/*
* This file is part of DisOrder
- * Copyright (C) 2004, 2006 Richard Kettlewell
+ * Copyright (C) 2004, 2006, 2007 Richard Kettlewell
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
#include "log.h"
#include "authhash.h"
-#ifndef AUTHHASH
-/** @brief Which hash function to use */
-# define AUTHHASH GCRY_MD_SHA1
-#endif
+/** @brief Structure of algorithm lookup table */
+struct algorithm {
+ const char *name;
+ int id;
+};
+
+/** @brief Algorithm lookup table
+ *
+ * We don't use gcry_md_map_name() since that would import gcrypt's API into
+ * the disorder protocol.
+ */
+static const struct algorithm algorithms[] = {
+ { "SHA1", GCRY_MD_SHA1 },
+ { "sha1", GCRY_MD_SHA1 },
+ { "SHA256", GCRY_MD_SHA256 },
+ { "sha256", GCRY_MD_SHA256 },
+ { "SHA384", GCRY_MD_SHA384 },
+ { "sha384", GCRY_MD_SHA384 },
+ { "SHA512", GCRY_MD_SHA512 },
+ { "sha512", GCRY_MD_SHA512 },
+};
+
+/** @brief Number of supported algorithms */
+#define NALGORITHMS (sizeof algorithms / sizeof *algorithms)
/** @brief Perform the authorization hash function
* @param challenge Pointer to challange
* @param nchallenge Size of challenge
* @param password Password
+ * @param algo Algorithm to use
*
* Computes H(challenge|password) and returns it as a newly allocated hex
- * string. Currently the hash function is SHA-1, but this may be changed in
- * future versions; see @ref AUTHHASH.
+ * string, or returns NULL on error.
*/
const char *authhash(const void *challenge, size_t nchallenge,
- const char *password) {
+ const char *password, const char *algo) {
gcrypt_hash_handle h;
const char *res;
+ size_t n;
+ int id;
assert(challenge != 0);
assert(password != 0);
+ assert(algo != 0);
+ for(n = 0; n < NALGORITHMS; ++n)
+ if(!strcmp(algo, algorithms[n].name))
+ break;
+ if(n >= NALGORITHMS)
+ return NULL;
+ id = algorithms[n].id;
#if HAVE_GCRY_ERROR_T
{
gcry_error_t e;
- if((e = gcry_md_open(&h, AUTHHASH, 0))) {
+ if((e = gcry_md_open(&h, id, 0))) {
error(0, "gcry_md_open: %s", gcry_strerror(e));
return 0;
}
}
#else
- h = gcry_md_open(AUTHHASH, 0);
+ h = gcry_md_open(id, 0);
#endif
gcry_md_write(h, password, strlen(password));
gcry_md_write(h, challenge, nchallenge);
- res = hex(gcry_md_read(h, AUTHHASH), gcry_md_get_algo_dlen(AUTHHASH));
+ res = hex(gcry_md_read(h, id), gcry_md_get_algo_dlen(id));
gcry_md_close(h);
return res;
}
+/** @brief Return non-zero if @p algo is a valid algorithm */
+int valid_authhash(const char *algo) {
+ size_t n;
+
+ for(n = 0; n < NALGORITHMS; ++n)
+ if(!strcmp(algo, algorithms[n].name))
+ return 1;
+ return 0;
+}
+
/*
Local Variables:
c-basic-offset:2