1 #include <tommath.h> 2 #ifdef BN_MP_MOD_C 3 /* LibTomMath, multiple-precision integer library -- Tom St Denis 4 * 5 * LibTomMath is a library that provides multiple-precision 6 * integer arithmetic as well as number theoretic functionality. 7 * 8 * The library was designed directly after the MPI library by 9 * Michael Fromberger but has been written from scratch with 10 * additional optimizations in place. 11 * 12 * The library is free for all purposes without any express 13 * guarantee it works. 14 * 15 * Tom St Denis, tomstdenis (at) gmail.com, http://math.libtomcrypt.com 16 */ 17 18 /* c = a mod b, 0 <= c < b */ 19 int 20 mp_mod (mp_int * a, mp_int * b, mp_int * c) 21 { 22 mp_int t; 23 int res; 24 25 if ((res = mp_init (&t)) != MP_OKAY) { 26 return res; 27 } 28 29 if ((res = mp_div (a, b, NULL, &t)) != MP_OKAY) { 30 mp_clear (&t); 31 return res; 32 } 33 34 if (t.sign != b->sign) { 35 res = mp_add (b, &t, c); 36 } else { 37 res = MP_OKAY; 38 mp_exch (&t, c); 39 } 40 41 mp_clear (&t); 42 return res; 43 } 44 #endif 45 46 /* $Source: /cvs/libtom/libtommath/bn_mp_mod.c,v $ */ 47 /* $Revision: 1.3 $ */ 48 /* $Date: 2006/03/31 14:18:44 $ */ 49
