2 digest.c -- Digest handling
3 Copyright (C) 2007-2012 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.
27 enum gcry_md_algos algo;
30 {"none", GCRY_MD_NONE, 0},
31 {"sha1", GCRY_MD_SHA1, 64},
32 {"sha256", GCRY_MD_SHA256, 672},
33 {"sha384", GCRY_MD_SHA384, 673},
34 {"sha512", GCRY_MD_SHA512, 674},
37 static bool nametodigest(const char *name, enum gcry_md_algos *algo) {
40 for(i = 0; i < sizeof(digesttable) / sizeof(*digesttable); i++) {
41 if(digesttable[i].name && !strcasecmp(name, digesttable[i].name)) {
42 *algo = digesttable[i].algo;
50 static bool nidtodigest(int nid, enum gcry_md_algos *algo) {
51 for(int i = 0; i < sizeof(digesttable) / sizeof(*digesttable); i++) {
52 if(nid == digesttable[i].nid) {
53 *algo = digesttable[i].algo;
61 static bool digesttonid(enum gcry_md_algos algo, int *nid) {
62 for(int i = 0; i < sizeof(digesttable) / sizeof(*digesttable); i++) {
63 if(algo == digesttable[i].algo) {
64 *nid = digesttable[i].nid;
72 static bool digest_open(digest_t *digest, enum gcry_md_algos algo, size_t maclength) {
73 if(!digesttonid(algo, &digest->nid)) {
74 logger(DEBUG_ALWAYS, LOG_DEBUG, "Digest %d has no corresponding nid!", algo);
78 unsigned int len = gcry_md_get_algo_dlen(algo);
80 if(maclength > len || maclength < 0) {
81 digest->maclength = len;
83 digest->maclength = maclength;
92 bool digest_open_by_name(digest_t *digest, const char *name, size_t maclength) {
93 enum gcry_md_algos algo;
95 if(!nametodigest(name, &algo)) {
96 logger(DEBUG_ALWAYS, LOG_DEBUG, "Unknown digest name '%s'!", name);
100 return digest_open(digest, algo, maclength);
103 bool digest_open_by_nid(digest_t *digest, int nid, size_t maclength) {
104 enum gcry_md_algos algo;
106 if(!nidtodigest(nid, &algo)) {
107 logger(DEBUG_ALWAYS, LOG_DEBUG, "Unknown digest ID %d!", nid);
111 return digest_open(digest, algo, maclength);
114 bool digest_open_sha1(digest_t *digest, size_t maclength) {
115 return digest_open(digest, GCRY_MD_SHA1, maclength);
118 void digest_close(digest_t *digest) {
120 gcry_md_close(digest->hmac);
123 memset(digest, 0, sizeof(*digest));
126 bool digest_set_key(digest_t *digest, const void *key, size_t len) {
128 gcry_md_open(&digest->hmac, digest->algo, GCRY_MD_FLAG_HMAC);
135 return !gcry_md_setkey(digest->hmac, key, len);
138 bool digest_create(digest_t *digest, const void *indata, size_t inlen, void *outdata) {
139 unsigned int len = gcry_md_get_algo_dlen(digest->algo);
143 gcry_md_reset(digest->hmac);
144 gcry_md_write(digest->hmac, indata, inlen);
145 tmpdata = gcry_md_read(digest->hmac, digest->algo);
151 memcpy(outdata, tmpdata, digest->maclength);
154 gcry_md_hash_buffer(digest->algo, tmpdata, indata, inlen);
155 memcpy(outdata, tmpdata, digest->maclength);
161 bool digest_verify(digest_t *digest, const void *indata, size_t inlen, const void *cmpdata) {
162 size_t len = digest->maclength;
163 uint8_t outdata[len];
165 return digest_create(digest, indata, inlen, outdata) && !memcmp(cmpdata, outdata, len);
168 int digest_get_nid(const digest_t *digest) {
169 if(!digest || !digest->nid) {
176 size_t digest_length(const digest_t *digest) {
181 return digest->maclength;
184 bool digest_active(const digest_t *digest) {
185 return digest && digest->algo != GCRY_MD_NONE;