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Giac_maj/libtommath-0.39/bn_mp_reduce_setup.c 1011 Bytes
6663b6c9   adorian   projet complet av...
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  #include <tommath.h>
  #ifdef BN_MP_REDUCE_SETUP_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, tomstdenis@gmail.com, http://math.libtomcrypt.com
   */
  
  /* pre-calculate the value required for Barrett reduction
   * For a given modulus "b" it calulates the value required in "a"
   */
  int mp_reduce_setup (mp_int * a, mp_int * b)
  {
    int     res;
    
    if ((res = mp_2expt (a, b->used * 2 * DIGIT_BIT)) != MP_OKAY) {
      return res;
    }
    return mp_div (a, b, a, NULL);
  }
  #endif
  
  /* $Source: /cvs/libtom/libtommath/bn_mp_reduce_setup.c,v $ */
  /* $Revision: 1.3 $ */
  /* $Date: 2006/03/31 14:18:44 $ */