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