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