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comparison libtommath/bn_mp_invmod.c @ 1692:1051e4eea25a

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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
comparison
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1691:2d3745d58843 1692:1051e4eea25a
1 #include "tommath_private.h" 1 #include "tommath_private.h"
2 #ifdef BN_MP_INVMOD_C 2 #ifdef BN_MP_INVMOD_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 * SPDX-License-Identifier: Unlicense
13 */
14 5
15 /* hac 14.61, pp608 */ 6 /* hac 14.61, pp608 */
16 int mp_invmod(const mp_int *a, const mp_int *b, mp_int *c) 7 mp_err mp_invmod(const mp_int *a, const mp_int *b, mp_int *c)
17 { 8 {
18 /* b cannot be negative and has to be >1 */ 9 /* b cannot be negative and has to be >1 */
19 if ((b->sign == MP_NEG) || (mp_cmp_d(b, 1uL) != MP_GT)) { 10 if ((b->sign == MP_NEG) || (mp_cmp_d(b, 1uL) != MP_GT)) {
20 return MP_VAL; 11 return MP_VAL;
21 } 12 }
22 13
23 #ifdef BN_FAST_MP_INVMOD_C
24 /* if the modulus is odd we can use a faster routine instead */ 14 /* if the modulus is odd we can use a faster routine instead */
25 if ((mp_isodd(b) == MP_YES)) { 15 if (MP_HAS(S_MP_INVMOD_FAST) && MP_IS_ODD(b)) {
26 return fast_mp_invmod(a, b, c); 16 return s_mp_invmod_fast(a, b, c);
27 } 17 }
28 #endif
29 18
30 #ifdef BN_MP_INVMOD_SLOW_C 19 return MP_HAS(S_MP_INVMOD_SLOW)
31 return mp_invmod_slow(a, b, c); 20 ? s_mp_invmod_slow(a, b, c)
32 #else 21 : MP_VAL;
33 return MP_VAL;
34 #endif
35 } 22 }
36 #endif 23 #endif
37
38 /* ref: HEAD -> master, tag: v1.1.0 */
39 /* git commit: 08549ad6bc8b0cede0b357a9c341c5c6473a9c55 */
40 /* commit time: 2019-01-28 20:32:32 +0100 */