Mercurial > dropbear
view bn_mp_clamp.c @ 163:8e94663164c6 libtommath LTM_DB_0.44
make pointers volatile so that memory zeroing won't get optimised away
author | Matt Johnston <matt@ucc.asn.au> |
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date | Sun, 02 Jan 2005 17:09:26 +0000 |
parents | d29b64170cf0 |
children |
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#include <tommath.h> #ifdef BN_MP_CLAMP_C /* LibTomMath, multiple-precision integer library -- Tom St Denis * * LibTomMath is a library that provides multiple-precision * integer arithmetic as well as number theoretic functionality. * * The library was designed directly after the MPI library by * Michael Fromberger but has been written from scratch with * additional optimizations in place. * * The library is free for all purposes without any express * guarantee it works. * * Tom St Denis, [email protected], http://math.libtomcrypt.org */ /* trim unused digits * * This is used to ensure that leading zero digits are * trimed and the leading "used" digit will be non-zero * Typically very fast. Also fixes the sign if there * are no more leading digits */ void mp_clamp (mp_int * a) { /* decrease used while the most significant digit is * zero. */ while (a->used > 0 && a->dp[a->used - 1] == 0) { --(a->used); } /* reset the sign flag if used == 0 */ if (a->used == 0) { a->sign = MP_ZPOS; } } #endif