src/wps/wps.c

   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 #endif /* CONFIG_WPS_TESTING */
  22
  23
  24 /**
  25  * wps_init - Initialize WPS Registration protocol data
  26  * @cfg: WPS configuration
  27  * Returns: Pointer to allocated data or %NULL on failure
  28  *
  29  * This function is used to initialize WPS data for a registration protocol
  30  * instance (i.e., each run of registration protocol as a Registrar of
  31  * Enrollee. The caller is responsible for freeing this data after the
  32  * registration run has been completed by calling wps_deinit().
  33  */
  34 struct wps_data * wps_init(const struct wps_config *cfg)
  35 {
  36         struct wps_data *data = os_zalloc(sizeof(*data));
  37         if (data == NULL)
  38                 return NULL;
  39         data->wps = cfg->wps;
  40         data->registrar = cfg->registrar;
  41         if (cfg->registrar) {
  42                 os_memcpy(data->uuid_r, cfg->wps->uuid, WPS_UUID_LEN);
  43         } else {
  44                 os_memcpy(data->mac_addr_e, cfg->wps->dev.mac_addr, ETH_ALEN);
  45                 os_memcpy(data->uuid_e, cfg->wps->uuid, WPS_UUID_LEN);
  46         }
  47         if (cfg->pin) {
  48                 data->dev_pw_id = cfg->dev_pw_id;
  49                 data->dev_password = os_malloc(cfg->pin_len);
  50                 if (data->dev_password == NULL) {
  51                         os_free(data);
  52                         return NULL;
  53                 }
  54                 os_memcpy(data->dev_password, cfg->pin, cfg->pin_len);
  55                 data->dev_password_len = cfg->pin_len;
  56         }
  57
  58 #ifdef CONFIG_WPS_NFC
  59         if (cfg->wps->ap && !cfg->registrar && cfg->wps->ap_nfc_dev_pw_id) {
  60                 data->dev_pw_id = cfg->wps->ap_nfc_dev_pw_id;
  61                 os_free(data->dev_password);
  62                 data->dev_password =
  63                         os_malloc(wpabuf_len(cfg->wps->ap_nfc_dev_pw));
  64                 if (data->dev_password == NULL) {
  65                         os_free(data);
  66                         return NULL;
  67                 }
  68                 os_memcpy(data->dev_password,
  69                           wpabuf_head(cfg->wps->ap_nfc_dev_pw),
  70                           wpabuf_len(cfg->wps->ap_nfc_dev_pw));
  71                 data->dev_password_len = wpabuf_len(cfg->wps->ap_nfc_dev_pw);
  72         }
  73 #endif /* CONFIG_WPS_NFC */
  74
  75         data->pbc = cfg->pbc;
  76         if (cfg->pbc) {
  77                 /* Use special PIN '00000000' for PBC */
  78                 data->dev_pw_id = DEV_PW_PUSHBUTTON;
  79                 os_free(data->dev_password);
  80                 data->dev_password = (u8 *) os_strdup("00000000");
  81                 if (data->dev_password == NULL) {
  82                         os_free(data);
  83                         return NULL;
  84                 }
  85                 data->dev_password_len = 8;
  86         }
  87
  88         data->state = data->registrar ? RECV_M1 : SEND_M1;
  89
  90         if (cfg->assoc_wps_ie) {
  91                 struct wps_parse_attr attr;
  92                 wpa_hexdump_buf(MSG_DEBUG, "WPS: WPS IE from (Re)AssocReq",
  93                                 cfg->assoc_wps_ie);
  94                 if (wps_parse_msg(cfg->assoc_wps_ie, &attr) < 0) {
  95                         wpa_printf(MSG_DEBUG, "WPS: Failed to parse WPS IE "
  96                                    "from (Re)AssocReq");
  97                 } else if (attr.request_type == NULL) {
  98                         wpa_printf(MSG_DEBUG, "WPS: No Request Type attribute "
  99                                    "in (Re)AssocReq WPS IE");
 100                 } else {
 101                         wpa_printf(MSG_DEBUG, "WPS: Request Type (from WPS IE "
 102                                    "in (Re)AssocReq WPS IE): %d",
 103                                    *attr.request_type);
 104                         data->request_type = *attr.request_type;
 105                 }
 106         }
 107
 108         if (cfg->new_ap_settings) {
 109                 data->new_ap_settings =
 110                         os_malloc(sizeof(*data->new_ap_settings));
 111                 if (data->new_ap_settings == NULL) {
 112                         os_free(data->dev_password);
 113                         os_free(data);
 114                         return NULL;
 115                 }
 116                 os_memcpy(data->new_ap_settings, cfg->new_ap_settings,
 117                           sizeof(*data->new_ap_settings));
 118         }
 119
 120         if (cfg->peer_addr)
 121                 os_memcpy(data->peer_dev.mac_addr, cfg->peer_addr, ETH_ALEN);
 122         if (cfg->p2p_dev_addr)
 123                 os_memcpy(data->p2p_dev_addr, cfg->p2p_dev_addr, ETH_ALEN);
 124
 125         data->use_psk_key = cfg->use_psk_key;
 126         data->pbc_in_m1 = cfg->pbc_in_m1;
 127
 128         return data;
 129 }
 130
 131
 132 /**
 133  * wps_deinit - Deinitialize WPS Registration protocol data
 134  * @data: WPS Registration protocol data from wps_init()
 135  */
 136 void wps_deinit(struct wps_data *data)
 137 {
 138 #ifdef CONFIG_WPS_NFC
 139         if (data->registrar && data->nfc_pw_token)
 140                 wps_registrar_remove_nfc_pw_token(data->wps->registrar,
 141                                                   data->nfc_pw_token);
 142 #endif /* CONFIG_WPS_NFC */
 143
 144         if (data->wps_pin_revealed) {
 145                 wpa_printf(MSG_DEBUG, "WPS: Full PIN information revealed and "
 146                            "negotiation failed");
 147                 if (data->registrar)
 148                         wps_registrar_invalidate_pin(data->wps->registrar,
 149                                                      data->uuid_e);
 150         } else if (data->registrar)
 151                 wps_registrar_unlock_pin(data->wps->registrar, data->uuid_e);
 152
 153         wpabuf_free(data->dh_privkey);
 154         wpabuf_free(data->dh_pubkey_e);
 155         wpabuf_free(data->dh_pubkey_r);
 156         wpabuf_free(data->last_msg);
 157         os_free(data->dev_password);
 158         os_free(data->new_psk);
 159         wps_device_data_free(&data->peer_dev);
 160         os_free(data->new_ap_settings);
 161         dh5_free(data->dh_ctx);
 162         os_free(data->nfc_pw_token);
 163         os_free(data);
 164 }
 165
 166
 167 /**
 168  * wps_process_msg - Process a WPS message
 169  * @wps: WPS Registration protocol data from wps_init()
 170  * @op_code: Message OP Code
 171  * @msg: Message data
 172  * Returns: Processing result
 173  *
 174  * This function is used to process WPS messages with OP Codes WSC_ACK,
 175  * WSC_NACK, WSC_MSG, and WSC_Done. The caller (e.g., EAP server/peer) is
 176  * responsible for reassembling the messages before calling this function.
 177  * Response to this message is built by calling wps_get_msg().
 178  */
 179 enum wps_process_res wps_process_msg(struct wps_data *wps,
 180                                      enum wsc_op_code op_code,
 181                                      const struct wpabuf *msg)
 182 {
 183         if (wps->registrar)
 184                 return wps_registrar_process_msg(wps, op_code, msg);
 185         else
 186                 return wps_enrollee_process_msg(wps, op_code, msg);
 187 }
 188
 189
 190 /**
 191  * wps_get_msg - Build a WPS message
 192  * @wps: WPS Registration protocol data from wps_init()
 193  * @op_code: Buffer for returning message OP Code
 194  * Returns: The generated WPS message or %NULL on failure
 195  *
 196  * This function is used to build a response to a message processed by calling
 197  * wps_process_msg(). The caller is responsible for freeing the buffer.
 198  */
 199 struct wpabuf * wps_get_msg(struct wps_data *wps, enum wsc_op_code *op_code)
 200 {
 201         if (wps->registrar)
 202                 return wps_registrar_get_msg(wps, op_code);
 203         else
 204                 return wps_enrollee_get_msg(wps, op_code);
 205 }
 206
 207
 208 /**
 209  * wps_is_selected_pbc_registrar - Check whether WPS IE indicates active PBC
 210  * @msg: WPS IE contents from Beacon or Probe Response frame
 211  * Returns: 1 if PBC Registrar is active, 0 if not
 212  */
 213 int wps_is_selected_pbc_registrar(const struct wpabuf *msg)
 214 {
 215         struct wps_parse_attr attr;
 216
 217         /*
 218          * In theory, this could also verify that attr.sel_reg_config_methods
 219          * includes WPS_CONFIG_PUSHBUTTON, but some deployed AP implementations
 220          * do not set Selected Registrar Config Methods attribute properly, so
 221          * it is safer to just use Device Password ID here.
 222          */
 223
 224         if (wps_parse_msg(msg, &attr) < 0 ||
 225             !attr.selected_registrar || *attr.selected_registrar == 0 ||
 226             !attr.dev_password_id ||
 227             WPA_GET_BE16(attr.dev_password_id) != DEV_PW_PUSHBUTTON)
 228                 return 0;
 229
 230 #ifdef CONFIG_WPS_STRICT
 231         if (!attr.sel_reg_config_methods ||
 232             !(WPA_GET_BE16(attr.sel_reg_config_methods) &
 233               WPS_CONFIG_PUSHBUTTON))
 234                 return 0;
 235 #endif /* CONFIG_WPS_STRICT */
 236
 237         return 1;
 238 }
 239
 240
 241 static int is_selected_pin_registrar(struct wps_parse_attr *attr)
 242 {
 243         /*
 244          * In theory, this could also verify that attr.sel_reg_config_methods
 245          * includes WPS_CONFIG_LABEL, WPS_CONFIG_DISPLAY, or WPS_CONFIG_KEYPAD,
 246          * but some deployed AP implementations do not set Selected Registrar
 247          * Config Methods attribute properly, so it is safer to just use
 248          * Device Password ID here.
 249          */
 250
 251         if (!attr->selected_registrar || *attr->selected_registrar == 0)
 252                 return 0;
 253
 254         if (attr->dev_password_id != NULL &&
 255             WPA_GET_BE16(attr->dev_password_id) == DEV_PW_PUSHBUTTON)
 256                 return 0;
 257
 258 #ifdef CONFIG_WPS_STRICT
 259         if (!attr->sel_reg_config_methods ||
 260             !(WPA_GET_BE16(attr->sel_reg_config_methods) &
 261               (WPS_CONFIG_LABEL | WPS_CONFIG_DISPLAY | WPS_CONFIG_KEYPAD)))
 262                 return 0;
 263 #endif /* CONFIG_WPS_STRICT */
 264
 265         return 1;
 266 }
 267
 268
 269 /**
 270  * wps_is_selected_pin_registrar - Check whether WPS IE indicates active PIN
 271  * @msg: WPS IE contents from Beacon or Probe Response frame
 272  * Returns: 1 if PIN Registrar is active, 0 if not
 273  */
 274 int wps_is_selected_pin_registrar(const struct wpabuf *msg)
 275 {
 276         struct wps_parse_attr attr;
 277
 278         if (wps_parse_msg(msg, &attr) < 0)
 279                 return 0;
 280
 281         return is_selected_pin_registrar(&attr);
 282 }
 283
 284
 285 /**
 286  * wps_is_addr_authorized - Check whether WPS IE authorizes MAC address
 287  * @msg: WPS IE contents from Beacon or Probe Response frame
 288  * @addr: MAC address to search for
 289  * @ver1_compat: Whether to use version 1 compatibility mode
 290  * Returns: 2 if the specified address is explicit authorized, 1 if address is
 291  * authorized (broadcast), 0 if not
 292  */
 293 int wps_is_addr_authorized(const struct wpabuf *msg, const u8 *addr,
 294                            int ver1_compat)
 295 {
 296         struct wps_parse_attr attr;
 297         unsigned int i;
 298         const u8 *pos;
 299         const u8 bcast[ETH_ALEN] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
 300
 301         if (wps_parse_msg(msg, &attr) < 0)
 302                 return 0;
 303
 304         if (!attr.version2 && ver1_compat) {
 305                 /*
 306                  * Version 1.0 AP - AuthorizedMACs not used, so revert back to
 307                  * old mechanism of using SelectedRegistrar.
 308                  */
 309                 return is_selected_pin_registrar(&attr);
 310         }
 311
 312         if (!attr.authorized_macs)
 313                 return 0;
 314
 315         pos = attr.authorized_macs;
 316         for (i = 0; i < attr.authorized_macs_len / ETH_ALEN; i++) {
 317                 if (os_memcmp(pos, addr, ETH_ALEN) == 0)
 318                         return 2;
 319                 if (os_memcmp(pos, bcast, ETH_ALEN) == 0)
 320                         return 1;
 321                 pos += ETH_ALEN;
 322         }
 323
 324         return 0;
 325 }
 326
 327
 328 /**
 329  * wps_ap_priority_compar - Prioritize WPS IE from two APs
 330  * @wps_a: WPS IE contents from Beacon or Probe Response frame
 331  * @wps_b: WPS IE contents from Beacon or Probe Response frame
 332  * Returns: 1 if wps_b is considered more likely selection for WPS
 333  * provisioning, -1 if wps_a is considered more like, or 0 if no preference
 334  */
 335 int wps_ap_priority_compar(const struct wpabuf *wps_a,
 336                            const struct wpabuf *wps_b)
 337 {
 338         struct wps_parse_attr attr_a, attr_b;
 339         int sel_a, sel_b;
 340
 341         if (wps_a == NULL || wps_parse_msg(wps_a, &attr_a) < 0)
 342                 return 1;
 343         if (wps_b == NULL || wps_parse_msg(wps_b, &attr_b) < 0)
 344                 return -1;
 345
 346         sel_a = attr_a.selected_registrar && *attr_a.selected_registrar != 0;
 347         sel_b = attr_b.selected_registrar && *attr_b.selected_registrar != 0;
 348
 349         if (sel_a && !sel_b)
 350                 return -1;
 351         if (!sel_a && sel_b)
 352                 return 1;
 353
 354         return 0;
 355 }
 356
 357
 358 /**
 359  * wps_get_uuid_e - Get UUID-E from WPS IE
 360  * @msg: WPS IE contents from Beacon or Probe Response frame
 361  * Returns: Pointer to UUID-E or %NULL if not included
 362  *
 363  * The returned pointer is to the msg contents and it remains valid only as
 364  * long as the msg buffer is valid.
 365  */
 366 const u8 * wps_get_uuid_e(const struct wpabuf *msg)
 367 {
 368         struct wps_parse_attr attr;
 369
 370         if (wps_parse_msg(msg, &attr) < 0)
 371                 return NULL;
 372         return attr.uuid_e;
 373 }
 374
 375
 376 /**
 377  * wps_is_20 - Check whether WPS attributes claim support for WPS 2.0
 378  */
 379 int wps_is_20(const struct wpabuf *msg)
 380 {
 381         struct wps_parse_attr attr;
 382
 383         if (msg == NULL || wps_parse_msg(msg, &attr) < 0)
 384                 return 0;
 385         return attr.version2 != NULL;
 386 }
 387
 388
 389 /**
 390  * wps_build_assoc_req_ie - Build WPS IE for (Re)Association Request
 391  * @req_type: Value for Request Type attribute
 392  * Returns: WPS IE or %NULL on failure
 393  *
 394  * The caller is responsible for freeing the buffer.
 395  */
 396 struct wpabuf * wps_build_assoc_req_ie(enum wps_request_type req_type)
 397 {
 398         struct wpabuf *ie;
 399         u8 *len;
 400
 401         wpa_printf(MSG_DEBUG, "WPS: Building WPS IE for (Re)Association "
 402                    "Request");
 403         ie = wpabuf_alloc(100);
 404         if (ie == NULL)
 405                 return NULL;
 406
 407         wpabuf_put_u8(ie, WLAN_EID_VENDOR_SPECIFIC);
 408         len = wpabuf_put(ie, 1);
 409         wpabuf_put_be32(ie, WPS_DEV_OUI_WFA);
 410
 411         if (wps_build_version(ie) ||
 412             wps_build_req_type(ie, req_type) ||
 413             wps_build_wfa_ext(ie, 0, NULL, 0)) {
 414                 wpabuf_free(ie);
 415                 return NULL;
 416         }
 417
 418         *len = wpabuf_len(ie) - 2;
 419
 420         return ie;
 421 }
 422
 423
 424 /**
 425  * wps_build_assoc_resp_ie - Build WPS IE for (Re)Association Response
 426  * Returns: WPS IE or %NULL on failure
 427  *
 428  * The caller is responsible for freeing the buffer.
 429  */
 430 struct wpabuf * wps_build_assoc_resp_ie(void)
 431 {
 432         struct wpabuf *ie;
 433         u8 *len;
 434
 435         wpa_printf(MSG_DEBUG, "WPS: Building WPS IE for (Re)Association "
 436                    "Response");
 437         ie = wpabuf_alloc(100);
 438         if (ie == NULL)
 439                 return NULL;
 440
 441         wpabuf_put_u8(ie, WLAN_EID_VENDOR_SPECIFIC);
 442         len = wpabuf_put(ie, 1);
 443         wpabuf_put_be32(ie, WPS_DEV_OUI_WFA);
 444
 445         if (wps_build_version(ie) ||
 446             wps_build_resp_type(ie, WPS_RESP_AP) ||
 447             wps_build_wfa_ext(ie, 0, NULL, 0)) {
 448                 wpabuf_free(ie);
 449                 return NULL;
 450         }
 451
 452         *len = wpabuf_len(ie) - 2;
 453
 454         return ie;
 455 }
 456
 457
 458 /**
 459  * wps_build_probe_req_ie - Build WPS IE for Probe Request
 460  * @pw_id: Password ID (DEV_PW_PUSHBUTTON for active PBC and DEV_PW_DEFAULT for
 461  * most other use cases)
 462  * @dev: Device attributes
 463  * @uuid: Own UUID
 464  * @req_type: Value for Request Type attribute
 465  * @num_req_dev_types: Number of requested device types
 466  * @req_dev_types: Requested device types (8 * num_req_dev_types octets) or
 467  *      %NULL if none
 468  * Returns: WPS IE or %NULL on failure
 469  *
 470  * The caller is responsible for freeing the buffer.
 471  */
 472 struct wpabuf * wps_build_probe_req_ie(u16 pw_id, struct wps_device_data *dev,
 473                                        const u8 *uuid,
 474                                        enum wps_request_type req_type,
 475                                        unsigned int num_req_dev_types,
 476                                        const u8 *req_dev_types)
 477 {
 478         struct wpabuf *ie;
 479
 480         wpa_printf(MSG_DEBUG, "WPS: Building WPS IE for Probe Request");
 481
 482         ie = wpabuf_alloc(500);
 483         if (ie == NULL)
 484                 return NULL;
 485
 486         if (wps_build_version(ie) ||
 487             wps_build_req_type(ie, req_type) ||
 488             wps_build_config_methods(ie, dev->config_methods) ||
 489             wps_build_uuid_e(ie, uuid) ||
 490             wps_build_primary_dev_type(dev, ie) ||
 491             wps_build_rf_bands(dev, ie) ||
 492             wps_build_assoc_state(NULL, ie) ||
 493             wps_build_config_error(ie, WPS_CFG_NO_ERROR) ||
 494             wps_build_dev_password_id(ie, pw_id) ||
 495 #ifdef CONFIG_WPS2
 496             wps_build_manufacturer(dev, ie) ||
 497             wps_build_model_name(dev, ie) ||
 498             wps_build_model_number(dev, ie) ||
 499             wps_build_dev_name(dev, ie) ||
 500             wps_build_wfa_ext(ie, req_type == WPS_REQ_ENROLLEE, NULL, 0) ||
 501 #endif /* CONFIG_WPS2 */
 502             wps_build_req_dev_type(dev, ie, num_req_dev_types, req_dev_types)
 503             ||
 504             wps_build_secondary_dev_type(dev, ie)
 505                 ) {
 506                 wpabuf_free(ie);
 507                 return NULL;
 508         }
 509
 510 #ifndef CONFIG_WPS2
 511         if (dev->p2p && wps_build_dev_name(dev, ie)) {
 512                 wpabuf_free(ie);
 513                 return NULL;
 514         }
 515 #endif /* CONFIG_WPS2 */
 516
 517         return wps_ie_encapsulate(ie);
 518 }
 519
 520
 521 void wps_free_pending_msgs(struct upnp_pending_message *msgs)
 522 {
 523         struct upnp_pending_message *p, *prev;
 524         p = msgs;
 525         while (p) {
 526                 prev = p;
 527                 p = p->next;
 528                 wpabuf_free(prev->msg);
 529                 os_free(prev);
 530         }
 531 }
 532
 533
 534 int wps_attr_text(struct wpabuf *data, char *buf, char *end)
 535 {
 536         struct wps_parse_attr attr;
 537         char *pos = buf;
 538         int ret;
 539
 540         if (wps_parse_msg(data, &attr) < 0)
 541                 return -1;
 542
 543         if (attr.wps_state) {
 544                 if (*attr.wps_state == WPS_STATE_NOT_CONFIGURED)
 545                         ret = os_snprintf(pos, end - pos,
 546                                           "wps_state=unconfigured\n");
 547                 else if (*attr.wps_state == WPS_STATE_CONFIGURED)
 548                         ret = os_snprintf(pos, end - pos,
 549                                           "wps_state=configured\n");
 550                 else
 551                         ret = 0;
 552                 if (ret < 0 || ret >= end - pos)
 553                         return pos - buf;
 554                 pos += ret;
 555         }
 556
 557         if (attr.ap_setup_locked && *attr.ap_setup_locked) {
 558                 ret = os_snprintf(pos, end - pos,
 559                                   "wps_ap_setup_locked=1\n");
 560                 if (ret < 0 || ret >= end - pos)
 561                         return pos - buf;
 562                 pos += ret;
 563         }
 564
 565         if (attr.selected_registrar && *attr.selected_registrar) {
 566                 ret = os_snprintf(pos, end - pos,
 567                                   "wps_selected_registrar=1\n");
 568                 if (ret < 0 || ret >= end - pos)
 569                         return pos - buf;
 570                 pos += ret;
 571         }
 572
 573         if (attr.dev_password_id) {
 574                 ret = os_snprintf(pos, end - pos,
 575                                   "wps_device_password_id=%u\n",
 576                                   WPA_GET_BE16(attr.dev_password_id));
 577                 if (ret < 0 || ret >= end - pos)
 578                         return pos - buf;
 579                 pos += ret;
 580         }
 581
 582         if (attr.sel_reg_config_methods) {
 583                 ret = os_snprintf(pos, end - pos,
 584                                   "wps_selected_registrar_config_methods="
 585                                   "0x%04x\n",
 586                                   WPA_GET_BE16(attr.sel_reg_config_methods));
 587                 if (ret < 0 || ret >= end - pos)
 588                         return pos - buf;
 589                 pos += ret;
 590         }
 591
 592         if (attr.primary_dev_type) {
 593                 char devtype[WPS_DEV_TYPE_BUFSIZE];
 594                 ret = os_snprintf(pos, end - pos,
 595                                   "wps_primary_device_type=%s\n",
 596                                   wps_dev_type_bin2str(attr.primary_dev_type,
 597                                                        devtype,
 598                                                        sizeof(devtype)));
 599                 if (ret < 0 || ret >= end - pos)
 600                         return pos - buf;
 601                 pos += ret;
 602         }
 603
 604         if (attr.dev_name) {
 605                 char *str = os_malloc(attr.dev_name_len + 1);
 606                 size_t i;
 607                 if (str == NULL)
 608                         return pos - buf;
 609                 for (i = 0; i < attr.dev_name_len; i++) {
 610                         if (attr.dev_name[i] < 32)
 611                                 str[i] = '_';
 612                         else
 613                                 str[i] = attr.dev_name[i];
 614                 }
 615                 str[i] = '\0';
 616                 ret = os_snprintf(pos, end - pos, "wps_device_name=%s\n", str);
 617                 os_free(str);
 618                 if (ret < 0 || ret >= end - pos)
 619                         return pos - buf;
 620                 pos += ret;
 621         }
 622
 623         if (attr.config_methods) {
 624                 ret = os_snprintf(pos, end - pos,
 625                                   "wps_config_methods=0x%04x\n",
 626                                   WPA_GET_BE16(attr.config_methods));
 627                 if (ret < 0 || ret >= end - pos)
 628                         return pos - buf;
 629                 pos += ret;
 630         }
 631
 632         return pos - buf;
 633 }