1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
|
/*
Unix SMB/CIFS implementation.
Copyright (C) Andrew Tridgell 1992-2001
Copyright (C) Andrew Bartlett 2002
Copyright (C) Rafal Szczesniak 2002
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
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/* the Samba secrets database stores any generated, private information
such as the local SID and machine trust password */
#include "includes.h"
#undef DBGC_CLASS
#define DBGC_CLASS DBGC_PASSDB
static struct tdb_wrap *tdb;
/**
* Use a TDB to store an incrementing random seed.
*
* Initialised to the current pid, the very first time Samba starts,
* and incremented by one each time it is needed.
*
* @note Not called by systems with a working /dev/urandom.
*/
static void get_rand_seed(int *new_seed)
{
*new_seed = getpid();
if (tdb) {
tdb_change_int32_atomic(tdb->tdb, "INFO/random_seed", new_seed, 1);
}
}
/* close the secrets database */
void secrets_shutdown(void)
{
talloc_free(tdb);
}
/* open up the secrets database */
BOOL secrets_init(void)
{
pstring fname;
char dummy;
if (tdb)
return True;
pstrcpy(fname, lp_private_dir());
pstrcat(fname,"/secrets.tdb");
tdb = tdb_wrap_open(NULL, fname, 0, TDB_DEFAULT, O_RDWR|O_CREAT, 0600);
if (!tdb) {
DEBUG(0,("Failed to open %s\n", fname));
return False;
}
/**
* Set a reseed function for the crypto random generator
*
* This avoids a problem where systems without /dev/urandom
* could send the same challenge to multiple clients
*/
set_rand_reseed_callback(get_rand_seed);
/* Ensure that the reseed is done now, while we are root, etc */
generate_random_buffer(&dummy, sizeof(dummy));
return True;
}
/* read a entry from the secrets database - the caller must free the result
if size is non-null then the size of the entry is put in there
*/
static void *secrets_fetch(const char *key, size_t *size)
{
TDB_DATA kbuf, dbuf;
secrets_init();
if (!tdb)
return NULL;
kbuf.dptr = strdup(key);
kbuf.dsize = strlen(key);
dbuf = tdb_fetch(tdb->tdb, kbuf);
if (size)
*size = dbuf.dsize;
free(kbuf.dptr);
return dbuf.dptr;
}
/************************************************************************
Routine to fetch the plaintext machine account password for a realm
the password is assumed to be a null terminated ascii string
************************************************************************/
char *secrets_fetch_machine_password(const char *domain)
{
char *key;
char *ret;
asprintf(&key, "%s/%s", SECRETS_MACHINE_PASSWORD, domain);
strupper(key);
ret = (char *)secrets_fetch(key, NULL);
free(key);
return ret;
}
/*******************************************************************************
Lock the secrets tdb based on a string - this is used as a primitive form of mutex
between smbd instances.
*******************************************************************************/
BOOL secrets_named_mutex(const char *name, uint_t timeout, size_t *p_ref_count)
{
size_t ref_count = *p_ref_count;
int ret = 0;
secrets_init();
if (!tdb)
return False;
if (ref_count == 0) {
ret = tdb_lock_bystring(tdb->tdb, name, timeout);
if (ret == 0)
DEBUG(10,("secrets_named_mutex: got mutex for %s\n", name ));
}
if (ret == 0) {
*p_ref_count = ++ref_count;
DEBUG(10,("secrets_named_mutex: ref_count for mutex %s = %u\n", name, (uint_t)ref_count ));
}
return (ret == 0);
}
/*******************************************************************************
Unlock a named mutex.
*******************************************************************************/
void secrets_named_mutex_release(const char *name, size_t *p_ref_count)
{
size_t ref_count = *p_ref_count;
SMB_ASSERT(ref_count != 0);
secrets_init();
if (!tdb)
return;
if (ref_count == 1) {
tdb_unlock_bystring(tdb->tdb, name);
DEBUG(10,("secrets_named_mutex: released mutex for %s\n", name ));
}
*p_ref_count = --ref_count;
DEBUG(10,("secrets_named_mutex_release: ref_count for mutex %s = %u\n", name, (uint_t)ref_count ));
}
|
