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 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, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * 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, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
20 /** @file lib/authhash.c @brief The authorization hash */
31 /** @brief Structure of algorithm lookup table */
37 /** @brief Algorithm lookup table
39 * We don't use gcry_md_map_name() since that would import gcrypt's API into
40 * the disorder protocol.
42 static const struct algorithm algorithms
[] = {
43 { "SHA1", GCRY_MD_SHA1
},
44 { "sha1", GCRY_MD_SHA1
},
45 { "SHA256", GCRY_MD_SHA256
},
46 { "sha256", GCRY_MD_SHA256
},
47 { "SHA384", GCRY_MD_SHA384
},
48 { "sha384", GCRY_MD_SHA384
},
49 { "SHA512", GCRY_MD_SHA512
},
50 { "sha512", GCRY_MD_SHA512
},
53 /** @brief Number of supported algorithms */
54 #define NALGORITHMS (sizeof algorithms / sizeof *algorithms)
56 /** @brief Perform the authorization hash function
57 * @param challenge Pointer to challange
58 * @param nchallenge Size of challenge
59 * @param password Password
60 * @param algo Algorithm to use
62 * Computes H(challenge|password) and returns it as a newly allocated hex
63 * string, or returns NULL on error.
65 const char *authhash(const void *challenge
, size_t nchallenge
,
66 const char *password
, const char *algo
) {
72 assert(challenge
!= 0);
73 assert(password
!= 0);
75 for(n
= 0; n
< NALGORITHMS
; ++n
)
76 if(!strcmp(algo
, algorithms
[n
].name
))
80 id
= algorithms
[n
].id
;
85 if((e
= gcry_md_open(&h
, id
, 0))) {
86 error(0, "gcry_md_open: %s", gcry_strerror(e
));
91 h
= gcry_md_open(id
, 0);
93 gcry_md_write(h
, password
, strlen(password
));
94 gcry_md_write(h
, challenge
, nchallenge
);
95 res
= hex(gcry_md_read(h
, id
), gcry_md_get_algo_dlen(id
));
100 /** @brief Return non-zero if @p algo is a valid algorithm */
101 int valid_authhash(const char *algo
) {
104 for(n
= 0; n
< NALGORITHMS
; ++n
)
105 if(!strcmp(algo
, algorithms
[n
].name
))