libeap/src/eap_peer/eap_wsc.c

   1 /*
   2  * EAP-WSC peer for Wi-Fi Protected Setup
   3  * Copyright (c) 2007-2009, 2012, 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 "uuid.h"
  13 #include "eap_i.h"
  14 #include "eap_common/eap_wsc_common.h"
  15 #include "wps/wps.h"
  16 #include "wps/wps_defs.h"
  17
  18
  19 struct eap_wsc_data {
  20         enum { WAIT_START, MESG, FRAG_ACK, WAIT_FRAG_ACK, DONE, FAIL } state;
  21         int registrar;
  22         struct wpabuf *in_buf;
  23         struct wpabuf *out_buf;
  24         enum wsc_op_code in_op_code, out_op_code;
  25         size_t out_used;
  26         size_t fragment_size;
  27         struct wps_data *wps;
  28         struct wps_context *wps_ctx;
  29 };
  30
  31
  32 static const char * eap_wsc_state_txt(int state)
  33 {
  34         switch (state) {
  35         case WAIT_START:
  36                 return "WAIT_START";
  37         case MESG:
  38                 return "MESG";
  39         case FRAG_ACK:
  40                 return "FRAG_ACK";
  41         case WAIT_FRAG_ACK:
  42                 return "WAIT_FRAG_ACK";
  43         case DONE:
  44                 return "DONE";
  45         case FAIL:
  46                 return "FAIL";
  47         default:
  48                 return "?";
  49         }
  50 }
  51
  52
  53 static void eap_wsc_state(struct eap_wsc_data *data, int state)
  54 {
  55         wpa_printf(MSG_DEBUG, "EAP-WSC: %s -> %s",
  56                    eap_wsc_state_txt(data->state),
  57                    eap_wsc_state_txt(state));
  58         data->state = state;
  59 }
  60
  61
  62 static int eap_wsc_new_ap_settings(struct wps_credential *cred,
  63                                    const char *params)
  64 {
  65         const char *pos, *end;
  66         size_t len;
  67
  68         os_memset(cred, 0, sizeof(*cred));
  69
  70         pos = os_strstr(params, "new_ssid=");
  71         if (pos == NULL)
  72                 return 0;
  73         pos += 9;
  74         end = os_strchr(pos, ' ');
  75         if (end == NULL)
  76                 len = os_strlen(pos);
  77         else
  78                 len = end - pos;
  79         if ((len & 1) || len > 2 * sizeof(cred->ssid) ||
  80             hexstr2bin(pos, cred->ssid, len / 2)) {
  81                 wpa_printf(MSG_DEBUG, "EAP-WSC: Invalid new_ssid");
  82                 return -1;
  83         }
  84         cred->ssid_len = len / 2;
  85
  86         pos = os_strstr(params, "new_auth=");
  87         if (pos == NULL) {
  88                 wpa_printf(MSG_DEBUG, "EAP-WSC: Missing new_auth");
  89                 return -1;
  90         }
  91         if (os_strncmp(pos + 9, "OPEN", 4) == 0)
  92                 cred->auth_type = WPS_AUTH_OPEN;
  93         else if (os_strncmp(pos + 9, "WPAPSK", 6) == 0)
  94                 cred->auth_type = WPS_AUTH_WPAPSK;
  95         else if (os_strncmp(pos + 9, "WPA2PSK", 7) == 0)
  96                 cred->auth_type = WPS_AUTH_WPA2PSK;
  97         else {
  98                 wpa_printf(MSG_DEBUG, "EAP-WSC: Unknown new_auth");
  99                 return -1;
 100         }
 101
 102         pos = os_strstr(params, "new_encr=");
 103         if (pos == NULL) {
 104                 wpa_printf(MSG_DEBUG, "EAP-WSC: Missing new_encr");
 105                 return -1;
 106         }
 107         if (os_strncmp(pos + 9, "NONE", 4) == 0)
 108                 cred->encr_type = WPS_ENCR_NONE;
 109 #ifdef CONFIG_TESTING_OPTIONS
 110         else if (os_strncmp(pos + 9, "WEP", 3) == 0)
 111                 cred->encr_type = WPS_ENCR_WEP;
 112 #endif /* CONFIG_TESTING_OPTIONS */
 113         else if (os_strncmp(pos + 9, "TKIP", 4) == 0)
 114                 cred->encr_type = WPS_ENCR_TKIP;
 115         else if (os_strncmp(pos + 9, "CCMP", 4) == 0)
 116                 cred->encr_type = WPS_ENCR_AES;
 117         else {
 118                 wpa_printf(MSG_DEBUG, "EAP-WSC: Unknown new_encr");
 119                 return -1;
 120         }
 121
 122         pos = os_strstr(params, "new_key=");
 123         if (pos == NULL)
 124                 return 0;
 125         pos += 8;
 126         end = os_strchr(pos, ' ');
 127         if (end == NULL)
 128                 len = os_strlen(pos);
 129         else
 130                 len = end - pos;
 131         if ((len & 1) || len > 2 * sizeof(cred->key) ||
 132             hexstr2bin(pos, cred->key, len / 2)) {
 133                 wpa_printf(MSG_DEBUG, "EAP-WSC: Invalid new_key");
 134                 return -1;
 135         }
 136         cred->key_len = len / 2;
 137
 138         return 1;
 139 }
 140
 141
 142 static void * eap_wsc_init(struct eap_sm *sm)
 143 {
 144         struct eap_wsc_data *data;
 145         const u8 *identity;
 146         size_t identity_len;
 147         int registrar;
 148         struct wps_config cfg;
 149         const char *pos, *end;
 150         const char *phase1;
 151         struct wps_context *wps;
 152         struct wps_credential new_ap_settings;
 153         int res;
 154         int nfc = 0;
 155         u8 pkhash[WPS_OOB_PUBKEY_HASH_LEN];
 156
 157         wps = sm->wps;
 158         if (wps == NULL) {
 159                 wpa_printf(MSG_ERROR, "EAP-WSC: WPS context not available");
 160                 return NULL;
 161         }
 162
 163         identity = eap_get_config_identity(sm, &identity_len);
 164
 165         if (identity && identity_len == WSC_ID_REGISTRAR_LEN &&
 166             os_memcmp(identity, WSC_ID_REGISTRAR, WSC_ID_REGISTRAR_LEN) == 0)
 167                 registrar = 1; /* Supplicant is Registrar */
 168         else if (identity && identity_len == WSC_ID_ENROLLEE_LEN &&
 169             os_memcmp(identity, WSC_ID_ENROLLEE, WSC_ID_ENROLLEE_LEN) == 0)
 170                 registrar = 0; /* Supplicant is Enrollee */
 171         else {
 172                 wpa_hexdump_ascii(MSG_INFO, "EAP-WSC: Unexpected identity",
 173                                   identity, identity_len);
 174                 return NULL;
 175         }
 176
 177         data = os_zalloc(sizeof(*data));
 178         if (data == NULL)
 179                 return NULL;
 180         data->state = registrar ? MESG : WAIT_START;
 181         data->registrar = registrar;
 182         data->wps_ctx = wps;
 183
 184         os_memset(&cfg, 0, sizeof(cfg));
 185         cfg.wps = wps;
 186         cfg.registrar = registrar;
 187
 188         phase1 = eap_get_config_phase1(sm);
 189         if (phase1 == NULL) {
 190                 wpa_printf(MSG_INFO, "EAP-WSC: phase1 configuration data not "
 191                            "set");
 192                 os_free(data);
 193                 return NULL;
 194         }
 195
 196         pos = os_strstr(phase1, "pin=");
 197         if (pos) {
 198                 pos += 4;
 199                 cfg.pin = (const u8 *) pos;
 200                 while (*pos != '\0' && *pos != ' ')
 201                         pos++;
 202                 cfg.pin_len = pos - (const char *) cfg.pin;
 203                 if (cfg.pin_len == 6 &&
 204                     os_strncmp((const char *) cfg.pin, "nfc-pw", 6) == 0) {
 205                         cfg.pin = NULL;
 206                         cfg.pin_len = 0;
 207                         nfc = 1;
 208                 }
 209         } else {
 210                 pos = os_strstr(phase1, "pbc=1");
 211                 if (pos)
 212                         cfg.pbc = 1;
 213         }
 214
 215         pos = os_strstr(phase1, "dev_pw_id=");
 216         if (pos) {
 217                 u16 id = atoi(pos + 10);
 218                 if (id == DEV_PW_NFC_CONNECTION_HANDOVER)
 219                         nfc = 1;
 220                 if (cfg.pin || id == DEV_PW_NFC_CONNECTION_HANDOVER)
 221                         cfg.dev_pw_id = id;
 222         }
 223
 224         if (cfg.pin == NULL && !cfg.pbc && !nfc) {
 225                 wpa_printf(MSG_INFO, "EAP-WSC: PIN or PBC not set in phase1 "
 226                            "configuration data");
 227                 os_free(data);
 228                 return NULL;
 229         }
 230
 231         pos = os_strstr(phase1, " pkhash=");
 232         if (pos) {
 233                 size_t len;
 234                 pos += 8;
 235                 end = os_strchr(pos, ' ');
 236                 if (end)
 237                         len = end - pos;
 238                 else
 239                         len = os_strlen(pos);
 240                 if (len != 2 * WPS_OOB_PUBKEY_HASH_LEN ||
 241                     hexstr2bin(pos, pkhash, WPS_OOB_PUBKEY_HASH_LEN)) {
 242                         wpa_printf(MSG_INFO, "EAP-WSC: Invalid pkhash");
 243                         os_free(data);
 244                         return NULL;
 245                 }
 246                 cfg.peer_pubkey_hash = pkhash;
 247         }
 248
 249         res = eap_wsc_new_ap_settings(&new_ap_settings, phase1);
 250         if (res < 0) {
 251                 os_free(data);
 252                 wpa_printf(MSG_DEBUG, "EAP-WSC: Failed to parse new AP "
 253                            "settings");
 254                 return NULL;
 255         }
 256         if (res == 1) {
 257                 wpa_printf(MSG_DEBUG, "EAP-WSC: Provide new AP settings for "
 258                            "WPS");
 259                 cfg.new_ap_settings = &new_ap_settings;
 260         }
 261
 262         data->wps = wps_init(&cfg);
 263         if (data->wps == NULL) {
 264                 os_free(data);
 265                 wpa_printf(MSG_DEBUG, "EAP-WSC: wps_init failed");
 266                 return NULL;
 267         }
 268         res = eap_get_config_fragment_size(sm);
 269         if (res > 0)
 270                 data->fragment_size = res;
 271         else
 272                 data->fragment_size = WSC_FRAGMENT_SIZE;
 273         wpa_printf(MSG_DEBUG, "EAP-WSC: Fragment size limit %u",
 274                    (unsigned int) data->fragment_size);
 275
 276         if (registrar && cfg.pin) {
 277                 wps_registrar_add_pin(data->wps_ctx->registrar, NULL, NULL,
 278                                       cfg.pin, cfg.pin_len, 0);
 279         }
 280
 281         /* Use reduced client timeout for WPS to avoid long wait */
 282         if (sm->ClientTimeout > 30)
 283                 sm->ClientTimeout = 30;
 284
 285         return data;
 286 }
 287
 288
 289 static void eap_wsc_deinit(struct eap_sm *sm, void *priv)
 290 {
 291         struct eap_wsc_data *data = priv;
 292         wpabuf_free(data->in_buf);
 293         wpabuf_free(data->out_buf);
 294         wps_deinit(data->wps);
 295         os_free(data->wps_ctx->network_key);
 296         data->wps_ctx->network_key = NULL;
 297         os_free(data);
 298 }
 299
 300
 301 static struct wpabuf * eap_wsc_build_msg(struct eap_wsc_data *data,
 302                                          struct eap_method_ret *ret, u8 id)
 303 {
 304         struct wpabuf *resp;
 305         u8 flags;
 306         size_t send_len, plen;
 307
 308         ret->ignore = FALSE;
 309         wpa_printf(MSG_DEBUG, "EAP-WSC: Generating Response");
 310         ret->allowNotifications = TRUE;
 311
 312         flags = 0;
 313         send_len = wpabuf_len(data->out_buf) - data->out_used;
 314         if (2 + send_len > data->fragment_size) {
 315                 send_len = data->fragment_size - 2;
 316                 flags |= WSC_FLAGS_MF;
 317                 if (data->out_used == 0) {
 318                         flags |= WSC_FLAGS_LF;
 319                         send_len -= 2;
 320                 }
 321         }
 322         plen = 2 + send_len;
 323         if (flags & WSC_FLAGS_LF)
 324                 plen += 2;
 325         resp = eap_msg_alloc(EAP_VENDOR_WFA, EAP_VENDOR_TYPE_WSC, plen,
 326                              EAP_CODE_RESPONSE, id);
 327         if (resp == NULL)
 328                 return NULL;
 329
 330         wpabuf_put_u8(resp, data->out_op_code); /* Op-Code */
 331         wpabuf_put_u8(resp, flags); /* Flags */
 332         if (flags & WSC_FLAGS_LF)
 333                 wpabuf_put_be16(resp, wpabuf_len(data->out_buf));
 334
 335         wpabuf_put_data(resp, wpabuf_head_u8(data->out_buf) + data->out_used,
 336                         send_len);
 337         data->out_used += send_len;
 338
 339         ret->methodState = METHOD_MAY_CONT;
 340         ret->decision = DECISION_FAIL;
 341
 342         if (data->out_used == wpabuf_len(data->out_buf)) {
 343                 wpa_printf(MSG_DEBUG, "EAP-WSC: Sending out %lu bytes "
 344                            "(message sent completely)",
 345                            (unsigned long) send_len);
 346                 wpabuf_free(data->out_buf);
 347                 data->out_buf = NULL;
 348                 data->out_used = 0;
 349                 if ((data->state == FAIL && data->out_op_code == WSC_ACK) ||
 350                     data->out_op_code == WSC_NACK ||
 351                     data->out_op_code == WSC_Done) {
 352                         eap_wsc_state(data, FAIL);
 353                         ret->methodState = METHOD_DONE;
 354                 } else
 355                         eap_wsc_state(data, MESG);
 356         } else {
 357                 wpa_printf(MSG_DEBUG, "EAP-WSC: Sending out %lu bytes "
 358                            "(%lu more to send)", (unsigned long) send_len,
 359                            (unsigned long) wpabuf_len(data->out_buf) -
 360                            data->out_used);
 361                 eap_wsc_state(data, WAIT_FRAG_ACK);
 362         }
 363
 364         return resp;
 365 }
 366
 367
 368 static int eap_wsc_process_cont(struct eap_wsc_data *data,
 369                                 const u8 *buf, size_t len, u8 op_code)
 370 {
 371         /* Process continuation of a pending message */
 372         if (op_code != data->in_op_code) {
 373                 wpa_printf(MSG_DEBUG, "EAP-WSC: Unexpected Op-Code %d in "
 374                            "fragment (expected %d)",
 375                            op_code, data->in_op_code);
 376                 return -1;
 377         }
 378
 379         if (len > wpabuf_tailroom(data->in_buf)) {
 380                 wpa_printf(MSG_DEBUG, "EAP-WSC: Fragment overflow");
 381                 eap_wsc_state(data, FAIL);
 382                 return -1;
 383         }
 384
 385         wpabuf_put_data(data->in_buf, buf, len);
 386         wpa_printf(MSG_DEBUG, "EAP-WSC: Received %lu bytes, waiting "
 387                    "for %lu bytes more", (unsigned long) len,
 388                    (unsigned long) wpabuf_tailroom(data->in_buf));
 389
 390         return 0;
 391 }
 392
 393
 394 static struct wpabuf * eap_wsc_process_fragment(struct eap_wsc_data *data,
 395                                                 struct eap_method_ret *ret,
 396                                                 u8 id, u8 flags, u8 op_code,
 397                                                 u16 message_length,
 398                                                 const u8 *buf, size_t len)
 399 {
 400         /* Process a fragment that is not the last one of the message */
 401         if (data->in_buf == NULL && !(flags & WSC_FLAGS_LF)) {
 402                 wpa_printf(MSG_DEBUG, "EAP-WSC: No Message Length field in a "
 403                            "fragmented packet");
 404                 ret->ignore = TRUE;
 405                 return NULL;
 406         }
 407
 408         if (data->in_buf == NULL) {
 409                 /* First fragment of the message */
 410                 data->in_buf = wpabuf_alloc(message_length);
 411                 if (data->in_buf == NULL) {
 412                         wpa_printf(MSG_DEBUG, "EAP-WSC: No memory for "
 413                                    "message");
 414                         ret->ignore = TRUE;
 415                         return NULL;
 416                 }
 417                 data->in_op_code = op_code;
 418                 wpabuf_put_data(data->in_buf, buf, len);
 419                 wpa_printf(MSG_DEBUG, "EAP-WSC: Received %lu bytes in first "
 420                            "fragment, waiting for %lu bytes more",
 421                            (unsigned long) len,
 422                            (unsigned long) wpabuf_tailroom(data->in_buf));
 423         }
 424
 425         return eap_wsc_build_frag_ack(id, EAP_CODE_RESPONSE);
 426 }
 427
 428
 429 static struct wpabuf * eap_wsc_process(struct eap_sm *sm, void *priv,
 430                                        struct eap_method_ret *ret,
 431                                        const struct wpabuf *reqData)
 432 {
 433         struct eap_wsc_data *data = priv;
 434         const u8 *start, *pos, *end;
 435         size_t len;
 436         u8 op_code, flags, id;
 437         u16 message_length = 0;
 438         enum wps_process_res res;
 439         struct wpabuf tmpbuf;
 440         struct wpabuf *r;
 441
 442         pos = eap_hdr_validate(EAP_VENDOR_WFA, EAP_VENDOR_TYPE_WSC, reqData,
 443                                &len);
 444         if (pos == NULL || len < 2) {
 445                 ret->ignore = TRUE;
 446                 return NULL;
 447         }
 448
 449         id = eap_get_id(reqData);
 450
 451         start = pos;
 452         end = start + len;
 453
 454         op_code = *pos++;
 455         flags = *pos++;
 456         if (flags & WSC_FLAGS_LF) {
 457                 if (end - pos < 2) {
 458                         wpa_printf(MSG_DEBUG, "EAP-WSC: Message underflow");
 459                         ret->ignore = TRUE;
 460                         return NULL;
 461                 }
 462                 message_length = WPA_GET_BE16(pos);
 463                 pos += 2;
 464
 465                 if (message_length < end - pos || message_length > 50000) {
 466                         wpa_printf(MSG_DEBUG, "EAP-WSC: Invalid Message "
 467                                    "Length");
 468                         ret->ignore = TRUE;
 469                         return NULL;
 470                 }
 471         }
 472
 473         wpa_printf(MSG_DEBUG, "EAP-WSC: Received packet: Op-Code %d "
 474                    "Flags 0x%x Message Length %d",
 475                    op_code, flags, message_length);
 476
 477         if (data->state == WAIT_FRAG_ACK) {
 478                 if (op_code != WSC_FRAG_ACK) {
 479                         wpa_printf(MSG_DEBUG, "EAP-WSC: Unexpected Op-Code %d "
 480                                    "in WAIT_FRAG_ACK state", op_code);
 481                         ret->ignore = TRUE;
 482                         return NULL;
 483                 }
 484                 wpa_printf(MSG_DEBUG, "EAP-WSC: Fragment acknowledged");
 485                 eap_wsc_state(data, MESG);
 486                 return eap_wsc_build_msg(data, ret, id);
 487         }
 488
 489         if (op_code != WSC_ACK && op_code != WSC_NACK && op_code != WSC_MSG &&
 490             op_code != WSC_Done && op_code != WSC_Start) {
 491                 wpa_printf(MSG_DEBUG, "EAP-WSC: Unexpected Op-Code %d",
 492                            op_code);
 493                 ret->ignore = TRUE;
 494                 return NULL;
 495         }
 496
 497         if (data->state == WAIT_START) {
 498                 if (op_code != WSC_Start) {
 499                         wpa_printf(MSG_DEBUG, "EAP-WSC: Unexpected Op-Code %d "
 500                                    "in WAIT_START state", op_code);
 501                         ret->ignore = TRUE;
 502                         return NULL;
 503                 }
 504                 wpa_printf(MSG_DEBUG, "EAP-WSC: Received start");
 505                 eap_wsc_state(data, MESG);
 506                 /* Start message has empty payload, skip processing */
 507                 goto send_msg;
 508         } else if (op_code == WSC_Start) {
 509                 wpa_printf(MSG_DEBUG, "EAP-WSC: Unexpected Op-Code %d",
 510                            op_code);
 511                 ret->ignore = TRUE;
 512                 return NULL;
 513         }
 514
 515         if (data->in_buf &&
 516             eap_wsc_process_cont(data, pos, end - pos, op_code) < 0) {
 517                 ret->ignore = TRUE;
 518                 return NULL;
 519         }
 520
 521         if (flags & WSC_FLAGS_MF) {
 522                 return eap_wsc_process_fragment(data, ret, id, flags, op_code,
 523                                                 message_length, pos,
 524                                                 end - pos);
 525         }
 526
 527         if (data->in_buf == NULL) {
 528                 /* Wrap unfragmented messages as wpabuf without extra copy */
 529                 wpabuf_set(&tmpbuf, pos, end - pos);
 530                 data->in_buf = &tmpbuf;
 531         }
 532
 533         res = wps_process_msg(data->wps, op_code, data->in_buf);
 534         switch (res) {
 535         case WPS_DONE:
 536                 wpa_printf(MSG_DEBUG, "EAP-WSC: WPS processing completed "
 537                            "successfully - wait for EAP failure");
 538                 eap_wsc_state(data, FAIL);
 539                 break;
 540         case WPS_CONTINUE:
 541                 eap_wsc_state(data, MESG);
 542                 break;
 543         case WPS_FAILURE:
 544         case WPS_PENDING:
 545                 wpa_printf(MSG_DEBUG, "EAP-WSC: WPS processing failed");
 546                 eap_wsc_state(data, FAIL);
 547                 break;
 548         }
 549
 550         if (data->in_buf != &tmpbuf)
 551                 wpabuf_free(data->in_buf);
 552         data->in_buf = NULL;
 553
 554 send_msg:
 555         if (data->out_buf == NULL) {
 556                 data->out_buf = wps_get_msg(data->wps, &data->out_op_code);
 557                 if (data->out_buf == NULL) {
 558                         wpa_printf(MSG_DEBUG, "EAP-WSC: Failed to receive "
 559                                    "message from WPS");
 560                         eap_wsc_state(data, FAIL);
 561                         ret->methodState = METHOD_DONE;
 562                         ret->decision = DECISION_FAIL;
 563                         return NULL;
 564                 }
 565                 data->out_used = 0;
 566         }
 567
 568         eap_wsc_state(data, MESG);
 569         r = eap_wsc_build_msg(data, ret, id);
 570         if (data->state == FAIL && ret->methodState == METHOD_DONE) {
 571                 /* Use reduced client timeout for WPS to avoid long wait */
 572                 if (sm->ClientTimeout > 2)
 573                         sm->ClientTimeout = 2;
 574         }
 575         return r;
 576 }
 577
 578
 579 int eap_peer_wsc_register(void)
 580 {
 581         struct eap_method *eap;
 582         int ret;
 583
 584         eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
 585                                     EAP_VENDOR_WFA, EAP_VENDOR_TYPE_WSC,
 586                                     "WSC");
 587         if (eap == NULL)
 588                 return -1;
 589
 590         eap->init = eap_wsc_init;
 591         eap->deinit = eap_wsc_deinit;
 592         eap->process = eap_wsc_process;
 593
 594         ret = eap_peer_method_register(eap);
 595         if (ret)
 596                 eap_peer_method_free(eap);
 597         return ret;
 598 }