Mercurial > dropbear
view libtommath/bn_mp_mod.c @ 1663:c795520269f9
Fallback for key gen without hard link support (#89)
Add a non-atomic fallback for key generation on platforms where link()
is not permitted (such as most stock Android installs) or on filesystems
without hard link support (such as FAT).
author | Matt Robinson <git@nerdoftheherd.com> |
---|---|
date | Sat, 14 Mar 2020 14:37:35 +0000 |
parents | f52919ffd3b1 |
children | 1051e4eea25a |
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#include "tommath_private.h" #ifdef BN_MP_MOD_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. * * SPDX-License-Identifier: Unlicense */ /* c = a mod b, 0 <= c < b if b > 0, b < c <= 0 if b < 0 */ int mp_mod(const mp_int *a, const mp_int *b, mp_int *c) { mp_int t; int res; if ((res = mp_init_size(&t, b->used)) != MP_OKAY) { return res; } if ((res = mp_div(a, b, NULL, &t)) != MP_OKAY) { mp_clear(&t); return res; } if ((mp_iszero(&t) != MP_NO) || (t.sign == b->sign)) { res = MP_OKAY; mp_exch(&t, c); } else { res = mp_add(b, &t, c); } mp_clear(&t); return res; } #endif /* ref: HEAD -> master, tag: v1.1.0 */ /* git commit: 08549ad6bc8b0cede0b357a9c341c5c6473a9c55 */ /* commit time: 2019-01-28 20:32:32 +0100 */