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
40 struct eap_frame_t {
41 unsigned char version;
42 unsigned char type;
43 unsigned char length[2];
44 };
45
46 static 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 */
56 struct 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
67 static 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
90 static 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
115 static 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
135 static 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 */
151 void
eap_print(netdissect_options * ndo,register const u_char * cp,u_int length _U_)152 eap_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