summaryrefslogtreecommitdiff
path: root/source4/auth/gensec/gensec.c
blob: b166d238de2e19dc8ae9b3d3e8ecb5f41863ae73 (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
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
/* 
   Unix SMB/CIFS implementation.
 
   Generic Authentication Interface

   Copyright (C) Andrew Tridgell 2003
   Copyright (C) Andrew Bartlett <abartlet@samba.org> 2004-2006
   
   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 "system/network.h"
#include "lib/events/events.h"
#include "lib/socket/socket.h"
#include "lib/tsocket/tsocket.h"
#include "../lib/util/tevent_ntstatus.h"
#include "librpc/rpc/dcerpc.h"
#include "auth/credentials/credentials.h"
#include "auth/gensec/gensec.h"
#include "auth/auth.h"
#include "auth/system_session_proto.h"
#include "param/param.h"
#include "lib/util/tsort.h"

/* the list of currently registered GENSEC backends */
static struct gensec_security_ops **generic_security_ops;
static int gensec_num_backends;

/* Return all the registered mechs.  Don't modify the return pointer,
 * but you may talloc_reference it if convient */
_PUBLIC_ struct gensec_security_ops **gensec_security_all(void)
{
	return generic_security_ops;
}

bool gensec_security_ops_enabled(struct gensec_security_ops *ops, struct gensec_security *security)
{
	return lp_parm_bool(security->settings->lp_ctx, NULL, "gensec", ops->name, ops->enabled);
}

/* Sometimes we want to force only kerberos, sometimes we want to
 * force it's avoidance.  The old list could be either
 * gensec_security_all(), or from cli_credentials_gensec_list() (ie,
 * an existing list we have trimmed down) */

_PUBLIC_ struct gensec_security_ops **gensec_use_kerberos_mechs(TALLOC_CTX *mem_ctx, 
						       struct gensec_security_ops **old_gensec_list, 
						       struct cli_credentials *creds)
{
	struct gensec_security_ops **new_gensec_list;
	int i, j, num_mechs_in;
	enum credentials_use_kerberos use_kerberos = CRED_AUTO_USE_KERBEROS;

	if (creds) {
		use_kerberos = cli_credentials_get_kerberos_state(creds);
	}

	if (use_kerberos == CRED_AUTO_USE_KERBEROS) {
		if (!talloc_reference(mem_ctx, old_gensec_list)) {
			return NULL;
		}
		return old_gensec_list;
	}

	for (num_mechs_in=0; old_gensec_list && old_gensec_list[num_mechs_in]; num_mechs_in++) {
		/* noop */
	}

	new_gensec_list = talloc_array(mem_ctx, struct gensec_security_ops *, num_mechs_in + 1);
	if (!new_gensec_list) {
		return NULL;
	}

	j = 0;
	for (i=0; old_gensec_list && old_gensec_list[i]; i++) {
		int oid_idx;

		for (oid_idx = 0; old_gensec_list[i]->oid && old_gensec_list[i]->oid[oid_idx]; oid_idx++) {
			if (strcmp(old_gensec_list[i]->oid[oid_idx], GENSEC_OID_SPNEGO) == 0) {
				new_gensec_list[j] = old_gensec_list[i];
				j++;
				break;
			}
		}
		switch (use_kerberos) {
		case CRED_DONT_USE_KERBEROS:
			if (old_gensec_list[i]->kerberos == false) {
				new_gensec_list[j] = old_gensec_list[i];
				j++;
			}
			break;
		case CRED_MUST_USE_KERBEROS:
			if (old_gensec_list[i]->kerberos == true) {
				new_gensec_list[j] = old_gensec_list[i];
				j++;
			}
			break;
		default:
			/* Can't happen or invalid parameter */
			return NULL;
		}
	}
	new_gensec_list[j] = NULL; 
	
	return new_gensec_list;
}

struct gensec_security_ops **gensec_security_mechs(struct gensec_security *gensec_security,
						   TALLOC_CTX *mem_ctx) 
{
	struct gensec_security_ops **backends;
	backends = gensec_security_all();
	if (!gensec_security) {
		if (!talloc_reference(mem_ctx, backends)) {
			return NULL;
		}
		return backends;
	} else {
		struct cli_credentials *creds = gensec_get_credentials(gensec_security);
		if (!creds) {
			if (!talloc_reference(mem_ctx, backends)) {
				return NULL;
			}
			return backends;
		}
		return gensec_use_kerberos_mechs(mem_ctx, backends, creds);
	}
}

static const struct gensec_security_ops *gensec_security_by_authtype(struct gensec_security *gensec_security,
								     uint8_t auth_type)
{
	int i;
	struct gensec_security_ops **backends;
	const struct gensec_security_ops *backend;
	TALLOC_CTX *mem_ctx = talloc_new(gensec_security);
	if (!mem_ctx) {
		return NULL;
	}
	backends = gensec_security_mechs(gensec_security, mem_ctx);
	for (i=0; backends && backends[i]; i++) {
	    	if (!gensec_security_ops_enabled(backends[i], gensec_security))
				continue;
		if (backends[i]->auth_type == auth_type) {
			backend = backends[i];
			talloc_free(mem_ctx);
			return backend;
		}
	}
	talloc_free(mem_ctx);

	return NULL;
}

const struct gensec_security_ops *gensec_security_by_oid(struct gensec_security *gensec_security,
							 const char *oid_string)
{
	int i, j;
	struct gensec_security_ops **backends;
	const struct gensec_security_ops *backend;
	TALLOC_CTX *mem_ctx = talloc_new(gensec_security);
	if (!mem_ctx) {
		return NULL;
	}
	backends = gensec_security_mechs(gensec_security, mem_ctx);
	for (i=0; backends && backends[i]; i++) {
	    	if (gensec_security != NULL && 
				!gensec_security_ops_enabled(backends[i], 
											 gensec_security))
		    continue;
		if (backends[i]->oid) {
			for (j=0; backends[i]->oid[j]; j++) { 
				if (backends[i]->oid[j] &&
				    (strcmp(backends[i]->oid[j], oid_string) == 0)) {
					backend = backends[i];
					talloc_free(mem_ctx);
					return backend;
				}
			}
		}
	}
	talloc_free(mem_ctx);

	return NULL;
}

const struct gensec_security_ops *gensec_security_by_sasl_name(struct gensec_security *gensec_security,
							       const char *sasl_name)
{
	int i;
	struct gensec_security_ops **backends;
	const struct gensec_security_ops *backend;
	TALLOC_CTX *mem_ctx = talloc_new(gensec_security);
	if (!mem_ctx) {
		return NULL;
	}
	backends = gensec_security_mechs(gensec_security, mem_ctx);
	for (i=0; backends && backends[i]; i++) {
	    	if (!gensec_security_ops_enabled(backends[i], gensec_security))
		    continue;
		if (backends[i]->sasl_name 
		    && (strcmp(backends[i]->sasl_name, sasl_name) == 0)) {
			backend = backends[i];
			talloc_free(mem_ctx);
			return backend;
		}
	}
	talloc_free(mem_ctx);

	return NULL;
}

static const struct gensec_security_ops *gensec_security_by_name(struct gensec_security *gensec_security,
								 const char *name)
{
	int i;
	struct gensec_security_ops **backends;
	const struct gensec_security_ops *backend;
	TALLOC_CTX *mem_ctx = talloc_new(gensec_security);
	if (!mem_ctx) {
		return NULL;
	}
	backends = gensec_security_mechs(gensec_security, mem_ctx);
	for (i=0; backends && backends[i]; i++) {
	    	if (gensec_security != NULL && 
				!gensec_security_ops_enabled(backends[i], gensec_security))
		    continue;
		if (backends[i]->name 
		    && (strcmp(backends[i]->name, name) == 0)) {
			backend = backends[i];
			talloc_free(mem_ctx);
			return backend;
		}
	}
	talloc_free(mem_ctx);
	return NULL;
}

/**
 * Return a unique list of security subsystems from those specified in
 * the list of SASL names.   
 *
 * Use the list of enabled GENSEC mechanisms from the credentials
 * attached to the gensec_security, and return in our preferred order.
 */

const struct gensec_security_ops **gensec_security_by_sasl_list(struct gensec_security *gensec_security,
								TALLOC_CTX *mem_ctx, 
								const char **sasl_names)
{
	const struct gensec_security_ops **backends_out;
	struct gensec_security_ops **backends;
	int i, k, sasl_idx;
	int num_backends_out = 0;

	if (!sasl_names) {
		return NULL;
	}

	backends = gensec_security_mechs(gensec_security, mem_ctx);

	backends_out = talloc_array(mem_ctx, const struct gensec_security_ops *, 1);
	if (!backends_out) {
		return NULL;
	}
	backends_out[0] = NULL;

	/* Find backends in our preferred order, by walking our list,
	 * then looking in the supplied list */
	for (i=0; backends && backends[i]; i++) {
	    	if (gensec_security != NULL &&
				!gensec_security_ops_enabled(backends[i], gensec_security))
		    continue;
		for (sasl_idx = 0; sasl_names[sasl_idx]; sasl_idx++) {
			if (!backends[i]->sasl_name ||
			    !(strcmp(backends[i]->sasl_name, 
				     sasl_names[sasl_idx]) == 0)) {
				continue;
			}
			
			for (k=0; backends_out[k]; k++) {
				if (backends_out[k] == backends[i]) {
					break;
				}
			}
			
			if (k < num_backends_out) {
				/* already in there */
				continue;
			}
			
			backends_out = talloc_realloc(mem_ctx, backends_out, 
						      const struct gensec_security_ops *, 
						      num_backends_out + 2);
			if (!backends_out) {
				return NULL;
			}
			
			backends_out[num_backends_out] = backends[i];
			num_backends_out++;
			backends_out[num_backends_out] = NULL;
		}
	}
	return backends_out;
}

/**
 * Return a unique list of security subsystems from those specified in
 * the OID list.  That is, where two OIDs refer to the same module,
 * return that module only once. 
 *
 * Use the list of enabled GENSEC mechanisms from the credentials
 * attached to the gensec_security, and return in our preferred order.
 */

const struct gensec_security_ops_wrapper *gensec_security_by_oid_list(struct gensec_security *gensec_security,
								      TALLOC_CTX *mem_ctx, 
								      const char **oid_strings,
								      const char *skip)
{
	struct gensec_security_ops_wrapper *backends_out;
	struct gensec_security_ops **backends;
	int i, j, k, oid_idx;
	int num_backends_out = 0;

	if (!oid_strings) {
		return NULL;
	}

	backends = gensec_security_mechs(gensec_security, gensec_security);

	backends_out = talloc_array(mem_ctx, struct gensec_security_ops_wrapper, 1);
	if (!backends_out) {
		return NULL;
	}
	backends_out[0].op = NULL;
	backends_out[0].oid = NULL;

	/* Find backends in our preferred order, by walking our list,
	 * then looking in the supplied list */
	for (i=0; backends && backends[i]; i++) {
	    	if (gensec_security != NULL && 
				!gensec_security_ops_enabled(backends[i], gensec_security))
		    continue;
		if (!backends[i]->oid) {
			continue;
		}
		for (oid_idx = 0; oid_strings[oid_idx]; oid_idx++) {
			if (strcmp(oid_strings[oid_idx], skip) == 0) {
				continue;
			}

			for (j=0; backends[i]->oid[j]; j++) { 
				if (!backends[i]->oid[j] ||
				    !(strcmp(backends[i]->oid[j], 
					    oid_strings[oid_idx]) == 0)) {
					continue;
				}
				
				for (k=0; backends_out[k].op; k++) {
					if (backends_out[k].op == backends[i]) {
						break;
					}
				}
				
				if (k < num_backends_out) {
					/* already in there */
					continue;
				}

				backends_out = talloc_realloc(mem_ctx, backends_out, 
							      struct gensec_security_ops_wrapper, 
							      num_backends_out + 2);
				if (!backends_out) {
					return NULL;
				}
				
				backends_out[num_backends_out].op = backends[i];
				backends_out[num_backends_out].oid = backends[i]->oid[j];
				num_backends_out++;
				backends_out[num_backends_out].op = NULL;
				backends_out[num_backends_out].oid = NULL;
			}
		}
	}
	return backends_out;
}

/**
 * Return OIDS from the security subsystems listed
 */

const char **gensec_security_oids_from_ops(struct gensec_security *gensec_security,
										   TALLOC_CTX *mem_ctx, 
					   struct gensec_security_ops **ops,				   
					   const char *skip) 
{
	int i;
	int j = 0;
	int k;
	const char **oid_list;
	if (!ops) {
		return NULL;
	}
	oid_list = talloc_array(mem_ctx, const char *, 1);
	if (!oid_list) {
		return NULL;
	}
	
	for (i=0; ops && ops[i]; i++) {
		if (gensec_security != NULL && 
			!gensec_security_ops_enabled(ops[i], gensec_security)) {
			continue;
		}
		if (!ops[i]->oid) {
			continue;
		}
		
		for (k = 0; ops[i]->oid[k]; k++) {
			if (skip && strcmp(skip, ops[i]->oid[k])==0) {
			} else {
				oid_list = talloc_realloc(mem_ctx, oid_list, const char *, j + 2);
				if (!oid_list) {
					return NULL;
				}
				oid_list[j] = ops[i]->oid[k];
				j++;
			}
		}
	}
	oid_list[j] = NULL;
	return oid_list;
}


/**
 * Return OIDS from the security subsystems listed
 */

const char **gensec_security_oids_from_ops_wrapped(TALLOC_CTX *mem_ctx, 
						   const struct gensec_security_ops_wrapper *wops)
{
	int i;
	int j = 0;
	int k;
	const char **oid_list;
	if (!wops) {
		return NULL;
	}
	oid_list = talloc_array(mem_ctx, const char *, 1);
	if (!oid_list) {
		return NULL;
	}
	
	for (i=0; wops[i].op; i++) {
		if (!wops[i].op->oid) {
			continue;
		}
		
		for (k = 0; wops[i].op->oid[k]; k++) {
			oid_list = talloc_realloc(mem_ctx, oid_list, const char *, j + 2);
			if (!oid_list) {
				return NULL;
			}
			oid_list[j] = wops[i].op->oid[k];
			j++;
		}
	}
	oid_list[j] = NULL;
	return oid_list;
}


/**
 * Return all the security subsystems currently enabled on a GENSEC context.
 * 
 * This is taken from a list attached to the cli_credentials, and
 * skips the OID in 'skip'.  (Typically the SPNEGO OID)
 * 
 */

const char **gensec_security_oids(struct gensec_security *gensec_security, 
				  TALLOC_CTX *mem_ctx, 
				  const char *skip) 
{
	struct gensec_security_ops **ops
		= gensec_security_mechs(gensec_security, mem_ctx);
	return gensec_security_oids_from_ops(gensec_security, mem_ctx, ops, skip);
}



/**
  Start the GENSEC system, returning a context pointer.
  @param mem_ctx The parent TALLOC memory context.
  @param gensec_security Returned GENSEC context pointer.
  @note  The mem_ctx is only a parent and may be NULL.
  @note, the auth context is moved to be a child of the
  @ gensec_security return 
*/
static NTSTATUS gensec_start(TALLOC_CTX *mem_ctx, 
			     struct tevent_context *ev,
			     struct gensec_settings *settings,
 			     struct auth_context *auth_context,
			     struct gensec_security **gensec_security)
{
	if (ev == NULL) {
		DEBUG(0, ("No event context available!\n"));
		return NT_STATUS_INTERNAL_ERROR;
	}

	(*gensec_security) = talloc(mem_ctx, struct gensec_security);
	NT_STATUS_HAVE_NO_MEMORY(*gensec_security);

	(*gensec_security)->ops = NULL;
	(*gensec_security)->local_addr = NULL;
	(*gensec_security)->remote_addr = NULL;
	(*gensec_security)->private_data = NULL;

	ZERO_STRUCT((*gensec_security)->target);

	(*gensec_security)->subcontext = false;
	(*gensec_security)->want_features = 0;

	(*gensec_security)->event_ctx = ev;
	SMB_ASSERT(settings->lp_ctx != NULL);
	(*gensec_security)->settings = talloc_reference(*gensec_security, settings);
	(*gensec_security)->auth_context = talloc_steal(*gensec_security, auth_context);

	return NT_STATUS_OK;
}

/** 
 * Start a GENSEC subcontext, with a copy of the properties of the parent
 * @param mem_ctx The parent TALLOC memory context.
 * @param parent The parent GENSEC context 
 * @param gensec_security Returned GENSEC context pointer.
 * @note Used by SPNEGO in particular, for the actual implementation mechanism
 */

_PUBLIC_ NTSTATUS gensec_subcontext_start(TALLOC_CTX *mem_ctx, 
				 struct gensec_security *parent, 
				 struct gensec_security **gensec_security)
{
	(*gensec_security) = talloc(mem_ctx, struct gensec_security);
	NT_STATUS_HAVE_NO_MEMORY(*gensec_security);

	(**gensec_security) = *parent;
	(*gensec_security)->ops = NULL;
	(*gensec_security)->private_data = NULL;

	(*gensec_security)->subcontext = true;
	(*gensec_security)->want_features = parent->want_features;
	(*gensec_security)->event_ctx = parent->event_ctx;
	(*gensec_security)->auth_context = talloc_reference(*gensec_security, parent->auth_context);
	(*gensec_security)->settings = talloc_reference(*gensec_security, parent->settings);
	(*gensec_security)->auth_context = talloc_reference(*gensec_security, parent->auth_context);

	return NT_STATUS_OK;
}

/**
  Start the GENSEC system, in client mode, returning a context pointer.
  @param mem_ctx The parent TALLOC memory context.
  @param gensec_security Returned GENSEC context pointer.
  @note  The mem_ctx is only a parent and may be NULL.
*/
_PUBLIC_ NTSTATUS gensec_client_start(TALLOC_CTX *mem_ctx, 
			     struct gensec_security **gensec_security,
			     struct tevent_context *ev,
			     struct gensec_settings *settings)
{
	NTSTATUS status;

	if (settings == NULL) {
		DEBUG(0,("gensec_client_start: no settings given!\n"));
		return NT_STATUS_INTERNAL_ERROR;
	}

	status = gensec_start(mem_ctx, ev, settings, NULL, gensec_security);
	if (!NT_STATUS_IS_OK(status)) {
		return status;
	}
	(*gensec_security)->gensec_role = GENSEC_CLIENT;

	return status;
}



/**
  Start the GENSEC system, in server mode, returning a context pointer.
  @param mem_ctx The parent TALLOC memory context.
  @param gensec_security Returned GENSEC context pointer.
  @note  The mem_ctx is only a parent and may be NULL.
*/
_PUBLIC_ NTSTATUS gensec_server_start(TALLOC_CTX *mem_ctx, 
				      struct tevent_context *ev,
				      struct gensec_settings *settings,
				      struct auth_context *auth_context,
				      struct gensec_security **gensec_security)
{
	NTSTATUS status;

	if (!ev) {
		DEBUG(0,("gensec_server_start: no event context given!\n"));
		return NT_STATUS_INTERNAL_ERROR;
	}

	if (!settings) {
		DEBUG(0,("gensec_server_start: no settings given!\n"));
		return NT_STATUS_INTERNAL_ERROR;
	}

	status = gensec_start(mem_ctx, ev, settings, auth_context, gensec_security);
	if (!NT_STATUS_IS_OK(status)) {
		return status;
	}
	(*gensec_security)->gensec_role = GENSEC_SERVER;

	return status;
}

static NTSTATUS gensec_start_mech(struct gensec_security *gensec_security) 
{
	NTSTATUS status;
	DEBUG(5, ("Starting GENSEC %smechanism %s\n", 
		  gensec_security->subcontext ? "sub" : "", 
		  gensec_security->ops->name));
	switch (gensec_security->gensec_role) {
	case GENSEC_CLIENT:
		if (gensec_security->ops->client_start) {
			status = gensec_security->ops->client_start(gensec_security);
			if (!NT_STATUS_IS_OK(status)) {
				DEBUG(2, ("Failed to start GENSEC client mech %s: %s\n",
					  gensec_security->ops->name, nt_errstr(status))); 
			}
			return status;
		}
		break;
	case GENSEC_SERVER:
		if (gensec_security->ops->server_start) {
			status = gensec_security->ops->server_start(gensec_security);
			if (!NT_STATUS_IS_OK(status)) {
				DEBUG(1, ("Failed to start GENSEC server mech %s: %s\n",
					  gensec_security->ops->name, nt_errstr(status))); 
			}
			return status;
		}
		break;
	}
	return NT_STATUS_INVALID_PARAMETER;
}

/** 
 * Start a GENSEC sub-mechanism by DCERPC allocated 'auth type' number 
 * @param gensec_security GENSEC context pointer.
 * @param auth_type DCERPC auth type
 * @param auth_level DCERPC auth level 
 */

_PUBLIC_ NTSTATUS gensec_start_mech_by_authtype(struct gensec_security *gensec_security, 
				       uint8_t auth_type, uint8_t auth_level) 
{
	gensec_security->ops = gensec_security_by_authtype(gensec_security, auth_type);
	if (!gensec_security->ops) {
		DEBUG(3, ("Could not find GENSEC backend for auth_type=%d\n", (int)auth_type));
		return NT_STATUS_INVALID_PARAMETER;
	}
	gensec_want_feature(gensec_security, GENSEC_FEATURE_DCE_STYLE);
	gensec_want_feature(gensec_security, GENSEC_FEATURE_ASYNC_REPLIES);
	if (auth_level == DCERPC_AUTH_LEVEL_INTEGRITY) {
		gensec_want_feature(gensec_security, GENSEC_FEATURE_SIGN);
	} else if (auth_level == DCERPC_AUTH_LEVEL_PRIVACY) {
		gensec_want_feature(gensec_security, GENSEC_FEATURE_SIGN);
		gensec_want_feature(gensec_security, GENSEC_FEATURE_SEAL);
	} else if (auth_level == DCERPC_AUTH_LEVEL_CONNECT) {
		/* Default features */
	} else {
		DEBUG(2,("auth_level %d not supported in DCE/RPC authentication\n", 
			 auth_level));
		return NT_STATUS_INVALID_PARAMETER;
	}

	return gensec_start_mech(gensec_security);
}

_PUBLIC_ const char *gensec_get_name_by_authtype(struct gensec_security *gensec_security, uint8_t authtype) 
{
	const struct gensec_security_ops *ops;
	ops = gensec_security_by_authtype(gensec_security, authtype);
	if (ops) {
		return ops->name;
	}
	return NULL;
}
	

_PUBLIC_ const char *gensec_get_name_by_oid(struct gensec_security *gensec_security,
											const char *oid_string) 
{
	const struct gensec_security_ops *ops;
	ops = gensec_security_by_oid(gensec_security, oid_string);
	if (ops) {
		return ops->name;
	}
	return oid_string;
}
	

/** 
 * Start a GENSEC sub-mechanism with a specifed mechansim structure, used in SPNEGO
 *
 */

NTSTATUS gensec_start_mech_by_ops(struct gensec_security *gensec_security, 
				  const struct gensec_security_ops *ops) 
{
	gensec_security->ops = ops;
	return gensec_start_mech(gensec_security);
}

/** 
 * Start a GENSEC sub-mechanism by OID, used in SPNEGO
 *
 * @note This should also be used when you wish to just start NLTMSSP (for example), as it uses a
 *       well-known #define to hook it in.
 */

_PUBLIC_ NTSTATUS gensec_start_mech_by_oid(struct gensec_security *gensec_security, 
				  const char *mech_oid) 
{
	SMB_ASSERT(gensec_security != NULL);

	gensec_security->ops = gensec_security_by_oid(gensec_security, mech_oid);
	if (!gensec_security->ops) {
		DEBUG(3, ("Could not find GENSEC backend for oid=%s\n", mech_oid));
		return NT_STATUS_INVALID_PARAMETER;
	}
	return gensec_start_mech(gensec_security);
}

/** 
 * Start a GENSEC sub-mechanism by a well know SASL name
 *
 */

_PUBLIC_ NTSTATUS gensec_start_mech_by_sasl_name(struct gensec_security *gensec_security, 
					const char *sasl_name) 
{
	gensec_security->ops = gensec_security_by_sasl_name(gensec_security, sasl_name);
	if (!gensec_security->ops) {
		DEBUG(3, ("Could not find GENSEC backend for sasl_name=%s\n", sasl_name));
		return NT_STATUS_INVALID_PARAMETER;
	}
	return gensec_start_mech(gensec_security);
}

/** 
 * Start a GENSEC sub-mechanism with the preferred option from a SASL name list
 *
 */

_PUBLIC_ NTSTATUS gensec_start_mech_by_sasl_list(struct gensec_security *gensec_security, 
						 const char **sasl_names) 
{
	NTSTATUS nt_status = NT_STATUS_INVALID_PARAMETER;
	TALLOC_CTX *mem_ctx = talloc_new(gensec_security);
	const struct gensec_security_ops **ops;
	int i;
	if (!mem_ctx) {
		return NT_STATUS_NO_MEMORY;
	}
	ops = gensec_security_by_sasl_list(gensec_security, mem_ctx, sasl_names);
	if (!ops || !*ops) {
		DEBUG(3, ("Could not find GENSEC backend for any of sasl_name = %s\n", 
			  str_list_join(mem_ctx, 
					sasl_names, ' ')));
		talloc_free(mem_ctx);
		return NT_STATUS_INVALID_PARAMETER;
	}
	for (i=0; ops[i]; i++) {
		nt_status = gensec_start_mech_by_ops(gensec_security, ops[i]);
		if (!NT_STATUS_EQUAL(nt_status, NT_STATUS_INVALID_PARAMETER)) {
			break;
		}
	}
	talloc_free(mem_ctx);
	return nt_status;
}

/** 
 * Start a GENSEC sub-mechanism by an internal name
 *
 */

_PUBLIC_ NTSTATUS gensec_start_mech_by_name(struct gensec_security *gensec_security, 
					const char *name) 
{
	gensec_security->ops = gensec_security_by_name(gensec_security, name);
	if (!gensec_security->ops) {
		DEBUG(3, ("Could not find GENSEC backend for name=%s\n", name));
		return NT_STATUS_INVALID_PARAMETER;
	}
	return gensec_start_mech(gensec_security);
}

/*
  wrappers for the gensec function pointers
*/
_PUBLIC_ NTSTATUS gensec_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)
{
	if (!gensec_security->ops->unseal_packet) {
		return NT_STATUS_NOT_IMPLEMENTED;
	}
	if (!gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
		return NT_STATUS_INVALID_PARAMETER;
	}
	
	return gensec_security->ops->unseal_packet(gensec_security, mem_ctx, 
						   data, length, 
						   whole_pdu, pdu_length, 
						   sig);
}

_PUBLIC_ NTSTATUS gensec_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)
{
	if (!gensec_security->ops->check_packet) {
		return NT_STATUS_NOT_IMPLEMENTED;
	}
	if (!gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
		return NT_STATUS_INVALID_PARAMETER;
	}
	
	return gensec_security->ops->check_packet(gensec_security, mem_ctx, data, length, whole_pdu, pdu_length, sig);
}

_PUBLIC_ NTSTATUS gensec_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)
{
	if (!gensec_security->ops->seal_packet) {
		return NT_STATUS_NOT_IMPLEMENTED;
	}
	if (!gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
		return NT_STATUS_INVALID_PARAMETER;
	}
	
	return gensec_security->ops->seal_packet(gensec_security, mem_ctx, data, length, whole_pdu, pdu_length, sig);
}

_PUBLIC_ NTSTATUS gensec_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)
{
	if (!gensec_security->ops->sign_packet) {
		return NT_STATUS_NOT_IMPLEMENTED;
	}
	if (!gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
		return NT_STATUS_INVALID_PARAMETER;
	}
	
	return gensec_security->ops->sign_packet(gensec_security, mem_ctx, data, length, whole_pdu, pdu_length, sig);
}

_PUBLIC_ size_t gensec_sig_size(struct gensec_security *gensec_security, size_t data_size) 
{
	if (!gensec_security->ops->sig_size) {
		return 0;
	}
	if (!gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
		return 0;
	}
	
	return gensec_security->ops->sig_size(gensec_security, data_size);
}

size_t gensec_max_wrapped_size(struct gensec_security *gensec_security) 
{
	if (!gensec_security->ops->max_wrapped_size) {
		return (1 << 17);
	}
	
	return gensec_security->ops->max_wrapped_size(gensec_security);
}

size_t gensec_max_input_size(struct gensec_security *gensec_security) 
{
	if (!gensec_security->ops->max_input_size) {
		return (1 << 17) - gensec_sig_size(gensec_security, 1 << 17);
	}
	
	return gensec_security->ops->max_input_size(gensec_security);
}

_PUBLIC_ NTSTATUS gensec_wrap(struct gensec_security *gensec_security, 
		     TALLOC_CTX *mem_ctx, 
		     const DATA_BLOB *in, 
		     DATA_BLOB *out) 
{
	if (!gensec_security->ops->wrap) {
		return NT_STATUS_NOT_IMPLEMENTED;
	}
	return gensec_security->ops->wrap(gensec_security, mem_ctx, in, out);
}

_PUBLIC_ NTSTATUS gensec_unwrap(struct gensec_security *gensec_security, 
		       TALLOC_CTX *mem_ctx, 
		       const DATA_BLOB *in, 
		       DATA_BLOB *out) 
{
	if (!gensec_security->ops->unwrap) {
		return NT_STATUS_NOT_IMPLEMENTED;
	}
	return gensec_security->ops->unwrap(gensec_security, mem_ctx, in, out);
}

_PUBLIC_ NTSTATUS gensec_session_key(struct gensec_security *gensec_security, 
			    DATA_BLOB *session_key)
{
	if (!gensec_security->ops->session_key) {
		return NT_STATUS_NOT_IMPLEMENTED;
	}
	if (!gensec_have_feature(gensec_security, GENSEC_FEATURE_SESSION_KEY)) {
		return NT_STATUS_NO_USER_SESSION_KEY;
	}
	
	return gensec_security->ops->session_key(gensec_security, session_key);
}

/** 
 * Return the credentials of a logged on user, including session keys
 * etc.
 *
 * Only valid after a successful authentication
 *
 * May only be called once per authentication.
 *
 */

_PUBLIC_ NTSTATUS gensec_session_info(struct gensec_security *gensec_security, 
			     struct auth_session_info **session_info)
{
	if (!gensec_security->ops->session_info) {
		return NT_STATUS_NOT_IMPLEMENTED;
	}
	return gensec_security->ops->session_info(gensec_security, session_info);
}

/**
 * Next state function for the GENSEC state machine
 * 
 * @param gensec_security GENSEC 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. 
 */

_PUBLIC_ NTSTATUS gensec_update(struct gensec_security *gensec_security, TALLOC_CTX *out_mem_ctx, 
		       const DATA_BLOB in, DATA_BLOB *out) 
{
	return gensec_security->ops->update(gensec_security, out_mem_ctx, in, out);
}

struct gensec_update_state {
	struct tevent_immediate *im;
	struct gensec_security *gensec_security;
	DATA_BLOB in;
	DATA_BLOB out;
};

static void gensec_update_async_trigger(struct tevent_context *ctx,
					struct tevent_immediate *im,
					void *private_data);
/**
 * Next state function for the GENSEC state machine async version
 *
 * @param mem_ctx The memory context for the request
 * @param ev The event context for the request
 * @param gensec_security GENSEC State
 * @param in The request, as a DATA_BLOB
 *
 * @return The request handle or NULL on no memory failure
 */

_PUBLIC_ struct tevent_req *gensec_update_send(TALLOC_CTX *mem_ctx,
					       struct tevent_context *ev,
					       struct gensec_security *gensec_security,
					       const DATA_BLOB in)
{
	struct tevent_req *req;
	struct gensec_update_state *state = NULL;

	req = tevent_req_create(mem_ctx, &state,
				struct gensec_update_state);
	if (req == NULL) {
		return NULL;
	}

	state->gensec_security		= gensec_security;
	state->in			= in;
	state->out			= data_blob(NULL, 0);
	state->im			= tevent_create_immediate(state);
	if (tevent_req_nomem(state->im, req)) {
		return tevent_req_post(req, ev);
	}

	tevent_schedule_immediate(state->im, ev,
				  gensec_update_async_trigger,
				  req);

	return req;
}

static void gensec_update_async_trigger(struct tevent_context *ctx,
					struct tevent_immediate *im,
					void *private_data)
{
	struct tevent_req *req =
		talloc_get_type_abort(private_data, struct tevent_req);
	struct gensec_update_state *state =
		tevent_req_data(req, struct gensec_update_state);
	NTSTATUS status;

	status = gensec_update(state->gensec_security, state,
			       state->in, &state->out);
	if (tevent_req_nterror(req, status)) {
		return;
	}

	tevent_req_done(req);
}

/**
 * Next state function for the GENSEC state machine
 * 
 * @param req request state
 * @param out_mem_ctx The TALLOC_CTX for *out to be allocated on
 * @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. 
 */
_PUBLIC_ NTSTATUS gensec_update_recv(struct tevent_req *req,
				     TALLOC_CTX *out_mem_ctx,
				     DATA_BLOB *out)
{
	struct gensec_update_state *state =
		tevent_req_data(req, struct gensec_update_state);
	NTSTATUS status;

	if (tevent_req_is_nterror(req, &status)) {
		if (!NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
			tevent_req_received(req);
			return status;
		}
	} else {
		status = NT_STATUS_OK;
	}

	*out = state->out;
	talloc_steal(out_mem_ctx, out->data);

	tevent_req_received(req);
	return status;
}

/** 
 * Set the requirement for a certain feature on the connection
 *
 */

_PUBLIC_ void gensec_want_feature(struct gensec_security *gensec_security,
			 uint32_t feature) 
{
	if (!gensec_security->ops || !gensec_security->ops->want_feature) {
		gensec_security->want_features |= feature;
		return;
	}
	gensec_security->ops->want_feature(gensec_security, feature);
}

/** 
 * Check the requirement for a certain feature on the connection
 *
 */

_PUBLIC_ bool gensec_have_feature(struct gensec_security *gensec_security,
			 uint32_t feature) 
{
	if (!gensec_security->ops->have_feature) {
		return false;
	}
	
	/* We might 'have' features that we don't 'want', because the
	 * other end demanded them, or we can't neotiate them off */
	return gensec_security->ops->have_feature(gensec_security, feature);
}

/** 
 * Associate a credentials structure with a GENSEC context - talloc_reference()s it to the context 
 *
 */

_PUBLIC_ NTSTATUS gensec_set_credentials(struct gensec_security *gensec_security, struct cli_credentials *credentials) 
{
	gensec_security->credentials = talloc_reference(gensec_security, credentials);
	NT_STATUS_HAVE_NO_MEMORY(gensec_security->credentials);
	gensec_want_feature(gensec_security, cli_credentials_get_gensec_features(gensec_security->credentials));
	return NT_STATUS_OK;
}

/** 
 * Return the credentials structure associated with a GENSEC context
 *
 */

_PUBLIC_ struct cli_credentials *gensec_get_credentials(struct gensec_security *gensec_security) 
{
	if (!gensec_security) {
		return NULL;
	}
	return gensec_security->credentials;
}

/** 
 * Set the target service (such as 'http' or 'host') on a GENSEC context - ensures it is talloc()ed 
 *
 */

_PUBLIC_ NTSTATUS gensec_set_target_service(struct gensec_security *gensec_security, const char *service) 
{
	gensec_security->target.service = talloc_strdup(gensec_security, service);
	if (!gensec_security->target.service) {
		return NT_STATUS_NO_MEMORY;
	}
	return NT_STATUS_OK;
}

_PUBLIC_ const char *gensec_get_target_service(struct gensec_security *gensec_security) 
{
	if (gensec_security->target.service) {
		return gensec_security->target.service;
	}

	return "host";
}

/** 
 * Set the target hostname (suitable for kerberos resolutation) on a GENSEC context - ensures it is talloc()ed 
 *
 */

_PUBLIC_ NTSTATUS gensec_set_target_hostname(struct gensec_security *gensec_security, const char *hostname) 
{
	gensec_security->target.hostname = talloc_strdup(gensec_security, hostname);
	if (hostname && !gensec_security->target.hostname) {
		return NT_STATUS_NO_MEMORY;
	}
	return NT_STATUS_OK;
}

_PUBLIC_ const char *gensec_get_target_hostname(struct gensec_security *gensec_security) 
{
	/* We allow the target hostname to be overriden for testing purposes */
	if (gensec_security->settings->target_hostname) {
		return gensec_security->settings->target_hostname;
	}

	if (gensec_security->target.hostname) {
		return gensec_security->target.hostname;
	}

	/* We could add use the 'set sockaddr' call, and do a reverse
	 * lookup, but this would be both insecure (compromising the
	 * way kerberos works) and add DNS timeouts */
	return NULL;
}

/**
 * Set (and talloc_reference) local and peer socket addresses onto a socket
 * context on the GENSEC context.
 *
 * This is so that kerberos can include these addresses in
 * cryptographic tokens, to avoid certain attacks.
 */

/**
 * @brief Set the local gensec address.
 *
 * @param  gensec_security   The gensec security context to use.
 *
 * @param  remote       The local address to set.
 *
 * @return              On success NT_STATUS_OK is returned or an NT_STATUS
 *                      error.
 */
_PUBLIC_ NTSTATUS gensec_set_local_address(struct gensec_security *gensec_security,
		const struct tsocket_address *local)
{
	TALLOC_FREE(gensec_security->local_addr);

	if (local == NULL) {
		return NT_STATUS_OK;
	}

	gensec_security->local_addr = tsocket_address_copy(local, gensec_security);
	if (gensec_security->local_addr == NULL) {
		return NT_STATUS_NO_MEMORY;
	}

	return NT_STATUS_OK;
}

/**
 * @brief Set the remote gensec address.
 *
 * @param  gensec_security   The gensec security context to use.
 *
 * @param  remote       The remote address to set.
 *
 * @return              On success NT_STATUS_OK is returned or an NT_STATUS
 *                      error.
 */
_PUBLIC_ NTSTATUS gensec_set_remote_address(struct gensec_security *gensec_security,
		const struct tsocket_address *remote)
{
	TALLOC_FREE(gensec_security->remote_addr);

	if (remote == NULL) {
		return NT_STATUS_OK;
	}

	gensec_security->remote_addr = tsocket_address_copy(remote, gensec_security);
	if (gensec_security->remote_addr == NULL) {
		return NT_STATUS_NO_MEMORY;
	}

	return NT_STATUS_OK;
}

/**
 * @brief Get the local address from a gensec security context.
 *
 * @param  gensec_security   The security context to get the address from.
 *
 * @return              The address as tsocket_address which could be NULL if
 *                      no address is set.
 */
_PUBLIC_ const struct tsocket_address *gensec_get_local_address(struct gensec_security *gensec_security)
{
	if (gensec_security == NULL) {
		return NULL;
	}
	return gensec_security->local_addr;
}

/**
 * @brief Get the remote address from a gensec security context.
 *
 * @param  gensec_security   The security context to get the address from.
 *
 * @return              The address as tsocket_address which could be NULL if
 *                      no address is set.
 */
_PUBLIC_ const struct tsocket_address *gensec_get_remote_address(struct gensec_security *gensec_security)
{
	if (gensec_security == NULL) {
		return NULL;
	}
	return gensec_security->remote_addr;
}

/** 
 * Set the target principal (assuming it it known, say from the SPNEGO reply)
 *  - ensures it is talloc()ed 
 *
 */

_PUBLIC_ NTSTATUS gensec_set_target_principal(struct gensec_security *gensec_security, const char *principal)
{
	gensec_security->target.principal = talloc_strdup(gensec_security, principal);
	if (!gensec_security->target.principal) {
		return NT_STATUS_NO_MEMORY;
	}
	return NT_STATUS_OK;
}

const char *gensec_get_target_principal(struct gensec_security *gensec_security) 
{
	if (gensec_security->target.principal) {
		return gensec_security->target.principal;
	}

	return NULL;
}

NTSTATUS gensec_generate_session_info(TALLOC_CTX *mem_ctx,
				      struct gensec_security *gensec_security,
				      struct auth_serversupplied_info *server_info,
				      struct auth_session_info **session_info)
{
	NTSTATUS nt_status;
	if (gensec_security->auth_context) {
		uint32_t flags = AUTH_SESSION_INFO_DEFAULT_GROUPS;
		if (server_info->authenticated) {
			flags |= AUTH_SESSION_INFO_AUTHENTICATED;
		}
		nt_status = gensec_security->auth_context->generate_session_info(mem_ctx, gensec_security->auth_context,
										 server_info,
										 flags,
										 session_info);
	} else {
		nt_status = auth_generate_simple_session_info(mem_ctx,
							      server_info, session_info);
	}
	return nt_status;
}

/*
  register a GENSEC backend. 

  The 'name' can be later used by other backends to find the operations
  structure for this backend.
*/
NTSTATUS gensec_register(const struct gensec_security_ops *ops)
{
	if (gensec_security_by_name(NULL, ops->name) != NULL) {
		/* its already registered! */
		DEBUG(0,("GENSEC backend '%s' already registered\n", 
			 ops->name));
		return NT_STATUS_OBJECT_NAME_COLLISION;
	}

	generic_security_ops = talloc_realloc(talloc_autofree_context(), 
					      generic_security_ops, 
					      struct gensec_security_ops *, 
					      gensec_num_backends+2);
	if (!generic_security_ops) {
		return NT_STATUS_NO_MEMORY;
	}

	generic_security_ops[gensec_num_backends] = discard_const_p(struct gensec_security_ops, ops);
	gensec_num_backends++;
	generic_security_ops[gensec_num_backends] = NULL;

	DEBUG(3,("GENSEC backend '%s' registered\n", 
		 ops->name));

	return NT_STATUS_OK;
}

/*
  return the GENSEC interface version, and the size of some critical types
  This can be used by backends to either detect compilation errors, or provide
  multiple implementations for different smbd compilation options in one module
*/
const struct gensec_critical_sizes *gensec_interface_version(void)
{
	static const struct gensec_critical_sizes critical_sizes = {
		GENSEC_INTERFACE_VERSION,
		sizeof(struct gensec_security_ops),
		sizeof(struct gensec_security),
	};

	return &critical_sizes;
}

static int sort_gensec(struct gensec_security_ops **gs1, struct gensec_security_ops **gs2) {
	return (*gs2)->priority - (*gs1)->priority;
}

int gensec_setting_int(struct gensec_settings *settings, const char *mechanism, const char *name, int default_value)
{
	return lp_parm_int(settings->lp_ctx, NULL, mechanism, name, default_value);
}

bool gensec_setting_bool(struct gensec_settings *settings, const char *mechanism, const char *name, bool default_value)
{
	return lp_parm_bool(settings->lp_ctx, NULL, mechanism, name, default_value);
}

/*
  initialise the GENSEC subsystem
*/
_PUBLIC_ NTSTATUS gensec_init(struct loadparm_context *lp_ctx)
{
	static bool initialized = false;
	extern NTSTATUS gensec_sasl_init(void);
	extern NTSTATUS gensec_krb5_init(void);
	extern NTSTATUS gensec_schannel_init(void);
	extern NTSTATUS gensec_spnego_init(void);
	extern NTSTATUS gensec_gssapi_init(void);
	extern NTSTATUS gensec_ntlmssp_init(void);

	init_module_fn static_init[] = { STATIC_gensec_MODULES };
	init_module_fn *shared_init;

	if (initialized) return NT_STATUS_OK;
	initialized = true;
	
	shared_init = load_samba_modules(NULL, lp_ctx, "gensec");

	run_init_functions(static_init);
	run_init_functions(shared_init);

	talloc_free(shared_init);

	TYPESAFE_QSORT(generic_security_ops, gensec_num_backends, sort_gensec);
	
	return NT_STATUS_OK;
}