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 */ 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