2 Unix SMB/CIFS implementation.
3 Copyright (C) Andrew Tridgell 1992-2001
4 Copyright (C) Andrew Bartlett 2002
5 Copyright (C) Rafal Szczesniak 2002
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program; if not, write to the Free Software
19 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
22 /* the Samba secrets database stores any generated, private information
23 such as the local SID and machine trust password */
29 #define DBGC_CLASS DBGC_PASSDB
31 static struct tdb_wrap *tdb;
34 * Use a TDB to store an incrementing random seed.
36 * Initialised to the current pid, the very first time Samba starts,
37 * and incremented by one each time it is needed.
39 * @note Not called by systems with a working /dev/urandom.
41 static void get_rand_seed(int *new_seed)
45 tdb_change_int32_atomic(tdb->tdb, "INFO/random_seed", new_seed, 1);
49 /* close the secrets database */
50 void secrets_shutdown(void)
55 /* open up the secrets database */
56 BOOL secrets_init(void)
64 pstrcpy(fname, lp_private_dir());
65 pstrcat(fname,"/secrets.tdb");
67 tdb = tdb_wrap_open(NULL, fname, 0, TDB_DEFAULT, O_RDWR|O_CREAT, 0600);
70 DEBUG(0,("Failed to open %s\n", fname));
75 * Set a reseed function for the crypto random generator
77 * This avoids a problem where systems without /dev/urandom
78 * could send the same challenge to multiple clients
80 set_rand_reseed_callback(get_rand_seed);
82 /* Ensure that the reseed is done now, while we are root, etc */
83 generate_random_buffer(&dummy, sizeof(dummy));
88 /* read a entry from the secrets database - the caller must free the result
89 if size is non-null then the size of the entry is put in there
91 static void *secrets_fetch(const char *key, size_t *size)
97 kbuf.dptr = strdup(key);
98 kbuf.dsize = strlen(key);
99 dbuf = tdb_fetch(tdb->tdb, kbuf);
106 /************************************************************************
107 Routine to fetch the plaintext machine account password for a realm
108 the password is assumed to be a null terminated ascii string
109 ************************************************************************/
110 char *secrets_fetch_machine_password(const char *domain)
114 asprintf(&key, "%s/%s", SECRETS_MACHINE_PASSWORD, domain);
116 ret = (char *)secrets_fetch(key, NULL);
123 /*******************************************************************************
124 Lock the secrets tdb based on a string - this is used as a primitive form of mutex
125 between smbd instances.
126 *******************************************************************************/
128 BOOL secrets_named_mutex(const char *name, uint_t timeout, size_t *p_ref_count)
130 size_t ref_count = *p_ref_count;
137 if (ref_count == 0) {
138 ret = tdb_lock_bystring(tdb->tdb, name, timeout);
140 DEBUG(10,("secrets_named_mutex: got mutex for %s\n", name ));
144 *p_ref_count = ++ref_count;
145 DEBUG(10,("secrets_named_mutex: ref_count for mutex %s = %u\n", name, (uint_t)ref_count ));
150 /*******************************************************************************
151 Unlock a named mutex.
152 *******************************************************************************/
154 void secrets_named_mutex_release(const char *name, size_t *p_ref_count)
156 size_t ref_count = *p_ref_count;
158 SMB_ASSERT(ref_count != 0);
164 if (ref_count == 1) {
165 tdb_unlock_bystring(tdb->tdb, name);
166 DEBUG(10,("secrets_named_mutex: released mutex for %s\n", name ));
169 *p_ref_count = --ref_count;
170 DEBUG(10,("secrets_named_mutex_release: ref_count for mutex %s = %u\n", name, (uint_t)ref_count ));