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