[Python-Dev] Status of the fix for the hash collision vulnerability

[Gregory P. Smith]

btw, Tim's commit message on this one is amusingly relevant. :)

 http://hg.python.org/cpython/diff/8d2bbbbf2cb9/Objects/dictobject.c


On Fri, Jan 13, 2012 at 6:25 PM, Gregory P. Smith <greg at krypto.org> wrote:

>
>> Clearly these ideas are more complex than adding randomization, but
>> adding randomization doesn't seem to be produce immunity from attack, when
>> data about the randomness is leaked.
>>
>
> Which will not normally happen.
>
> I'm firmly in the camp that believes the random seed can be probed and
> determined by creatively injecting values and measuring timing of things.
>  But doing that is difficult and time and bandwidth intensive so the per
> process random hash seed is good enough.
>
> There's another elephant in the room here, if you want to avoid this
> attack use a 64-bit Python build as it uses 64-bit hash values that are
> significantly more difficult to force a collision on.
>
> -gps
>
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