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comparison libtomcrypt/src/pk/ecc/ltc_ecc_projective_dbl_point.c @ 1471:6dba84798cd5

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Update to libtomcrypt 1.18.1, merged with Dropbear changes
author Matt Johnston <matt@ucc.asn.au>
date Fri, 09 Feb 2018 21:44:05 +0800
parents f849a5ca2efc
children
comparison
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1470:8bba51a55704 1471:6dba84798cd5
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_dbl_point.c 18 @file ltc_ecc_projective_dbl_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 Double an ECC point 25 Double an ECC point
28 @param P The point to double 26 @param P The point to double
29 @param R [out] The destination of the double 27 @param R [out] The destination of the double
60 /* Z = 2Z */ 58 /* Z = 2Z */
61 if ((err = mp_add(R->z, R->z, R->z)) != CRYPT_OK) { goto done; } 59 if ((err = mp_add(R->z, R->z, R->z)) != CRYPT_OK) { goto done; }
62 if (mp_cmp(R->z, modulus) != LTC_MP_LT) { 60 if (mp_cmp(R->z, modulus) != LTC_MP_LT) {
63 if ((err = mp_sub(R->z, modulus, R->z)) != CRYPT_OK) { goto done; } 61 if ((err = mp_sub(R->z, modulus, R->z)) != CRYPT_OK) { goto done; }
64 } 62 }
65 63
66 /* T2 = X - T1 */ 64 /* T2 = X - T1 */
67 if ((err = mp_sub(R->x, t1, t2)) != CRYPT_OK) { goto done; } 65 if ((err = mp_sub(R->x, t1, t2)) != CRYPT_OK) { goto done; }
68 if (mp_cmp_d(t2, 0) == LTC_MP_LT) { 66 if (mp_cmp_d(t2, 0) == LTC_MP_LT) {
69 if ((err = mp_add(t2, modulus, t2)) != CRYPT_OK) { goto done; } 67 if ((err = mp_add(t2, modulus, t2)) != CRYPT_OK) { goto done; }
70 } 68 }
119 if ((err = mp_sub(R->x, R->y, R->x)) != CRYPT_OK) { goto done; } 117 if ((err = mp_sub(R->x, R->y, R->x)) != CRYPT_OK) { goto done; }
120 if (mp_cmp_d(R->x, 0) == LTC_MP_LT) { 118 if (mp_cmp_d(R->x, 0) == LTC_MP_LT) {
121 if ((err = mp_add(R->x, modulus, R->x)) != CRYPT_OK) { goto done; } 119 if ((err = mp_add(R->x, modulus, R->x)) != CRYPT_OK) { goto done; }
122 } 120 }
123 121
124 /* Y = Y - X */ 122 /* Y = Y - X */
125 if ((err = mp_sub(R->y, R->x, R->y)) != CRYPT_OK) { goto done; } 123 if ((err = mp_sub(R->y, R->x, R->y)) != CRYPT_OK) { goto done; }
126 if (mp_cmp_d(R->y, 0) == LTC_MP_LT) { 124 if (mp_cmp_d(R->y, 0) == LTC_MP_LT) {
127 if ((err = mp_add(R->y, modulus, R->y)) != CRYPT_OK) { goto done; } 125 if ((err = mp_add(R->y, modulus, R->y)) != CRYPT_OK) { goto done; }
128 } 126 }
129 /* Y = Y * T1 */ 127 /* Y = Y * T1 */
132 /* Y = Y - T2 */ 130 /* Y = Y - T2 */
133 if ((err = mp_sub(R->y, t2, R->y)) != CRYPT_OK) { goto done; } 131 if ((err = mp_sub(R->y, t2, R->y)) != CRYPT_OK) { goto done; }
134 if (mp_cmp_d(R->y, 0) == LTC_MP_LT) { 132 if (mp_cmp_d(R->y, 0) == LTC_MP_LT) {
135 if ((err = mp_add(R->y, modulus, R->y)) != CRYPT_OK) { goto done; } 133 if ((err = mp_add(R->y, modulus, R->y)) != CRYPT_OK) { goto done; }
136 } 134 }
137 135
138 err = CRYPT_OK; 136 err = CRYPT_OK;
139 done: 137 done:
140 mp_clear_multi(t1, t2, NULL); 138 mp_clear_multi(t1, t2, NULL);
141 return err; 139 return err;
142 } 140 }
143 #endif 141 #endif
144 /* $Source$ */ 142 /* ref: $Format:%D$ */
145 /* $Revision$ */ 143 /* git commit: $Format:%H$ */
146 /* $Date$ */ 144 /* commit time: $Format:%ai$ */
147 145