wpa_supplicant/ibss_rsn.c

   1 /*
   2  * wpa_supplicant - IBSS RSN
   3  * Copyright (c) 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 "l2_packet/l2_packet.h"
  13 #include "rsn_supp/wpa.h"
  14 #include "rsn_supp/wpa_ie.h"
  15 #include "ap/wpa_auth.h"
  16 #include "wpa_supplicant_i.h"
  17 #include "driver_i.h"
  18 #include "ibss_rsn.h"
  19
  20
  21 static struct ibss_rsn_peer * ibss_rsn_get_peer(struct ibss_rsn *ibss_rsn,
  22                                                 const u8 *addr)
  23 {
  24         struct ibss_rsn_peer *peer;
  25
  26         for (peer = ibss_rsn->peers; peer; peer = peer->next)
  27                 if (os_memcmp(addr, peer->addr, ETH_ALEN) == 0)
  28                         break;
  29         return peer;
  30 }
  31
  32
  33 static void ibss_rsn_free(struct ibss_rsn_peer *peer)
  34 {
  35         wpa_auth_sta_deinit(peer->auth);
  36         wpa_sm_deinit(peer->supp);
  37         os_free(peer);
  38 }
  39
  40
  41 static void supp_set_state(void *ctx, enum wpa_states state)
  42 {
  43         struct ibss_rsn_peer *peer = ctx;
  44         peer->supp_state = state;
  45 }
  46
  47
  48 static enum wpa_states supp_get_state(void *ctx)
  49 {
  50         struct ibss_rsn_peer *peer = ctx;
  51         return peer->supp_state;
  52 }
  53
  54
  55 static int supp_ether_send(void *ctx, const u8 *dest, u16 proto, const u8 *buf,
  56                            size_t len)
  57 {
  58         struct ibss_rsn_peer *peer = ctx;
  59         struct wpa_supplicant *wpa_s = peer->ibss_rsn->wpa_s;
  60
  61         wpa_printf(MSG_DEBUG, "SUPP: %s(dest=" MACSTR " proto=0x%04x "
  62                    "len=%lu)",
  63                    __func__, MAC2STR(dest), proto, (unsigned long) len);
  64
  65         if (wpa_s->l2)
  66                 return l2_packet_send(wpa_s->l2, dest, proto, buf, len);
  67
  68         return wpa_drv_send_eapol(wpa_s, dest, proto, buf, len);
  69 }
  70
  71
  72 static u8 * supp_alloc_eapol(void *ctx, u8 type, const void *data,
  73                              u16 data_len, size_t *msg_len, void **data_pos)
  74 {
  75         struct ieee802_1x_hdr *hdr;
  76
  77         wpa_printf(MSG_DEBUG, "SUPP: %s(type=%d data_len=%d)",
  78                    __func__, type, data_len);
  79
  80         *msg_len = sizeof(*hdr) + data_len;
  81         hdr = os_malloc(*msg_len);
  82         if (hdr == NULL)
  83                 return NULL;
  84
  85         hdr->version = 2;
  86         hdr->type = type;
  87         hdr->length = host_to_be16(data_len);
  88
  89         if (data)
  90                 os_memcpy(hdr + 1, data, data_len);
  91         else
  92                 os_memset(hdr + 1, 0, data_len);
  93
  94         if (data_pos)
  95                 *data_pos = hdr + 1;
  96
  97         return (u8 *) hdr;
  98 }
  99
 100
 101 static int supp_get_beacon_ie(void *ctx)
 102 {
 103         struct ibss_rsn_peer *peer = ctx;
 104
 105         wpa_printf(MSG_DEBUG, "SUPP: %s", __func__);
 106         /* TODO: get correct RSN IE */
 107         return wpa_sm_set_ap_rsn_ie(peer->supp,
 108                                     (u8 *) "\x30\x14\x01\x00"
 109                                     "\x00\x0f\xac\x04"
 110                                     "\x01\x00\x00\x0f\xac\x04"
 111                                     "\x01\x00\x00\x0f\xac\x02"
 112                                     "\x00\x00", 22);
 113 }
 114
 115
 116 static int supp_set_key(void *ctx, enum wpa_alg alg,
 117                         const u8 *addr, int key_idx, int set_tx,
 118                         const u8 *seq, size_t seq_len,
 119                         const u8 *key, size_t key_len)
 120 {
 121         struct ibss_rsn_peer *peer = ctx;
 122
 123         wpa_printf(MSG_DEBUG, "SUPP: %s(alg=%d addr=" MACSTR " key_idx=%d "
 124                    "set_tx=%d)",
 125                    __func__, alg, MAC2STR(addr), key_idx, set_tx);
 126         wpa_hexdump(MSG_DEBUG, "SUPP: set_key - seq", seq, seq_len);
 127         wpa_hexdump_key(MSG_DEBUG, "SUPP: set_key - key", key, key_len);
 128
 129         if (key_idx == 0) {
 130                 /*
 131                  * In IBSS RSN, the pairwise key from the 4-way handshake
 132                  * initiated by the peer with highest MAC address is used.
 133                  */
 134                 if (os_memcmp(peer->ibss_rsn->wpa_s->own_addr, peer->addr,
 135                               ETH_ALEN) > 0) {
 136                         wpa_printf(MSG_DEBUG, "SUPP: Do not use this PTK");
 137                         return 0;
 138                 }
 139         }
 140
 141         if (is_broadcast_ether_addr(addr))
 142                 addr = peer->addr;
 143         return wpa_drv_set_key(peer->ibss_rsn->wpa_s, alg, addr, key_idx,
 144                                set_tx, seq, seq_len, key, key_len);
 145 }
 146
 147
 148 static void * supp_get_network_ctx(void *ctx)
 149 {
 150         struct ibss_rsn_peer *peer = ctx;
 151         return wpa_supplicant_get_ssid(peer->ibss_rsn->wpa_s);
 152 }
 153
 154
 155 static int supp_mlme_setprotection(void *ctx, const u8 *addr,
 156                                    int protection_type, int key_type)
 157 {
 158         wpa_printf(MSG_DEBUG, "SUPP: %s(addr=" MACSTR " protection_type=%d "
 159                    "key_type=%d)",
 160                    __func__, MAC2STR(addr), protection_type, key_type);
 161         return 0;
 162 }
 163
 164
 165 static void supp_cancel_auth_timeout(void *ctx)
 166 {
 167         wpa_printf(MSG_DEBUG, "SUPP: %s", __func__);
 168 }
 169
 170
 171 static void supp_deauthenticate(void * ctx, int reason_code)
 172 {
 173         wpa_printf(MSG_DEBUG, "SUPP: %s (TODO)", __func__);
 174 }
 175
 176
 177 static int ibss_rsn_supp_init(struct ibss_rsn_peer *peer, const u8 *own_addr,
 178                               const u8 *psk)
 179 {
 180         struct wpa_sm_ctx *ctx = os_zalloc(sizeof(*ctx));
 181         if (ctx == NULL)
 182                 return -1;
 183
 184         ctx->ctx = peer;
 185         ctx->msg_ctx = peer->ibss_rsn->wpa_s;
 186         ctx->set_state = supp_set_state;
 187         ctx->get_state = supp_get_state;
 188         ctx->ether_send = supp_ether_send;
 189         ctx->get_beacon_ie = supp_get_beacon_ie;
 190         ctx->alloc_eapol = supp_alloc_eapol;
 191         ctx->set_key = supp_set_key;
 192         ctx->get_network_ctx = supp_get_network_ctx;
 193         ctx->mlme_setprotection = supp_mlme_setprotection;
 194         ctx->cancel_auth_timeout = supp_cancel_auth_timeout;
 195         ctx->deauthenticate = supp_deauthenticate;
 196         peer->supp = wpa_sm_init(ctx);
 197         if (peer->supp == NULL) {
 198                 wpa_printf(MSG_DEBUG, "SUPP: wpa_sm_init() failed");
 199                 return -1;
 200         }
 201
 202         wpa_sm_set_own_addr(peer->supp, own_addr);
 203         wpa_sm_set_param(peer->supp, WPA_PARAM_RSN_ENABLED, 1);
 204         wpa_sm_set_param(peer->supp, WPA_PARAM_PROTO, WPA_PROTO_RSN);
 205         wpa_sm_set_param(peer->supp, WPA_PARAM_PAIRWISE, WPA_CIPHER_CCMP);
 206         wpa_sm_set_param(peer->supp, WPA_PARAM_GROUP, WPA_CIPHER_CCMP);
 207         wpa_sm_set_param(peer->supp, WPA_PARAM_KEY_MGMT, WPA_KEY_MGMT_PSK);
 208         wpa_sm_set_pmk(peer->supp, psk, PMK_LEN);
 209
 210         peer->supp_ie_len = sizeof(peer->supp_ie);
 211         if (wpa_sm_set_assoc_wpa_ie_default(peer->supp, peer->supp_ie,
 212                                             &peer->supp_ie_len) < 0) {
 213                 wpa_printf(MSG_DEBUG, "SUPP: wpa_sm_set_assoc_wpa_ie_default()"
 214                            " failed");
 215                 return -1;
 216         }
 217
 218         wpa_sm_notify_assoc(peer->supp, peer->addr);
 219
 220         return 0;
 221 }
 222
 223
 224 static void auth_logger(void *ctx, const u8 *addr, logger_level level,
 225                         const char *txt)
 226 {
 227         if (addr)
 228                 wpa_printf(MSG_DEBUG, "AUTH: " MACSTR " - %s",
 229                            MAC2STR(addr), txt);
 230         else
 231                 wpa_printf(MSG_DEBUG, "AUTH: %s", txt);
 232 }
 233
 234
 235 static const u8 * auth_get_psk(void *ctx, const u8 *addr, const u8 *prev_psk)
 236 {
 237         struct ibss_rsn *ibss_rsn = ctx;
 238         wpa_printf(MSG_DEBUG, "AUTH: %s (addr=" MACSTR " prev_psk=%p)",
 239                    __func__, MAC2STR(addr), prev_psk);
 240         if (prev_psk)
 241                 return NULL;
 242         return ibss_rsn->psk;
 243 }
 244
 245
 246 static int auth_send_eapol(void *ctx, const u8 *addr, const u8 *data,
 247                            size_t data_len, int encrypt)
 248 {
 249         struct ibss_rsn *ibss_rsn = ctx;
 250         struct wpa_supplicant *wpa_s = ibss_rsn->wpa_s;
 251
 252         wpa_printf(MSG_DEBUG, "AUTH: %s(addr=" MACSTR " data_len=%lu "
 253                    "encrypt=%d)",
 254                    __func__, MAC2STR(addr), (unsigned long) data_len, encrypt);
 255
 256         if (wpa_s->l2)
 257                 return l2_packet_send(wpa_s->l2, addr, ETH_P_EAPOL, data,
 258                                       data_len);
 259
 260         return wpa_drv_send_eapol(wpa_s, addr, ETH_P_EAPOL, data, data_len);
 261 }
 262
 263
 264 static int auth_set_key(void *ctx, int vlan_id, enum wpa_alg alg,
 265                         const u8 *addr, int idx, u8 *key, size_t key_len)
 266 {
 267         struct ibss_rsn *ibss_rsn = ctx;
 268         u8 seq[6];
 269
 270         os_memset(seq, 0, sizeof(seq));
 271
 272         if (addr) {
 273                 wpa_printf(MSG_DEBUG, "AUTH: %s(alg=%d addr=" MACSTR
 274                            " key_idx=%d)",
 275                            __func__, alg, MAC2STR(addr), idx);
 276         } else {
 277                 wpa_printf(MSG_DEBUG, "AUTH: %s(alg=%d key_idx=%d)",
 278                            __func__, alg, idx);
 279         }
 280         wpa_hexdump_key(MSG_DEBUG, "AUTH: set_key - key", key, key_len);
 281
 282         if (idx == 0) {
 283                 /*
 284                  * In IBSS RSN, the pairwise key from the 4-way handshake
 285                  * initiated by the peer with highest MAC address is used.
 286                  */
 287                 if (addr == NULL ||
 288                     os_memcmp(ibss_rsn->wpa_s->own_addr, addr, ETH_ALEN) < 0) {
 289                         wpa_printf(MSG_DEBUG, "AUTH: Do not use this PTK");
 290                         return 0;
 291                 }
 292         }
 293
 294         return wpa_drv_set_key(ibss_rsn->wpa_s, alg, addr, idx,
 295                                1, seq, 6, key, key_len);
 296 }
 297
 298
 299 static int auth_for_each_sta(void *ctx, int (*cb)(struct wpa_state_machine *sm,
 300                                                   void *ctx),
 301                              void *cb_ctx)
 302 {
 303         struct ibss_rsn *ibss_rsn = ctx;
 304         struct ibss_rsn_peer *peer;
 305
 306         wpa_printf(MSG_DEBUG, "AUTH: for_each_sta");
 307
 308         for (peer = ibss_rsn->peers; peer; peer = peer->next) {
 309                 if (peer->auth && cb(peer->auth, cb_ctx))
 310                         return 1;
 311         }
 312
 313         return 0;
 314 }
 315
 316
 317 static int ibss_rsn_auth_init_group(struct ibss_rsn *ibss_rsn,
 318                                     const u8 *own_addr)
 319 {
 320         struct wpa_auth_config conf;
 321         struct wpa_auth_callbacks cb;
 322
 323         wpa_printf(MSG_DEBUG, "AUTH: Initializing group state machine");
 324
 325         os_memset(&conf, 0, sizeof(conf));
 326         conf.wpa = 2;
 327         conf.wpa_key_mgmt = WPA_KEY_MGMT_PSK;
 328         conf.wpa_pairwise = WPA_CIPHER_CCMP;
 329         conf.rsn_pairwise = WPA_CIPHER_CCMP;
 330         conf.wpa_group = WPA_CIPHER_CCMP;
 331         conf.eapol_version = 2;
 332         conf.wpa_group_rekey = 600;
 333
 334         os_memset(&cb, 0, sizeof(cb));
 335         cb.ctx = ibss_rsn;
 336         cb.logger = auth_logger;
 337         cb.send_eapol = auth_send_eapol;
 338         cb.get_psk = auth_get_psk;
 339         cb.set_key = auth_set_key;
 340         cb.for_each_sta = auth_for_each_sta;
 341
 342         ibss_rsn->auth_group = wpa_init(own_addr, &conf, &cb);
 343         if (ibss_rsn->auth_group == NULL) {
 344                 wpa_printf(MSG_DEBUG, "AUTH: wpa_init() failed");
 345                 return -1;
 346         }
 347
 348         wpa_init_keys(ibss_rsn->auth_group);
 349
 350         return 0;
 351 }
 352
 353
 354 static int ibss_rsn_auth_init(struct ibss_rsn *ibss_rsn,
 355                               struct ibss_rsn_peer *peer)
 356 {
 357         peer->auth = wpa_auth_sta_init(ibss_rsn->auth_group, peer->addr);
 358         if (peer->auth == NULL) {
 359                 wpa_printf(MSG_DEBUG, "AUTH: wpa_auth_sta_init() failed");
 360                 return -1;
 361         }
 362
 363         /* TODO: get peer RSN IE with Probe Request */
 364         if (wpa_validate_wpa_ie(ibss_rsn->auth_group, peer->auth,
 365                                 (u8 *) "\x30\x14\x01\x00"
 366                                 "\x00\x0f\xac\x04"
 367                                 "\x01\x00\x00\x0f\xac\x04"
 368                                 "\x01\x00\x00\x0f\xac\x02"
 369                                 "\x00\x00", 22, NULL, 0) !=
 370             WPA_IE_OK) {
 371                 wpa_printf(MSG_DEBUG, "AUTH: wpa_validate_wpa_ie() failed");
 372                 return -1;
 373         }
 374
 375         if (wpa_auth_sm_event(peer->auth, WPA_ASSOC))
 376                 return -1;
 377
 378         if (wpa_auth_sta_associated(ibss_rsn->auth_group, peer->auth))
 379                 return -1;
 380
 381         return 0;
 382 }
 383
 384
 385 int ibss_rsn_start(struct ibss_rsn *ibss_rsn, const u8 *addr)
 386 {
 387         struct ibss_rsn_peer *peer;
 388
 389         if (ibss_rsn == NULL)
 390                 return -1;
 391
 392         if (ibss_rsn_get_peer(ibss_rsn, addr)) {
 393                 wpa_printf(MSG_DEBUG, "RSN: IBSS Authenticator and Supplicant "
 394                            "for peer " MACSTR " already running",
 395                            MAC2STR(addr));
 396                 return 0;
 397         }
 398
 399         wpa_printf(MSG_DEBUG, "RSN: Starting IBSS Authenticator and "
 400                    "Supplicant for peer " MACSTR, MAC2STR(addr));
 401
 402         peer = os_zalloc(sizeof(*peer));
 403         if (peer == NULL)
 404                 return -1;
 405
 406         peer->ibss_rsn = ibss_rsn;
 407         os_memcpy(peer->addr, addr, ETH_ALEN);
 408
 409         if (ibss_rsn_supp_init(peer, ibss_rsn->wpa_s->own_addr, ibss_rsn->psk)
 410             < 0) {
 411                 ibss_rsn_free(peer);
 412                 return -1;
 413         }
 414
 415         if (ibss_rsn_auth_init(ibss_rsn, peer) < 0) {
 416                 ibss_rsn_free(peer);
 417                 return -1;
 418         }
 419
 420         peer->next = ibss_rsn->peers;
 421         ibss_rsn->peers = peer;
 422
 423         return 0;
 424 }
 425
 426
 427 void ibss_rsn_stop(struct ibss_rsn *ibss_rsn, const u8 *peermac)
 428 {
 429         struct ibss_rsn_peer *peer, *prev;
 430
 431         if (ibss_rsn == NULL)
 432                 return;
 433
 434         if (peermac == NULL) {
 435                 /* remove all peers */
 436                 wpa_printf(MSG_DEBUG, "%s: Remove all peers", __func__);
 437                 peer = ibss_rsn->peers;
 438                 while (peer) {
 439                         prev = peer;
 440                         peer = peer->next;
 441                         ibss_rsn_free(prev);
 442                         ibss_rsn->peers = peer;
 443                 }
 444         } else {
 445                 /* remove specific peer */
 446                 wpa_printf(MSG_DEBUG, "%s: Remove specific peer " MACSTR,
 447                            __func__, MAC2STR(peermac));
 448
 449                 for (prev = NULL, peer = ibss_rsn->peers; peer != NULL;
 450                      prev = peer, peer = peer->next) {
 451                         if (os_memcmp(peermac, peer->addr, ETH_ALEN) == 0) {
 452                                 if (prev == NULL)
 453                                         ibss_rsn->peers = peer->next;
 454                                 else
 455                                         prev->next = peer->next;
 456                                 ibss_rsn_free(peer);
 457                                 wpa_printf(MSG_DEBUG, "%s: Successfully "
 458                                            "removed a specific peer",
 459                                            __func__);
 460                                 break;
 461                         }
 462                 }
 463         }
 464 }
 465
 466
 467 struct ibss_rsn * ibss_rsn_init(struct wpa_supplicant *wpa_s)
 468 {
 469         struct ibss_rsn *ibss_rsn;
 470
 471         ibss_rsn = os_zalloc(sizeof(*ibss_rsn));
 472         if (ibss_rsn == NULL)
 473                 return NULL;
 474         ibss_rsn->wpa_s = wpa_s;
 475
 476         if (ibss_rsn_auth_init_group(ibss_rsn, wpa_s->own_addr) < 0) {
 477                 ibss_rsn_deinit(ibss_rsn);
 478                 return NULL;
 479         }
 480
 481         return ibss_rsn;
 482 }
 483
 484
 485 void ibss_rsn_deinit(struct ibss_rsn *ibss_rsn)
 486 {
 487         struct ibss_rsn_peer *peer, *prev;
 488
 489         if (ibss_rsn == NULL)
 490                 return;
 491
 492         peer = ibss_rsn->peers;
 493         while (peer) {
 494                 prev = peer;
 495                 peer = peer->next;
 496                 ibss_rsn_free(prev);
 497         }
 498
 499         wpa_deinit(ibss_rsn->auth_group);
 500         os_free(ibss_rsn);
 501
 502 }
 503
 504
 505 static int ibss_rsn_eapol_dst_supp(const u8 *buf, size_t len)
 506 {
 507         const struct ieee802_1x_hdr *hdr;
 508         const struct wpa_eapol_key *key;
 509         u16 key_info;
 510         size_t plen;
 511
 512         /* TODO: Support other EAPOL packets than just EAPOL-Key */
 513
 514         if (len < sizeof(*hdr) + sizeof(*key))
 515                 return -1;
 516
 517         hdr = (const struct ieee802_1x_hdr *) buf;
 518         key = (const struct wpa_eapol_key *) (hdr + 1);
 519         plen = be_to_host16(hdr->length);
 520
 521         if (hdr->version < EAPOL_VERSION) {
 522                 /* TODO: backwards compatibility */
 523         }
 524         if (hdr->type != IEEE802_1X_TYPE_EAPOL_KEY) {
 525                 wpa_printf(MSG_DEBUG, "RSN: EAPOL frame (type %u) discarded, "
 526                         "not a Key frame", hdr->type);
 527                 return -1;
 528         }
 529         if (plen > len - sizeof(*hdr) || plen < sizeof(*key)) {
 530                 wpa_printf(MSG_DEBUG, "RSN: EAPOL frame payload size %lu "
 531                            "invalid (frame size %lu)",
 532                            (unsigned long) plen, (unsigned long) len);
 533                 return -1;
 534         }
 535
 536         if (key->type != EAPOL_KEY_TYPE_RSN) {
 537                 wpa_printf(MSG_DEBUG, "RSN: EAPOL-Key type (%d) unknown, "
 538                            "discarded", key->type);
 539                 return -1;
 540         }
 541
 542         key_info = WPA_GET_BE16(key->key_info);
 543
 544         return !!(key_info & WPA_KEY_INFO_ACK);
 545 }
 546
 547
 548 static int ibss_rsn_process_rx_eapol(struct ibss_rsn *ibss_rsn,
 549                                      struct ibss_rsn_peer *peer,
 550                                      const u8 *buf, size_t len)
 551 {
 552         int supp;
 553         u8 *tmp;
 554
 555         supp = ibss_rsn_eapol_dst_supp(buf, len);
 556         if (supp < 0)
 557                 return -1;
 558
 559         tmp = os_malloc(len);
 560         if (tmp == NULL)
 561                 return -1;
 562         os_memcpy(tmp, buf, len);
 563         if (supp) {
 564                 wpa_printf(MSG_DEBUG, "RSN: IBSS RX EAPOL for Supplicant");
 565                 wpa_sm_rx_eapol(peer->supp, peer->addr, tmp, len);
 566         } else {
 567                 wpa_printf(MSG_DEBUG, "RSN: IBSS RX EAPOL for Authenticator");
 568                 wpa_receive(ibss_rsn->auth_group, peer->auth, tmp, len);
 569         }
 570         os_free(tmp);
 571
 572         return 1;
 573 }
 574
 575
 576 int ibss_rsn_rx_eapol(struct ibss_rsn *ibss_rsn, const u8 *src_addr,
 577                       const u8 *buf, size_t len)
 578 {
 579         struct ibss_rsn_peer *peer;
 580
 581         if (ibss_rsn == NULL)
 582                 return -1;
 583
 584         peer = ibss_rsn_get_peer(ibss_rsn, src_addr);
 585         if (peer)
 586                 return ibss_rsn_process_rx_eapol(ibss_rsn, peer, buf, len);
 587
 588         if (ibss_rsn_eapol_dst_supp(buf, len) > 0) {
 589                 /*
 590                  * Create new IBSS peer based on an EAPOL message from the peer
 591                  * Authenticator.
 592                  */
 593                 if (ibss_rsn_start(ibss_rsn, src_addr) < 0)
 594                         return -1;
 595                 return ibss_rsn_process_rx_eapol(ibss_rsn, ibss_rsn->peers,
 596                                                  buf, len);
 597         }
 598
 599         return 0;
 600 }
 601
 602
 603 void ibss_rsn_set_psk(struct ibss_rsn *ibss_rsn, const u8 *psk)
 604 {
 605         if (ibss_rsn == NULL)
 606                 return;
 607         os_memcpy(ibss_rsn->psk, psk, PMK_LEN);
 608 }