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comparison libtommath/bn_mp_dr_is_modulus.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
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1562:768ebf737aa0 1739:13d834efc376
1 #include <tommath_private.h> 1 #include "tommath_private.h"
2 #ifdef BN_MP_DR_IS_MODULUS_C 2 #ifdef BN_MP_DR_IS_MODULUS_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 /* determines if a number is a valid DR modulus */ 6 /* determines if a number is a valid DR modulus */
19 int mp_dr_is_modulus(mp_int *a) 7 mp_bool mp_dr_is_modulus(const mp_int *a)
20 { 8 {
21 int ix; 9 int ix;
22 10
23 /* must be at least two digits */ 11 /* must be at least two digits */
24 if (a->used < 2) { 12 if (a->used < 2) {
25 return 0; 13 return MP_NO;
26 } 14 }
27 15
28 /* must be of the form b**k - a [a <= b] so all 16 /* must be of the form b**k - a [a <= b] so all
29 * but the first digit must be equal to -1 (mod b). 17 * but the first digit must be equal to -1 (mod b).
30 */ 18 */
31 for (ix = 1; ix < a->used; ix++) { 19 for (ix = 1; ix < a->used; ix++) {
32 if (a->dp[ix] != MP_MASK) { 20 if (a->dp[ix] != MP_MASK) {
33 return 0; 21 return MP_NO;
34 } 22 }
35 } 23 }
36 return 1; 24 return MP_YES;
37 } 25 }
38 26
39 #endif 27 #endif
40
41 /* ref: $Format:%D$ */
42 /* git commit: $Format:%H$ */
43 /* commit time: $Format:%ai$ */