summaryrefslogtreecommitdiffstats
path: root/source3/auth/check_samsec.c
blob: 1e55fedb6151012201ead2df53d84153d6dc9598 (plain)
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
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
/*
   Unix SMB/CIFS implementation.
   Password and authentication handling
   Copyright (C) Andrew Tridgell              1992-2000
   Copyright (C) Luke Kenneth Casson Leighton 1996-2000
   Copyright (C) Andrew Bartlett              2001-2003
   Copyright (C) Gerald Carter                2003

   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 3 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, see <http://www.gnu.org/licenses/>.
*/

#include "includes.h"
#include "auth.h"
#include "../libcli/auth/libcli_auth.h"
#include "passdb.h"
#include "lib/util/memcache.h"

#undef DBGC_CLASS
#define DBGC_CLASS DBGC_AUTH

/****************************************************************************
 Do a specific test for an smb password being correct, given a smb_password and
 the lanman and NT responses.
****************************************************************************/

static NTSTATUS 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)
{
	NTSTATUS status;
	struct samr_Password _lm_hash, _nt_hash;
	struct samr_Password *lm_hash = NULL;
	struct samr_Password *nt_hash = NULL;

	*user_sess_key = data_blob_null;
	*lm_sess_key = data_blob_null;

	if (acct_ctrl & ACB_PWNOTREQ) {
		if (lp_null_passwords()) {
			DEBUG(3,("Account for user '%s' has no password and null passwords are allowed.\n", username));
			return NT_STATUS_OK;
		} else {
			DEBUG(3,("Account for user '%s' has no password and null passwords are NOT allowed.\n", username));
			return NT_STATUS_LOGON_FAILURE;
		}
	}

	if (lm_pw) {
		memcpy(_lm_hash.hash, lm_pw, sizeof(_lm_hash.hash));
		lm_hash = &_lm_hash;
	}
	if (nt_pw) {
		memcpy(_nt_hash.hash, nt_pw, sizeof(_nt_hash.hash));
		nt_hash = &_nt_hash;
	}
	switch (user_info->password_state) {
	case AUTH_PASSWORD_HASH:
		status = hash_password_check(mem_ctx, lp_lanman_auth(),
					     lp_ntlm_auth(),
					     user_info->password.hash.lanman,
					     user_info->password.hash.nt,
					     username,
					     lm_hash,
					     nt_hash);
		if (NT_STATUS_IS_OK(status)) {
			if (nt_pw) {
				*user_sess_key = data_blob_talloc(mem_ctx, NULL, 16);
				if (!user_sess_key->data) {
					status = NT_STATUS_NO_MEMORY;
					goto done;
				}
				SMBsesskeygen_ntv1(nt_pw, user_sess_key->data);
			}
		}
		break;

	/* Eventually we should test plaintext passwords in their own
	 * function, not assuming the caller has done a
	 * mapping */
	case AUTH_PASSWORD_PLAIN:
	case AUTH_PASSWORD_RESPONSE:
		status = ntlm_password_check(mem_ctx, lp_lanman_auth(),
					   lp_ntlm_auth(),
					   user_info->logon_parameters,
					   challenge,
					   &user_info->password.response.lanman, &user_info->password.response.nt,
					   username,
					   user_info->client.account_name,
					   user_info->client.domain_name,
					   lm_hash,
					   nt_hash,
					   user_sess_key, lm_sess_key);
		break;
	default:
		DEBUG(0,("user_info constructed for user '%s' was invalid - password_state=%u invalid.\n", username, user_info->password_state));
		status = NT_STATUS_INTERNAL_ERROR;
	}
done:
	ZERO_STRUCTP(lm_hash);
	ZERO_STRUCTP(nt_hash);
	return status;
}

/****************************************************************************
 Check if a user is allowed to logon at this time. Note this is the
 servers local time, as logon hours are just specified as a weekly
 bitmask.
****************************************************************************/

static bool logon_hours_ok(struct samu *sampass)
{
	/* In logon hours first bit is Sunday from 12AM to 1AM */
	const uint8_t *hours;
	struct tm *utctime;
	time_t lasttime;
	const char *asct;
	uint8_t bitmask, bitpos;

	hours = pdb_get_hours(sampass);
	if (!hours) {
		DEBUG(5,("logon_hours_ok: No hours restrictions for user %s\n",pdb_get_username(sampass)));
		return True;
	}

	lasttime = time(NULL);
	utctime = gmtime(&lasttime);
	if (!utctime) {
		DEBUG(1, ("logon_hours_ok: failed to get gmtime. Failing logon for user %s\n",
			pdb_get_username(sampass) ));
		return False;
	}

	/* find the corresponding byte and bit */
	bitpos = (utctime->tm_wday * 24 + utctime->tm_hour) % 168;
	bitmask = 1 << (bitpos % 8);

	if (! (hours[bitpos/8] & bitmask)) {
		struct tm *t = localtime(&lasttime);
		if (!t) {
			asct = "INVALID TIME";
		} else {
			asct = asctime(t);
			if (!asct) {
				asct = "INVALID TIME";
			}
		}

		DEBUG(1, ("logon_hours_ok: Account for user %s not allowed to "
			  "logon at this time (%s).\n",
			  pdb_get_username(sampass), asct ));
		return False;
	}

	asct = asctime(utctime);
	DEBUG(5,("logon_hours_ok: user %s allowed to logon at this time (%s)\n",
		pdb_get_username(sampass), asct ? asct : "UNKNOWN TIME" ));

	return True;
}

/****************************************************************************
 Do a specific test for a struct samu being valid for this connection
 (ie not disabled, expired and the like).
****************************************************************************/

static NTSTATUS sam_account_ok(TALLOC_CTX *mem_ctx,
			       struct samu *sampass,
			       const struct auth_usersupplied_info *user_info)
{
	uint32_t acct_ctrl = pdb_get_acct_ctrl(sampass);
	char *workstation_list;
	time_t kickoff_time;

	DEBUG(4,("sam_account_ok: Checking SMB password for user %s\n",pdb_get_username(sampass)));

	/* Quit if the account was disabled. */
	if (acct_ctrl & ACB_DISABLED) {
		DEBUG(1,("sam_account_ok: Account for user '%s' was disabled.\n", pdb_get_username(sampass)));
		return NT_STATUS_ACCOUNT_DISABLED;
	}

	/* Quit if the account was locked out. */
	if (acct_ctrl & ACB_AUTOLOCK) {
		DEBUG(1,("sam_account_ok: Account for user %s was locked out.\n", pdb_get_username(sampass)));
		return NT_STATUS_ACCOUNT_LOCKED_OUT;
	}

	/* Quit if the account is not allowed to logon at this time. */
	if (! logon_hours_ok(sampass)) {
		return NT_STATUS_INVALID_LOGON_HOURS;
	}

	/* Test account expire time */

	kickoff_time = pdb_get_kickoff_time(sampass);
	if (kickoff_time != 0 && time(NULL) > kickoff_time) {
		DEBUG(1,("sam_account_ok: Account for user '%s' has expired.\n", pdb_get_username(sampass)));
		DEBUG(3,("sam_account_ok: Account expired at '%ld' unix time.\n", (long)kickoff_time));
		return NT_STATUS_ACCOUNT_EXPIRED;
	}

	if (!(pdb_get_acct_ctrl(sampass) & ACB_PWNOEXP) && !(pdb_get_acct_ctrl(sampass) & ACB_PWNOTREQ)) {
		time_t must_change_time = pdb_get_pass_must_change_time(sampass);
		time_t last_set_time = pdb_get_pass_last_set_time(sampass);

		/* check for immediate expiry "must change at next logon"
		 * for a user account. */
		if (((acct_ctrl & (ACB_WSTRUST|ACB_SVRTRUST)) == 0) && (last_set_time == 0)) {
			DEBUG(1,("sam_account_ok: Account for user '%s' password must change!\n", pdb_get_username(sampass)));
			return NT_STATUS_PASSWORD_MUST_CHANGE;
		}

		/* check for expired password */
		if (must_change_time < time(NULL) && must_change_time != 0) {
			DEBUG(1,("sam_account_ok: Account for user '%s' password expired!\n", pdb_get_username(sampass)));
			DEBUG(1,("sam_account_ok: Password expired at '%s' (%ld) unix time.\n", http_timestring(talloc_tos(), must_change_time), (long)must_change_time));
			return NT_STATUS_PASSWORD_EXPIRED;
		}
	}

	/* Test workstation. Workstation list is comma separated. */

	workstation_list = talloc_strdup(mem_ctx, pdb_get_workstations(sampass));
	if (!workstation_list)
		return NT_STATUS_NO_MEMORY;

	if (*workstation_list) {
		bool invalid_ws = True;
		char *tok = NULL;
		const char *s = workstation_list;
		char *machine_name = talloc_asprintf(mem_ctx, "%s$", user_info->workstation_name);

		if (machine_name == NULL)
			return NT_STATUS_NO_MEMORY;

		while (next_token_talloc(mem_ctx, &s, &tok, ",")) {
			DEBUG(10,("sam_account_ok: checking for workstation match %s and %s\n",
				  tok, user_info->workstation_name));
			if(strequal(tok, user_info->workstation_name)) {
				invalid_ws = False;
				break;
			}
			if (tok[0] == '+') {
				DEBUG(10,("sam_account_ok: checking for workstation %s in group: %s\n",
					machine_name, tok + 1));
				if (user_in_group(machine_name, tok + 1)) {
					invalid_ws = False;
					break;
				}
			}
			TALLOC_FREE(tok);
		}
		TALLOC_FREE(tok);
		TALLOC_FREE(machine_name);

		if (invalid_ws)
			return NT_STATUS_INVALID_WORKSTATION;
	}

	if (acct_ctrl & ACB_DOMTRUST) {
		DEBUG(2,("sam_account_ok: Domain trust account %s denied by server\n", pdb_get_username(sampass)));
		return NT_STATUS_NOLOGON_INTERDOMAIN_TRUST_ACCOUNT;
	}

	if (acct_ctrl & ACB_SVRTRUST) {
		if (!(user_info->logon_parameters & MSV1_0_ALLOW_SERVER_TRUST_ACCOUNT)) {
			DEBUG(2,("sam_account_ok: Server trust account %s denied by server\n", pdb_get_username(sampass)));
			return NT_STATUS_NOLOGON_SERVER_TRUST_ACCOUNT;
		}
	}

	if (acct_ctrl & ACB_WSTRUST) {
		if (!(user_info->logon_parameters & MSV1_0_ALLOW_WORKSTATION_TRUST_ACCOUNT)) {
			DEBUG(2,("sam_account_ok: Wksta trust account %s denied by server\n", pdb_get_username(sampass)));
			return NT_STATUS_NOLOGON_WORKSTATION_TRUST_ACCOUNT;
		}
	}
	return NT_STATUS_OK;
}

/**
 * Check whether the given password is one of the last two
 * password history entries. If so, the bad pwcount should
 * not be incremented even though the actual password check
 * failed.
 */
static bool need_to_increment_bad_pw_count(
	const DATA_BLOB *challenge,
	struct samu* sampass,
	const struct auth_usersupplied_info *user_info)
{
	uint8_t i;
	const uint8_t *pwhistory;
	uint32_t pwhistory_len;
	uint32_t policy_pwhistory_len;
	uint32_t acct_ctrl;
	const char *username;
	TALLOC_CTX *mem_ctx = talloc_stackframe();
	bool result = true;

	pdb_get_account_policy(PDB_POLICY_PASSWORD_HISTORY,
			       &policy_pwhistory_len);
	if (policy_pwhistory_len == 0) {
		goto done;
	}

	pwhistory = pdb_get_pw_history(sampass, &pwhistory_len);
	if (!pwhistory || pwhistory_len == 0) {
		goto done;
	}

	acct_ctrl = pdb_get_acct_ctrl(sampass);
	username = pdb_get_username(sampass);

	for (i=1; i < MIN(MIN(3, policy_pwhistory_len), pwhistory_len); i++) {
		const uint8_t *salt;
		const uint8_t *nt_pw;
		NTSTATUS status;
		DATA_BLOB user_sess_key = data_blob_null;
		DATA_BLOB lm_sess_key = data_blob_null;

		salt = &pwhistory[i*PW_HISTORY_ENTRY_LEN];
		nt_pw = salt + PW_HISTORY_SALT_LEN;

		if (all_zero(nt_pw, NT_HASH_LEN)) {
			/* skip zero password hash */
			continue;
		}

		if (!all_zero(salt, PW_HISTORY_SALT_LEN)) {
			/* skip nonzero salt (old format entry) */
			continue;
		}

		status = sam_password_ok(mem_ctx,
					 username, acct_ctrl,
					 challenge,
					 NULL, nt_pw,
					 user_info, &user_sess_key, &lm_sess_key);
		if (NT_STATUS_IS_OK(status)) {
			result = false;
			break;
		}
	}

done:
	TALLOC_FREE(mem_ctx);
	return result;
}

/****************************************************************************
check if a username/password is OK assuming the password is a 24 byte
SMB hash supplied in the user_info structure
return an NT_STATUS constant.
****************************************************************************/

NTSTATUS check_sam_security(const DATA_BLOB *challenge,
			    TALLOC_CTX *mem_ctx,
			    const struct auth_usersupplied_info *user_info,
			    struct auth_serversupplied_info **server_info)
{
	struct samu *sampass=NULL;
	bool ret;
	NTSTATUS nt_status;
	NTSTATUS update_login_attempts_status;
	DATA_BLOB user_sess_key = data_blob_null;
	DATA_BLOB lm_sess_key = data_blob_null;
	bool updated_badpw = False;
	const char *username;
	const uint8_t *nt_pw;
	const uint8_t *lm_pw;
	uint32_t acct_ctrl;
	char *mutex_name_by_user = NULL;
	struct named_mutex *mtx = NULL;

	/* the returned struct gets kept on the server_info, by means
	   of a steal further down */

	sampass = samu_new(mem_ctx);
	if (sampass == NULL) {
		return NT_STATUS_NO_MEMORY;
	}

	/* get the account information */

	become_root();
	ret = pdb_getsampwnam(sampass, user_info->mapped.account_name);
	unbecome_root();

	if (!ret) {
		DEBUG(3,("check_sam_security: Couldn't find user '%s' in "
			 "passdb.\n", user_info->mapped.account_name));
		TALLOC_FREE(sampass);
		return NT_STATUS_NO_SUCH_USER;
	}

	acct_ctrl = pdb_get_acct_ctrl(sampass);
	username = pdb_get_username(sampass);
	nt_pw = pdb_get_nt_passwd(sampass);
	lm_pw = pdb_get_lanman_passwd(sampass);

	/* Quit if the account was locked out. */
	if (acct_ctrl & ACB_AUTOLOCK) {
		DEBUG(3,("check_sam_security: Account for user %s was locked out.\n", username));
		TALLOC_FREE(sampass);
		return NT_STATUS_ACCOUNT_LOCKED_OUT;
	}

	nt_status = sam_password_ok(mem_ctx,
				    username, acct_ctrl,
				    challenge, lm_pw, nt_pw,
				    user_info, &user_sess_key, &lm_sess_key);

	/*
	 * We must re-load the sam account information under a mutex
	 * lock to ensure we don't miss any concurrent account lockout
	 * changes.
	 */

	/* Clear out old sampass info. */
	TALLOC_FREE(sampass);
	acct_ctrl = 0;
	username = NULL;
	nt_pw = NULL;
	lm_pw = NULL;

	sampass = samu_new(mem_ctx);
	if (sampass == NULL) {
		return NT_STATUS_NO_MEMORY;
	}

	mutex_name_by_user = talloc_asprintf(mem_ctx,
					     "check_sam_security_mutex_%s",
					     user_info->mapped.account_name);
	if (mutex_name_by_user == NULL) {
		nt_status = NT_STATUS_NO_MEMORY;
		goto done;
	}

	/* Grab the named mutex under root with 30 second timeout. */
	become_root();
	mtx = grab_named_mutex(mem_ctx, mutex_name_by_user, 30);
	if (mtx != NULL) {
		/* Re-load the account information if we got the mutex. */
		ret = pdb_getsampwnam(sampass, user_info->mapped.account_name);
	}
	unbecome_root();

	/* Everything from here on until mtx is freed is done under the mutex.*/

	if (mtx == NULL) {
		DBG_ERR("Acquisition of mutex %s failed "
			"for user %s\n",
			mutex_name_by_user,
			user_info->mapped.account_name);
		nt_status = NT_STATUS_INTERNAL_ERROR;
		goto done;
	}

	if (!ret) {
		/*
		 * Re-load of account failed. This could only happen if the
		 * user was deleted in the meantime.
		 */
		DBG_NOTICE("reload of user '%s' in passdb failed.\n",
			   user_info->mapped.account_name);
		nt_status = NT_STATUS_NO_SUCH_USER;
		goto done;
	}

	/* Re-load the account control info. */
	acct_ctrl = pdb_get_acct_ctrl(sampass);
	username = pdb_get_username(sampass);

	/*
	 * Check if the account is now locked out - now under the mutex.
	 * This can happen if the server is under
	 * a password guess attack and the ACB_AUTOLOCK is set by
	 * another process.
	 */
	if (acct_ctrl & ACB_AUTOLOCK) {
		DBG_NOTICE("Account for user %s was locked out.\n", username);
		nt_status = NT_STATUS_ACCOUNT_LOCKED_OUT;
		goto done;
	}

	/* Notify passdb backend of login success/failure. If not
	   NT_STATUS_OK the backend doesn't like the login */

	update_login_attempts_status = pdb_update_login_attempts(sampass, NT_STATUS_IS_OK(nt_status));

	if (!NT_STATUS_IS_OK(nt_status)) {
		bool increment_bad_pw_count = false;

		if (NT_STATUS_EQUAL(nt_status,NT_STATUS_WRONG_PASSWORD) &&
		    (acct_ctrl & ACB_NORMAL) &&
		    NT_STATUS_IS_OK(update_login_attempts_status))
		{
			increment_bad_pw_count =
				need_to_increment_bad_pw_count(
					challenge, sampass, user_info);
		}

		if (increment_bad_pw_count) {
			pdb_increment_bad_password_count(sampass);
			updated_badpw = True;
		} else {
			pdb_update_bad_password_count(sampass,
						      &updated_badpw);
		}
		if (updated_badpw){
			NTSTATUS status;

			become_root();
			status = pdb_update_sam_account(sampass);
			unbecome_root();

			if (!NT_STATUS_IS_OK(status)) {
				DEBUG(1, ("Failed to modify entry: %s\n",
					  nt_errstr(status)));
			}
		}
		goto done;
	}

	/*
	 * We must only reset the bad password count if the login was
	 * successful, including checking account policies
	 */
	nt_status = sam_account_ok(mem_ctx, sampass, user_info);
	if (!NT_STATUS_IS_OK(nt_status)) {
		goto done;
	}

	if ((acct_ctrl & ACB_NORMAL) &&
	    (pdb_get_bad_password_count(sampass) > 0)){
		NTSTATUS status;

		pdb_set_bad_password_count(sampass, 0, PDB_CHANGED);
		pdb_set_bad_password_time(sampass, 0, PDB_CHANGED);

		become_root();
		status = pdb_update_sam_account(sampass);
		unbecome_root();

		if (!NT_STATUS_IS_OK(status)) {
			DEBUG(1, ("Failed to modify entry: %s\n",
				  nt_errstr(status)));
		}
	}

	become_root();
	nt_status = make_server_info_sam(mem_ctx, sampass, server_info);
	unbecome_root();

	if (!NT_STATUS_IS_OK(nt_status)) {
		DEBUG(0,("check_sam_security: make_server_info_sam() failed with '%s'\n", nt_errstr(nt_status)));
		goto done;
	}

	(*server_info)->session_key =
		data_blob_talloc(*server_info, user_sess_key.data,
				 user_sess_key.length);
	data_blob_free(&user_sess_key);

	(*server_info)->lm_session_key =
		data_blob_talloc(*server_info, lm_sess_key.data,
				 lm_sess_key.length);
	data_blob_free(&lm_sess_key);

	(*server_info)->nss_token |= user_info->was_mapped;

done:
	/*
	 * Always flush the getpwsid cache or this will grow indefinitely for
	 * each NTLM auththentication.
	 */
	memcache_flush(NULL, PDB_GETPWSID_CACHE);
	TALLOC_FREE(sampass);
	data_blob_free(&user_sess_key);
	data_blob_free(&lm_sess_key);
	TALLOC_FREE(mutex_name_by_user);
	TALLOC_FREE(mtx);
	return nt_status;
}

/* This helper function for winbindd returns a very similar value to
 * what a NETLOGON call would give, without the indirection */
NTSTATUS check_sam_security_info3(const DATA_BLOB *challenge,
				  TALLOC_CTX *mem_ctx,
				  const struct auth_usersupplied_info *user_info,
				  struct netr_SamInfo3 **pinfo3)
{
	struct auth_serversupplied_info *server_info = NULL;
	struct netr_SamInfo3 *info3;
	NTSTATUS status;
	TALLOC_CTX *frame = talloc_stackframe();

	status = check_sam_security(challenge, talloc_tos(), user_info,
				    &server_info);
	if (!NT_STATUS_IS_OK(status)) {
		DEBUG(10, ("check_sam_security failed: %s\n",
			   nt_errstr(status)));
		goto done;
	}

	info3 = talloc_zero(mem_ctx, struct netr_SamInfo3);
	if (info3 == NULL) {
		status = NT_STATUS_NO_MEMORY;
		goto done;
	}

	status = serverinfo_to_SamInfo3(server_info, info3);
	if (!NT_STATUS_IS_OK(status)) {
		DEBUG(10, ("serverinfo_to_SamInfo3 failed: %s\n",
			   nt_errstr(status)));
		goto done;
	}
	*pinfo3 = info3;
	status =  NT_STATUS_OK;
done:
	TALLOC_FREE(frame);
	return status;
}