1/*
2 * Copyright (c) 2004 - Michael Richardson <mcr@xelerance.com>
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that: (1) source code distributions
6 * retain the above copyright notice and this paragraph in its entirety, (2)
7 * distributions including binary code include the above copyright notice and
8 * this paragraph in its entirety in the documentation or other materials
9 * provided with the distribution, and (3) all advertising materials mentioning
10 * features or use of this software display the following acknowledgement:
11 * ``This product includes software developed by the University of California,
12 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
13 * the University nor the names of its contributors may be used to endorse
14 * or promote products derived from this software without specific prior
15 * written permission.
16 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
17 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
18 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
19 *
20 * Format and print EAP packets.
21 *
22 */
23
24#define NETDISSECT_REWORKED
25#ifdef HAVE_CONFIG_H
26#include "config.h"
27#endif
28
29#include <tcpdump-stdinc.h>
30
31#include "interface.h"
32#include "extract.h"
33
34#define	EAP_FRAME_TYPE_PACKET		0
35#define	EAP_FRAME_TYPE_START		1
36#define	EAP_FRAME_TYPE_LOGOFF		2
37#define	EAP_FRAME_TYPE_KEY		3
38#define	EAP_FRAME_TYPE_ENCAP_ASF_ALERT	4
39
40struct eap_frame_t {
41    unsigned char   version;
42    unsigned char   type;
43    unsigned char   length[2];
44};
45
46static const struct tok eap_frame_type_values[] = {
47    { EAP_FRAME_TYPE_PACKET,      	"EAP packet" },
48    { EAP_FRAME_TYPE_START,    		"EAPOL start" },
49    { EAP_FRAME_TYPE_LOGOFF,      	"EAPOL logoff" },
50    { EAP_FRAME_TYPE_KEY,      		"EAPOL key" },
51    { EAP_FRAME_TYPE_ENCAP_ASF_ALERT, 	"Encapsulated ASF alert" },
52    { 0, NULL}
53};
54
55/* RFC 3748 */
56struct eap_packet_t {
57    unsigned char	code;
58    unsigned char	id;
59    unsigned char	length[2];
60};
61
62#define		EAP_REQUEST	1
63#define		EAP_RESPONSE	2
64#define		EAP_SUCCESS	3
65#define		EAP_FAILURE	4
66
67static const struct tok eap_code_values[] = {
68    { EAP_REQUEST,	"Request" },
69    { EAP_RESPONSE,	"Response" },
70    { EAP_SUCCESS,	"Success" },
71    { EAP_FAILURE,	"Failure" },
72    { 0, NULL}
73};
74
75#define		EAP_TYPE_NO_PROPOSED	0
76#define		EAP_TYPE_IDENTITY	1
77#define		EAP_TYPE_NOTIFICATION	2
78#define		EAP_TYPE_NAK		3
79#define		EAP_TYPE_MD5_CHALLENGE	4
80#define		EAP_TYPE_OTP		5
81#define		EAP_TYPE_GTC		6
82#define		EAP_TYPE_TLS		13		/* RFC 2716 */
83#define		EAP_TYPE_SIM		18		/* RFC 4186 */
84#define		EAP_TYPE_TTLS		21		/* draft-funk-eap-ttls-v0-01.txt */
85#define		EAP_TYPE_AKA		23		/* RFC 4187 */
86#define		EAP_TYPE_FAST		43		/* RFC 4851 */
87#define		EAP_TYPE_EXPANDED_TYPES	254
88#define		EAP_TYPE_EXPERIMENTAL	255
89
90static const struct tok eap_type_values[] = {
91    { EAP_TYPE_NO_PROPOSED,	"No proposed" },
92    { EAP_TYPE_IDENTITY,	"Identity" },
93    { EAP_TYPE_NOTIFICATION,    "Notification" },
94    { EAP_TYPE_NAK,      	"Nak" },
95    { EAP_TYPE_MD5_CHALLENGE,   "MD5-challenge" },
96    { EAP_TYPE_OTP,      	"OTP" },
97    { EAP_TYPE_GTC,      	"GTC" },
98    { EAP_TYPE_TLS,      	"TLS" },
99    { EAP_TYPE_SIM,      	"SIM" },
100    { EAP_TYPE_TTLS,      	"TTLS" },
101    { EAP_TYPE_AKA,      	"AKA" },
102    { EAP_TYPE_FAST,      	"FAST" },
103    { EAP_TYPE_EXPANDED_TYPES,  "Expanded types" },
104    { EAP_TYPE_EXPERIMENTAL,    "Experimental" },
105    { 0, NULL}
106};
107
108#define EAP_TLS_EXTRACT_BIT_L(x) 	(((x)&0x80)>>7)
109
110/* RFC 2716 - EAP TLS bits */
111#define EAP_TLS_FLAGS_LEN_INCLUDED		(1 << 7)
112#define EAP_TLS_FLAGS_MORE_FRAGMENTS		(1 << 6)
113#define EAP_TLS_FLAGS_START			(1 << 5)
114
115static const struct tok eap_tls_flags_values[] = {
116	{ EAP_TLS_FLAGS_LEN_INCLUDED, "L bit" },
117	{ EAP_TLS_FLAGS_MORE_FRAGMENTS, "More fragments bit"},
118	{ EAP_TLS_FLAGS_START, "Start bit"},
119	{ 0, NULL}
120};
121
122#define EAP_TTLS_VERSION(x)		((x)&0x07)
123
124/* EAP-AKA and EAP-SIM - RFC 4187 */
125#define EAP_AKA_CHALLENGE		1
126#define EAP_AKA_AUTH_REJECT		2
127#define EAP_AKA_SYNC_FAILURE		4
128#define EAP_AKA_IDENTITY		5
129#define EAP_SIM_START			10
130#define EAP_SIM_CHALLENGE		11
131#define EAP_AKA_NOTIFICATION		12
132#define EAP_AKA_REAUTH			13
133#define EAP_AKA_CLIENT_ERROR		14
134
135static const struct tok eap_aka_subtype_values[] = {
136    { EAP_AKA_CHALLENGE,	"Challenge" },
137    { EAP_AKA_AUTH_REJECT,	"Auth reject" },
138    { EAP_AKA_SYNC_FAILURE,	"Sync failure" },
139    { EAP_AKA_IDENTITY,		"Identity" },
140    { EAP_SIM_START,		"Start" },
141    { EAP_SIM_CHALLENGE,	"Challenge" },
142    { EAP_AKA_NOTIFICATION,	"Notification" },
143    { EAP_AKA_REAUTH,		"Reauth" },
144    { EAP_AKA_CLIENT_ERROR,	"Client error" },
145    { 0, NULL}
146};
147
148/*
149 * Print EAP requests / responses
150 */
151void
152eap_print(netdissect_options *ndo,
153          register const u_char *cp,
154          u_int length _U_)
155{
156    const struct eap_frame_t *eap;
157    const u_char *tptr;
158    u_int tlen, type, subtype;
159    int count=0, len;
160
161    tptr = cp;
162    tlen = length;
163    eap = (const struct eap_frame_t *)cp;
164    ND_TCHECK(*eap);
165
166    /* in non-verbose mode just lets print the basic info */
167    if (ndo->ndo_vflag < 1) {
168	ND_PRINT((ndo, "%s (%u) v%u, len %u",
169               tok2str(eap_frame_type_values, "unknown", eap->type),
170               eap->type,
171               eap->version,
172               EXTRACT_16BITS(eap->length)));
173	return;
174    }
175
176    ND_PRINT((ndo, "%s (%u) v%u, len %u",
177           tok2str(eap_frame_type_values, "unknown", eap->type),
178           eap->type,
179           eap->version,
180           EXTRACT_16BITS(eap->length)));
181
182    tptr += sizeof(const struct eap_frame_t);
183    tlen -= sizeof(const struct eap_frame_t);
184
185    switch (eap->type) {
186    case EAP_FRAME_TYPE_PACKET:
187        type = *(tptr);
188        len = EXTRACT_16BITS(tptr+2);
189        ND_PRINT((ndo, ", %s (%u), id %u, len %u",
190               tok2str(eap_code_values, "unknown", type),
191               type,
192               *(tptr+1),
193               len));
194
195        ND_TCHECK2(*tptr, len);
196
197        if (type <= 2) { /* For EAP_REQUEST and EAP_RESPONSE only */
198            subtype = *(tptr+4);
199            ND_PRINT((ndo, "\n\t\t Type %s (%u)",
200                   tok2str(eap_type_values, "unknown", *(tptr+4)),
201                   *(tptr + 4)));
202
203            switch (subtype) {
204            case EAP_TYPE_IDENTITY:
205                if (len - 5 > 0) {
206                    ND_PRINT((ndo, ", Identity: "));
207                    safeputs(ndo, tptr + 5, len - 5);
208                }
209                break;
210
211            case EAP_TYPE_NOTIFICATION:
212                if (len - 5 > 0) {
213                    ND_PRINT((ndo, ", Notification: "));
214                    safeputs(ndo, tptr + 5, len - 5);
215                }
216                break;
217
218            case EAP_TYPE_NAK:
219                count = 5;
220
221                /*
222                 * one or more octets indicating
223                 * the desired authentication
224                 * type one octet per type
225                 */
226                while (count < len) {
227                    ND_PRINT((ndo, " %s (%u),",
228                           tok2str(eap_type_values, "unknown", *(tptr+count)),
229                           *(tptr + count)));
230                    count++;
231                }
232                break;
233
234            case EAP_TYPE_TTLS:
235                ND_PRINT((ndo, " TTLSv%u",
236                       EAP_TTLS_VERSION(*(tptr + 5)))); /* fall through */
237            case EAP_TYPE_TLS:
238                ND_PRINT((ndo, " flags [%s] 0x%02x,",
239                       bittok2str(eap_tls_flags_values, "none", *(tptr+5)),
240                       *(tptr + 5)));
241
242                if (EAP_TLS_EXTRACT_BIT_L(*(tptr+5))) {
243		    ND_PRINT((ndo, " len %u", EXTRACT_32BITS(tptr + 6)));
244                }
245                break;
246
247            case EAP_TYPE_FAST:
248                ND_PRINT((ndo, " FASTv%u",
249                       EAP_TTLS_VERSION(*(tptr + 5))));
250                ND_PRINT((ndo, " flags [%s] 0x%02x,",
251                       bittok2str(eap_tls_flags_values, "none", *(tptr+5)),
252                       *(tptr + 5)));
253
254                if (EAP_TLS_EXTRACT_BIT_L(*(tptr+5))) {
255                    ND_PRINT((ndo, " len %u", EXTRACT_32BITS(tptr + 6)));
256                }
257
258                /* FIXME - TLV attributes follow */
259                break;
260
261            case EAP_TYPE_AKA:
262            case EAP_TYPE_SIM:
263                ND_PRINT((ndo, " subtype [%s] 0x%02x,",
264                       tok2str(eap_aka_subtype_values, "unknown", *(tptr+5)),
265                       *(tptr + 5)));
266
267                /* FIXME - TLV attributes follow */
268                break;
269
270            case EAP_TYPE_MD5_CHALLENGE:
271            case EAP_TYPE_OTP:
272            case EAP_TYPE_GTC:
273            case EAP_TYPE_EXPANDED_TYPES:
274            case EAP_TYPE_EXPERIMENTAL:
275            default:
276                break;
277            }
278        }
279        break;
280
281    case EAP_FRAME_TYPE_LOGOFF:
282    case EAP_FRAME_TYPE_ENCAP_ASF_ALERT:
283    default:
284        break;
285    }
286    return;
287
288 trunc:
289    ND_PRINT((ndo, "\n\t[|EAP]"));
290}
291
292/*
293 * Local Variables:
294 * c-basic-offset: 4
295 * End:
296 */
297