2 digest.c -- Digest handling
3 Copyright (C) 2007-2022 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.
20 #include "../system.h"
23 #include "../digest.h"
24 #include "../logger.h"
31 {"none", GCRY_MD_NONE, 0},
32 {"sha1", GCRY_MD_SHA1, 64},
33 {"sha256", GCRY_MD_SHA256, 672},
34 {"sha384", GCRY_MD_SHA384, 673},
35 {"sha512", GCRY_MD_SHA512, 674},
38 static bool nametodigest(md_algo_t *algo, const char *name) {
39 for(size_t i = 0; i < sizeof(digesttable) / sizeof(*digesttable); i++) {
40 if(digesttable[i].name && !strcasecmp(name, digesttable[i].name)) {
41 *algo = digesttable[i].algo;
49 static bool nidtodigest(md_algo_t *algo, nid_t nid) {
50 for(size_t i = 0; i < sizeof(digesttable) / sizeof(*digesttable); i++) {
51 if(nid == digesttable[i].nid) {
52 *algo = digesttable[i].algo;
60 static bool digesttonid(nid_t *nid, md_algo_t algo) {
61 for(size_t i = 0; i < sizeof(digesttable) / sizeof(*digesttable); i++) {
62 if(algo == digesttable[i].algo) {
63 *nid = digesttable[i].nid;
71 static bool digest_open(digest_t *digest, md_algo_t algo, size_t maclength) {
72 if(!digesttonid(&digest->nid, algo)) {
73 logger(DEBUG_ALWAYS, LOG_DEBUG, "Digest %d has no corresponding nid!", algo);
77 unsigned int len = gcry_md_get_algo_dlen(algo);
80 digest->maclength = len;
82 digest->maclength = maclength;
91 bool digest_open_by_name(digest_t *digest, const char *name, size_t maclength) {
94 if(!nametodigest(&algo, name)) {
95 logger(DEBUG_ALWAYS, LOG_DEBUG, "Unknown digest name '%s'!", name);
99 return digest_open(digest, algo, maclength);
102 bool digest_open_by_nid(digest_t *digest, nid_t nid, size_t maclength) {
105 if(!nidtodigest(&algo, nid)) {
106 logger(DEBUG_ALWAYS, LOG_DEBUG, "Unknown digest ID %d!", nid);
110 return digest_open(digest, algo, maclength);
113 void digest_close(digest_t *digest) {
115 gcry_md_close(digest->hmac);
118 memset(digest, 0, sizeof(*digest));
121 bool digest_set_key(digest_t *digest, const void *key, size_t len) {
123 gcry_md_open(&digest->hmac, digest->algo, GCRY_MD_FLAG_HMAC);
130 return !gcry_md_setkey(digest->hmac, key, len);
133 bool digest_create(digest_t *digest, const void *indata, size_t inlen, void *outdata) {
134 unsigned int len = gcry_md_get_algo_dlen(digest->algo);
138 gcry_md_reset(digest->hmac);
139 gcry_md_write(digest->hmac, indata, inlen);
140 tmpdata = gcry_md_read(digest->hmac, digest->algo);
146 memcpy(outdata, tmpdata, digest->maclength);
149 gcry_md_hash_buffer(digest->algo, tmpdata, indata, inlen);
150 memcpy(outdata, tmpdata, digest->maclength);
156 bool digest_verify(digest_t *digest, const void *indata, size_t inlen, const void *cmpdata) {
157 size_t len = digest->maclength;
158 uint8_t outdata[len];
160 return digest_create(digest, indata, inlen, outdata) && !memcmp(cmpdata, outdata, len);
163 nid_t digest_get_nid(const digest_t *digest) {
164 if(!digest || !digest->nid) {
171 size_t digest_length(const digest_t *digest) {
176 return digest->maclength;
179 bool digest_active(const digest_t *digest) {
180 return digest && digest->algo != GCRY_MD_NONE;