release/src/router/dropbear/libtommath/bn_mp_mulmod.c

   1 #include <tommath.h>
   2 #ifdef BN_MP_MULMOD_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@gmail.com, http://math.libtomcrypt.com
  16  */
  17
  18 /* d = a * b (mod c) */
  19 int mp_mulmod (mp_int * a, mp_int * b, mp_int * c, mp_int * d)
  20 {
  21   int     res;
  22   mp_int  t;
  23
  24   if ((res = mp_init_size (&t, c->used)) != MP_OKAY) {
  25     return res;
  26   }
  27
  28   if ((res = mp_mul (a, b, &t)) != MP_OKAY) {
  29     mp_clear (&t);
  30     return res;
  31   }
  32   res = mp_mod (&t, c, d);
  33   mp_clear (&t);
  34   return res;
  35 }
  36 #endif
  37
  38 /* $Source: /cvs/libtom/libtommath/bn_mp_mulmod.c,v $ */
  39 /* $Revision: 1.4 $ */
  40 /* $Date: 2006/03/31 14:18:44 $ */