Open Stack

Hi, I'd like you to take a look at this patch for potential
SecurityImpact.
https://review.openstack.org/80398

Log:
commit dde7670369cc8cbc3fe1633935eeab218b93ea17
Author: Brant Knudson <bknudson at us.ibm.com>
Date:   Thu Mar 13 15:38:34 2014 -0500

    Allow hash tokens with sha256
    
    Tokens were always hashed with md5. This change allows tokens to
    be hashed with sha256 or any other algorithm supported by hashlib.
    This is for security hardening.
    
    If the new 'hash_algorithm' configuration option is set to 'sha256'
    then the auth_token middleware will hash tokens using 'sha256' when
    
    a) Tokens are stored to the cache.
    b) Tokens are hashed to compare against the revocation list.
    
    Using this will require that the Keystone server is also configured
    to use the same algorithm for tokens, otherwise the revocation list
    comparison isn't going to work. The 'hash_algorithm' option defaults
    to 'md5' for backwards compatibility.
    
    SecurityImpact
    DocImpact
    Closes-Bug: #1174499
    
    Change-Id: Ie524125dc5f6f1076bfd47db3a414b178e4dac80