view bn_mp_mod.c @ 387:4663ced4968f libtommath-dropbear

propagate from branch 'au.asn.ucc.matt.ltm.orig' (head 1c2b7d389d0682caf980235dad97493e3206389c) to branch 'au.asn.ucc.matt.ltm.dropbear' (head 40ab3795de3a6157f34e52ed3f0be3eebe9a2eaa)
author Matt Johnston <matt@ucc.asn.au>
date Thu, 11 Jan 2007 03:13:04 +0000
parents 97db060d0ef5
children
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#include <tommath.h>
#ifdef BN_MP_MOD_C
/* LibTomMath, multiple-precision integer library -- Tom St Denis
 *
 * LibTomMath is a library that provides multiple-precision
 * integer arithmetic as well as number theoretic functionality.
 *
 * The library was designed directly after the MPI library by
 * Michael Fromberger but has been written from scratch with
 * additional optimizations in place.
 *
 * The library is free for all purposes without any express
 * guarantee it works.
 *
 * Tom St Denis, [email protected], http://math.libtomcrypt.com
 */

/* c = a mod b, 0 <= c < b */
int
mp_mod (mp_int * a, mp_int * b, mp_int * c)
{
  mp_int  t;
  int     res;

  if ((res = mp_init (&t)) != MP_OKAY) {
    return res;
  }

  if ((res = mp_div (a, b, NULL, &t)) != MP_OKAY) {
    mp_clear (&t);
    return res;
  }

  if (t.sign != b->sign) {
    res = mp_add (b, &t, c);
  } else {
    res = MP_OKAY;
    mp_exch (&t, c);
  }

  mp_clear (&t);
  return res;
}
#endif

/* $Source: /cvs/libtom/libtommath/bn_mp_mod.c,v $ */
/* $Revision: 1.3 $ */
/* $Date: 2006/03/31 14:18:44 $ */