summaryrefslogtreecommitdiffstats
path: root/epan/dissectors/packet-credssp.c
blob: 44b71b092f06257695a00deb1353a1debddc740e (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
/* Do not modify this file. Changes will be overwritten.                      */
/* Generated automatically by the ASN.1 to Wireshark dissector compiler       */
/* packet-credssp.c                                                           */
/* asn2wrs.py -b -C -L -p credssp -c ./credssp.cnf -s ./packet-credssp-template -D . -O ../.. CredSSP.asn */

/* packet-credssp.c
 * Routines for CredSSP (Credential Security Support Provider) packet dissection
 * Graeme Lunt 2011
 *
 * Wireshark - Network traffic analyzer
 * By Gerald Combs <gerald@wireshark.org>
 * Copyright 1998 Gerald Combs
 *
 * SPDX-License-Identifier: GPL-2.0-or-later
 */

#include "config.h"

#include <epan/packet.h>
#include <epan/asn1.h>
#include <epan/tap.h>
#include <epan/exported_pdu.h>

#include "packet-ber.h"
#include "packet-gssapi.h"
#include "packet-kerberos.h"
#include "packet-ntlmssp.h"
#include "packet-credssp.h"

#define PNAME  "Credential Security Support Provider"
#define PSNAME "CredSSP"
#define PFNAME "credssp"

#define TS_PASSWORD_CREDS   1
#define TS_SMARTCARD_CREDS  2
#define TS_REMOTEGUARD_CREDS  6

static gint creds_type;
static gint credssp_ver;

static char kerberos_pname[] = "K\0e\0r\0b\0e\0r\0o\0s";
static char ntlm_pname[] = "N\0T\0L\0M";

#define TS_RGC_UNKNOWN	0
#define TS_RGC_KERBEROS	1
#define TS_RGC_NTLM	2

static gint credssp_TS_RGC_package;

static gint exported_pdu_tap = -1;

/* Initialize the protocol and registered fields */
static int proto_credssp = -1;

/* List of dissectors to call for negoToken data */
static heur_dissector_list_t credssp_heur_subdissector_list;

static dissector_handle_t gssapi_handle;
static dissector_handle_t gssapi_wrap_handle;

static int hf_credssp_TSPasswordCreds = -1;   /* TSPasswordCreds */
static int hf_credssp_TSSmartCardCreds = -1;  /* TSSmartCardCreds */
static int hf_credssp_TSRemoteGuardCreds = -1;/* TSRemoteGuardCreds */
static int hf_credssp_TSCredentials = -1;     /* TSCredentials */
static int hf_credssp_decr_PublicKeyAuth = -1;/* decr_PublicKeyAuth */
static int hf_credssp_TSRequest_PDU = -1;         /* TSRequest */
static int hf_credssp_NegoData_item = -1;         /* NegoData_item */
static int hf_credssp_negoToken = -1;             /* T_negoToken */
static int hf_credssp_domainName = -1;            /* OCTET_STRING */
static int hf_credssp_userName = -1;              /* OCTET_STRING */
static int hf_credssp_password = -1;              /* OCTET_STRING */
static int hf_credssp_keySpec = -1;               /* INTEGER */
static int hf_credssp_cardName = -1;              /* OCTET_STRING */
static int hf_credssp_readerName = -1;            /* OCTET_STRING */
static int hf_credssp_containerName = -1;         /* OCTET_STRING */
static int hf_credssp_cspName = -1;               /* OCTET_STRING */
static int hf_credssp_pin = -1;                   /* OCTET_STRING */
static int hf_credssp_cspData = -1;               /* TSCspDataDetail */
static int hf_credssp_userHint = -1;              /* OCTET_STRING */
static int hf_credssp_domainHint = -1;            /* OCTET_STRING */
static int hf_credssp_packageName = -1;           /* T_packageName */
static int hf_credssp_credBuffer = -1;            /* T_credBuffer */
static int hf_credssp_logonCred = -1;             /* TSRemoteGuardPackageCred */
static int hf_credssp_supplementalCreds = -1;     /* SEQUENCE_OF_TSRemoteGuardPackageCred */
static int hf_credssp_supplementalCreds_item = -1;  /* TSRemoteGuardPackageCred */
static int hf_credssp_credType = -1;              /* T_credType */
static int hf_credssp_credentials = -1;           /* T_credentials */
static int hf_credssp_version = -1;               /* T_version */
static int hf_credssp_negoTokens = -1;            /* NegoData */
static int hf_credssp_authInfo = -1;              /* T_authInfo */
static int hf_credssp_pubKeyAuth = -1;            /* T_pubKeyAuth */
static int hf_credssp_errorCode = -1;             /* T_errorCode */
static int hf_credssp_clientNonce = -1;           /* T_clientNonce */

/* Initialize the subtree pointers */
static gint ett_credssp = -1;
static gint ett_credssp_RGC_CredBuffer = -1;

static gint ett_credssp_NegoData = -1;
static gint ett_credssp_NegoData_item = -1;
static gint ett_credssp_TSPasswordCreds = -1;
static gint ett_credssp_TSCspDataDetail = -1;
static gint ett_credssp_TSSmartCardCreds = -1;
static gint ett_credssp_TSRemoteGuardPackageCred = -1;
static gint ett_credssp_TSRemoteGuardCreds = -1;
static gint ett_credssp_SEQUENCE_OF_TSRemoteGuardPackageCred = -1;
static gint ett_credssp_TSCredentials = -1;
static gint ett_credssp_TSRequest = -1;



static int
dissect_credssp_T_negoToken(bool implicit_tag _U_, tvbuff_t *tvb _U_, int offset _U_, asn1_ctx_t *actx _U_, proto_tree *tree _U_, int hf_index _U_) {
	tvbuff_t *token_tvb = NULL;

	  offset = dissect_ber_octet_string(implicit_tag, actx, tree, tvb, offset, hf_index,
                                       &token_tvb);


	if(token_tvb != NULL)
		call_dissector(gssapi_handle, token_tvb, actx->pinfo, tree);



  return offset;
}


static const ber_sequence_t NegoData_item_sequence[] = {
  { &hf_credssp_negoToken   , BER_CLASS_CON, 0, 0, dissect_credssp_T_negoToken },
  { NULL, 0, 0, 0, NULL }
};

static int
dissect_credssp_NegoData_item(bool implicit_tag _U_, tvbuff_t *tvb _U_, int offset _U_, asn1_ctx_t *actx _U_, proto_tree *tree _U_, int hf_index _U_) {
  offset = dissect_ber_sequence(implicit_tag, actx, tree, tvb, offset,
                                   NegoData_item_sequence, hf_index, ett_credssp_NegoData_item);

  return offset;
}


static const ber_sequence_t NegoData_sequence_of[1] = {
  { &hf_credssp_NegoData_item, BER_CLASS_UNI, BER_UNI_TAG_SEQUENCE, BER_FLAGS_NOOWNTAG, dissect_credssp_NegoData_item },
};

static int
dissect_credssp_NegoData(bool implicit_tag _U_, tvbuff_t *tvb _U_, int offset _U_, asn1_ctx_t *actx _U_, proto_tree *tree _U_, int hf_index _U_) {
  offset = dissect_ber_sequence_of(implicit_tag, actx, tree, tvb, offset,
                                      NegoData_sequence_of, hf_index, ett_credssp_NegoData);

  return offset;
}



static int
dissect_credssp_OCTET_STRING(bool implicit_tag _U_, tvbuff_t *tvb _U_, int offset _U_, asn1_ctx_t *actx _U_, proto_tree *tree _U_, int hf_index _U_) {
  offset = dissect_ber_octet_string(implicit_tag, actx, tree, tvb, offset, hf_index,
                                       NULL);

  return offset;
}


static const ber_sequence_t TSPasswordCreds_sequence[] = {
  { &hf_credssp_domainName  , BER_CLASS_CON, 0, 0, dissect_credssp_OCTET_STRING },
  { &hf_credssp_userName    , BER_CLASS_CON, 1, 0, dissect_credssp_OCTET_STRING },
  { &hf_credssp_password    , BER_CLASS_CON, 2, 0, dissect_credssp_OCTET_STRING },
  { NULL, 0, 0, 0, NULL }
};

static int
dissect_credssp_TSPasswordCreds(bool implicit_tag _U_, tvbuff_t *tvb _U_, int offset _U_, asn1_ctx_t *actx _U_, proto_tree *tree _U_, int hf_index _U_) {
  offset = dissect_ber_sequence(implicit_tag, actx, tree, tvb, offset,
                                   TSPasswordCreds_sequence, hf_index, ett_credssp_TSPasswordCreds);

  return offset;
}



static int
dissect_credssp_INTEGER(bool implicit_tag _U_, tvbuff_t *tvb _U_, int offset _U_, asn1_ctx_t *actx _U_, proto_tree *tree _U_, int hf_index _U_) {
  offset = dissect_ber_integer(implicit_tag, actx, tree, tvb, offset, hf_index,
                                                NULL);

  return offset;
}


static const ber_sequence_t TSCspDataDetail_sequence[] = {
  { &hf_credssp_keySpec     , BER_CLASS_CON, 0, 0, dissect_credssp_INTEGER },
  { &hf_credssp_cardName    , BER_CLASS_CON, 1, BER_FLAGS_OPTIONAL, dissect_credssp_OCTET_STRING },
  { &hf_credssp_readerName  , BER_CLASS_CON, 2, BER_FLAGS_OPTIONAL, dissect_credssp_OCTET_STRING },
  { &hf_credssp_containerName, BER_CLASS_CON, 3, BER_FLAGS_OPTIONAL, dissect_credssp_OCTET_STRING },
  { &hf_credssp_cspName     , BER_CLASS_CON, 4, BER_FLAGS_OPTIONAL, dissect_credssp_OCTET_STRING },
  { NULL, 0, 0, 0, NULL }
};

static int
dissect_credssp_TSCspDataDetail(bool implicit_tag _U_, tvbuff_t *tvb _U_, int offset _U_, asn1_ctx_t *actx _U_, proto_tree *tree _U_, int hf_index _U_) {
  offset = dissect_ber_sequence(implicit_tag, actx, tree, tvb, offset,
                                   TSCspDataDetail_sequence, hf_index, ett_credssp_TSCspDataDetail);

  return offset;
}


static const ber_sequence_t TSSmartCardCreds_sequence[] = {
  { &hf_credssp_pin         , BER_CLASS_CON, 0, 0, dissect_credssp_OCTET_STRING },
  { &hf_credssp_cspData     , BER_CLASS_CON, 1, 0, dissect_credssp_TSCspDataDetail },
  { &hf_credssp_userHint    , BER_CLASS_CON, 2, BER_FLAGS_OPTIONAL, dissect_credssp_OCTET_STRING },
  { &hf_credssp_domainHint  , BER_CLASS_CON, 3, BER_FLAGS_OPTIONAL, dissect_credssp_OCTET_STRING },
  { NULL, 0, 0, 0, NULL }
};

static int
dissect_credssp_TSSmartCardCreds(bool implicit_tag _U_, tvbuff_t *tvb _U_, int offset _U_, asn1_ctx_t *actx _U_, proto_tree *tree _U_, int hf_index _U_) {
  offset = dissect_ber_sequence(implicit_tag, actx, tree, tvb, offset,
                                   TSSmartCardCreds_sequence, hf_index, ett_credssp_TSSmartCardCreds);

  return offset;
}



static int
dissect_credssp_T_packageName(bool implicit_tag _U_, tvbuff_t *tvb _U_, int offset _U_, asn1_ctx_t *actx _U_, proto_tree *tree _U_, int hf_index _U_) {
	tvbuff_t *pname = NULL;

	offset = dissect_ber_octet_string(implicit_tag, actx, NULL, tvb, offset, hf_index, &pname);

	if(pname != NULL) {
		gint nlen = tvb_captured_length(pname);

		if (nlen == sizeof(kerberos_pname) && memcmp(tvb_get_ptr(pname, 0, nlen), kerberos_pname, nlen) == 0) {
			credssp_TS_RGC_package = TS_RGC_KERBEROS;
		} else if (nlen == sizeof(ntlm_pname) && memcmp(tvb_get_ptr(pname, 0, nlen), ntlm_pname, nlen) == 0) {
			credssp_TS_RGC_package = TS_RGC_NTLM;
		}
		proto_tree_add_item(tree, hf_index, pname, 0, -1, ENC_UTF_16|ENC_LITTLE_ENDIAN);
	}


  return offset;
}



static int
dissect_credssp_T_credBuffer(bool implicit_tag _U_, tvbuff_t *tvb _U_, int offset _U_, asn1_ctx_t *actx _U_, proto_tree *tree _U_, int hf_index _U_) {
	tvbuff_t *creds= NULL;
	proto_tree *subtree;

	  offset = dissect_ber_octet_string(implicit_tag, actx, tree, tvb, offset, hf_index,
                                       &creds);


	if (!creds)
		return offset;

	switch(credssp_TS_RGC_package) {
	case TS_RGC_KERBEROS:
		subtree = proto_item_add_subtree(actx->created_item, ett_credssp_RGC_CredBuffer);
		dissect_kerberos_KERB_TICKET_LOGON(creds, 0, actx, subtree);
		break;
	case TS_RGC_NTLM:
		subtree = proto_item_add_subtree(actx->created_item, ett_credssp_RGC_CredBuffer);
		dissect_ntlmssp_NTLM_REMOTE_SUPPLEMENTAL_CREDENTIAL(creds, 0, subtree);
		break;
	}


  return offset;
}


static const ber_sequence_t TSRemoteGuardPackageCred_sequence[] = {
  { &hf_credssp_packageName , BER_CLASS_CON, 0, 0, dissect_credssp_T_packageName },
  { &hf_credssp_credBuffer  , BER_CLASS_CON, 1, 0, dissect_credssp_T_credBuffer },
  { NULL, 0, 0, 0, NULL }
};

static int
dissect_credssp_TSRemoteGuardPackageCred(bool implicit_tag _U_, tvbuff_t *tvb _U_, int offset _U_, asn1_ctx_t *actx _U_, proto_tree *tree _U_, int hf_index _U_) {
  offset = dissect_ber_sequence(implicit_tag, actx, tree, tvb, offset,
                                   TSRemoteGuardPackageCred_sequence, hf_index, ett_credssp_TSRemoteGuardPackageCred);

  return offset;
}


static const ber_sequence_t SEQUENCE_OF_TSRemoteGuardPackageCred_sequence_of[1] = {
  { &hf_credssp_supplementalCreds_item, BER_CLASS_UNI, BER_UNI_TAG_SEQUENCE, BER_FLAGS_NOOWNTAG, dissect_credssp_TSRemoteGuardPackageCred },
};

static int
dissect_credssp_SEQUENCE_OF_TSRemoteGuardPackageCred(bool implicit_tag _U_, tvbuff_t *tvb _U_, int offset _U_, asn1_ctx_t *actx _U_, proto_tree *tree _U_, int hf_index _U_) {
  offset = dissect_ber_sequence_of(implicit_tag, actx, tree, tvb, offset,
                                      SEQUENCE_OF_TSRemoteGuardPackageCred_sequence_of, hf_index, ett_credssp_SEQUENCE_OF_TSRemoteGuardPackageCred);

  return offset;
}


static const ber_sequence_t TSRemoteGuardCreds_sequence[] = {
  { &hf_credssp_logonCred   , BER_CLASS_CON, 0, 0, dissect_credssp_TSRemoteGuardPackageCred },
  { &hf_credssp_supplementalCreds, BER_CLASS_CON, 1, BER_FLAGS_OPTIONAL, dissect_credssp_SEQUENCE_OF_TSRemoteGuardPackageCred },
  { NULL, 0, 0, 0, NULL }
};

static int
dissect_credssp_TSRemoteGuardCreds(bool implicit_tag _U_, tvbuff_t *tvb _U_, int offset _U_, asn1_ctx_t *actx _U_, proto_tree *tree _U_, int hf_index _U_) {
  offset = dissect_ber_sequence(implicit_tag, actx, tree, tvb, offset,
                                   TSRemoteGuardCreds_sequence, hf_index, ett_credssp_TSRemoteGuardCreds);

  return offset;
}



static int
dissect_credssp_T_credType(bool implicit_tag _U_, tvbuff_t *tvb _U_, int offset _U_, asn1_ctx_t *actx _U_, proto_tree *tree _U_, int hf_index _U_) {
  offset = dissect_ber_integer(implicit_tag, actx, tree, tvb, offset, hf_index,
                                                &creds_type);

  return offset;
}



static int
dissect_credssp_T_credentials(bool implicit_tag _U_, tvbuff_t *tvb _U_, int offset _U_, asn1_ctx_t *actx _U_, proto_tree *tree _U_, int hf_index _U_) {
	tvbuff_t *creds_tvb = NULL;

	  offset = dissect_ber_octet_string(implicit_tag, actx, tree, tvb, offset, hf_index,
                                       &creds_tvb);


	switch(creds_type) {
	case TS_PASSWORD_CREDS:
		dissect_credssp_TSPasswordCreds(FALSE, creds_tvb, 0, actx, tree, hf_credssp_TSPasswordCreds);
		break;
	case TS_SMARTCARD_CREDS:
		dissect_credssp_TSSmartCardCreds(FALSE, creds_tvb, 0, actx, tree, hf_credssp_TSSmartCardCreds);
		break;
	case TS_REMOTEGUARD_CREDS:
		dissect_credssp_TSRemoteGuardCreds(FALSE, creds_tvb, 0, actx, tree, hf_credssp_TSRemoteGuardCreds);
		break;
	}



  return offset;
}


static const ber_sequence_t TSCredentials_sequence[] = {
  { &hf_credssp_credType    , BER_CLASS_CON, 0, 0, dissect_credssp_T_credType },
  { &hf_credssp_credentials , BER_CLASS_CON, 1, 0, dissect_credssp_T_credentials },
  { NULL, 0, 0, 0, NULL }
};

static int
dissect_credssp_TSCredentials(bool implicit_tag _U_, tvbuff_t *tvb _U_, int offset _U_, asn1_ctx_t *actx _U_, proto_tree *tree _U_, int hf_index _U_) {
  offset = dissect_ber_sequence(implicit_tag, actx, tree, tvb, offset,
                                   TSCredentials_sequence, hf_index, ett_credssp_TSCredentials);

  return offset;
}



static int
dissect_credssp_T_version(bool implicit_tag _U_, tvbuff_t *tvb _U_, int offset _U_, asn1_ctx_t *actx _U_, proto_tree *tree _U_, int hf_index _U_) {
  offset = dissect_ber_integer(implicit_tag, actx, tree, tvb, offset, hf_index,
                                                &credssp_ver);

  return offset;
}



static int
dissect_credssp_T_authInfo(bool implicit_tag _U_, tvbuff_t *tvb _U_, int offset _U_, asn1_ctx_t *actx _U_, proto_tree *tree _U_, int hf_index _U_) {
	tvbuff_t *auth_tvb = NULL;
	tvbuff_t *decr_tvb = NULL;
	gssapi_encrypt_info_t gssapi_encrypt;

	  offset = dissect_ber_octet_string(implicit_tag, actx, tree, tvb, offset, hf_index,
                                       &auth_tvb);


	memset(&gssapi_encrypt, 0, sizeof(gssapi_encrypt));
	gssapi_encrypt.decrypt_gssapi_tvb=DECRYPT_GSSAPI_NORMAL;
	call_dissector_with_data(gssapi_wrap_handle, auth_tvb, actx->pinfo, tree, &gssapi_encrypt);
	decr_tvb = gssapi_encrypt.gssapi_decrypted_tvb;

	if(decr_tvb != NULL)
		dissect_credssp_TSCredentials(FALSE, decr_tvb, 0, actx, tree, hf_credssp_TSCredentials);


  return offset;
}



static int
dissect_credssp_T_pubKeyAuth(bool implicit_tag _U_, tvbuff_t *tvb _U_, int offset _U_, asn1_ctx_t *actx _U_, proto_tree *tree _U_, int hf_index _U_) {
	tvbuff_t *auth_tvb = NULL;
	tvbuff_t *decr_tvb = NULL;
	gssapi_encrypt_info_t gssapi_encrypt;

	  offset = dissect_ber_octet_string(implicit_tag, actx, tree, tvb, offset, hf_index,
                                       &auth_tvb);


	memset(&gssapi_encrypt, 0, sizeof(gssapi_encrypt));
	gssapi_encrypt.decrypt_gssapi_tvb=DECRYPT_GSSAPI_NORMAL;
	call_dissector_with_data(gssapi_wrap_handle, auth_tvb, actx->pinfo, tree, &gssapi_encrypt);
	decr_tvb = gssapi_encrypt.gssapi_decrypted_tvb;

	if(decr_tvb != NULL)
		proto_tree_add_item(tree, hf_credssp_decr_PublicKeyAuth, decr_tvb, 0, -1, ENC_NA);


  return offset;
}



static int
dissect_credssp_T_errorCode(bool implicit_tag _U_, tvbuff_t *tvb _U_, int offset _U_, asn1_ctx_t *actx _U_, proto_tree *tree _U_, int hf_index _U_) {

	if (credssp_ver < 3) {
		return 0;
	}

	  offset = dissect_ber_integer(implicit_tag, actx, tree, tvb, offset, hf_index,
                                                NULL);




  return offset;
}



static int
dissect_credssp_T_clientNonce(bool implicit_tag _U_, tvbuff_t *tvb _U_, int offset _U_, asn1_ctx_t *actx _U_, proto_tree *tree _U_, int hf_index _U_) {

	if (credssp_ver < 5) {
		return 0;
	}

	  offset = dissect_ber_octet_string(implicit_tag, actx, tree, tvb, offset, hf_index,
                                       NULL);




  return offset;
}


static const ber_sequence_t TSRequest_sequence[] = {
  { &hf_credssp_version     , BER_CLASS_CON, 0, 0, dissect_credssp_T_version },
  { &hf_credssp_negoTokens  , BER_CLASS_CON, 1, BER_FLAGS_OPTIONAL, dissect_credssp_NegoData },
  { &hf_credssp_authInfo    , BER_CLASS_CON, 2, BER_FLAGS_OPTIONAL, dissect_credssp_T_authInfo },
  { &hf_credssp_pubKeyAuth  , BER_CLASS_CON, 3, BER_FLAGS_OPTIONAL, dissect_credssp_T_pubKeyAuth },
  { &hf_credssp_errorCode   , BER_CLASS_CON, 4, BER_FLAGS_OPTIONAL, dissect_credssp_T_errorCode },
  { &hf_credssp_clientNonce , BER_CLASS_CON, 5, BER_FLAGS_OPTIONAL, dissect_credssp_T_clientNonce },
  { NULL, 0, 0, 0, NULL }
};

static int
dissect_credssp_TSRequest(bool implicit_tag _U_, tvbuff_t *tvb _U_, int offset _U_, asn1_ctx_t *actx _U_, proto_tree *tree _U_, int hf_index _U_) {
  offset = dissect_ber_sequence(implicit_tag, actx, tree, tvb, offset,
                                   TSRequest_sequence, hf_index, ett_credssp_TSRequest);

  return offset;
}

/*--- PDUs ---*/

static int dissect_TSRequest_PDU(tvbuff_t *tvb _U_, packet_info *pinfo _U_, proto_tree *tree _U_, void *data _U_) {
  int offset = 0;
  asn1_ctx_t asn1_ctx;
  asn1_ctx_init(&asn1_ctx, ASN1_ENC_BER, TRUE, pinfo);
  offset = dissect_credssp_TSRequest(FALSE, tvb, offset, &asn1_ctx, tree, hf_credssp_TSRequest_PDU);
  return offset;
}


/*
* Dissect CredSSP PDUs
*/
static int
dissect_credssp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree, void *data)
{
	proto_item *item=NULL;
	proto_tree *tree=NULL;

	if(parent_tree){
		item = proto_tree_add_item(parent_tree, proto_credssp, tvb, 0, -1, ENC_NA);
		tree = proto_item_add_subtree(item, ett_credssp);
	}
	col_set_str(pinfo->cinfo, COL_PROTOCOL, "CredSSP");
  	col_clear(pinfo->cinfo, COL_INFO);

	creds_type = -1;
	credssp_ver = -1;

	return dissect_TSRequest_PDU(tvb, pinfo, tree, data);
}

static gboolean
dissect_credssp_heur(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree, void *data _U_)
{
  asn1_ctx_t asn1_ctx;
  int offset = 0;
  gint8 ber_class;
  bool pc;
  gint32 tag;
  guint32 length;
  gint8 ver;

  asn1_ctx_init(&asn1_ctx, ASN1_ENC_BER, TRUE, pinfo);

  /* Look for SEQUENCE, CONTEXT 0, and INTEGER 2 */
  if(tvb_captured_length(tvb) > 7) {
    offset = get_ber_identifier(tvb, offset, &ber_class, &pc, &tag);
    if((ber_class == BER_CLASS_UNI) && (tag == BER_UNI_TAG_SEQUENCE) && (pc == TRUE)) {
      offset = get_ber_length(tvb, offset, NULL, NULL);
      offset = get_ber_identifier(tvb, offset, &ber_class, &pc, &tag);
      if((ber_class == BER_CLASS_CON) && (tag == 0)) {
        offset = get_ber_length(tvb, offset, NULL, NULL);
        offset = get_ber_identifier(tvb, offset, &ber_class, &pc, &tag);
        if((ber_class == BER_CLASS_UNI) && (tag == BER_UNI_TAG_INTEGER)) {
          offset = get_ber_length(tvb, offset, &length, NULL);
          ver = tvb_get_guint8(tvb, offset);
          if((length == 1) && (ver > 1) && (ver < 99)) {
            if (have_tap_listener(exported_pdu_tap)) {
              exp_pdu_data_t *exp_pdu_data = export_pdu_create_common_tags(pinfo, "credssp", EXP_PDU_TAG_DISSECTOR_NAME);

              exp_pdu_data->tvb_captured_length = tvb_captured_length(tvb);
              exp_pdu_data->tvb_reported_length = tvb_reported_length(tvb);
              exp_pdu_data->pdu_tvb = tvb;

              tap_queue_packet(exported_pdu_tap, pinfo, exp_pdu_data);
            }
            dissect_credssp(tvb, pinfo, parent_tree, NULL);
            return TRUE;
          }
        }
      }
    }
  }
  return FALSE;
}


/*--- proto_register_credssp -------------------------------------------*/
void proto_register_credssp(void) {

  /* List of fields */
  static hf_register_info hf[] =
  {
    { &hf_credssp_TSPasswordCreds,
      { "TSPasswordCreds", "credssp.TSPasswordCreds",
        FT_NONE, BASE_NONE, NULL, 0,
        NULL, HFILL }},
    { &hf_credssp_TSSmartCardCreds,
      { "TSSmartCardCreds", "credssp.TSSmartCardCreds",
        FT_NONE, BASE_NONE, NULL, 0,
        NULL, HFILL }},
    { &hf_credssp_TSRemoteGuardCreds,
      { "TSRemoteGuardCreds", "credssp.TSRemoteGuardCreds",
        FT_NONE, BASE_NONE, NULL, 0,
        NULL, HFILL }},
    { &hf_credssp_TSCredentials,
      { "TSCredentials", "credssp.TSCredentials",
        FT_NONE, BASE_NONE, NULL, 0,
        NULL, HFILL }},
    { &hf_credssp_decr_PublicKeyAuth,
      { "Decrypted PublicKeyAuth (sha256)", "credssp.decr_PublicKeyAuth",
        FT_BYTES, BASE_NONE, NULL, 0,
        NULL, HFILL }},
    { &hf_credssp_TSRequest_PDU,
      { "TSRequest", "credssp.TSRequest_element",
        FT_NONE, BASE_NONE, NULL, 0,
        NULL, HFILL }},
    { &hf_credssp_NegoData_item,
      { "NegoData item", "credssp.NegoData_item_element",
        FT_NONE, BASE_NONE, NULL, 0,
        NULL, HFILL }},
    { &hf_credssp_negoToken,
      { "negoToken", "credssp.negoToken",
        FT_BYTES, BASE_NONE, NULL, 0,
        NULL, HFILL }},
    { &hf_credssp_domainName,
      { "domainName", "credssp.domainName",
        FT_BYTES, BASE_NONE, NULL, 0,
        "OCTET_STRING", HFILL }},
    { &hf_credssp_userName,
      { "userName", "credssp.userName",
        FT_BYTES, BASE_NONE, NULL, 0,
        "OCTET_STRING", HFILL }},
    { &hf_credssp_password,
      { "password", "credssp.password",
        FT_BYTES, BASE_NONE, NULL, 0,
        "OCTET_STRING", HFILL }},
    { &hf_credssp_keySpec,
      { "keySpec", "credssp.keySpec",
        FT_INT32, BASE_DEC, NULL, 0,
        "INTEGER", HFILL }},
    { &hf_credssp_cardName,
      { "cardName", "credssp.cardName",
        FT_BYTES, BASE_NONE, NULL, 0,
        "OCTET_STRING", HFILL }},
    { &hf_credssp_readerName,
      { "readerName", "credssp.readerName",
        FT_BYTES, BASE_NONE, NULL, 0,
        "OCTET_STRING", HFILL }},
    { &hf_credssp_containerName,
      { "containerName", "credssp.containerName",
        FT_BYTES, BASE_NONE, NULL, 0,
        "OCTET_STRING", HFILL }},
    { &hf_credssp_cspName,
      { "cspName", "credssp.cspName",
        FT_BYTES, BASE_NONE, NULL, 0,
        "OCTET_STRING", HFILL }},
    { &hf_credssp_pin,
      { "pin", "credssp.pin",
        FT_BYTES, BASE_NONE, NULL, 0,
        "OCTET_STRING", HFILL }},
    { &hf_credssp_cspData,
      { "cspData", "credssp.cspData_element",
        FT_NONE, BASE_NONE, NULL, 0,
        "TSCspDataDetail", HFILL }},
    { &hf_credssp_userHint,
      { "userHint", "credssp.userHint",
        FT_BYTES, BASE_NONE, NULL, 0,
        "OCTET_STRING", HFILL }},
    { &hf_credssp_domainHint,
      { "domainHint", "credssp.domainHint",
        FT_BYTES, BASE_NONE, NULL, 0,
        "OCTET_STRING", HFILL }},
    { &hf_credssp_packageName,
      { "packageName", "credssp.packageName",
        FT_STRING, BASE_NONE, NULL, 0,
        NULL, HFILL }},
    { &hf_credssp_credBuffer,
      { "credBuffer", "credssp.credBuffer",
        FT_BYTES, BASE_NONE, NULL, 0,
        NULL, HFILL }},
    { &hf_credssp_logonCred,
      { "logonCred", "credssp.logonCred_element",
        FT_NONE, BASE_NONE, NULL, 0,
        "TSRemoteGuardPackageCred", HFILL }},
    { &hf_credssp_supplementalCreds,
      { "supplementalCreds", "credssp.supplementalCreds",
        FT_UINT32, BASE_DEC, NULL, 0,
        "SEQUENCE_OF_TSRemoteGuardPackageCred", HFILL }},
    { &hf_credssp_supplementalCreds_item,
      { "TSRemoteGuardPackageCred", "credssp.TSRemoteGuardPackageCred_element",
        FT_NONE, BASE_NONE, NULL, 0,
        NULL, HFILL }},
    { &hf_credssp_credType,
      { "credType", "credssp.credType",
        FT_INT32, BASE_DEC, NULL, 0,
        NULL, HFILL }},
    { &hf_credssp_credentials,
      { "credentials", "credssp.credentials",
        FT_BYTES, BASE_NONE, NULL, 0,
        NULL, HFILL }},
    { &hf_credssp_version,
      { "version", "credssp.version",
        FT_INT32, BASE_DEC, NULL, 0,
        NULL, HFILL }},
    { &hf_credssp_negoTokens,
      { "negoTokens", "credssp.negoTokens",
        FT_UINT32, BASE_DEC, NULL, 0,
        "NegoData", HFILL }},
    { &hf_credssp_authInfo,
      { "authInfo", "credssp.authInfo",
        FT_BYTES, BASE_NONE, NULL, 0,
        NULL, HFILL }},
    { &hf_credssp_pubKeyAuth,
      { "pubKeyAuth", "credssp.pubKeyAuth",
        FT_BYTES, BASE_NONE, NULL, 0,
        NULL, HFILL }},
    { &hf_credssp_errorCode,
      { "errorCode", "credssp.errorCode",
        FT_INT32, BASE_DEC, NULL, 0,
        NULL, HFILL }},
    { &hf_credssp_clientNonce,
      { "clientNonce", "credssp.clientNonce",
        FT_BYTES, BASE_NONE, NULL, 0,
        NULL, HFILL }},
  };

  /* List of subtrees */
  static gint *ett[] = {
    &ett_credssp,
    &ett_credssp_RGC_CredBuffer,
    &ett_credssp_NegoData,
    &ett_credssp_NegoData_item,
    &ett_credssp_TSPasswordCreds,
    &ett_credssp_TSCspDataDetail,
    &ett_credssp_TSSmartCardCreds,
    &ett_credssp_TSRemoteGuardPackageCred,
    &ett_credssp_TSRemoteGuardCreds,
    &ett_credssp_SEQUENCE_OF_TSRemoteGuardPackageCred,
    &ett_credssp_TSCredentials,
    &ett_credssp_TSRequest,
  };


  /* Register protocol */
  proto_credssp = proto_register_protocol(PNAME, PSNAME, PFNAME);
  register_dissector("credssp", dissect_credssp, proto_credssp);

  /* Register fields and subtrees */
  proto_register_field_array(proto_credssp, hf, array_length(hf));
  proto_register_subtree_array(ett, array_length(ett));

  /* heuristic dissectors for any premable e.g. CredSSP before RDP */
  credssp_heur_subdissector_list = register_heur_dissector_list("credssp", proto_credssp);

}


/*--- proto_reg_handoff_credssp --- */
void proto_reg_handoff_credssp(void) {

  gssapi_handle = find_dissector_add_dependency("gssapi", proto_credssp);
  gssapi_wrap_handle = find_dissector_add_dependency("gssapi_verf", proto_credssp);

  heur_dissector_add("tls", dissect_credssp_heur, "CredSSP over TLS", "credssp_tls", proto_credssp, HEURISTIC_ENABLE);
  heur_dissector_add("rdp", dissect_credssp_heur, "CredSSP in TPKT", "credssp_tpkt", proto_credssp, HEURISTIC_ENABLE);
  exported_pdu_tap = find_tap_id(EXPORT_PDU_TAP_NAME_LAYER_7);
}