xref: /netbsd-src/external/bsd/tcpdump/dist/print-eap.c (revision 181254a7b1bdde6873432bffef2d2decc4b5c22f)
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 #include <sys/cdefs.h>
24 #ifndef lint
25 __RCSID("$NetBSD: print-eap.c,v 1.7 2017/09/08 14:01:13 christos Exp $");
26 #endif
27 
28 #ifdef HAVE_CONFIG_H
29 #include "config.h"
30 #endif
31 
32 #include <netdissect-stdinc.h>
33 
34 #include "netdissect.h"
35 #include "extract.h"
36 
37 #define	EAP_FRAME_TYPE_PACKET		0
38 #define	EAP_FRAME_TYPE_START		1
39 #define	EAP_FRAME_TYPE_LOGOFF		2
40 #define	EAP_FRAME_TYPE_KEY		3
41 #define	EAP_FRAME_TYPE_ENCAP_ASF_ALERT	4
42 
43 struct eap_frame_t {
44     unsigned char   version;
45     unsigned char   type;
46     unsigned char   length[2];
47 };
48 
49 static const struct tok eap_frame_type_values[] = {
50     { EAP_FRAME_TYPE_PACKET,      	"EAP packet" },
51     { EAP_FRAME_TYPE_START,    		"EAPOL start" },
52     { EAP_FRAME_TYPE_LOGOFF,      	"EAPOL logoff" },
53     { EAP_FRAME_TYPE_KEY,      		"EAPOL key" },
54     { EAP_FRAME_TYPE_ENCAP_ASF_ALERT, 	"Encapsulated ASF alert" },
55     { 0, NULL}
56 };
57 
58 /* RFC 3748 */
59 struct eap_packet_t {
60     unsigned char	code;
61     unsigned char	id;
62     unsigned char	length[2];
63 };
64 
65 #define		EAP_REQUEST	1
66 #define		EAP_RESPONSE	2
67 #define		EAP_SUCCESS	3
68 #define		EAP_FAILURE	4
69 
70 static const struct tok eap_code_values[] = {
71     { EAP_REQUEST,	"Request" },
72     { EAP_RESPONSE,	"Response" },
73     { EAP_SUCCESS,	"Success" },
74     { EAP_FAILURE,	"Failure" },
75     { 0, NULL}
76 };
77 
78 #define		EAP_TYPE_NO_PROPOSED	0
79 #define		EAP_TYPE_IDENTITY	1
80 #define		EAP_TYPE_NOTIFICATION	2
81 #define		EAP_TYPE_NAK		3
82 #define		EAP_TYPE_MD5_CHALLENGE	4
83 #define		EAP_TYPE_OTP		5
84 #define		EAP_TYPE_GTC		6
85 #define		EAP_TYPE_TLS		13		/* RFC 2716 */
86 #define		EAP_TYPE_SIM		18		/* RFC 4186 */
87 #define		EAP_TYPE_TTLS		21		/* draft-funk-eap-ttls-v0-01.txt */
88 #define		EAP_TYPE_AKA		23		/* RFC 4187 */
89 #define		EAP_TYPE_FAST		43		/* RFC 4851 */
90 #define		EAP_TYPE_EXPANDED_TYPES	254
91 #define		EAP_TYPE_EXPERIMENTAL	255
92 
93 static const struct tok eap_type_values[] = {
94     { EAP_TYPE_NO_PROPOSED,	"No proposed" },
95     { EAP_TYPE_IDENTITY,	"Identity" },
96     { EAP_TYPE_NOTIFICATION,    "Notification" },
97     { EAP_TYPE_NAK,      	"Nak" },
98     { EAP_TYPE_MD5_CHALLENGE,   "MD5-challenge" },
99     { EAP_TYPE_OTP,      	"OTP" },
100     { EAP_TYPE_GTC,      	"GTC" },
101     { EAP_TYPE_TLS,      	"TLS" },
102     { EAP_TYPE_SIM,      	"SIM" },
103     { EAP_TYPE_TTLS,      	"TTLS" },
104     { EAP_TYPE_AKA,      	"AKA" },
105     { EAP_TYPE_FAST,      	"FAST" },
106     { EAP_TYPE_EXPANDED_TYPES,  "Expanded types" },
107     { EAP_TYPE_EXPERIMENTAL,    "Experimental" },
108     { 0, NULL}
109 };
110 
111 #define EAP_TLS_EXTRACT_BIT_L(x) 	(((x)&0x80)>>7)
112 
113 /* RFC 2716 - EAP TLS bits */
114 #define EAP_TLS_FLAGS_LEN_INCLUDED		(1 << 7)
115 #define EAP_TLS_FLAGS_MORE_FRAGMENTS		(1 << 6)
116 #define EAP_TLS_FLAGS_START			(1 << 5)
117 
118 static const struct tok eap_tls_flags_values[] = {
119 	{ EAP_TLS_FLAGS_LEN_INCLUDED, "L bit" },
120 	{ EAP_TLS_FLAGS_MORE_FRAGMENTS, "More fragments bit"},
121 	{ EAP_TLS_FLAGS_START, "Start bit"},
122 	{ 0, NULL}
123 };
124 
125 #define EAP_TTLS_VERSION(x)		((x)&0x07)
126 
127 /* EAP-AKA and EAP-SIM - RFC 4187 */
128 #define EAP_AKA_CHALLENGE		1
129 #define EAP_AKA_AUTH_REJECT		2
130 #define EAP_AKA_SYNC_FAILURE		4
131 #define EAP_AKA_IDENTITY		5
132 #define EAP_SIM_START			10
133 #define EAP_SIM_CHALLENGE		11
134 #define EAP_AKA_NOTIFICATION		12
135 #define EAP_AKA_REAUTH			13
136 #define EAP_AKA_CLIENT_ERROR		14
137 
138 static const struct tok eap_aka_subtype_values[] = {
139     { EAP_AKA_CHALLENGE,	"Challenge" },
140     { EAP_AKA_AUTH_REJECT,	"Auth reject" },
141     { EAP_AKA_SYNC_FAILURE,	"Sync failure" },
142     { EAP_AKA_IDENTITY,		"Identity" },
143     { EAP_SIM_START,		"Start" },
144     { EAP_SIM_CHALLENGE,	"Challenge" },
145     { EAP_AKA_NOTIFICATION,	"Notification" },
146     { EAP_AKA_REAUTH,		"Reauth" },
147     { EAP_AKA_CLIENT_ERROR,	"Client error" },
148     { 0, NULL}
149 };
150 
151 /*
152  * Print EAP requests / responses
153  */
154 void
155 eap_print(netdissect_options *ndo,
156           register const u_char *cp,
157           u_int length)
158 {
159     const struct eap_frame_t *eap;
160     const u_char *tptr;
161     u_int tlen, type, subtype;
162     int count=0, len;
163 
164     tptr = cp;
165     tlen = length;
166     eap = (const struct eap_frame_t *)cp;
167     ND_TCHECK(*eap);
168 
169     /* in non-verbose mode just lets print the basic info */
170     if (ndo->ndo_vflag < 1) {
171 	ND_PRINT((ndo, "%s (%u) v%u, len %u",
172                tok2str(eap_frame_type_values, "unknown", eap->type),
173                eap->type,
174                eap->version,
175                EXTRACT_16BITS(eap->length)));
176 	return;
177     }
178 
179     ND_PRINT((ndo, "%s (%u) v%u, len %u",
180            tok2str(eap_frame_type_values, "unknown", eap->type),
181            eap->type,
182            eap->version,
183            EXTRACT_16BITS(eap->length)));
184 
185     tptr += sizeof(const struct eap_frame_t);
186     tlen -= sizeof(const struct eap_frame_t);
187 
188     switch (eap->type) {
189     case EAP_FRAME_TYPE_PACKET:
190         ND_TCHECK_8BITS(tptr);
191         type = *(tptr);
192         ND_TCHECK_16BITS(tptr+2);
193         len = EXTRACT_16BITS(tptr+2);
194         ND_PRINT((ndo, ", %s (%u), id %u, len %u",
195                tok2str(eap_code_values, "unknown", type),
196                type,
197                *(tptr+1),
198                len));
199 
200         ND_TCHECK2(*tptr, len);
201 
202         if (type <= 2) { /* For EAP_REQUEST and EAP_RESPONSE only */
203             ND_TCHECK_8BITS(tptr+4);
204             subtype = *(tptr+4);
205             ND_PRINT((ndo, "\n\t\t Type %s (%u)",
206                    tok2str(eap_type_values, "unknown", subtype),
207                    subtype));
208 
209             switch (subtype) {
210             case EAP_TYPE_IDENTITY:
211                 if (len - 5 > 0) {
212                     ND_PRINT((ndo, ", Identity: "));
213                     safeputs(ndo, tptr + 5, len - 5);
214                 }
215                 break;
216 
217             case EAP_TYPE_NOTIFICATION:
218                 if (len - 5 > 0) {
219                     ND_PRINT((ndo, ", Notification: "));
220                     safeputs(ndo, tptr + 5, len - 5);
221                 }
222                 break;
223 
224             case EAP_TYPE_NAK:
225                 count = 5;
226 
227                 /*
228                  * one or more octets indicating
229                  * the desired authentication
230                  * type one octet per type
231                  */
232                 while (count < len) {
233                     ND_TCHECK_8BITS(tptr+count);
234                     ND_PRINT((ndo, " %s (%u),",
235                            tok2str(eap_type_values, "unknown", *(tptr+count)),
236                            *(tptr + count)));
237                     count++;
238                 }
239                 break;
240 
241             case EAP_TYPE_TTLS:
242             case EAP_TYPE_TLS:
243                 ND_TCHECK_8BITS(tptr + 5);
244                 if (subtype == EAP_TYPE_TTLS)
245                     ND_PRINT((ndo, " TTLSv%u",
246                            EAP_TTLS_VERSION(*(tptr + 5))));
247                 ND_PRINT((ndo, " flags [%s] 0x%02x,",
248                        bittok2str(eap_tls_flags_values, "none", *(tptr+5)),
249                        *(tptr + 5)));
250 
251                 if (EAP_TLS_EXTRACT_BIT_L(*(tptr+5))) {
252                     ND_TCHECK_32BITS(tptr + 6);
253 		    ND_PRINT((ndo, " len %u", EXTRACT_32BITS(tptr + 6)));
254                 }
255                 break;
256 
257             case EAP_TYPE_FAST:
258                 ND_TCHECK_8BITS(tptr + 5);
259                 ND_PRINT((ndo, " FASTv%u",
260                        EAP_TTLS_VERSION(*(tptr + 5))));
261                 ND_PRINT((ndo, " flags [%s] 0x%02x,",
262                        bittok2str(eap_tls_flags_values, "none", *(tptr+5)),
263                        *(tptr + 5)));
264 
265                 if (EAP_TLS_EXTRACT_BIT_L(*(tptr+5))) {
266                     ND_TCHECK_32BITS(tptr + 6);
267                     ND_PRINT((ndo, " len %u", EXTRACT_32BITS(tptr + 6)));
268                 }
269 
270                 /* FIXME - TLV attributes follow */
271                 break;
272 
273             case EAP_TYPE_AKA:
274             case EAP_TYPE_SIM:
275                 ND_TCHECK_8BITS(tptr + 5);
276                 ND_PRINT((ndo, " subtype [%s] 0x%02x,",
277                        tok2str(eap_aka_subtype_values, "unknown", *(tptr+5)),
278                        *(tptr + 5)));
279 
280                 /* FIXME - TLV attributes follow */
281                 break;
282 
283             case EAP_TYPE_MD5_CHALLENGE:
284             case EAP_TYPE_OTP:
285             case EAP_TYPE_GTC:
286             case EAP_TYPE_EXPANDED_TYPES:
287             case EAP_TYPE_EXPERIMENTAL:
288             default:
289                 break;
290             }
291         }
292         break;
293 
294     case EAP_FRAME_TYPE_LOGOFF:
295     case EAP_FRAME_TYPE_ENCAP_ASF_ALERT:
296     default:
297         break;
298     }
299     return;
300 
301  trunc:
302     ND_PRINT((ndo, "\n\t[|EAP]"));
303 }
304 
305 /*
306  * Local Variables:
307  * c-basic-offset: 4
308  * End:
309  */
310