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