comparison libtommath/bn_mp_neg.c @ 284:eed26cff980b

propagate from branch 'au.asn.ucc.matt.ltm.dropbear' (head 6c790cad5a7fa866ad062cb3a0c279f7ba788583) to branch 'au.asn.ucc.matt.dropbear' (head fff0894a0399405a9410ea1c6d118f342cf2aa64)
author Matt Johnston <matt@ucc.asn.au>
date Wed, 08 Mar 2006 13:23:49 +0000
parents
children 5ff8218bcee9
comparison
equal deleted inserted replaced
283:bd240aa12ba7 284:eed26cff980b
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