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
|
/* packet-kerberos4.c
* Routines for Kerberos v4 packet dissection
*
* Ronnie Sahlberg 2004
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* Copyright 1998 Gerald Combs
*
* SPDX-License-Identifier: GPL-2.0-or-later
*/
/*
* PDU structure based on the document:
*
* Athena Technical Plan
* Section E.2.1
* Kerberos Authentication and Authorization System
* by S. P. Miller, B. C. Neuman, J. I. Schiller, and J. H. Saltzer
*
* http://web.mit.edu/Saltzer/www/publications/athenaplan/e.2.1.pdf
*
* 7. Appendix I Design Specifications
*/
#include "config.h"
#include <epan/packet.h>
void proto_register_krb4(void);
void proto_reg_handoff_krb4(void);
static int proto_krb4 = -1;
static int hf_krb4_version = -1;
static int hf_krb4_auth_msg_type = -1;
static int hf_krb4_m_type = -1;
static int hf_krb4_byte_order = -1;
static int hf_krb4_name = -1;
static int hf_krb4_instance = -1;
static int hf_krb4_realm = -1;
static int hf_krb4_time_sec = -1;
static int hf_krb4_exp_date = -1;
static int hf_krb4_req_date = -1;
static int hf_krb4_lifetime = -1;
static int hf_krb4_s_name = -1;
static int hf_krb4_s_instance = -1;
static int hf_krb4_kvno = -1;
static int hf_krb4_length = -1;
static int hf_krb4_ticket_length = -1;
static int hf_krb4_request_length = -1;
static int hf_krb4_ticket_blob = -1;
static int hf_krb4_request_blob = -1;
static int hf_krb4_encrypted_blob = -1;
static int hf_krb4_unknown_transarc_blob = -1;
static gint ett_krb4 = -1;
static gint ett_krb4_auth_msg_type = -1;
static dissector_handle_t krb4_handle;
#define UDP_PORT_KRB4 750
#define TRANSARC_SPECIAL_VERSION 0x63
static const value_string byte_order_vals[] = {
{ 0, "Big Endian" },
{ 1, "Little Endian" },
{ 0, NULL }
};
#define AUTH_MSG_KDC_REQUEST 1
#define AUTH_MSG_KDC_REPLY 2
#define AUTH_MSG_APPL_REQUEST 3
#define AUTH_MSG_APPL_REQUEST_MUTUAL 4
#define AUTH_MSG_ERR_REPLY 5
#define AUTH_MSG_PRIVATE 6
#define AUTH_MSG_SAFE 7
#define AUTH_MSG_APPL_ERR 8
#define AUTH_MSG_DIE 63
static const value_string m_type_vals[] = {
{ AUTH_MSG_KDC_REQUEST, "KDC Request" },
{ AUTH_MSG_KDC_REPLY, "KDC Reply" },
{ AUTH_MSG_APPL_REQUEST, "Appl Request" },
{ AUTH_MSG_APPL_REQUEST_MUTUAL, "Appl Request Mutual" },
{ AUTH_MSG_ERR_REPLY, "Err Reply" },
{ AUTH_MSG_PRIVATE, "Private" },
{ AUTH_MSG_SAFE, "Safe" },
{ AUTH_MSG_APPL_ERR, "Appl Err" },
{ AUTH_MSG_DIE, "Die" },
{ 0, NULL }
};
static int
dissect_krb4_string(packet_info *pinfo _U_, int hf_index, proto_tree *tree, tvbuff_t *tvb, int offset)
{
gint length;
proto_tree_add_item_ret_length(tree, hf_index, tvb, offset, -1, ENC_ASCII|ENC_NA, &length);
return offset + length;
}
static int
dissect_krb4_kdc_request(packet_info *pinfo, proto_tree *tree, tvbuff_t *tvb, int offset, const guint encoding, int version)
{
guint8 lifetime;
if(version==TRANSARC_SPECIAL_VERSION){
proto_tree_add_item(tree, hf_krb4_unknown_transarc_blob, tvb, offset, 8, ENC_NA);
offset+=8;
}
/* Name */
offset=dissect_krb4_string(pinfo, hf_krb4_name, tree, tvb, offset);
/* Instance */
offset=dissect_krb4_string(pinfo, hf_krb4_instance, tree, tvb, offset);
/* Realm */
offset=dissect_krb4_string(pinfo, hf_krb4_realm, tree, tvb, offset);
/* Time sec */
proto_tree_add_item(tree, hf_krb4_time_sec, tvb, offset, 4, ENC_TIME_SECS|encoding);
offset+=4;
/* lifetime */
lifetime=tvb_get_guint8(tvb, offset);
proto_tree_add_uint_format_value(tree, hf_krb4_lifetime, tvb, offset, 1, lifetime, "%d (%d minutes)", lifetime, lifetime*5);
offset++;
/* service Name */
offset=dissect_krb4_string(pinfo, hf_krb4_s_name, tree, tvb, offset);
/* service Instance */
offset=dissect_krb4_string(pinfo, hf_krb4_s_instance, tree, tvb, offset);
return offset;
}
static int
dissect_krb4_kdc_reply(packet_info *pinfo, proto_tree *tree, tvbuff_t *tvb, int offset, const guint encoding)
{
guint32 length;
/* Name */
offset=dissect_krb4_string(pinfo, hf_krb4_name, tree, tvb, offset);
/* Instance */
offset=dissect_krb4_string(pinfo, hf_krb4_instance, tree, tvb, offset);
/* Realm */
offset=dissect_krb4_string(pinfo, hf_krb4_realm, tree, tvb, offset);
/* Time sec */
proto_tree_add_item(tree, hf_krb4_time_sec, tvb, offset, 4, ENC_TIME_SECS|encoding);
offset+=4;
/*XXX unknown byte here */
offset++;
/* exp date */
proto_tree_add_item(tree, hf_krb4_exp_date, tvb, offset, 4, ENC_TIME_SECS|encoding);
offset+=4;
/* kvno */
proto_tree_add_item(tree, hf_krb4_kvno, tvb, offset, 1, ENC_BIG_ENDIAN);
offset++;
/* length2 */
proto_tree_add_item_ret_uint(tree, hf_krb4_length, tvb, offset, 2, encoding, &length);
offset+=2;
/* encrypted blob */
proto_tree_add_item(tree, hf_krb4_encrypted_blob, tvb, offset, length, ENC_NA);
offset+=length;
return offset;
}
static int
dissect_krb4_appl_request(packet_info *pinfo, proto_tree *tree, tvbuff_t *tvb, int offset, const guint encoding)
{
guint8 tlen, rlen;
guint8 lifetime;
/* kvno */
proto_tree_add_item(tree, hf_krb4_kvno, tvb, offset, 1, ENC_BIG_ENDIAN);
offset++;
/* Realm */
offset=dissect_krb4_string(pinfo, hf_krb4_realm, tree, tvb, offset);
/* ticket length */
tlen=tvb_get_guint8(tvb, offset);
proto_tree_add_item(tree, hf_krb4_ticket_length, tvb, offset, 1, ENC_BIG_ENDIAN);
offset++;
/* request length */
rlen=tvb_get_guint8(tvb, offset);
proto_tree_add_item(tree, hf_krb4_request_length, tvb, offset, 1, ENC_BIG_ENDIAN);
offset++;
/* ticket */
proto_tree_add_item(tree, hf_krb4_ticket_blob, tvb, offset, tlen, ENC_NA);
offset+=tlen;
/* request */
proto_tree_add_item(tree, hf_krb4_request_blob, tvb, offset, rlen, ENC_NA);
offset+=rlen;
/* request time */
proto_tree_add_item(tree, hf_krb4_req_date, tvb, offset, 4, ENC_TIME_SECS|encoding);
offset+=4;
/* lifetime */
lifetime=tvb_get_guint8(tvb, offset);
proto_tree_add_uint_format_value(tree, hf_krb4_lifetime, tvb, offset, 1, lifetime, "%d (%d minutes)", lifetime, lifetime*5);
offset++;
/* service Name */
offset=dissect_krb4_string(pinfo, hf_krb4_s_name, tree, tvb, offset);
/* service Instance */
offset=dissect_krb4_string(pinfo, hf_krb4_s_instance, tree, tvb, offset);
return offset;
}
static int
dissect_krb4_auth_msg_type(packet_info *pinfo, proto_tree *parent_tree, tvbuff_t *tvb, int offset, int version)
{
proto_tree *tree;
proto_item *item;
guint8 auth_msg_type;
auth_msg_type=tvb_get_guint8(tvb, offset);
item = proto_tree_add_item(parent_tree, hf_krb4_auth_msg_type, tvb, offset, 1, ENC_BIG_ENDIAN);
tree = proto_item_add_subtree(item, ett_krb4_auth_msg_type);
/* m_type */
proto_tree_add_item(tree, hf_krb4_m_type, tvb, offset, 1, ENC_BIG_ENDIAN);
col_append_fstr(pinfo->cinfo, COL_INFO, "%s%s",
(version==TRANSARC_SPECIAL_VERSION)?"TRANSARC-":"",
val_to_str(auth_msg_type>>1, m_type_vals, "Unknown (0x%04x)"));
proto_item_append_text(item, " %s%s",
(version==TRANSARC_SPECIAL_VERSION)?"TRANSARC-":"",
val_to_str(auth_msg_type>>1, m_type_vals, "Unknown (0x%04x)"));
/* byte order */
proto_tree_add_item(tree, hf_krb4_byte_order, tvb, offset, 1, ENC_BIG_ENDIAN);
proto_item_append_text(item, " (%s)", val_to_str(auth_msg_type&0x01, byte_order_vals, "Unknown (0x%04x)"));
offset++;
return offset;
}
static gboolean
dissect_krb4(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree, void *data _U_)
{
proto_tree *tree;
proto_item *item;
guint8 version, opcode;
int offset = 0;
guint encoding;
/* this should better have the value 4 or it might be a weirdo
* Transarc AFS special unknown thing.
*/
version=tvb_get_guint8(tvb, offset);
if((version!=4)&&(version!=TRANSARC_SPECIAL_VERSION)){
return FALSE;
}
opcode=tvb_get_guint8(tvb, offset+1);
switch(opcode>>1){
case AUTH_MSG_KDC_REQUEST:
case AUTH_MSG_KDC_REPLY:
case AUTH_MSG_APPL_REQUEST:
case AUTH_MSG_APPL_REQUEST_MUTUAL:
case AUTH_MSG_ERR_REPLY:
case AUTH_MSG_PRIVATE:
case AUTH_MSG_SAFE:
case AUTH_MSG_APPL_ERR:
case AUTH_MSG_DIE:
break;
default:
return FALSE;
}
/* create a tree for krb4 */
item = proto_tree_add_item(parent_tree, proto_krb4, tvb, offset, -1, ENC_NA);
tree = proto_item_add_subtree(item, ett_krb4);
col_set_str(pinfo->cinfo, COL_PROTOCOL, "KRB4");
col_clear(pinfo->cinfo, COL_INFO);
/* version */
proto_tree_add_item(tree, hf_krb4_version, tvb, offset, 1, ENC_BIG_ENDIAN);
offset++;
/* auth_msg_type */
offset = dissect_krb4_auth_msg_type(pinfo, tree, tvb, offset, version);
encoding = opcode&0x01 ? ENC_LITTLE_ENDIAN : ENC_BIG_ENDIAN;
switch(opcode>>1){
case AUTH_MSG_KDC_REQUEST:
dissect_krb4_kdc_request(pinfo, tree, tvb, offset, encoding, version);
break;
case AUTH_MSG_KDC_REPLY:
dissect_krb4_kdc_reply(pinfo, tree, tvb, offset, encoding);
break;
case AUTH_MSG_APPL_REQUEST:
dissect_krb4_appl_request(pinfo, tree, tvb, offset, encoding);
break;
case AUTH_MSG_APPL_REQUEST_MUTUAL:
case AUTH_MSG_ERR_REPLY:
case AUTH_MSG_PRIVATE:
case AUTH_MSG_SAFE:
case AUTH_MSG_APPL_ERR:
case AUTH_MSG_DIE:
break;
}
return TRUE;
}
void
proto_register_krb4(void)
{
static hf_register_info hf[] = {
{ &hf_krb4_version,
{ "Version", "krb4.version",
FT_UINT8, BASE_DEC, NULL, 0x0,
"Kerberos(v4) version number", HFILL }},
{ &hf_krb4_auth_msg_type,
{ "Msg Type", "krb4.auth_msg_type",
FT_UINT8, BASE_HEX, NULL, 0x0,
"Message Type/Byte Order", HFILL }},
{ &hf_krb4_m_type,
{ "M Type", "krb4.m_type",
FT_UINT8, BASE_HEX, VALS(m_type_vals), 0xfe,
"Message Type", HFILL }},
{ &hf_krb4_byte_order,
{ "Byte Order", "krb4.byte_order",
FT_UINT8, BASE_HEX, VALS(byte_order_vals), 0x01,
NULL, HFILL }},
{ &hf_krb4_name,
{ "Name", "krb4.name",
FT_STRINGZ, BASE_NONE, NULL, 0x00,
NULL, HFILL }},
{ &hf_krb4_instance,
{ "Instance", "krb4.instance",
FT_STRINGZ, BASE_NONE, NULL, 0x00,
NULL, HFILL }},
{ &hf_krb4_realm,
{ "Realm", "krb4.realm",
FT_STRINGZ, BASE_NONE, NULL, 0x00,
NULL, HFILL }},
{ &hf_krb4_time_sec,
{ "Time Sec", "krb4.time_sec",
FT_ABSOLUTE_TIME, ABSOLUTE_TIME_LOCAL, NULL, 0x00,
NULL, HFILL }},
{ &hf_krb4_exp_date,
{ "Exp Date", "krb4.exp_date",
FT_ABSOLUTE_TIME, ABSOLUTE_TIME_LOCAL, NULL, 0x00,
NULL, HFILL }},
{ &hf_krb4_req_date,
{ "Req Date", "krb4.req_date",
FT_ABSOLUTE_TIME, ABSOLUTE_TIME_LOCAL, NULL, 0x00,
NULL, HFILL }},
{ &hf_krb4_lifetime,
{ "Lifetime", "krb4.lifetime",
FT_UINT8, BASE_DEC, NULL, 0x00,
"Lifetime (in 5 min units)", HFILL }},
{ &hf_krb4_s_name,
{ "Service Name", "krb4.s_name",
FT_STRINGZ, BASE_NONE, NULL, 0x00,
NULL, HFILL }},
{ &hf_krb4_s_instance,
{ "Service Instance", "krb4.s_instance",
FT_STRINGZ, BASE_NONE, NULL, 0x00,
NULL, HFILL }},
{ &hf_krb4_kvno,
{ "Kvno", "krb4.kvno",
FT_UINT8, BASE_DEC, NULL, 0x00,
"Key Version No", HFILL }},
{ &hf_krb4_length,
{ "Length", "krb4.length",
FT_UINT32, BASE_DEC, NULL, 0x00,
"Length of encrypted blob", HFILL }},
{ &hf_krb4_ticket_length,
{ "Ticket Length", "krb4.ticket.length",
FT_UINT8, BASE_DEC, NULL, 0x00,
"Length of ticket", HFILL }},
{ &hf_krb4_request_length,
{ "Request Length", "krb4.request.length",
FT_UINT8, BASE_DEC, NULL, 0x00,
"Length of request", HFILL }},
{ &hf_krb4_ticket_blob,
{ "Ticket Blob", "krb4.ticket.blob",
FT_BYTES, BASE_NONE, NULL, 0x00,
NULL, HFILL }},
{ &hf_krb4_request_blob,
{ "Request Blob", "krb4.request.blob",
FT_BYTES, BASE_NONE, NULL, 0x00,
NULL, HFILL }},
{ &hf_krb4_encrypted_blob,
{ "Encrypted Blob", "krb4.encrypted_blob",
FT_BYTES, BASE_NONE, NULL, 0x00,
NULL, HFILL }},
{ &hf_krb4_unknown_transarc_blob,
{ "Unknown Transarc Blob", "krb4.unknown_transarc_blob",
FT_BYTES, BASE_NONE, NULL, 0x00,
"Unknown blob only present in Transarc packets", HFILL }},
};
static gint *ett[] = {
&ett_krb4,
&ett_krb4_auth_msg_type,
};
proto_krb4 = proto_register_protocol("Kerberos v4",
"KRB4", "krb4");
krb4_handle = register_dissector("krb4", dissect_krb4, proto_krb4);
proto_register_field_array(proto_krb4, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
}
void
proto_reg_handoff_krb4(void)
{
dissector_add_uint_with_preference("udp.port", UDP_PORT_KRB4, krb4_handle);
}
/*
* Editor modelines - https://www.wireshark.org/tools/modelines.html
*
* Local variables:
* c-basic-offset: 8
* tab-width: 8
* indent-tabs-mode: t
* End:
*
* vi: set shiftwidth=8 tabstop=8 noexpandtab:
* :indentSize=8:tabSize=8:noTabs=false:
*/
|
