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Re: CVS commit: src

   Date: Thu, 30 Aug 2012 19:51:13 +0100
   From: David Laight <>

   FWIW which versions of memset() aren't 'constant time' ?
   Apart from ones that try not to dirty pages.

The issue with memset isn't timing attacks, but rather that the C
compiler is likely to optimize away the apparently useless memset from
code that looks like this, and thereby leave keys floating about in

        char key[32];

        memset(key, 0, sizeof key);

Hence explicit_{bzero,memset}, not consttime_{bzero,memset}, which are
supposed to be guaranteed not to be optimized away.

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