Mercurial > dropbear
view libtommath/bn_mp_add.c @ 1692:1051e4eea25a
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.
author | Steffen Jaeckel <s@jaeckel.eu> |
---|---|
date | Tue, 26 May 2020 17:36:47 +0200 |
parents | f52919ffd3b1 |
children |
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#include "tommath_private.h" #ifdef BN_MP_ADD_C /* LibTomMath, multiple-precision integer library -- Tom St Denis */ /* SPDX-License-Identifier: Unlicense */ /* high level addition (handles signs) */ mp_err mp_add(const mp_int *a, const mp_int *b, mp_int *c) { mp_sign sa, sb; mp_err err; /* get sign of both inputs */ sa = a->sign; sb = b->sign; /* handle two cases, not four */ if (sa == sb) { /* both positive or both negative */ /* add their magnitudes, copy the sign */ c->sign = sa; err = s_mp_add(a, b, c); } else { /* one positive, the other negative */ /* subtract the one with the greater magnitude from */ /* the one of the lesser magnitude. The result gets */ /* the sign of the one with the greater magnitude. */ if (mp_cmp_mag(a, b) == MP_LT) { c->sign = sb; err = s_mp_sub(b, a, c); } else { c->sign = sa; err = s_mp_sub(a, b, c); } } return err; } #endif