cells to info level. A normal Tor client can cause thatlog message during its normal operation. Bugfix on 0.2.1.6-alpha;fixes part of bug 2442.
Demote the 'INTRODUCE2 cell is too {old,new}' log message to infolevel. There is nothing that a hidden service's operator can doto fix its clients' clocks. Bugfix on 0.2.1.6-alpha; fixes partof bug 2442.
Clarify a log message specifying the characters permitted inHiddenServiceAuthorizeClient client names. Previously, the logmessage said that "[A-Za-z0-9+-_]" were permitted; that could havegiven the impression that every ASCII character between "+" and "_"was permitted. Now we say "[A-Za-z0-9+_-]". Bugfix on 0.2.1.5-alpha.
Build fixes:
Provide a substitute implementation of lround() for MSVC, whichapparently lacks it. Patch from Gisle Vanem.
Clean up some code issues that prevented Tor from building on olderBSDs. Fixes bug 3894; reported by "grarpamp".
Search for a platform-specific version of "ar" when cross-compiling.Should fix builds on iOS. Resolves bug 3909, found by Marco Bonetti.

New in Tor 0.2.2.32 (Sep 1, 2011)

New in Tor 0.2.2.21 Alpha (Jan 18, 2011)

Major bugfixes (security), alsincluded in 0.2.1.29:
Fix a heap overflow bug where an adversary could cause heap corruption. This bug probably allows remote code execution attacks. Reported by "debuger". Fixes CVE-2011-0427. Bugfix on 0.1.2.10-rc.
Prevent a denial-of-service attack by disallowing any zlib-compressed data whose compression factor is implausibly high. Fixes part of bug 2324; reported by "doorss".
Zerout a few more keys in memory before freeing them. Fixes bug 2384 and part of bug 2385. These key instances found by "cypherpunks", based on Andrew Case's report about being able tfind sensitive data in Tor's memory space if you have enough permissions. Bugfix on 0.0.2pre9.
Major bugfixes (crashes), alsincluded in 0.2.1.29:
Prevent calls tLibevent from inside Libevent log handlers. This had potential tcause a nasty set of crashes, especially if running Libevent with debug logging enabled, and running Tor with a controller watching for low-severity log messages. Bugfix on 0.1.0.2-rc. Fixes bug 2190.
Add a check for SIZE_T_MAX ttor_realloc() ttry tavoid underflow errors there too. Fixes the other part of bug 2324.
Fix a bug where we would assert if we ever had a cached-descriptors.new file (or another file read directly intmemory) of exactly SIZE_T_CEILING bytes. Fixes bug 2326; bugfix on 0.2.1.25. Found by doorss.
Fix some potential asserts and parsing issues with grossly malformed router caches. Fixes bug 2352; bugfix on Tor 0.2.1.27. Found by doorss.
Minor bugfixes (other), alsincluded in 0.2.1.29:
Fix a bug with handling misformed replies treverse DNS lookup requests in DNSPort. Bugfix on Tor 0.2.0.1-alpha. Related ta bug reported by doorss.
Fix compilation on mingw when a pthreads compatibility library has been installed. (We don't want tuse it, swe shouldn't be including pthread.h.) Fixes bug 2313; bugfix on 0.1.0.1-rc.
Fix a bug where we would declare that we had run out of virtual addresses when the address space was only half-exhausted. Bugfix on 0.1.2.1-alpha.
Correctly handle the case where AutomapHostsOnResolve is set but nvirtual addresses are available. Fixes bug 2328; bugfix on 0.1.2.1-alpha. Bug found by doorss.
Correctly handle wrapping around twhen we run out of virtual address space. Found by cypherpunks, bugfix on 0.2.0.5-alpha.
The 0.2.1.28 tarball was missing src/common/OpenBSD_malloc_Linux.c because we built it with a too-old version of automake. Thus that release broke ./configure --enable-openbsd-malloc, which is popular among really fast exit relays on Linux.
Minor features, alsincluded in 0.2.1.29:
Update tthe January 1 2011 Maxmind GeoLite Country database.
Introduce output size checks on all of our decryption functions.
Build changes, alsincluded in 0.2.1.29:
Tor does not build packages correctly with Automake 1.6 and earlier; added a check tMakefile.am tmake sure that we're building with Automake 1.7 or later.
Major bugfixes, new in 0.2.2.21-alpha:
Prevent crash/heap corruption when the cbtnummodes consensus parameter is set t0 or large values. Fixes bug 2317; bugfix on 0.2.2.14-alpha.
Major features, new in 0.2.2.21-alpha:
Introduce minimum/maximum values that clients will believe from the consensus. Now we'll have a better chance tavoid crashes or worse when a consensus param has a weird value.
Minor features, new in 0.2.2.21-alpha:
Make sure tdisable DirPort if running as a bridge. DirPorts aren't used on bridges, and it makes bridge scanning somewhat easier.
If writing the state file tdisk fails, wait up tan hour before retrying again, rather than trying again each second. Fixes bug 2346; bugfix on Tor 0.1.1.3-alpha.
Make Libevent log messages get delivered tcontrollers later, and not from inside the Libevent log handler. This prevents unsafe reentrant Libevent calls while still letting the log messages get through.
Detect platforms that brokenly use a signed size_t, and refuse tbuild there. Found and analyzed by doorss and rransom.
Fix a bunch of compile warnings revealed by mingw with gcc 4.5. Resolves bug 2314.
Minor bugfixes, new in 0.2.2.21-alpha:
Handle SOCKS messages longer than 128 bytes long correctly, rather than waiting forever for them tfinish. Fixes bug 2330; bugfix on 0.2.0.16-alpha. Found by doorss.
Add assertions tcheck for overflow in arguments tbase32_encode() and base32_decode(); fix a signed-unsigned comparison there too. These bugs are not actually reachable in Tor, but it's good tprevent future errors too. Found by doorss.
Correctly detect failures tcreate DNS requests when using Libevent versions before v2. (Before Libevent 2, we used our own evdns implementation. Its return values for Libevent's evdns_resolve_*() functions are not consistent with those from Libevent.) Fixes bug 2363; bugfix on 0.2.2.6-alpha. Found by "lodger".
Documentation, new in 0.2.2.21-alpha:
Document the default socks host and port (127.0.0.1:9050) for tor-resolve.

New in Tor 0.2.1.29 (Jan 18, 2011)

Major bugfixes (security):
Fix a heap overflow bug where an adversary could cause heap corruption. This bug probably allows remote code execution attacks. Reported by "debuger". Fixes CVE-2011-0427. Bugfix on 0.1.2.10-rc.
Prevent a denial-of-service attack by disallowing any zlib-compressed data whose compression factor is implausibly high. Fixes part of bug 2324; reported by "doorss".
Zerout a few more keys in memory before freeing them. Fixes bug 2384 and part of bug 2385. These key instances found by "cypherpunks", based on Andrew Case's report about being able tfind sensitive data in Tor's memory space if you have enough permissions. Bugfix on 0.0.2pre9.
Major bugfixes (crashes):
Prevent calls tLibevent from inside Libevent log handlers. This had potential tcause a nasty set of crashes, especially if running Libevent with debug logging enabled, and running Tor with a controller watching for low-severity log messages. Bugfix on 0.1.0.2-rc. Fixes bug 2190.
Add a check for SIZE_T_MAX ttor_realloc() ttry tavoid underflow errors there too. Fixes the other part of bug 2324.
Fix a bug where we would assert if we ever had a cached-descriptors.new file (or another file read directly intmemory) of exactly SIZE_T_CEILING bytes. Fixes bug 2326; bugfix on 0.2.1.25. Found by doorss.
Fix some potential asserts and parsing issues with grossly malformed router caches. Fixes bug 2352; bugfix on Tor 0.2.1.27. Found by doorss.
Minor bugfixes (other):
Fix a bug with handling misformed replies treverse DNS lookup requests in DNSPort. Bugfix on Tor 0.2.0.1-alpha. Related ta bug reported by doorss.
Fix compilation on mingw when a pthreads compatibility library has been installed. (We don't want tuse it, swe shouldn't be including pthread.h.) Fixes bug 2313; bugfix on 0.1.0.1-rc.
Fix a bug where we would declare that we had run out of virtual addresses when the address space was only half-exhausted. Bugfix on 0.1.2.1-alpha.
Correctly handle the case where AutomapHostsOnResolve is set but nvirtual addresses are available. Fixes bug 2328; bugfix on 0.1.2.1-alpha. Bug found by doorss.
Correctly handle wrapping around twhen we run out of virtual address space. Found by cypherpunks, bugfix on 0.2.0.5-alpha.
The 0.2.1.28 tarball was missing src/common/OpenBSD_malloc_Linux.c because we built it with a too-old version of automake. Thus that release broke ./configure --enable-openbsd-malloc, which is popular among really fast exit relays on Linux.
Minor features:
Update tthe January 1 2011 Maxmind GeoLite Country database.
Introduce output size checks on all of our decryption functions.
Build changes:
Tor does not build packages correctly with Automake 1.6 and earlier; added a check tMakefile.am tmake sure that we're building with Automake 1.7 or later.

New in Tor 0.2.1.28 (Dec 21, 2010)

New in Tor 0.2.1.27 (Nov 27, 2010)

Major bugfixes:
Resolve an incompatibility with OpenSSL 0.9.8p and OpenSSL 1.0.0b: Nlonger set the tlsext_host_name extension on server SSL objects; but continue tset it on client SSL objects. Our goal in setting it was timitate a browser, not a vhosting server. Fixes bug 2204; bugfix on 0.2.1.1-alpha.
Dnot log messages tthe controller while shrinking buffer freelists. Doing swould sometimes make the controller connection try tallocate a buffer chunk, which would mess up the internals of the freelist and cause an assertion failure. Fixes bug 1125; fixed by Robert Ransom. Bugfix on 0.2.0.16-alpha.
Learn our external IP address when we're a relay or bridge, even if we set PublishServerDescriptor t0. Bugfix on 0.2.0.3-alpha, where we introduced bridge relays that don't need tpublish tbe useful. Fixes bug 2050.
Deven more treject (and not just ignore) annotations on router descriptors received anywhere but from the cache. Previously we would ignore such annotations at first, but cache them tdisk anyway. Bugfix on 0.2.0.8-alpha. Found by piebeer.
When you're using bridges and your network goes away and your bridges get marked as down, recover when you attempt a new socks connection (if the network is back), rather than waiting up tan hour ttry fetching new descriptors for your bridges. Bugfix on 0.2.0.3-alpha; fixes bug 1981.
Major features:
Move tthe November 2010 Maxmind GeoLite country db (rather than the June 2009 ip-to-country GeoIP db) for our statistics that count how many users relays are seeing from each country. Now we'll have more accurate data, especially for many African countries.
New directory authorities:
Set up maatuska (run by Linus Nordberg) as the eighth v3 directory authority.
Minor bugfixes:
Fix an assertion failure that could occur in directory caches or bridge users when using a very short voting interval on a testing network. Diagnosed by Robert Hogan. Fixes bug 1141; bugfix on 0.2.0.8-alpha.
Enforce multiplicity rules when parsing annotations. Bugfix on 0.2.0.8-alpha. Found by piebeer.
Allow handshaking OR connections ttake a full KeepalivePeriod seconds thandshake. Previously, we would close them after IDLE_OR_CONN_TIMEOUT (180) seconds, the same timeout as if they were open. Bugfix on 0.2.1.26; fixes bug 1840. Thanks tmingw-san for analysis help.
When building with --enable-gcc-warnings on OpenBSD, disable warnings in system headers. This makes --enable-gcc-warnings pass on OpenBSD 4.8.
Minor features:
Exit nodes didn't recognize EHOSTUNREACH as a plausible error code, and ssent back END_STREAM_REASON_MISC. Clients now recognize a new stream ending reason for this case: END_STREAM_REASON_NOROUTE. Servers can start sending this code when enough clients recognize it. Bugfix on 0.1.0.1-rc; fixes part of bug 1793.
Build correctly on mingw with more recent versions of OpenSSL 0.9.8. Patch from mingw-san.
Removed files:
Remove the old debian/ directory from the main Tor distribution. The official Tor-for-debian git repository lives at the URL https://git.torproject.org/debian/tor.git
Stop shipping the old doc/website/ directory in the tarball. We changed the website format in late 2010, and what we shipped in 0.2.1.26 really wasn't that useful anyway.

New in Tor 0.2.2.18 Alpha (Nov 19, 2010)

Major bugfixes:
Do even more to reject (and not just ignore) annotations on router descriptors received anywhere but from the cache. Previously we would ignore such annotations at first, but cache them to disk anyway. Bugfix on 0.2.0.8-alpha. Found by piebeer.
Do not log messages to the controller while shrinking buffer freelists. Doing so would sometimes make the controller connection try to allocate a buffer chunk, which would mess up the internals of the freelist and cause an assertion failure. Fixes bug 1125; fixed by Robert Ransom. Bugfix on 0.2.0.16-alpha.
Learn our external IP address when we're a relay or bridge, even if we set PublishServerDescriptor to 0. Bugfix on 0.2.0.3-alpha, where we introduced bridge relays that don't need to publish to be useful. Fixes bug 2050.
Maintain separate TLS contexts and certificates for incoming and outgoing connections in bridge relays. Previously we would use the same TLS contexts and certs for incoming and outgoing connections. Bugfix on 0.2.0.3-alpha; addresses bug 988.
Maintain separate identity keys for incoming and outgoing TLS contexts in bridge relays. Previously we would use the same identity keys for incoming and outgoing TLS contexts. Bugfix on 0.2.0.3-alpha; addresses the other half of bug 988.
Avoid an assertion failure when we as an authority receive a duplicate upload of a router descriptor that we already have, but which we previously considered an obsolete descriptor. Fixes another case of bug 1776. Bugfix on 0.2.2.16-alpha.
Avoid a crash bug triggered by looking at a dangling pointer while setting the network status consensus. Found by Robert Ransom. Bugfix on 0.2.2.17-alpha. Fixes bug 2097.
Fix a logic error where servers that _didn't_ act as exits would try to keep their server lists more aggressively up to date than exits, when it was supposed to be the other way around. Bugfix on 0.2.2.17-alpha.
Minor bugfixes (on Tor 0.2.1.x and earlier):
When we're trying to guess whether we know our IP address as a relay, we would log various ways that we failed to guess our address, but never log that we ended up guessing it successfully. Now add a log line to help confused and anxious relay operators. Bugfix on 0.1.2.1-alpha; fixes bug 1534.
Bring the logic that gathers routerinfos and assesses the acceptability of circuits into line. This prevents a Tor OP from getting locked in a cycle of choosing its local OR as an exit for a path (due to a .exit request) and then rejecting the circuit because its OR is not listed yet. It also prevents Tor clients from using an OR running in the same instance as an exit (due to a .exit request) if the OR does not meet the same requirements expected of an OR running elsewhere. Fixes bug 1859; bugfix on 0.1.0.1-rc.
Correctly describe errors that occur when generating a TLS object. Previously we would attribute them to a failure while generating a TLS context. Patch by Robert Ransom. Bugfix on 0.1.0.4-rc; fixes bug 1994.
Enforce multiplicity rules when parsing annotations. Bugfix on 0.2.0.8-alpha. Found by piebeer.
Fix warnings that newer versions of autoconf produced during ./autogen.sh. These warnings appear to be harmless in our case, but they were extremely verbose. Fixes bug 2020.
Minor bugfixes (on Tor 0.2.2.x):
Enable protection of small arrays whenever we build with gcc hardening features, not only when also building with warnings enabled. Fixes bug 2031; bugfix on 0.2.2.14-alpha. Reported by keb.
Minor features:
Make hidden services work better in private Tor networks by not requiring any uptime to join the hidden service descriptor DHT. Implements ticket 2088.
Rate-limit the "your application is giving Tor only an IP address" warning. Addresses bug 2000; bugfix on 0.0.8pre2.
When AllowSingleHopExits is set, print a warning to explain to the relay operator why most clients are avoiding her relay.
Update to the November 1 2010 Maxmind GeoLite Country database.
Code simplifications and refactoring:
When we fixed bug 1038 we had to put in a restriction not to send RELAY_EARLY cells on rend circuits. This was necessary as long as relays using Tor 0.2.1.3-alpha through 0.2.1.18-alpha were active. Now remove this obsolete check. Resolves bug 2081.
Some options used different conventions for uppercasing of acronyms when comparing manpage and source. Fix those in favor of the manpage, as it makes sense to capitalize acronyms.
Remove the torrc.complete file. It hasn't been kept up to date and users will have better luck checking out the manpage.
Remove the obsolete "NoPublish" option; it has been flagged as obsolete and has produced a warning since 0.1.1.18-rc.
Remove everything related to building the expert bundle for OS X. It has confused many users, doesn't work right on OS X 10.6, and is hard to get rid of once installed. Resolves bug 1274.

New in Tor 0.2.1.25 (Apr 1, 2010)

New in Tor 0.2.1.22 (Jan 22, 2010)

New in Tor 0.2.1.21 (Jan 7, 2010)

New in Tor 0.2.2.6 Alpha (Nov 23, 2009)

Major features:
Directory authorities can now create, vote, and serve on multiple parallel formats of directory data as part of their voting process. This is a partial implementation of Proposal 162: "Publish the consensus in multiple flavors."
Directory authorities can now agree on and publish small summaries of router information that clients can use in place of regular server descriptors. This will eventually allow clients to use far less bandwidth for downloading information about the network. This begins the implementation of of Proposal 158: "Clients download a consensus + Microdescriptors".
The directory voting system is now extensible to use multiple hash algorithms for signatures and resource selection. Newer formats are signed with SHA256, with a possibility for moving to a better hash algorithm in the future.
New DisableAllSwap option. If set to 1, Tor will attempt to lock all current and future memory pages. On supported platforms, this should effectively disable any and all attempts to page out memory. Under the hood, DisableAllSwap uses mlockall() on unix-like platforms. Windows is currently unsupported. We believe that this feature works on modern Gnu/Linux distributions. Mac OS X appears to be broken by design. On reasonable *BSD systems it should also be supported but this is untested. This option requires that you start your Tor as root. If you use DisableAllSwap, please consider using the User option to properly reduce the privileges of your Tor.
Major bugfixes:
Work around a security feature in OpenSSL 0.9.8l that prevents our handshake from working unless we explicitly tell OpenSSL that we are using SSL renegotiation safely. We are, of course, but OpenSSL 0.9.8l won't work unless we say we are.
Code simplifications and refactorings:
Numerous changes, bugfixes, and workarounds from Nathan Freitas to help Tor build correctly for Android phones.
Begun converting Tor's signature and message digest logic to handle multiple hash algorithms.
Minor bugfixes:
Fix a crash bug when trying to initialize the evdns module in Libevent 2.
Stop logging at severity 'warn' when some other Tor client tries to establish a circuit with us using weak DH keys. It's a protocol violation, but that doesn't mean ordinary users need to hear about it. Fixes the bug part of bug 1114. Bugfix on 0.1.0.13.
Do not refuse to learn about authority certs and v2 networkstatus documents that are older than the latest consensus. This bug might have degraded client bootstrapping. Bugfix on 0.2.0.10-alpha. Spotted and fixed by xmux.
Fix numerous small code-flaws found by Coverity Scan Rung 3.
If all authorities restart at once right before a consensus vote, nobody will vote about "Running", and clients will get a consensus with no usable relays. Instead, authorities refuse to build a consensus if this happens. Bugfix on 0.2.0.10-alpha; fixes bug 1066.
If your relay can't keep up with the number of incoming create cells, it would log one warning per failure into your logs. Limit warnings to 1 per minute. Bugfix on 0.0.2pre10; fixes bug 1042.
Bridges do not use the default exit policy, but reject *:* by default. Fixes bug 1113.

New in Tor 0.2.2.5 Alpha (Oct 26, 2009)

New in Tor 0.2.1.20 (Oct 26, 2009)

New in Tor 0.2.1.17 RC (Jul 10, 2009)

Major features:
Clients now use the bandwidth values in the consensus, rather than the bandwidth values in each relay descriptor. This approach opens the door to more accurate bandwidth estimates once the directory authorities start doing active measurements. Implements more of proposal 141.
Major bugfixes:
When Tor clients restart after 1-5 days, they discard all their cached descriptors as too old, but they still use the cached consensus document. This approach is good for robustness, but bad for performance: since they don't know any bandwidths, they end up choosing at random rather than weighting their choice by speed. Fixed by the above feature of putting bandwidths in the consensus. Bugfix on 0.2.0.x.
Directory authorities were neglecting to mark relays down in their internal histories if the relays fall off the routerlist without ever being found unreachable. So there were relays in the histories that haven't been seen for eight months, and are listed as being up for eight months. This wreaked havoc on the "median wfu" and "median mtbf" calculations, in turn making Guard and Stable flags very wrong, hurting network performance. Fixes bugs 696 and 969. Bugfix on 0.2.0.6-alpha.
Minor bug fixes:
Serve the DirPortFrontPage page even when we have been approaching our quotas recently. Fixes bug 1013; bugfix on 0.2.1.8-alpha.
The control port would close the connection before flushing long replies, such as the network consensus, if a QUIT command was issued before the reply had completed. Now, the control port flushes all pending replies before closing the connection. Also fixed a spurious warning when a QUIT command is issued after a malformed or rejected AUTHENTICATE command, but before the connection was closed. Patch by Marcus Griep. Bugfix on 0.2.0.x; fixes bugs 1015 and 1016.
When we can't find an intro key for a v2 hidden service descriptor, fall back to the v0 hidden service descriptor and log a bug message. Workaround for bug 1024.
Fix a log message that did not respect the SafeLogging option. Resolves bug 1027.
Minor features:
If we're a relay and we change our IP address, be more verbose about the reason that made us change. Should help track down further bugs for relays on dynamic IP addresses.

New in Tor 0.2.1.16 RC (Jul 10, 2009)

New in Tor 0.2.0.35 (Jul 1, 2009)

New in Tor 0.2.1.15 RC (May 26, 2009)

New in Tor 0.2.1.14 RC (Apr 14, 2009)

Major features:
Clients replace entry guards that were chosen more than a few months ago. This change should significantly improve client performance, especially once more people upgrade, since relays that have been a guard for a long time are currently overloaded.
Major bugfixes (on 0.2.0):
Finally fix the bug where dynamic-IP relays disappear when their IP address changes: directory mirrors were mistakenly telling them their old address if they asked via begin_dir, so they never got an accurate answer about their new address, so they just vanished after a day. For belt-and-suspenders, relays that don't set Address in their config now avoid using begin_dir for all direct connections. Should fix bugs 827, 883, and 900.
Relays were falling out of the networkstatus consensus for part of a day if they changed their local config but the authorities discarded their new descriptor as "not sufficiently different". Now directory authorities accept a descriptor as changed if bandwidthrate or bandwidthburst changed. Partial fix for bug 962; patch by Sebastian.
Avoid crashing in the presence of certain malformed descriptors. Found by lark, and by automated fuzzing.
Minor features:
When generating circuit events with verbose nicknames for controllers, try harder to look up nicknames for routers on a circuit. (Previously, we would look in the router descriptors we had for nicknames, but not in the consensus.) Partial fix for bug 941.
If the bridge config line doesn't specify a port, assume 443. This makes bridge lines a bit smaller and easier for users to understand.
Raise the minimum bandwidth to be a relay from 20000 bytes to 20480 bytes (aka 20KB/s), to match our documentation. Also update directory authorities so they always assign the Fast flag to relays with 20KB/s of capacity. Now people running relays won't suddenly find themselves not seeing any use, if the network gets faster on average.
Update to the "April 3 2009" ip-to-country file.
Minor bugfixes:
Avoid trying to print raw memory to the logs when we decide to give up on downloading a given relay descriptor. Bugfix on 0.2.1.9-alpha.
In tor-resolve, when the Tor client to use is specified by :, actually use the specified port rather than defaulting to 9050. Bugfix on 0.2.1.6-alpha.
Make directory usage recording work again. Bugfix on 0.2.1.6-alpha.
When starting with a cache over a few days old, do not leak memory for the obsolete router descriptors in it. Bugfix on 0.2.0.33.
Avoid double-free on list of successfully uploaded hidden service discriptors. Fix for bug 948. Bugfix on 0.2.1.6-alpha.
Change memarea_strndup() implementation to work even when duplicating a string at the end of a page. This bug was harmless for now, but could have meant crashes later. Fix by lark. Bugfix on 0.2.1.1-alpha.
Limit uploaded directory documents to be 16M rather than 500K. The directory authorities were refusing v3 consensus votes from other authorities, since the votes are now 504K. Fixes bug 959; bugfix on 0.0.2pre17 (where we raised it from 50K to 500K ;).
Directory authorities should never send a 503 "busy" response to requests for votes or keys. Bugfix on 0.2.0.8-alpha; exposed by bug 959.

New in Tor 0.2.1.9 Alpha (Jan 5, 2009)

New directory authorities:
gabelmoo (the authority run by Karsten Loesing) now has a newIP address.
Security fixes:
Never use a connection with a mismatched address to extend acircuit, unless that connection is canonical. A canonicalconnection is one whose address is authenticated by the router'sidentity key, either in a NETINFO cell or in a router descriptor.
Avoid a possible memory corruption bug when receiving hidden servicedescriptors. Bugfix on 0.2.1.6-alpha.
Major bugfixes:
Fix a logic error that would automatically reject all but the firstconfigured DNS server. Bugfix on 0.2.1.5-alpha. Possible fix forpart of bug 813/868. Bug spotted by coderman.
When a stream at an exit relay is in state "resolving" or"connecting" and it receives an "end" relay cell, the exit relaywould silently ignore the end cell and not close the stream. Ifthe client never closes the circuit, then the exit relay nevercloses the TCP connection. Bug introduced in 0.1.2.1-alpha;reported by "wood".
When we can't initialize DNS because the network is down, do notautomatically stop Tor from starting. Instead, retry faileddns_inits() every 10 minutes, and change the exit policy to reject*:* until one succeeds. Fixes bug 691.
Minor features:
Give a better error message when an overzealous init script says"sudo -u username tor --user username". Makes Bug 882 easier forusers to diagnose.
When a directory authority gives us a new guess for our IP address,log which authority we used. Hopefully this will help us debugthe recent complaints about bad IP address guesses.
Detect svn revision properly when we're using git-svn.
Try not to open more than one descriptor-downloading connectionto an authority at once. This should reduce load on directoryauthorities. Fixes bug 366.
Add cross-certification to newly generated certificates, so thata signing key is enough information to look up a certificate.Partial implementation of proposal 157.
Start serving certificates by pairs. Partial implementation of proposal 157.
Clients now never report any stream end reason except 'MISC'.Implements proposal 148.
On platforms with a maximum syslog string length, truncate syslogmessages to that length ourselves, rather than relying on thesystem to do it for us.
Optimize out calls to time(NULL) that occur for every IO operation,or for every cell. On systems where time() is a slow syscall,this fix will be slightly helpful.
Exit servers can now answer resolve requests for ip6.arpa addresses.
When we download a descriptor that we then immediately (asa directory authority) reject, do not retry downloading it rightaway. Should save some bandwidth on authorities. Fix for bug888. Patch by Sebastian Hahn.
When a download gets us zero good descriptors, do not notifyTor that new directory information has arrived.
Avoid some nasty corner cases in the logic for marking connectionsas too old or obsolete or noncanonical for circuits.
Minor features (controller):
New CONSENSUS_ARRIVED event to note when a new consensus hasbeen fetched and validated.
When we realize that another process has modified our cacheddescriptors file, print out a more useful error message ratherthan triggering an assertion. Fixes bug 885. Patch from Karsten.
Add an internal-use-only __ReloadTorrcOnSIGHUP option forcontrollers to prevent SIGHUP from reloading theconfiguration. Fixes bug 856.
Minor bugfixes:
Resume using the correct "REASON=" stream when telling thecontroller why we closed a stream. Bugfix in 0.2.1.1-alpha.
When a canonical connection appears later in our internal listthan a noncanonical one for a given OR ID, always use thecanonical one. Bugfix on 0.2.0.12-alpha. Fixes bug 805.Spotted by rovv.
Clip the MaxCircuitDirtiness config option to a minimum of 10seconds. Warn the user if lower values are given in theconfiguration. Bugfix on 0.1.0.1-rc. Patch by Sebastian.
Clip the CircuitBuildTimeout to a minimum of 30 seconds. Warn theuser if lower values are given in the configuration. Bugfix on0.1.1.17-rc. Patch by Sebastian.
Fix a race condition when freeing keys shared between main threadand CPU workers that could result in a memory leak. Bugfix on0.1.0.1-rc. Fixes bug 889.
Minor bugfixes (hidden services):
Do not throw away existing introduction points on SIGHUP (bugfix on0.0.6pre1); also, do not stall hidden services because we'rethrowing away introduction points; bugfix on 0.2.1.7-alpha. Spottedby John Brooks. Patch by Karsten. Fixes bug 874.
Fix a memory leak when we decline to add a v2 rendezvousdescriptor to the cache because we already had a v0 descriptorwith the same ID. Bugfix on 0.2.0.18-alpha.
Deprecated and removed features:
RedirectExits has been removed. It was deprecated since0.2.0.3-alpha.
Finally remove deprecated "EXTENDED_FORMAT" controller feature. Ithas been called EXTENDED_EVENTS since 0.1.2.4-alpha.
Cell pools are now always enabled; --disable-cell-pools is ignored.
Code simplifications and refactoring:
Rename the confusing or_is_obsolete field to the more appropriateis_bad_for_new_circs, and move it to or_connection_t where itbelongs.
Move edge-only flags from connection_t to edge_connection_t: notonly is this better coding, but on machines of plausible alignment,it should save 4-8 bytes per connection_t. "Every little bit helps."
Rename ServerDNSAllowBrokenResolvConf to ServerDNSAllowBrokenConfigfor consistency; keep old option working for backward compatibility.
Simplify the code for finding connections to use for a circuit.

New in Tor 0.2.1.8 Alpha (Dec 10, 2008)

Major features:
New DirPortFrontPage option that takes an html file and publishes it as "/" on the DirPort. Now relay operators can provide a disclaimer without needing to set up a separate webserver. There's a sample disclaimer in contrib/tor-exit-notice.html.
Security fixes:
When the client is choosing entry guards, now it selects at most one guard from a given relay family. Otherwise we could end up with all of our entry points into the network run by the same operator. Suggested by Camilo Viecco. Fix on 0.1.1.11-alpha.
Major bugfixes:
Fix a DOS opportunity during the voting signature collection process at directory authorities. Spotted by rovv. Bugfix on 0.2.0.x.
Fix a possible segfault when establishing an exit connection. Bugfix on 0.2.1.5-alpha.
Minor bugfixes:
Get file locking working on win32. Bugfix on 0.2.1.6-alpha. Fixes bug 859.
Made Tor a little less aggressive about deleting expired certificates. Partial fix for bug 854.
Stop doing unaligned memory access that generated bus errors on sparc64. Bugfix on 0.2.0.10-alpha. Fix for bug 862.
Fix a crash bug when changing EntryNodes from the controller. Bugfix on 0.2.1.6-alpha. Fix for bug 867. Patched by Sebastian.
Make USR2 log-level switch take effect immediately. Bugfix on 0.1.2.8-beta.
If one win32 nameserver fails to get added, continue adding the rest, and don't automatically fail.
Use fcntl() for locking when flock() is not available. Should fix compilation on Solaris. Should fix Bug 873. Bugfix on 0.2.1.6-alpha.
Do not mark smartlist_bsearch_idx() function as ATTR_PURE. This bug could make gcc generate non-functional binary search code. Bugfix on 0.2.0.10-alpha.
Build correctly on platforms without socklen_t.
Avoid potential crash on internal error during signature collection. Fixes bug 864. Patch from rovv.
Do not use C's stdio library for writing to log files. This will improve logging performance by a minute amount, and will stop leaking fds when our disk is full. Fixes bug 861.
Stop erroneous use of O_APPEND in cases where we did not in fact want to re-seek to the end of a file before every last write().
Correct handling of possible malformed authority signing key certificates with internal signature types. Fixes bug 880. Bugfix on 0.2.0.3-alpha.
Fix a hard-to-trigger resource leak when logging credential status. CID 349.
Minor features:
Directory mirrors no longer fetch the v1 directory or running-routers files. They are obsolete, and nobody asks for them anymore. This is the first step to making v1 authorities obsolete.
Minor features (controller):
Return circuit purposes in response to GETINFO circuit-status. Fixes bug 858.

New in Tor 0.2.0.32 (Nov 24, 2008)

Security fixes:
The "User" and "Group" config options did not clear the supplementary group entries for the Tor process. The "User" option is now more robust, and we now set the groups to the specified user's primary group. The "Group" option is now ignored. For more detailed logging on credential switching, set CREDENTIAL_LOG_LEVEL in common/compat.c to LOG_NOTICE or higher. Patch by Jacob Appelbaum and Steven Murdoch. Bugfix on 0.0.2pre14. Fixes bug 848 and 857.
The "ClientDNSRejectInternalAddresses" config option wasn't being consistently obeyed: if an exit relay refuses a stream because its exit policy doesn't allow it, we would remember what IP address the relay said the destination address resolves to, even if it's an internal IP address. Bugfix on 0.2.0.7-alpha; patch by rovv.
Major bugfixes:
Fix a DOS opportunity during the voting signature collection process at directory authorities. Spotted by rovv. Bugfix on 0.2.0.x.
Major bugfixes (hidden services):
When fetching v0 and v2 rendezvous service descriptors in parallel, we were failing the whole hidden service request when the v0 descriptor fetch fails, even if the v2 fetch is still pending and might succeed. Similarly, if the last v2 fetch fails, we were failing the whole hidden service request even if a v0 fetch is still pending. Fixes bug 814. Bugfix on 0.2.0.10-alpha.
When extending a circuit to a hidden service directory to upload a rendezvous descriptor using a BEGIN_DIR cell, almost 1/6 of all requests failed, because the router descriptor has not been downloaded yet. In these cases, do not attempt to upload the rendezvous descriptor, but wait until the router descriptor is downloaded and retry. Likewise, do not attempt to fetch a rendezvous descriptor from a hidden service directory for which the router descriptor has not yet been downloaded. Fixes bug 767. Bugfix on 0.2.0.10-alpha.
Minor bugfixes:
Fix several infrequent memory leaks spotted by Coverity.
When testing for libevent functions, set the LDFLAGS variable correctly. Found by Riastradh.
Avoid a bug where the FastFirstHopPK 0 option would keep Tor from bootstrapping with tunneled directory connections. Bugfix on 0.1.2.5-alpha. Fixes bug 797. Found by Erwin Lam.
When asked to connect to A.B.exit:80, if we don't know the IP for A and we know that server B rejects most-but-not all connections to port 80, we would previously reject the connection. Now, we assume the user knows what they were asking for. Fixes bug 752. Bugfix on 0.0.9rc5. Diagnosed by BarkerJr.
If we overrun our per-second write limits a little, count this as having used up our write allocation for the second, and choke outgoing directory writes. Previously, we had only counted this when we had met our limits precisely. Fixes bug 824. Patch from by rovv. Bugfix on 0.2.0.x (??).
Remove the old v2 directory authority 'lefkada' from the default list. It has been gone for many months.
Stop doing unaligned memory access that generated bus errors on sparc64. Bugfix on 0.2.0.10-alpha. Fixes bug 862.
Make USR2 log-level switch take effect immediately. Bugfix on 0.1.2.8-beta.
Minor bugfixes (controller):
Make DNS resolved events into "CLOSED", not "FAILED". Bugfix on 0.1.2.5-alpha. Fix by Robert Hogan. Resolves bug 807.

New in Tor 0.2.1.7 Alpha (Nov 21, 2008)

Security fixes:
The "ClientDNSRejectInternalAddresses" config option wasn't being consistently obeyed: if an exit relay refuses a stream because its exit policy doesn't allow it, we would remember what IP address the relay said the destination address resolves to, even if it's an internal IP address. Bugfix on 0.2.0.7-alpha; patch by rovv.
The "User" and "Group" config options did not clear the supplementary group entries for the Tor process. The "User" option is now more robust, and we now set the groups to the specified user's primary group. The "Group" option is now ignored. For more detailed logging on credential switching, set CREDENTIAL_LOG_LEVEL in common/compat.c to LOG_NOTICE or higher. Patch by Jacob Appelbaum and Steven Murdoch. Bugfix on 0.0.2pre14. Fixes bug 848.
Do not use or believe expired v3 authority certificates. Patch from Karsten. Bugfix in 0.2.0.x. Fixes bug 851.
Minor features:
Now NodeFamily and MyFamily config options allow spaces in identity fingerprints, so it's easier to paste them in. Suggested by Lucky Green.
Implement the 0x20 hack to better resist DNS poisoning: set the case on outgoing DNS requests randomly, and reject responses that do not match the case correctly. This logic can be disabled with the ServerDNSRamdomizeCase setting, if you are using one of the 0.3% of servers that do not reliably preserve case in replies. See "Increased DNS Forgery Resistance through 0x20-Bit Encoding" for more info.
Preserve case in replies to DNSPort requests in order to support the 0x20 hack for resisting DNS poisoning attacks.
Hidden service performance improvements:
When the client launches an introduction circuit, retry with a new circuit after 30 seconds rather than 60 seconds.
Launch a second client-side introduction circuit in parallel after a delay of 15 seconds (based on work by Christian Wilms).
Hidden services start out building five intro circuits rather than three, and when the first three finish they publish a service descriptor using those. Now we publish our service descriptor much faster after restart.
Minor bugfixes:
Minor fix in the warning messages when you're having problems bootstrapping; also, be more forgiving of bootstrap problems when we're still making incremental progress on a given bootstrap phase.
When we're choosing an exit node for a circuit, and we have no pending streams, choose a good general exit rather than one that supports "all the pending streams". Bugfix on 0.1.1.x. Fix by rovv.
Send a valid END cell back when a client tries to connect to a nonexistent hidden service port. Bugfix on 0.1.2.15. Fixes bug 840. Patch from rovv.
If a broken client asks a non-exit router to connect somewhere, do not even do the DNS lookup before rejecting the connection. Fixes another case of bug 619. Patch from rovv.
Fix another case of assuming, when a specific exit is requested, that we know more than the user about what hosts it allows. Fixes another case of bug 752. Patch from rovv.
Check which hops rendezvous stream cells are associated with to prevent possible guess-the-streamid injection attacks from intermediate hops. Fixes another case of bug 446. Based on patch from rovv.
Avoid using a negative right-shift when comparing 32-bit addresses. Possible fix for bug 845 and bug 811.
Make the assert_circuit_ok() function work correctly on circuits that have already been marked for close.
Fix read-off-the-end-of-string error in unit tests when decoding introduction points.
Fix uninitialized size field for memory area allocation: may improve memory performance during directory parsing.
Treat duplicate certificate fetches as failures, so that we do not try to re-fetch an expired certificate over and over and over.
Do not say we're fetching a certificate when we'll in fact skip it because of a pending download.

New in Tor 0.2.1.6 Alpha (Oct 13, 2008)

Implement proposal 121: make it possible to build hidden services that only certain clients are allowed to connect to. This is enforced at several points, so that unauthorized clients are unable to send INTRODUCE cells to the service, or even (depending on the type of authentication) to learn introduction points. This feature raises the bar for certain kinds of active attacks against hidden services. Code by Karsten Loesing.
Relays now store and serve v2 hidden service descriptors by default, i.e., the new default value for HidServDirectoryV2 is 1. This is the last step in proposal 114, which aims to make hidden service lookups more reliable.
Start work to allow node restrictions to include country codes. The syntax to exclude nodes in a country with country code XX is "ExcludeNodes {XX}". Patch from Robert Hogan. It still needs some refinement to decide what config options should take priority if you ask to both use a particular node and exclude it.
Allow ExitNodes list to include IP ranges and country codes, just like the Exclude*Nodes lists. Patch from Robert Hogan.
Fix a bug when parsing ports in tor_addr_port_parse() that caused Tor to fail to start if you had it configured to use a bridge relay. Fixes bug 809. Bugfix on 0.2.1.5-alpha.
When extending a circuit to a hidden service directory to upload a rendezvous descriptor using a BEGIN_DIR cell, almost 1/6 of all requests failed, because the router descriptor had not been downloaded yet. In these cases, we now wait until the router descriptor is downloaded, and then retry. Likewise, clients now skip over a hidden service directory if they don't yet have its router descriptor, rather than futilely requesting it and putting mysterious complaints in the logs. Fixes bug 767. Bugfix on 0.2.0.10-alpha.
When fetching v0 and v2 rendezvous service descriptors in parallel, we were failing the whole hidden service request when the v0 descriptor fetch fails, even if the v2 fetch is still pending and might succeed. Similarly, if the last v2 fetch fails, we were failing the whole hidden service request even if a v0 fetch is still pending. Fixes bug 814. Bugfix on 0.2.0.10-alpha.
DNS replies need to have names matching their requests, but these names should be in the questions section, not necessarily in the answers section. Fixes bug 823. Bugfix on 0.2.1.5-alpha.
Update to the "September 1 2008" ip-to-country file.
Allow ports 465 and 587 in the default exit policy again. We had rejected them in 0.1.0.15, because back in 2005 they were commonly misconfigured and ended up as spam targets. We hear they are better locked down these days.
Use a lockfile to make sure that two Tor processes are not simultaneously running with the same datadir.
Serve the latest v3 networkstatus consensus via the control port. Use "getinfo dir/status-vote/current/consensus" to fetch it.
Better logging about stability/reliability calculations on directory servers.
Drop the requirement to have an open dir port for storing and serving v2 hidden service descriptors.
Directory authorities now serve a /tor/dbg-stability.txt URL to help debug WFU and MTBF calculations.
Implement most of Proposal 152: allow specialized servers to permit single-hop circuits, and clients to use those servers to build single-hop circuits when using a specialized controller. Patch from Josh Albrecht. Resolves feature request 768.
Add a -p option to tor-resolve for specifying the SOCKS port: some people find host:port too confusing.
Make TrackHostExit mappings expire a while after their last use, not after their creation. Patch from Robert Hogan.
Provide circuit purposes along with circuit events to the controller.
Fix compile on OpenBSD 4.4-current. Bugfix on 0.2.1.5-alpha. Reported by Tas.
Fixed some memory leaks -- some quite frequent, some almost impossible to trigger -- based on results from Coverity.
When testing for libevent functions, set the LDFLAGS variable correctly. Found by Riastradh.
Fix an assertion bug in parsing policy-related options; possible fix for bug 811.
Catch and report a few more bootstrapping failure cases when Tor fails to establish a TCP connection. Cleanup on 0.2.1.x.
Avoid a bug where the FastFirstHopPK 0 option would keep Tor from bootstrapping with tunneled directory connections. Bugfix on 0.1.2.5-alpha. Fixes bug 797. Found by Erwin Lam.
When asked to connect to A.B.exit:80, if we don't know the IP for A and we know that server B rejects most-but-not all connections to port 80, we would previously reject the connection. Now, we assume the user knows what they were asking for. Fixes bug 752. Bugfix on 0.0.9rc5. Diagnosed by BarkerJr.
If we are not using BEGIN_DIR cells, don't attempt to contact hidden service directories if they have no advertised dir port. Bugfix on 0.2.0.10-alpha.
If we overrun our per-second write limits a little, count this as having used up our write allocation for the second, and choke outgoing directory writes. Previously, we had only counted this when we had met our limits precisely. Fixes bug 824. Patch from by rovv. Bugfix on 0.2.0.x (??).
Avoid a "0 divided by 0" calculation when calculating router uptime at directory authorities. Bugfix on 0.2.0.8-alpha.
Make DNS resolved controller events into "CLOSED", not "FAILED". Bugfix on 0.1.2.5-alpha. Fix by Robert Hogan. Resolves bug 807.
Fix a bug where an unreachable relay would establish enough reachability testing circuits to do a bandwidth test -- if we already have a connection to the middle hop of the testing circuit, then it could establish the last hop by using the existing connection. Bugfix on 0.1.2.2-alpha, exposed when we made testing circuits no longer use entry guards in 0.2.1.3-alpha.
If we have correct permissions on $datadir, we complain to stdout and fail to start. But dangerous permissions on $datadir/cached-status/ would cause us to open a log and complain there. Now complain to stdout and fail to start in both cases. Fixes bug 820, reported by seeess.
Remove the old v2 directory authority 'lefkada' from the default list. It has been gone for many months.
Revise the connection_new functions so that a more typesafe variant exists. This will work better with Coverity, and let us find any actual mistakes we're making here.
Refactor unit testing logic so that dmalloc can be used sensibly with unit tests to check for memory leaks.
Move all hidden-service related fields from connection and circuit structure to substructures: this way they won't eat so much memory.

New in Tor 0.2.1.5 Alpha (Sep 10, 2008)

Convert many internal address representations to optionally hold IPv6 addresses.
Generate and accept IPv6 addresses in many protocol elements.
Make resolver code handle nameservers located at ipv6 addresses.
Begin implementation of proposal 121 ("Client authorization for hidden services"): configure hidden services with client authorization, publish descriptors for them, and configure authorization data for hidden services at clients. The next step is to actually access hidden services that perform client authorization.
More progress toward proposal 141: Network status consensus documents and votes now contain bandwidth information for each router and a summary of that router's exit policy. Eventually this will be used by clients so that they do not have to download every known descriptor before building circuits.
When sending CREATED cells back for a given circuit, use a 64-bit connection ID to find the right connection, rather than an addr:port combination. Now that we can have multiple OR connections between the same ORs, it is no longer possible to use addr:port to uniquely identify a connection.
Relays now reject risky extend cells: if the extend cell includes a digest of all zeroes, or asks to extend back to the relay that sent the extend cell, tear down the circuit. Ideas suggested by rovv.
If not enough of our entry guards are available so we add a new one, we might use the new one even if it overlapped with the current circuit's exit relay (or its family). Anonymity bugfix pointed out by rovv.
Recover 3-7 bytes that were wasted per memory chunk. Fixes bug 794; bug spotted by rovv. Bugfix on 0.2.0.1-alpha.
When using the TransPort option on OpenBSD, and using the User option to change UID and drop privileges, make sure to open /dev/pf before dropping privileges. Fixes bug 782. Patch from Christopher Davis. Bugfix on 0.1.2.1-alpha.
Correctly detect the presence of the linux/netfilter_ipv4.h header when building against recent kernels. Bugfix on 0.1.2.1-alpha.
Add a missing safe_str() call for a debug log message.
Use 64 bits instead of 32 bits for connection identifiers used with the controller protocol, to greatly reduce risk of identifier reuse.
Make the autoconf script accept the obsolete --with-ssl-dir option as an alias for the actually-working --with-openssl-dir option. Fix the help documentation to recommend --with-openssl-dir. Based on a patch by "Dave". Bugfix on 0.2.0.1-alpha.
Rate-limit too-many-sockets messages: when they happen, they happen a lot. Resolves bug 748.
Resist DNS poisoning a little better by making sure that names in answer sections match.
Print the SOCKS5 error message string as well as the error code when a tor-resolve request fails. Patch from Jacob.

New in Tor 0.2.0.31 (Sep 10, 2008)

Make sure that two circuits can never exist on the same connection with the same circuit ID, even if one is marked for close. This is conceivably a bugfix for bug 779. Bugfix on 0.1.0.4-rc.
Relays now reject risky extend cells: if the extend cell includes a digest of all zeroes, or asks to extend back to the relay that sent the extend cell, tear down the circuit. Ideas suggested by rovv.
If not enough of our entry guards are available so we add a new one, we might use the new one even if it overlapped with the current circuit's exit relay (or its family). Anonymity bugfix pointed out by rovv.
Recover 3-7 bytes that were wasted per memory chunk. Fixes bug 794; bug spotted by rovv. Bugfix on 0.2.0.1-alpha.
Correctly detect the presence of the linux/netfilter_ipv4.h header when building against recent kernels. Bugfix on 0.1.2.1-alpha.
Pick size of default geoip filename string correctly on windows. Fixes bug 806. Bugfix on 0.2.0.30.
Make the autoconf script accept the obsolete --with-ssl-dir option as an alias for the actually-working --with-openssl-dir option. Fix the help documentation to recommend --with-openssl-dir. Based on a patch by "Dave". Bugfix on 0.2.0.1-alpha.
Disallow session resumption attempts during the renegotiation stage of the v2 handshake protocol. Clients should never be trying session resumption at this point, but apparently some did, in ways that caused the handshake to fail. Bug found by Geoff Goodell. Bugfix on 0.2.0.20-rc.
When using the TransPort option on OpenBSD, and using the User option to change UID and drop privileges, make sure to open /dev/pf before dropping privileges. Fixes bug 782. Patch from Christopher Davis. Bugfix on 0.1.2.1-alpha.
Try to attach connections immediately upon receiving a RENDEZVOUS2 or RENDEZVOUS_ESTABLISHED cell. This can save a second or two on the client side when connecting to a hidden service. Bugfix on 0.0.6pre1. Found and fixed by Christian Wilms; resolves bug 743.
When closing an application-side connection because its circuit is getting torn down, generate the stream event correctly. Bugfix on 0.1.2.x. Anonymous patch.

New in Tor 0.2.1.4 Alpha (Aug 12, 2008)

New in Tor 0.2.1.2 Alpha / 0.2.0.29 RC (Jul 10, 2008)

If you have more than one bridge but don't know their keys, you would only launch a request for the descriptor of the first one on your list. (Tor considered launching requests for the others, but found that it already had a connection on the way for $0000...0000 so it didn't open another.) Bugfix on 0.2.0.x.
If you have more than one bridge but don't know their keys, and the connection to one of the bridges failed, you would cancel all pending bridge connections. (After all, they all have the same digest.) Bugfix on 0.2.0.x.
When a hidden service was trying to establish an introduction point, and Tor had built circuits preemptively for such purposes, we were ignoring all the preemptive circuits and launching a new one instead. Bugfix on 0.2.0.14-alpha.
When a hidden service was trying to establish an introduction point, and Tor *did* manage to reuse one of the preemptively built circuits, it didn't correctly remember which one it used, so it asked for another one soon after, until there were no more preemptive circuits, at which point it launched one from scratch. Bugfix on 0.0.9.x.
Make directory servers include the X-Your-Address-Is: http header in their responses even for begin_dir conns. Now clients who only ever use begin_dir connections still have a way to learn their IP address. Fixes bug 737; bugfix on 0.2.0.22-rc. Reported by goldy.
Fix a macro/CPP interactions that was confusing some compilers: some GCCs don't like #if/#endif pairs inside macro arguments. Fix for bug 707.
Fix macro collision between OpenSSL 0.9.8h and Windows headers. Fixes bug 704; fix from Steven Murdoch.
When opening /dev/null in finish_daemonize(), do not pass the O_CREAT flag. Fortify was complaining, and correctly so. Fixes bug 742; fix from Michael Scherer. Bugfix on 0.0.2pre19.
Correctly detect transparent proxy support on Linux hosts that require in.h to be included before netfilter_ipv4.h. Patch from coderman.
New TestingTorNetwork config option to allow adjustment of previously constant values that, while reasonable, could slow bootstrapping. Implements proposal 135. Patch from Karsten.
If you have more than one bridge but don't know their digests, you would only learn a request for the descriptor of the first one on your list. (Tor considered launching requests for the others, but found that it already had a connection on the way for $0000...0000 so it didn't open another.) Bugfix on 0.2.0.x.
If you have more than one bridge but don't know their digests, and the connection to one of the bridges failed, you would cancel all pending bridge connections. (After all, they all have the same digest.) Bugfix on 0.2.0.x.
When establishing a hidden service, introduction points that originate from cannibalized circuits are completely ignored and not included in rendezvous service descriptors. This might be another reason for delay in making a hidden service available. Bugfix from long ago (0.0.9.x?)
Allow OpenSSL to use dynamic locks if it wants.
When building a consensus, do not include routers that are down. This will cut down 30% to 40% on consensus size. Implements proposal 138.
In directory authorities' approved-routers files, allow fingerprints with or without space.
Add a "GETINFO /status/bootstrap-phase" controller option, so the controller can query our current bootstrap state in case it attaches partway through and wants to catch up.
Send an initial "Starting" bootstrap status event, so we have a state to start out in.
Asking for a conditional consensus at .../consensus/ would crash a dirserver if it did not already have a consensus. Bugfix on 0.2.1.1-alpha.
Clean up some macro/CPP interactions: some GCC versions don't like #if/#endif pairs inside macro arguments. Fixes bug 707. Bugfix on 0.2.0.x.
Directory authorities shouldn't complain about bootstrapping problems just because they do a lot of reachability testing and some of the connection attempts fail.
Start sending "count" and "recommendation" key/value pairs in bootstrap problem status events, so the controller can hear about problems even before Tor decides they're worth reporting for sure.
If you're using bridges, generate "bootstrap problem" warnings as soon as you run out of working bridges, rather than waiting for ten failures -- which will never happen if you have less than ten bridges.
If we close our OR connection because there's been a circuit pending on it for too long, we were telling our bootstrap status events "REASON=NONE". Now tell them "REASON=TIMEOUT".