1#include <tommath.h>
2#ifdef BN_MP_INVMOD_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/* hac 14.61, pp608 */
19int mp_invmod (mp_int * a, mp_int * b, mp_int * c)
20{
21  /* b cannot be negative */
22  if (b->sign == MP_NEG || mp_iszero(b) == 1) {
23    return MP_VAL;
24  }
25
26#ifdef BN_FAST_MP_INVMOD_C
27  /* if the modulus is odd we can use a faster routine instead */
28  if (mp_isodd (b) == 1) {
29    return fast_mp_invmod (a, b, c);
30  }
31#endif
32
33#ifdef BN_MP_INVMOD_SLOW_C
34  return mp_invmod_slow(a, b, c);
35#else
36  return MP_VAL;
37#endif
38}
39#endif
40
41/* $Source: /cvs/libtom/libtommath/bn_mp_invmod.c,v $ */
42/* $Revision: 1.4 $ */
43/* $Date: 2006/12/28 01:25:13 $ */
44