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 1.8 2023/08/17 20:19:40 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 nd_uint8_t version; 45 nd_uint8_t type; 46 nd_uint16_t length; 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 nd_uint8_t code; 61 nd_uint8_t id; 62 nd_uint16_t length; 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 5216 */ 86 #define EAP_TYPE_SIM 18 /* RFC 4186 */ 87 #define EAP_TYPE_TTLS 21 /* RFC 5281, 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 5216 - 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 const u_char *cp, 157 u_int length) 158 { 159 u_int type, subtype, len; 160 u_int count; 161 const char *sep; 162 163 type = GET_U_1(cp); 164 len = GET_BE_U_2(cp + 2); 165 if (len != length) { 166 /* 167 * Probably a fragment; in some cases the fragmentation might 168 * not put an EAP header on every packet, if reassembly can 169 * be done without that (e.g., fragmentation to make a message 170 * fit in multiple TLVs in a RADIUS packet). 171 */ 172 ND_PRINT("EAP fragment?"); 173 return; 174 } 175 ND_PRINT("%s (%u), id %u, len %u", 176 tok2str(eap_code_values, "unknown", type), 177 type, 178 GET_U_1((cp + 1)), 179 len); 180 if (len < 4) { 181 ND_PRINT(" (too short for EAP header)"); 182 return; 183 } 184 185 ND_TCHECK_LEN(cp, len); 186 187 if (type == EAP_REQUEST || type == EAP_RESPONSE) { 188 /* RFC 3748 Section 4.1 */ 189 if (len < 5) { 190 ND_PRINT(" (too short for EAP request/response)"); 191 return; 192 } 193 subtype = GET_U_1(cp + 4); 194 ND_PRINT("\n\t\t Type %s (%u)", 195 tok2str(eap_type_values, "unknown", subtype), 196 subtype); 197 198 switch (subtype) { 199 case EAP_TYPE_IDENTITY: 200 /* According to RFC 3748, the message is optional */ 201 if (len > 5) { 202 ND_PRINT(", Identity: "); 203 nd_printjnp(ndo, cp + 5, len - 5); 204 } 205 break; 206 207 case EAP_TYPE_NOTIFICATION: 208 /* According to RFC 3748, there must be at least one octet of message */ 209 if (len < 6) { 210 ND_PRINT(" (too short for EAP Notification request/response)"); 211 return; 212 } 213 ND_PRINT(", Notification: "); 214 nd_printjnp(ndo, cp + 5, len - 5); 215 break; 216 217 case EAP_TYPE_NAK: 218 /* 219 * one or more octets indicating 220 * the desired authentication 221 * type one octet per type 222 */ 223 if (len < 6) { 224 ND_PRINT(" (too short for EAP Legacy NAK request/response)"); 225 return; 226 } 227 sep = ""; 228 for (count = 5; count < len; count++) { 229 ND_PRINT("%s %s (%u)", sep, 230 tok2str(eap_type_values, "unknown", GET_U_1((cp + count))), 231 GET_U_1(cp + count)); 232 sep = ","; 233 } 234 break; 235 236 case EAP_TYPE_TTLS: 237 case EAP_TYPE_TLS: 238 if (len < 6) { 239 ND_PRINT(" (too short for EAP TLS/TTLS request/response)"); 240 return; 241 } 242 if (subtype == EAP_TYPE_TTLS) 243 ND_PRINT(" TTLSv%u", 244 EAP_TTLS_VERSION(GET_U_1((cp + 5)))); 245 ND_PRINT(" flags [%s] 0x%02x", 246 bittok2str(eap_tls_flags_values, "none", GET_U_1((cp + 5))), 247 GET_U_1(cp + 5)); 248 249 if (EAP_TLS_EXTRACT_BIT_L(GET_U_1(cp + 5))) { 250 if (len < 10) { 251 ND_PRINT(" (too short for EAP TLS/TTLS request/response with length)"); 252 return; 253 } 254 ND_PRINT(", len %u", GET_BE_U_4(cp + 6)); 255 } 256 break; 257 258 case EAP_TYPE_FAST: 259 if (len < 6) { 260 ND_PRINT(" (too short for EAP FAST request/response)"); 261 return; 262 } 263 ND_PRINT(" FASTv%u", 264 EAP_TTLS_VERSION(GET_U_1((cp + 5)))); 265 ND_PRINT(" flags [%s] 0x%02x", 266 bittok2str(eap_tls_flags_values, "none", GET_U_1((cp + 5))), 267 GET_U_1(cp + 5)); 268 269 if (EAP_TLS_EXTRACT_BIT_L(GET_U_1(cp + 5))) { 270 if (len < 10) { 271 ND_PRINT(" (too short for EAP FAST request/response with length)"); 272 return; 273 } 274 ND_PRINT(", len %u", GET_BE_U_4(cp + 6)); 275 } 276 277 /* FIXME - TLV attributes follow */ 278 break; 279 280 case EAP_TYPE_AKA: 281 case EAP_TYPE_SIM: 282 if (len < 6) { 283 ND_PRINT(" (too short for EAP SIM/AKA request/response)"); 284 return; 285 } 286 ND_PRINT(" subtype [%s] 0x%02x", 287 tok2str(eap_aka_subtype_values, "unknown", GET_U_1((cp + 5))), 288 GET_U_1(cp + 5)); 289 290 /* FIXME - TLV attributes follow */ 291 break; 292 293 case EAP_TYPE_MD5_CHALLENGE: 294 case EAP_TYPE_OTP: 295 case EAP_TYPE_GTC: 296 case EAP_TYPE_EXPANDED_TYPES: 297 case EAP_TYPE_EXPERIMENTAL: 298 default: 299 break; 300 } 301 } 302 return; 303 trunc: 304 nd_print_trunc(ndo); 305 } 306 307 void 308 eapol_print(netdissect_options *ndo, 309 const u_char *cp) 310 { 311 const struct eap_frame_t *eap; 312 u_int eap_type, eap_len; 313 314 ndo->ndo_protocol = "eap"; 315 eap = (const struct eap_frame_t *)cp; 316 ND_TCHECK_SIZE(eap); 317 eap_type = GET_U_1(eap->type); 318 319 ND_PRINT("%s (%u) v%u, len %u", 320 tok2str(eap_frame_type_values, "unknown", eap_type), 321 eap_type, 322 GET_U_1(eap->version), 323 GET_BE_U_2(eap->length)); 324 if (ndo->ndo_vflag < 1) 325 return; 326 327 cp += sizeof(struct eap_frame_t); 328 eap_len = GET_BE_U_2(eap->length); 329 330 switch (eap_type) { 331 case EAP_FRAME_TYPE_PACKET: 332 if (eap_len == 0) 333 goto trunc; 334 ND_PRINT(", "); 335 eap_print(ndo, cp, eap_len); 336 return; 337 case EAP_FRAME_TYPE_LOGOFF: 338 case EAP_FRAME_TYPE_ENCAP_ASF_ALERT: 339 default: 340 break; 341 } 342 return; 343 344 trunc: 345 nd_print_trunc(ndo); 346 } 347