1 /* $NetBSD: bn_mp_read_signed_bin.c,v 1.1.1.2 2014/04/24 12:45:31 pettai Exp $ */
2
3 #include <tommath.h>
4 #ifdef BN_MP_READ_SIGNED_BIN_C
5 /* LibTomMath, multiple-precision integer library -- Tom St Denis
6 *
7 * LibTomMath is a library that provides multiple-precision
8 * integer arithmetic as well as number theoretic functionality.
9 *
10 * The library was designed directly after the MPI library by
11 * Michael Fromberger but has been written from scratch with
12 * additional optimizations in place.
13 *
14 * The library is free for all purposes without any express
15 * guarantee it works.
16 *
17 * Tom St Denis, tomstdenis@gmail.com, http://libtom.org
18 */
19
20 /* read signed bin, big endian, first byte is 0==positive or 1==negative */
mp_read_signed_bin(mp_int * a,const unsigned char * b,int c)21 int mp_read_signed_bin (mp_int * a, const unsigned char *b, int c)
22 {
23 int res;
24
25 /* read magnitude */
26 if ((res = mp_read_unsigned_bin (a, b + 1, c - 1)) != MP_OKAY) {
27 return res;
28 }
29
30 /* first byte is 0 for positive, non-zero for negative */
31 if (b[0] == 0) {
32 a->sign = MP_ZPOS;
33 } else {
34 a->sign = MP_NEG;
35 }
36
37 return MP_OKAY;
38 }
39 #endif
40
41 /* Source: /cvs/libtom/libtommath/bn_mp_read_signed_bin.c,v */
42 /* Revision: 1.5 */
43 /* Date: 2006/12/28 01:25:13 */
44