|
380
|
1 /* LibTomCrypt, modular cryptographic library -- Tom St Denis |
|
|
2 * |
|
|
3 * LibTomCrypt is a library that provides various cryptographic |
|
|
4 * algorithms in a highly modular and flexible manner. |
|
|
5 * |
|
|
6 * The library is free for all purposes without any express |
|
|
7 * guarantee it works. |
|
|
8 * |
|
|
9 * Tom St Denis, [email protected], http://libtomcrypt.com |
|
|
10 */ |
|
|
11 |
|
|
12 /* Implements ECC over Z/pZ for curve y^2 = x^3 - 3x + b |
|
|
13 * |
|
|
14 * All curves taken from NIST recommendation paper of July 1999 |
|
|
15 * Available at http://csrc.nist.gov/cryptval/dss.htm |
|
|
16 */ |
|
|
17 #include "tomcrypt.h" |
|
|
18 |
|
|
19 /** |
|
|
20 @file ecc_ansi_x963_export.c |
|
|
21 ECC Crypto, Tom St Denis |
|
|
22 */ |
|
|
23 |
|
|
24 #ifdef MECC |
|
|
25 |
|
|
26 /** ECC X9.63 (Sec. 4.3.6) uncompressed export |
|
|
27 @param key Key to export |
|
|
28 @param out [out] destination of export |
|
|
29 @param outlen [in/out] Length of destination and final output size |
|
|
30 Return CRYPT_OK on success |
|
|
31 */ |
|
|
32 int ecc_ansi_x963_export(ecc_key *key, unsigned char *out, unsigned long *outlen) |
|
|
33 { |
|
|
34 unsigned char buf[ECC_BUF_SIZE]; |
|
|
35 unsigned long numlen; |
|
|
36 |
|
|
37 LTC_ARGCHK(key != NULL); |
|
|
38 LTC_ARGCHK(out != NULL); |
|
|
39 LTC_ARGCHK(outlen != NULL); |
|
|
40 |
|
|
41 if (ltc_ecc_is_valid_idx(key->idx) == 0) { |
|
|
42 return CRYPT_INVALID_ARG; |
|
|
43 } |
|
|
44 numlen = key->dp->size; |
|
|
45 |
|
|
46 if (*outlen < (1 + 2*numlen)) { |
|
|
47 *outlen = 1 + 2*numlen; |
|
|
48 return CRYPT_BUFFER_OVERFLOW; |
|
|
49 } |
|
|
50 |
|
|
51 /* store byte 0x04 */ |
|
|
52 out[0] = 0x04; |
|
|
53 |
|
|
54 /* pad and store x */ |
|
|
55 zeromem(buf, sizeof(buf)); |
|
|
56 mp_to_unsigned_bin(key->pubkey.x, buf + (numlen - mp_unsigned_bin_size(key->pubkey.x))); |
|
|
57 XMEMCPY(out+1, buf, numlen); |
|
|
58 |
|
|
59 /* pad and store y */ |
|
|
60 zeromem(buf, sizeof(buf)); |
|
|
61 mp_to_unsigned_bin(key->pubkey.y, buf + (numlen - mp_unsigned_bin_size(key->pubkey.y))); |
|
|
62 XMEMCPY(out+1+numlen, buf, numlen); |
|
|
63 |
|
|
64 *outlen = 1 + 2*numlen; |
|
|
65 return CRYPT_OK; |
|
|
66 } |
|
|
67 |
|
|
68 #endif |
|
|
69 |
|
|
70 /* $Source: /cvs/libtom/libtomcrypt/src/pk/ecc/ecc_ansi_x963_export.c,v $ */ |
|
|
71 /* $Revision: 1.4 $ */ |
|
|
72 /* $Date: 2006/12/04 02:50:11 $ */ |
