Mercurial > dropbear
view libtommath/bn_mp_invmod.c @ 310:4b4478d0d2b9 ucc-axis-hack
add a comment on usage
author | Matt Johnston <matt@ucc.asn.au> |
---|---|
date | Sun, 26 Mar 2006 08:28:16 +0000 |
parents | eed26cff980b |
children | 5ff8218bcee9 |
line wrap: on
line source
#include <tommath.h> #ifdef BN_MP_INVMOD_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 */ /* hac 14.61, pp608 */ int mp_invmod (mp_int * a, mp_int * b, mp_int * c) { /* b cannot be negative */ if (b->sign == MP_NEG || mp_iszero(b) == 1) { return MP_VAL; } #ifdef BN_FAST_MP_INVMOD_C /* if the modulus is odd we can use a faster routine instead */ if (mp_isodd (b) == 1) { return fast_mp_invmod (a, b, c); } #endif #ifdef BN_MP_INVMOD_SLOW_C return mp_invmod_slow(a, b, c); #endif return MP_VAL; } #endif