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Diffstat (limited to 'libtommath/bn_mp_clamp.c')
| -rw-r--r-- | libtommath/bn_mp_clamp.c | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/libtommath/bn_mp_clamp.c b/libtommath/bn_mp_clamp.c new file mode 100644 index 0000000..da4e1ef --- /dev/null +++ b/libtommath/bn_mp_clamp.c @@ -0,0 +1,44 @@ +#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, tomstdenis@gmail.com, http://math.libtomcrypt.com + */ + +/* 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 + +/* $Source: /cvs/libtom/libtommath/bn_mp_clamp.c,v $ */ +/* $Revision: 1.3 $ */ +/* $Date: 2006/03/31 14:18:44 $ */ |