summaryrefslogtreecommitdiff
path: root/source4/auth/gensec/gensec_gssapi.c
blob: e6049edc5858ae14ed608b893589e7be0bca4658 (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
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
/* 
   Unix SMB/CIFS implementation.

   Kerberos backend for GENSEC
   
   Copyright (C) Andrew Bartlett <abartlet@samba.org> 2004-2005
   Copyright (C) Stefan Metzmacher <metze@samba.org> 2004-2005

   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 2 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, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

#include "includes.h"
#include "system/kerberos.h"
#include "system/network.h"
#include "auth/kerberos/kerberos.h"
#include "librpc/gen_ndr/ndr_krb5pac.h"
#include "auth/auth.h"

#undef DBGC_CLASS
#define DBGC_CLASS DBGC_AUTH

struct gensec_gssapi_state {
	gss_ctx_id_t gssapi_context;
	struct gss_channel_bindings_struct *input_chan_bindings;
	gss_name_t server_name;
	gss_name_t client_name;
	OM_uint32 want_flags, got_flags;
	const gss_OID_desc *gss_oid;

	DATA_BLOB session_key;
	DATA_BLOB pac;

	struct smb_krb5_context *smb_krb5_context;
	krb5_ccache ccache;
	const char *ccache_name;
	krb5_keytab keytab;

	gss_cred_id_t cred;
};

static char *gssapi_error_string(TALLOC_CTX *mem_ctx, 
				 OM_uint32 maj_stat, OM_uint32 min_stat)
{
	OM_uint32 disp_min_stat, disp_maj_stat;
	gss_buffer_desc maj_error_message;
	gss_buffer_desc min_error_message;
	OM_uint32 msg_ctx = 0;

	char *ret;

	maj_error_message.value = NULL;
	min_error_message.value = NULL;
	
	disp_maj_stat = gss_display_status(&disp_min_stat, maj_stat, GSS_C_GSS_CODE,
			   GSS_C_NULL_OID, &msg_ctx, &maj_error_message);
	disp_maj_stat = gss_display_status(&disp_min_stat, min_stat, GSS_C_MECH_CODE,
			   GSS_C_NULL_OID, &msg_ctx, &min_error_message);
	ret = talloc_asprintf(mem_ctx, "%s: %s", (char *)maj_error_message.value, (char *)min_error_message.value);

	gss_release_buffer(&disp_min_stat, &maj_error_message);
	gss_release_buffer(&disp_min_stat, &min_error_message);

	return ret;
}


static int gensec_gssapi_destory(void *ptr) 
{
	struct gensec_gssapi_state *gensec_gssapi_state = ptr;
	OM_uint32 maj_stat, min_stat;
	
	if (gensec_gssapi_state->cred != GSS_C_NO_CREDENTIAL) {
		maj_stat = gss_release_cred(&min_stat, 
					    &gensec_gssapi_state->cred);
	}

	if (gensec_gssapi_state->gssapi_context != GSS_C_NO_CONTEXT) {
		maj_stat = gss_delete_sec_context (&min_stat,
						   &gensec_gssapi_state->gssapi_context,
						   GSS_C_NO_BUFFER);
	}

	if (gensec_gssapi_state->server_name != GSS_C_NO_NAME) {
		maj_stat = gss_release_name(&min_stat, &gensec_gssapi_state->server_name);
	}
	if (gensec_gssapi_state->client_name != GSS_C_NO_NAME) {
		maj_stat = gss_release_name(&min_stat, &gensec_gssapi_state->client_name);
	}
	return 0;
}

static NTSTATUS gensec_gssapi_start(struct gensec_security *gensec_security)
{
	struct gensec_gssapi_state *gensec_gssapi_state;
	krb5_error_code ret;
	
	gensec_gssapi_state = talloc(gensec_security, struct gensec_gssapi_state);
	if (!gensec_gssapi_state) {
		return NT_STATUS_NO_MEMORY;
	}

	gensec_security->private_data = gensec_gssapi_state;

	gensec_gssapi_state->gssapi_context = GSS_C_NO_CONTEXT;
	gensec_gssapi_state->server_name = GSS_C_NO_NAME;
	gensec_gssapi_state->client_name = GSS_C_NO_NAME;

	/* TODO: Fill in channel bindings */
	gensec_gssapi_state->input_chan_bindings = GSS_C_NO_CHANNEL_BINDINGS;
	
	gensec_gssapi_state->want_flags = 0;
	gensec_gssapi_state->got_flags = 0;

	gensec_gssapi_state->session_key = data_blob(NULL, 0);
	gensec_gssapi_state->pac = data_blob(NULL, 0);

	gensec_gssapi_state->cred = GSS_C_NO_CREDENTIAL;

	talloc_set_destructor(gensec_gssapi_state, gensec_gssapi_destory); 

	if (gensec_security->want_features & GENSEC_FEATURE_SESSION_KEY) {
#ifndef HAVE_GSSKRB5_GET_INITIATOR_SUBKEY
		/* GSSAPI won't give us the session keys, without the
		 * right hooks.  This is critical when requested, so
		 * fail outright. */
		return NT_STATUS_INVALID_PARAMETER;
#endif
	}
	if (gensec_security->want_features & GENSEC_FEATURE_SIGN) {
		gensec_gssapi_state->want_flags |= GSS_C_INTEG_FLAG;
	}
	if (gensec_security->want_features & GENSEC_FEATURE_SEAL) {
		gensec_gssapi_state->want_flags |= GSS_C_CONF_FLAG;
	}
	if (gensec_security->want_features & GENSEC_FEATURE_DCE_STYLE) {
#ifndef GSS_C_DCE_STYLE
		/* GSSAPI DCE_STYLE is critical when requested, so
		 * fail outright */
		return NT_STATUS_INVALID_PARAMETER;
#else
		gensec_gssapi_state->want_flags |= GSS_C_DCE_STYLE;
#endif
	}

	gensec_gssapi_state->gss_oid = gss_mech_krb5;
	
	ret = smb_krb5_init_context(gensec_gssapi_state, 
				    &gensec_gssapi_state->smb_krb5_context);
	if (ret) {
		DEBUG(1,("gensec_krb5_start: krb5_init_context failed (%s)\n", 					
			 error_message(ret)));
		return NT_STATUS_INTERNAL_ERROR;
	}
	return NT_STATUS_OK;
}

static NTSTATUS gensec_gssapi_server_start(struct gensec_security *gensec_security)
{
	NTSTATUS nt_status;
	OM_uint32 maj_stat, min_stat;
	struct gensec_gssapi_state *gensec_gssapi_state;
	struct cli_credentials *machine_account;

	nt_status = gensec_gssapi_start(gensec_security);
	if (!NT_STATUS_IS_OK(nt_status)) {
		return nt_status;
	}

	gensec_gssapi_state = gensec_security->private_data;

	machine_account = cli_credentials_init(gensec_gssapi_state);
	cli_credentials_set_conf(machine_account);
	nt_status = cli_credentials_set_machine_account(machine_account);
	
	if (!NT_STATUS_IS_OK(nt_status)) {
		DEBUG(3, ("Could not obtain machine account credentials from the local database\n"));
		talloc_free(machine_account);
		return nt_status;
	} else {
		nt_status = create_memory_keytab(gensec_gssapi_state,
						 machine_account, 
						 gensec_gssapi_state->smb_krb5_context,
						 &gensec_gssapi_state->keytab);
		talloc_free(machine_account);
		if (!NT_STATUS_IS_OK(nt_status)) {
			DEBUG(3, ("Could not create memory keytab!\n"));
			talloc_free(machine_account);
			return nt_status;
		}
	}

	maj_stat = gsskrb5_acquire_cred(&min_stat, 
					gensec_gssapi_state->keytab, NULL,
					NULL,
					GSS_C_INDEFINITE,
					GSS_C_NULL_OID_SET,
					GSS_C_ACCEPT,
					&gensec_gssapi_state->cred,
					NULL, 
					NULL);
	if (maj_stat) {
		DEBUG(1, ("Aquiring acceptor credentails failed: %s\n", 
			  gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat)));
		return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
	}

	return NT_STATUS_OK;

}

static NTSTATUS gensec_gssapi_client_start(struct gensec_security *gensec_security)
{
	struct gensec_gssapi_state *gensec_gssapi_state;
	struct cli_credentials *creds = gensec_get_credentials(gensec_security);
	NTSTATUS nt_status;
	gss_buffer_desc name_token;
	OM_uint32 maj_stat, min_stat;
	const char *hostname = gensec_get_target_hostname(gensec_security);

	if (!hostname) {
		DEBUG(1, ("Could not determine hostname for target computer, cannot use kerberos\n"));
		return NT_STATUS_INVALID_PARAMETER;
	}
	if (is_ipaddress(hostname)) {
		DEBUG(2, ("Cannot do GSSAPI to a IP address"));
		return NT_STATUS_INVALID_PARAMETER;
	}

	nt_status = gensec_gssapi_start(gensec_security);
	if (!NT_STATUS_IS_OK(nt_status)) {
		return nt_status;
	}

	gensec_gssapi_state = gensec_security->private_data;

	name_token.value = talloc_asprintf(gensec_gssapi_state, "%s@%s", 
					   gensec_get_target_service(gensec_security), 
					   hostname);
	name_token.length = strlen(name_token.value);

	maj_stat = gss_import_name (&min_stat,
				    &name_token,
				    GSS_C_NT_HOSTBASED_SERVICE,
				    &gensec_gssapi_state->server_name);
	if (maj_stat) {
		DEBUG(1, ("GSS Import name of %s failed: %s\n",
			  (char *)name_token.value,
			  gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat)));
		return NT_STATUS_UNSUCCESSFUL;
	}

	name_token.value = cli_credentials_get_principal(creds, 
							 gensec_gssapi_state);
	name_token.length = strlen(name_token.value);

	maj_stat = gss_import_name (&min_stat,
				    &name_token,
				    GSS_C_NT_USER_NAME,
				    &gensec_gssapi_state->client_name);
	if (maj_stat) {
		DEBUG(1, ("GSS Import name of %s failed: %s\n",
			  (char *)name_token.value,
			  gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat)));
		return NT_STATUS_UNSUCCESSFUL;
	}

	nt_status = kinit_to_ccache(gensec_gssapi_state, 
				    creds,
				    gensec_gssapi_state->smb_krb5_context, 
				    &gensec_gssapi_state->ccache, &gensec_gssapi_state->ccache_name);
	if (!NT_STATUS_IS_OK(nt_status)) {
		return nt_status;
	}

	maj_stat = gsskrb5_acquire_cred(&min_stat, 
					NULL, gensec_gssapi_state->ccache,
					gensec_gssapi_state->client_name,
					GSS_C_INDEFINITE,
					GSS_C_NULL_OID_SET,
					GSS_C_INITIATE,
					&gensec_gssapi_state->cred,
					NULL, 
					NULL);
	if (maj_stat) {
		DEBUG(1, ("Aquiring initiator credentails failed: %s\n", 
			  gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat)));
		return NT_STATUS_UNSUCCESSFUL;
	}

	return NT_STATUS_OK;
}


/**
 * Check if the packet is one for this mechansim
 * 
 * @param gensec_security GENSEC state
 * @param in The request, as a DATA_BLOB
 * @return Error, INVALID_PARAMETER if it's not a packet for us
 *                or NT_STATUS_OK if the packet is ok. 
 */

static NTSTATUS gensec_gssapi_magic(struct gensec_security *gensec_security, 
				    const DATA_BLOB *in) 
{
	if (gensec_gssapi_check_oid(in, GENSEC_OID_KERBEROS5)) {
		return NT_STATUS_OK;
	} else {
		return NT_STATUS_INVALID_PARAMETER;
	}
}


/**
 * Next state function for the GSSAPI GENSEC mechanism
 * 
 * @param gensec_gssapi_state GSSAPI State
 * @param out_mem_ctx The TALLOC_CTX for *out to be allocated on
 * @param in The request, as a DATA_BLOB
 * @param out The reply, as an talloc()ed DATA_BLOB, on *out_mem_ctx
 * @return Error, MORE_PROCESSING_REQUIRED if a reply is sent, 
 *                or NT_STATUS_OK if the user is authenticated. 
 */

static NTSTATUS gensec_gssapi_update(struct gensec_security *gensec_security, 
				   TALLOC_CTX *out_mem_ctx, 
				   const DATA_BLOB in, DATA_BLOB *out) 
{
	struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
	NTSTATUS nt_status = NT_STATUS_UNSUCCESSFUL;
	OM_uint32 maj_stat, min_stat;
	OM_uint32 min_stat2;
	gss_buffer_desc input_token, output_token;
	gss_OID gss_oid_p;
	input_token.length = in.length;
	input_token.value = in.data;

	switch (gensec_security->gensec_role) {
	case GENSEC_CLIENT:
	{
		maj_stat = gss_init_sec_context(&min_stat, 
						gensec_gssapi_state->cred,
						&gensec_gssapi_state->gssapi_context, 
						gensec_gssapi_state->server_name, 
						discard_const_p(gss_OID_desc, gensec_gssapi_state->gss_oid),
						gensec_gssapi_state->want_flags, 
						0, 
						gensec_gssapi_state->input_chan_bindings,
						&input_token, 
						NULL, 
						&output_token, 
						&gensec_gssapi_state->got_flags, /* ret flags */
						NULL);
		break;
	}
	case GENSEC_SERVER:
	{
		maj_stat = gss_accept_sec_context(&min_stat, 
						  &gensec_gssapi_state->gssapi_context, 
						  gensec_gssapi_state->cred,
						  &input_token, 
						  gensec_gssapi_state->input_chan_bindings,
						  &gensec_gssapi_state->client_name, 
						  &gss_oid_p,
						  &output_token, 
						  &gensec_gssapi_state->got_flags, 
						  NULL, 
						  NULL);
		gensec_gssapi_state->gss_oid = gss_oid_p;
		break;
	}
	default:
		return NT_STATUS_INVALID_PARAMETER;
		
	}

	*out = data_blob_talloc(out_mem_ctx, output_token.value, output_token.length);
	gss_release_buffer(&min_stat2, &output_token);

	if (maj_stat == GSS_S_COMPLETE) {
		return NT_STATUS_OK;
	} else if (maj_stat == GSS_S_CONTINUE_NEEDED) {
		return NT_STATUS_MORE_PROCESSING_REQUIRED;
	} else {
		if (maj_stat == GSS_S_FAILURE
		    && (min_stat == KRB5KRB_AP_ERR_BADVERSION || min_stat == KRB5KRB_AP_ERR_MSG_TYPE)) {
			/* garbage input, possibly from the auto-mech detection */
			return NT_STATUS_INVALID_PARAMETER;
		}
		DEBUG(1, ("GSS Update failed: %s\n", 
			  gssapi_error_string(out_mem_ctx, maj_stat, min_stat)));
		return nt_status;
	}
}

static NTSTATUS gensec_gssapi_wrap(struct gensec_security *gensec_security, 
				   TALLOC_CTX *mem_ctx, 
				   const DATA_BLOB *in, 
				   DATA_BLOB *out)
{
	struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
	OM_uint32 maj_stat, min_stat;
	gss_buffer_desc input_token, output_token;
	int conf_state;
	input_token.length = in->length;
	input_token.value = in->data;
	
	maj_stat = gss_wrap(&min_stat, 
			    gensec_gssapi_state->gssapi_context, 
			    gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL),
			    GSS_C_QOP_DEFAULT,
			    &input_token,
			    &conf_state,
			    &output_token);
	if (GSS_ERROR(maj_stat)) {
		DEBUG(1, ("GSS Wrap failed: %s\n", 
			  gssapi_error_string(mem_ctx, maj_stat, min_stat)));
		return NT_STATUS_ACCESS_DENIED;
	}
	*out = data_blob_talloc(mem_ctx, output_token.value, output_token.length);

	gss_release_buffer(&min_stat, &output_token);

	if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
	    && !conf_state) {
		return NT_STATUS_ACCESS_DENIED;
	}
	return NT_STATUS_OK;
}

static NTSTATUS gensec_gssapi_unwrap(struct gensec_security *gensec_security, 
				     TALLOC_CTX *mem_ctx, 
				     const DATA_BLOB *in, 
				     DATA_BLOB *out)
{
	struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
	OM_uint32 maj_stat, min_stat;
	gss_buffer_desc input_token, output_token;
	int conf_state;
	gss_qop_t qop_state;
	input_token.length = in->length;
	input_token.value = in->data;
	
	maj_stat = gss_unwrap(&min_stat, 
			      gensec_gssapi_state->gssapi_context, 
			      &input_token,
			      &output_token, 
			      &conf_state,
			      &qop_state);
	if (GSS_ERROR(maj_stat)) {
		DEBUG(1, ("GSS UnWrap failed: %s\n", 
			  gssapi_error_string(mem_ctx, maj_stat, min_stat)));
		return NT_STATUS_ACCESS_DENIED;
	}
	*out = data_blob_talloc(mem_ctx, output_token.value, output_token.length);

	gss_release_buffer(&min_stat, &output_token);
	
	if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
	    && !conf_state) {
		return NT_STATUS_ACCESS_DENIED;
	}
	return NT_STATUS_OK;
}

static size_t gensec_gssapi_sig_size(struct gensec_security *gensec_security) 
{
	/* not const but work for DCERPC packets and arcfour */
	return 45;
}

static NTSTATUS gensec_gssapi_seal_packet(struct gensec_security *gensec_security, 
					  TALLOC_CTX *mem_ctx, 
					  uint8_t *data, size_t length, 
					  const uint8_t *whole_pdu, size_t pdu_length, 
					  DATA_BLOB *sig)
{
	struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
	OM_uint32 maj_stat, min_stat;
	gss_buffer_desc input_token, output_token;
	int conf_state;
	ssize_t sig_length = 0;

	input_token.length = length;
	input_token.value = data;
	
	maj_stat = gss_wrap(&min_stat, 
			    gensec_gssapi_state->gssapi_context,
			    gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL),
			    GSS_C_QOP_DEFAULT,
			    &input_token,
			    &conf_state,
			    &output_token);
	if (GSS_ERROR(maj_stat)) {
		DEBUG(1, ("GSS Wrap failed: %s\n", 
			  gssapi_error_string(mem_ctx, maj_stat, min_stat)));
		return NT_STATUS_ACCESS_DENIED;
	}

	if (output_token.length < length) {
		return NT_STATUS_INTERNAL_ERROR;
	}

	sig_length = 45;

	memcpy(data, ((uint8_t *)output_token.value) + sig_length, length);
	*sig = data_blob_talloc(mem_ctx, (uint8_t *)output_token.value, sig_length);

	dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);
	dump_data_pw("gensec_gssapi_seal_packet: clear\n", data, length);
	dump_data_pw("gensec_gssapi_seal_packet: sealed\n", ((uint8_t *)output_token.value) + sig_length, output_token.length - sig_length);

	gss_release_buffer(&min_stat, &output_token);

	if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
	    && !conf_state) {
		return NT_STATUS_ACCESS_DENIED;
	}
	return NT_STATUS_OK;
}

static NTSTATUS gensec_gssapi_unseal_packet(struct gensec_security *gensec_security, 
					    TALLOC_CTX *mem_ctx, 
					    uint8_t *data, size_t length, 
					    const uint8_t *whole_pdu, size_t pdu_length,
					    const DATA_BLOB *sig)
{
	struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
	OM_uint32 maj_stat, min_stat;
	gss_buffer_desc input_token, output_token;
	int conf_state;
	gss_qop_t qop_state;
	DATA_BLOB in;

	dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);

	in = data_blob_talloc(mem_ctx, NULL, sig->length + length);

	memcpy(in.data, sig->data, sig->length);
	memcpy(in.data + sig->length, data, length);

	input_token.length = in.length;
	input_token.value = in.data;
	
	maj_stat = gss_unwrap(&min_stat, 
			      gensec_gssapi_state->gssapi_context, 
			      &input_token,
			      &output_token, 
			      &conf_state,
			      &qop_state);
	if (GSS_ERROR(maj_stat)) {
		DEBUG(1, ("GSS UnWrap failed: %s\n", 
			  gssapi_error_string(mem_ctx, maj_stat, min_stat)));
		return NT_STATUS_ACCESS_DENIED;
	}

	if (output_token.length != length) {
		return NT_STATUS_INTERNAL_ERROR;
	}

	memcpy(data, output_token.value, length);

	gss_release_buffer(&min_stat, &output_token);
	
	if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
	    && !conf_state) {
		return NT_STATUS_ACCESS_DENIED;
	}
	return NT_STATUS_OK;
}

static NTSTATUS gensec_gssapi_sign_packet(struct gensec_security *gensec_security, 
					  TALLOC_CTX *mem_ctx, 
					  const uint8_t *data, size_t length, 
					  const uint8_t *whole_pdu, size_t pdu_length, 
					  DATA_BLOB *sig)
{
	struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
	OM_uint32 maj_stat, min_stat;
	gss_buffer_desc input_token, output_token;
	int conf_state;
	ssize_t sig_length = 0;

	input_token.length = length;
	input_token.value = discard_const_p(uint8_t *, data);

	maj_stat = gss_wrap(&min_stat, 
			    gensec_gssapi_state->gssapi_context,
			    0,
			    GSS_C_QOP_DEFAULT,
			    &input_token,
			    &conf_state,
			    &output_token);
	if (GSS_ERROR(maj_stat)) {
		DEBUG(1, ("GSS Wrap failed: %s\n", 
			  gssapi_error_string(mem_ctx, maj_stat, min_stat)));
		return NT_STATUS_ACCESS_DENIED;
	}

	if (output_token.length < length) {
		return NT_STATUS_INTERNAL_ERROR;
	}

	sig_length = 45;

	/*memcpy(data, ((uint8_t *)output_token.value) + sig_length, length);*/
	*sig = data_blob_talloc(mem_ctx, (uint8_t *)output_token.value, sig_length);

	dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);

	gss_release_buffer(&min_stat, &output_token);

	return NT_STATUS_OK;
}

static NTSTATUS gensec_gssapi_check_packet(struct gensec_security *gensec_security, 
					   TALLOC_CTX *mem_ctx, 
					   const uint8_t *data, size_t length, 
					   const uint8_t *whole_pdu, size_t pdu_length, 
					   const DATA_BLOB *sig)
{
	struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
	OM_uint32 maj_stat, min_stat;
	gss_buffer_desc input_token, output_token;
	int conf_state;
	gss_qop_t qop_state;
	DATA_BLOB in;

	dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);

	in = data_blob_talloc(mem_ctx, NULL, sig->length + length);

	memcpy(in.data, sig->data, sig->length);
	memcpy(in.data + sig->length, data, length);

	input_token.length = in.length;
	input_token.value = in.data;
	
	maj_stat = gss_unwrap(&min_stat, 
			      gensec_gssapi_state->gssapi_context, 
			      &input_token,
			      &output_token, 
			      &conf_state,
			      &qop_state);
	if (GSS_ERROR(maj_stat)) {
		DEBUG(1, ("GSS UnWrap failed: %s\n", 
			  gssapi_error_string(mem_ctx, maj_stat, min_stat)));
		return NT_STATUS_ACCESS_DENIED;
	}

	if (output_token.length != length) {
		return NT_STATUS_INTERNAL_ERROR;
	}

	gss_release_buffer(&min_stat, &output_token);

	return NT_STATUS_OK;
}

static BOOL gensec_gssapi_have_feature(struct gensec_security *gensec_security, 
				       uint32_t feature) 
{
	struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
	if (feature & GENSEC_FEATURE_SIGN) {
		return gensec_gssapi_state->got_flags & GSS_C_INTEG_FLAG;
	}
	if (feature & GENSEC_FEATURE_SEAL) {
		return gensec_gssapi_state->got_flags & GSS_C_CONF_FLAG;
	}
	if (feature & GENSEC_FEATURE_SESSION_KEY) {
#ifdef HAVE_GSSKRB5_GET_INITIATOR_SUBKEY
		if ((gensec_gssapi_state->gss_oid->length == gss_mech_krb5->length)
		    && (memcmp(gensec_gssapi_state->gss_oid->elements, gss_mech_krb5->elements, gensec_gssapi_state->gss_oid->length) == 0)) {
			return True;
		}
#endif 
	}
	return False;
}

static NTSTATUS gensec_gssapi_session_key(struct gensec_security *gensec_security, 
					  DATA_BLOB *session_key) 
{
	struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
	
	if (gensec_gssapi_state->session_key.data) {
		*session_key = gensec_gssapi_state->session_key;
		return NT_STATUS_OK;
	}

#ifdef HAVE_GSSKRB5_GET_INITIATOR_SUBKEY
	/* Ensure we only call this for GSSAPI/krb5, otherwise things could get very ugly */
	if ((gensec_gssapi_state->gss_oid->length == gss_mech_krb5->length)
	    && (memcmp(gensec_gssapi_state->gss_oid->elements, gss_mech_krb5->elements, 
		       gensec_gssapi_state->gss_oid->length) == 0)) {
		OM_uint32 maj_stat, min_stat;
		gss_buffer_desc skey;
		
		maj_stat = gsskrb5_get_initiator_subkey(&min_stat, 
							gensec_gssapi_state->gssapi_context, 
							&skey);
		
		if (maj_stat == 0) {
			DEBUG(10, ("Got KRB5 session key of length %d\n",  skey.length));
			gensec_gssapi_state->session_key = data_blob_talloc(gensec_gssapi_state, 
									    skey.value, skey.length);
			*session_key = gensec_gssapi_state->session_key;
			dump_data_pw("KRB5 Session Key:\n", session_key->data, session_key->length);
			
			gss_release_buffer(&min_stat, &skey);
			return NT_STATUS_OK;
		}
		return NT_STATUS_NO_USER_SESSION_KEY;
	}
#endif
	
	DEBUG(1, ("NO session key for this mech\n"));
	return NT_STATUS_NO_USER_SESSION_KEY;
}

static NTSTATUS gensec_gssapi_session_info(struct gensec_security *gensec_security,
					 struct auth_session_info **_session_info) 
{
	NTSTATUS nt_status;
	TALLOC_CTX *mem_ctx;
	struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
	struct auth_serversupplied_info *server_info = NULL;
	struct auth_session_info *session_info = NULL;
	struct PAC_LOGON_INFO *logon_info;
	char *p;
	char *principal;
	const char *account_name;
	const char *realm;
	OM_uint32 maj_stat, min_stat;
	gss_buffer_desc name_token;
	gss_buffer_desc pac;
	krb5_keyblock *keyblock;
	
	mem_ctx = talloc_named(gensec_gssapi_state, 0, "gensec_gssapi_session_info context"); 
	NT_STATUS_HAVE_NO_MEMORY(mem_ctx);

	maj_stat = gss_display_name (&min_stat,
				     gensec_gssapi_state->client_name,
				     &name_token,
				     NULL);
	if (maj_stat) {
		return NT_STATUS_FOOBAR;
	}

	principal = talloc_strndup(mem_ctx, name_token.value, name_token.length);

	gss_release_buffer(&min_stat, &name_token);

	if (!principal) {
		talloc_free(mem_ctx);
		return NT_STATUS_NO_MEMORY;
	}

	p = strchr(principal, '@');
	if (p) {
		*p = '\0';
		p++;
		realm = p;
	} else {
		realm = lp_realm();
	}
	account_name = principal;
	
	maj_stat = gss_krb5_copy_service_keyblock(&min_stat, 
						  gensec_gssapi_state->gssapi_context, 
						  &keyblock);

	maj_stat = gsskrb5_extract_authz_data_from_sec_context(&min_stat, 
							       gensec_gssapi_state->gssapi_context, 
							       KRB5_AUTHDATA_IF_RELEVANT,
							       &pac);
	
	if (maj_stat == 0) {
		DATA_BLOB pac_blob = data_blob_talloc(mem_ctx, pac.value, pac.length);
		pac_blob = unwrap_pac(mem_ctx, &pac_blob);
		gss_release_buffer(&min_stat, &pac);
		
		/* decode and verify the pac */
		nt_status = kerberos_decode_pac(mem_ctx, &logon_info, pac_blob,
						gensec_gssapi_state->smb_krb5_context,
						NULL, keyblock);

		if (NT_STATUS_IS_OK(nt_status)) {
			union netr_Validation validation;
			validation.sam3 = &logon_info->info3;
			nt_status = make_server_info_netlogon_validation(gensec_gssapi_state, 
									 account_name,
									 3, &validation,
									 &server_info); 
			if (!NT_STATUS_IS_OK(nt_status)) {
				talloc_free(mem_ctx);
				return nt_status;
			}
		} else {
			maj_stat = 1;
		}
	}
	
	if (maj_stat) {
		/* IF we have the PAC - otherwise we need to get this
		 * data from elsewere - local ldb, or (TODO) lookup of some
		 * kind... 
		 *
		 * when heimdal can generate the PAC, we should fail if there's
		 * no PAC present
		 */

		DATA_BLOB user_sess_key = data_blob(NULL, 0);
		DATA_BLOB lm_sess_key = data_blob(NULL, 0);
		/* TODO: should we pass the krb5 session key in here? */
		nt_status = sam_get_server_info(mem_ctx, account_name, realm,
						user_sess_key, lm_sess_key,
						&server_info);
		if (!NT_STATUS_IS_OK(nt_status)) {
			talloc_free(mem_ctx);
			return nt_status;
		}
	}

	/* references the server_info into the session_info */
	nt_status = auth_generate_session_info(gensec_gssapi_state, server_info, &session_info);
	talloc_free(server_info);
	NT_STATUS_NOT_OK_RETURN(nt_status);

	nt_status = gensec_gssapi_session_key(gensec_security, &session_info->session_key);
	NT_STATUS_NOT_OK_RETURN(nt_status);

	*_session_info = session_info;

	return NT_STATUS_OK;
}

static const char *gensec_krb5_oids[] = { 
	GENSEC_OID_KERBEROS5,
	GENSEC_OID_KERBEROS5_OLD,
	NULL 
};

/* As a server, this could in theory accept any GSSAPI mech */
static const struct gensec_security_ops gensec_gssapi_krb5_security_ops = {
	.name		= "gssapi_krb5",
	.oid            = gensec_krb5_oids,
	.client_start   = gensec_gssapi_client_start,
	.server_start   = gensec_gssapi_server_start,
	.magic  	= gensec_gssapi_magic,
	.update 	= gensec_gssapi_update,
	.session_key	= gensec_gssapi_session_key,
	.session_info	= gensec_gssapi_session_info,
	.sig_size	= gensec_gssapi_sig_size,
	.sign_packet	= gensec_gssapi_sign_packet,
	.check_packet	= gensec_gssapi_check_packet,
	.seal_packet	= gensec_gssapi_seal_packet,
	.unseal_packet	= gensec_gssapi_unseal_packet,
	.wrap           = gensec_gssapi_wrap,
	.unwrap         = gensec_gssapi_unwrap,
	.have_feature   = gensec_gssapi_have_feature,
	.enabled        = False
};

NTSTATUS gensec_gssapi_init(void)
{
	NTSTATUS ret;

	ret = gensec_register(&gensec_gssapi_krb5_security_ops);
	if (!NT_STATUS_IS_OK(ret)) {
		DEBUG(0,("Failed to register '%s' gensec backend!\n",
			gensec_gssapi_krb5_security_ops.name));
		return ret;
	}

	return ret;
}