1 /*
2    Unix SMB/CIFS implementation.
3    Password and authentication handling
4    Copyright (C) Andrew Tridgell              1992-2000
5    Copyright (C) Luke Kenneth Casson Leighton 1996-2000
6    Copyright (C) Andrew Bartlett              2001-2003
7    Copyright (C) Gerald Carter                2003
8 
9    This program is free software; you can redistribute it and/or modify
10    it under the terms of the GNU General Public License as published by
11    the Free Software Foundation; either version 3 of the License, or
12    (at your option) any later version.
13 
14    This program is distributed in the hope that it will be useful,
15    but WITHOUT ANY WARRANTY; without even the implied warranty of
16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17    GNU General Public License for more details.
18 
19    You should have received a copy of the GNU General Public License
20    along with this program.  If not, see <http://www.gnu.org/licenses/>.
21 */
22 
23 #include "includes.h"
24 #include "auth.h"
25 #include "../libcli/auth/libcli_auth.h"
26 #include "passdb.h"
27 
28 #undef DBGC_CLASS
29 #define DBGC_CLASS DBGC_AUTH
30 
31 /****************************************************************************
32  Do a specific test for an smb password being correct, given a smb_password and
33  the lanman and NT responses.
34 ****************************************************************************/
35 
sam_password_ok(TALLOC_CTX * mem_ctx,const char * username,uint32_t acct_ctrl,const DATA_BLOB * challenge,const uint8_t * lm_pw,const uint8_t * nt_pw,const struct auth_usersupplied_info * user_info,DATA_BLOB * user_sess_key,DATA_BLOB * lm_sess_key)36 static NTSTATUS sam_password_ok(TALLOC_CTX *mem_ctx,
37 				const char *username,
38 				uint32_t acct_ctrl,
39 				const DATA_BLOB *challenge,
40 				const uint8_t *lm_pw,
41 				const uint8_t *nt_pw,
42 				const struct auth_usersupplied_info *user_info,
43 				DATA_BLOB *user_sess_key,
44 				DATA_BLOB *lm_sess_key)
45 {
46 	NTSTATUS status;
47 	struct samr_Password _lm_hash, _nt_hash;
48 	struct samr_Password *lm_hash = NULL;
49 	struct samr_Password *nt_hash = NULL;
50 
51 	*user_sess_key = data_blob_null;
52 	*lm_sess_key = data_blob_null;
53 
54 	if (acct_ctrl & ACB_PWNOTREQ) {
55 		if (lp_null_passwords()) {
56 			DEBUG(3,("Account for user '%s' has no password and null passwords are allowed.\n", username));
57 			return NT_STATUS_OK;
58 		} else {
59 			DEBUG(3,("Account for user '%s' has no password and null passwords are NOT allowed.\n", username));
60 			return NT_STATUS_LOGON_FAILURE;
61 		}
62 	}
63 
64 	if (lm_pw) {
65 		memcpy(_lm_hash.hash, lm_pw, sizeof(_lm_hash.hash));
66 		lm_hash = &_lm_hash;
67 	}
68 	if (nt_pw) {
69 		memcpy(_nt_hash.hash, nt_pw, sizeof(_nt_hash.hash));
70 		nt_hash = &_nt_hash;
71 	}
72 	switch (user_info->password_state) {
73 	case AUTH_PASSWORD_HASH:
74 		status = hash_password_check(mem_ctx, lp_lanman_auth(),
75 					     user_info->password.hash.lanman,
76 					     user_info->password.hash.nt,
77 					     username,
78 					     lm_hash,
79 					     nt_hash);
80 		if (NT_STATUS_IS_OK(status)) {
81 			if (nt_pw) {
82 				*user_sess_key = data_blob_talloc(mem_ctx, NULL, 16);
83 				if (!user_sess_key->data) {
84 					return NT_STATUS_NO_MEMORY;
85 				}
86 				SMBsesskeygen_ntv1(nt_pw, user_sess_key->data);
87 			}
88 		}
89 		return status;
90 
91 	/* Eventually we should test plaintext passwords in their own
92 	 * function, not assuming the caller has done a
93 	 * mapping */
94 	case AUTH_PASSWORD_PLAIN:
95 	case AUTH_PASSWORD_RESPONSE:
96 		return ntlm_password_check(mem_ctx, lp_lanman_auth(),
97 					   lp_ntlm_auth(),
98 					   user_info->logon_parameters,
99 					   challenge,
100 					   &user_info->password.response.lanman, &user_info->password.response.nt,
101 					   username,
102 					   user_info->client.account_name,
103 					   user_info->client.domain_name,
104 					   lm_hash,
105 					   nt_hash,
106 					   user_sess_key, lm_sess_key);
107 	default:
108 		DEBUG(0,("user_info constructed for user '%s' was invalid - password_state=%u invalid.\n", username, user_info->password_state));
109 		return NT_STATUS_INTERNAL_ERROR;
110 	}
111 }
112 
113 /****************************************************************************
114  Check if a user is allowed to logon at this time. Note this is the
115  servers local time, as logon hours are just specified as a weekly
116  bitmask.
117 ****************************************************************************/
118 
logon_hours_ok(struct samu * sampass)119 static bool logon_hours_ok(struct samu *sampass)
120 {
121 	/* In logon hours first bit is Sunday from 12AM to 1AM */
122 	const uint8_t *hours;
123 	struct tm *utctime;
124 	time_t lasttime;
125 	const char *asct;
126 	uint8_t bitmask, bitpos;
127 
128 	hours = pdb_get_hours(sampass);
129 	if (!hours) {
130 		DEBUG(5,("logon_hours_ok: No hours restrictions for user %s\n",pdb_get_username(sampass)));
131 		return True;
132 	}
133 
134 	lasttime = time(NULL);
135 	utctime = gmtime(&lasttime);
136 	if (!utctime) {
137 		DEBUG(1, ("logon_hours_ok: failed to get gmtime. Failing logon for user %s\n",
138 			pdb_get_username(sampass) ));
139 		return False;
140 	}
141 
142 	/* find the corresponding byte and bit */
143 	bitpos = (utctime->tm_wday * 24 + utctime->tm_hour) % 168;
144 	bitmask = 1 << (bitpos % 8);
145 
146 	if (! (hours[bitpos/8] & bitmask)) {
147 		struct tm *t = localtime(&lasttime);
148 		if (!t) {
149 			asct = "INVALID TIME";
150 		} else {
151 			asct = asctime(t);
152 			if (!asct) {
153 				asct = "INVALID TIME";
154 			}
155 		}
156 
157 		DEBUG(1, ("logon_hours_ok: Account for user %s not allowed to "
158 			  "logon at this time (%s).\n",
159 			  pdb_get_username(sampass), asct ));
160 		return False;
161 	}
162 
163 	asct = asctime(utctime);
164 	DEBUG(5,("logon_hours_ok: user %s allowed to logon at this time (%s)\n",
165 		pdb_get_username(sampass), asct ? asct : "UNKNOWN TIME" ));
166 
167 	return True;
168 }
169 
170 /****************************************************************************
171  Do a specific test for a struct samu being valid for this connection
172  (ie not disabled, expired and the like).
173 ****************************************************************************/
174 
sam_account_ok(TALLOC_CTX * mem_ctx,struct samu * sampass,const struct auth_usersupplied_info * user_info)175 static NTSTATUS sam_account_ok(TALLOC_CTX *mem_ctx,
176 			       struct samu *sampass,
177 			       const struct auth_usersupplied_info *user_info)
178 {
179 	uint32_t acct_ctrl = pdb_get_acct_ctrl(sampass);
180 	char *workstation_list;
181 	time_t kickoff_time;
182 
183 	DEBUG(4,("sam_account_ok: Checking SMB password for user %s\n",pdb_get_username(sampass)));
184 
185 	/* Quit if the account was disabled. */
186 	if (acct_ctrl & ACB_DISABLED) {
187 		DEBUG(1,("sam_account_ok: Account for user '%s' was disabled.\n", pdb_get_username(sampass)));
188 		return NT_STATUS_ACCOUNT_DISABLED;
189 	}
190 
191 	/* Quit if the account was locked out. */
192 	if (acct_ctrl & ACB_AUTOLOCK) {
193 		DEBUG(1,("sam_account_ok: Account for user %s was locked out.\n", pdb_get_username(sampass)));
194 		return NT_STATUS_ACCOUNT_LOCKED_OUT;
195 	}
196 
197 	/* Quit if the account is not allowed to logon at this time. */
198 	if (! logon_hours_ok(sampass)) {
199 		return NT_STATUS_INVALID_LOGON_HOURS;
200 	}
201 
202 	/* Test account expire time */
203 
204 	kickoff_time = pdb_get_kickoff_time(sampass);
205 	if (kickoff_time != 0 && time(NULL) > kickoff_time) {
206 		DEBUG(1,("sam_account_ok: Account for user '%s' has expired.\n", pdb_get_username(sampass)));
207 		DEBUG(3,("sam_account_ok: Account expired at '%ld' unix time.\n", (long)kickoff_time));
208 		return NT_STATUS_ACCOUNT_EXPIRED;
209 	}
210 
211 	if (!(pdb_get_acct_ctrl(sampass) & ACB_PWNOEXP) && !(pdb_get_acct_ctrl(sampass) & ACB_PWNOTREQ)) {
212 		time_t must_change_time = pdb_get_pass_must_change_time(sampass);
213 		time_t last_set_time = pdb_get_pass_last_set_time(sampass);
214 
215 		/* check for immediate expiry "must change at next logon"
216 		 * for a user account. */
217 		if (((acct_ctrl & (ACB_WSTRUST|ACB_SVRTRUST)) == 0) && (last_set_time == 0)) {
218 			DEBUG(1,("sam_account_ok: Account for user '%s' password must change!\n", pdb_get_username(sampass)));
219 			return NT_STATUS_PASSWORD_MUST_CHANGE;
220 		}
221 
222 		/* check for expired password */
223 		if (must_change_time < time(NULL) && must_change_time != 0) {
224 			DEBUG(1,("sam_account_ok: Account for user '%s' password expired!\n", pdb_get_username(sampass)));
225 			DEBUG(1,("sam_account_ok: Password expired at '%s' (%ld) unix time.\n", http_timestring(talloc_tos(), must_change_time), (long)must_change_time));
226 			return NT_STATUS_PASSWORD_EXPIRED;
227 		}
228 	}
229 
230 	/* Test workstation. Workstation list is comma separated. */
231 
232 	workstation_list = talloc_strdup(mem_ctx, pdb_get_workstations(sampass));
233 	if (!workstation_list)
234 		return NT_STATUS_NO_MEMORY;
235 
236 	if (*workstation_list) {
237 		bool invalid_ws = True;
238 		char *tok = NULL;
239 		const char *s = workstation_list;
240 		char *machine_name = talloc_asprintf(mem_ctx, "%s$", user_info->workstation_name);
241 
242 		if (machine_name == NULL)
243 			return NT_STATUS_NO_MEMORY;
244 
245 		while (next_token_talloc(mem_ctx, &s, &tok, ",")) {
246 			DEBUG(10,("sam_account_ok: checking for workstation match %s and %s\n",
247 				  tok, user_info->workstation_name));
248 			if(strequal(tok, user_info->workstation_name)) {
249 				invalid_ws = False;
250 				break;
251 			}
252 			if (tok[0] == '+') {
253 				DEBUG(10,("sam_account_ok: checking for workstation %s in group: %s\n",
254 					machine_name, tok + 1));
255 				if (user_in_group(machine_name, tok + 1)) {
256 					invalid_ws = False;
257 					break;
258 				}
259 			}
260 			TALLOC_FREE(tok);
261 		}
262 		TALLOC_FREE(tok);
263 		TALLOC_FREE(machine_name);
264 
265 		if (invalid_ws)
266 			return NT_STATUS_INVALID_WORKSTATION;
267 	}
268 
269 	if (acct_ctrl & ACB_DOMTRUST) {
270 		DEBUG(2,("sam_account_ok: Domain trust account %s denied by server\n", pdb_get_username(sampass)));
271 		return NT_STATUS_NOLOGON_INTERDOMAIN_TRUST_ACCOUNT;
272 	}
273 
274 	if (acct_ctrl & ACB_SVRTRUST) {
275 		if (!(user_info->logon_parameters & MSV1_0_ALLOW_SERVER_TRUST_ACCOUNT)) {
276 			DEBUG(2,("sam_account_ok: Server trust account %s denied by server\n", pdb_get_username(sampass)));
277 			return NT_STATUS_NOLOGON_SERVER_TRUST_ACCOUNT;
278 		}
279 	}
280 
281 	if (acct_ctrl & ACB_WSTRUST) {
282 		if (!(user_info->logon_parameters & MSV1_0_ALLOW_WORKSTATION_TRUST_ACCOUNT)) {
283 			DEBUG(2,("sam_account_ok: Wksta trust account %s denied by server\n", pdb_get_username(sampass)));
284 			return NT_STATUS_NOLOGON_WORKSTATION_TRUST_ACCOUNT;
285 		}
286 	}
287 	return NT_STATUS_OK;
288 }
289 
290 /**
291  * Check whether the given password is one of the last two
292  * password history entries. If so, the bad pwcount should
293  * not be incremented even thought the actual password check
294  * failed.
295  */
need_to_increment_bad_pw_count(const DATA_BLOB * challenge,struct samu * sampass,const struct auth_usersupplied_info * user_info)296 static bool need_to_increment_bad_pw_count(
297 	const DATA_BLOB *challenge,
298 	struct samu* sampass,
299 	const struct auth_usersupplied_info *user_info)
300 {
301 	uint8_t i;
302 	const uint8_t *pwhistory;
303 	uint32_t pwhistory_len;
304 	uint32_t policy_pwhistory_len;
305 	uint32_t acct_ctrl;
306 	const char *username;
307 	TALLOC_CTX *mem_ctx = talloc_stackframe();
308 	bool result = true;
309 
310 	pdb_get_account_policy(PDB_POLICY_PASSWORD_HISTORY,
311 			       &policy_pwhistory_len);
312 	if (policy_pwhistory_len == 0) {
313 		goto done;
314 	}
315 
316 	pwhistory = pdb_get_pw_history(sampass, &pwhistory_len);
317 	if (!pwhistory || pwhistory_len == 0) {
318 		goto done;
319 	}
320 
321 	acct_ctrl = pdb_get_acct_ctrl(sampass);
322 	username = pdb_get_username(sampass);
323 
324 	for (i=1; i < MIN(MIN(3, policy_pwhistory_len), pwhistory_len); i++) {
325 		const uint8_t *salt;
326 		const uint8_t *nt_pw;
327 		NTSTATUS status;
328 		DATA_BLOB user_sess_key = data_blob_null;
329 		DATA_BLOB lm_sess_key = data_blob_null;
330 
331 		salt = &pwhistory[i*PW_HISTORY_ENTRY_LEN];
332 		nt_pw = salt + PW_HISTORY_SALT_LEN;
333 
334 		if (all_zero(nt_pw, NT_HASH_LEN)) {
335 			/* skip zero password hash */
336 			continue;
337 		}
338 
339 		if (!all_zero(salt, PW_HISTORY_SALT_LEN)) {
340 			/* skip nonzero salt (old format entry) */
341 			continue;
342 		}
343 
344 		status = sam_password_ok(mem_ctx,
345 					 username, acct_ctrl,
346 					 challenge,
347 					 NULL, nt_pw,
348 					 user_info, &user_sess_key, &lm_sess_key);
349 		if (NT_STATUS_IS_OK(status)) {
350 			result = false;
351 			break;
352 		}
353 	}
354 
355 done:
356 	TALLOC_FREE(mem_ctx);
357 	return result;
358 }
359 
360 /****************************************************************************
361 check if a username/password is OK assuming the password is a 24 byte
362 SMB hash supplied in the user_info structure
363 return an NT_STATUS constant.
364 ****************************************************************************/
365 
check_sam_security(const DATA_BLOB * challenge,TALLOC_CTX * mem_ctx,const struct auth_usersupplied_info * user_info,struct auth_serversupplied_info ** server_info)366 NTSTATUS check_sam_security(const DATA_BLOB *challenge,
367 			    TALLOC_CTX *mem_ctx,
368 			    const struct auth_usersupplied_info *user_info,
369 			    struct auth_serversupplied_info **server_info)
370 {
371 	struct samu *sampass=NULL;
372 	bool ret;
373 	NTSTATUS nt_status;
374 	NTSTATUS update_login_attempts_status;
375 	DATA_BLOB user_sess_key = data_blob_null;
376 	DATA_BLOB lm_sess_key = data_blob_null;
377 	bool updated_badpw = False;
378 	const char *username;
379 	const uint8_t *nt_pw;
380 	const uint8_t *lm_pw;
381 	uint32_t acct_ctrl;
382 
383 	/* the returned struct gets kept on the server_info, by means
384 	   of a steal further down */
385 
386 	sampass = samu_new(mem_ctx);
387 	if (sampass == NULL) {
388 		return NT_STATUS_NO_MEMORY;
389 	}
390 
391 	/* get the account information */
392 
393 	become_root();
394 	ret = pdb_getsampwnam(sampass, user_info->mapped.account_name);
395 	unbecome_root();
396 
397 	if (ret == False) {
398 		DEBUG(3,("check_sam_security: Couldn't find user '%s' in "
399 			 "passdb.\n", user_info->mapped.account_name));
400 		TALLOC_FREE(sampass);
401 		return NT_STATUS_NO_SUCH_USER;
402 	}
403 
404 	acct_ctrl = pdb_get_acct_ctrl(sampass);
405 	username = pdb_get_username(sampass);
406 	nt_pw = pdb_get_nt_passwd(sampass);
407 	lm_pw = pdb_get_lanman_passwd(sampass);
408 
409 	/* Quit if the account was locked out. */
410 	if (acct_ctrl & ACB_AUTOLOCK) {
411 		DEBUG(3,("check_sam_security: Account for user %s was locked out.\n", username));
412 		TALLOC_FREE(sampass);
413 		return NT_STATUS_ACCOUNT_LOCKED_OUT;
414 	}
415 
416 	nt_status = sam_password_ok(mem_ctx,
417 				    username, acct_ctrl,
418 				    challenge, lm_pw, nt_pw,
419 				    user_info, &user_sess_key, &lm_sess_key);
420 
421 	/* Notify passdb backend of login success/failure. If not
422 	   NT_STATUS_OK the backend doesn't like the login */
423 
424 	update_login_attempts_status = pdb_update_login_attempts(sampass, NT_STATUS_IS_OK(nt_status));
425 
426 	if (!NT_STATUS_IS_OK(nt_status)) {
427 		bool increment_bad_pw_count = false;
428 
429 		if (NT_STATUS_EQUAL(nt_status,NT_STATUS_WRONG_PASSWORD) &&
430 		    (acct_ctrl & ACB_NORMAL) &&
431 		    NT_STATUS_IS_OK(update_login_attempts_status))
432 		{
433 			increment_bad_pw_count =
434 				need_to_increment_bad_pw_count(
435 					challenge, sampass, user_info);
436 		}
437 
438 		if (increment_bad_pw_count) {
439 			pdb_increment_bad_password_count(sampass);
440 			updated_badpw = True;
441 		} else {
442 			pdb_update_bad_password_count(sampass,
443 						      &updated_badpw);
444 		}
445 		if (updated_badpw){
446 			NTSTATUS status;
447 
448 			become_root();
449 			status = pdb_update_sam_account(sampass);
450 			unbecome_root();
451 
452 			if (!NT_STATUS_IS_OK(status)) {
453 				DEBUG(1, ("Failed to modify entry: %s\n",
454 					  nt_errstr(status)));
455 			}
456 		}
457 		goto done;
458 	}
459 
460 	/*
461 	 * We must only reset the bad password count if the login was
462 	 * successful, including checking account policies
463 	 */
464 	nt_status = sam_account_ok(mem_ctx, sampass, user_info);
465 	if (!NT_STATUS_IS_OK(nt_status)) {
466 		goto done;
467 	}
468 
469 	if ((acct_ctrl & ACB_NORMAL) &&
470 	    (pdb_get_bad_password_count(sampass) > 0)){
471 		NTSTATUS status;
472 
473 		pdb_set_bad_password_count(sampass, 0, PDB_CHANGED);
474 		pdb_set_bad_password_time(sampass, 0, PDB_CHANGED);
475 
476 		become_root();
477 		status = pdb_update_sam_account(sampass);
478 		unbecome_root();
479 
480 		if (!NT_STATUS_IS_OK(status)) {
481 			DEBUG(1, ("Failed to modify entry: %s\n",
482 				  nt_errstr(status)));
483 		}
484 	}
485 
486 	become_root();
487 	nt_status = make_server_info_sam(mem_ctx, sampass, server_info);
488 	unbecome_root();
489 
490 	TALLOC_FREE(sampass);
491 
492 	if (!NT_STATUS_IS_OK(nt_status)) {
493 		DEBUG(0,("check_sam_security: make_server_info_sam() failed with '%s'\n", nt_errstr(nt_status)));
494 		goto done;
495 	}
496 
497 	(*server_info)->session_key =
498 		data_blob_talloc(*server_info, user_sess_key.data,
499 				 user_sess_key.length);
500 	data_blob_free(&user_sess_key);
501 
502 	(*server_info)->lm_session_key =
503 		data_blob_talloc(*server_info, lm_sess_key.data,
504 				 lm_sess_key.length);
505 	data_blob_free(&lm_sess_key);
506 
507 	(*server_info)->nss_token |= user_info->was_mapped;
508 
509 done:
510 	TALLOC_FREE(sampass);
511 	data_blob_free(&user_sess_key);
512 	data_blob_free(&lm_sess_key);
513 	return nt_status;
514 }
515 
516 /* This helper function for winbindd returns a very similar value to
517  * what a NETLOGON call would give, without the indirection */
check_sam_security_info3(const DATA_BLOB * challenge,TALLOC_CTX * mem_ctx,const struct auth_usersupplied_info * user_info,struct netr_SamInfo3 ** pinfo3)518 NTSTATUS check_sam_security_info3(const DATA_BLOB *challenge,
519 				  TALLOC_CTX *mem_ctx,
520 				  const struct auth_usersupplied_info *user_info,
521 				  struct netr_SamInfo3 **pinfo3)
522 {
523 	struct auth_serversupplied_info *server_info = NULL;
524 	struct netr_SamInfo3 *info3;
525 	NTSTATUS status;
526 	TALLOC_CTX *frame = talloc_stackframe();
527 
528 	status = check_sam_security(challenge, talloc_tos(), user_info,
529 				    &server_info);
530 	if (!NT_STATUS_IS_OK(status)) {
531 		DEBUG(10, ("check_sam_security failed: %s\n",
532 			   nt_errstr(status)));
533 		goto done;
534 	}
535 
536 	info3 = talloc_zero(mem_ctx, struct netr_SamInfo3);
537 	if (info3 == NULL) {
538 		status = NT_STATUS_NO_MEMORY;
539 		goto done;
540 	}
541 
542 	status = serverinfo_to_SamInfo3(server_info, info3);
543 	if (!NT_STATUS_IS_OK(status)) {
544 		DEBUG(10, ("serverinfo_to_SamInfo3 failed: %s\n",
545 			   nt_errstr(status)));
546 		goto done;
547 	}
548 	*pinfo3 = info3;
549 	status =  NT_STATUS_OK;
550 done:
551 	TALLOC_FREE(frame);
552 	return status;
553 }
554