On 11/05/09 15:52, Nick Mathewson wrote: > On Thu, Nov 05, 2009 at 02:10:00PM -0500, Marcus Griep wrote: >> Don't know if any one else has seen or taken a look at this. I don't know if >> this affects Tor, though I believe that we do use certificate renegotiation >> in the protocol, and that is the entry vector for this particular >> vulnerability: > > FWIW, this doesn't affect Tor. The problem here is not renegotiation > per se; the problem is doing renegotiation, then acting as though data > sent _before_ the renegotiation were authenticated with the > rengotiated credentials. > > The Tor protocol isn't vulnerable here because 1) it doesn't allow data > to be sent before the renegotiation step, and 2) it doesn't treat a > renegotiation as authenticating previously exchanged data (because > there isn't any).
The vulnerability itself might not effect Tor, but the OpenSSL workaround for this vulnerability of disabling renegotiation by default in 0.9.8l [1] might not play nice with a Tor implementation. -Andrew [1] http://www.openssl.org/news/secadv_20091111.txt *********************************************************************** To unsubscribe, send an e-mail to [email protected] with unsubscribe or-talk in the body. http://archives.seul.org/or/talk/
