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comparison libtommath/bn_mp_add.c @ 1655:f52919ffd3b1

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update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79) * make key-generation compliant to FIPS 186.4 * fix includes in tommath_class.h * update fuzzcorpus instead of error-out * fixup fuzzing make-targets * update Makefile.in * apply necessary patches to ltm sources * clean-up not required ltm files * update to vanilla ltm 1.1.0 this already only contains the required files * remove set/get double
author Steffen Jaeckel <s_jaeckel@gmx.de>
date Mon, 16 Sep 2019 15:50:38 +0200
parents 8bba51a55704
children 1051e4eea25a
comparison
equal deleted inserted replaced
1654:cc0fc5131c5c 1655:f52919ffd3b1
1 #include <tommath_private.h> 1 #include "tommath_private.h"
2 #ifdef BN_MP_ADD_C 2 #ifdef BN_MP_ADD_C
3 /* LibTomMath, multiple-precision integer library -- Tom St Denis 3 /* LibTomMath, multiple-precision integer library -- Tom St Denis
4 * 4 *
5 * LibTomMath is a library that provides multiple-precision 5 * LibTomMath is a library that provides multiple-precision
6 * integer arithmetic as well as number theoretic functionality. 6 * integer arithmetic as well as number theoretic functionality.
7 * 7 *
8 * The library was designed directly after the MPI library by 8 * The library was designed directly after the MPI library by
9 * Michael Fromberger but has been written from scratch with 9 * Michael Fromberger but has been written from scratch with
10 * additional optimizations in place. 10 * additional optimizations in place.
11 * 11 *
12 * The library is free for all purposes without any express 12 * SPDX-License-Identifier: Unlicense
13 * guarantee it works.
14 *
15 * Tom St Denis, [email protected], http://libtom.org
16 */ 13 */
17 14
18 /* high level addition (handles signs) */ 15 /* high level addition (handles signs) */
19 int mp_add (mp_int * a, mp_int * b, mp_int * c) 16 int mp_add(const mp_int *a, const mp_int *b, mp_int *c)
20 { 17 {
21 int sa, sb, res; 18 int sa, sb, res;
22 19
23 /* get sign of both inputs */ 20 /* get sign of both inputs */
24 sa = a->sign; 21 sa = a->sign;
25 sb = b->sign; 22 sb = b->sign;
26 23
27 /* handle two cases, not four */ 24 /* handle two cases, not four */
28 if (sa == sb) { 25 if (sa == sb) {
29 /* both positive or both negative */ 26 /* both positive or both negative */
30 /* add their magnitudes, copy the sign */ 27 /* add their magnitudes, copy the sign */
31 c->sign = sa;
32 res = s_mp_add (a, b, c);
33 } else {
34 /* one positive, the other negative */
35 /* subtract the one with the greater magnitude from */
36 /* the one of the lesser magnitude. The result gets */
37 /* the sign of the one with the greater magnitude. */
38 if (mp_cmp_mag (a, b) == MP_LT) {
39 c->sign = sb;
40 res = s_mp_sub (b, a, c);
41 } else {
42 c->sign = sa; 28 c->sign = sa;
43 res = s_mp_sub (a, b, c); 29 res = s_mp_add(a, b, c);
44 } 30 } else {
45 } 31 /* one positive, the other negative */
46 return res; 32 /* subtract the one with the greater magnitude from */
33 /* the one of the lesser magnitude. The result gets */
34 /* the sign of the one with the greater magnitude. */
35 if (mp_cmp_mag(a, b) == MP_LT) {
36 c->sign = sb;
37 res = s_mp_sub(b, a, c);
38 } else {
39 c->sign = sa;
40 res = s_mp_sub(a, b, c);
41 }
42 }
43 return res;
47 } 44 }
48 45
49 #endif 46 #endif
50 47
51 /* ref: $Format:%D$ */ 48 /* ref: HEAD -> master, tag: v1.1.0 */
52 /* git commit: $Format:%H$ */ 49 /* git commit: 08549ad6bc8b0cede0b357a9c341c5c6473a9c55 */
53 /* commit time: $Format:%ai$ */ 50 /* commit time: 2019-01-28 20:32:32 +0100 */