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Re: [kernel-hardening] Re: [PATCH v5 1/4] siphash: add cryptographically secure PRF

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On Fri, Dec 16, 2016, at 22:01, Jason A. Donenfeld wrote:
> Yes, on x86-64. But on i386 chacha20 incurs nearly the same kind of
> slowdown as siphash, so I expect the comparison to be more or less
> equal. There's another thing I really didn't like about your chacha20
> approach which is that it uses the /dev/urandom pool, which means
> various things need to kick in in the background to refill this.
> Additionally, having to refill the buffered chacha output every 32 or
> so longs isn't nice. These things together make for inconsistent and
> hard to understand general operating system performance, because
> get_random_long is called at every process startup for ASLR. So, in
> the end, I believe there's another reason for going with the siphash
> approach: deterministic performance.

*Hust*, so from where do you generate your key for siphash if called
early from ASLR?

Bye,
Hannes

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Re: [kernel-hardening] Re: [PATCH v5 1/4] siphash: add  cryptographically secure PRF "Jason A. Donenfeld" <Jason@zx2c4.com> - 2016-12-16 22:10 +0100
  Re: [kernel-hardening] Re: [PATCH v5 1/4] siphash: add cryptographically  secure PRF Hannes Frederic Sowa <hannes@stressinduktion.org> - 2016-12-16 22:20 +0100

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