Make Tor work with OpenSSL 0.9.8l

To fix a major security problem related to incorrect use of
SSL/TLS renegotiation, OpenSSL has turned off renegotiation by
default.  We are not affected by this security problem, however,
since we do renegotiation right.  (Specifically, we never treat a
renegotiated credential as authenticating previous communication.)
Nevertheless, OpenSSL's new behavior requires us to explicitly
turn renegotiation back on in order to get our protocol working
again.

Amusingly, this is not so simple as "set the flag when you create
the SSL object" , since calling connect or accept seems to clear
the flags.

For belt-and-suspenders purposes, we clear the flag once the Tor
handshake is done.  There's no way to exploit a second handshake
either, but we might as well not allow it.

1 files changed, 6 insertions, 0 deletions

diff --git a/ChangeLog b/ChangeLog
index 7023ea3bbe..4799e74078 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,4 +1,10 @@
 Changes in Version 0.2.1.21 - 20??-??-??
+  o 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.
+
   o Minor bugfixes:
     - Do not refuse to learn about authority certs and v2 networkstatus
       documents that are older than the latest consensus.  This bug might