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comparison libtomcrypt/src/pk/ecc/ltc_ecc_map.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_map.c 18 @file ltc_ecc_map.c
21 ECC Crypto, Tom St Denis 19 ECC Crypto, Tom St Denis
22 */ 20 */
23 21
24 #ifdef LTC_MECC 22 #ifdef LTC_MECC
25 23
26 /** 24 /**
27 Map a projective jacbobian point back to affine space 25 Map a projective jacbobian point back to affine space
38 LTC_ARGCHK(P != NULL); 36 LTC_ARGCHK(P != NULL);
39 LTC_ARGCHK(modulus != NULL); 37 LTC_ARGCHK(modulus != NULL);
40 LTC_ARGCHK(mp != NULL); 38 LTC_ARGCHK(mp != NULL);
41 39
42 if ((err = mp_init_multi(&t1, &t2, NULL)) != CRYPT_OK) { 40 if ((err = mp_init_multi(&t1, &t2, NULL)) != CRYPT_OK) {
43 return CRYPT_MEM; 41 return err;
44 } 42 }
45 43
46 /* first map z back to normal */ 44 /* first map z back to normal */
47 if ((err = mp_montgomery_reduce(P->z, modulus, mp)) != CRYPT_OK) { goto done; } 45 if ((err = mp_montgomery_reduce(P->z, modulus, mp)) != CRYPT_OK) { goto done; }
48 46
49 /* get 1/z */ 47 /* get 1/z */
50 if ((err = mp_invmod(P->z, modulus, t1)) != CRYPT_OK) { goto done; } 48 if ((err = mp_invmod(P->z, modulus, t1)) != CRYPT_OK) { goto done; }
51 49
52 /* get 1/z^2 and 1/z^3 */ 50 /* get 1/z^2 and 1/z^3 */
53 if ((err = mp_sqr(t1, t2)) != CRYPT_OK) { goto done; } 51 if ((err = mp_sqr(t1, t2)) != CRYPT_OK) { goto done; }
54 if ((err = mp_mod(t2, modulus, t2)) != CRYPT_OK) { goto done; } 52 if ((err = mp_mod(t2, modulus, t2)) != CRYPT_OK) { goto done; }
55 if ((err = mp_mul(t1, t2, t1)) != CRYPT_OK) { goto done; } 53 if ((err = mp_mul(t1, t2, t1)) != CRYPT_OK) { goto done; }
56 if ((err = mp_mod(t1, modulus, t1)) != CRYPT_OK) { goto done; } 54 if ((err = mp_mod(t1, modulus, t1)) != CRYPT_OK) { goto done; }
68 return err; 66 return err;
69 } 67 }
70 68
71 #endif 69 #endif
72 70
73 /* $Source$ */ 71 /* ref: $Format:%D$ */
74 /* $Revision$ */ 72 /* git commit: $Format:%H$ */
75 /* $Date$ */ 73 /* commit time: $Format:%ai$ */
76 74