view libtommath/bn_mp_and.c @ 1682:a53e7d2d60be

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author Matt Johnston <matt@ucc.asn.au>
date Mon, 25 May 2020 20:23:02 +0800
parents f52919ffd3b1
children 1051e4eea25a
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#include "tommath_private.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.
 *
 * SPDX-License-Identifier: Unlicense
 */

/* AND two ints together */
int mp_and(const mp_int *a, const mp_int *b, mp_int *c)
{
   int     res, ix, px;
   mp_int  t;
   const mp_int *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

/* ref:         HEAD -> master, tag: v1.1.0 */
/* git commit:  08549ad6bc8b0cede0b357a9c341c5c6473a9c55 */
/* commit time: 2019-01-28 20:32:32 +0100 */