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/>.
23 #include "system/passwd.h"
24 #include "smbd/smbd.h"
25 #include "libsmb/libsmb.h"
28 #define DBGC_CLASS DBGC_AUTH
30 extern userdom_struct current_user_info
;
32 /****************************************************************************
33 Support for server level security.
34 ****************************************************************************/
36 static struct cli_state
*server_cryptkey(TALLOC_CTX
*mem_ctx
)
38 struct cli_state
*cli
= NULL
;
39 char *desthost
= NULL
;
40 struct sockaddr_storage dest_ss
;
43 bool connected_ok
= False
;
44 struct named_mutex
*mutex
= NULL
;
46 /* security = server just can't function with spnego */
47 int flags
= CLI_FULL_CONNECTION_DONT_SPNEGO
;
48 uint16_t sec_mode
= 0;
50 pserver
= talloc_strdup(mem_ctx
, lp_passwordserver());
53 while(next_token_talloc(mem_ctx
, &p
, &desthost
, LIST_SEP
)) {
55 desthost
= talloc_sub_basic(mem_ctx
,
56 current_user_info
.smb_name
,
57 current_user_info
.domain
,
64 if (strequal(desthost
, myhostname())) {
65 DEBUG(1,("Password server loop - disabling "
66 "password server %s\n", desthost
));
70 if(!resolve_name( desthost
, &dest_ss
, 0x20, false)) {
71 DEBUG(1,("server_cryptkey: Can't resolve address for %s\n",desthost
));
75 if (ismyaddr((struct sockaddr
*)(void *)&dest_ss
)) {
76 DEBUG(1,("Password server loop - disabling password server %s\n",desthost
));
80 /* we use a mutex to prevent two connections at once - when a
81 Win2k PDC get two connections where one hasn't completed a
82 session setup yet it will send a TCP reset to the first
83 connection (tridge) */
85 mutex
= grab_named_mutex(talloc_tos(), desthost
, 10);
90 status
= cli_connect_nb(desthost
, &dest_ss
, 0, 0x20,
91 lp_netbios_name(), Undefined
, flags
, &cli
);
92 if (NT_STATUS_IS_OK(status
)) {
93 DEBUG(3,("connected to password server %s\n",desthost
));
97 DEBUG(10,("server_cryptkey: failed to connect to server %s. Error %s\n",
98 desthost
, nt_errstr(status
) ));
103 DEBUG(0,("password server not available\n"));
107 DEBUG(3,("got session\n"));
109 status
= cli_negprot(cli
, PROTOCOL_NT1
);
111 if (!NT_STATUS_IS_OK(status
)) {
113 DEBUG(1, ("%s rejected the negprot: %s\n",
114 desthost
, nt_errstr(status
)));
119 sec_mode
= cli_state_security_mode(cli
);
120 if (cli_state_protocol(cli
) < PROTOCOL_LANMAN2
||
121 !(sec_mode
& NEGOTIATE_SECURITY_USER_LEVEL
)) {
123 DEBUG(1,("%s isn't in user level security mode\n",desthost
));
128 /* Get the first session setup done quickly, to avoid silly
129 Win2k bugs. (The next connection to the server will kill
133 status
= cli_session_setup(cli
, "", "", 0, "", 0, "");
134 if (!NT_STATUS_IS_OK(status
)) {
136 DEBUG(0,("%s rejected the initial session setup (%s)\n",
137 desthost
, nt_errstr(status
)));
144 DEBUG(3,("password server OK\n"));
149 struct server_security_state
{
150 struct cli_state
*cli
;
153 /****************************************************************************
154 Send a 'keepalive' packet down the cli pipe.
155 ****************************************************************************/
157 static bool send_server_keepalive(const struct timeval
*now
,
160 struct server_security_state
*state
= talloc_get_type_abort(
161 private_data
, struct server_security_state
);
163 unsigned char garbage
[16];
165 if (!cli_state_is_connected(state
->cli
)) {
169 /* Ping the server to keep the connection alive using SMBecho. */
170 memset(garbage
, 0xf0, sizeof(garbage
));
171 status
= cli_echo(state
->cli
, 1, data_blob_const(garbage
, sizeof(garbage
)));
172 if (NT_STATUS_IS_OK(status
)) {
176 DEBUG(2,("send_server_keepalive: password server SMBecho failed: %s\n",
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(server_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 uint16_t sec_mode
= cli_state_security_mode(cli
);
234 const uint8_t *server_challenge
= cli_state_server_challenge(cli
);
236 DEBUG(3,("using password server validation\n"));
238 if ((sec_mode
& NEGOTIATE_SECURITY_CHALLENGE_RESPONSE
) == 0) {
239 /* We can't work with unencrypted password servers
240 unless 'encrypt passwords = no' */
241 DEBUG(5,("make_auth_info_server: Server is unencrypted, no challenge available..\n"));
243 /* However, it is still a perfectly fine connection
244 to pass that unencrypted password over */
246 (void *)make_server_security_state(cli
);
247 return data_blob_null
;
250 if (!(*my_private_data
= (void *)make_server_security_state(cli
))) {
251 return data_blob(NULL
,0);
254 /* The return must be allocated on the caller's mem_ctx, as our own will be
255 destoyed just after the call. */
256 return data_blob_talloc(discard_const_p(TALLOC_CTX
, auth_context
), server_challenge
,8);
258 return data_blob_null
;
263 /****************************************************************************
264 Check for a valid username and password in security=server mode.
265 - Validate a password with the password server.
266 ****************************************************************************/
268 static NTSTATUS
check_smbserver_security(const struct auth_context
*auth_context
,
269 void *my_private_data
,
271 const struct auth_usersupplied_info
*user_info
,
272 struct auth_serversupplied_info
**server_info
)
274 struct server_security_state
*state
= NULL
;
275 struct cli_state
*cli
= NULL
;
276 static bool tested_password_server
= False
;
277 static bool bad_password_server
= False
;
278 NTSTATUS nt_status
= NT_STATUS_NOT_IMPLEMENTED
;
279 bool locally_made_cli
= False
;
280 uint16_t sec_mode
= 0;
282 DEBUG(10, ("check_smbserver_security: Check auth for: [%s]\n",
283 user_info
->mapped
.account_name
));
285 if (my_private_data
== NULL
) {
286 DEBUG(10,("check_smbserver_security: "
287 "password server is not connected\n"));
288 return NT_STATUS_LOGON_FAILURE
;
291 state
= talloc_get_type_abort(my_private_data
, struct server_security_state
);
296 cli
= server_cryptkey(mem_ctx
);
297 locally_made_cli
= True
;
300 if (!cli_state_is_connected(cli
)) {
301 DEBUG(1,("password server is not connected (cli not initialised)\n"));
302 return NT_STATUS_LOGON_FAILURE
;
305 sec_mode
= cli_state_security_mode(cli
);
306 if ((sec_mode
& NEGOTIATE_SECURITY_CHALLENGE_RESPONSE
) == 0) {
307 if (user_info
->password_state
!= AUTH_PASSWORD_PLAIN
) {
308 DEBUG(1,("password server %s is plaintext, but we are encrypted. This just can't work :-(\n", cli_state_remote_name(cli
)));
309 return NT_STATUS_LOGON_FAILURE
;
312 const uint8_t *server_challenge
= cli_state_server_challenge(cli
);
314 if (memcmp(server_challenge
, auth_context
->challenge
.data
, 8) != 0) {
315 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_state_remote_name(cli
)));
316 return NT_STATUS_LOGON_FAILURE
;
321 * Attempt a session setup with a totally incorrect password.
322 * If this succeeds with the guest bit *NOT* set then the password
323 * server is broken and is not correctly setting the guest bit. We
324 * need to detect this as some versions of NT4.x are broken. JRA.
327 /* I sure as hell hope that there aren't servers out there that take
328 * NTLMv2 and have this bug, as we don't test for that...
329 * - abartlet@samba.org
332 if ((!tested_password_server
) && (lp_paranoid_server_security())) {
333 unsigned char badpass
[24];
334 char *baduser
= NULL
;
336 memset(badpass
, 0x1f, sizeof(badpass
));
338 if((user_info
->password
.response
.nt
.length
== sizeof(badpass
)) &&
339 !memcmp(badpass
, user_info
->password
.response
.nt
.data
, sizeof(badpass
))) {
341 * Very unlikely, our random bad password is the same as the users
344 memset(badpass
, badpass
[0]+1, sizeof(badpass
));
347 baduser
= talloc_asprintf(mem_ctx
,
352 return NT_STATUS_NO_MEMORY
;
355 if (NT_STATUS_IS_OK(cli_session_setup(cli
, baduser
,
360 user_info
->mapped
.domain_name
))) {
363 * We connected to the password server so we
364 * can say we've tested it.
366 tested_password_server
= True
;
368 if (!cli
->is_guestlogin
) {
369 DEBUG(0,("server_validate: password server %s allows users as non-guest \
370 with a bad password.\n", cli_state_remote_name(cli
)));
371 DEBUG(0,("server_validate: This is broken (and insecure) behaviour. Please do not \
372 use this machine as the password server.\n"));
376 * Password server has the bug.
378 bad_password_server
= True
;
379 return NT_STATUS_LOGON_FAILURE
;
386 * We have already tested the password server.
387 * Fail immediately if it has the bug.
390 if(bad_password_server
) {
391 DEBUG(0,("server_validate: [1] password server %s allows users as non-guest \
392 with a bad password.\n", cli_state_remote_name(cli
)));
393 DEBUG(0,("server_validate: [1] This is broken (and insecure) behaviour. Please do not \
394 use this machine as the password server.\n"));
395 return NT_STATUS_LOGON_FAILURE
;
400 * Now we know the password server will correctly set the guest bit, or is
401 * not guest enabled, we can try with the real password.
403 switch (user_info
->password_state
) {
404 case AUTH_PASSWORD_PLAIN
:
405 /* Plaintext available */
406 nt_status
= cli_session_setup(
407 cli
, user_info
->client
.account_name
,
408 user_info
->password
.plaintext
,
409 strlen(user_info
->password
.plaintext
),
410 NULL
, 0, user_info
->mapped
.domain_name
);
413 /* currently the hash values include a challenge-response as well */
414 case AUTH_PASSWORD_HASH
:
415 case AUTH_PASSWORD_RESPONSE
:
416 nt_status
= cli_session_setup(
417 cli
, user_info
->client
.account_name
,
418 (char *)user_info
->password
.response
.lanman
.data
,
419 user_info
->password
.response
.lanman
.length
,
420 (char *)user_info
->password
.response
.nt
.data
,
421 user_info
->password
.response
.nt
.length
,
422 user_info
->mapped
.domain_name
);
425 DEBUG(0,("user_info constructed for user '%s' was invalid - password_state=%u invalid.\n",user_info
->mapped
.account_name
, user_info
->password_state
));
426 nt_status
= NT_STATUS_INTERNAL_ERROR
;
429 if (!NT_STATUS_IS_OK(nt_status
)) {
430 DEBUG(1,("password server %s rejected the password: %s\n",
431 cli_state_remote_name(cli
), nt_errstr(nt_status
)));
434 /* if logged in as guest then reject */
435 if (cli
->is_guestlogin
) {
436 DEBUG(1,("password server %s gave us guest only\n",
437 cli_state_remote_name(cli
)));
438 nt_status
= NT_STATUS_LOGON_FAILURE
;
443 if (NT_STATUS_IS_OK(nt_status
)) {
444 char *real_username
= NULL
;
445 struct passwd
*pass
= NULL
;
447 if ( (pass
= smb_getpwnam(talloc_tos(), user_info
->mapped
.account_name
,
448 &real_username
, True
)) != NULL
)
450 nt_status
= make_server_info_pw(server_info
, pass
->pw_name
, pass
);
452 TALLOC_FREE(real_username
);
456 nt_status
= NT_STATUS_NO_SUCH_USER
;
460 if (locally_made_cli
) {
467 static NTSTATUS
auth_init_smbserver(struct auth_context
*auth_context
, const char* param
, auth_methods
**auth_method
)
469 struct auth_methods
*result
;
471 result
= talloc_zero(auth_context
, struct auth_methods
);
472 if (result
== NULL
) {
473 return NT_STATUS_NO_MEMORY
;
475 result
->name
= "smbserver";
476 result
->auth
= check_smbserver_security
;
477 result
->get_chal
= auth_get_challenge_server
;
479 *auth_method
= result
;
483 NTSTATUS
auth_server_init(void)
485 return smb_register_auth(AUTH_INTERFACE_VERSION
, "smbserver", auth_init_smbserver
);