ibss_rsn.c
Go to the documentation of this file.
00001 /*
00002  * wpa_supplicant - IBSS RSN
00003  * Copyright (c) 2009, Jouni Malinen <j@w1.fi>
00004  *
00005  * This program is free software; you can redistribute it and/or modify
00006  * it under the terms of the GNU General Public License version 2 as
00007  * published by the Free Software Foundation.
00008  *
00009  * Alternatively, this software may be distributed under the terms of BSD
00010  * license.
00011  *
00012  * See README and COPYING for more details.
00013  */
00014 
00015 #include "includes.h"
00016 
00017 #include "common.h"
00018 #include "l2_packet/l2_packet.h"
00019 #include "rsn_supp/wpa.h"
00020 #include "rsn_supp/wpa_ie.h"
00021 #include "ap/wpa_auth.h"
00022 #include "wpa_supplicant_i.h"
00023 #include "driver_i.h"
00024 #include "ibss_rsn.h"
00025 
00026 
00027 static void ibss_rsn_free(struct ibss_rsn_peer *peer)
00028 {
00029         wpa_auth_sta_deinit(peer->auth);
00030         wpa_sm_deinit(peer->supp);
00031         os_free(peer);
00032 }
00033 
00034 
00035 static void supp_set_state(void *ctx, enum wpa_states state)
00036 {
00037         struct ibss_rsn_peer *peer = ctx;
00038         peer->supp_state = state;
00039 }
00040 
00041 
00042 static int supp_ether_send(void *ctx, const u8 *dest, u16 proto, const u8 *buf,
00043                            size_t len)
00044 {
00045         struct ibss_rsn_peer *peer = ctx;
00046         struct wpa_supplicant *wpa_s = peer->ibss_rsn->wpa_s;
00047 
00048         wpa_printf(MSG_DEBUG, "SUPP: %s(dest=" MACSTR " proto=0x%04x "
00049                    "len=%lu)",
00050                    __func__, MAC2STR(dest), proto, (unsigned long) len);
00051 
00052         if (wpa_s->l2)
00053                 return l2_packet_send(wpa_s->l2, dest, proto, buf, len);
00054 
00055         return wpa_drv_send_eapol(wpa_s, dest, proto, buf, len);
00056 }
00057 
00058 
00059 static u8 * supp_alloc_eapol(void *ctx, u8 type, const void *data,
00060                              u16 data_len, size_t *msg_len, void **data_pos)
00061 {
00062         struct ieee802_1x_hdr *hdr;
00063 
00064         wpa_printf(MSG_DEBUG, "SUPP: %s(type=%d data_len=%d)",
00065                    __func__, type, data_len);
00066 
00067         *msg_len = sizeof(*hdr) + data_len;
00068         hdr = os_malloc(*msg_len);
00069         if (hdr == NULL)
00070                 return NULL;
00071 
00072         hdr->version = 2;
00073         hdr->type = type;
00074         hdr->length = host_to_be16(data_len);
00075 
00076         if (data)
00077                 os_memcpy(hdr + 1, data, data_len);
00078         else
00079                 os_memset(hdr + 1, 0, data_len);
00080 
00081         if (data_pos)
00082                 *data_pos = hdr + 1;
00083 
00084         return (u8 *) hdr;
00085 }
00086 
00087 
00088 static int supp_get_beacon_ie(void *ctx)
00089 {
00090         struct ibss_rsn_peer *peer = ctx;
00091 
00092         wpa_printf(MSG_DEBUG, "SUPP: %s", __func__);
00093         /* TODO: get correct RSN IE */
00094         return wpa_sm_set_ap_rsn_ie(peer->supp,
00095                                     (u8 *) "\x30\x14\x01\x00"
00096                                     "\x00\x0f\xac\x04"
00097                                     "\x01\x00\x00\x0f\xac\x04"
00098                                     "\x01\x00\x00\x0f\xac\x02"
00099                                     "\x00\x00", 22);
00100 }
00101 
00102 
00103 static int supp_set_key(void *ctx, enum wpa_alg alg,
00104                         const u8 *addr, int key_idx, int set_tx,
00105                         const u8 *seq, size_t seq_len,
00106                         const u8 *key, size_t key_len)
00107 {
00108         struct ibss_rsn_peer *peer = ctx;
00109 
00110         wpa_printf(MSG_DEBUG, "SUPP: %s(alg=%d addr=" MACSTR " key_idx=%d "
00111                    "set_tx=%d)",
00112                    __func__, alg, MAC2STR(addr), key_idx, set_tx);
00113         wpa_hexdump(MSG_DEBUG, "SUPP: set_key - seq", seq, seq_len);
00114         wpa_hexdump_key(MSG_DEBUG, "SUPP: set_key - key", key, key_len);
00115 
00116         if (key_idx == 0) {
00117                 /*
00118                  * In IBSS RSN, the pairwise key from the 4-way handshake
00119                  * initiated by the peer with highest MAC address is used.
00120                  */
00121                 if (os_memcmp(peer->ibss_rsn->wpa_s->own_addr, peer->addr,
00122                               ETH_ALEN) > 0) {
00123                         wpa_printf(MSG_DEBUG, "SUPP: Do not use this PTK");
00124                         return 0;
00125                 }
00126         }
00127 
00128         return wpa_drv_set_key(peer->ibss_rsn->wpa_s, alg, addr, key_idx,
00129                                set_tx, seq, seq_len, key, key_len);
00130 }
00131 
00132 
00133 static void * supp_get_network_ctx(void *ctx)
00134 {
00135         struct ibss_rsn_peer *peer = ctx;
00136         return wpa_supplicant_get_ssid(peer->ibss_rsn->wpa_s);
00137 }
00138 
00139 
00140 static int supp_mlme_setprotection(void *ctx, const u8 *addr,
00141                                    int protection_type, int key_type)
00142 {
00143         wpa_printf(MSG_DEBUG, "SUPP: %s(addr=" MACSTR " protection_type=%d "
00144                    "key_type=%d)",
00145                    __func__, MAC2STR(addr), protection_type, key_type);
00146         return 0;
00147 }
00148 
00149 
00150 static void supp_cancel_auth_timeout(void *ctx)
00151 {
00152         wpa_printf(MSG_DEBUG, "SUPP: %s", __func__);
00153 }
00154 
00155 
00156 int ibss_rsn_supp_init(struct ibss_rsn_peer *peer, const u8 *own_addr,
00157                        const u8 *psk)
00158 {
00159         struct wpa_sm_ctx *ctx = os_zalloc(sizeof(*ctx));
00160         if (ctx == NULL)
00161                 return -1;
00162 
00163         ctx->ctx = peer;
00164         ctx->msg_ctx = peer->ibss_rsn->wpa_s;
00165         ctx->set_state = supp_set_state;
00166         ctx->ether_send = supp_ether_send;
00167         ctx->get_beacon_ie = supp_get_beacon_ie;
00168         ctx->alloc_eapol = supp_alloc_eapol;
00169         ctx->set_key = supp_set_key;
00170         ctx->get_network_ctx = supp_get_network_ctx;
00171         ctx->mlme_setprotection = supp_mlme_setprotection;
00172         ctx->cancel_auth_timeout = supp_cancel_auth_timeout;
00173         peer->supp = wpa_sm_init(ctx);
00174         if (peer->supp == NULL) {
00175                 wpa_printf(MSG_DEBUG, "SUPP: wpa_sm_init() failed");
00176                 return -1;
00177         }
00178 
00179         wpa_sm_set_own_addr(peer->supp, own_addr);
00180         wpa_sm_set_param(peer->supp, WPA_PARAM_RSN_ENABLED, 1);
00181         wpa_sm_set_param(peer->supp, WPA_PARAM_PROTO, WPA_PROTO_RSN);
00182         wpa_sm_set_param(peer->supp, WPA_PARAM_PAIRWISE, WPA_CIPHER_CCMP);
00183         wpa_sm_set_param(peer->supp, WPA_PARAM_GROUP, WPA_CIPHER_CCMP);
00184         wpa_sm_set_param(peer->supp, WPA_PARAM_KEY_MGMT, WPA_KEY_MGMT_PSK);
00185         wpa_sm_set_pmk(peer->supp, psk, PMK_LEN);
00186 
00187         peer->supp_ie_len = sizeof(peer->supp_ie);
00188         if (wpa_sm_set_assoc_wpa_ie_default(peer->supp, peer->supp_ie,
00189                                             &peer->supp_ie_len) < 0) {
00190                 wpa_printf(MSG_DEBUG, "SUPP: wpa_sm_set_assoc_wpa_ie_default()"
00191                            " failed");
00192                 return -1;
00193         }
00194 
00195         wpa_sm_notify_assoc(peer->supp, peer->addr);
00196 
00197         return 0;
00198 }
00199 
00200 
00201 static void auth_logger(void *ctx, const u8 *addr, logger_level level,
00202                         const char *txt)
00203 {
00204         if (addr)
00205                 wpa_printf(MSG_DEBUG, "AUTH: " MACSTR " - %s",
00206                            MAC2STR(addr), txt);
00207         else
00208                 wpa_printf(MSG_DEBUG, "AUTH: %s", txt);
00209 }
00210 
00211 
00212 static const u8 * auth_get_psk(void *ctx, const u8 *addr, const u8 *prev_psk)
00213 {
00214         struct ibss_rsn *ibss_rsn = ctx;
00215         wpa_printf(MSG_DEBUG, "AUTH: %s (addr=" MACSTR " prev_psk=%p)",
00216                    __func__, MAC2STR(addr), prev_psk);
00217         if (prev_psk)
00218                 return NULL;
00219         return ibss_rsn->psk;
00220 }
00221 
00222 
00223 static int auth_send_eapol(void *ctx, const u8 *addr, const u8 *data,
00224                            size_t data_len, int encrypt)
00225 {
00226         struct ibss_rsn *ibss_rsn = ctx;
00227         struct wpa_supplicant *wpa_s = ibss_rsn->wpa_s;
00228 
00229         wpa_printf(MSG_DEBUG, "AUTH: %s(addr=" MACSTR " data_len=%lu "
00230                    "encrypt=%d)",
00231                    __func__, MAC2STR(addr), (unsigned long) data_len, encrypt);
00232 
00233         if (wpa_s->l2)
00234                 return l2_packet_send(wpa_s->l2, addr, ETH_P_EAPOL, data,
00235                                       data_len);
00236 
00237         return wpa_drv_send_eapol(wpa_s, addr, ETH_P_EAPOL, data, data_len);
00238 }
00239 
00240 
00241 static int auth_set_key(void *ctx, int vlan_id, enum wpa_alg alg,
00242                         const u8 *addr, int idx, u8 *key, size_t key_len)
00243 {
00244         struct ibss_rsn *ibss_rsn = ctx;
00245         u8 seq[6];
00246 
00247         os_memset(seq, 0, sizeof(seq));
00248 
00249         if (addr) {
00250                 wpa_printf(MSG_DEBUG, "AUTH: %s(alg=%d addr=" MACSTR
00251                            " key_idx=%d)",
00252                            __func__, alg, MAC2STR(addr), idx);
00253         } else {
00254                 wpa_printf(MSG_DEBUG, "AUTH: %s(alg=%d key_idx=%d)",
00255                            __func__, alg, idx);
00256         }
00257         wpa_hexdump_key(MSG_DEBUG, "AUTH: set_key - key", key, key_len);
00258 
00259         if (idx == 0) {
00260                 /*
00261                  * In IBSS RSN, the pairwise key from the 4-way handshake
00262                  * initiated by the peer with highest MAC address is used.
00263                  */
00264                 if (addr == NULL ||
00265                     os_memcmp(ibss_rsn->wpa_s->own_addr, addr, ETH_ALEN) < 0) {
00266                         wpa_printf(MSG_DEBUG, "AUTH: Do not use this PTK");
00267                         return 0;
00268                 }
00269         }
00270 
00271         return wpa_drv_set_key(ibss_rsn->wpa_s, alg, addr, idx,
00272                                1, seq, 6, key, key_len);
00273 }
00274 
00275 
00276 static int ibss_rsn_auth_init_group(struct ibss_rsn *ibss_rsn,
00277                                     const u8 *own_addr)
00278 {
00279         struct wpa_auth_config conf;
00280         struct wpa_auth_callbacks cb;
00281 
00282         wpa_printf(MSG_DEBUG, "AUTH: Initializing group state machine");
00283 
00284         os_memset(&conf, 0, sizeof(conf));
00285         conf.wpa = 2;
00286         conf.wpa_key_mgmt = WPA_KEY_MGMT_PSK;
00287         conf.wpa_pairwise = WPA_CIPHER_CCMP;
00288         conf.rsn_pairwise = WPA_CIPHER_CCMP;
00289         conf.wpa_group = WPA_CIPHER_CCMP;
00290         conf.eapol_version = 2;
00291 
00292         os_memset(&cb, 0, sizeof(cb));
00293         cb.ctx = ibss_rsn;
00294         cb.logger = auth_logger;
00295         cb.send_eapol = auth_send_eapol;
00296         cb.get_psk = auth_get_psk;
00297         cb.set_key = auth_set_key;
00298 
00299         ibss_rsn->auth_group = wpa_init(own_addr, &conf, &cb);
00300         if (ibss_rsn->auth_group == NULL) {
00301                 wpa_printf(MSG_DEBUG, "AUTH: wpa_init() failed");
00302                 return -1;
00303         }
00304 
00305         return 0;
00306 }
00307 
00308 
00309 static int ibss_rsn_auth_init(struct ibss_rsn *ibss_rsn,
00310                               struct ibss_rsn_peer *peer)
00311 {
00312         peer->auth = wpa_auth_sta_init(ibss_rsn->auth_group, peer->addr);
00313         if (peer->auth == NULL) {
00314                 wpa_printf(MSG_DEBUG, "AUTH: wpa_auth_sta_init() failed");
00315                 return -1;
00316         }
00317 
00318         /* TODO: get peer RSN IE with Probe Request */
00319         if (wpa_validate_wpa_ie(ibss_rsn->auth_group, peer->auth,
00320                                 (u8 *) "\x30\x14\x01\x00"
00321                                 "\x00\x0f\xac\x04"
00322                                 "\x01\x00\x00\x0f\xac\x04"
00323                                 "\x01\x00\x00\x0f\xac\x02"
00324                                 "\x00\x00", 22, NULL, 0) !=
00325             WPA_IE_OK) {
00326                 wpa_printf(MSG_DEBUG, "AUTH: wpa_validate_wpa_ie() failed");
00327                 return -1;
00328         }
00329 
00330         if (wpa_auth_sm_event(peer->auth, WPA_ASSOC))
00331                 return -1;
00332 
00333         if (wpa_auth_sta_associated(ibss_rsn->auth_group, peer->auth))
00334                 return -1;
00335 
00336         return 0;
00337 }
00338 
00339 
00340 int ibss_rsn_start(struct ibss_rsn *ibss_rsn, const u8 *addr)
00341 {
00342         struct ibss_rsn_peer *peer;
00343 
00344         wpa_printf(MSG_DEBUG, "RSN: Starting IBSS Authenticator and "
00345                    "Supplicant for peer " MACSTR, MAC2STR(addr));
00346 
00347         peer = os_zalloc(sizeof(*peer));
00348         if (peer == NULL)
00349                 return -1;
00350 
00351         peer->ibss_rsn = ibss_rsn;
00352         os_memcpy(peer->addr, addr, ETH_ALEN);
00353 
00354         if (ibss_rsn_supp_init(peer, ibss_rsn->wpa_s->own_addr, ibss_rsn->psk)
00355             < 0) {
00356                 ibss_rsn_free(peer);
00357                 return -1;
00358         }
00359 
00360         if (ibss_rsn_auth_init(ibss_rsn, peer) < 0) {
00361                 ibss_rsn_free(peer);
00362                 return -1;
00363         }
00364 
00365         peer->next = ibss_rsn->peers;
00366         ibss_rsn->peers = peer;
00367 
00368         return 0;
00369 }
00370 
00371 
00372 struct ibss_rsn * ibss_rsn_init(struct wpa_supplicant *wpa_s)
00373 {
00374         struct ibss_rsn *ibss_rsn;
00375 
00376         ibss_rsn = os_zalloc(sizeof(*ibss_rsn));
00377         if (ibss_rsn == NULL)
00378                 return NULL;
00379         ibss_rsn->wpa_s = wpa_s;
00380 
00381         if (ibss_rsn_auth_init_group(ibss_rsn, wpa_s->own_addr) < 0) {
00382                 ibss_rsn_deinit(ibss_rsn);
00383                 return NULL;
00384         }
00385 
00386         return ibss_rsn;
00387 }
00388 
00389 
00390 void ibss_rsn_deinit(struct ibss_rsn *ibss_rsn)
00391 {
00392         struct ibss_rsn_peer *peer, *prev;
00393 
00394         if (ibss_rsn == NULL)
00395                 return;
00396 
00397         peer = ibss_rsn->peers;
00398         while (peer) {
00399                 prev = peer;
00400                 peer = peer->next;
00401                 ibss_rsn_free(prev);
00402         }
00403 
00404         wpa_deinit(ibss_rsn->auth_group);
00405         os_free(ibss_rsn);
00406 
00407 }
00408 
00409 
00410 static int ibss_rsn_eapol_dst_supp(const u8 *buf, size_t len)
00411 {
00412         const struct ieee802_1x_hdr *hdr;
00413         const struct wpa_eapol_key *key;
00414         u16 key_info;
00415         size_t plen;
00416 
00417         /* TODO: Support other EAPOL packets than just EAPOL-Key */
00418 
00419         if (len < sizeof(*hdr) + sizeof(*key))
00420                 return -1;
00421 
00422         hdr = (const struct ieee802_1x_hdr *) buf;
00423         key = (const struct wpa_eapol_key *) (hdr + 1);
00424         plen = be_to_host16(hdr->length);
00425 
00426         if (hdr->version < EAPOL_VERSION) {
00427                 /* TODO: backwards compatibility */
00428         }
00429         if (hdr->type != IEEE802_1X_TYPE_EAPOL_KEY) {
00430                 wpa_printf(MSG_DEBUG, "RSN: EAPOL frame (type %u) discarded, "
00431                         "not a Key frame", hdr->type);
00432                 return -1;
00433         }
00434         if (plen > len - sizeof(*hdr) || plen < sizeof(*key)) {
00435                 wpa_printf(MSG_DEBUG, "RSN: EAPOL frame payload size %lu "
00436                            "invalid (frame size %lu)",
00437                            (unsigned long) plen, (unsigned long) len);
00438                 return -1;
00439         }
00440 
00441         if (key->type != EAPOL_KEY_TYPE_RSN) {
00442                 wpa_printf(MSG_DEBUG, "RSN: EAPOL-Key type (%d) unknown, "
00443                            "discarded", key->type);
00444                 return -1;
00445         }
00446 
00447         key_info = WPA_GET_BE16(key->key_info);
00448 
00449         return !!(key_info & WPA_KEY_INFO_ACK);
00450 }
00451 
00452 
00453 static int ibss_rsn_process_rx_eapol(struct ibss_rsn *ibss_rsn,
00454                                      struct ibss_rsn_peer *peer,
00455                                      const u8 *buf, size_t len)
00456 {
00457         int supp;
00458         u8 *tmp;
00459 
00460         supp = ibss_rsn_eapol_dst_supp(buf, len);
00461         if (supp < 0)
00462                 return -1;
00463 
00464         tmp = os_malloc(len);
00465         if (tmp == NULL)
00466                 return -1;
00467         os_memcpy(tmp, buf, len);
00468         if (supp) {
00469                 wpa_printf(MSG_DEBUG, "RSN: IBSS RX EAPOL for Supplicant");
00470                 wpa_sm_rx_eapol(peer->supp, peer->addr, tmp, len);
00471         } else {
00472                 wpa_printf(MSG_DEBUG, "RSN: IBSS RX EAPOL for Authenticator");
00473                 wpa_receive(ibss_rsn->auth_group, peer->auth, tmp, len);
00474         }
00475         os_free(tmp);
00476 
00477         return 1;
00478 }
00479 
00480 
00481 int ibss_rsn_rx_eapol(struct ibss_rsn *ibss_rsn, const u8 *src_addr,
00482                       const u8 *buf, size_t len)
00483 {
00484         struct ibss_rsn_peer *peer;
00485 
00486         for (peer = ibss_rsn->peers; peer; peer = peer->next) {
00487                 if (os_memcmp(src_addr, peer->addr, ETH_ALEN) == 0)
00488                         return ibss_rsn_process_rx_eapol(ibss_rsn, peer,
00489                                                          buf, len);
00490         }
00491 
00492         if (ibss_rsn_eapol_dst_supp(buf, len) > 0) {
00493                 /*
00494                  * Create new IBSS peer based on an EAPOL message from the peer
00495                  * Authenticator.
00496                  */
00497                 if (ibss_rsn_start(ibss_rsn, src_addr) < 0)
00498                         return -1;
00499                 return ibss_rsn_process_rx_eapol(ibss_rsn, ibss_rsn->peers,
00500                                                  buf, len);
00501         }
00502 
00503         return 0;
00504 }
00505 
00506 
00507 void ibss_rsn_set_psk(struct ibss_rsn *ibss_rsn, const u8 *psk)
00508 {
00509         os_memcpy(ibss_rsn->psk, psk, PMK_LEN);
00510 }


wpa_supplicant_node
Author(s): Package maintained by Blaise Gassend
autogenerated on Thu Apr 24 2014 15:33:20