tommath/bn_mp_read_signed_bin.c
2010-07-15 17:25:15 +02:00

29 lines
861 B
C

/* LibTomMath, multiple-precision integer library -- Tom St Denis
*
* LibTomMath is library that provides for multiple-precision
* integer arithmetic as well as number theoretic functionality.
*
* The library is designed directly after the MPI library by
* Michael Fromberger but has been written from scratch with
* additional optimizations in place.
*
* The library is free for all purposes without any express
* guarantee it works.
*
* Tom St Denis, tomstdenis@iahu.ca, http://libtommath.iahu.ca
*/
#include <tommath.h>
/* read signed bin, big endian, first byte is 0==positive or 1==negative */
int
mp_read_signed_bin (mp_int * a, unsigned char *b, int c)
{
int res;
if ((res = mp_read_unsigned_bin (a, b + 1, c - 1)) != MP_OKAY) {
return res;
}
a->sign = ((b[0] == (unsigned char) 0) ? MP_ZPOS : MP_NEG);
return MP_OKAY;
}