Author dmalcolm
Recipients Arach, Arfrever, Huzaifa.Sidhpurwala, Jim.Jewett, Mark.Shannon, PaulMcMillan, Zhiping.Deng, alex, barry, benjamin.peterson, christian.heimes, dmalcolm, eric.araujo, eric.snow, fx5, georg.brandl, grahamd, gregory.p.smith, gvanrossum, gz, jcea, lemburg, mark.dickinson, neologix, pitrou, skrah, terry.reedy, tim.peters, v+python, vstinner, zbysz
Date 2012-01-23.04:04:41
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I arbitrarily started with 50, and then decided a power of two would be
quicker when multiplying.  There wasn't any rigorous analysis behind the
choice of factor.

Though, as noted in msg151796, I've gone off this idea, since I think
the "protection" creates additional avenues of attack.

I think getting some kind of hash randomization patch into the hands of
users ASAP is the way forward here (even if disabled by default).

If we're going to support shipping backported versions of the hash
randomization patch with the randomization disabled, did we decide on a
way of enabling it?  If not, then I propose that those who want to ship
with it disabled by default standardize on (say):


as an environment variable: if set to nonzero, it enables hash
randomization (reading the random seed as per the 3.3. patch, and
respecting the PYTHONHASHSEED variable if that's also set).  If set to
zero or not present, hash randomization is disabled.

Does that sound sane?

(we can't use PYTHONHASHSEED for this, since if a number is given, that
means "use this number", right?)

FWIW, I favor hash randomization in 2.* for PyStringObject,
PyUnicodeObject, PyBufferObject, and the 3 datetime classes in
Modules/_datetimemodule.c (see the implementation of generic_hash in
that file), but to not do it for the numeric types.

Sorry; I only tried it on the python test suite (and on a set of
reproducers for the DoS that I've written for RH's in-house test suite).
Date User Action Args
2012-01-23 04:04:43dmalcolmsetrecipients: + dmalcolm, lemburg, gvanrossum, tim.peters, barry, georg.brandl, terry.reedy, gregory.p.smith, jcea, mark.dickinson, pitrou, vstinner, christian.heimes, benjamin.peterson, eric.araujo, grahamd, Arfrever, v+python, alex, zbysz, skrah, gz, neologix, Arach, Mark.Shannon, eric.snow, Zhiping.Deng, Huzaifa.Sidhpurwala, Jim.Jewett, PaulMcMillan, fx5
2012-01-23 04:04:42dmalcolmlinkissue13703 messages
2012-01-23 04:04:41dmalcolmcreate