Line data Source code
1 : #include "tommath_private.h"
2 : #ifdef BN_MP_FROM_SBIN_C
3 : /* LibTomMath, multiple-precision integer library -- Tom St Denis */
4 : /* SPDX-License-Identifier: Unlicense */
5 :
6 : /* read signed bin, big endian, first byte is 0==positive or 1==negative */
7 0 : mp_err mp_from_sbin(mp_int *a, const unsigned char *buf, size_t size)
8 : {
9 : mp_err err;
10 :
11 : /* read magnitude */
12 0 : if ((err = mp_from_ubin(a, buf + 1, size - 1u)) != MP_OKAY) {
13 0 : return err;
14 : }
15 :
16 : /* first byte is 0 for positive, non-zero for negative */
17 0 : if (buf[0] == (unsigned char)0) {
18 0 : a->sign = MP_ZPOS;
19 : } else {
20 0 : a->sign = MP_NEG;
21 : }
22 :
23 0 : return MP_OKAY;
24 : }
25 : #endif
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