src/eap_peer/eap_wsc.c

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