1 /* 2 * hostapd / EAP-SIM (RFC 4186) 3 * Copyright (c) 2005-2012, Jouni Malinen <j (at) w1.fi> 4 * 5 * This software may be distributed under the terms of the BSD license. 6 * See README for more details. 7 */ 8 9 #include "includes.h" 10 11 #include "common.h" 12 #include "crypto/random.h" 13 #include "eap_server/eap_i.h" 14 #include "eap_common/eap_sim_common.h" 15 #include "eap_server/eap_sim_db.h" 16 17 18 struct eap_sim_data { 19 u8 mk[EAP_SIM_MK_LEN]; 20 u8 nonce_mt[EAP_SIM_NONCE_MT_LEN]; 21 u8 nonce_s[EAP_SIM_NONCE_S_LEN]; 22 u8 k_aut[EAP_SIM_K_AUT_LEN]; 23 u8 k_encr[EAP_SIM_K_ENCR_LEN]; 24 u8 msk[EAP_SIM_KEYING_DATA_LEN]; 25 u8 emsk[EAP_EMSK_LEN]; 26 u8 kc[EAP_SIM_MAX_CHAL][EAP_SIM_KC_LEN]; 27 u8 sres[EAP_SIM_MAX_CHAL][EAP_SIM_SRES_LEN]; 28 u8 rand[EAP_SIM_MAX_CHAL][GSM_RAND_LEN]; 29 int num_chal; 30 enum { 31 START, CHALLENGE, REAUTH, NOTIFICATION, SUCCESS, FAILURE 32 } state; 33 char *next_pseudonym; 34 char *next_reauth_id; 35 u16 counter; 36 struct eap_sim_reauth *reauth; 37 u16 notification; 38 int use_result_ind; 39 int start_round; 40 char permanent[20]; /* Permanent username */ 41 }; 42 43 44 static const char * eap_sim_state_txt(int state) 45 { 46 switch (state) { 47 case START: 48 return "START"; 49 case CHALLENGE: 50 return "CHALLENGE"; 51 case REAUTH: 52 return "REAUTH"; 53 case SUCCESS: 54 return "SUCCESS"; 55 case FAILURE: 56 return "FAILURE"; 57 case NOTIFICATION: 58 return "NOTIFICATION"; 59 default: 60 return "Unknown?!"; 61 } 62 } 63 64 65 static void eap_sim_state(struct eap_sim_data *data, int state) 66 { 67 wpa_printf(MSG_DEBUG, "EAP-SIM: %s -> %s", 68 eap_sim_state_txt(data->state), 69 eap_sim_state_txt(state)); 70 data->state = state; 71 } 72 73 74 static void * eap_sim_init(struct eap_sm *sm) 75 { 76 struct eap_sim_data *data; 77 78 if (sm->eap_sim_db_priv == NULL) { 79 wpa_printf(MSG_WARNING, "EAP-SIM: eap_sim_db not configured"); 80 return NULL; 81 } 82 83 data = os_zalloc(sizeof(*data)); 84 if (data == NULL) 85 return NULL; 86 data->state = START; 87 88 return data; 89 } 90 91 92 static void eap_sim_reset(struct eap_sm *sm, void *priv) 93 { 94 struct eap_sim_data *data = priv; 95 os_free(data->next_pseudonym); 96 os_free(data->next_reauth_id); 97 os_free(data); 98 } 99 100 101 static struct wpabuf * eap_sim_build_start(struct eap_sm *sm, 102 struct eap_sim_data *data, u8 id) 103 { 104 struct eap_sim_msg *msg; 105 u8 ver[2]; 106 107 wpa_printf(MSG_DEBUG, "EAP-SIM: Generating Start"); 108 msg = eap_sim_msg_init(EAP_CODE_REQUEST, id, EAP_TYPE_SIM, 109 EAP_SIM_SUBTYPE_START); 110 data->start_round++; 111 if (data->start_round == 1) { 112 /* 113 * RFC 4186, Chap. 4.2.4 recommends that identity from EAP is 114 * ignored and the SIM/Start is used to request the identity. 115 */ 116 wpa_printf(MSG_DEBUG, " AT_ANY_ID_REQ"); 117 eap_sim_msg_add(msg, EAP_SIM_AT_ANY_ID_REQ, 0, NULL, 0); 118 } else if (data->start_round > 3) { 119 /* Cannot use more than three rounds of Start messages */ 120 return NULL; 121 } else if (data->start_round == 0) { 122 /* 123 * This is a special case that is used to recover from 124 * AT_COUNTER_TOO_SMALL during re-authentication. Since we 125 * already know the identity of the peer, there is no need to 126 * request any identity in this case. 127 */ 128 } else if (sm->identity && sm->identity_len > 0 && 129 sm->identity[0] == EAP_SIM_REAUTH_ID_PREFIX) { 130 /* Reauth id may have expired - try fullauth */ 131 wpa_printf(MSG_DEBUG, " AT_FULLAUTH_ID_REQ"); 132 eap_sim_msg_add(msg, EAP_SIM_AT_FULLAUTH_ID_REQ, 0, NULL, 0); 133 } else { 134 wpa_printf(MSG_DEBUG, " AT_PERMANENT_ID_REQ"); 135 eap_sim_msg_add(msg, EAP_SIM_AT_PERMANENT_ID_REQ, 0, NULL, 0); 136 } 137 wpa_printf(MSG_DEBUG, " AT_VERSION_LIST"); 138 ver[0] = 0; 139 ver[1] = EAP_SIM_VERSION; 140 eap_sim_msg_add(msg, EAP_SIM_AT_VERSION_LIST, sizeof(ver), 141 ver, sizeof(ver)); 142 return eap_sim_msg_finish(msg, NULL, NULL, 0); 143 } 144 145 146 static int eap_sim_build_encr(struct eap_sm *sm, struct eap_sim_data *data, 147 struct eap_sim_msg *msg, u16 counter, 148 const u8 *nonce_s) 149 { 150 os_free(data->next_pseudonym); 151 if (nonce_s == NULL) { 152 data->next_pseudonym = 153 eap_sim_db_get_next_pseudonym(sm->eap_sim_db_priv, 154 EAP_SIM_DB_SIM); 155 } else { 156 /* Do not update pseudonym during re-authentication */ 157 data->next_pseudonym = NULL; 158 } 159 os_free(data->next_reauth_id); 160 if (data->counter <= EAP_SIM_MAX_FAST_REAUTHS) { 161 data->next_reauth_id = 162 eap_sim_db_get_next_reauth_id(sm->eap_sim_db_priv, 163 EAP_SIM_DB_SIM); 164 } else { 165 wpa_printf(MSG_DEBUG, "EAP-SIM: Max fast re-authentication " 166 "count exceeded - force full authentication"); 167 data->next_reauth_id = NULL; 168 } 169 170 if (data->next_pseudonym == NULL && data->next_reauth_id == NULL && 171 counter == 0 && nonce_s == NULL) 172 return 0; 173 174 wpa_printf(MSG_DEBUG, " AT_IV"); 175 wpa_printf(MSG_DEBUG, " AT_ENCR_DATA"); 176 eap_sim_msg_add_encr_start(msg, EAP_SIM_AT_IV, EAP_SIM_AT_ENCR_DATA); 177 178 if (counter > 0) { 179 wpa_printf(MSG_DEBUG, " *AT_COUNTER (%u)", counter); 180 eap_sim_msg_add(msg, EAP_SIM_AT_COUNTER, counter, NULL, 0); 181 } 182 183 if (nonce_s) { 184 wpa_printf(MSG_DEBUG, " *AT_NONCE_S"); 185 eap_sim_msg_add(msg, EAP_SIM_AT_NONCE_S, 0, nonce_s, 186 EAP_SIM_NONCE_S_LEN); 187 } 188 189 if (data->next_pseudonym) { 190 wpa_printf(MSG_DEBUG, " *AT_NEXT_PSEUDONYM (%s)", 191 data->next_pseudonym); 192 eap_sim_msg_add(msg, EAP_SIM_AT_NEXT_PSEUDONYM, 193 os_strlen(data->next_pseudonym), 194 (u8 *) data->next_pseudonym, 195 os_strlen(data->next_pseudonym)); 196 } 197 198 if (data->next_reauth_id) { 199 wpa_printf(MSG_DEBUG, " *AT_NEXT_REAUTH_ID (%s)", 200 data->next_reauth_id); 201 eap_sim_msg_add(msg, EAP_SIM_AT_NEXT_REAUTH_ID, 202 os_strlen(data->next_reauth_id), 203 (u8 *) data->next_reauth_id, 204 os_strlen(data->next_reauth_id)); 205 } 206 207 if (eap_sim_msg_add_encr_end(msg, data->k_encr, EAP_SIM_AT_PADDING)) { 208 wpa_printf(MSG_WARNING, "EAP-SIM: Failed to encrypt " 209 "AT_ENCR_DATA"); 210 return -1; 211 } 212 213 return 0; 214 } 215 216 217 static struct wpabuf * eap_sim_build_challenge(struct eap_sm *sm, 218 struct eap_sim_data *data, 219 u8 id) 220 { 221 struct eap_sim_msg *msg; 222 223 wpa_printf(MSG_DEBUG, "EAP-SIM: Generating Challenge"); 224 msg = eap_sim_msg_init(EAP_CODE_REQUEST, id, EAP_TYPE_SIM, 225 EAP_SIM_SUBTYPE_CHALLENGE); 226 wpa_printf(MSG_DEBUG, " AT_RAND"); 227 eap_sim_msg_add(msg, EAP_SIM_AT_RAND, 0, (u8 *) data->rand, 228 data->num_chal * GSM_RAND_LEN); 229 230 if (eap_sim_build_encr(sm, data, msg, 0, NULL)) { 231 eap_sim_msg_free(msg); 232 return NULL; 233 } 234 235 if (sm->eap_sim_aka_result_ind) { 236 wpa_printf(MSG_DEBUG, " AT_RESULT_IND"); 237 eap_sim_msg_add(msg, EAP_SIM_AT_RESULT_IND, 0, NULL, 0); 238 } 239 240 wpa_printf(MSG_DEBUG, " AT_MAC"); 241 eap_sim_msg_add_mac(msg, EAP_SIM_AT_MAC); 242 return eap_sim_msg_finish(msg, data->k_aut, data->nonce_mt, 243 EAP_SIM_NONCE_MT_LEN); 244 } 245 246 247 static struct wpabuf * eap_sim_build_reauth(struct eap_sm *sm, 248 struct eap_sim_data *data, u8 id) 249 { 250 struct eap_sim_msg *msg; 251 252 wpa_printf(MSG_DEBUG, "EAP-SIM: Generating Re-authentication"); 253 254 if (random_get_bytes(data->nonce_s, EAP_SIM_NONCE_S_LEN)) 255 return NULL; 256 wpa_hexdump_key(MSG_MSGDUMP, "EAP-SIM: NONCE_S", 257 data->nonce_s, EAP_SIM_NONCE_S_LEN); 258 259 eap_sim_derive_keys(data->mk, data->k_encr, data->k_aut, data->msk, 260 data->emsk); 261 eap_sim_derive_keys_reauth(data->counter, sm->identity, 262 sm->identity_len, data->nonce_s, data->mk, 263 data->msk, data->emsk); 264 265 msg = eap_sim_msg_init(EAP_CODE_REQUEST, id, EAP_TYPE_SIM, 266 EAP_SIM_SUBTYPE_REAUTHENTICATION); 267 268 if (eap_sim_build_encr(sm, data, msg, data->counter, data->nonce_s)) { 269 eap_sim_msg_free(msg); 270 return NULL; 271 } 272 273 if (sm->eap_sim_aka_result_ind) { 274 wpa_printf(MSG_DEBUG, " AT_RESULT_IND"); 275 eap_sim_msg_add(msg, EAP_SIM_AT_RESULT_IND, 0, NULL, 0); 276 } 277 278 wpa_printf(MSG_DEBUG, " AT_MAC"); 279 eap_sim_msg_add_mac(msg, EAP_SIM_AT_MAC); 280 return eap_sim_msg_finish(msg, data->k_aut, NULL, 0); 281 } 282 283 284 static struct wpabuf * eap_sim_build_notification(struct eap_sm *sm, 285 struct eap_sim_data *data, 286 u8 id) 287 { 288 struct eap_sim_msg *msg; 289 290 wpa_printf(MSG_DEBUG, "EAP-SIM: Generating Notification"); 291 msg = eap_sim_msg_init(EAP_CODE_REQUEST, id, EAP_TYPE_SIM, 292 EAP_SIM_SUBTYPE_NOTIFICATION); 293 wpa_printf(MSG_DEBUG, " AT_NOTIFICATION (%d)", data->notification); 294 eap_sim_msg_add(msg, EAP_SIM_AT_NOTIFICATION, data->notification, 295 NULL, 0); 296 if (data->use_result_ind) { 297 if (data->reauth) { 298 wpa_printf(MSG_DEBUG, " AT_IV"); 299 wpa_printf(MSG_DEBUG, " AT_ENCR_DATA"); 300 eap_sim_msg_add_encr_start(msg, EAP_SIM_AT_IV, 301 EAP_SIM_AT_ENCR_DATA); 302 wpa_printf(MSG_DEBUG, " *AT_COUNTER (%u)", 303 data->counter); 304 eap_sim_msg_add(msg, EAP_SIM_AT_COUNTER, data->counter, 305 NULL, 0); 306 307 if (eap_sim_msg_add_encr_end(msg, data->k_encr, 308 EAP_SIM_AT_PADDING)) { 309 wpa_printf(MSG_WARNING, "EAP-SIM: Failed to " 310 "encrypt AT_ENCR_DATA"); 311 eap_sim_msg_free(msg); 312 return NULL; 313 } 314 } 315 316 wpa_printf(MSG_DEBUG, " AT_MAC"); 317 eap_sim_msg_add_mac(msg, EAP_SIM_AT_MAC); 318 } 319 return eap_sim_msg_finish(msg, data->k_aut, NULL, 0); 320 } 321 322 323 static struct wpabuf * eap_sim_buildReq(struct eap_sm *sm, void *priv, u8 id) 324 { 325 struct eap_sim_data *data = priv; 326 327 switch (data->state) { 328 case START: 329 return eap_sim_build_start(sm, data, id); 330 case CHALLENGE: 331 return eap_sim_build_challenge(sm, data, id); 332 case REAUTH: 333 return eap_sim_build_reauth(sm, data, id); 334 case NOTIFICATION: 335 return eap_sim_build_notification(sm, data, id); 336 default: 337 wpa_printf(MSG_DEBUG, "EAP-SIM: Unknown state %d in " 338 "buildReq", data->state); 339 break; 340 } 341 return NULL; 342 } 343 344 345 static Boolean eap_sim_check(struct eap_sm *sm, void *priv, 346 struct wpabuf *respData) 347 { 348 const u8 *pos; 349 size_t len; 350 351 pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_SIM, respData, &len); 352 if (pos == NULL || len < 3) { 353 wpa_printf(MSG_INFO, "EAP-SIM: Invalid frame"); 354 return TRUE; 355 } 356 357 return FALSE; 358 } 359 360 361 static Boolean eap_sim_unexpected_subtype(struct eap_sim_data *data, 362 u8 subtype) 363 { 364 if (subtype == EAP_SIM_SUBTYPE_CLIENT_ERROR) 365 return FALSE; 366 367 switch (data->state) { 368 case START: 369 if (subtype != EAP_SIM_SUBTYPE_START) { 370 wpa_printf(MSG_INFO, "EAP-SIM: Unexpected response " 371 "subtype %d", subtype); 372 return TRUE; 373 } 374 break; 375 case CHALLENGE: 376 if (subtype != EAP_SIM_SUBTYPE_CHALLENGE) { 377 wpa_printf(MSG_INFO, "EAP-SIM: Unexpected response " 378 "subtype %d", subtype); 379 return TRUE; 380 } 381 break; 382 case REAUTH: 383 if (subtype != EAP_SIM_SUBTYPE_REAUTHENTICATION) { 384 wpa_printf(MSG_INFO, "EAP-SIM: Unexpected response " 385 "subtype %d", subtype); 386 return TRUE; 387 } 388 break; 389 case NOTIFICATION: 390 if (subtype != EAP_SIM_SUBTYPE_NOTIFICATION) { 391 wpa_printf(MSG_INFO, "EAP-SIM: Unexpected response " 392 "subtype %d", subtype); 393 return TRUE; 394 } 395 break; 396 default: 397 wpa_printf(MSG_INFO, "EAP-SIM: Unexpected state (%d) for " 398 "processing a response", data->state); 399 return TRUE; 400 } 401 402 return FALSE; 403 } 404 405 406 static int eap_sim_supported_ver(struct eap_sim_data *data, int version) 407 { 408 return version == EAP_SIM_VERSION; 409 } 410 411 412 static void eap_sim_process_start(struct eap_sm *sm, 413 struct eap_sim_data *data, 414 struct wpabuf *respData, 415 struct eap_sim_attrs *attr) 416 { 417 size_t identity_len; 418 u8 ver_list[2]; 419 u8 *new_identity; 420 char *username; 421 422 wpa_printf(MSG_DEBUG, "EAP-SIM: Receive start response"); 423 424 if (data->start_round == 0) { 425 /* 426 * Special case for AT_COUNTER_TOO_SMALL recovery - no identity 427 * was requested since we already know it. 428 */ 429 goto skip_id_update; 430 } 431 432 /* 433 * We always request identity in SIM/Start, so the peer is required to 434 * have replied with one. 435 */ 436 if (!attr->identity || attr->identity_len == 0) { 437 wpa_printf(MSG_DEBUG, "EAP-SIM: Peer did not provide any " 438 "identity"); 439 goto failed; 440 } 441 442 new_identity = os_malloc(attr->identity_len); 443 if (new_identity == NULL) 444 goto failed; 445 os_free(sm->identity); 446 sm->identity = new_identity; 447 os_memcpy(sm->identity, attr->identity, attr->identity_len); 448 sm->identity_len = attr->identity_len; 449 450 wpa_hexdump_ascii(MSG_DEBUG, "EAP-SIM: Identity", 451 sm->identity, sm->identity_len); 452 username = sim_get_username(sm->identity, sm->identity_len); 453 if (username == NULL) 454 goto failed; 455 456 if (username[0] == EAP_SIM_REAUTH_ID_PREFIX) { 457 wpa_printf(MSG_DEBUG, "EAP-SIM: Reauth username '%s'", 458 username); 459 data->reauth = eap_sim_db_get_reauth_entry( 460 sm->eap_sim_db_priv, username); 461 os_free(username); 462 if (data->reauth == NULL) { 463 wpa_printf(MSG_DEBUG, "EAP-SIM: Unknown reauth " 464 "identity - request full auth identity"); 465 /* Remain in START state for another round */ 466 return; 467 } 468 wpa_printf(MSG_DEBUG, "EAP-SIM: Using fast re-authentication"); 469 os_strlcpy(data->permanent, data->reauth->permanent, 470 sizeof(data->permanent)); 471 data->counter = data->reauth->counter; 472 os_memcpy(data->mk, data->reauth->mk, EAP_SIM_MK_LEN); 473 eap_sim_state(data, REAUTH); 474 return; 475 } 476 477 if (username[0] == EAP_SIM_PSEUDONYM_PREFIX) { 478 const char *permanent; 479 wpa_printf(MSG_DEBUG, "EAP-SIM: Pseudonym username '%s'", 480 username); 481 permanent = eap_sim_db_get_permanent( 482 sm->eap_sim_db_priv, username); 483 os_free(username); 484 if (permanent == NULL) { 485 wpa_printf(MSG_DEBUG, "EAP-SIM: Unknown pseudonym " 486 "identity - request permanent identity"); 487 /* Remain in START state for another round */ 488 return; 489 } 490 os_strlcpy(data->permanent, permanent, 491 sizeof(data->permanent)); 492 } else if (username[0] == EAP_SIM_PERMANENT_PREFIX) { 493 wpa_printf(MSG_DEBUG, "EAP-SIM: Permanent username '%s'", 494 username); 495 os_strlcpy(data->permanent, username, sizeof(data->permanent)); 496 os_free(username); 497 } else { 498 wpa_printf(MSG_DEBUG, "EAP-SIM: Unrecognized username '%s'", 499 username); 500 os_free(username); 501 goto failed; 502 } 503 504 skip_id_update: 505 /* Full authentication */ 506 507 if (attr->nonce_mt == NULL || attr->selected_version < 0) { 508 wpa_printf(MSG_DEBUG, "EAP-SIM: Start/Response missing " 509 "required attributes"); 510 goto failed; 511 } 512 513 if (!eap_sim_supported_ver(data, attr->selected_version)) { 514 wpa_printf(MSG_DEBUG, "EAP-SIM: Peer selected unsupported " 515 "version %d", attr->selected_version); 516 goto failed; 517 } 518 519 data->counter = 0; /* reset re-auth counter since this is full auth */ 520 data->reauth = NULL; 521 522 data->num_chal = eap_sim_db_get_gsm_triplets( 523 sm->eap_sim_db_priv, data->permanent, EAP_SIM_MAX_CHAL, 524 (u8 *) data->rand, (u8 *) data->kc, (u8 *) data->sres, sm); 525 if (data->num_chal == EAP_SIM_DB_PENDING) { 526 wpa_printf(MSG_DEBUG, "EAP-SIM: GSM authentication triplets " 527 "not yet available - pending request"); 528 sm->method_pending = METHOD_PENDING_WAIT; 529 return; 530 } 531 if (data->num_chal < 2) { 532 wpa_printf(MSG_INFO, "EAP-SIM: Failed to get GSM " 533 "authentication triplets for the peer"); 534 goto failed; 535 } 536 537 identity_len = sm->identity_len; 538 while (identity_len > 0 && sm->identity[identity_len - 1] == '\0') { 539 wpa_printf(MSG_DEBUG, "EAP-SIM: Workaround - drop last null " 540 "character from identity"); 541 identity_len--; 542 } 543 wpa_hexdump_ascii(MSG_DEBUG, "EAP-SIM: Identity for MK derivation", 544 sm->identity, identity_len); 545 546 os_memcpy(data->nonce_mt, attr->nonce_mt, EAP_SIM_NONCE_MT_LEN); 547 WPA_PUT_BE16(ver_list, EAP_SIM_VERSION); 548 eap_sim_derive_mk(sm->identity, identity_len, attr->nonce_mt, 549 attr->selected_version, ver_list, sizeof(ver_list), 550 data->num_chal, (const u8 *) data->kc, data->mk); 551 eap_sim_derive_keys(data->mk, data->k_encr, data->k_aut, data->msk, 552 data->emsk); 553 554 eap_sim_state(data, CHALLENGE); 555 return; 556 557 failed: 558 data->notification = EAP_SIM_GENERAL_FAILURE_BEFORE_AUTH; 559 eap_sim_state(data, NOTIFICATION); 560 } 561 562 563 static void eap_sim_process_challenge(struct eap_sm *sm, 564 struct eap_sim_data *data, 565 struct wpabuf *respData, 566 struct eap_sim_attrs *attr) 567 { 568 if (attr->mac == NULL || 569 eap_sim_verify_mac(data->k_aut, respData, attr->mac, 570 (u8 *) data->sres, 571 data->num_chal * EAP_SIM_SRES_LEN)) { 572 wpa_printf(MSG_WARNING, "EAP-SIM: Challenge message " 573 "did not include valid AT_MAC"); 574 data->notification = EAP_SIM_GENERAL_FAILURE_BEFORE_AUTH; 575 eap_sim_state(data, NOTIFICATION); 576 return; 577 } 578 579 wpa_printf(MSG_DEBUG, "EAP-SIM: Challenge response includes the " 580 "correct AT_MAC"); 581 if (sm->eap_sim_aka_result_ind && attr->result_ind) { 582 data->use_result_ind = 1; 583 data->notification = EAP_SIM_SUCCESS; 584 eap_sim_state(data, NOTIFICATION); 585 } else 586 eap_sim_state(data, SUCCESS); 587 588 if (data->next_pseudonym) { 589 eap_sim_db_add_pseudonym(sm->eap_sim_db_priv, data->permanent, 590 data->next_pseudonym); 591 data->next_pseudonym = NULL; 592 } 593 if (data->next_reauth_id) { 594 eap_sim_db_add_reauth(sm->eap_sim_db_priv, data->permanent, 595 data->next_reauth_id, data->counter + 1, 596 data->mk); 597 data->next_reauth_id = NULL; 598 } 599 } 600 601 602 static void eap_sim_process_reauth(struct eap_sm *sm, 603 struct eap_sim_data *data, 604 struct wpabuf *respData, 605 struct eap_sim_attrs *attr) 606 { 607 struct eap_sim_attrs eattr; 608 u8 *decrypted = NULL; 609 610 if (attr->mac == NULL || 611 eap_sim_verify_mac(data->k_aut, respData, attr->mac, data->nonce_s, 612 EAP_SIM_NONCE_S_LEN)) { 613 wpa_printf(MSG_WARNING, "EAP-SIM: Re-authentication message " 614 "did not include valid AT_MAC"); 615 goto fail; 616 } 617 618 if (attr->encr_data == NULL || attr->iv == NULL) { 619 wpa_printf(MSG_WARNING, "EAP-SIM: Reauthentication " 620 "message did not include encrypted data"); 621 goto fail; 622 } 623 624 decrypted = eap_sim_parse_encr(data->k_encr, attr->encr_data, 625 attr->encr_data_len, attr->iv, &eattr, 626 0); 627 if (decrypted == NULL) { 628 wpa_printf(MSG_WARNING, "EAP-SIM: Failed to parse encrypted " 629 "data from reauthentication message"); 630 goto fail; 631 } 632 633 if (eattr.counter != data->counter) { 634 wpa_printf(MSG_WARNING, "EAP-SIM: Re-authentication message " 635 "used incorrect counter %u, expected %u", 636 eattr.counter, data->counter); 637 goto fail; 638 } 639 os_free(decrypted); 640 decrypted = NULL; 641 642 wpa_printf(MSG_DEBUG, "EAP-SIM: Re-authentication response includes " 643 "the correct AT_MAC"); 644 645 if (eattr.counter_too_small) { 646 wpa_printf(MSG_DEBUG, "EAP-AKA: Re-authentication response " 647 "included AT_COUNTER_TOO_SMALL - starting full " 648 "authentication"); 649 data->start_round = -1; 650 eap_sim_state(data, START); 651 return; 652 } 653 654 if (sm->eap_sim_aka_result_ind && attr->result_ind) { 655 data->use_result_ind = 1; 656 data->notification = EAP_SIM_SUCCESS; 657 eap_sim_state(data, NOTIFICATION); 658 } else 659 eap_sim_state(data, SUCCESS); 660 661 if (data->next_reauth_id) { 662 eap_sim_db_add_reauth(sm->eap_sim_db_priv, data->permanent, 663 data->next_reauth_id, 664 data->counter + 1, data->mk); 665 data->next_reauth_id = NULL; 666 } else { 667 eap_sim_db_remove_reauth(sm->eap_sim_db_priv, data->reauth); 668 data->reauth = NULL; 669 } 670 671 return; 672 673 fail: 674 data->notification = EAP_SIM_GENERAL_FAILURE_BEFORE_AUTH; 675 eap_sim_state(data, NOTIFICATION); 676 eap_sim_db_remove_reauth(sm->eap_sim_db_priv, data->reauth); 677 data->reauth = NULL; 678 os_free(decrypted); 679 } 680 681 682 static void eap_sim_process_client_error(struct eap_sm *sm, 683 struct eap_sim_data *data, 684 struct wpabuf *respData, 685 struct eap_sim_attrs *attr) 686 { 687 wpa_printf(MSG_DEBUG, "EAP-SIM: Client reported error %d", 688 attr->client_error_code); 689 if (data->notification == EAP_SIM_SUCCESS && data->use_result_ind) 690 eap_sim_state(data, SUCCESS); 691 else 692 eap_sim_state(data, FAILURE); 693 } 694 695 696 static void eap_sim_process_notification(struct eap_sm *sm, 697 struct eap_sim_data *data, 698 struct wpabuf *respData, 699 struct eap_sim_attrs *attr) 700 { 701 wpa_printf(MSG_DEBUG, "EAP-SIM: Client replied to notification"); 702 if (data->notification == EAP_SIM_SUCCESS && data->use_result_ind) 703 eap_sim_state(data, SUCCESS); 704 else 705 eap_sim_state(data, FAILURE); 706 } 707 708 709 static void eap_sim_process(struct eap_sm *sm, void *priv, 710 struct wpabuf *respData) 711 { 712 struct eap_sim_data *data = priv; 713 const u8 *pos, *end; 714 u8 subtype; 715 size_t len; 716 struct eap_sim_attrs attr; 717 718 pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_SIM, respData, &len); 719 if (pos == NULL || len < 3) 720 return; 721 722 end = pos + len; 723 subtype = *pos; 724 pos += 3; 725 726 if (eap_sim_unexpected_subtype(data, subtype)) { 727 wpa_printf(MSG_DEBUG, "EAP-SIM: Unrecognized or unexpected " 728 "EAP-SIM Subtype in EAP Response"); 729 data->notification = EAP_SIM_GENERAL_FAILURE_BEFORE_AUTH; 730 eap_sim_state(data, NOTIFICATION); 731 return; 732 } 733 734 if (eap_sim_parse_attr(pos, end, &attr, 0, 0)) { 735 wpa_printf(MSG_DEBUG, "EAP-SIM: Failed to parse attributes"); 736 if (subtype != EAP_SIM_SUBTYPE_CLIENT_ERROR && 737 (data->state == START || data->state == CHALLENGE || 738 data->state == REAUTH)) { 739 data->notification = 740 EAP_SIM_GENERAL_FAILURE_BEFORE_AUTH; 741 eap_sim_state(data, NOTIFICATION); 742 return; 743 } 744 eap_sim_state(data, FAILURE); 745 return; 746 } 747 748 if (subtype == EAP_SIM_SUBTYPE_CLIENT_ERROR) { 749 eap_sim_process_client_error(sm, data, respData, &attr); 750 return; 751 } 752 753 switch (data->state) { 754 case START: 755 eap_sim_process_start(sm, data, respData, &attr); 756 break; 757 case CHALLENGE: 758 eap_sim_process_challenge(sm, data, respData, &attr); 759 break; 760 case REAUTH: 761 eap_sim_process_reauth(sm, data, respData, &attr); 762 break; 763 case NOTIFICATION: 764 eap_sim_process_notification(sm, data, respData, &attr); 765 break; 766 default: 767 wpa_printf(MSG_DEBUG, "EAP-SIM: Unknown state %d in " 768 "process", data->state); 769 break; 770 } 771 } 772 773 774 static Boolean eap_sim_isDone(struct eap_sm *sm, void *priv) 775 { 776 struct eap_sim_data *data = priv; 777 return data->state == SUCCESS || data->state == FAILURE; 778 } 779 780 781 static u8 * eap_sim_getKey(struct eap_sm *sm, void *priv, size_t *len) 782 { 783 struct eap_sim_data *data = priv; 784 u8 *key; 785 786 if (data->state != SUCCESS) 787 return NULL; 788 789 key = os_malloc(EAP_SIM_KEYING_DATA_LEN); 790 if (key == NULL) 791 return NULL; 792 os_memcpy(key, data->msk, EAP_SIM_KEYING_DATA_LEN); 793 *len = EAP_SIM_KEYING_DATA_LEN; 794 return key; 795 } 796 797 798 static u8 * eap_sim_get_emsk(struct eap_sm *sm, void *priv, size_t *len) 799 { 800 struct eap_sim_data *data = priv; 801 u8 *key; 802 803 if (data->state != SUCCESS) 804 return NULL; 805 806 key = os_malloc(EAP_EMSK_LEN); 807 if (key == NULL) 808 return NULL; 809 os_memcpy(key, data->emsk, EAP_EMSK_LEN); 810 *len = EAP_EMSK_LEN; 811 return key; 812 } 813 814 815 static Boolean eap_sim_isSuccess(struct eap_sm *sm, void *priv) 816 { 817 struct eap_sim_data *data = priv; 818 return data->state == SUCCESS; 819 } 820 821 822 int eap_server_sim_register(void) 823 { 824 struct eap_method *eap; 825 int ret; 826 827 eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION, 828 EAP_VENDOR_IETF, EAP_TYPE_SIM, "SIM"); 829 if (eap == NULL) 830 return -1; 831 832 eap->init = eap_sim_init; 833 eap->reset = eap_sim_reset; 834 eap->buildReq = eap_sim_buildReq; 835 eap->check = eap_sim_check; 836 eap->process = eap_sim_process; 837 eap->isDone = eap_sim_isDone; 838 eap->getKey = eap_sim_getKey; 839 eap->isSuccess = eap_sim_isSuccess; 840 eap->get_emsk = eap_sim_get_emsk; 841 842 ret = eap_server_method_register(eap); 843 if (ret) 844 eap_server_method_free(eap); 845 return ret; 846 } 847
