2 * This file is part of DisOrder
3 * Copyright (C) 2004, 2006, 2007 Richard Kettlewell
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 3 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
16 * along with this program. If not, see <http://www.gnu.org/licenses/>.
18 /** @file lib/authhash.c @brief The authorization hash */
29 /** @brief Structure of algorithm lookup table */
35 /** @brief Algorithm lookup table
37 * We don't use gcry_md_map_name() since that would import gcrypt's API into
38 * the disorder protocol.
40 static const struct algorithm algorithms[] = {
41 { "SHA1", GCRY_MD_SHA1 },
42 { "sha1", GCRY_MD_SHA1 },
43 { "SHA256", GCRY_MD_SHA256 },
44 { "sha256", GCRY_MD_SHA256 },
45 { "SHA384", GCRY_MD_SHA384 },
46 { "sha384", GCRY_MD_SHA384 },
47 { "SHA512", GCRY_MD_SHA512 },
48 { "sha512", GCRY_MD_SHA512 },
51 /** @brief Number of supported algorithms */
52 #define NALGORITHMS (sizeof algorithms / sizeof *algorithms)
54 /** @brief Perform the authorization hash function
55 * @param challenge Pointer to challange
56 * @param nchallenge Size of challenge
57 * @param password Password
58 * @param algo Algorithm to use
60 * Computes H(challenge|password) and returns it as a newly allocated hex
61 * string, or returns NULL on error.
63 const char *authhash(const void *challenge, size_t nchallenge,
64 const char *password, const char *algo) {
70 assert(challenge != 0);
71 assert(password != 0);
73 for(n = 0; n < NALGORITHMS; ++n)
74 if(!strcmp(algo, algorithms[n].name))
78 id = algorithms[n].id;
83 if((e = gcry_md_open(&h, id, 0))) {
84 error(0, "gcry_md_open: %s", gcry_strerror(e));
89 h = gcry_md_open(id, 0);
91 gcry_md_write(h, password, strlen(password));
92 gcry_md_write(h, challenge, nchallenge);
93 res = hex(gcry_md_read(h, id), gcry_md_get_algo_dlen(id));
98 /** @brief Return non-zero if @p algo is a valid algorithm */
99 int valid_authhash(const char *algo) {
102 for(n = 0; n < NALGORITHMS; ++n)
103 if(!strcmp(algo, algorithms[n].name))