[tor-talk] Tor 0.4.2.3-alpha is released

[Nick Mathewson]

Hi, all!

There's a new alpha Tor release! Because it's an alpha, you should
only run it if you're ready to find more bugs than usual, and report
them on trac.torproject.org.

The source code is available from the usual place on
www.torproject.org; if you build Tor from source, why not give it a
try? And if you don't build Tor from source, packages should be ready
over the coming days, with a Tor Browser alpha release likely in a
couple of weeks.

Here's what's new:

Changes in version 0.4.2.3-alpha - 2019-10-24
  This release fixes several bugs from the previous alpha release, and
  from earlier versions of Tor.

  o 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.

  o 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.

  o 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.

  o 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.

  o 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.

  o 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.

  o 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.

  o Minor bugfixes (error handling):
    - Always lock the backtrace buffer before it is used. Fixes bug
      31734; bugfix on 0.2.5.3-alpha.

  o 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.

  o 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.

  o 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.

  o 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.

  o Minor bugfixes (v3 onion services):
    - Fix an implicit conversion from ssize_t to size_t discovered by
      Coverity. Fixes bug 31682; bugfix on 0.4.2.1-alpha.
    - Fix a memory leak in an unlikely error code path when encoding HS
      DoS establish intro extension cell. Fixes bug 32063; bugfix
      on 0.4.2.1-alpha.
    - 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.

  o 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.