summaryrefslogtreecommitdiff
path: root/source3/libads/authdata.c
blob: ef5400654e943520b52ed3c461e187b9904693fa (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
/*
   Unix SMB/CIFS implementation.
   kerberos authorization data (PAC) utility library
   Copyright (C) Jim McDonough <jmcd@us.ibm.com> 2003
   Copyright (C) Andrew Bartlett <abartlet@samba.org> 2004-2005
   Copyright (C) Andrew Tridgell 2001
   Copyright (C) Luke Howard 2002-2003
   Copyright (C) Stefan Metzmacher 2004-2005
   Copyright (C) Guenther Deschner 2005,2007,2008

   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 "librpc/gen_ndr/ndr_krb5pac.h"

#ifdef HAVE_KRB5

/****************************************************************
****************************************************************/

static krb5_error_code check_pac_checksum(TALLOC_CTX *mem_ctx,
					  DATA_BLOB pac_data,
					  struct PAC_SIGNATURE_DATA *sig,
					  krb5_context context,
					  krb5_keyblock *keyblock)
{
	krb5_error_code ret;
	krb5_checksum cksum;
	krb5_keyusage usage = 0;

	smb_krb5_checksum_from_pac_sig(&cksum, sig);

#ifdef HAVE_KRB5_KU_OTHER_CKSUM /* Heimdal */
	usage = KRB5_KU_OTHER_CKSUM;
#elif defined(HAVE_KRB5_KEYUSAGE_APP_DATA_CKSUM) /* MIT */
	usage = KRB5_KEYUSAGE_APP_DATA_CKSUM;
#else
#error UNKNOWN_KRB5_KEYUSAGE
#endif

	ret = smb_krb5_verify_checksum(context,
				       keyblock,
				       usage,
				       &cksum,
				       pac_data.data,
				       pac_data.length);

	if (ret) {
		DEBUG(2,("check_pac_checksum: PAC Verification failed: %s (%d)\n",
			error_message(ret), ret));
		return ret;
	}

	return ret;
}

/****************************************************************
****************************************************************/

 NTSTATUS decode_pac_data(TALLOC_CTX *mem_ctx,
			 DATA_BLOB *pac_data_blob,
			 krb5_context context,
			 krb5_keyblock *service_keyblock,
			 krb5_const_principal client_principal,
			 time_t tgs_authtime,
			 struct PAC_DATA **pac_data_out)
{
	NTSTATUS status;
	enum ndr_err_code ndr_err;
	krb5_error_code ret;
	DATA_BLOB modified_pac_blob;

	NTTIME tgs_authtime_nttime;
	krb5_principal client_principal_pac = NULL;
	int i;

	struct PAC_SIGNATURE_DATA *srv_sig_ptr = NULL;
	struct PAC_SIGNATURE_DATA *kdc_sig_ptr = NULL;
	struct PAC_SIGNATURE_DATA *srv_sig_wipe = NULL;
	struct PAC_SIGNATURE_DATA *kdc_sig_wipe = NULL;
	struct PAC_LOGON_NAME *logon_name = NULL;
	struct PAC_LOGON_INFO *logon_info = NULL;
	struct PAC_DATA *pac_data = NULL;
	struct PAC_DATA_RAW *pac_data_raw = NULL;

	DATA_BLOB *srv_sig_blob = NULL;
	DATA_BLOB *kdc_sig_blob = NULL;

	*pac_data_out = NULL;

	pac_data = TALLOC_ZERO_P(mem_ctx, struct PAC_DATA);
	pac_data_raw = TALLOC_ZERO_P(mem_ctx, struct PAC_DATA_RAW);
	kdc_sig_wipe = TALLOC_ZERO_P(mem_ctx, struct PAC_SIGNATURE_DATA);
	srv_sig_wipe = TALLOC_ZERO_P(mem_ctx, struct PAC_SIGNATURE_DATA);
	if (!pac_data_raw || !pac_data || !kdc_sig_wipe || !srv_sig_wipe) {
		return NT_STATUS_NO_MEMORY;
	}

	ndr_err = ndr_pull_struct_blob(pac_data_blob, pac_data,
			NULL, pac_data,
		       (ndr_pull_flags_fn_t)ndr_pull_PAC_DATA);
	if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
		status = ndr_map_error2ntstatus(ndr_err);
		DEBUG(0,("can't parse the PAC: %s\n",
			nt_errstr(status)));
		return status;
	}

	if (pac_data->num_buffers < 4) {
		/* we need logon_ingo, service_key and kdc_key */
		DEBUG(0,("less than 4 PAC buffers\n"));
		return NT_STATUS_INVALID_PARAMETER;
	}

	ndr_err = ndr_pull_struct_blob(pac_data_blob, pac_data_raw,
				       NULL, pac_data_raw,
				       (ndr_pull_flags_fn_t)ndr_pull_PAC_DATA_RAW);
	if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
		status = ndr_map_error2ntstatus(ndr_err);
		DEBUG(0,("can't parse the PAC: %s\n",
			nt_errstr(status)));
		return status;
	}

	if (pac_data_raw->num_buffers < 4) {
		/* we need logon_ingo, service_key and kdc_key */
		DEBUG(0,("less than 4 PAC buffers\n"));
		return NT_STATUS_INVALID_PARAMETER;
	}

	if (pac_data->num_buffers != pac_data_raw->num_buffers) {
		/* we need logon_ingo, service_key and kdc_key */
		DEBUG(0,("misparse!  PAC_DATA has %d buffers while PAC_DATA_RAW has %d\n",
			 pac_data->num_buffers, pac_data_raw->num_buffers));
		return NT_STATUS_INVALID_PARAMETER;
	}

	for (i=0; i < pac_data->num_buffers; i++) {
		if (pac_data->buffers[i].type != pac_data_raw->buffers[i].type) {
			DEBUG(0,("misparse!  PAC_DATA buffer %d has type %d while PAC_DATA_RAW has %d\n",
				 i, pac_data->buffers[i].type, pac_data->buffers[i].type));
			return NT_STATUS_INVALID_PARAMETER;
		}
		switch (pac_data->buffers[i].type) {
			case PAC_TYPE_LOGON_INFO:
				if (!pac_data->buffers[i].info) {
					break;
				}
				logon_info = pac_data->buffers[i].info->logon_info.info;
				break;
			case PAC_TYPE_SRV_CHECKSUM:
				if (!pac_data->buffers[i].info) {
					break;
				}
				srv_sig_ptr = &pac_data->buffers[i].info->srv_cksum;
				srv_sig_blob = &pac_data_raw->buffers[i].info->remaining;
				break;
			case PAC_TYPE_KDC_CHECKSUM:
				if (!pac_data->buffers[i].info) {
					break;
				}
				kdc_sig_ptr = &pac_data->buffers[i].info->kdc_cksum;
				kdc_sig_blob = &pac_data_raw->buffers[i].info->remaining;
				break;
			case PAC_TYPE_LOGON_NAME:
				logon_name = &pac_data->buffers[i].info->logon_name;
				break;
			default:
				break;
		}
	}

	if (!logon_info) {
		DEBUG(0,("PAC no logon_info\n"));
		return NT_STATUS_INVALID_PARAMETER;
	}

	if (!logon_name) {
		DEBUG(0,("PAC no logon_name\n"));
		return NT_STATUS_INVALID_PARAMETER;
	}

	if (!srv_sig_ptr || !srv_sig_blob) {
		DEBUG(0,("PAC no srv_key\n"));
		return NT_STATUS_INVALID_PARAMETER;
	}

	if (!kdc_sig_ptr || !kdc_sig_blob) {
		DEBUG(0,("PAC no kdc_key\n"));
		return NT_STATUS_INVALID_PARAMETER;
	}

	/* Find and zero out the signatures, as required by the signing algorithm */

	/* We find the data blobs above, now we parse them to get at the exact portion we should zero */
	ndr_err = ndr_pull_struct_blob(kdc_sig_blob, kdc_sig_wipe,
				       NULL, kdc_sig_wipe,
				       (ndr_pull_flags_fn_t)ndr_pull_PAC_SIGNATURE_DATA);
	if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
		status = ndr_map_error2ntstatus(ndr_err);
		DEBUG(0,("can't parse the KDC signature: %s\n",
			nt_errstr(status)));
		return status;
	}

	ndr_err = ndr_pull_struct_blob(srv_sig_blob, srv_sig_wipe,
				       NULL, srv_sig_wipe,
				       (ndr_pull_flags_fn_t)ndr_pull_PAC_SIGNATURE_DATA);
	if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
		status = ndr_map_error2ntstatus(ndr_err);
		DEBUG(0,("can't parse the SRV signature: %s\n",
			nt_errstr(status)));
		return status;
	}

	/* Now zero the decoded structure */
	memset(kdc_sig_wipe->signature.data, '\0', kdc_sig_wipe->signature.length);
	memset(srv_sig_wipe->signature.data, '\0', srv_sig_wipe->signature.length);

	/* and reencode, back into the same place it came from */
	ndr_err = ndr_push_struct_blob(kdc_sig_blob, pac_data_raw,
				       NULL, kdc_sig_wipe,
				       (ndr_push_flags_fn_t)ndr_push_PAC_SIGNATURE_DATA);
	if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
		status = ndr_map_error2ntstatus(ndr_err);
		DEBUG(0,("can't repack the KDC signature: %s\n",
			nt_errstr(status)));
		return status;
	}
	ndr_err = ndr_push_struct_blob(srv_sig_blob, pac_data_raw,
				       NULL, srv_sig_wipe,
				       (ndr_push_flags_fn_t)ndr_push_PAC_SIGNATURE_DATA);
	if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
		status = ndr_map_error2ntstatus(ndr_err);
		DEBUG(0,("can't repack the SRV signature: %s\n",
			nt_errstr(status)));
		return status;
	}

	/* push out the whole structure, but now with zero'ed signatures */
	ndr_err = ndr_push_struct_blob(&modified_pac_blob, pac_data_raw,
				       NULL, pac_data_raw,
				       (ndr_push_flags_fn_t)ndr_push_PAC_DATA_RAW);
	if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
		status = ndr_map_error2ntstatus(ndr_err);
		DEBUG(0,("can't repack the RAW PAC: %s\n",
			nt_errstr(status)));
		return status;
	}

	/* verify by service_key */
	ret = check_pac_checksum(mem_ctx,
				 modified_pac_blob, srv_sig_ptr,
				 context,
				 service_keyblock);
	if (ret) {
		DEBUG(1, ("PAC Decode: Failed to verify the service signature: %s\n",
			  error_message(ret)));
		return NT_STATUS_ACCESS_DENIED;
	}

	/* Convert to NT time, so as not to loose accuracy in comparison */
	unix_to_nt_time(&tgs_authtime_nttime, tgs_authtime);

	if (tgs_authtime_nttime != logon_name->logon_time) {
		DEBUG(2, ("PAC Decode: Logon time mismatch between ticket and PAC!\n"));
		DEBUG(2, ("PAC Decode: PAC: %s\n", nt_time_string(mem_ctx, logon_name->logon_time)));
		DEBUG(2, ("PAC Decode: Ticket: %s\n", nt_time_string(mem_ctx, tgs_authtime_nttime)));
		return NT_STATUS_ACCESS_DENIED;
	}

	ret = smb_krb5_parse_name_norealm(context, logon_name->account_name,
				    &client_principal_pac);
	if (ret) {
		DEBUG(2, ("Could not parse name from incoming PAC: [%s]: %s\n",
			  logon_name->account_name,
			  error_message(ret)));
		return NT_STATUS_INVALID_PARAMETER;
	}

	if (!smb_krb5_principal_compare_any_realm(context, client_principal, client_principal_pac)) {
		DEBUG(2, ("Name in PAC [%s] does not match principal name in ticket\n",
			  logon_name->account_name));
		krb5_free_principal(context, client_principal_pac);
		return NT_STATUS_ACCESS_DENIED;
	}

	DEBUG(3,("Found account name from PAC: %s [%s]\n",
		 logon_info->info3.base.account_name.string,
		 logon_info->info3.base.full_name.string));

	DEBUG(10,("Successfully validated Kerberos PAC\n"));

	if (DEBUGLEVEL >= 10) {
		const char *s;
		s = NDR_PRINT_STRUCT_STRING(mem_ctx, PAC_DATA, pac_data);
		if (s) {
			DEBUGADD(10,("%s\n", s));
		}
	}

	*pac_data_out = pac_data;

	return NT_STATUS_OK;
}

/****************************************************************
****************************************************************/

struct PAC_LOGON_INFO *get_logon_info_from_pac(struct PAC_DATA *pac_data)
{
	int i;

	for (i=0; i < pac_data->num_buffers; i++) {

		if (pac_data->buffers[i].type != PAC_TYPE_LOGON_INFO) {
			continue;
		}

		return pac_data->buffers[i].info->logon_info.info;
	}

	return NULL;
}

/****************************************************************
****************************************************************/

NTSTATUS kerberos_return_pac(TALLOC_CTX *mem_ctx,
			     const char *name,
			     const char *pass,
			     time_t time_offset,
			     time_t *expire_time,
			     time_t *renew_till_time,
			     const char *cache_name,
			     bool request_pac,
			     bool add_netbios_addr,
			     time_t renewable_time,
			     const char *impersonate_princ_s,
			     struct PAC_DATA **pac_ret)
{
	krb5_error_code ret;
	NTSTATUS status = NT_STATUS_INVALID_PARAMETER;
	DATA_BLOB tkt, ap_rep, sesskey1, sesskey2;
	struct PAC_DATA *pac_data = NULL;
	char *client_princ_out = NULL;
	const char *auth_princ = NULL;
	const char *local_service = NULL;
	const char *cc = "MEMORY:kerberos_return_pac";

	ZERO_STRUCT(tkt);
	ZERO_STRUCT(ap_rep);
	ZERO_STRUCT(sesskey1);
	ZERO_STRUCT(sesskey2);

	if (!name || !pass) {
		return NT_STATUS_INVALID_PARAMETER;
	}

	if (cache_name) {
		cc = cache_name;
	}

	if (!strchr_m(name, '@')) {
		auth_princ = talloc_asprintf(mem_ctx, "%s@%s", name,
			lp_realm());
	} else {
		auth_princ = name;
	}
	NT_STATUS_HAVE_NO_MEMORY(auth_princ);

	local_service = talloc_asprintf(mem_ctx, "%s$@%s",
					global_myname(), lp_realm());
	NT_STATUS_HAVE_NO_MEMORY(local_service);

	ret = kerberos_kinit_password_ext(auth_princ,
					  pass,
					  time_offset,
					  expire_time,
					  renew_till_time,
					  cc,
					  request_pac,
					  add_netbios_addr,
					  renewable_time,
					  &status);
	if (ret) {
		DEBUG(1,("kinit failed for '%s' with: %s (%d)\n",
			auth_princ, error_message(ret), ret));
		/* status already set */
		goto out;
	}

	DEBUG(10,("got TGT for %s in %s\n", auth_princ, cc));
	if (expire_time) {
		DEBUGADD(10,("\tvalid until: %s (%d)\n",
			http_timestring(talloc_tos(), *expire_time),
			(int)*expire_time));
	}
	if (renew_till_time) {
		DEBUGADD(10,("\trenewable till: %s (%d)\n",
			http_timestring(talloc_tos(), *renew_till_time),
			(int)*renew_till_time));
	}

	/* we cannot continue with krb5 when UF_DONT_REQUIRE_PREAUTH is set,
	 * in that case fallback to NTLM - gd */

	if (expire_time && renew_till_time &&
	    (*expire_time == 0) && (*renew_till_time == 0)) {
		return NT_STATUS_INVALID_LOGON_TYPE;
	}

	ret = cli_krb5_get_ticket(local_service,
				  time_offset,
				  &tkt,
				  &sesskey1,
				  0,
				  cc,
				  NULL,
				  impersonate_princ_s);
	if (ret) {
		DEBUG(1,("failed to get ticket for %s: %s\n",
			local_service, error_message(ret)));
		if (impersonate_princ_s) {
			DEBUGADD(1,("tried S4U2SELF impersonation as: %s\n",
				impersonate_princ_s));
		}
		status = krb5_to_nt_status(ret);
		goto out;
	}
	status = ads_verify_ticket(mem_ctx,
				   lp_realm(),
				   time_offset,
				   &tkt,
				   &client_princ_out,
				   &pac_data,
				   &ap_rep,
				   &sesskey2,
				   False);
	if (!NT_STATUS_IS_OK(status)) {
		DEBUG(1,("ads_verify_ticket failed: %s\n",
			nt_errstr(status)));
		goto out;
	}

	if (!pac_data) {
		DEBUG(1,("no PAC\n"));
		status = NT_STATUS_INVALID_PARAMETER;
		goto out;
	}

	*pac_ret = pac_data;

out:
	if (cc != cache_name) {
		ads_kdestroy(cc);
	}

	data_blob_free(&tkt);
	data_blob_free(&ap_rep);
	data_blob_free(&sesskey1);
	data_blob_free(&sesskey2);

	TALLOC_FREE(client_princ_out);

	return status;
}

/****************************************************************
****************************************************************/

static NTSTATUS kerberos_return_pac_logon_info(TALLOC_CTX *mem_ctx,
					       const char *name,
					       const char *pass,
					       time_t time_offset,
					       time_t *expire_time,
					       time_t *renew_till_time,
					       const char *cache_name,
					       bool request_pac,
					       bool add_netbios_addr,
					       time_t renewable_time,
					       const char *impersonate_princ_s,
					       struct PAC_LOGON_INFO **logon_info)
{
	NTSTATUS status;
	struct PAC_DATA *pac_data = NULL;
	struct PAC_LOGON_INFO *info = NULL;

	status = kerberos_return_pac(mem_ctx,
				     name,
				     pass,
				     time_offset,
				     expire_time,
				     renew_till_time,
				     cache_name,
				     request_pac,
				     add_netbios_addr,
				     renewable_time,
				     impersonate_princ_s,
				     &pac_data);
	if (!NT_STATUS_IS_OK(status)) {
		return status;
	}

	if (!pac_data) {
		DEBUG(3,("no pac\n"));
		return NT_STATUS_INVALID_USER_BUFFER;
	}

	info = get_logon_info_from_pac(pac_data);
	if (!info) {
		DEBUG(1,("no logon_info\n"));
		return NT_STATUS_INVALID_USER_BUFFER;
	}

	*logon_info = info;

	return NT_STATUS_OK;
}

/****************************************************************
****************************************************************/

NTSTATUS kerberos_return_info3_from_pac(TALLOC_CTX *mem_ctx,
					const char *name,
					const char *pass,
					time_t time_offset,
					time_t *expire_time,
					time_t *renew_till_time,
					const char *cache_name,
					bool request_pac,
					bool add_netbios_addr,
					time_t renewable_time,
					const char *impersonate_princ_s,
					struct netr_SamInfo3 **info3)
{
	NTSTATUS status;
	struct PAC_LOGON_INFO *logon_info = NULL;

	status = kerberos_return_pac_logon_info(mem_ctx,
						name,
						pass,
						time_offset,
						expire_time,
						renew_till_time,
						cache_name,
						request_pac,
						add_netbios_addr,
						renewable_time,
						impersonate_princ_s,
						&logon_info);
	if (!NT_STATUS_IS_OK(status)) {
		return status;
	}

	*info3 = &logon_info->info3;

	return NT_STATUS_OK;
}
#endif