comparison libtommath/bn_mp_neg.c @ 297:79bf1023cf11 agent-client

propagate from branch 'au.asn.ucc.matt.dropbear' (head 0501e6f661b5415eb76f3b312d183c3adfbfb712) to branch 'au.asn.ucc.matt.dropbear.cli-agent' (head 01038174ec27245b51bd43a66c01ad930880f67b)
author Matt Johnston <matt@ucc.asn.au>
date Tue, 21 Mar 2006 16:20:59 +0000
parents eed26cff980b
children 5ff8218bcee9
comparison
equal deleted inserted replaced
225:ca7e76d981d9 297:79bf1023cf11
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