dropbear/libtommath/bn_mp_from_sbin.c
Steffen Jaeckel b4bd23b4d2
Update LibTomMath to 1.2.0 (#84)
* update C files

* update other files

* update headers

* update makefiles

* remove mp_set/get_double()

* use ltm 1.2.0 API

* update ltm_desc

* use bundled tommath if system-tommath is too old

* XMALLOC etc. were changed to MP_MALLOC etc.
2020-05-26 23:36:47 +08:00

26 lines
635 B
C

#include "tommath_private.h"
#ifdef BN_MP_FROM_SBIN_C
/* LibTomMath, multiple-precision integer library -- Tom St Denis */
/* SPDX-License-Identifier: Unlicense */
/* read signed bin, big endian, first byte is 0==positive or 1==negative */
mp_err mp_from_sbin(mp_int *a, const unsigned char *buf, size_t size)
{
mp_err err;
/* read magnitude */
if ((err = mp_from_ubin(a, buf + 1, size - 1u)) != MP_OKAY) {
return err;
}
/* first byte is 0 for positive, non-zero for negative */
if (buf[0] == (unsigned char)0) {
a->sign = MP_ZPOS;
} else {
a->sign = MP_NEG;
}
return MP_OKAY;
}
#endif