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      1 /*	$NetBSD: bn_mp_mod.c,v 1.2 2017/01/28 21:31:47 christos Exp $	*/
      2 
      3 #include <tommath.h>
      4 #ifdef BN_MP_MOD_C
      5 /* LibTomMath, multiple-precision integer library -- Tom St Denis
      6  *
      7  * LibTomMath is a library that provides multiple-precision
      8  * integer arithmetic as well as number theoretic functionality.
      9  *
     10  * The library was designed directly after the MPI library by
     11  * Michael Fromberger but has been written from scratch with
     12  * additional optimizations in place.
     13  *
     14  * The library is free for all purposes without any express
     15  * guarantee it works.
     16  *
     17  * Tom St Denis, tomstdenis (at) gmail.com, http://libtom.org
     18  */
     19 
     20 /* c = a mod b, 0 <= c < b if b > 0, b < c <= 0 if b < 0 */
     21 int
     22 mp_mod (mp_int * a, mp_int * b, mp_int * c)
     23 {
     24   mp_int  t;
     25   int     res;
     26 
     27   if ((res = mp_init (&t)) != MP_OKAY) {
     28     return res;
     29   }
     30 
     31   if ((res = mp_div (a, b, NULL, &t)) != MP_OKAY) {
     32     mp_clear (&t);
     33     return res;
     34   }
     35 
     36   if (mp_iszero(&t) || t.sign == b->sign) {
     37     res = MP_OKAY;
     38     mp_exch (&t, c);
     39   } else {
     40     res = mp_add (b, &t, c);
     41   }
     42 
     43   mp_clear (&t);
     44   return res;
     45 }
     46 #endif
     47 
     48 /* Source: /cvs/libtom/libtommath/bn_mp_mod.c,v  */
     49 /* Revision: 1.4  */
     50 /* Date: 2006/12/28 01:25:13  */
     51