wpa_supplicant/ibss_rsn.c

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