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comparison libtommath/bn_mp_neg.c @ 285:1b9e69c058d2

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propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3) to branch 'au.asn.ucc.matt.dropbear' (head fdf4a7a3b97ae5046139915de7e40399cceb2c01)
author Matt Johnston <matt@ucc.asn.au>
date Wed, 08 Mar 2006 13:23:58 +0000
parents eed26cff980b
children 5ff8218bcee9
comparison
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281:997e6f7dc01e 285:1b9e69c058d2
1 #include <tommath.h>
2 #ifdef BN_MP_NEG_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 /* b = -a */
19 int mp_neg (mp_int * a, mp_int * b)
20 {
21 int res;
22 if (a != b) {
23 if ((res = mp_copy (a, b)) != MP_OKAY) {
24 return res;
25 }
26 }
27
28 if (mp_iszero(b) != MP_YES) {
29 b->sign = (a->sign == MP_ZPOS) ? MP_NEG : MP_ZPOS;
30 } else {
31 b->sign = MP_ZPOS;
32 }
33
34 return MP_OKAY;
35 }
36 #endif