crypto/external/bsd/heimdal/dist/lib/hcrypto/libtommath/bn_mp_submod.c

   1 /*      $NetBSD: bn_mp_submod.c,v 1.1.1.2 2014/04/24 12:45:31 pettai Exp $      */
   2
   3 #include <tommath.h>
   4 #ifdef BN_MP_SUBMOD_C
   5 /* LibTomMath, multiple-precision integer library -- Tom St Denis
   6  *
   7  * LibTomMath is a library that provides multiple-precision
   8  * integer arithmetic as well as number theoretic functionality.
   9  *
  10  * The library was designed directly after the MPI library by
  11  * Michael Fromberger but has been written from scratch with
  12  * additional optimizations in place.
  13  *
  14  * The library is free for all purposes without any express
  15  * guarantee it works.
  16  *
  17  * Tom St Denis, tomstdenis@gmail.com, http://libtom.org
  18  */
  19
  20 /* d = a - b (mod c) */
  21 int
  22 mp_submod (mp_int * a, mp_int * b, mp_int * c, mp_int * d)
  23 {
  24   int     res;
  25   mp_int  t;
  26
  27
  28   if ((res = mp_init (&t)) != MP_OKAY) {
  29     return res;
  30   }
  31
  32   if ((res = mp_sub (a, b, &t)) != MP_OKAY) {
  33     mp_clear (&t);
  34     return res;
  35   }
  36   res = mp_mod (&t, c, d);
  37   mp_clear (&t);
  38   return res;
  39 }
  40 #endif
  41
  42 /* Source: /cvs/libtom/libtommath/bn_mp_submod.c,v  */
  43 /* Revision: 1.4  */
  44 /* Date: 2006/12/28 01:25:13  */