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      1 /*	$NetBSD: bn_mp_reduce_setup.c,v 1.2 2017/01/28 21:31:47 christos Exp $	*/
      2 
      3 #include <tommath.h>
      4 #ifdef BN_MP_REDUCE_SETUP_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 /* pre-calculate the value required for Barrett reduction
     21  * For a given modulus "b" it calulates the value required in "a"
     22  */
     23 int mp_reduce_setup (mp_int * a, mp_int * b)
     24 {
     25   int     res;
     26 
     27   if ((res = mp_2expt (a, b->used * 2 * DIGIT_BIT)) != MP_OKAY) {
     28     return res;
     29   }
     30   return mp_div (a, b, a, NULL);
     31 }
     32 #endif
     33 
     34 /* Source: /cvs/libtom/libtommath/bn_mp_reduce_setup.c,v  */
     35 /* Revision: 1.4  */
     36 /* Date: 2006/12/28 01:25:13  */
     37