1#include <tommath.h>
2#ifdef BN_MP_SUBMOD_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://libtom.org
16 */
17
18/* d = a - b (mod c) */
19int
20mp_submod (mp_int * a, mp_int * b, mp_int * c, mp_int * d)
21{
22  int     res;
23  mp_int  t;
24
25
26  if ((res = mp_init (&t)) != MP_OKAY) {
27    return res;
28  }
29
30  if ((res = mp_sub (a, b, &t)) != MP_OKAY) {
31    mp_clear (&t);
32    return res;
33  }
34  res = mp_mod (&t, c, d);
35  mp_clear (&t);
36  return res;
37}
38#endif
39
40/* $Source$ */
41/* $Revision$ */
42/* $Date$ */
43