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