| #include <tommath.h> |
| #ifdef BN_MP_NEG_C |
| /* LibTomMath, multiple-precision integer library -- Tom St Denis |
| * |
| * LibTomMath is a library that provides multiple-precision |
| * integer arithmetic as well as number theoretic functionality. |
| * |
| * The library was 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://math.libtomcrypt.org |
| */ |
| |
| /* b = -a */ |
| int mp_neg (mp_int * a, mp_int * b) |
| { |
| int res; |
| if (a != b) { |
| if ((res = mp_copy (a, b)) != MP_OKAY) { |
| return res; |
| } |
| } |
| |
| if (mp_iszero(b) != MP_YES) { |
| b->sign = (a->sign == MP_ZPOS) ? MP_NEG : MP_ZPOS; |
| } else { |
| b->sign = MP_ZPOS; |
| } |
| |
| return MP_OKAY; |
| } |
| #endif |
