afflux/pure-python-otr — pull request #52 by mmb (2014-05-02 20:06:29+00:00)
Title: Make sure AES key is always 16 bytes.

Once in a while the key was less than 16 bytes due to leading zeros
causing pycrypto to raise an exception.

See https://bugs.launchpad.net/pycrypto/+bug/1276431

Bug identified and fix suggested by Legrandin.