Messages in this thread | | | Date | Wed, 6 May 2009 12:57:17 -0500 | From | Matt Mackall <> | Subject | Re: [Security] [PATCH] proc: avoid information leaks to non-privileged processes |
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On Wed, May 06, 2009 at 09:48:20AM -0700, Linus Torvalds wrote: > > Matt, are you willing to ack my suggested patch which adds history to the > mix? Did somebody test that? I have this memory of there being an > "exploit" program to show the non-randomness of the values, but I can't > recall details, and would really want to get a second opinion from > somebody who cares about PRNG's.
I still don't like it. I bounced it off some folks on the adversarial side of things and they didn't think it looked strong enough either. Full MD5 collisions can be generated about as fast as they can be checked, which makes _reduced strength_ MD4 not much better than an LFSR in terms of attack potential. So I suggest we either:
a) take my original patch b) respin your patch using at least SHA1 rather than halfMD4 and changing the name to get_random_u32
If you'd prefer (b), I'll do the legwork.
-- Mathematics is the supreme nostalgia of our time.
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