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comparison libtommath/bn_mp_mod.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
comparison
equal deleted inserted replaced
1562:768ebf737aa0 1739:13d834efc376
1 #include <tommath_private.h> 1 #include "tommath_private.h"
2 #ifdef BN_MP_MOD_C 2 #ifdef BN_MP_MOD_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 /* c = a mod b, 0 <= c < b if b > 0, b < c <= 0 if b < 0 */ 6 /* c = a mod b, 0 <= c < b if b > 0, b < c <= 0 if b < 0 */
19 int 7 mp_err mp_mod(const mp_int *a, const mp_int *b, mp_int *c)
20 mp_mod (mp_int * a, mp_int * b, mp_int * c)
21 { 8 {
22 mp_int t; 9 mp_int t;
23 int res; 10 mp_err err;
24 11
25 if ((res = mp_init_size (&t, b->used)) != MP_OKAY) { 12 if ((err = mp_init_size(&t, b->used)) != MP_OKAY) {
26 return res; 13 return err;
27 } 14 }
28 15
29 if ((res = mp_div (a, b, NULL, &t)) != MP_OKAY) { 16 if ((err = mp_div(a, b, NULL, &t)) != MP_OKAY) {
30 mp_clear (&t); 17 goto LBL_ERR;
31 return res; 18 }
32 }
33 19
34 if ((mp_iszero(&t) != MP_NO) || (t.sign == b->sign)) { 20 if (MP_IS_ZERO(&t) || (t.sign == b->sign)) {
35 res = MP_OKAY; 21 err = MP_OKAY;
36 mp_exch (&t, c); 22 mp_exch(&t, c);
37 } else { 23 } else {
38 res = mp_add (b, &t, c); 24 err = mp_add(b, &t, c);
39 } 25 }
40 26
41 mp_clear (&t); 27 LBL_ERR:
42 return res; 28 mp_clear(&t);
29 return err;
43 } 30 }
44 #endif 31 #endif
45
46 /* ref: $Format:%D$ */
47 /* git commit: $Format:%H$ */
48 /* commit time: $Format:%ai$ */