Open Stack

Hi, I'd like you to take a look at this patch for potential
SecurityImpact.
https://review.openstack.org/116509

Log:
commit ed1e31eca6cd34677feb6674973c4f8989b2b4e4
Author: Brant Knudson <bknudson at us.ibm.com>
Date:   Sat Aug 23 11:35:25 2014 -0500

    Configurable token hashing algorithm
    
    The user's authentication token was hashed using the MD5 algorithm.
    The MD5 algorithm shouldn't be used because of the potential for
    hash collisions. Some security standards mandate a SHA2 algorithm
    or better must be used.
    
    With this change the algorithm to use for hashing tokens can be
    configured by setting the OPENSTACK_TOKEN_HASH_ALGORITHM
    configuration option to a hash algorithm supported by Python's
    hashlib library[1]. For example, a deployer could set the option to
    'sha256' to meet a SHA2 security standard.
    
    The algorithm chosen must match the hash algorithm that the
    identity server is configured to use (Keystone and the auth_token
    middleware can be configured to use any hash algorithm supported by
    hashlib).
    
    This is for security hardening.
    
    [1] https://docs.python.org/2/library/hashlib.html
    
    DocImpact
    SecurityImpact
    
    Change-Id: I9e3eba7e0a12ae40a08d0ed851ea916ec6591bcc
    Closes-Bug: #1174499