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comparison libtommath/bn_mp_submod.c @ 1739:13d834efc376 fuzz

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merge from main
author Matt Johnston <matt@ucc.asn.au>
date Thu, 15 Oct 2020 19:55:15 +0800
parents 1051e4eea25a
children
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1562:768ebf737aa0 1739:13d834efc376
1 #include <tommath_private.h> 1 #include "tommath_private.h"
2 #ifdef BN_MP_SUBMOD_C 2 #ifdef BN_MP_SUBMOD_C
3 /* LibTomMath, multiple-precision integer library -- Tom St Denis 3 /* LibTomMath, multiple-precision integer library -- Tom St Denis */
4 * 4 /* SPDX-License-Identifier: Unlicense */
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, [email protected], http://libtom.org
16 */
17 5
18 /* d = a - b (mod c) */ 6 /* d = a - b (mod c) */
19 int 7 mp_err mp_submod(const mp_int *a, const mp_int *b, const mp_int *c, mp_int *d)
20 mp_submod (mp_int * a, mp_int * b, mp_int * c, mp_int * d)
21 { 8 {
22 int res; 9 mp_err err;
23 mp_int t; 10 mp_int t;
24 11
12 if ((err = mp_init(&t)) != MP_OKAY) {
13 return err;
14 }
25 15
26 if ((res = mp_init (&t)) != MP_OKAY) { 16 if ((err = mp_sub(a, b, &t)) != MP_OKAY) {
27 return res; 17 goto LBL_ERR;
28 } 18 }
19 err = mp_mod(&t, c, d);
29 20
30 if ((res = mp_sub (a, b, &t)) != MP_OKAY) { 21 LBL_ERR:
31 mp_clear (&t); 22 mp_clear(&t);
32 return res; 23 return err;
33 }
34 res = mp_mod (&t, c, d);
35 mp_clear (&t);
36 return res;
37 } 24 }
38 #endif 25 #endif
39
40 /* ref: $Format:%D$ */
41 /* git commit: $Format:%H$ */
42 /* commit time: $Format:%ai$ */