1 /* 2 * Wi-Fi Protected Setup 3 * Copyright (c) 2007-2009, Jouni Malinen <j@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/dh_group5.h" 13 #include "common/ieee802_11_defs.h" 14 #include "wps_i.h" 15 #include "wps_dev_attr.h" 16 17 18 #ifdef CONFIG_WPS_TESTING 19 int wps_version_number = 0x20; 20 int wps_testing_stub_cred = 0; 21 int wps_corrupt_pkhash = 0; 22 int wps_force_auth_types_in_use = 0; 23 u16 wps_force_auth_types = 0; 24 int wps_force_encr_types_in_use = 0; 25 u16 wps_force_encr_types = 0; 26 #endif /* CONFIG_WPS_TESTING */ 27 28 29 /** 30 * wps_init - Initialize WPS Registration protocol data 31 * @cfg: WPS configuration 32 * Returns: Pointer to allocated data or %NULL on failure 33 * 34 * This function is used to initialize WPS data for a registration protocol 35 * instance (i.e., each run of registration protocol as a Registrar of 36 * Enrollee. The caller is responsible for freeing this data after the 37 * registration run has been completed by calling wps_deinit(). 38 */ 39 struct wps_data * wps_init(const struct wps_config *cfg) 40 { 41 struct wps_data *data = os_zalloc(sizeof(*data)); 42 if (data == NULL) 43 return NULL; 44 data->wps = cfg->wps; 45 data->registrar = cfg->registrar; 46 if (cfg->registrar) { 47 os_memcpy(data->uuid_r, cfg->wps->uuid, WPS_UUID_LEN); 48 } else { 49 os_memcpy(data->mac_addr_e, cfg->wps->dev.mac_addr, ETH_ALEN); 50 os_memcpy(data->uuid_e, cfg->wps->uuid, WPS_UUID_LEN); 51 } 52 if (cfg->pin) { 53 data->dev_pw_id = cfg->dev_pw_id; 54 data->dev_password = os_memdup(cfg->pin, cfg->pin_len); 55 if (data->dev_password == NULL) { 56 os_free(data); 57 return NULL; 58 } 59 data->dev_password_len = cfg->pin_len; 60 wpa_hexdump_key(MSG_DEBUG, "WPS: AP PIN dev_password", 61 data->dev_password, data->dev_password_len); 62 } 63 64 #ifdef CONFIG_WPS_NFC 65 if (cfg->pin == NULL && 66 cfg->dev_pw_id == DEV_PW_NFC_CONNECTION_HANDOVER) 67 data->dev_pw_id = cfg->dev_pw_id; 68 69 if (cfg->wps->ap && !cfg->registrar && cfg->wps->ap_nfc_dev_pw_id) { 70 /* Keep AP PIN as alternative Device Password */ 71 data->alt_dev_pw_id = data->dev_pw_id; 72 data->alt_dev_password = data->dev_password; 73 data->alt_dev_password_len = data->dev_password_len; 74 75 data->dev_pw_id = cfg->wps->ap_nfc_dev_pw_id; 76 data->dev_password = 77 os_memdup(wpabuf_head(cfg->wps->ap_nfc_dev_pw), 78 wpabuf_len(cfg->wps->ap_nfc_dev_pw)); 79 if (data->dev_password == NULL) { 80 os_free(data); 81 return NULL; 82 } 83 data->dev_password_len = wpabuf_len(cfg->wps->ap_nfc_dev_pw); 84 wpa_hexdump_key(MSG_DEBUG, "WPS: NFC dev_password", 85 data->dev_password, data->dev_password_len); 86 } 87 #endif /* CONFIG_WPS_NFC */ 88 89 data->pbc = cfg->pbc; 90 if (cfg->pbc) { 91 /* Use special PIN '00000000' for PBC */ 92 data->dev_pw_id = DEV_PW_PUSHBUTTON; 93 bin_clear_free(data->dev_password, data->dev_password_len); 94 data->dev_password = (u8 *) os_strdup("00000000"); 95 if (data->dev_password == NULL) { 96 os_free(data); 97 return NULL; 98 } 99 data->dev_password_len = 8; 100 } 101 102 data->state = data->registrar ? RECV_M1 : SEND_M1; 103 104 if (cfg->assoc_wps_ie) { 105 struct wps_parse_attr attr; 106 wpa_hexdump_buf(MSG_DEBUG, "WPS: WPS IE from (Re)AssocReq", 107 cfg->assoc_wps_ie); 108 if (wps_parse_msg(cfg->assoc_wps_ie, &attr) < 0) { 109 wpa_printf(MSG_DEBUG, "WPS: Failed to parse WPS IE " 110 "from (Re)AssocReq"); 111 } else if (attr.request_type == NULL) { 112 wpa_printf(MSG_DEBUG, "WPS: No Request Type attribute " 113 "in (Re)AssocReq WPS IE"); 114 } else { 115 wpa_printf(MSG_DEBUG, "WPS: Request Type (from WPS IE " 116 "in (Re)AssocReq WPS IE): %d", 117 *attr.request_type); 118 data->request_type = *attr.request_type; 119 } 120 } 121 122 if (cfg->new_ap_settings) { 123 data->new_ap_settings = 124 os_memdup(cfg->new_ap_settings, 125 sizeof(*data->new_ap_settings)); 126 if (data->new_ap_settings == NULL) { 127 bin_clear_free(data->dev_password, 128 data->dev_password_len); 129 os_free(data); 130 return NULL; 131 } 132 } 133 134 if (cfg->peer_addr) 135 os_memcpy(data->peer_dev.mac_addr, cfg->peer_addr, ETH_ALEN); 136 if (cfg->p2p_dev_addr) 137 os_memcpy(data->p2p_dev_addr, cfg->p2p_dev_addr, ETH_ALEN); 138 139 data->use_psk_key = cfg->use_psk_key; 140 data->pbc_in_m1 = cfg->pbc_in_m1; 141 142 if (cfg->peer_pubkey_hash) { 143 os_memcpy(data->peer_pubkey_hash, cfg->peer_pubkey_hash, 144 WPS_OOB_PUBKEY_HASH_LEN); 145 data->peer_pubkey_hash_set = 1; 146 } 147 148 data->multi_ap_backhaul_sta = cfg->multi_ap_backhaul_sta; 149 data->multi_ap_profile = cfg->multi_ap_profile; 150 151 return data; 152 } 153 154 155 /** 156 * wps_deinit - Deinitialize WPS Registration protocol data 157 * @data: WPS Registration protocol data from wps_init() 158 */ 159 void wps_deinit(struct wps_data *data) 160 { 161 #ifdef CONFIG_WPS_NFC 162 if (data->registrar && data->nfc_pw_token) 163 wps_registrar_remove_nfc_pw_token(data->wps->registrar, 164 data->nfc_pw_token); 165 #endif /* CONFIG_WPS_NFC */ 166 167 if (data->wps_pin_revealed) { 168 wpa_printf(MSG_DEBUG, "WPS: Full PIN information revealed and " 169 "negotiation failed"); 170 if (data->registrar) 171 wps_registrar_invalidate_pin(data->wps->registrar, 172 data->uuid_e); 173 } else if (data->registrar) 174 wps_registrar_unlock_pin(data->wps->registrar, data->uuid_e); 175 176 wpabuf_clear_free(data->dh_privkey); 177 wpabuf_free(data->dh_pubkey_e); 178 wpabuf_free(data->dh_pubkey_r); 179 wpabuf_free(data->last_msg); 180 bin_clear_free(data->dev_password, data->dev_password_len); 181 bin_clear_free(data->alt_dev_password, data->alt_dev_password_len); 182 bin_clear_free(data->new_psk, data->new_psk_len); 183 wps_device_data_free(&data->peer_dev); 184 bin_clear_free(data->new_ap_settings, sizeof(*data->new_ap_settings)); 185 dh5_free(data->dh_ctx); 186 os_free(data); 187 } 188 189 190 /** 191 * wps_process_msg - Process a WPS message 192 * @wps: WPS Registration protocol data from wps_init() 193 * @op_code: Message OP Code 194 * @msg: Message data 195 * Returns: Processing result 196 * 197 * This function is used to process WPS messages with OP Codes WSC_ACK, 198 * WSC_NACK, WSC_MSG, and WSC_Done. The caller (e.g., EAP server/peer) is 199 * responsible for reassembling the messages before calling this function. 200 * Response to this message is built by calling wps_get_msg(). 201 */ 202 enum wps_process_res wps_process_msg(struct wps_data *wps, 203 enum wsc_op_code op_code, 204 const struct wpabuf *msg) 205 { 206 if (wps->registrar) 207 return wps_registrar_process_msg(wps, op_code, msg); 208 else 209 return wps_enrollee_process_msg(wps, op_code, msg); 210 } 211 212 213 /** 214 * wps_get_msg - Build a WPS message 215 * @wps: WPS Registration protocol data from wps_init() 216 * @op_code: Buffer for returning message OP Code 217 * Returns: The generated WPS message or %NULL on failure 218 * 219 * This function is used to build a response to a message processed by calling 220 * wps_process_msg(). The caller is responsible for freeing the buffer. 221 */ 222 struct wpabuf * wps_get_msg(struct wps_data *wps, enum wsc_op_code *op_code) 223 { 224 if (wps->registrar) 225 return wps_registrar_get_msg(wps, op_code); 226 else 227 return wps_enrollee_get_msg(wps, op_code); 228 } 229 230 231 /** 232 * wps_is_selected_pbc_registrar - Check whether WPS IE indicates active PBC 233 * @msg: WPS IE contents from Beacon or Probe Response frame 234 * Returns: 1 if PBC Registrar is active, 0 if not 235 */ 236 int wps_is_selected_pbc_registrar(const struct wpabuf *msg) 237 { 238 struct wps_parse_attr attr; 239 240 /* 241 * In theory, this could also verify that attr.sel_reg_config_methods 242 * includes WPS_CONFIG_PUSHBUTTON, but some deployed AP implementations 243 * do not set Selected Registrar Config Methods attribute properly, so 244 * it is safer to just use Device Password ID here. 245 */ 246 247 if (wps_parse_msg(msg, &attr) < 0 || 248 !attr.selected_registrar || *attr.selected_registrar == 0 || 249 !attr.dev_password_id || 250 WPA_GET_BE16(attr.dev_password_id) != DEV_PW_PUSHBUTTON) 251 return 0; 252 253 #ifdef CONFIG_WPS_STRICT 254 if (!attr.sel_reg_config_methods || 255 !(WPA_GET_BE16(attr.sel_reg_config_methods) & 256 WPS_CONFIG_PUSHBUTTON)) 257 return 0; 258 #endif /* CONFIG_WPS_STRICT */ 259 260 return 1; 261 } 262 263 264 static int is_selected_pin_registrar(struct wps_parse_attr *attr) 265 { 266 /* 267 * In theory, this could also verify that attr.sel_reg_config_methods 268 * includes WPS_CONFIG_LABEL, WPS_CONFIG_DISPLAY, or WPS_CONFIG_KEYPAD, 269 * but some deployed AP implementations do not set Selected Registrar 270 * Config Methods attribute properly, so it is safer to just use 271 * Device Password ID here. 272 */ 273 274 if (!attr->selected_registrar || *attr->selected_registrar == 0) 275 return 0; 276 277 if (attr->dev_password_id != NULL && 278 WPA_GET_BE16(attr->dev_password_id) == DEV_PW_PUSHBUTTON) 279 return 0; 280 281 #ifdef CONFIG_WPS_STRICT 282 if (!attr->sel_reg_config_methods || 283 !(WPA_GET_BE16(attr->sel_reg_config_methods) & 284 (WPS_CONFIG_LABEL | WPS_CONFIG_DISPLAY | WPS_CONFIG_KEYPAD))) 285 return 0; 286 #endif /* CONFIG_WPS_STRICT */ 287 288 return 1; 289 } 290 291 292 /** 293 * wps_is_selected_pin_registrar - Check whether WPS IE indicates active PIN 294 * @msg: WPS IE contents from Beacon or Probe Response frame 295 * Returns: 1 if PIN Registrar is active, 0 if not 296 */ 297 int wps_is_selected_pin_registrar(const struct wpabuf *msg) 298 { 299 struct wps_parse_attr attr; 300 301 if (wps_parse_msg(msg, &attr) < 0) 302 return 0; 303 304 return is_selected_pin_registrar(&attr); 305 } 306 307 308 /** 309 * wps_is_addr_authorized - Check whether WPS IE authorizes MAC address 310 * @msg: WPS IE contents from Beacon or Probe Response frame 311 * @addr: MAC address to search for 312 * @ver1_compat: Whether to use version 1 compatibility mode 313 * Returns: 2 if the specified address is explicit authorized, 1 if address is 314 * authorized (broadcast), 0 if not 315 */ 316 int wps_is_addr_authorized(const struct wpabuf *msg, const u8 *addr, 317 int ver1_compat) 318 { 319 struct wps_parse_attr attr; 320 unsigned int i; 321 const u8 *pos; 322 const u8 bcast[ETH_ALEN] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }; 323 324 if (wps_parse_msg(msg, &attr) < 0) 325 return 0; 326 327 if (!attr.version2 && ver1_compat) { 328 /* 329 * Version 1.0 AP - AuthorizedMACs not used, so revert back to 330 * old mechanism of using SelectedRegistrar. 331 */ 332 return is_selected_pin_registrar(&attr); 333 } 334 335 if (!attr.authorized_macs) 336 return 0; 337 338 pos = attr.authorized_macs; 339 for (i = 0; i < attr.authorized_macs_len / ETH_ALEN; i++) { 340 if (ether_addr_equal(pos, addr)) 341 return 2; 342 if (ether_addr_equal(pos, bcast)) 343 return 1; 344 pos += ETH_ALEN; 345 } 346 347 return 0; 348 } 349 350 351 /** 352 * wps_ap_priority_compar - Prioritize WPS IE from two APs 353 * @wps_a: WPS IE contents from Beacon or Probe Response frame 354 * @wps_b: WPS IE contents from Beacon or Probe Response frame 355 * Returns: 1 if wps_b is considered more likely selection for WPS 356 * provisioning, -1 if wps_a is considered more like, or 0 if no preference 357 */ 358 int wps_ap_priority_compar(const struct wpabuf *wps_a, 359 const struct wpabuf *wps_b) 360 { 361 struct wps_parse_attr attr; 362 int sel_a, sel_b; 363 364 if (wps_a == NULL || wps_parse_msg(wps_a, &attr) < 0) 365 return 1; 366 sel_a = attr.selected_registrar && *attr.selected_registrar != 0; 367 368 if (wps_b == NULL || wps_parse_msg(wps_b, &attr) < 0) 369 return -1; 370 sel_b = attr.selected_registrar && *attr.selected_registrar != 0; 371 372 if (sel_a && !sel_b) 373 return -1; 374 if (!sel_a && sel_b) 375 return 1; 376 377 return 0; 378 } 379 380 381 /** 382 * wps_get_uuid_e - Get UUID-E from WPS IE 383 * @msg: WPS IE contents from Beacon or Probe Response frame 384 * Returns: Pointer to UUID-E or %NULL if not included 385 * 386 * The returned pointer is to the msg contents and it remains valid only as 387 * long as the msg buffer is valid. 388 */ 389 const u8 * wps_get_uuid_e(const struct wpabuf *msg) 390 { 391 struct wps_parse_attr attr; 392 393 if (wps_parse_msg(msg, &attr) < 0) 394 return NULL; 395 return attr.uuid_e; 396 } 397 398 399 /** 400 * wps_is_20 - Check whether WPS attributes claim support for WPS 2.0 401 */ 402 int wps_is_20(const struct wpabuf *msg) 403 { 404 struct wps_parse_attr attr; 405 406 if (msg == NULL || wps_parse_msg(msg, &attr) < 0) 407 return 0; 408 return attr.version2 != NULL; 409 } 410 411 412 /** 413 * wps_build_assoc_req_ie - Build WPS IE for (Re)Association Request 414 * @req_type: Value for Request Type attribute 415 * Returns: WPS IE or %NULL on failure 416 * 417 * The caller is responsible for freeing the buffer. 418 */ 419 struct wpabuf * wps_build_assoc_req_ie(enum wps_request_type req_type) 420 { 421 struct wpabuf *ie; 422 u8 *len; 423 424 wpa_printf(MSG_DEBUG, "WPS: Building WPS IE for (Re)Association " 425 "Request"); 426 ie = wpabuf_alloc(100); 427 if (ie == NULL) 428 return NULL; 429 430 wpabuf_put_u8(ie, WLAN_EID_VENDOR_SPECIFIC); 431 len = wpabuf_put(ie, 1); 432 wpabuf_put_be32(ie, WPS_DEV_OUI_WFA); 433 434 if (wps_build_version(ie) || 435 wps_build_req_type(ie, req_type) || 436 wps_build_wfa_ext(ie, 0, NULL, 0, 0)) { 437 wpabuf_free(ie); 438 return NULL; 439 } 440 441 *len = wpabuf_len(ie) - 2; 442 443 return ie; 444 } 445 446 447 /** 448 * wps_build_assoc_resp_ie - Build WPS IE for (Re)Association Response 449 * Returns: WPS IE or %NULL on failure 450 * 451 * The caller is responsible for freeing the buffer. 452 */ 453 struct wpabuf * wps_build_assoc_resp_ie(void) 454 { 455 struct wpabuf *ie; 456 u8 *len; 457 458 wpa_printf(MSG_DEBUG, "WPS: Building WPS IE for (Re)Association " 459 "Response"); 460 ie = wpabuf_alloc(100); 461 if (ie == NULL) 462 return NULL; 463 464 wpabuf_put_u8(ie, WLAN_EID_VENDOR_SPECIFIC); 465 len = wpabuf_put(ie, 1); 466 wpabuf_put_be32(ie, WPS_DEV_OUI_WFA); 467 468 if (wps_build_version(ie) || 469 wps_build_resp_type(ie, WPS_RESP_AP) || 470 wps_build_wfa_ext(ie, 0, NULL, 0, 0)) { 471 wpabuf_free(ie); 472 return NULL; 473 } 474 475 *len = wpabuf_len(ie) - 2; 476 477 return ie; 478 } 479 480 481 /** 482 * wps_build_probe_req_ie - Build WPS IE for Probe Request 483 * @pw_id: Password ID (DEV_PW_PUSHBUTTON for active PBC and DEV_PW_DEFAULT for 484 * most other use cases) 485 * @dev: Device attributes 486 * @uuid: Own UUID 487 * @req_type: Value for Request Type attribute 488 * @num_req_dev_types: Number of requested device types 489 * @req_dev_types: Requested device types (8 * num_req_dev_types octets) or 490 * %NULL if none 491 * Returns: WPS IE or %NULL on failure 492 * 493 * The caller is responsible for freeing the buffer. 494 */ 495 struct wpabuf * wps_build_probe_req_ie(u16 pw_id, struct wps_device_data *dev, 496 const u8 *uuid, 497 enum wps_request_type req_type, 498 unsigned int num_req_dev_types, 499 const u8 *req_dev_types) 500 { 501 struct wpabuf *ie; 502 503 wpa_printf(MSG_DEBUG, "WPS: Building WPS IE for Probe Request"); 504 505 ie = wpabuf_alloc(500); 506 if (ie == NULL) 507 return NULL; 508 509 if (wps_build_version(ie) || 510 wps_build_req_type(ie, req_type) || 511 wps_build_config_methods(ie, dev->config_methods) || 512 wps_build_uuid_e(ie, uuid) || 513 wps_build_primary_dev_type(dev, ie) || 514 wps_build_rf_bands(dev, ie, 0) || 515 wps_build_assoc_state(NULL, ie) || 516 wps_build_config_error(ie, WPS_CFG_NO_ERROR) || 517 wps_build_dev_password_id(ie, pw_id) || 518 wps_build_manufacturer(dev, ie) || 519 wps_build_model_name(dev, ie) || 520 wps_build_model_number(dev, ie) || 521 wps_build_dev_name(dev, ie) || 522 wps_build_wfa_ext(ie, req_type == WPS_REQ_ENROLLEE, NULL, 0, 0) || 523 wps_build_req_dev_type(dev, ie, num_req_dev_types, req_dev_types) 524 || 525 wps_build_secondary_dev_type(dev, ie) 526 ) { 527 wpabuf_free(ie); 528 return NULL; 529 } 530 531 return wps_ie_encapsulate(ie); 532 } 533 534 535 void wps_free_pending_msgs(struct upnp_pending_message *msgs) 536 { 537 struct upnp_pending_message *p, *prev; 538 p = msgs; 539 while (p) { 540 prev = p; 541 p = p->next; 542 wpabuf_free(prev->msg); 543 os_free(prev); 544 } 545 } 546 547 548 int wps_attr_text(struct wpabuf *data, char *buf, char *end) 549 { 550 struct wps_parse_attr attr; 551 char *pos = buf; 552 int ret; 553 554 if (wps_parse_msg(data, &attr) < 0) 555 return -1; 556 557 if (attr.wps_state) { 558 if (*attr.wps_state == WPS_STATE_NOT_CONFIGURED) 559 ret = os_snprintf(pos, end - pos, 560 "wps_state=unconfigured\n"); 561 else if (*attr.wps_state == WPS_STATE_CONFIGURED) 562 ret = os_snprintf(pos, end - pos, 563 "wps_state=configured\n"); 564 else 565 ret = 0; 566 if (os_snprintf_error(end - pos, ret)) 567 return pos - buf; 568 pos += ret; 569 } 570 571 if (attr.ap_setup_locked && *attr.ap_setup_locked) { 572 ret = os_snprintf(pos, end - pos, 573 "wps_ap_setup_locked=1\n"); 574 if (os_snprintf_error(end - pos, ret)) 575 return pos - buf; 576 pos += ret; 577 } 578 579 if (attr.selected_registrar && *attr.selected_registrar) { 580 ret = os_snprintf(pos, end - pos, 581 "wps_selected_registrar=1\n"); 582 if (os_snprintf_error(end - pos, ret)) 583 return pos - buf; 584 pos += ret; 585 } 586 587 if (attr.dev_password_id) { 588 ret = os_snprintf(pos, end - pos, 589 "wps_device_password_id=%u\n", 590 WPA_GET_BE16(attr.dev_password_id)); 591 if (os_snprintf_error(end - pos, ret)) 592 return pos - buf; 593 pos += ret; 594 } 595 596 if (attr.sel_reg_config_methods) { 597 ret = os_snprintf(pos, end - pos, 598 "wps_selected_registrar_config_methods=" 599 "0x%04x\n", 600 WPA_GET_BE16(attr.sel_reg_config_methods)); 601 if (os_snprintf_error(end - pos, ret)) 602 return pos - buf; 603 pos += ret; 604 } 605 606 if (attr.primary_dev_type) { 607 char devtype[WPS_DEV_TYPE_BUFSIZE]; 608 ret = os_snprintf(pos, end - pos, 609 "wps_primary_device_type=%s\n", 610 wps_dev_type_bin2str(attr.primary_dev_type, 611 devtype, 612 sizeof(devtype))); 613 if (os_snprintf_error(end - pos, ret)) 614 return pos - buf; 615 pos += ret; 616 } 617 618 if (attr.dev_name) { 619 char *str = os_malloc(attr.dev_name_len + 1); 620 size_t i; 621 if (str == NULL) 622 return pos - buf; 623 for (i = 0; i < attr.dev_name_len; i++) { 624 if (attr.dev_name[i] == 0 || 625 is_ctrl_char(attr.dev_name[i])) 626 str[i] = '_'; 627 else 628 str[i] = attr.dev_name[i]; 629 } 630 str[i] = '\0'; 631 ret = os_snprintf(pos, end - pos, "wps_device_name=%s\n", str); 632 os_free(str); 633 if (os_snprintf_error(end - pos, ret)) 634 return pos - buf; 635 pos += ret; 636 } 637 638 if (attr.config_methods) { 639 ret = os_snprintf(pos, end - pos, 640 "wps_config_methods=0x%04x\n", 641 WPA_GET_BE16(attr.config_methods)); 642 if (os_snprintf_error(end - pos, ret)) 643 return pos - buf; 644 pos += ret; 645 } 646 647 return pos - buf; 648 } 649 650 651 const char * wps_ei_str(enum wps_error_indication ei) 652 { 653 switch (ei) { 654 case WPS_EI_NO_ERROR: 655 return "No Error"; 656 case WPS_EI_SECURITY_TKIP_ONLY_PROHIBITED: 657 return "TKIP Only Prohibited"; 658 case WPS_EI_SECURITY_WEP_PROHIBITED: 659 return "WEP Prohibited"; 660 case WPS_EI_AUTH_FAILURE: 661 return "Authentication Failure"; 662 default: 663 return "Unknown"; 664 } 665 } 666