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comparison libtommath/bn_mp_exteuclid.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_EXTEUCLID_C 2 #ifdef BN_MP_EXTEUCLID_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 /* Extended euclidean algorithm of (a, b) produces 15 /* Extended euclidean algorithm of (a, b) produces
19 a*u1 + b*u2 = u3 16 a*u1 + b*u2 = u3
20 */ 17 */
21 int mp_exteuclid(mp_int *a, mp_int *b, mp_int *U1, mp_int *U2, mp_int *U3) 18 int mp_exteuclid(const mp_int *a, const mp_int *b, mp_int *U1, mp_int *U2, mp_int *U3)
22 { 19 {
23 mp_int u1,u2,u3,v1,v2,v3,t1,t2,t3,q,tmp; 20 mp_int u1, u2, u3, v1, v2, v3, t1, t2, t3, q, tmp;
24 int err; 21 int err;
25 22
26 if ((err = mp_init_multi(&u1, &u2, &u3, &v1, &v2, &v3, &t1, &t2, &t3, &q, &tmp, NULL)) != MP_OKAY) { 23 if ((err = mp_init_multi(&u1, &u2, &u3, &v1, &v2, &v3, &t1, &t2, &t3, &q, &tmp, NULL)) != MP_OKAY) {
27 return err; 24 return err;
28 } 25 }
29 26
30 /* initialize, (u1,u2,u3) = (1,0,a) */ 27 /* initialize, (u1,u2,u3) = (1,0,a) */
31 mp_set(&u1, 1); 28 mp_set(&u1, 1uL);
32 if ((err = mp_copy(a, &u3)) != MP_OKAY) { goto LBL_ERR; } 29 if ((err = mp_copy(a, &u3)) != MP_OKAY) {
30 goto LBL_ERR;
31 }
33 32
34 /* initialize, (v1,v2,v3) = (0,1,b) */ 33 /* initialize, (v1,v2,v3) = (0,1,b) */
35 mp_set(&v2, 1); 34 mp_set(&v2, 1uL);
36 if ((err = mp_copy(b, &v3)) != MP_OKAY) { goto LBL_ERR; } 35 if ((err = mp_copy(b, &v3)) != MP_OKAY) {
36 goto LBL_ERR;
37 }
37 38
38 /* loop while v3 != 0 */ 39 /* loop while v3 != 0 */
39 while (mp_iszero(&v3) == MP_NO) { 40 while (mp_iszero(&v3) == MP_NO) {
40 /* q = u3/v3 */ 41 /* q = u3/v3 */
41 if ((err = mp_div(&u3, &v3, &q, NULL)) != MP_OKAY) { goto LBL_ERR; } 42 if ((err = mp_div(&u3, &v3, &q, NULL)) != MP_OKAY) {
43 goto LBL_ERR;
44 }
42 45
43 /* (t1,t2,t3) = (u1,u2,u3) - (v1,v2,v3)q */ 46 /* (t1,t2,t3) = (u1,u2,u3) - (v1,v2,v3)q */
44 if ((err = mp_mul(&v1, &q, &tmp)) != MP_OKAY) { goto LBL_ERR; } 47 if ((err = mp_mul(&v1, &q, &tmp)) != MP_OKAY) {
45 if ((err = mp_sub(&u1, &tmp, &t1)) != MP_OKAY) { goto LBL_ERR; } 48 goto LBL_ERR;
46 if ((err = mp_mul(&v2, &q, &tmp)) != MP_OKAY) { goto LBL_ERR; } 49 }
47 if ((err = mp_sub(&u2, &tmp, &t2)) != MP_OKAY) { goto LBL_ERR; } 50 if ((err = mp_sub(&u1, &tmp, &t1)) != MP_OKAY) {
48 if ((err = mp_mul(&v3, &q, &tmp)) != MP_OKAY) { goto LBL_ERR; } 51 goto LBL_ERR;
49 if ((err = mp_sub(&u3, &tmp, &t3)) != MP_OKAY) { goto LBL_ERR; } 52 }
53 if ((err = mp_mul(&v2, &q, &tmp)) != MP_OKAY) {
54 goto LBL_ERR;
55 }
56 if ((err = mp_sub(&u2, &tmp, &t2)) != MP_OKAY) {
57 goto LBL_ERR;
58 }
59 if ((err = mp_mul(&v3, &q, &tmp)) != MP_OKAY) {
60 goto LBL_ERR;
61 }
62 if ((err = mp_sub(&u3, &tmp, &t3)) != MP_OKAY) {
63 goto LBL_ERR;
64 }
50 65
51 /* (u1,u2,u3) = (v1,v2,v3) */ 66 /* (u1,u2,u3) = (v1,v2,v3) */
52 if ((err = mp_copy(&v1, &u1)) != MP_OKAY) { goto LBL_ERR; } 67 if ((err = mp_copy(&v1, &u1)) != MP_OKAY) {
53 if ((err = mp_copy(&v2, &u2)) != MP_OKAY) { goto LBL_ERR; } 68 goto LBL_ERR;
54 if ((err = mp_copy(&v3, &u3)) != MP_OKAY) { goto LBL_ERR; } 69 }
70 if ((err = mp_copy(&v2, &u2)) != MP_OKAY) {
71 goto LBL_ERR;
72 }
73 if ((err = mp_copy(&v3, &u3)) != MP_OKAY) {
74 goto LBL_ERR;
75 }
55 76
56 /* (v1,v2,v3) = (t1,t2,t3) */ 77 /* (v1,v2,v3) = (t1,t2,t3) */
57 if ((err = mp_copy(&t1, &v1)) != MP_OKAY) { goto LBL_ERR; } 78 if ((err = mp_copy(&t1, &v1)) != MP_OKAY) {
58 if ((err = mp_copy(&t2, &v2)) != MP_OKAY) { goto LBL_ERR; } 79 goto LBL_ERR;
59 if ((err = mp_copy(&t3, &v3)) != MP_OKAY) { goto LBL_ERR; } 80 }
81 if ((err = mp_copy(&t2, &v2)) != MP_OKAY) {
82 goto LBL_ERR;
83 }
84 if ((err = mp_copy(&t3, &v3)) != MP_OKAY) {
85 goto LBL_ERR;
86 }
60 } 87 }
61 88
62 /* make sure U3 >= 0 */ 89 /* make sure U3 >= 0 */
63 if (u3.sign == MP_NEG) { 90 if (u3.sign == MP_NEG) {
64 if ((err = mp_neg(&u1, &u1)) != MP_OKAY) { goto LBL_ERR; } 91 if ((err = mp_neg(&u1, &u1)) != MP_OKAY) {
65 if ((err = mp_neg(&u2, &u2)) != MP_OKAY) { goto LBL_ERR; } 92 goto LBL_ERR;
66 if ((err = mp_neg(&u3, &u3)) != MP_OKAY) { goto LBL_ERR; } 93 }
94 if ((err = mp_neg(&u2, &u2)) != MP_OKAY) {
95 goto LBL_ERR;
96 }
97 if ((err = mp_neg(&u3, &u3)) != MP_OKAY) {
98 goto LBL_ERR;
99 }
67 } 100 }
68 101
69 /* copy result out */ 102 /* copy result out */
70 if (U1 != NULL) { mp_exch(U1, &u1); } 103 if (U1 != NULL) {
71 if (U2 != NULL) { mp_exch(U2, &u2); } 104 mp_exch(U1, &u1);
72 if (U3 != NULL) { mp_exch(U3, &u3); } 105 }
106 if (U2 != NULL) {
107 mp_exch(U2, &u2);
108 }
109 if (U3 != NULL) {
110 mp_exch(U3, &u3);
111 }
73 112
74 err = MP_OKAY; 113 err = MP_OKAY;
75 LBL_ERR: 114 LBL_ERR:
76 mp_clear_multi(&u1, &u2, &u3, &v1, &v2, &v3, &t1, &t2, &t3, &q, &tmp, NULL); 115 mp_clear_multi(&u1, &u2, &u3, &v1, &v2, &v3, &t1, &t2, &t3, &q, &tmp, NULL);
77 return err; 116 return err;
78 } 117 }
79 #endif 118 #endif
80 119
81 /* ref: $Format:%D$ */ 120 /* ref: HEAD -> master, tag: v1.1.0 */
82 /* git commit: $Format:%H$ */ 121 /* git commit: 08549ad6bc8b0cede0b357a9c341c5c6473a9c55 */
83 /* commit time: $Format:%ai$ */ 122 /* commit time: 2019-01-28 20:32:32 +0100 */