contrib/hostapd/src/eap_server/eap_wsc.c

   1 /*
   2  * EAP-WSC server for Wi-Fi Protected Setup
   3  * Copyright (c) 2007-2008, 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 "eloop.h"
  19 #include "eap_i.h"
  20 #include "eap_common/eap_wsc_common.h"
  21 #include "wps/wps.h"
  22
  23
  24 struct eap_wsc_data {
  25         enum { START, MSG, FRAG_ACK, WAIT_FRAG_ACK, DONE, FAIL } state;
  26         int registrar;
  27         struct wpabuf *in_buf;
  28         struct wpabuf *out_buf;
  29         enum wsc_op_code in_op_code, out_op_code;
  30         size_t out_used;
  31         size_t fragment_size;
  32         struct wps_data *wps;
  33         int ext_reg_timeout;
  34 };
  35
  36
  37 static const char * eap_wsc_state_txt(int state)
  38 {
  39         switch (state) {
  40         case START:
  41                 return "START";
  42         case MSG:
  43                 return "MSG";
  44         case FRAG_ACK:
  45                 return "FRAG_ACK";
  46         case WAIT_FRAG_ACK:
  47                 return "WAIT_FRAG_ACK";
  48         case DONE:
  49                 return "DONE";
  50         case FAIL:
  51                 return "FAIL";
  52         default:
  53                 return "?";
  54         }
  55 }
  56
  57
  58 static void eap_wsc_state(struct eap_wsc_data *data, int state)
  59 {
  60         wpa_printf(MSG_DEBUG, "EAP-WSC: %s -> %s",
  61                    eap_wsc_state_txt(data->state),
  62                    eap_wsc_state_txt(state));
  63         data->state = state;
  64 }
  65
  66
  67 static void eap_wsc_ext_reg_timeout(void *eloop_ctx, void *timeout_ctx)
  68 {
  69         struct eap_sm *sm = eloop_ctx;
  70         struct eap_wsc_data *data = timeout_ctx;
  71
  72         if (sm->method_pending != METHOD_PENDING_WAIT)
  73                 return;
  74
  75         wpa_printf(MSG_DEBUG, "EAP-WSC: Timeout while waiting for an External "
  76                    "Registrar");
  77         data->ext_reg_timeout = 1;
  78         eap_sm_pending_cb(sm);
  79 }
  80
  81
  82 static void * eap_wsc_init(struct eap_sm *sm)
  83 {
  84         struct eap_wsc_data *data;
  85         int registrar;
  86         struct wps_config cfg;
  87
  88         if (sm->identity && sm->identity_len == WSC_ID_REGISTRAR_LEN &&
  89             os_memcmp(sm->identity, WSC_ID_REGISTRAR, WSC_ID_REGISTRAR_LEN) ==
  90             0)
  91                 registrar = 0; /* Supplicant is Registrar */
  92         else if (sm->identity && sm->identity_len == WSC_ID_ENROLLEE_LEN &&
  93                  os_memcmp(sm->identity, WSC_ID_ENROLLEE, WSC_ID_ENROLLEE_LEN)
  94                  == 0)
  95                 registrar = 1; /* Supplicant is Enrollee */
  96         else {
  97                 wpa_hexdump_ascii(MSG_INFO, "EAP-WSC: Unexpected identity",
  98                                   sm->identity, sm->identity_len);
  99                 return NULL;
 100         }
 101
 102         data = os_zalloc(sizeof(*data));
 103         if (data == NULL)
 104                 return NULL;
 105         data->state = registrar ? START : MSG;
 106         data->registrar = registrar;
 107
 108         os_memset(&cfg, 0, sizeof(cfg));
 109         cfg.wps = sm->wps;
 110         cfg.registrar = registrar;
 111         if (registrar) {
 112                 if (sm->wps == NULL || sm->wps->registrar == NULL) {
 113                         wpa_printf(MSG_INFO, "EAP-WSC: WPS Registrar not "
 114                                    "initialized");
 115                         os_free(data);
 116                         return NULL;
 117                 }
 118         } else {
 119                 if (sm->user == NULL || sm->user->password == NULL) {
 120                         wpa_printf(MSG_INFO, "EAP-WSC: No AP PIN (password) "
 121                                    "configured for Enrollee functionality");
 122                         os_free(data);
 123                         return NULL;
 124                 }
 125                 cfg.pin = sm->user->password;
 126                 cfg.pin_len = sm->user->password_len;
 127         }
 128         cfg.assoc_wps_ie = sm->assoc_wps_ie;
 129         data->wps = wps_init(&cfg);
 130         if (data->wps == NULL) {
 131                 os_free(data);
 132                 return NULL;
 133         }
 134         data->fragment_size = WSC_FRAGMENT_SIZE;
 135
 136         return data;
 137 }
 138
 139
 140 static void eap_wsc_reset(struct eap_sm *sm, void *priv)
 141 {
 142         struct eap_wsc_data *data = priv;
 143         eloop_cancel_timeout(eap_wsc_ext_reg_timeout, sm, data);
 144         wpabuf_free(data->in_buf);
 145         wpabuf_free(data->out_buf);
 146         wps_deinit(data->wps);
 147         os_free(data);
 148 }
 149
 150
 151 static struct wpabuf * eap_wsc_build_start(struct eap_sm *sm,
 152                                            struct eap_wsc_data *data, u8 id)
 153 {
 154         struct wpabuf *req;
 155
 156         req = eap_msg_alloc(EAP_VENDOR_WFA, EAP_VENDOR_TYPE_WSC, 2,
 157                             EAP_CODE_REQUEST, id);
 158         if (req == NULL) {
 159                 wpa_printf(MSG_ERROR, "EAP-WSC: Failed to allocate memory for "
 160                            "request");
 161                 return NULL;
 162         }
 163
 164         wpa_printf(MSG_DEBUG, "EAP-WSC: Send WSC/Start");
 165         wpabuf_put_u8(req, WSC_Start); /* Op-Code */
 166         wpabuf_put_u8(req, 0); /* Flags */
 167
 168         return req;
 169 }
 170
 171
 172 static struct wpabuf * eap_wsc_build_msg(struct eap_wsc_data *data, u8 id)
 173 {
 174         struct wpabuf *req;
 175         u8 flags;
 176         size_t send_len, plen;
 177
 178         flags = 0;
 179         send_len = wpabuf_len(data->out_buf) - data->out_used;
 180         if (2 + send_len > data->fragment_size) {
 181                 send_len = data->fragment_size - 2;
 182                 flags |= WSC_FLAGS_MF;
 183                 if (data->out_used == 0) {
 184                         flags |= WSC_FLAGS_LF;
 185                         send_len -= 2;
 186                 }
 187         }
 188         plen = 2 + send_len;
 189         if (flags & WSC_FLAGS_LF)
 190                 plen += 2;
 191         req = eap_msg_alloc(EAP_VENDOR_WFA, EAP_VENDOR_TYPE_WSC, plen,
 192                             EAP_CODE_REQUEST, id);
 193         if (req == NULL) {
 194                 wpa_printf(MSG_ERROR, "EAP-WSC: Failed to allocate memory for "
 195                            "request");
 196                 return NULL;
 197         }
 198
 199         wpabuf_put_u8(req, data->out_op_code); /* Op-Code */
 200         wpabuf_put_u8(req, flags); /* Flags */
 201         if (flags & WSC_FLAGS_LF)
 202                 wpabuf_put_be16(req, wpabuf_len(data->out_buf));
 203
 204         wpabuf_put_data(req, wpabuf_head_u8(data->out_buf) + data->out_used,
 205                         send_len);
 206         data->out_used += send_len;
 207
 208         if (data->out_used == wpabuf_len(data->out_buf)) {
 209                 wpa_printf(MSG_DEBUG, "EAP-WSC: Sending out %lu bytes "
 210                            "(message sent completely)",
 211                            (unsigned long) send_len);
 212                 wpabuf_free(data->out_buf);
 213                 data->out_buf = NULL;
 214                 data->out_used = 0;
 215                 eap_wsc_state(data, MSG);
 216         } else {
 217                 wpa_printf(MSG_DEBUG, "EAP-WSC: Sending out %lu bytes "
 218                            "(%lu more to send)", (unsigned long) send_len,
 219                            (unsigned long) wpabuf_len(data->out_buf) -
 220                            data->out_used);
 221                 eap_wsc_state(data, WAIT_FRAG_ACK);
 222         }
 223
 224         return req;
 225 }
 226
 227
 228 static struct wpabuf * eap_wsc_buildReq(struct eap_sm *sm, void *priv, u8 id)
 229 {
 230         struct eap_wsc_data *data = priv;
 231
 232         switch (data->state) {
 233         case START:
 234                 return eap_wsc_build_start(sm, data, id);
 235         case MSG:
 236                 if (data->out_buf == NULL) {
 237                         data->out_buf = wps_get_msg(data->wps,
 238                                                     &data->out_op_code);
 239                         if (data->out_buf == NULL) {
 240                                 wpa_printf(MSG_DEBUG, "EAP-WSC: Failed to "
 241                                            "receive message from WPS");
 242                                 return NULL;
 243                         }
 244                         data->out_used = 0;
 245                 }
 246                 /* pass through */
 247         case WAIT_FRAG_ACK:
 248                 return eap_wsc_build_msg(data, id);
 249         case FRAG_ACK:
 250                 return eap_wsc_build_frag_ack(id, EAP_CODE_REQUEST);
 251         default:
 252                 wpa_printf(MSG_DEBUG, "EAP-WSC: Unexpected state %d in "
 253                            "buildReq", data->state);
 254                 return NULL;
 255         }
 256 }
 257
 258
 259 static Boolean eap_wsc_check(struct eap_sm *sm, void *priv,
 260                              struct wpabuf *respData)
 261 {
 262         const u8 *pos;
 263         size_t len;
 264
 265         pos = eap_hdr_validate(EAP_VENDOR_WFA, EAP_VENDOR_TYPE_WSC,
 266                                respData, &len);
 267         if (pos == NULL || len < 2) {
 268                 wpa_printf(MSG_INFO, "EAP-WSC: Invalid frame");
 269                 return TRUE;
 270         }
 271
 272         return FALSE;
 273 }
 274
 275
 276 static int eap_wsc_process_cont(struct eap_wsc_data *data,
 277                                 const u8 *buf, size_t len, u8 op_code)
 278 {
 279         /* Process continuation of a pending message */
 280         if (op_code != data->in_op_code) {
 281                 wpa_printf(MSG_DEBUG, "EAP-WSC: Unexpected Op-Code %d in "
 282                            "fragment (expected %d)",
 283                            op_code, data->in_op_code);
 284                 eap_wsc_state(data, FAIL);
 285                 return -1;
 286         }
 287
 288         if (len > wpabuf_tailroom(data->in_buf)) {
 289                 wpa_printf(MSG_DEBUG, "EAP-WSC: Fragment overflow");
 290                 eap_wsc_state(data, FAIL);
 291                 return -1;
 292         }
 293
 294         wpabuf_put_data(data->in_buf, buf, len);
 295         wpa_printf(MSG_DEBUG, "EAP-WSC: Received %lu bytes, waiting for %lu "
 296                    "bytes more", (unsigned long) len,
 297                    (unsigned long) wpabuf_tailroom(data->in_buf));
 298
 299         return 0;
 300 }
 301
 302
 303 static int eap_wsc_process_fragment(struct eap_wsc_data *data,
 304                                     u8 flags, u8 op_code, u16 message_length,
 305                                     const u8 *buf, size_t len)
 306 {
 307         /* Process a fragment that is not the last one of the message */
 308         if (data->in_buf == NULL && !(flags & WSC_FLAGS_LF)) {
 309                 wpa_printf(MSG_DEBUG, "EAP-WSC: No Message Length "
 310                            "field in a fragmented packet");
 311                 return -1;
 312         }
 313
 314         if (data->in_buf == NULL) {
 315                 /* First fragment of the message */
 316                 data->in_buf = wpabuf_alloc(message_length);
 317                 if (data->in_buf == NULL) {
 318                         wpa_printf(MSG_DEBUG, "EAP-WSC: No memory for "
 319                                    "message");
 320                         return -1;
 321                 }
 322                 data->in_op_code = op_code;
 323                 wpabuf_put_data(data->in_buf, buf, len);
 324                 wpa_printf(MSG_DEBUG, "EAP-WSC: Received %lu bytes in "
 325                            "first fragment, waiting for %lu bytes more",
 326                            (unsigned long) len,
 327                            (unsigned long) wpabuf_tailroom(data->in_buf));
 328         }
 329
 330         return 0;
 331 }
 332
 333
 334 static void eap_wsc_process(struct eap_sm *sm, void *priv,
 335                             struct wpabuf *respData)
 336 {
 337         struct eap_wsc_data *data = priv;
 338         const u8 *start, *pos, *end;
 339         size_t len;
 340         u8 op_code, flags;
 341         u16 message_length = 0;
 342         enum wps_process_res res;
 343         struct wpabuf tmpbuf;
 344
 345         eloop_cancel_timeout(eap_wsc_ext_reg_timeout, sm, data);
 346         if (data->ext_reg_timeout) {
 347                 eap_wsc_state(data, FAIL);
 348                 return;
 349         }
 350
 351         pos = eap_hdr_validate(EAP_VENDOR_WFA, EAP_VENDOR_TYPE_WSC,
 352                                respData, &len);
 353         if (pos == NULL || len < 2)
 354                 return; /* Should not happen; message already verified */
 355
 356         start = pos;
 357         end = start + len;
 358
 359         op_code = *pos++;
 360         flags = *pos++;
 361         if (flags & WSC_FLAGS_LF) {
 362                 if (end - pos < 2) {
 363                         wpa_printf(MSG_DEBUG, "EAP-WSC: Message underflow");
 364                         return;
 365                 }
 366                 message_length = WPA_GET_BE16(pos);
 367                 pos += 2;
 368
 369                 if (message_length < end - pos) {
 370                         wpa_printf(MSG_DEBUG, "EAP-WSC: Invalid Message "
 371                                    "Length");
 372                         return;
 373                 }
 374         }
 375
 376         wpa_printf(MSG_DEBUG, "EAP-WSC: Received packet: Op-Code %d "
 377                    "Flags 0x%x Message Length %d",
 378                    op_code, flags, message_length);
 379
 380         if (data->state == WAIT_FRAG_ACK) {
 381                 if (op_code != WSC_FRAG_ACK) {
 382                         wpa_printf(MSG_DEBUG, "EAP-WSC: Unexpected Op-Code %d "
 383                                    "in WAIT_FRAG_ACK state", op_code);
 384                         eap_wsc_state(data, FAIL);
 385                         return;
 386                 }
 387                 wpa_printf(MSG_DEBUG, "EAP-WSC: Fragment acknowledged");
 388                 eap_wsc_state(data, MSG);
 389                 return;
 390         }
 391
 392         if (op_code != WSC_ACK && op_code != WSC_NACK && op_code != WSC_MSG &&
 393             op_code != WSC_Done) {
 394                 wpa_printf(MSG_DEBUG, "EAP-WSC: Unexpected Op-Code %d",
 395                            op_code);
 396                 eap_wsc_state(data, FAIL);
 397                 return;
 398         }
 399
 400         if (data->in_buf &&
 401             eap_wsc_process_cont(data, pos, end - pos, op_code) < 0) {
 402                 eap_wsc_state(data, FAIL);
 403                 return;
 404         }
 405
 406         if (flags & WSC_FLAGS_MF) {
 407                 if (eap_wsc_process_fragment(data, flags, op_code,
 408                                              message_length, pos, end - pos) <
 409                     0)
 410                         eap_wsc_state(data, FAIL);
 411                 else
 412                         eap_wsc_state(data, FRAG_ACK);
 413                 return;
 414         }
 415
 416         if (data->in_buf == NULL) {
 417                 /* Wrap unfragmented messages as wpabuf without extra copy */
 418                 wpabuf_set(&tmpbuf, pos, end - pos);
 419                 data->in_buf = &tmpbuf;
 420         }
 421
 422         res = wps_process_msg(data->wps, op_code, data->in_buf);
 423         switch (res) {
 424         case WPS_DONE:
 425                 wpa_printf(MSG_DEBUG, "EAP-WSC: WPS processing completed "
 426                            "successfully - report EAP failure");
 427                 eap_wsc_state(data, FAIL);
 428                 break;
 429         case WPS_CONTINUE:
 430                 eap_wsc_state(data, MSG);
 431                 break;
 432         case WPS_FAILURE:
 433                 wpa_printf(MSG_DEBUG, "EAP-WSC: WPS processing failed");
 434                 eap_wsc_state(data, FAIL);
 435                 break;
 436         case WPS_PENDING:
 437                 eap_wsc_state(data, MSG);
 438                 sm->method_pending = METHOD_PENDING_WAIT;
 439                 eloop_cancel_timeout(eap_wsc_ext_reg_timeout, sm, data);
 440                 eloop_register_timeout(5, 0, eap_wsc_ext_reg_timeout,
 441                                        sm, data);
 442                 break;
 443         }
 444
 445         if (data->in_buf != &tmpbuf)
 446                 wpabuf_free(data->in_buf);
 447         data->in_buf = NULL;
 448 }
 449
 450
 451 static Boolean eap_wsc_isDone(struct eap_sm *sm, void *priv)
 452 {
 453         struct eap_wsc_data *data = priv;
 454         return data->state == FAIL;
 455 }
 456
 457
 458 static Boolean eap_wsc_isSuccess(struct eap_sm *sm, void *priv)
 459 {
 460         /* EAP-WSC will always result in EAP-Failure */
 461         return FALSE;
 462 }
 463
 464
 465 static int eap_wsc_getTimeout(struct eap_sm *sm, void *priv)
 466 {
 467         /* Recommended retransmit times: retransmit timeout 5 seconds,
 468          * per-message timeout 15 seconds, i.e., 3 tries. */
 469         sm->MaxRetrans = 2; /* total 3 attempts */
 470         return 5;
 471 }
 472
 473
 474 int eap_server_wsc_register(void)
 475 {
 476         struct eap_method *eap;
 477         int ret;
 478
 479         eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
 480                                       EAP_VENDOR_WFA, EAP_VENDOR_TYPE_WSC,
 481                                       "WSC");
 482         if (eap == NULL)
 483                 return -1;
 484
 485         eap->init = eap_wsc_init;
 486         eap->reset = eap_wsc_reset;
 487         eap->buildReq = eap_wsc_buildReq;
 488         eap->check = eap_wsc_check;
 489         eap->process = eap_wsc_process;
 490         eap->isDone = eap_wsc_isDone;
 491         eap->isSuccess = eap_wsc_isSuccess;
 492         eap->getTimeout = eap_wsc_getTimeout;
 493
 494         ret = eap_server_method_register(eap);
 495         if (ret)
 496                 eap_server_method_free(eap);
 497         return ret;
 498 }