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