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comparison libtomcrypt/src/pk/ecc/ecc_ansi_x963_import.c @ 382:0cbe8f6dbf9e

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propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 2af22fb4e878750b88f80f90d439b316d229796f) to branch 'au.asn.ucc.matt.dropbear' (head 02c413252c90e9de8e03d91e9939dde3029f5c0a)
author Matt Johnston <matt@ucc.asn.au>
date Thu, 11 Jan 2007 02:41:05 +0000
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children f849a5ca2efc
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379:b66a00272a90 382:0cbe8f6dbf9e
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_import.c
21 ECC Crypto, Tom St Denis
22 */
23
24 #ifdef MECC
25
26 /** Import an ANSI X9.63 format public key
27 @param in The input data to read
28 @param inlen The length of the input data
29 @param key [out] destination to store imported key \
30 */
31 int ecc_ansi_x963_import(const unsigned char *in, unsigned long inlen, ecc_key *key)
32 {
33 return ecc_ansi_x963_import_ex(in, inlen, key, NULL);
34 }
35
36 int ecc_ansi_x963_import_ex(const unsigned char *in, unsigned long inlen, ecc_key *key, ltc_ecc_set_type *dp)
37 {
38 int x, err;
39
40 LTC_ARGCHK(in != NULL);
41 LTC_ARGCHK(key != NULL);
42
43 /* must be odd */
44 if ((inlen & 1) == 0) {
45 return CRYPT_INVALID_ARG;
46 }
47
48 /* init key */
49 if (mp_init_multi(&key->pubkey.x, &key->pubkey.y, &key->pubkey.z, &key->k, NULL) != CRYPT_OK) {
50 return CRYPT_MEM;
51 }
52
53 /* check for 4, 6 or 7 */
54 if (in[0] != 4 && in[0] != 6 && in[0] != 7) {
55 err = CRYPT_INVALID_PACKET;
56 goto error;
57 }
58
59 /* read data */
60 if ((err = mp_read_unsigned_bin(key->pubkey.x, (unsigned char *)in+1, (inlen-1)>>1)) != CRYPT_OK) {
61 goto error;
62 }
63
64 if ((err = mp_read_unsigned_bin(key->pubkey.y, (unsigned char *)in+1+((inlen-1)>>1), (inlen-1)>>1)) != CRYPT_OK) {
65 goto error;
66 }
67 if ((err = mp_set(key->pubkey.z, 1)) != CRYPT_OK) { goto error; }
68
69 if (dp == NULL) {
70 /* determine the idx */
71 for (x = 0; ltc_ecc_sets[x].size != 0; x++) {
72 if ((unsigned)ltc_ecc_sets[x].size >= ((inlen-1)>>1)) {
73 break;
74 }
75 }
76 if (ltc_ecc_sets[x].size == 0) {
77 err = CRYPT_INVALID_PACKET;
78 goto error;
79 }
80 /* set the idx */
81 key->idx = x;
82 key->dp = &ltc_ecc_sets[x];
83 } else {
84 if (((inlen-1)>>1) != (unsigned long) dp->size) {
85 err = CRYPT_INVALID_PACKET;
86 goto error;
87 }
88 key->idx = -1;
89 key->dp = dp;
90 }
91 key->type = PK_PUBLIC;
92
93 /* we're done */
94 return CRYPT_OK;
95 error:
96 mp_clear_multi(key->pubkey.x, key->pubkey.y, key->pubkey.z, key->k, NULL);
97 return err;
98 }
99
100 #endif
101
102 /* $Source: /cvs/libtom/libtomcrypt/src/pk/ecc/ecc_ansi_x963_import.c,v $ */
103 /* $Revision: 1.9 $ */
104 /* $Date: 2006/12/04 22:17:46 $ */