Mercurial > dropbear
view bn_mp_clamp.c @ 283:bd240aa12ba7 libtommath-dropbear
* Changes imported from Dropbear 0.47.
* bn_mp_clear.c is changed so that some vars are volatile,
so that the compiler won't optimise away
author | Matt Johnston <matt@ucc.asn.au> |
---|---|
date | Wed, 08 Mar 2006 13:22:52 +0000 |
parents | 91fbc376f010 |
children | 97db060d0ef5 |
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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