New alpha release: Tor 0.4.2.2-alpha

There's a new alpha release available for download. If you build Tor from source, you can download the source code for 0.4.2.2-alpha from the download page on the website. Packages should be available over the coming weeks, with a new alpha Tor Browser release likely in the next couple of weeks.

Remember, this is an alpha release: you should only run this if you'd like to find and report more bugs than usual.

This release fixes several bugs from the previous alpha release, and from earlier versions. It also includes a change in authorities, so that they begin to reject the currently unsupported release series.

Changes in version 0.4.2.2-alpha - 2019-10-07

• 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 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 (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.
• 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 (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.
• Minor features (geoip):
  • Update geoip and geoip6 to the October 1 2019 Maxmind GeoLite2 Country database. Closes ticket 31931.
• 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 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 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):
  • When listing overbroad exceptions, do not also list problems, and do not list insufficiently broad exceptions. Fixes bug 31338; bugfix on 0.4.2.1-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 (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.
• 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 (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 (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 (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.
• 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:
  • 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.