/* $NetBSD: bn_mp_mod.c,v 1.2 2017/01/28 21:31:47 christos Exp $ */ #include <tommath.h> #ifdef BN_MP_MOD_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://libtom.org */ /* c = a mod b, 0 <= c < b if b > 0, b < c <= 0 if b < 0 */ int mp_mod (mp_int * a, mp_int * b, mp_int * c) { mp_int t; int res; if ((res = mp_init (&t)) != MP_OKAY) { return res; } if ((res = mp_div (a, b, NULL, &t)) != MP_OKAY) { mp_clear (&t); return res; } if (mp_iszero(&t) || t.sign == b->sign) { res = MP_OKAY; mp_exch (&t, c); } else { res = mp_add (b, &t, c); } mp_clear (&t); return res; } #endif /* Source: /cvs/libtom/libtommath/bn_mp_mod.c,v */ /* Revision: 1.4 */ /* Date: 2006/12/28 01:25:13 */ |