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 = data->wps->oob_dev_pw_id == 0 ?
  49                         cfg->dev_pw_id : data->wps->oob_dev_pw_id;
  50                 data->dev_password = os_malloc(cfg->pin_len);
  51                 if (data->dev_password == NULL) {
  52                         os_free(data);
  53                         return NULL;
  54                 }
  55                 os_memcpy(data->dev_password, cfg->pin, cfg->pin_len);
  56                 data->dev_password_len = cfg->pin_len;
  57         }
  58
  59 #ifdef CONFIG_WPS_NFC
  60         if (cfg->wps->ap && !cfg->registrar && cfg->wps->ap_nfc_dev_pw_id) {
  61                 data->dev_pw_id = cfg->wps->ap_nfc_dev_pw_id;
  62                 os_free(data->dev_password);
  63                 data->dev_password =
  64                         os_malloc(wpabuf_len(cfg->wps->ap_nfc_dev_pw));
  65                 if (data->dev_password == NULL) {
  66                         os_free(data);
  67                         return NULL;
  68                 }
  69                 os_memcpy(data->dev_password,
  70                           wpabuf_head(cfg->wps->ap_nfc_dev_pw),
  71                           wpabuf_len(cfg->wps->ap_nfc_dev_pw));
  72                 data->dev_password_len = wpabuf_len(cfg->wps->ap_nfc_dev_pw);
  73         }
  74 #endif /* CONFIG_WPS_NFC */
  75
  76         data->pbc = cfg->pbc;
  77         if (cfg->pbc) {
  78                 /* Use special PIN '00000000' for PBC */
  79                 data->dev_pw_id = DEV_PW_PUSHBUTTON;
  80                 os_free(data->dev_password);
  81                 data->dev_password = (u8 *) os_strdup("00000000");
  82                 if (data->dev_password == NULL) {
  83                         os_free(data);
  84                         return NULL;
  85                 }
  86                 data->dev_password_len = 8;
  87         }
  88
  89         data->state = data->registrar ? RECV_M1 : SEND_M1;
  90
  91         if (cfg->assoc_wps_ie) {
  92                 struct wps_parse_attr attr;
  93                 wpa_hexdump_buf(MSG_DEBUG, "WPS: WPS IE from (Re)AssocReq",
  94                                 cfg->assoc_wps_ie);
  95                 if (wps_parse_msg(cfg->assoc_wps_ie, &attr) < 0) {
  96                         wpa_printf(MSG_DEBUG, "WPS: Failed to parse WPS IE "
  97                                    "from (Re)AssocReq");
  98                 } else if (attr.request_type == NULL) {
  99                         wpa_printf(MSG_DEBUG, "WPS: No Request Type attribute "
 100                                    "in (Re)AssocReq WPS IE");
 101                 } else {
 102                         wpa_printf(MSG_DEBUG, "WPS: Request Type (from WPS IE "
 103                                    "in (Re)AssocReq WPS IE): %d",
 104                                    *attr.request_type);
 105                         data->request_type = *attr.request_type;
 106                 }
 107         }
 108
 109         if (cfg->new_ap_settings) {
 110                 data->new_ap_settings =
 111                         os_malloc(sizeof(*data->new_ap_settings));
 112                 if (data->new_ap_settings == NULL) {
 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: 1 if address is authorized, 0 if not
 291  */
 292 int wps_is_addr_authorized(const struct wpabuf *msg, const u8 *addr,
 293                            int ver1_compat)
 294 {
 295         struct wps_parse_attr attr;
 296         unsigned int i;
 297         const u8 *pos;
 298         const u8 bcast[ETH_ALEN] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
 299
 300         if (wps_parse_msg(msg, &attr) < 0)
 301                 return 0;
 302
 303         if (!attr.version2 && ver1_compat) {
 304                 /*
 305                  * Version 1.0 AP - AuthorizedMACs not used, so revert back to
 306                  * old mechanism of using SelectedRegistrar.
 307                  */
 308                 return is_selected_pin_registrar(&attr);
 309         }
 310
 311         if (!attr.authorized_macs)
 312                 return 0;
 313
 314         pos = attr.authorized_macs;
 315         for (i = 0; i < attr.authorized_macs_len / ETH_ALEN; i++) {
 316                 if (os_memcmp(pos, addr, ETH_ALEN) == 0 ||
 317                     os_memcmp(pos, bcast, ETH_ALEN) == 0)
 318                         return 1;
 319                 pos += ETH_ALEN;
 320         }
 321
 322         return 0;
 323 }
 324
 325
 326 /**
 327  * wps_ap_priority_compar - Prioritize WPS IE from two APs
 328  * @wps_a: WPS IE contents from Beacon or Probe Response frame
 329  * @wps_b: WPS IE contents from Beacon or Probe Response frame
 330  * Returns: 1 if wps_b is considered more likely selection for WPS
 331  * provisioning, -1 if wps_a is considered more like, or 0 if no preference
 332  */
 333 int wps_ap_priority_compar(const struct wpabuf *wps_a,
 334                            const struct wpabuf *wps_b)
 335 {
 336         struct wps_parse_attr attr_a, attr_b;
 337         int sel_a, sel_b;
 338
 339         if (wps_a == NULL || wps_parse_msg(wps_a, &attr_a) < 0)
 340                 return 1;
 341         if (wps_b == NULL || wps_parse_msg(wps_b, &attr_b) < 0)
 342                 return -1;
 343
 344         sel_a = attr_a.selected_registrar && *attr_a.selected_registrar != 0;
 345         sel_b = attr_b.selected_registrar && *attr_b.selected_registrar != 0;
 346
 347         if (sel_a && !sel_b)
 348                 return -1;
 349         if (!sel_a && sel_b)
 350                 return 1;
 351
 352         return 0;
 353 }
 354
 355
 356 /**
 357  * wps_get_uuid_e - Get UUID-E from WPS IE
 358  * @msg: WPS IE contents from Beacon or Probe Response frame
 359  * Returns: Pointer to UUID-E or %NULL if not included
 360  *
 361  * The returned pointer is to the msg contents and it remains valid only as
 362  * long as the msg buffer is valid.
 363  */
 364 const u8 * wps_get_uuid_e(const struct wpabuf *msg)
 365 {
 366         struct wps_parse_attr attr;
 367
 368         if (wps_parse_msg(msg, &attr) < 0)
 369                 return NULL;
 370         return attr.uuid_e;
 371 }
 372
 373
 374 /**
 375  * wps_is_20 - Check whether WPS attributes claim support for WPS 2.0
 376  */
 377 int wps_is_20(const struct wpabuf *msg)
 378 {
 379         struct wps_parse_attr attr;
 380
 381         if (msg == NULL || wps_parse_msg(msg, &attr) < 0)
 382                 return 0;
 383         return attr.version2 != NULL;
 384 }
 385
 386
 387 /**
 388  * wps_build_assoc_req_ie - Build WPS IE for (Re)Association Request
 389  * @req_type: Value for Request Type attribute
 390  * Returns: WPS IE or %NULL on failure
 391  *
 392  * The caller is responsible for freeing the buffer.
 393  */
 394 struct wpabuf * wps_build_assoc_req_ie(enum wps_request_type req_type)
 395 {
 396         struct wpabuf *ie;
 397         u8 *len;
 398
 399         wpa_printf(MSG_DEBUG, "WPS: Building WPS IE for (Re)Association "
 400                    "Request");
 401         ie = wpabuf_alloc(100);
 402         if (ie == NULL)
 403                 return NULL;
 404
 405         wpabuf_put_u8(ie, WLAN_EID_VENDOR_SPECIFIC);
 406         len = wpabuf_put(ie, 1);
 407         wpabuf_put_be32(ie, WPS_DEV_OUI_WFA);
 408
 409         if (wps_build_version(ie) ||
 410             wps_build_req_type(ie, req_type) ||
 411             wps_build_wfa_ext(ie, 0, NULL, 0)) {
 412                 wpabuf_free(ie);
 413                 return NULL;
 414         }
 415
 416         *len = wpabuf_len(ie) - 2;
 417
 418         return ie;
 419 }
 420
 421
 422 /**
 423  * wps_build_assoc_resp_ie - Build WPS IE for (Re)Association Response
 424  * Returns: WPS IE or %NULL on failure
 425  *
 426  * The caller is responsible for freeing the buffer.
 427  */
 428 struct wpabuf * wps_build_assoc_resp_ie(void)
 429 {
 430         struct wpabuf *ie;
 431         u8 *len;
 432
 433         wpa_printf(MSG_DEBUG, "WPS: Building WPS IE for (Re)Association "
 434                    "Response");
 435         ie = wpabuf_alloc(100);
 436         if (ie == NULL)
 437                 return NULL;
 438
 439         wpabuf_put_u8(ie, WLAN_EID_VENDOR_SPECIFIC);
 440         len = wpabuf_put(ie, 1);
 441         wpabuf_put_be32(ie, WPS_DEV_OUI_WFA);
 442
 443         if (wps_build_version(ie) ||
 444             wps_build_resp_type(ie, WPS_RESP_AP) ||
 445             wps_build_wfa_ext(ie, 0, NULL, 0)) {
 446                 wpabuf_free(ie);
 447                 return NULL;
 448         }
 449
 450         *len = wpabuf_len(ie) - 2;
 451
 452         return ie;
 453 }
 454
 455
 456 /**
 457  * wps_build_probe_req_ie - Build WPS IE for Probe Request
 458  * @pw_id: Password ID (DEV_PW_PUSHBUTTON for active PBC and DEV_PW_DEFAULT for
 459  * most other use cases)
 460  * @dev: Device attributes
 461  * @uuid: Own UUID
 462  * @req_type: Value for Request Type attribute
 463  * @num_req_dev_types: Number of requested device types
 464  * @req_dev_types: Requested device types (8 * num_req_dev_types octets) or
 465  *      %NULL if none
 466  * Returns: WPS IE or %NULL on failure
 467  *
 468  * The caller is responsible for freeing the buffer.
 469  */
 470 struct wpabuf * wps_build_probe_req_ie(u16 pw_id, struct wps_device_data *dev,
 471                                        const u8 *uuid,
 472                                        enum wps_request_type req_type,
 473                                        unsigned int num_req_dev_types,
 474                                        const u8 *req_dev_types)
 475 {
 476         struct wpabuf *ie;
 477
 478         wpa_printf(MSG_DEBUG, "WPS: Building WPS IE for Probe Request");
 479
 480         ie = wpabuf_alloc(500);
 481         if (ie == NULL)
 482                 return NULL;
 483
 484         if (wps_build_version(ie) ||
 485             wps_build_req_type(ie, req_type) ||
 486             wps_build_config_methods(ie, dev->config_methods) ||
 487             wps_build_uuid_e(ie, uuid) ||
 488             wps_build_primary_dev_type(dev, ie) ||
 489             wps_build_rf_bands(dev, ie) ||
 490             wps_build_assoc_state(NULL, ie) ||
 491             wps_build_config_error(ie, WPS_CFG_NO_ERROR) ||
 492             wps_build_dev_password_id(ie, pw_id) ||
 493 #ifdef CONFIG_WPS2
 494             wps_build_manufacturer(dev, ie) ||
 495             wps_build_model_name(dev, ie) ||
 496             wps_build_model_number(dev, ie) ||
 497             wps_build_dev_name(dev, ie) ||
 498             wps_build_wfa_ext(ie, req_type == WPS_REQ_ENROLLEE, NULL, 0) ||
 499 #endif /* CONFIG_WPS2 */
 500             wps_build_req_dev_type(dev, ie, num_req_dev_types, req_dev_types)
 501             ||
 502             wps_build_secondary_dev_type(dev, ie)
 503                 ) {
 504                 wpabuf_free(ie);
 505                 return NULL;
 506         }
 507
 508 #ifndef CONFIG_WPS2
 509         if (dev->p2p && wps_build_dev_name(dev, ie)) {
 510                 wpabuf_free(ie);
 511                 return NULL;
 512         }
 513 #endif /* CONFIG_WPS2 */
 514
 515         return wps_ie_encapsulate(ie);
 516 }
 517
 518
 519 void wps_free_pending_msgs(struct upnp_pending_message *msgs)
 520 {
 521         struct upnp_pending_message *p, *prev;
 522         p = msgs;
 523         while (p) {
 524                 prev = p;
 525                 p = p->next;
 526                 wpabuf_free(prev->msg);
 527                 os_free(prev);
 528         }
 529 }
 530
 531
 532 int wps_attr_text(struct wpabuf *data, char *buf, char *end)
 533 {
 534         struct wps_parse_attr attr;
 535         char *pos = buf;
 536         int ret;
 537
 538         if (wps_parse_msg(data, &attr) < 0)
 539                 return -1;
 540
 541         if (attr.wps_state) {
 542                 if (*attr.wps_state == WPS_STATE_NOT_CONFIGURED)
 543                         ret = os_snprintf(pos, end - pos,
 544                                           "wps_state=unconfigured\n");
 545                 else if (*attr.wps_state == WPS_STATE_CONFIGURED)
 546                         ret = os_snprintf(pos, end - pos,
 547                                           "wps_state=configured\n");
 548                 else
 549                         ret = 0;
 550                 if (ret < 0 || ret >= end - pos)
 551                         return pos - buf;
 552                 pos += ret;
 553         }
 554
 555         if (attr.ap_setup_locked && *attr.ap_setup_locked) {
 556                 ret = os_snprintf(pos, end - pos,
 557                                   "wps_ap_setup_locked=1\n");
 558                 if (ret < 0 || ret >= end - pos)
 559                         return pos - buf;
 560                 pos += ret;
 561         }
 562
 563         if (attr.selected_registrar && *attr.selected_registrar) {
 564                 ret = os_snprintf(pos, end - pos,
 565                                   "wps_selected_registrar=1\n");
 566                 if (ret < 0 || ret >= end - pos)
 567                         return pos - buf;
 568                 pos += ret;
 569         }
 570
 571         if (attr.dev_password_id) {
 572                 ret = os_snprintf(pos, end - pos,
 573                                   "wps_device_password_id=%u\n",
 574                                   WPA_GET_BE16(attr.dev_password_id));
 575                 if (ret < 0 || ret >= end - pos)
 576                         return pos - buf;
 577                 pos += ret;
 578         }
 579
 580         if (attr.sel_reg_config_methods) {
 581                 ret = os_snprintf(pos, end - pos,
 582                                   "wps_selected_registrar_config_methods="
 583                                   "0x%04x\n",
 584                                   WPA_GET_BE16(attr.sel_reg_config_methods));
 585                 if (ret < 0 || ret >= end - pos)
 586                         return pos - buf;
 587                 pos += ret;
 588         }
 589
 590         if (attr.primary_dev_type) {
 591                 char devtype[WPS_DEV_TYPE_BUFSIZE];
 592                 ret = os_snprintf(pos, end - pos,
 593                                   "wps_primary_device_type=%s\n",
 594                                   wps_dev_type_bin2str(attr.primary_dev_type,
 595                                                        devtype,
 596                                                        sizeof(devtype)));
 597                 if (ret < 0 || ret >= end - pos)
 598                         return pos - buf;
 599                 pos += ret;
 600         }
 601
 602         if (attr.dev_name) {
 603                 char *str = os_malloc(attr.dev_name_len + 1);
 604                 size_t i;
 605                 if (str == NULL)
 606                         return pos - buf;
 607                 for (i = 0; i < attr.dev_name_len; i++) {
 608                         if (attr.dev_name[i] < 32)
 609                                 str[i] = '_';
 610                         else
 611                                 str[i] = attr.dev_name[i];
 612                 }
 613                 str[i] = '\0';
 614                 ret = os_snprintf(pos, end - pos, "wps_device_name=%s\n", str);
 615                 os_free(str);
 616                 if (ret < 0 || ret >= end - pos)
 617                         return pos - buf;
 618                 pos += ret;
 619         }
 620
 621         if (attr.config_methods) {
 622                 ret = os_snprintf(pos, end - pos,
 623                                   "wps_config_methods=0x%04x\n",
 624                                   WPA_GET_BE16(attr.config_methods));
 625                 if (ret < 0 || ret >= end - pos)
 626                         return pos - buf;
 627                 pos += ret;
 628         }
 629
 630         return pos - buf;
 631 }