Messages in this thread | | | Date | Mon, 11 Feb 2013 10:37:45 -0800 | From | Andy Lutomirski <> | Subject | Re: [PATCH] lib: memcmp_nta: add timing-attack secure memcmp |
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On 02/10/2013 02:00 PM, Daniel Borkmann wrote: > If you need to compare a password or a hash value, the timing of the > comparison function can give valuable clues to the attacker. Let's > say the password is 123456 and the attacker tries abcdef. If the > comparision function fails at the first byte without looking at the > other bytes, then the attacker can measure the difference in runtime > and deduce which byte was wrong, reducing the attack space from > exponential to polynomial. [Daniel J. Bernstein] > > Therefore add memcmp_nta ({n}o {t}iming {a}ttacks) in order to avoid > such scenarios and to facilitate development by providing a generic > function for (e.g.) the crypto and networking subsystems. > > Signed-off-by: Daniel Borkmann <dborkman@redhat.com> > ---
I read this as "compare memory with non-temporal access". Perhaps something like "memcpy_constant_time" would be less confusing.
--Andy
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