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comparison libtomcrypt/src/pk/ecc/ltc_ecc_projective_add_point.c @ 1511:5916af64acd4 fuzz

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merge from main
author Matt Johnston <matt@ucc.asn.au>
date Sat, 17 Feb 2018 19:29:51 +0800
parents 6dba84798cd5
children
comparison
equal deleted inserted replaced
1457:32f990cc96b1 1511:5916af64acd4
3 * LibTomCrypt is a library that provides various cryptographic 3 * LibTomCrypt is a library that provides various cryptographic
4 * algorithms in a highly modular and flexible manner. 4 * algorithms in a highly modular and flexible manner.
5 * 5 *
6 * The library is free for all purposes without any express 6 * The library is free for all purposes without any express
7 * guarantee it works. 7 * guarantee it works.
8 *
9 * Tom St Denis, [email protected], http://libtom.org
10 */ 8 */
11 9
12 /* Implements ECC over Z/pZ for curve y^2 = x^3 - 3x + b 10 /* Implements ECC over Z/pZ for curve y^2 = x^3 - 3x + b
13 * 11 *
14 * All curves taken from NIST recommendation paper of July 1999 12 * All curves taken from NIST recommendation paper of July 1999
17 #include "tomcrypt.h" 15 #include "tomcrypt.h"
18 16
19 /** 17 /**
20 @file ltc_ecc_projective_add_point.c 18 @file ltc_ecc_projective_add_point.c
21 ECC Crypto, Tom St Denis 19 ECC Crypto, Tom St Denis
22 */ 20 */
23 21
24 #if defined(LTC_MECC) && (!defined(LTC_MECC_ACCEL) || defined(LTM_LTC_DESC)) 22 #if defined(LTC_MECC) && (!defined(LTC_MECC_ACCEL) || defined(LTM_DESC))
25 23
26 /** 24 /**
27 Add two ECC points 25 Add two ECC points
28 @param P The point to add 26 @param P The point to add
29 @param Q The point to add 27 @param Q The point to add
44 LTC_ARGCHK(mp != NULL); 42 LTC_ARGCHK(mp != NULL);
45 43
46 if ((err = mp_init_multi(&t1, &t2, &x, &y, &z, NULL)) != CRYPT_OK) { 44 if ((err = mp_init_multi(&t1, &t2, &x, &y, &z, NULL)) != CRYPT_OK) {
47 return err; 45 return err;
48 } 46 }
49 47
50 /* should we dbl instead? */ 48 /* should we dbl instead? */
51 if ((err = mp_sub(modulus, Q->y, t1)) != CRYPT_OK) { goto done; } 49 if ((err = mp_sub(modulus, Q->y, t1)) != CRYPT_OK) { goto done; }
52 50
53 if ( (mp_cmp(P->x, Q->x) == LTC_MP_EQ) && 51 if ( (mp_cmp(P->x, Q->x) == LTC_MP_EQ) &&
54 (Q->z != NULL && mp_cmp(P->z, Q->z) == LTC_MP_EQ) && 52 (Q->z != NULL && mp_cmp(P->z, Q->z) == LTC_MP_EQ) &&
55 (mp_cmp(P->y, Q->y) == LTC_MP_EQ || mp_cmp(P->y, t1) == LTC_MP_EQ)) { 53 (mp_cmp(P->y, Q->y) == LTC_MP_EQ || mp_cmp(P->y, t1) == LTC_MP_EQ)) {
56 mp_clear_multi(t1, t2, x, y, z, NULL); 54 mp_clear_multi(t1, t2, x, y, z, NULL);
57 return ltc_ecc_projective_dbl_point(P, R, modulus, mp); 55 return ltc_ecc_projective_dbl_point(P, R, modulus, mp);
58 } 56 }
142 if ((err = mp_mul(t2, x, t2)) != CRYPT_OK) { goto done; } 140 if ((err = mp_mul(t2, x, t2)) != CRYPT_OK) { goto done; }
143 if ((err = mp_montgomery_reduce(t2, modulus, mp)) != CRYPT_OK) { goto done; } 141 if ((err = mp_montgomery_reduce(t2, modulus, mp)) != CRYPT_OK) { goto done; }
144 /* T1 = T1 * X */ 142 /* T1 = T1 * X */
145 if ((err = mp_mul(t1, x, t1)) != CRYPT_OK) { goto done; } 143 if ((err = mp_mul(t1, x, t1)) != CRYPT_OK) { goto done; }
146 if ((err = mp_montgomery_reduce(t1, modulus, mp)) != CRYPT_OK) { goto done; } 144 if ((err = mp_montgomery_reduce(t1, modulus, mp)) != CRYPT_OK) { goto done; }
147 145
148 /* X = Y*Y */ 146 /* X = Y*Y */
149 if ((err = mp_sqr(y, x)) != CRYPT_OK) { goto done; } 147 if ((err = mp_sqr(y, x)) != CRYPT_OK) { goto done; }
150 if ((err = mp_montgomery_reduce(x, modulus, mp)) != CRYPT_OK) { goto done; } 148 if ((err = mp_montgomery_reduce(x, modulus, mp)) != CRYPT_OK) { goto done; }
151 /* X = X - T2 */ 149 /* X = X - T2 */
152 if ((err = mp_sub(x, t2, x)) != CRYPT_OK) { goto done; } 150 if ((err = mp_sub(x, t2, x)) != CRYPT_OK) { goto done; }
156 154
157 /* T2 = T2 - X */ 155 /* T2 = T2 - X */
158 if ((err = mp_sub(t2, x, t2)) != CRYPT_OK) { goto done; } 156 if ((err = mp_sub(t2, x, t2)) != CRYPT_OK) { goto done; }
159 if (mp_cmp_d(t2, 0) == LTC_MP_LT) { 157 if (mp_cmp_d(t2, 0) == LTC_MP_LT) {
160 if ((err = mp_add(t2, modulus, t2)) != CRYPT_OK) { goto done; } 158 if ((err = mp_add(t2, modulus, t2)) != CRYPT_OK) { goto done; }
161 } 159 }
162 /* T2 = T2 - X */ 160 /* T2 = T2 - X */
163 if ((err = mp_sub(t2, x, t2)) != CRYPT_OK) { goto done; } 161 if ((err = mp_sub(t2, x, t2)) != CRYPT_OK) { goto done; }
164 if (mp_cmp_d(t2, 0) == LTC_MP_LT) { 162 if (mp_cmp_d(t2, 0) == LTC_MP_LT) {
165 if ((err = mp_add(t2, modulus, t2)) != CRYPT_OK) { goto done; } 163 if ((err = mp_add(t2, modulus, t2)) != CRYPT_OK) { goto done; }
166 } 164 }
188 return err; 186 return err;
189 } 187 }
190 188
191 #endif 189 #endif
192 190
193 /* $Source$ */ 191 /* ref: $Format:%D$ */
194 /* $Revision$ */ 192 /* git commit: $Format:%H$ */
195 /* $Date$ */ 193 /* commit time: $Format:%ai$ */
196 194