A super trimmed down TLS stack, GPL licensed
Dependents: MiniTLS-HTTPS-Example
MiniTLS - A super trimmed down TLS/SSL Library for embedded devices Author: Donatien Garnier Copyright (C) 2013-2014 AppNearMe Ltd
This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
Diff: math/addsub/s_fp_sub.c
- Revision:
- 0:35aa5be3b78d
diff -r 000000000000 -r 35aa5be3b78d math/addsub/s_fp_sub.c --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/math/addsub/s_fp_sub.c Fri Jun 06 10:49:02 2014 +0000 @@ -0,0 +1,40 @@ +/* TomsFastMath, a fast ISO C bignum library. + * + * This project is meant to fill in where LibTomMath + * falls short. That is speed ;-) + * + * This project is public domain and free for all purposes. + * + * Tom St Denis, tomstdenis@gmail.com + */ +#include <tfm.h> + +/* unsigned subtraction ||a|| >= ||b|| ALWAYS! */ +void s_fp_sub(fp_int *a, fp_int *b, fp_int *c) +{ + int x, oldbused, oldused; + fp_word t; + + oldused = c->used; + oldbused = b->used; + c->used = a->used; + t = 0; + for (x = 0; x < oldbused; x++) { + t = ((fp_word)a->dp[x]) - (((fp_word)b->dp[x]) + t); + c->dp[x] = (fp_digit)t; + t = (t >> DIGIT_BIT)&1; + } + for (; x < a->used; x++) { + t = ((fp_word)a->dp[x]) - t; + c->dp[x] = (fp_digit)t; + t = (t >> DIGIT_BIT); + } + for (; x < oldused; x++) { + c->dp[x] = 0; + } + fp_clamp(c); +} + +/* $Source: /cvs/libtom/tomsfastmath/src/addsub/s_fp_sub.c,v $ */ +/* $Revision: 1.1 $ */ +/* $Date: 2006/12/31 21:25:53 $ */