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Giac_maj/libtommath-0.39/bn_mp_to_unsigned_bin.c 1.23 KB
6663b6c9   adorian   projet complet av...
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  #include <tommath.h>
  #ifdef BN_MP_TO_UNSIGNED_BIN_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
   */
  
  /* store in unsigned [big endian] format */
  int mp_to_unsigned_bin (mp_int * a, unsigned char *b)
  {
    int     x, res;
    mp_int  t;
  
    if ((res = mp_init_copy (&t, a)) != MP_OKAY) {
      return res;
    }
  
    x = 0;
    while (mp_iszero (&t) == 0) {
  #ifndef MP_8BIT
        b[x++] = (unsigned char) (t.dp[0] & 255);
  #else
        b[x++] = (unsigned char) (t.dp[0] | ((t.dp[1] & 0x01) << 7));
  #endif
      if ((res = mp_div_2d (&t, 8, &t, NULL)) != MP_OKAY) {
        mp_clear (&t);
        return res;
      }
    }
    bn_reverse (b, x);
    mp_clear (&t);
    return MP_OKAY;
  }
  #endif
  
  /* $Source: /cvs/libtom/libtommath/bn_mp_to_unsigned_bin.c,v $ */
  /* $Revision: 1.3 $ */
  /* $Date: 2006/03/31 14:18:44 $ */