aboutsummaryrefslogtreecommitdiffstats
path: root/packet-eapol.c
blob: 5fe09ff0d29dcc5fffa4fca41aff13f046289338 (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
/* packet-eapol.c
 * Routines for EAPOL 802.1X authentication header disassembly
 * (From IEEE Draft P802.1X/D11; is there a later draft, or a
 * final standard?  If so, check it.)
 *
 * $Id: packet-eapol.c,v 1.19 2004/04/07 06:04:22 guy Exp $
 *
 * Ethereal - Network traffic analyzer
 * By Gerald Combs <gerald@ethereal.com>
 * Copyright 1998 Gerald Combs
 *
 * 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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */

#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

#include <glib.h>
#include <epan/packet.h>
#include "packet-ieee80211.h"
#include "etypes.h"

static int proto_eapol = -1;
static int hf_eapol_version = -1;
static int hf_eapol_type = -1;
static int hf_eapol_len = -1;
static int hf_eapol_keydes_type = -1;
static int hf_eapol_keydes_keylen = -1;
static int hf_eapol_keydes_replay_counter = -1;
static int hf_eapol_keydes_key_iv = -1;
static int hf_eapol_keydes_key_index_keytype = -1;
static int hf_eapol_keydes_key_index_indexnum = -1;
static int hf_eapol_keydes_key_signature = -1;
static int hf_eapol_keydes_key = -1;

static int hf_eapol_wpa_keydes_keyinfo = -1;
static int hf_eapol_wpa_keydes_keyinfo_keydes_ver = -1;
static int hf_eapol_wpa_keydes_keyinfo_key_type = -1;
static int hf_eapol_wpa_keydes_keyinfo_key_index = -1;
static int hf_eapol_wpa_keydes_keyinfo_install = -1;
static int hf_eapol_wpa_keydes_keyinfo_key_ack = -1;
static int hf_eapol_wpa_keydes_keyinfo_key_mic = -1;
static int hf_eapol_wpa_keydes_keyinfo_secure = -1;
static int hf_eapol_wpa_keydes_keyinfo_error = -1;
static int hf_eapol_wpa_keydes_keyinfo_request = -1;
static int hf_eapol_wpa_keydes_keyinfo_encr_key_data = -1;
static int hf_eapol_wpa_keydes_nonce = -1;
static int hf_eapol_wpa_keydes_rsc = -1;
static int hf_eapol_wpa_keydes_id = -1;
static int hf_eapol_wpa_keydes_mic = -1;
static int hf_eapol_wpa_keydes_datalen = -1;
static int hf_eapol_wpa_keydes_data = -1;

static gint ett_eapol = -1;
static gint ett_eapol_keydes_data = -1;
static gint ett_eapol_key_index = -1;
static gint ett_keyinfo = -1;

static dissector_handle_t eap_handle;
static dissector_handle_t data_handle;

#define EAPOL_HDR_LEN	4

#define EAP_PACKET		0
#define EAPOL_START		1
#define EAPOL_LOGOFF		2
#define EAPOL_KEY		3
#define EAPOL_ENCAP_ASF_ALERT	4

#define EAPOL_RSN_KEY		2 /* TBD, may change in final IEEE 802.1X-REV
				   */
#define EAPOL_WPA_KEY		254

static const value_string eapol_type_vals[] = {
    { EAP_PACKET,            "EAP Packet" },
    { EAPOL_START,           "Start" },
    { EAPOL_LOGOFF,          "Logoff" },
    { EAPOL_KEY,             "Key" },
    { EAPOL_ENCAP_ASF_ALERT, "Encapsulated ASF Alert" },
    { 0,                     NULL }
};

static const value_string eapol_keydes_type_vals[] = {
	{ 1, "RC4 Descriptor" },
	{ EAPOL_RSN_KEY, "EAPOL RSN key" },
	{ EAPOL_WPA_KEY, "EAPOL WPA key" },
	{ 0, NULL }
};

#define KEY_INFO_KEYDES_VER_MASK	0x0007
#define KEY_INFO_KEY_TYPE_MASK		0x0008
#define KEY_INFO_KEY_INDEX_MASK		0x0030
#define KEY_INFO_INSTALL_MASK		0x0040
#define KEY_INFO_KEY_ACK_MASK		0x0080
#define KEY_INFO_KEY_MIC_MASK		0x0100
#define KEY_INFO_SECURE_MASK		0x0200
#define KEY_INFO_ERROR_MASK		0x0400
#define KEY_INFO_REQUEST_MASK		0x0800
#define KEY_INFO_ENCR_KEY_DATA_MASK	0x1000

static const true_false_string keytype_tfs =
	{ "Unicast", "Broadcast" };
static const true_false_string tfs_keyinfo_key_type =
	{ "Pairwise key", "Group key" };
#define KEYDES_VER_TYPE1	0x01
#define KEYDES_VER_TYPE2	0x02
static const value_string keydes_ver[] = {
	{ KEYDES_VER_TYPE1,	"HMAC-MD5 for MIC and RC4 for encryption" },
	{ KEYDES_VER_TYPE2,	"AES-CBC-MAC for MIC and HMAC-SHA1 for encryption" },
	{ 0, 		NULL }
};

static void
dissect_eapol(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
  int         offset = 0;
  guint8      eapol_type;
  guint8      keydesc_type;
  guint16     eapol_len;
  guint       len;
  guint16     eapol_key_len, eapol_data_len;
  guint8      key_index;
  guint16     keyinfo;
  proto_tree *ti = NULL;
  proto_tree *eapol_tree = NULL;
  proto_tree *keyinfo_item = NULL;
  proto_tree *keyinfo_tree = NULL;
  proto_tree *key_index_tree, *keydes_tree;
  tvbuff_t   *next_tvb;

  if (check_col(pinfo->cinfo, COL_PROTOCOL))
    col_set_str(pinfo->cinfo, COL_PROTOCOL, "EAPOL");
  if (check_col(pinfo->cinfo, COL_INFO))
    col_clear(pinfo->cinfo, COL_INFO);

  if (tree) {
    ti = proto_tree_add_item(tree, proto_eapol, tvb, 0, -1, FALSE);
    eapol_tree = proto_item_add_subtree(ti, ett_eapol);

    proto_tree_add_item(eapol_tree, hf_eapol_version, tvb, offset, 1, FALSE);
  }
  offset++;

  eapol_type = tvb_get_guint8(tvb, offset);
  if (tree)
    proto_tree_add_uint(eapol_tree, hf_eapol_type, tvb, offset, 1, eapol_type);
  if (check_col(pinfo->cinfo, COL_INFO))
    col_add_str(pinfo->cinfo, COL_INFO,
		val_to_str(eapol_type, eapol_type_vals, "Unknown type (0x%02X)"));
  offset++;

  eapol_len = tvb_get_ntohs(tvb, offset);
  len = EAPOL_HDR_LEN + eapol_len;
  set_actual_length(tvb, len);
  if (tree) {
    proto_item_set_len(ti, len);
    proto_tree_add_uint(eapol_tree, hf_eapol_len, tvb, offset, 2, eapol_len);
  }
  offset += 2;

  switch (eapol_type) {

  case EAP_PACKET:
    next_tvb = tvb_new_subset(tvb, offset, -1, -1);
    call_dissector(eap_handle, next_tvb, pinfo, eapol_tree);
    break;

  case EAPOL_KEY:
    if (tree) {
      keydesc_type = tvb_get_guint8(tvb, offset);
      proto_tree_add_item(eapol_tree, hf_eapol_keydes_type, tvb, offset, 1, FALSE);
      offset += 1;
      if (keydesc_type == EAPOL_WPA_KEY || keydesc_type == EAPOL_RSN_KEY) {
	keyinfo = tvb_get_ntohs(tvb, offset);
	keyinfo_item = 
	  proto_tree_add_uint(eapol_tree, hf_eapol_wpa_keydes_keyinfo, tvb,
			      offset, 2, keyinfo);

	keyinfo_tree = proto_item_add_subtree(keyinfo_item, ett_keyinfo);
	proto_tree_add_uint(keyinfo_tree, hf_eapol_wpa_keydes_keyinfo_keydes_ver, tvb, offset, 2, keyinfo);
	proto_tree_add_boolean(keyinfo_tree, hf_eapol_wpa_keydes_keyinfo_key_type, tvb, offset, 2, keyinfo);
	proto_tree_add_uint(keyinfo_tree, hf_eapol_wpa_keydes_keyinfo_key_index, tvb, offset, 2, keyinfo);
	proto_tree_add_boolean(keyinfo_tree, hf_eapol_wpa_keydes_keyinfo_install, tvb, offset, 2, keyinfo);
	proto_tree_add_boolean(keyinfo_tree, hf_eapol_wpa_keydes_keyinfo_key_ack, tvb, offset, 2, keyinfo);
	proto_tree_add_boolean(keyinfo_tree, hf_eapol_wpa_keydes_keyinfo_key_mic, tvb, offset, 2, keyinfo);
	proto_tree_add_boolean(keyinfo_tree, hf_eapol_wpa_keydes_keyinfo_secure, tvb, offset, 2, keyinfo);
	proto_tree_add_boolean(keyinfo_tree, hf_eapol_wpa_keydes_keyinfo_error, tvb, offset, 2, keyinfo);
	proto_tree_add_boolean(keyinfo_tree, hf_eapol_wpa_keydes_keyinfo_request, tvb, offset, 2, keyinfo);
	proto_tree_add_boolean(keyinfo_tree, hf_eapol_wpa_keydes_keyinfo_encr_key_data, tvb, offset, 2, keyinfo);

        offset += 2;
        proto_tree_add_uint(eapol_tree, hf_eapol_keydes_keylen, tvb, offset,
        		    2, tvb_get_ntohs(tvb, offset));
        offset += 2;
        proto_tree_add_item(eapol_tree, hf_eapol_keydes_replay_counter, tvb,
        		    offset, 8, FALSE);
        offset += 8;
        proto_tree_add_item(eapol_tree, hf_eapol_wpa_keydes_nonce, tvb, offset,
        		    32, FALSE);
        offset += 32;
        proto_tree_add_item(eapol_tree, hf_eapol_keydes_key_iv, tvb,
        		    offset, 16, FALSE);
        offset += 16;
        proto_tree_add_item(eapol_tree, hf_eapol_wpa_keydes_rsc, tvb, offset,
        		    8, FALSE);
        offset += 8;
        proto_tree_add_item(eapol_tree, hf_eapol_wpa_keydes_id, tvb, offset, 8,
        		    FALSE);
        offset += 8;
        proto_tree_add_item(eapol_tree, hf_eapol_wpa_keydes_mic, tvb, offset,
        		    16, FALSE);
        offset += 16;
        eapol_data_len = tvb_get_ntohs(tvb, offset);
        proto_tree_add_uint(eapol_tree, hf_eapol_wpa_keydes_datalen, tvb,
        		    offset, 2, eapol_data_len);
        offset += 2;
        if (eapol_data_len != 0) {
          ti = proto_tree_add_item(eapol_tree, hf_eapol_wpa_keydes_data,
          	tvb, offset, eapol_data_len, FALSE);
	  if ((keyinfo & KEY_INFO_ENCR_KEY_DATA_MASK) ||
	      !(keyinfo & KEY_INFO_KEY_TYPE_MASK)) {
	    /* RSN: EAPOL-Key Key Data is encrypted.
	     * WPA: Group Keys use encrypted Key Data.
	     * Cannot parse this without knowing the key. */
	  } else {
	    keydes_tree = proto_item_add_subtree(ti, ett_eapol_keydes_data);
	    ieee_80211_add_tagged_parameters(tvb, offset, keydes_tree,
					     eapol_data_len);
	  }
        }
      }
      else {
        eapol_key_len = tvb_get_ntohs(tvb, offset);
        proto_tree_add_uint(eapol_tree, hf_eapol_keydes_keylen, tvb, offset, 2, eapol_key_len);
        offset += 2;
        proto_tree_add_item(eapol_tree, hf_eapol_keydes_replay_counter, tvb,
  			  offset, 8, FALSE);
        offset += 8;
        proto_tree_add_item(eapol_tree, hf_eapol_keydes_key_iv, tvb,
  			  offset, 16, FALSE);
        offset += 16;
        key_index = tvb_get_guint8(tvb, offset);
        ti = proto_tree_add_text(eapol_tree, tvb, offset, 1,
  			       "Key Index: %s, index %u",
  			       (key_index & 0x80) ? "unicast" : "broadcast",
  			       key_index & 0x7F);
        key_index_tree = proto_item_add_subtree(ti, ett_eapol_key_index);
        proto_tree_add_boolean(eapol_tree, hf_eapol_keydes_key_index_keytype,
  			     tvb, offset, 1, key_index);
        proto_tree_add_uint(eapol_tree, hf_eapol_keydes_key_index_indexnum,
  			     tvb, offset, 1, key_index);
        offset += 1;
        proto_tree_add_item(eapol_tree, hf_eapol_keydes_key_signature, tvb,
  			  offset, 16, FALSE);
        offset += 16;
        if (eapol_key_len != 0)
          proto_tree_add_item(eapol_tree, hf_eapol_keydes_key, tvb, offset,
  			    eapol_key_len, FALSE);
      }
    }
    break;

  case EAPOL_ENCAP_ASF_ALERT:	/* XXX - is this an SNMP trap? */
  default:
    next_tvb = tvb_new_subset(tvb, offset, -1, -1);
    call_dissector(data_handle, next_tvb, pinfo, eapol_tree);
    break;
  }
}

void
proto_register_eapol(void)
{
  static hf_register_info hf[] = {
	{ &hf_eapol_version, {
		"Version", "eapol.version", FT_UINT8, BASE_DEC,
		NULL, 0x0, "", HFILL }},
	{ &hf_eapol_type, {
		"Type", "eapol.type", FT_UINT8, BASE_DEC,
		VALS(eapol_type_vals), 0x0, "", HFILL }},
	{ &hf_eapol_len, {
		"Length", "eapol.len", FT_UINT16, BASE_DEC,
		NULL, 0x0, "Length", HFILL }},
	{ &hf_eapol_keydes_type, {
		"Descriptor Type", "eapol.keydes.type", FT_UINT8, BASE_DEC,
		VALS(eapol_keydes_type_vals), 0x0, "Key Descriptor Type", HFILL }},
	{ &hf_eapol_keydes_keylen, {
		"Key Length", "eapol.keydes.keylen", FT_UINT16, BASE_DEC,
		NULL, 0x0, "Key Length", HFILL }},
	{ &hf_eapol_keydes_replay_counter, {
		"Replay Counter", "eapol.keydes.replay_counter", FT_UINT64, BASE_DEC,
		NULL, 0x0, "Replay Counter", HFILL }},
	{ &hf_eapol_keydes_key_iv, {
		"Key IV", "eapol.keydes.key_iv", FT_BYTES, BASE_NONE,
		NULL, 0x0, "Key Initialization Vector", HFILL }},
	{ &hf_eapol_keydes_key_index_keytype, {
		"Key Type", "eapol.keydes.index.keytype", FT_BOOLEAN, 8,
		TFS(&keytype_tfs), 0x80, "Key Type (unicast/broadcast)", HFILL }},
	{ &hf_eapol_keydes_key_index_indexnum, {
		"Index Number", "eapol.keydes.index.indexnum", FT_UINT8, BASE_DEC,
		NULL, 0x7F, "Key Index number", HFILL }},
	{ &hf_eapol_keydes_key_signature, {
		"Key Signature", "eapol.keydes.key_signature", FT_BYTES, BASE_NONE,
		NULL, 0x0, "Key Signature", HFILL }},
	{ &hf_eapol_keydes_key, {
		"Key", "eapol.keydes.key", FT_BYTES, BASE_NONE,
		NULL, 0x0, "Key", HFILL }},

	{ &hf_eapol_wpa_keydes_keyinfo, {
		"Key Information", "eapol.keydes.key_info", FT_UINT16,
		BASE_HEX, NULL, 0x0, "WPA key info", HFILL }},

	{ &hf_eapol_wpa_keydes_keyinfo_keydes_ver, {
		"Key Descriptor Version", 
		"eapol.keydes.key_info.keydes_ver", 
		FT_UINT16, BASE_DEC, VALS(&keydes_ver),
		KEY_INFO_KEYDES_VER_MASK, 
		"Key Descriptor Version Type", HFILL }},
	{ &hf_eapol_wpa_keydes_keyinfo_key_type, {
		"Key Type", 
		"eapol.keydes.key_info.key_type", 
		FT_BOOLEAN, 16, TFS(&tfs_keyinfo_key_type), 
		KEY_INFO_KEY_TYPE_MASK, 
		"Key Type (Pairwise or Group)", HFILL }},
	{ &hf_eapol_wpa_keydes_keyinfo_key_index, {
		"Key Index", 
		"eapol.keydes.key_info.key_index", 
		FT_UINT16, BASE_DEC, NULL, 
		KEY_INFO_KEY_INDEX_MASK, 
		"Key Index (0-3) (RSN: Reserved)", HFILL }},
	{ &hf_eapol_wpa_keydes_keyinfo_install, {
		"Install flag", 
		"eapol.keydes.key_info.install", 
		FT_BOOLEAN, 16, TFS(&flags_set_truth), 
		KEY_INFO_INSTALL_MASK, 
		"Install flag", HFILL }},
	{ &hf_eapol_wpa_keydes_keyinfo_key_ack, {
		"Key Ack flag", 
		"eapol.keydes.key_info.key_ack", 
		FT_BOOLEAN, 16, TFS(&flags_set_truth), 
		KEY_INFO_KEY_ACK_MASK, 
		"Key Ack flag", HFILL }},
	{ &hf_eapol_wpa_keydes_keyinfo_key_mic, {
		"Key MIC flag", 
		"eapol.keydes.key_info.key_mic", 
		FT_BOOLEAN, 16, TFS(&flags_set_truth), 
		KEY_INFO_KEY_MIC_MASK, 
		"Key MIC flag", HFILL }},
	{ &hf_eapol_wpa_keydes_keyinfo_secure, {
		"Secure flag", 
		"eapol.keydes.key_info.secure", 
		FT_BOOLEAN, 16, TFS(&flags_set_truth), 
		KEY_INFO_SECURE_MASK, 
		"Secure flag", HFILL }},
	{ &hf_eapol_wpa_keydes_keyinfo_error, {
		"Error flag", 
		"eapol.keydes.key_info.error", 
		FT_BOOLEAN, 16, TFS(&flags_set_truth), 
		KEY_INFO_ERROR_MASK, 
		"Error flag", HFILL }},
	{ &hf_eapol_wpa_keydes_keyinfo_request, {
		"Request flag", 
		"eapol.keydes.key_info.request", 
		FT_BOOLEAN, 16, TFS(&flags_set_truth), 
		KEY_INFO_REQUEST_MASK, 
		"Request flag", HFILL }},
	{ &hf_eapol_wpa_keydes_keyinfo_encr_key_data, {
		"Encrypted Key Data flag", 
		"eapol.keydes.key_info.encr_key_data", 
		FT_BOOLEAN, 16, TFS(&flags_set_truth), 
		KEY_INFO_ENCR_KEY_DATA_MASK, 
		"Encrypted Key Data flag", HFILL }},
	{ &hf_eapol_wpa_keydes_nonce, {
		"Nonce", "eapol.keydes.nonce", FT_BYTES, BASE_NONE,
		NULL, 0x0, "WPA Key Nonce", HFILL }},
	{ &hf_eapol_wpa_keydes_rsc, {
		"WPA Key RSC", "eapol.keydes.rsc", FT_BYTES, BASE_NONE, NULL,
		0x0, "WPA Key Receive Sequence Counter", HFILL }},
	{ &hf_eapol_wpa_keydes_id, {
		"WPA Key ID", "eapol.keydes.id", FT_BYTES, BASE_NONE, NULL,
		0x0, "WPA Key ID(RSN Reserved)", HFILL }},
	{ &hf_eapol_wpa_keydes_mic, {
		"WPA Key MIC", "eapol.keydes.mic", FT_BYTES, BASE_NONE, NULL,
		0x0, "WPA Key Message Integrity Check", HFILL }},
	{ &hf_eapol_wpa_keydes_datalen, {
		"WPA Key Length", "eapol.keydes.datalen", FT_UINT16, BASE_DEC,
		NULL, 0x0, "WPA Key Data Length", HFILL }},
	{ &hf_eapol_wpa_keydes_data, {
		"WPA Key", "eapol.keydes.data", FT_BYTES, BASE_NONE,
		NULL, 0x0, "WPA Key Data", HFILL }},
  };
  static gint *ett[] = {
	&ett_eapol,
	&ett_eapol_keydes_data,
	&ett_keyinfo,
	&ett_eapol_key_index
  };

  proto_eapol = proto_register_protocol("802.1x Authentication", "EAPOL", "eapol");
  proto_register_field_array(proto_eapol, hf, array_length(hf));
  proto_register_subtree_array(ett, array_length(ett));
}

void
proto_reg_handoff_eapol(void)
{
  dissector_handle_t eapol_handle;

  /*
   * Get handles for the EAP and raw data dissectors.
   */
  eap_handle = find_dissector("eap");
  data_handle = find_dissector("data");

  eapol_handle = create_dissector_handle(dissect_eapol, proto_eapol);
  dissector_add("ethertype", ETHERTYPE_EAPOL, eapol_handle);
  dissector_add("ethertype", ETHERTYPE_RSN_PREAUTH, eapol_handle);
}