### comparison libtommath/bn_mp_xor.c @ 389:5ff8218bcee9

author Matt Johnston Thu, 11 Jan 2007 03:14:55 +0000 eed26cff980b 60fc6476e044
comparison
equal inserted replaced
388:fb54020f78e1 389:5ff8218bcee9
1 #include <tommath.h>
2 #ifdef BN_MP_XOR_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.com
16 */
17
18 /* XOR two ints together */
19 int
20 mp_xor (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 mp_clamp (&t);
43 mp_exch (c, &t);
44 mp_clear (&t);
45 return MP_OKAY;
46 }
47 #endif
48
49 /* \$Source: /cvs/libtom/libtommath/bn_mp_xor.c,v \$ */
50 /* \$Revision: 1.3 \$ */
51 /* \$Date: 2006/03/31 14:18:44 \$ */