view libtommath/bn_mp_mod.c @ 1692:1051e4eea25a

Update LibTomMath to 1.2.0 (#84) * update C files * update other files * update headers * update makefiles * remove mp_set/get_double() * use ltm 1.2.0 API * update ltm_desc * use bundled tommath if system-tommath is too old * XMALLOC etc. were changed to MP_MALLOC etc.
author Steffen Jaeckel <s@jaeckel.eu>
date Tue, 26 May 2020 17:36:47 +0200
parents f52919ffd3b1
children
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#include "tommath_private.h"
#ifdef BN_MP_MOD_C
/* LibTomMath, multiple-precision integer library -- Tom St Denis */
/* SPDX-License-Identifier: Unlicense */

/* c = a mod b, 0 <= c < b if b > 0, b < c <= 0 if b < 0 */
mp_err mp_mod(const mp_int *a, const mp_int *b, mp_int *c)
{
   mp_int  t;
   mp_err  err;

   if ((err = mp_init_size(&t, b->used)) != MP_OKAY) {
      return err;
   }

   if ((err = mp_div(a, b, NULL, &t)) != MP_OKAY) {
      goto LBL_ERR;
   }

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

LBL_ERR:
   mp_clear(&t);
   return err;
}
#endif