1 #include <tommath.h> 2 #ifdef BN_MP_READ_SIGNED_BIN_C 3 /* LibTomMath, multiple-precision integer library -- Tom St Denis 4 * 5 * LibTomMath is a library that provides multiple-precision 6 * integer arithmetic as well as number theoretic functionality. 7 * 8 * The library was designed directly after the MPI library by 9 * Michael Fromberger but has been written from scratch with 10 * additional optimizations in place. 11 * 12 * The library is free for all purposes without any express 13 * guarantee it works. 14 * 15 * Tom St Denis, tomstdenis (at) gmail.com, http://math.libtomcrypt.com 16 */ 17 18 /* read signed bin, big endian, first byte is 0==positive or 1==negative */ 19 int mp_read_signed_bin (mp_int * a, const unsigned char *b, int c) 20 { 21 int res; 22 23 /* read magnitude */ 24 if ((res = mp_read_unsigned_bin (a, b + 1, c - 1)) != MP_OKAY) { 25 return res; 26 } 27 28 /* first byte is 0 for positive, non-zero for negative */ 29 if (b[0] == 0) { 30 a->sign = MP_ZPOS; 31 } else { 32 a->sign = MP_NEG; 33 } 34 35 return MP_OKAY; 36 } 37 #endif 38 39 /* $Source: /cvs/libtom/libtommath/bn_mp_read_signed_bin.c,v $ */ 40 /* $Revision: 1.4 $ */ 41 /* $Date: 2006/03/31 14:18:44 $ */ 42
