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
21 /* \summary: Extensible Authentication Protocol (EAP) printer */
22
23 #ifdef HAVE_CONFIG_H
24 #include "config.h"
25 #endif
26
27 #include <netdissect-stdinc.h>
28
29 #include "netdissect.h"
30 #include "extract.h"
31
32 #define EAP_FRAME_TYPE_PACKET 0
33 #define EAP_FRAME_TYPE_START 1
34 #define EAP_FRAME_TYPE_LOGOFF 2
35 #define EAP_FRAME_TYPE_KEY 3
36 #define EAP_FRAME_TYPE_ENCAP_ASF_ALERT 4
37
38 struct eap_frame_t {
39 unsigned char version;
40 unsigned char type;
41 unsigned char length[2];
42 };
43
44 static const struct tok eap_frame_type_values[] = {
45 { EAP_FRAME_TYPE_PACKET, "EAP packet" },
46 { EAP_FRAME_TYPE_START, "EAPOL start" },
47 { EAP_FRAME_TYPE_LOGOFF, "EAPOL logoff" },
48 { EAP_FRAME_TYPE_KEY, "EAPOL key" },
49 { EAP_FRAME_TYPE_ENCAP_ASF_ALERT, "Encapsulated ASF alert" },
50 { 0, NULL}
51 };
52
53 /* RFC 3748 */
54 struct eap_packet_t {
55 unsigned char code;
56 unsigned char id;
57 unsigned char length[2];
58 };
59
60 #define EAP_REQUEST 1
61 #define EAP_RESPONSE 2
62 #define EAP_SUCCESS 3
63 #define EAP_FAILURE 4
64
65 static const struct tok eap_code_values[] = {
66 { EAP_REQUEST, "Request" },
67 { EAP_RESPONSE, "Response" },
68 { EAP_SUCCESS, "Success" },
69 { EAP_FAILURE, "Failure" },
70 { 0, NULL}
71 };
72
73 #define EAP_TYPE_NO_PROPOSED 0
74 #define EAP_TYPE_IDENTITY 1
75 #define EAP_TYPE_NOTIFICATION 2
76 #define EAP_TYPE_NAK 3
77 #define EAP_TYPE_MD5_CHALLENGE 4
78 #define EAP_TYPE_OTP 5
79 #define EAP_TYPE_GTC 6
80 #define EAP_TYPE_TLS 13 /* RFC 2716 */
81 #define EAP_TYPE_SIM 18 /* RFC 4186 */
82 #define EAP_TYPE_TTLS 21 /* draft-funk-eap-ttls-v0-01.txt */
83 #define EAP_TYPE_AKA 23 /* RFC 4187 */
84 #define EAP_TYPE_FAST 43 /* RFC 4851 */
85 #define EAP_TYPE_EXPANDED_TYPES 254
86 #define EAP_TYPE_EXPERIMENTAL 255
87
88 static const struct tok eap_type_values[] = {
89 { EAP_TYPE_NO_PROPOSED, "No proposed" },
90 { EAP_TYPE_IDENTITY, "Identity" },
91 { EAP_TYPE_NOTIFICATION, "Notification" },
92 { EAP_TYPE_NAK, "Nak" },
93 { EAP_TYPE_MD5_CHALLENGE, "MD5-challenge" },
94 { EAP_TYPE_OTP, "OTP" },
95 { EAP_TYPE_GTC, "GTC" },
96 { EAP_TYPE_TLS, "TLS" },
97 { EAP_TYPE_SIM, "SIM" },
98 { EAP_TYPE_TTLS, "TTLS" },
99 { EAP_TYPE_AKA, "AKA" },
100 { EAP_TYPE_FAST, "FAST" },
101 { EAP_TYPE_EXPANDED_TYPES, "Expanded types" },
102 { EAP_TYPE_EXPERIMENTAL, "Experimental" },
103 { 0, NULL}
104 };
105
106 #define EAP_TLS_EXTRACT_BIT_L(x) (((x)&0x80)>>7)
107
108 /* RFC 2716 - EAP TLS bits */
109 #define EAP_TLS_FLAGS_LEN_INCLUDED (1 << 7)
110 #define EAP_TLS_FLAGS_MORE_FRAGMENTS (1 << 6)
111 #define EAP_TLS_FLAGS_START (1 << 5)
112
113 static const struct tok eap_tls_flags_values[] = {
114 { EAP_TLS_FLAGS_LEN_INCLUDED, "L bit" },
115 { EAP_TLS_FLAGS_MORE_FRAGMENTS, "More fragments bit"},
116 { EAP_TLS_FLAGS_START, "Start bit"},
117 { 0, NULL}
118 };
119
120 #define EAP_TTLS_VERSION(x) ((x)&0x07)
121
122 /* EAP-AKA and EAP-SIM - RFC 4187 */
123 #define EAP_AKA_CHALLENGE 1
124 #define EAP_AKA_AUTH_REJECT 2
125 #define EAP_AKA_SYNC_FAILURE 4
126 #define EAP_AKA_IDENTITY 5
127 #define EAP_SIM_START 10
128 #define EAP_SIM_CHALLENGE 11
129 #define EAP_AKA_NOTIFICATION 12
130 #define EAP_AKA_REAUTH 13
131 #define EAP_AKA_CLIENT_ERROR 14
132
133 static const struct tok eap_aka_subtype_values[] = {
134 { EAP_AKA_CHALLENGE, "Challenge" },
135 { EAP_AKA_AUTH_REJECT, "Auth reject" },
136 { EAP_AKA_SYNC_FAILURE, "Sync failure" },
137 { EAP_AKA_IDENTITY, "Identity" },
138 { EAP_SIM_START, "Start" },
139 { EAP_SIM_CHALLENGE, "Challenge" },
140 { EAP_AKA_NOTIFICATION, "Notification" },
141 { EAP_AKA_REAUTH, "Reauth" },
142 { EAP_AKA_CLIENT_ERROR, "Client error" },
143 { 0, NULL}
144 };
145
146 /*
147 * Print EAP requests / responses
148 */
149 void
eap_print(netdissect_options * ndo,register const u_char * cp,u_int length)150 eap_print(netdissect_options *ndo,
151 register const u_char *cp,
152 u_int length)
153 {
154 const struct eap_frame_t *eap;
155 const u_char *tptr;
156 u_int tlen, type, subtype;
157 int count=0, len;
158
159 tptr = cp;
160 tlen = length;
161 eap = (const struct eap_frame_t *)cp;
162 ND_TCHECK(*eap);
163
164 /* in non-verbose mode just lets print the basic info */
165 if (ndo->ndo_vflag < 1) {
166 ND_PRINT((ndo, "%s (%u) v%u, len %u",
167 tok2str(eap_frame_type_values, "unknown", eap->type),
168 eap->type,
169 eap->version,
170 EXTRACT_16BITS(eap->length)));
171 return;
172 }
173
174 ND_PRINT((ndo, "%s (%u) v%u, len %u",
175 tok2str(eap_frame_type_values, "unknown", eap->type),
176 eap->type,
177 eap->version,
178 EXTRACT_16BITS(eap->length)));
179
180 tptr += sizeof(const struct eap_frame_t);
181 tlen -= sizeof(const struct eap_frame_t);
182
183 switch (eap->type) {
184 case EAP_FRAME_TYPE_PACKET:
185 ND_TCHECK_8BITS(tptr);
186 type = *(tptr);
187 ND_TCHECK_16BITS(tptr+2);
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 ND_TCHECK_8BITS(tptr+4);
199 subtype = *(tptr+4);
200 ND_PRINT((ndo, "\n\t\t Type %s (%u)",
201 tok2str(eap_type_values, "unknown", subtype),
202 subtype));
203
204 switch (subtype) {
205 case EAP_TYPE_IDENTITY:
206 if (len - 5 > 0) {
207 ND_PRINT((ndo, ", Identity: "));
208 safeputs(ndo, tptr + 5, len - 5);
209 }
210 break;
211
212 case EAP_TYPE_NOTIFICATION:
213 if (len - 5 > 0) {
214 ND_PRINT((ndo, ", Notification: "));
215 safeputs(ndo, tptr + 5, len - 5);
216 }
217 break;
218
219 case EAP_TYPE_NAK:
220 count = 5;
221
222 /*
223 * one or more octets indicating
224 * the desired authentication
225 * type one octet per type
226 */
227 while (count < len) {
228 ND_TCHECK_8BITS(tptr+count);
229 ND_PRINT((ndo, " %s (%u),",
230 tok2str(eap_type_values, "unknown", *(tptr+count)),
231 *(tptr + count)));
232 count++;
233 }
234 break;
235
236 case EAP_TYPE_TTLS:
237 case EAP_TYPE_TLS:
238 ND_TCHECK_8BITS(tptr + 5);
239 if (subtype == EAP_TYPE_TTLS)
240 ND_PRINT((ndo, " TTLSv%u",
241 EAP_TTLS_VERSION(*(tptr + 5))));
242 ND_PRINT((ndo, " flags [%s] 0x%02x,",
243 bittok2str(eap_tls_flags_values, "none", *(tptr+5)),
244 *(tptr + 5)));
245
246 if (EAP_TLS_EXTRACT_BIT_L(*(tptr+5))) {
247 ND_TCHECK_32BITS(tptr + 6);
248 ND_PRINT((ndo, " len %u", EXTRACT_32BITS(tptr + 6)));
249 }
250 break;
251
252 case EAP_TYPE_FAST:
253 ND_TCHECK_8BITS(tptr + 5);
254 ND_PRINT((ndo, " FASTv%u",
255 EAP_TTLS_VERSION(*(tptr + 5))));
256 ND_PRINT((ndo, " flags [%s] 0x%02x,",
257 bittok2str(eap_tls_flags_values, "none", *(tptr+5)),
258 *(tptr + 5)));
259
260 if (EAP_TLS_EXTRACT_BIT_L(*(tptr+5))) {
261 ND_TCHECK_32BITS(tptr + 6);
262 ND_PRINT((ndo, " len %u", EXTRACT_32BITS(tptr + 6)));
263 }
264
265 /* FIXME - TLV attributes follow */
266 break;
267
268 case EAP_TYPE_AKA:
269 case EAP_TYPE_SIM:
270 ND_TCHECK_8BITS(tptr + 5);
271 ND_PRINT((ndo, " subtype [%s] 0x%02x,",
272 tok2str(eap_aka_subtype_values, "unknown", *(tptr+5)),
273 *(tptr + 5)));
274
275 /* FIXME - TLV attributes follow */
276 break;
277
278 case EAP_TYPE_MD5_CHALLENGE:
279 case EAP_TYPE_OTP:
280 case EAP_TYPE_GTC:
281 case EAP_TYPE_EXPANDED_TYPES:
282 case EAP_TYPE_EXPERIMENTAL:
283 default:
284 break;
285 }
286 }
287 break;
288
289 case EAP_FRAME_TYPE_LOGOFF:
290 case EAP_FRAME_TYPE_ENCAP_ASF_ALERT:
291 default:
292 break;
293 }
294 return;
295
296 trunc:
297 ND_PRINT((ndo, "\n\t[|EAP]"));
298 }
299
300 /*
301 * Local Variables:
302 * c-basic-offset: 4
303 * End:
304 */
305