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         data->fragment_size = WSC_FRAGMENT_SIZE;
 223
 224         if (registrar && cfg.pin) {
 225                 wps_registrar_add_pin(data->wps_ctx->registrar, NULL,
 226                                       cfg.pin, cfg.pin_len, 0);
 227         }
 228
 229         return data;
 230 }
 231
 232
 233 static void eap_wsc_deinit(struct eap_sm *sm, void *priv)
 234 {
 235         struct eap_wsc_data *data = priv;
 236         wpabuf_free(data->in_buf);
 237         wpabuf_free(data->out_buf);
 238         wps_deinit(data->wps);
 239         os_free(data->wps_ctx->network_key);
 240         data->wps_ctx->network_key = NULL;
 241         os_free(data);
 242 }
 243
 244
 245 static struct wpabuf * eap_wsc_build_msg(struct eap_wsc_data *data,
 246                                          struct eap_method_ret *ret, u8 id)
 247 {
 248         struct wpabuf *resp;
 249         u8 flags;
 250         size_t send_len, plen;
 251
 252         ret->ignore = FALSE;
 253         wpa_printf(MSG_DEBUG, "EAP-WSC: Generating Response");
 254         ret->allowNotifications = TRUE;
 255
 256         flags = 0;
 257         send_len = wpabuf_len(data->out_buf) - data->out_used;
 258         if (2 + send_len > data->fragment_size) {
 259                 send_len = data->fragment_size - 2;
 260                 flags |= WSC_FLAGS_MF;
 261                 if (data->out_used == 0) {
 262                         flags |= WSC_FLAGS_LF;
 263                         send_len -= 2;
 264                 }
 265         }
 266         plen = 2 + send_len;
 267         if (flags & WSC_FLAGS_LF)
 268                 plen += 2;
 269         resp = eap_msg_alloc(EAP_VENDOR_WFA, EAP_VENDOR_TYPE_WSC, plen,
 270                              EAP_CODE_RESPONSE, id);
 271         if (resp == NULL)
 272                 return NULL;
 273
 274         wpabuf_put_u8(resp, data->out_op_code); /* Op-Code */
 275         wpabuf_put_u8(resp, flags); /* Flags */
 276         if (flags & WSC_FLAGS_LF)
 277                 wpabuf_put_be16(resp, wpabuf_len(data->out_buf));
 278
 279         wpabuf_put_data(resp, wpabuf_head_u8(data->out_buf) + data->out_used,
 280                         send_len);
 281         data->out_used += send_len;
 282
 283         ret->methodState = METHOD_MAY_CONT;
 284         ret->decision = DECISION_FAIL;
 285
 286         if (data->out_used == wpabuf_len(data->out_buf)) {
 287                 wpa_printf(MSG_DEBUG, "EAP-WSC: Sending out %lu bytes "
 288                            "(message sent completely)",
 289                            (unsigned long) send_len);
 290                 wpabuf_free(data->out_buf);
 291                 data->out_buf = NULL;
 292                 data->out_used = 0;
 293                 if ((data->state == FAIL && data->out_op_code == WSC_ACK) ||
 294                     data->out_op_code == WSC_NACK ||
 295                     data->out_op_code == WSC_Done) {
 296                         eap_wsc_state(data, FAIL);
 297                         ret->methodState = METHOD_DONE;
 298                 } else
 299                         eap_wsc_state(data, MESG);
 300         } else {
 301                 wpa_printf(MSG_DEBUG, "EAP-WSC: Sending out %lu bytes "
 302                            "(%lu more to send)", (unsigned long) send_len,
 303                            (unsigned long) wpabuf_len(data->out_buf) -
 304                            data->out_used);
 305                 eap_wsc_state(data, WAIT_FRAG_ACK);
 306         }
 307
 308         return resp;
 309 }
 310
 311
 312 static int eap_wsc_process_cont(struct eap_wsc_data *data,
 313                                 const u8 *buf, size_t len, u8 op_code)
 314 {
 315         /* Process continuation of a pending message */
 316         if (op_code != data->in_op_code) {
 317                 wpa_printf(MSG_DEBUG, "EAP-WSC: Unexpected Op-Code %d in "
 318                            "fragment (expected %d)",
 319                            op_code, data->in_op_code);
 320                 return -1;
 321         }
 322
 323         if (len > wpabuf_tailroom(data->in_buf)) {
 324                 wpa_printf(MSG_DEBUG, "EAP-WSC: Fragment overflow");
 325                 eap_wsc_state(data, FAIL);
 326                 return -1;
 327         }
 328
 329         wpabuf_put_data(data->in_buf, buf, len);
 330         wpa_printf(MSG_DEBUG, "EAP-WSC: Received %lu bytes, waiting "
 331                    "for %lu bytes more", (unsigned long) len,
 332                    (unsigned long) wpabuf_tailroom(data->in_buf));
 333
 334         return 0;
 335 }
 336
 337
 338 static struct wpabuf * eap_wsc_process_fragment(struct eap_wsc_data *data,
 339                                                 struct eap_method_ret *ret,
 340                                                 u8 id, u8 flags, u8 op_code,
 341                                                 u16 message_length,
 342                                                 const u8 *buf, size_t len)
 343 {
 344         /* Process a fragment that is not the last one of the message */
 345         if (data->in_buf == NULL && !(flags & WSC_FLAGS_LF)) {
 346                 wpa_printf(MSG_DEBUG, "EAP-WSC: No Message Length field in a "
 347                            "fragmented packet");
 348                 ret->ignore = TRUE;
 349                 return NULL;
 350         }
 351
 352         if (data->in_buf == NULL) {
 353                 /* First fragment of the message */
 354                 data->in_buf = wpabuf_alloc(message_length);
 355                 if (data->in_buf == NULL) {
 356                         wpa_printf(MSG_DEBUG, "EAP-WSC: No memory for "
 357                                    "message");
 358                         ret->ignore = TRUE;
 359                         return NULL;
 360                 }
 361                 data->in_op_code = op_code;
 362                 wpabuf_put_data(data->in_buf, buf, len);
 363                 wpa_printf(MSG_DEBUG, "EAP-WSC: Received %lu bytes in first "
 364                            "fragment, waiting for %lu bytes more",
 365                            (unsigned long) len,
 366                            (unsigned long) wpabuf_tailroom(data->in_buf));
 367         }
 368
 369         return eap_wsc_build_frag_ack(id, EAP_CODE_RESPONSE);
 370 }
 371
 372
 373 static struct wpabuf * eap_wsc_process(struct eap_sm *sm, void *priv,
 374                                        struct eap_method_ret *ret,
 375                                        const struct wpabuf *reqData)
 376 {
 377         struct eap_wsc_data *data = priv;
 378         const u8 *start, *pos, *end;
 379         size_t len;
 380         u8 op_code, flags, id;
 381         u16 message_length = 0;
 382         enum wps_process_res res;
 383         struct wpabuf tmpbuf;
 384
 385         pos = eap_hdr_validate(EAP_VENDOR_WFA, EAP_VENDOR_TYPE_WSC, reqData,
 386                                &len);
 387         if (pos == NULL || len < 2) {
 388                 ret->ignore = TRUE;
 389                 return NULL;
 390         }
 391
 392         id = eap_get_id(reqData);
 393
 394         start = pos;
 395         end = start + len;
 396
 397         op_code = *pos++;
 398         flags = *pos++;
 399         if (flags & WSC_FLAGS_LF) {
 400                 if (end - pos < 2) {
 401                         wpa_printf(MSG_DEBUG, "EAP-WSC: Message underflow");
 402                         ret->ignore = TRUE;
 403                         return NULL;
 404                 }
 405                 message_length = WPA_GET_BE16(pos);
 406                 pos += 2;
 407
 408                 if (message_length < end - pos) {
 409                         wpa_printf(MSG_DEBUG, "EAP-WSC: Invalid Message "
 410                                    "Length");
 411                         ret->ignore = TRUE;
 412                         return NULL;
 413                 }
 414         }
 415
 416         wpa_printf(MSG_DEBUG, "EAP-WSC: Received packet: Op-Code %d "
 417                    "Flags 0x%x Message Length %d",
 418                    op_code, flags, message_length);
 419
 420         if (data->state == WAIT_FRAG_ACK) {
 421                 if (op_code != WSC_FRAG_ACK) {
 422                         wpa_printf(MSG_DEBUG, "EAP-WSC: Unexpected Op-Code %d "
 423                                    "in WAIT_FRAG_ACK state", op_code);
 424                         ret->ignore = TRUE;
 425                         return NULL;
 426                 }
 427                 wpa_printf(MSG_DEBUG, "EAP-WSC: Fragment acknowledged");
 428                 eap_wsc_state(data, MESG);
 429                 return eap_wsc_build_msg(data, ret, id);
 430         }
 431
 432         if (op_code != WSC_ACK && op_code != WSC_NACK && op_code != WSC_MSG &&
 433             op_code != WSC_Done && op_code != WSC_Start) {
 434                 wpa_printf(MSG_DEBUG, "EAP-WSC: Unexpected Op-Code %d",
 435                            op_code);
 436                 ret->ignore = TRUE;
 437                 return NULL;
 438         }
 439
 440         if (data->state == WAIT_START) {
 441                 if (op_code != WSC_Start) {
 442                         wpa_printf(MSG_DEBUG, "EAP-WSC: Unexpected Op-Code %d "
 443                                    "in WAIT_START state", op_code);
 444                         ret->ignore = TRUE;
 445                         return NULL;
 446                 }
 447                 wpa_printf(MSG_DEBUG, "EAP-WSC: Received start");
 448                 eap_wsc_state(data, MESG);
 449                 /* Start message has empty payload, skip processing */
 450                 goto send_msg;
 451         } else if (op_code == WSC_Start) {
 452                 wpa_printf(MSG_DEBUG, "EAP-WSC: Unexpected Op-Code %d",
 453                            op_code);
 454                 ret->ignore = TRUE;
 455                 return NULL;
 456         }
 457
 458         if (data->in_buf &&
 459             eap_wsc_process_cont(data, pos, end - pos, op_code) < 0) {
 460                 ret->ignore = TRUE;
 461                 return NULL;
 462         }
 463
 464         if (flags & WSC_FLAGS_MF) {
 465                 return eap_wsc_process_fragment(data, ret, id, flags, op_code,
 466                                                 message_length, pos,
 467                                                 end - pos);
 468         }
 469
 470         if (data->in_buf == NULL) {
 471                 /* Wrap unfragmented messages as wpabuf without extra copy */
 472                 wpabuf_set(&tmpbuf, pos, end - pos);
 473                 data->in_buf = &tmpbuf;
 474         }
 475
 476         res = wps_process_msg(data->wps, op_code, data->in_buf);
 477         switch (res) {
 478         case WPS_DONE:
 479                 wpa_printf(MSG_DEBUG, "EAP-WSC: WPS processing completed "
 480                            "successfully - wait for EAP failure");
 481                 eap_wsc_state(data, FAIL);
 482                 break;
 483         case WPS_CONTINUE:
 484                 eap_wsc_state(data, MESG);
 485                 break;
 486         case WPS_FAILURE:
 487         case WPS_PENDING:
 488                 wpa_printf(MSG_DEBUG, "EAP-WSC: WPS processing failed");
 489                 eap_wsc_state(data, FAIL);
 490                 break;
 491         }
 492
 493         if (data->in_buf != &tmpbuf)
 494                 wpabuf_free(data->in_buf);
 495         data->in_buf = NULL;
 496
 497 send_msg:
 498         if (data->out_buf == NULL) {
 499                 data->out_buf = wps_get_msg(data->wps, &data->out_op_code);
 500                 if (data->out_buf == NULL) {
 501                         wpa_printf(MSG_DEBUG, "EAP-WSC: Failed to receive "
 502                                    "message from WPS");
 503                         return NULL;
 504                 }
 505                 data->out_used = 0;
 506         }
 507
 508         eap_wsc_state(data, MESG);
 509         return eap_wsc_build_msg(data, ret, id);
 510 }
 511
 512
 513 int eap_peer_wsc_register(void)
 514 {
 515         struct eap_method *eap;
 516         int ret;
 517
 518         eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
 519                                     EAP_VENDOR_WFA, EAP_VENDOR_TYPE_WSC,
 520                                     "WSC");
 521         if (eap == NULL)
 522                 return -1;
 523
 524         eap->init = eap_wsc_init;
 525         eap->deinit = eap_wsc_deinit;
 526         eap->process = eap_wsc_process;
 527
 528         ret = eap_peer_method_register(eap);
 529         if (ret)
 530                 eap_peer_method_free(eap);
 531         return ret;
 532 }