The Tcpdump Group git mirrors - tcpdump/blob - print-eap.c

   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
 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  */