2 ecdsa.c -- ECDSA key handling
3 Copyright (C) 2011 Guus Sliepen <guus@tinc-vpn.org>
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2 of the License, or
8 (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License along
16 with this program; if not, write to the Free Software Foundation, Inc.,
17 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
22 #include <openssl/pem.h>
23 #include <openssl/err.h>
31 bool ecdsa_set_base64_public_key(ecdsa_t *ecdsa, const char *p) {
32 *ecdsa = EC_KEY_new_by_curve_name(NID_secp521r1);
35 unsigned char pubkey[len / 4 * 3 + 3];
36 const unsigned char *ppubkey = pubkey;
37 len = b64decode(p, pubkey, len);
39 if(!o2i_ECPublicKey(ecdsa, &ppubkey, len)) {
40 logger(LOG_DEBUG, "o2i_ECPublicKey failed: %s", ERR_error_string(ERR_get_error(), NULL));
47 // Read PEM ECDSA keys
49 bool ecdsa_read_pem_public_key(ecdsa_t *ecdsa, FILE *fp) {
50 *ecdsa = PEM_read_EC_PUBKEY(fp, ecdsa, NULL, NULL);
55 logger(LOG_ERR, "Unable to read ECDSA public key: %s", ERR_error_string(ERR_get_error(), NULL));
59 bool ecdsa_read_pem_private_key(ecdsa_t *ecdsa, FILE *fp) {
60 *ecdsa = PEM_read_ECPrivateKey(fp, NULL, NULL, NULL);
65 logger(LOG_ERR, "Unable to read ECDSA private key: %s", ERR_error_string(ERR_get_error(), NULL));
69 size_t ecdsa_size(ecdsa_t *ecdsa) {
70 return ECDSA_size(*ecdsa);
73 // TODO: standardise output format?
75 bool ecdsa_sign(ecdsa_t *ecdsa, const void *in, size_t len, void *sig) {
76 unsigned int siglen = ECDSA_size(*ecdsa);
78 char hash[SHA512_DIGEST_LENGTH];
79 SHA512(in, len, hash);
81 memset(sig, 0, siglen);
83 if(!ECDSA_sign(0, hash, sizeof hash, sig, &siglen, *ecdsa)) {
84 logger(LOG_DEBUG, "ECDSA_sign() failed: %s", ERR_error_string(ERR_get_error(), NULL));
88 if(siglen != ECDSA_size(*ecdsa)) {
89 logger(LOG_ERR, "Signature length %d != %d", siglen, ECDSA_size(*ecdsa));
95 bool ecdsa_verify(ecdsa_t *ecdsa, const void *in, size_t len, const void *sig) {
96 unsigned int siglen = ECDSA_size(*ecdsa);
98 char hash[SHA512_DIGEST_LENGTH];
99 SHA512(in, len, hash);
101 if(!ECDSA_verify(0, hash, sizeof hash, sig, siglen, *ecdsa)) {
102 logger(LOG_DEBUG, "ECDSA_verify() failed: %s", ERR_error_string(ERR_get_error(), NULL));