xref: /netbsd-src/crypto/external/bsd/heimdal/dist/lib/hcrypto/libtommath/bn_mp_and.c (revision d3273b5b76f5afaafe308cead5511dbb8df8c5e9)
1 /*	$NetBSD: bn_mp_and.c,v 1.2 2017/01/28 21:31:47 christos Exp $	*/
2 
3 #include <tommath.h>
4 #ifdef BN_MP_AND_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@gmail.com, http://libtom.org
18  */
19 
20 /* AND two ints together */
21 int
mp_and(mp_int * a,mp_int * b,mp_int * c)22 mp_and (mp_int * a, mp_int * b, mp_int * c)
23 {
24   int     res, ix, px;
25   mp_int  t, *x;
26 
27   if (a->used > b->used) {
28     if ((res = mp_init_copy (&t, a)) != MP_OKAY) {
29       return res;
30     }
31     px = b->used;
32     x = b;
33   } else {
34     if ((res = mp_init_copy (&t, b)) != MP_OKAY) {
35       return res;
36     }
37     px = a->used;
38     x = a;
39   }
40 
41   for (ix = 0; ix < px; ix++) {
42     t.dp[ix] &= x->dp[ix];
43   }
44 
45   /* zero digits above the last from the smallest mp_int */
46   for (; ix < t.used; ix++) {
47     t.dp[ix] = 0;
48   }
49 
50   mp_clamp (&t);
51   mp_exch (c, &t);
52   mp_clear (&t);
53   return MP_OKAY;
54 }
55 #endif
56 
57 /* Source: /cvs/libtom/libtommath/bn_mp_and.c,v  */
58 /* Revision: 1.4  */
59 /* Date: 2006/12/28 01:25:13  */
60