Mercurial > dropbear

comparison libtommath/bn_mp_and.c @ 330:5488db2e9e4e

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
merge of 332f709a4cb39cde4cedab7c3be89e05f3023067 and ca4ca78b82c5d430c69ce01bf794e8886ce81431
author Matt Johnston <matt@ucc.asn.au>
date Sat, 10 Jun 2006 16:39:40 +0000
parents eed26cff980b
children 5ff8218bcee9
comparison
equal deleted inserted replaced
329:8ed0dce45126 330:5488db2e9e4e
1 #include <tommath.h>
2 #ifdef BN_MP_AND_C
3 /* LibTomMath, multiple-precision integer library -- Tom St Denis
4 *
5 * LibTomMath is a library that provides multiple-precision
6 * integer arithmetic as well as number theoretic functionality.
7 *
8 * The library was designed directly after the MPI library by
9 * Michael Fromberger but has been written from scratch with
10 * additional optimizations in place.
11 *
12 * The library is free for all purposes without any express
13 * guarantee it works.
14 *
15 * Tom St Denis, [email protected], http://math.libtomcrypt.org
16 */
17
18 /* AND two ints together */
19 int
20 mp_and (mp_int * a, mp_int * b, mp_int * c)
21 {
22 int res, ix, px;
23 mp_int t, *x;
24
25 if (a->used > b->used) {
26 if ((res = mp_init_copy (&t, a)) != MP_OKAY) {
27 return res;
28 }
29 px = b->used;
30 x = b;
31 } else {
32 if ((res = mp_init_copy (&t, b)) != MP_OKAY) {
33 return res;
34 }
35 px = a->used;
36 x = a;
37 }
38
39 for (ix = 0; ix < px; ix++) {
40 t.dp[ix] &= x->dp[ix];
41 }
42
43 /* zero digits above the last from the smallest mp_int */
44 for (; ix < t.used; ix++) {
45 t.dp[ix] = 0;
46 }
47
48 mp_clamp (&t);
49 mp_exch (c, &t);
50 mp_clear (&t);
51 return MP_OKAY;
52 }
53 #endif