Tor 0.2.1.26-stable released

Tor 0.2.1.26 addresses the recent connection and memory overload problems we've been seeing on relays, especially relays with their DirPort open. If your relay has been crashing, or you turned it off because it used too many resources, give this release a try.

This release also fixes yet another instance of broken OpenSSL libraries that was causing some relays to drop out of the consensus.

Available for download at https://www.torproject.org/easy-download

Changes in version 0.2.1.26
Major bugfixes:

• Teach relays to defend themselves from connection overload. Relays
  now close idle circuits early if it looks like they were intended
  for directory fetches. Relays are also more aggressive about closing
  TLS connections that have no circuits on them. Such circuits are
  unlikely to be re-used, and tens of thousands of them were piling
  up at the fast relays, causing the relays to run out of sockets
  and memory. Bugfix on 0.2.0.22-rc (where clients started tunneling
  their directory fetches over TLS).
• Fix SSL renegotiation behavior on OpenSSL versions like on Centos
  that claim to be earlier than 0.9.8m, but which have in reality
  backported huge swaths of 0.9.8m or 0.9.8n renegotiation
  behavior. Possible fix for some cases of bug 1346.
• Directory mirrors were fetching relay descriptors only from v2
  directory authorities, rather than v3 authorities like they should.
  Only 2 v2 authorities remain (compared to 7 v3 authorities), leading
  to a serious bottleneck. Bugfix on 0.2.0.9-alpha. Fixes bug 1324.

Minor bugfixes:

• Finally get rid of the deprecated and now harmful notion of "clique
  mode", where directory authorities maintain TLS connections to
  every other relay.

Testsuite fixes:

• In the util/threads test, no longer free the test_mutex before all
  worker threads have finished. Bugfix on 0.2.1.6-alpha.
• The master thread could starve the worker threads quite badly on
  certain systems, causing them to run only partially in the allowed
  window. This resulted in test failures. Now the master thread sleeps
  occasionally for a few microseconds while the two worker-threads
  compete for the mutex. Bugfix on 0.2.0.1-alpha.