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comparison libtomcrypt/src/pk/ecc/ecc_ansi_x963_export.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 ecc_ansi_x963_export.c 18 @file ecc_ansi_x963_export.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 /** ECC X9.63 (Sec. 4.3.6) uncompressed export 24 /** ECC X9.63 (Sec. 4.3.6) uncompressed export
27 @param key Key to export 25 @param key Key to export
30 Return CRYPT_OK on success 28 Return CRYPT_OK on success
31 */ 29 */
32 int ecc_ansi_x963_export(ecc_key *key, unsigned char *out, unsigned long *outlen) 30 int ecc_ansi_x963_export(ecc_key *key, unsigned char *out, unsigned long *outlen)
33 { 31 {
34 unsigned char buf[ECC_BUF_SIZE]; 32 unsigned char buf[ECC_BUF_SIZE];
35 unsigned long numlen; 33 unsigned long numlen, xlen, ylen;
36 34
37 LTC_ARGCHK(key != NULL); 35 LTC_ARGCHK(key != NULL);
38 LTC_ARGCHK(out != NULL);
39 LTC_ARGCHK(outlen != NULL); 36 LTC_ARGCHK(outlen != NULL);
40 37
41 if (ltc_ecc_is_valid_idx(key->idx) == 0) { 38 if (ltc_ecc_is_valid_idx(key->idx) == 0) {
42 return CRYPT_INVALID_ARG; 39 return CRYPT_INVALID_ARG;
43 } 40 }
44 numlen = key->dp->size; 41 numlen = key->dp->size;
42 xlen = mp_unsigned_bin_size(key->pubkey.x);
43 ylen = mp_unsigned_bin_size(key->pubkey.y);
44
45 if (xlen > numlen || ylen > numlen || sizeof(buf) < numlen) {
46 return CRYPT_BUFFER_OVERFLOW;
47 }
45 48
46 if (*outlen < (1 + 2*numlen)) { 49 if (*outlen < (1 + 2*numlen)) {
47 *outlen = 1 + 2*numlen; 50 *outlen = 1 + 2*numlen;
48 return CRYPT_BUFFER_OVERFLOW; 51 return CRYPT_BUFFER_OVERFLOW;
49 } 52 }
50 53
54 LTC_ARGCHK(out != NULL);
55
51 /* store byte 0x04 */ 56 /* store byte 0x04 */
52 out[0] = 0x04; 57 out[0] = 0x04;
53 58
54 /* pad and store x */ 59 /* pad and store x */
55 zeromem(buf, sizeof(buf)); 60 zeromem(buf, sizeof(buf));
56 mp_to_unsigned_bin(key->pubkey.x, buf + (numlen - mp_unsigned_bin_size(key->pubkey.x))); 61 mp_to_unsigned_bin(key->pubkey.x, buf + (numlen - xlen));
57 XMEMCPY(out+1, buf, numlen); 62 XMEMCPY(out+1, buf, numlen);
58 63
59 /* pad and store y */ 64 /* pad and store y */
60 zeromem(buf, sizeof(buf)); 65 zeromem(buf, sizeof(buf));
61 mp_to_unsigned_bin(key->pubkey.y, buf + (numlen - mp_unsigned_bin_size(key->pubkey.y))); 66 mp_to_unsigned_bin(key->pubkey.y, buf + (numlen - ylen));
62 XMEMCPY(out+1+numlen, buf, numlen); 67 XMEMCPY(out+1+numlen, buf, numlen);
63 68
64 *outlen = 1 + 2*numlen; 69 *outlen = 1 + 2*numlen;
65 return CRYPT_OK; 70 return CRYPT_OK;
66 } 71 }
67 72
68 #endif 73 #endif
69 74
70 /* $Source$ */ 75 /* ref: $Format:%D$ */
71 /* $Revision$ */ 76 /* git commit: $Format:%H$ */
72 /* $Date$ */ 77 /* commit time: $Format:%ai$ */