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 program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation.
   8  *
   9  * Alternatively, this software may be distributed under the terms of BSD
  10  * license.
  11  *
  12  * See README and COPYING for more details.
  13  */
  14
  15 #include "includes.h"
  16
  17 #include "common.h"
  18 #include "uuid.h"
  19 #include "eap_i.h"
  20 #include "eap_common/eap_wsc_common.h"
  21 #include "wps/wps.h"
  22 #include "wps/wps_defs.h"
  23
  24
  25 struct eap_wsc_data {
  26         enum { WAIT_START, MESG, FRAG_ACK, WAIT_FRAG_ACK, DONE, FAIL } state;
  27         int registrar;
  28         struct wpabuf *in_buf;
  29         struct wpabuf *out_buf;
  30         enum wsc_op_code in_op_code, out_op_code;
  31         size_t out_used;
  32         size_t fragment_size;
  33         struct wps_data *wps;
  34         struct wps_context *wps_ctx;
  35 };
  36
  37
  38 static const char * eap_wsc_state_txt(int state)
  39 {
  40         switch (state) {
  41         case WAIT_START:
  42                 return "WAIT_START";
  43         case MESG:
  44                 return "MESG";
  45         case FRAG_ACK:
  46                 return "FRAG_ACK";
  47         case WAIT_FRAG_ACK:
  48                 return "WAIT_FRAG_ACK";
  49         case DONE:
  50                 return "DONE";
  51         case FAIL:
  52                 return "FAIL";
  53         default:
  54                 return "?";
  55         }
  56 }
  57
  58
  59 static void eap_wsc_state(struct eap_wsc_data *data, int state)
  60 {
  61         wpa_printf(MSG_DEBUG, "EAP-WSC: %s -> %s",
  62                    eap_wsc_state_txt(data->state),
  63                    eap_wsc_state_txt(state));
  64         data->state = state;
  65 }
  66
  67
  68 static int eap_wsc_new_ap_settings(struct wps_credential *cred,
  69                                    const char *params)
  70 {
  71         const char *pos, *end;
  72         size_t len;
  73
  74         os_memset(cred, 0, sizeof(*cred));
  75
  76         pos = os_strstr(params, "new_ssid=");
  77         if (pos == NULL)
  78                 return 0;
  79         pos += 9;
  80         end = os_strchr(pos, ' ');
  81         if (end == NULL)
  82                 len = os_strlen(pos);
  83         else
  84                 len = end - pos;
  85         if ((len & 1) || len > 2 * sizeof(cred->ssid) ||
  86             hexstr2bin(pos, cred->ssid, len / 2))
  87                 return -1;
  88         cred->ssid_len = len / 2;
  89
  90         pos = os_strstr(params, "new_auth=");
  91         if (pos == NULL)
  92                 return -1;
  93         if (os_strncmp(pos + 9, "OPEN", 4) == 0)
  94                 cred->auth_type = WPS_AUTH_OPEN;
  95         else if (os_strncmp(pos + 9, "WPAPSK", 6) == 0)
  96                 cred->auth_type = WPS_AUTH_WPAPSK;
  97         else if (os_strncmp(pos + 9, "WPA2PSK", 7) == 0)
  98                 cred->auth_type = WPS_AUTH_WPA2PSK;
  99         else
 100                 return -1;
 101
 102         pos = os_strstr(params, "new_encr=");
 103         if (pos == NULL)
 104                 return -1;
 105         if (os_strncmp(pos + 9, "NONE", 4) == 0)
 106                 cred->encr_type = WPS_ENCR_NONE;
 107         else if (os_strncmp(pos + 9, "WEP", 3) == 0)
 108                 cred->encr_type = WPS_ENCR_WEP;
 109         else if (os_strncmp(pos + 9, "TKIP", 4) == 0)
 110                 cred->encr_type = WPS_ENCR_TKIP;
 111         else if (os_strncmp(pos + 9, "CCMP", 4) == 0)
 112                 cred->encr_type = WPS_ENCR_AES;
 113         else
 114                 return -1;
 115
 116         pos = os_strstr(params, "new_key=");
 117         if (pos == NULL)
 118                 return 0;
 119         pos += 8;
 120         end = os_strchr(pos, ' ');
 121         if (end == NULL)
 122                 len = os_strlen(pos);
 123         else
 124                 len = end - pos;
 125         if ((len & 1) || len > 2 * sizeof(cred->key) ||
 126             hexstr2bin(pos, cred->key, len / 2))
 127                 return -1;
 128         cred->key_len = len / 2;
 129
 130         return 1;
 131 }
 132
 133
 134 static void * eap_wsc_init(struct eap_sm *sm)
 135 {
 136         struct eap_wsc_data *data;
 137         const u8 *identity;
 138         size_t identity_len;
 139         int registrar;
 140         struct wps_config cfg;
 141         const char *pos;
 142         const char *phase1;
 143         struct wps_context *wps;
 144         struct wps_credential new_ap_settings;
 145         int res;
 146
 147         wps = sm->wps;
 148         if (wps == NULL) {
 149                 wpa_printf(MSG_ERROR, "EAP-WSC: WPS context not available");
 150                 return NULL;
 151         }
 152
 153         identity = eap_get_config_identity(sm, &identity_len);
 154
 155         if (identity && identity_len == WSC_ID_REGISTRAR_LEN &&
 156             os_memcmp(identity, WSC_ID_REGISTRAR, WSC_ID_REGISTRAR_LEN) == 0)
 157                 registrar = 1; /* Supplicant is Registrar */
 158         else if (identity && identity_len == WSC_ID_ENROLLEE_LEN &&
 159             os_memcmp(identity, WSC_ID_ENROLLEE, WSC_ID_ENROLLEE_LEN) == 0)
 160                 registrar = 0; /* Supplicant is Enrollee */
 161         else {
 162                 wpa_hexdump_ascii(MSG_INFO, "EAP-WSC: Unexpected identity",
 163                                   identity, identity_len);
 164                 return NULL;
 165         }
 166
 167         data = os_zalloc(sizeof(*data));
 168         if (data == NULL)
 169                 return NULL;
 170         data->state = registrar ? MESG : WAIT_START;
 171         data->registrar = registrar;
 172         data->wps_ctx = wps;
 173
 174         os_memset(&cfg, 0, sizeof(cfg));
 175         cfg.wps = wps;
 176         cfg.registrar = registrar;
 177
 178         phase1 = eap_get_config_phase1(sm);
 179         if (phase1 == NULL) {
 180                 wpa_printf(MSG_INFO, "EAP-WSC: phase1 configuration data not "
 181                            "set");
 182                 os_free(data);
 183                 return NULL;
 184         }
 185
 186         pos = os_strstr(phase1, "pin=");
 187         if (pos) {
 188                 pos += 4;
 189                 cfg.pin = (const u8 *) pos;
 190                 while (*pos != '\0' && *pos != ' ')
 191                         pos++;
 192                 cfg.pin_len = pos - (const char *) cfg.pin;
 193         } else {
 194                 pos = os_strstr(phase1, "pbc=1");
 195                 if (pos)
 196                         cfg.pbc = 1;
 197         }
 198
 199         if (cfg.pin == NULL && !cfg.pbc) {
 200                 wpa_printf(MSG_INFO, "EAP-WSC: PIN or PBC not set in phase1 "
 201                            "configuration data");
 202                 os_free(data);
 203                 return NULL;
 204         }
 205
 206         res = eap_wsc_new_ap_settings(&new_ap_settings, phase1);
 207         if (res < 0) {
 208                 os_free(data);
 209                 return NULL;
 210         }
 211         if (res == 1) {
 212                 wpa_printf(MSG_DEBUG, "EAP-WSC: Provide new AP settings for "
 213                            "WPS");
 214                 cfg.new_ap_settings = &new_ap_settings;
 215         }
 216
 217         data->wps = wps_init(&cfg);
 218         if (data->wps == NULL) {
 219                 os_free(data);
 220                 return NULL;
 221         }
 222         res = eap_get_config_fragment_size(sm);
 223         if (res > 0)
 224                 data->fragment_size = res;
 225         else
 226                 data->fragment_size = WSC_FRAGMENT_SIZE;
 227         wpa_printf(MSG_DEBUG, "EAP-WSC: Fragment size limit %u",
 228                    (unsigned int) data->fragment_size);
 229
 230         if (registrar && cfg.pin) {
 231                 wps_registrar_add_pin(data->wps_ctx->registrar, NULL, NULL,
 232                                       cfg.pin, cfg.pin_len, 0);
 233         }
 234
 235         /* Use reduced client timeout for WPS to avoid long wait */
 236         if (sm->ClientTimeout > 30)
 237                 sm->ClientTimeout = 30;
 238
 239         return data;
 240 }
 241
 242
 243 static void eap_wsc_deinit(struct eap_sm *sm, void *priv)
 244 {
 245         struct eap_wsc_data *data = priv;
 246         wpabuf_free(data->in_buf);
 247         wpabuf_free(data->out_buf);
 248         wps_deinit(data->wps);
 249         os_free(data->wps_ctx->network_key);
 250         data->wps_ctx->network_key = NULL;
 251         os_free(data);
 252 }
 253
 254
 255 static struct wpabuf * eap_wsc_build_msg(struct eap_wsc_data *data,
 256                                          struct eap_method_ret *ret, u8 id)
 257 {
 258         struct wpabuf *resp;
 259         u8 flags;
 260         size_t send_len, plen;
 261
 262         ret->ignore = FALSE;
 263         wpa_printf(MSG_DEBUG, "EAP-WSC: Generating Response");
 264         ret->allowNotifications = TRUE;
 265
 266         flags = 0;
 267         send_len = wpabuf_len(data->out_buf) - data->out_used;
 268         if (2 + send_len > data->fragment_size) {
 269                 send_len = data->fragment_size - 2;
 270                 flags |= WSC_FLAGS_MF;
 271                 if (data->out_used == 0) {
 272                         flags |= WSC_FLAGS_LF;
 273                         send_len -= 2;
 274                 }
 275         }
 276         plen = 2 + send_len;
 277         if (flags & WSC_FLAGS_LF)
 278                 plen += 2;
 279         resp = eap_msg_alloc(EAP_VENDOR_WFA, EAP_VENDOR_TYPE_WSC, plen,
 280                              EAP_CODE_RESPONSE, id);
 281         if (resp == NULL)
 282                 return NULL;
 283
 284         wpabuf_put_u8(resp, data->out_op_code); /* Op-Code */
 285         wpabuf_put_u8(resp, flags); /* Flags */
 286         if (flags & WSC_FLAGS_LF)
 287                 wpabuf_put_be16(resp, wpabuf_len(data->out_buf));
 288
 289         wpabuf_put_data(resp, wpabuf_head_u8(data->out_buf) + data->out_used,
 290                         send_len);
 291         data->out_used += send_len;
 292
 293         ret->methodState = METHOD_MAY_CONT;
 294         ret->decision = DECISION_FAIL;
 295
 296         if (data->out_used == wpabuf_len(data->out_buf)) {
 297                 wpa_printf(MSG_DEBUG, "EAP-WSC: Sending out %lu bytes "
 298                            "(message sent completely)",
 299                            (unsigned long) send_len);
 300                 wpabuf_free(data->out_buf);
 301                 data->out_buf = NULL;
 302                 data->out_used = 0;
 303                 if ((data->state == FAIL && data->out_op_code == WSC_ACK) ||
 304                     data->out_op_code == WSC_NACK ||
 305                     data->out_op_code == WSC_Done) {
 306                         eap_wsc_state(data, FAIL);
 307                         ret->methodState = METHOD_DONE;
 308                 } else
 309                         eap_wsc_state(data, MESG);
 310         } else {
 311                 wpa_printf(MSG_DEBUG, "EAP-WSC: Sending out %lu bytes "
 312                            "(%lu more to send)", (unsigned long) send_len,
 313                            (unsigned long) wpabuf_len(data->out_buf) -
 314                            data->out_used);
 315                 eap_wsc_state(data, WAIT_FRAG_ACK);
 316         }
 317
 318         return resp;
 319 }
 320
 321
 322 static int eap_wsc_process_cont(struct eap_wsc_data *data,
 323                                 const u8 *buf, size_t len, u8 op_code)
 324 {
 325         /* Process continuation of a pending message */
 326         if (op_code != data->in_op_code) {
 327                 wpa_printf(MSG_DEBUG, "EAP-WSC: Unexpected Op-Code %d in "
 328                            "fragment (expected %d)",
 329                            op_code, data->in_op_code);
 330                 return -1;
 331         }
 332
 333         if (len > wpabuf_tailroom(data->in_buf)) {
 334                 wpa_printf(MSG_DEBUG, "EAP-WSC: Fragment overflow");
 335                 eap_wsc_state(data, FAIL);
 336                 return -1;
 337         }
 338
 339         wpabuf_put_data(data->in_buf, buf, len);
 340         wpa_printf(MSG_DEBUG, "EAP-WSC: Received %lu bytes, waiting "
 341                    "for %lu bytes more", (unsigned long) len,
 342                    (unsigned long) wpabuf_tailroom(data->in_buf));
 343
 344         return 0;
 345 }
 346
 347
 348 static struct wpabuf * eap_wsc_process_fragment(struct eap_wsc_data *data,
 349                                                 struct eap_method_ret *ret,
 350                                                 u8 id, u8 flags, u8 op_code,
 351                                                 u16 message_length,
 352                                                 const u8 *buf, size_t len)
 353 {
 354         /* Process a fragment that is not the last one of the message */
 355         if (data->in_buf == NULL && !(flags & WSC_FLAGS_LF)) {
 356                 wpa_printf(MSG_DEBUG, "EAP-WSC: No Message Length field in a "
 357                            "fragmented packet");
 358                 ret->ignore = TRUE;
 359                 return NULL;
 360         }
 361
 362         if (data->in_buf == NULL) {
 363                 /* First fragment of the message */
 364                 data->in_buf = wpabuf_alloc(message_length);
 365                 if (data->in_buf == NULL) {
 366                         wpa_printf(MSG_DEBUG, "EAP-WSC: No memory for "
 367                                    "message");
 368                         ret->ignore = TRUE;
 369                         return NULL;
 370                 }
 371                 data->in_op_code = op_code;
 372                 wpabuf_put_data(data->in_buf, buf, len);
 373                 wpa_printf(MSG_DEBUG, "EAP-WSC: Received %lu bytes in first "
 374                            "fragment, waiting for %lu bytes more",
 375                            (unsigned long) len,
 376                            (unsigned long) wpabuf_tailroom(data->in_buf));
 377         }
 378
 379         return eap_wsc_build_frag_ack(id, EAP_CODE_RESPONSE);
 380 }
 381
 382
 383 static struct wpabuf * eap_wsc_process(struct eap_sm *sm, void *priv,
 384                                        struct eap_method_ret *ret,
 385                                        const struct wpabuf *reqData)
 386 {
 387         struct eap_wsc_data *data = priv;
 388         const u8 *start, *pos, *end;
 389         size_t len;
 390         u8 op_code, flags, id;
 391         u16 message_length = 0;
 392         enum wps_process_res res;
 393         struct wpabuf tmpbuf;
 394         struct wpabuf *r;
 395
 396         pos = eap_hdr_validate(EAP_VENDOR_WFA, EAP_VENDOR_TYPE_WSC, reqData,
 397                                &len);
 398         if (pos == NULL || len < 2) {
 399                 ret->ignore = TRUE;
 400                 return NULL;
 401         }
 402
 403         id = eap_get_id(reqData);
 404
 405         start = pos;
 406         end = start + len;
 407
 408         op_code = *pos++;
 409         flags = *pos++;
 410         if (flags & WSC_FLAGS_LF) {
 411                 if (end - pos < 2) {
 412                         wpa_printf(MSG_DEBUG, "EAP-WSC: Message underflow");
 413                         ret->ignore = TRUE;
 414                         return NULL;
 415                 }
 416                 message_length = WPA_GET_BE16(pos);
 417                 pos += 2;
 418
 419                 if (message_length < end - pos) {
 420                         wpa_printf(MSG_DEBUG, "EAP-WSC: Invalid Message "
 421                                    "Length");
 422                         ret->ignore = TRUE;
 423                         return NULL;
 424                 }
 425         }
 426
 427         wpa_printf(MSG_DEBUG, "EAP-WSC: Received packet: Op-Code %d "
 428                    "Flags 0x%x Message Length %d",
 429                    op_code, flags, message_length);
 430
 431         if (data->state == WAIT_FRAG_ACK) {
 432                 if (op_code != WSC_FRAG_ACK) {
 433                         wpa_printf(MSG_DEBUG, "EAP-WSC: Unexpected Op-Code %d "
 434                                    "in WAIT_FRAG_ACK state", op_code);
 435                         ret->ignore = TRUE;
 436                         return NULL;
 437                 }
 438                 wpa_printf(MSG_DEBUG, "EAP-WSC: Fragment acknowledged");
 439                 eap_wsc_state(data, MESG);
 440                 return eap_wsc_build_msg(data, ret, id);
 441         }
 442
 443         if (op_code != WSC_ACK && op_code != WSC_NACK && op_code != WSC_MSG &&
 444             op_code != WSC_Done && op_code != WSC_Start) {
 445                 wpa_printf(MSG_DEBUG, "EAP-WSC: Unexpected Op-Code %d",
 446                            op_code);
 447                 ret->ignore = TRUE;
 448                 return NULL;
 449         }
 450
 451         if (data->state == WAIT_START) {
 452                 if (op_code != WSC_Start) {
 453                         wpa_printf(MSG_DEBUG, "EAP-WSC: Unexpected Op-Code %d "
 454                                    "in WAIT_START state", op_code);
 455                         ret->ignore = TRUE;
 456                         return NULL;
 457                 }
 458                 wpa_printf(MSG_DEBUG, "EAP-WSC: Received start");
 459                 eap_wsc_state(data, MESG);
 460                 /* Start message has empty payload, skip processing */
 461                 goto send_msg;
 462         } else if (op_code == WSC_Start) {
 463                 wpa_printf(MSG_DEBUG, "EAP-WSC: Unexpected Op-Code %d",
 464                            op_code);
 465                 ret->ignore = TRUE;
 466                 return NULL;
 467         }
 468
 469         if (data->in_buf &&
 470             eap_wsc_process_cont(data, pos, end - pos, op_code) < 0) {
 471                 ret->ignore = TRUE;
 472                 return NULL;
 473         }
 474
 475         if (flags & WSC_FLAGS_MF) {
 476                 return eap_wsc_process_fragment(data, ret, id, flags, op_code,
 477                                                 message_length, pos,
 478                                                 end - pos);
 479         }
 480
 481         if (data->in_buf == NULL) {
 482                 /* Wrap unfragmented messages as wpabuf without extra copy */
 483                 wpabuf_set(&tmpbuf, pos, end - pos);
 484                 data->in_buf = &tmpbuf;
 485         }
 486
 487         res = wps_process_msg(data->wps, op_code, data->in_buf);
 488         switch (res) {
 489         case WPS_DONE:
 490                 wpa_printf(MSG_DEBUG, "EAP-WSC: WPS processing completed "
 491                            "successfully - wait for EAP failure");
 492                 eap_wsc_state(data, FAIL);
 493                 break;
 494         case WPS_CONTINUE:
 495                 eap_wsc_state(data, MESG);
 496                 break;
 497         case WPS_FAILURE:
 498         case WPS_PENDING:
 499                 wpa_printf(MSG_DEBUG, "EAP-WSC: WPS processing failed");
 500                 eap_wsc_state(data, FAIL);
 501                 break;
 502         }
 503
 504         if (data->in_buf != &tmpbuf)
 505                 wpabuf_free(data->in_buf);
 506         data->in_buf = NULL;
 507
 508 send_msg:
 509         if (data->out_buf == NULL) {
 510                 data->out_buf = wps_get_msg(data->wps, &data->out_op_code);
 511                 if (data->out_buf == NULL) {
 512                         wpa_printf(MSG_DEBUG, "EAP-WSC: Failed to receive "
 513                                    "message from WPS");
 514                         return NULL;
 515                 }
 516                 data->out_used = 0;
 517         }
 518
 519         eap_wsc_state(data, MESG);
 520         r = eap_wsc_build_msg(data, ret, id);
 521         if (data->state == FAIL && ret->methodState == METHOD_DONE) {
 522                 /* Use reduced client timeout for WPS to avoid long wait */
 523                 if (sm->ClientTimeout > 2)
 524                         sm->ClientTimeout = 2;
 525         }
 526         return r;
 527 }
 528
 529
 530 int eap_peer_wsc_register(void)
 531 {
 532         struct eap_method *eap;
 533         int ret;
 534
 535         eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
 536                                     EAP_VENDOR_WFA, EAP_VENDOR_TYPE_WSC,
 537                                     "WSC");
 538         if (eap == NULL)
 539                 return -1;
 540
 541         eap->init = eap_wsc_init;
 542         eap->deinit = eap_wsc_deinit;
 543         eap->process = eap_wsc_process;
 544
 545         ret = eap_peer_method_register(eap);
 546         if (ret)
 547                 eap_peer_method_free(eap);
 548         return ret;
 549 }