W3C home > Mailing lists > Public > public-webappsec@w3.org > May 2015

Logjam and Resetting Handshake Timers in Browsers

From: Jeffrey Walton <noloader@gmail.com>
Date: Thu, 21 May 2015 14:49:21 -0400
Message-ID: <CAH8yC8mQDySRKZW6yF5WD+Z6hDQTpAv2G5XysGdU-N5vXpXKqw@mail.gmail.com>
To: "public-webappsec@w3.org" <public-webappsec@w3.org>
The logjam paper is available at
https://weakdh.org/imperfect-forward-secrecy.pdf.

Note that the authors were successful in exploiting it in browsers
because they could send an alert warning to reset the handshake timer.
Cf., page 5.

Is this desired behavior?

I generally use 2-MSL as the "rule of thumb" to determine how long an
attacker has to tamper with things. If its possible to use these sorts
of out of band messages to reset timers, then it probably has a
negative effect on the security of the system.

Jeff
Received on Thursday, 21 May 2015 18:49:48 UTC

This archive was generated by hypermail 2.3.1 : Monday, 23 October 2017 14:54:13 UTC