2 Unix SMB/CIFS implementation.
3 Authenticate to a remote server
4 Copyright (C) Andrew Tridgell 1992-1998
5 Copyright (C) Andrew Bartlett 2001
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 3 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, see <http://www.gnu.org/licenses/>.
24 #define DBGC_CLASS DBGC_AUTH
26 extern userdom_struct current_user_info
;
28 /****************************************************************************
29 Support for server level security.
30 ****************************************************************************/
32 static struct cli_state
*server_cryptkey(TALLOC_CTX
*mem_ctx
)
34 struct cli_state
*cli
= NULL
;
35 char *desthost
= NULL
;
36 struct sockaddr_storage dest_ss
;
39 bool connected_ok
= False
;
40 struct named_mutex
*mutex
= NULL
;
43 if (!(cli
= cli_initialise()))
46 /* security = server just can't function with spnego */
47 cli
->use_spnego
= False
;
49 pserver
= talloc_strdup(mem_ctx
, lp_passwordserver());
52 while(next_token_talloc(mem_ctx
, &p
, &desthost
, LIST_SEP
)) {
54 desthost
= talloc_sub_basic(mem_ctx
,
55 current_user_info
.smb_name
,
56 current_user_info
.domain
,
63 if(!resolve_name( desthost
, &dest_ss
, 0x20, false)) {
64 DEBUG(1,("server_cryptkey: Can't resolve address for %s\n",desthost
));
68 if (ismyaddr((struct sockaddr
*)&dest_ss
)) {
69 DEBUG(1,("Password server loop - disabling password server %s\n",desthost
));
73 /* we use a mutex to prevent two connections at once - when a
74 Win2k PDC get two connections where one hasn't completed a
75 session setup yet it will send a TCP reset to the first
76 connection (tridge) */
78 mutex
= grab_named_mutex(talloc_tos(), desthost
, 10);
84 status
= cli_connect(cli
, desthost
, &dest_ss
);
85 if (NT_STATUS_IS_OK(status
)) {
86 DEBUG(3,("connected to password server %s\n",desthost
));
90 DEBUG(10,("server_cryptkey: failed to connect to server %s. Error %s\n",
91 desthost
, nt_errstr(status
) ));
96 DEBUG(0,("password server not available\n"));
101 if (!attempt_netbios_session_request(&cli
, global_myname(),
102 desthost
, &dest_ss
)) {
104 DEBUG(1,("password server fails session request\n"));
109 if (strequal(desthost
,myhostname())) {
110 exit_server_cleanly("Password server loop!");
113 DEBUG(3,("got session\n"));
115 status
= cli_negprot(cli
);
117 if (!NT_STATUS_IS_OK(status
)) {
119 DEBUG(1, ("%s rejected the negprot: %s\n",
120 desthost
, nt_errstr(status
)));
125 if (cli
->protocol
< PROTOCOL_LANMAN2
||
126 !(cli
->sec_mode
& NEGOTIATE_SECURITY_USER_LEVEL
)) {
128 DEBUG(1,("%s isn't in user level security mode\n",desthost
));
133 /* Get the first session setup done quickly, to avoid silly
134 Win2k bugs. (The next connection to the server will kill
138 if (!NT_STATUS_IS_OK(cli_session_setup(cli
, "", "", 0, "", 0,
141 DEBUG(0,("%s rejected the initial session setup (%s)\n",
142 desthost
, cli_errstr(cli
)));
149 DEBUG(3,("password server OK\n"));
154 struct server_security_state
{
155 struct cli_state
*cli
;
158 /****************************************************************************
159 Send a 'keepalive' packet down the cli pipe.
160 ****************************************************************************/
162 static bool send_server_keepalive(const struct timeval
*now
,
165 struct server_security_state
*state
= talloc_get_type_abort(
166 private_data
, struct server_security_state
);
168 if (!state
->cli
|| !state
->cli
->initialised
) {
172 if (send_keepalive(state
->cli
->fd
)) {
176 DEBUG( 2, ( "send_server_keepalive: password server keepalive "
178 cli_shutdown(state
->cli
);
183 static int destroy_server_security(struct server_security_state
*state
)
186 cli_shutdown(state
->cli
);
191 static struct server_security_state
*make_server_security_state(struct cli_state
*cli
)
193 struct server_security_state
*result
;
195 if (!(result
= talloc(NULL
, struct server_security_state
))) {
196 DEBUG(0, ("talloc failed\n"));
202 talloc_set_destructor(result
, destroy_server_security
);
204 if (lp_keepalive() != 0) {
205 struct timeval interval
;
206 interval
.tv_sec
= lp_keepalive();
207 interval
.tv_usec
= 0;
209 if (event_add_idle(smbd_event_context(), result
, interval
,
210 "server_security_keepalive",
211 send_server_keepalive
,
213 DEBUG(0, ("event_add_idle failed\n"));
222 /****************************************************************************
223 Get the challenge out of a password server.
224 ****************************************************************************/
226 static DATA_BLOB
auth_get_challenge_server(const struct auth_context
*auth_context
,
227 void **my_private_data
,
230 struct cli_state
*cli
= server_cryptkey(mem_ctx
);
233 DEBUG(3,("using password server validation\n"));
235 if ((cli
->sec_mode
& NEGOTIATE_SECURITY_CHALLENGE_RESPONSE
) == 0) {
236 /* We can't work with unencrypted password servers
237 unless 'encrypt passwords = no' */
238 DEBUG(5,("make_auth_info_server: Server is unencrypted, no challenge available..\n"));
240 /* However, it is still a perfectly fine connection
241 to pass that unencrypted password over */
243 (void *)make_server_security_state(cli
);
244 return data_blob_null
;
245 } else if (cli
->secblob
.length
< 8) {
246 /* We can't do much if we don't get a full challenge */
247 DEBUG(2,("make_auth_info_server: Didn't receive a full challenge from server\n"));
249 return data_blob_null
;
252 if (!(*my_private_data
= (void *)make_server_security_state(cli
))) {
253 return data_blob(NULL
,0);
256 /* The return must be allocated on the caller's mem_ctx, as our own will be
257 destoyed just after the call. */
258 return data_blob_talloc((TALLOC_CTX
*)auth_context
, cli
->secblob
.data
,8);
260 return data_blob_null
;
265 /****************************************************************************
266 Check for a valid username and password in security=server mode.
267 - Validate a password with the password server.
268 ****************************************************************************/
270 static NTSTATUS
check_smbserver_security(const struct auth_context
*auth_context
,
271 void *my_private_data
,
273 const struct auth_usersupplied_info
*user_info
,
274 struct auth_serversupplied_info
**server_info
)
276 struct server_security_state
*state
= talloc_get_type_abort(
277 my_private_data
, struct server_security_state
);
278 struct cli_state
*cli
;
279 static bool tested_password_server
= False
;
280 static bool bad_password_server
= False
;
281 NTSTATUS nt_status
= NT_STATUS_NOT_IMPLEMENTED
;
282 bool locally_made_cli
= False
;
284 DEBUG(10, ("Check auth for: [%s]\n", user_info
->internal_username
));
290 cli
= server_cryptkey(mem_ctx
);
291 locally_made_cli
= True
;
294 if (!cli
|| !cli
->initialised
) {
295 DEBUG(1,("password server is not connected (cli not initialised)\n"));
296 return NT_STATUS_LOGON_FAILURE
;
299 if ((cli
->sec_mode
& NEGOTIATE_SECURITY_CHALLENGE_RESPONSE
) == 0) {
300 if (user_info
->encrypted
) {
301 DEBUG(1,("password server %s is plaintext, but we are encrypted. This just can't work :-(\n", cli
->desthost
));
302 return NT_STATUS_LOGON_FAILURE
;
305 if (memcmp(cli
->secblob
.data
, auth_context
->challenge
.data
, 8) != 0) {
306 DEBUG(1,("the challenge that the password server (%s) supplied us is not the one we gave our client. This just can't work :-(\n", cli
->desthost
));
307 return NT_STATUS_LOGON_FAILURE
;
312 * Attempt a session setup with a totally incorrect password.
313 * If this succeeds with the guest bit *NOT* set then the password
314 * server is broken and is not correctly setting the guest bit. We
315 * need to detect this as some versions of NT4.x are broken. JRA.
318 /* I sure as hell hope that there aren't servers out there that take
319 * NTLMv2 and have this bug, as we don't test for that...
320 * - abartlet@samba.org
323 if ((!tested_password_server
) && (lp_paranoid_server_security())) {
324 unsigned char badpass
[24];
325 char *baduser
= NULL
;
327 memset(badpass
, 0x1f, sizeof(badpass
));
329 if((user_info
->nt_resp
.length
== sizeof(badpass
)) &&
330 !memcmp(badpass
, user_info
->nt_resp
.data
, sizeof(badpass
))) {
332 * Very unlikely, our random bad password is the same as the users
335 memset(badpass
, badpass
[0]+1, sizeof(badpass
));
338 baduser
= talloc_asprintf(mem_ctx
,
343 return NT_STATUS_NO_MEMORY
;
346 if (NT_STATUS_IS_OK(cli_session_setup(cli
, baduser
,
351 user_info
->domain
))) {
354 * We connected to the password server so we
355 * can say we've tested it.
357 tested_password_server
= True
;
359 if ((SVAL(cli
->inbuf
,smb_vwv2
) & 1) == 0) {
360 DEBUG(0,("server_validate: password server %s allows users as non-guest \
361 with a bad password.\n", cli
->desthost
));
362 DEBUG(0,("server_validate: This is broken (and insecure) behaviour. Please do not \
363 use this machine as the password server.\n"));
367 * Password server has the bug.
369 bad_password_server
= True
;
370 return NT_STATUS_LOGON_FAILURE
;
377 * We have already tested the password server.
378 * Fail immediately if it has the bug.
381 if(bad_password_server
) {
382 DEBUG(0,("server_validate: [1] password server %s allows users as non-guest \
383 with a bad password.\n", cli
->desthost
));
384 DEBUG(0,("server_validate: [1] This is broken (and insecure) behaviour. Please do not \
385 use this machine as the password server.\n"));
386 return NT_STATUS_LOGON_FAILURE
;
391 * Now we know the password server will correctly set the guest bit, or is
392 * not guest enabled, we can try with the real password.
395 if (!user_info
->encrypted
) {
396 /* Plaintext available */
397 nt_status
= cli_session_setup(
398 cli
, user_info
->smb_name
,
399 (char *)user_info
->plaintext_password
.data
,
400 user_info
->plaintext_password
.length
,
401 NULL
, 0, user_info
->domain
);
404 nt_status
= cli_session_setup(
405 cli
, user_info
->smb_name
,
406 (char *)user_info
->lm_resp
.data
,
407 user_info
->lm_resp
.length
,
408 (char *)user_info
->nt_resp
.data
,
409 user_info
->nt_resp
.length
,
413 if (!NT_STATUS_IS_OK(nt_status
)) {
414 DEBUG(1,("password server %s rejected the password: %s\n",
415 cli
->desthost
, nt_errstr(nt_status
)));
418 /* if logged in as guest then reject */
419 if ((SVAL(cli
->inbuf
,smb_vwv2
) & 1) != 0) {
420 DEBUG(1,("password server %s gave us guest only\n", cli
->desthost
));
421 nt_status
= NT_STATUS_LOGON_FAILURE
;
426 if (NT_STATUS_IS_OK(nt_status
)) {
427 fstring real_username
;
430 if ( (pass
= smb_getpwnam( NULL
, user_info
->internal_username
,
431 real_username
, True
)) != NULL
)
433 /* if a real user check pam account restrictions */
434 /* only really perfomed if "obey pam restriction" is true */
435 nt_status
= smb_pam_accountcheck(pass
->pw_name
);
436 if ( !NT_STATUS_IS_OK(nt_status
)) {
437 DEBUG(1, ("PAM account restriction prevents user login\n"));
440 nt_status
= make_server_info_pw(server_info
, pass
->pw_name
, pass
);
446 nt_status
= NT_STATUS_NO_SUCH_USER
;
450 if (locally_made_cli
) {
457 static NTSTATUS
auth_init_smbserver(struct auth_context
*auth_context
, const char* param
, auth_methods
**auth_method
)
459 struct auth_methods
*result
;
461 result
= TALLOC_ZERO_P(auth_context
, struct auth_methods
);
462 if (result
== NULL
) {
463 return NT_STATUS_NO_MEMORY
;
465 result
->name
= "smbserver";
466 result
->auth
= check_smbserver_security
;
467 result
->get_chal
= auth_get_challenge_server
;
469 *auth_method
= result
;
473 NTSTATUS
auth_server_init(void)
475 return smb_register_auth(AUTH_INTERFACE_VERSION
, "smbserver", auth_init_smbserver
);