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Giac_maj/libtommath-0.39/bn_mp_and.c 1.27 KB
6663b6c9   adorian   projet complet av...
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  #include <tommath.h>
  #ifdef BN_MP_AND_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
   */
  
  /* AND two ints together */
  int
  mp_and (mp_int * a, mp_int * b, mp_int * c)
  {
    int     res, ix, px;
    mp_int  t, *x;
  
    if (a->used > b->used) {
      if ((res = mp_init_copy (&t, a)) != MP_OKAY) {
        return res;
      }
      px = b->used;
      x = b;
    } else {
      if ((res = mp_init_copy (&t, b)) != MP_OKAY) {
        return res;
      }
      px = a->used;
      x = a;
    }
  
    for (ix = 0; ix < px; ix++) {
      t.dp[ix] &= x->dp[ix];
    }
  
    /* zero digits above the last from the smallest mp_int */
    for (; ix < t.used; ix++) {
      t.dp[ix] = 0;
    }
  
    mp_clamp (&t);
    mp_exch (c, &t);
    mp_clear (&t);
    return MP_OKAY;
  }
  #endif
  
  /* $Source: /cvs/libtom/libtommath/bn_mp_and.c,v $ */
  /* $Revision: 1.3 $ */
  /* $Date: 2006/03/31 14:18:44 $ */