hostap/wpa_supplicant/ibss_rsn.c
Jouni Malinen a416fb47eb IBSS RSN: Explicitly check addr != NULL before passing it to memcmp
idx == 0 should be enough to make sure that the addr is set, but
verify that this is indeed the case to avoid any potential issues if
auth_set_key() gets called incorrectly.
2010-01-10 21:53:17 +02:00

510 lines
12 KiB
C

/*
* wpa_supplicant - IBSS RSN
* Copyright (c) 2009, Jouni Malinen <j@w1.fi>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* Alternatively, this software may be distributed under the terms of BSD
* license.
*
* See README and COPYING for more details.
*/
#include "includes.h"
#include "common.h"
#include "l2_packet/l2_packet.h"
#include "rsn_supp/wpa.h"
#include "rsn_supp/wpa_ie.h"
#include "ap/wpa_auth.h"
#include "wpa_supplicant_i.h"
#include "driver_i.h"
#include "ibss_rsn.h"
static void ibss_rsn_free(struct ibss_rsn_peer *peer)
{
wpa_auth_sta_deinit(peer->auth);
wpa_sm_deinit(peer->supp);
os_free(peer);
}
static void supp_set_state(void *ctx, enum wpa_states state)
{
struct ibss_rsn_peer *peer = ctx;
peer->supp_state = state;
}
static int supp_ether_send(void *ctx, const u8 *dest, u16 proto, const u8 *buf,
size_t len)
{
struct ibss_rsn_peer *peer = ctx;
struct wpa_supplicant *wpa_s = peer->ibss_rsn->wpa_s;
wpa_printf(MSG_DEBUG, "SUPP: %s(dest=" MACSTR " proto=0x%04x "
"len=%lu)",
__func__, MAC2STR(dest), proto, (unsigned long) len);
if (wpa_s->l2)
return l2_packet_send(wpa_s->l2, dest, proto, buf, len);
return wpa_drv_send_eapol(wpa_s, dest, proto, buf, len);
}
static u8 * supp_alloc_eapol(void *ctx, u8 type, const void *data,
u16 data_len, size_t *msg_len, void **data_pos)
{
struct ieee802_1x_hdr *hdr;
wpa_printf(MSG_DEBUG, "SUPP: %s(type=%d data_len=%d)",
__func__, type, data_len);
*msg_len = sizeof(*hdr) + data_len;
hdr = os_malloc(*msg_len);
if (hdr == NULL)
return NULL;
hdr->version = 2;
hdr->type = type;
hdr->length = host_to_be16(data_len);
if (data)
os_memcpy(hdr + 1, data, data_len);
else
os_memset(hdr + 1, 0, data_len);
if (data_pos)
*data_pos = hdr + 1;
return (u8 *) hdr;
}
static int supp_get_beacon_ie(void *ctx)
{
struct ibss_rsn_peer *peer = ctx;
wpa_printf(MSG_DEBUG, "SUPP: %s", __func__);
/* TODO: get correct RSN IE */
return wpa_sm_set_ap_rsn_ie(peer->supp,
(u8 *) "\x30\x14\x01\x00"
"\x00\x0f\xac\x04"
"\x01\x00\x00\x0f\xac\x04"
"\x01\x00\x00\x0f\xac\x02"
"\x00\x00", 22);
}
static int supp_set_key(void *ctx, enum wpa_alg alg,
const u8 *addr, int key_idx, int set_tx,
const u8 *seq, size_t seq_len,
const u8 *key, size_t key_len)
{
struct ibss_rsn_peer *peer = ctx;
wpa_printf(MSG_DEBUG, "SUPP: %s(alg=%d addr=" MACSTR " key_idx=%d "
"set_tx=%d)",
__func__, alg, MAC2STR(addr), key_idx, set_tx);
wpa_hexdump(MSG_DEBUG, "SUPP: set_key - seq", seq, seq_len);
wpa_hexdump_key(MSG_DEBUG, "SUPP: set_key - key", key, key_len);
if (key_idx == 0) {
/*
* In IBSS RSN, the pairwise key from the 4-way handshake
* initiated by the peer with highest MAC address is used.
*/
if (os_memcmp(peer->ibss_rsn->wpa_s->own_addr, peer->addr,
ETH_ALEN) > 0) {
wpa_printf(MSG_DEBUG, "SUPP: Do not use this PTK");
return 0;
}
}
return wpa_drv_set_key(peer->ibss_rsn->wpa_s, alg, addr, key_idx,
set_tx, seq, seq_len, key, key_len);
}
static void * supp_get_network_ctx(void *ctx)
{
struct ibss_rsn_peer *peer = ctx;
return wpa_supplicant_get_ssid(peer->ibss_rsn->wpa_s);
}
static int supp_mlme_setprotection(void *ctx, const u8 *addr,
int protection_type, int key_type)
{
wpa_printf(MSG_DEBUG, "SUPP: %s(addr=" MACSTR " protection_type=%d "
"key_type=%d)",
__func__, MAC2STR(addr), protection_type, key_type);
return 0;
}
static void supp_cancel_auth_timeout(void *ctx)
{
wpa_printf(MSG_DEBUG, "SUPP: %s", __func__);
}
int ibss_rsn_supp_init(struct ibss_rsn_peer *peer, const u8 *own_addr,
const u8 *psk)
{
struct wpa_sm_ctx *ctx = os_zalloc(sizeof(*ctx));
if (ctx == NULL)
return -1;
ctx->ctx = peer;
ctx->msg_ctx = peer->ibss_rsn->wpa_s;
ctx->set_state = supp_set_state;
ctx->ether_send = supp_ether_send;
ctx->get_beacon_ie = supp_get_beacon_ie;
ctx->alloc_eapol = supp_alloc_eapol;
ctx->set_key = supp_set_key;
ctx->get_network_ctx = supp_get_network_ctx;
ctx->mlme_setprotection = supp_mlme_setprotection;
ctx->cancel_auth_timeout = supp_cancel_auth_timeout;
peer->supp = wpa_sm_init(ctx);
if (peer->supp == NULL) {
wpa_printf(MSG_DEBUG, "SUPP: wpa_sm_init() failed");
return -1;
}
wpa_sm_set_own_addr(peer->supp, own_addr);
wpa_sm_set_param(peer->supp, WPA_PARAM_RSN_ENABLED, 1);
wpa_sm_set_param(peer->supp, WPA_PARAM_PROTO, WPA_PROTO_RSN);
wpa_sm_set_param(peer->supp, WPA_PARAM_PAIRWISE, WPA_CIPHER_CCMP);
wpa_sm_set_param(peer->supp, WPA_PARAM_GROUP, WPA_CIPHER_CCMP);
wpa_sm_set_param(peer->supp, WPA_PARAM_KEY_MGMT, WPA_KEY_MGMT_PSK);
wpa_sm_set_pmk(peer->supp, psk, PMK_LEN);
peer->supp_ie_len = sizeof(peer->supp_ie);
if (wpa_sm_set_assoc_wpa_ie_default(peer->supp, peer->supp_ie,
&peer->supp_ie_len) < 0) {
wpa_printf(MSG_DEBUG, "SUPP: wpa_sm_set_assoc_wpa_ie_default()"
" failed");
return -1;
}
wpa_sm_notify_assoc(peer->supp, peer->addr);
return 0;
}
static void auth_logger(void *ctx, const u8 *addr, logger_level level,
const char *txt)
{
if (addr)
wpa_printf(MSG_DEBUG, "AUTH: " MACSTR " - %s",
MAC2STR(addr), txt);
else
wpa_printf(MSG_DEBUG, "AUTH: %s", txt);
}
static const u8 * auth_get_psk(void *ctx, const u8 *addr, const u8 *prev_psk)
{
struct ibss_rsn *ibss_rsn = ctx;
wpa_printf(MSG_DEBUG, "AUTH: %s (addr=" MACSTR " prev_psk=%p)",
__func__, MAC2STR(addr), prev_psk);
if (prev_psk)
return NULL;
return ibss_rsn->psk;
}
static int auth_send_eapol(void *ctx, const u8 *addr, const u8 *data,
size_t data_len, int encrypt)
{
struct ibss_rsn *ibss_rsn = ctx;
struct wpa_supplicant *wpa_s = ibss_rsn->wpa_s;
wpa_printf(MSG_DEBUG, "AUTH: %s(addr=" MACSTR " data_len=%lu "
"encrypt=%d)",
__func__, MAC2STR(addr), (unsigned long) data_len, encrypt);
if (wpa_s->l2)
return l2_packet_send(wpa_s->l2, addr, ETH_P_EAPOL, data,
data_len);
return wpa_drv_send_eapol(wpa_s, addr, ETH_P_EAPOL, data, data_len);
}
static int auth_set_key(void *ctx, int vlan_id, enum wpa_alg alg,
const u8 *addr, int idx, u8 *key, size_t key_len)
{
struct ibss_rsn *ibss_rsn = ctx;
u8 seq[6];
os_memset(seq, 0, sizeof(seq));
if (addr) {
wpa_printf(MSG_DEBUG, "AUTH: %s(alg=%d addr=" MACSTR
" key_idx=%d)",
__func__, alg, MAC2STR(addr), idx);
} else {
wpa_printf(MSG_DEBUG, "AUTH: %s(alg=%d key_idx=%d)",
__func__, alg, idx);
}
wpa_hexdump_key(MSG_DEBUG, "AUTH: set_key - key", key, key_len);
if (idx == 0) {
/*
* In IBSS RSN, the pairwise key from the 4-way handshake
* initiated by the peer with highest MAC address is used.
*/
if (addr == NULL ||
os_memcmp(ibss_rsn->wpa_s->own_addr, addr, ETH_ALEN) < 0) {
wpa_printf(MSG_DEBUG, "AUTH: Do not use this PTK");
return 0;
}
}
return wpa_drv_set_key(ibss_rsn->wpa_s, alg, addr, idx,
1, seq, 6, key, key_len);
}
static int ibss_rsn_auth_init_group(struct ibss_rsn *ibss_rsn,
const u8 *own_addr)
{
struct wpa_auth_config conf;
struct wpa_auth_callbacks cb;
wpa_printf(MSG_DEBUG, "AUTH: Initializing group state machine");
os_memset(&conf, 0, sizeof(conf));
conf.wpa = 2;
conf.wpa_key_mgmt = WPA_KEY_MGMT_PSK;
conf.wpa_pairwise = WPA_CIPHER_CCMP;
conf.rsn_pairwise = WPA_CIPHER_CCMP;
conf.wpa_group = WPA_CIPHER_CCMP;
conf.eapol_version = 2;
os_memset(&cb, 0, sizeof(cb));
cb.ctx = ibss_rsn;
cb.logger = auth_logger;
cb.send_eapol = auth_send_eapol;
cb.get_psk = auth_get_psk;
cb.set_key = auth_set_key;
ibss_rsn->auth_group = wpa_init(own_addr, &conf, &cb);
if (ibss_rsn->auth_group == NULL) {
wpa_printf(MSG_DEBUG, "AUTH: wpa_init() failed");
return -1;
}
return 0;
}
static int ibss_rsn_auth_init(struct ibss_rsn *ibss_rsn,
struct ibss_rsn_peer *peer)
{
peer->auth = wpa_auth_sta_init(ibss_rsn->auth_group, peer->addr);
if (peer->auth == NULL) {
wpa_printf(MSG_DEBUG, "AUTH: wpa_auth_sta_init() failed");
return -1;
}
/* TODO: get peer RSN IE with Probe Request */
if (wpa_validate_wpa_ie(ibss_rsn->auth_group, peer->auth,
(u8 *) "\x30\x14\x01\x00"
"\x00\x0f\xac\x04"
"\x01\x00\x00\x0f\xac\x04"
"\x01\x00\x00\x0f\xac\x02"
"\x00\x00", 22, NULL, 0) !=
WPA_IE_OK) {
wpa_printf(MSG_DEBUG, "AUTH: wpa_validate_wpa_ie() failed");
return -1;
}
if (wpa_auth_sm_event(peer->auth, WPA_ASSOC))
return -1;
if (wpa_auth_sta_associated(ibss_rsn->auth_group, peer->auth))
return -1;
return 0;
}
int ibss_rsn_start(struct ibss_rsn *ibss_rsn, const u8 *addr)
{
struct ibss_rsn_peer *peer;
wpa_printf(MSG_DEBUG, "RSN: Starting IBSS Authenticator and "
"Supplicant for peer " MACSTR, MAC2STR(addr));
peer = os_zalloc(sizeof(*peer));
if (peer == NULL)
return -1;
peer->ibss_rsn = ibss_rsn;
os_memcpy(peer->addr, addr, ETH_ALEN);
if (ibss_rsn_supp_init(peer, ibss_rsn->wpa_s->own_addr, ibss_rsn->psk)
< 0) {
ibss_rsn_free(peer);
return -1;
}
if (ibss_rsn_auth_init(ibss_rsn, peer) < 0) {
ibss_rsn_free(peer);
return -1;
}
peer->next = ibss_rsn->peers;
ibss_rsn->peers = peer;
return 0;
}
struct ibss_rsn * ibss_rsn_init(struct wpa_supplicant *wpa_s)
{
struct ibss_rsn *ibss_rsn;
ibss_rsn = os_zalloc(sizeof(*ibss_rsn));
if (ibss_rsn == NULL)
return NULL;
ibss_rsn->wpa_s = wpa_s;
if (ibss_rsn_auth_init_group(ibss_rsn, wpa_s->own_addr) < 0) {
ibss_rsn_deinit(ibss_rsn);
return NULL;
}
return ibss_rsn;
}
void ibss_rsn_deinit(struct ibss_rsn *ibss_rsn)
{
struct ibss_rsn_peer *peer, *prev;
if (ibss_rsn == NULL)
return;
peer = ibss_rsn->peers;
while (peer) {
prev = peer;
peer = peer->next;
ibss_rsn_free(prev);
}
wpa_deinit(ibss_rsn->auth_group);
os_free(ibss_rsn);
}
static int ibss_rsn_eapol_dst_supp(const u8 *buf, size_t len)
{
const struct ieee802_1x_hdr *hdr;
const struct wpa_eapol_key *key;
u16 key_info;
size_t plen;
/* TODO: Support other EAPOL packets than just EAPOL-Key */
if (len < sizeof(*hdr) + sizeof(*key))
return -1;
hdr = (const struct ieee802_1x_hdr *) buf;
key = (const struct wpa_eapol_key *) (hdr + 1);
plen = be_to_host16(hdr->length);
if (hdr->version < EAPOL_VERSION) {
/* TODO: backwards compatibility */
}
if (hdr->type != IEEE802_1X_TYPE_EAPOL_KEY) {
wpa_printf(MSG_DEBUG, "RSN: EAPOL frame (type %u) discarded, "
"not a Key frame", hdr->type);
return -1;
}
if (plen > len - sizeof(*hdr) || plen < sizeof(*key)) {
wpa_printf(MSG_DEBUG, "RSN: EAPOL frame payload size %lu "
"invalid (frame size %lu)",
(unsigned long) plen, (unsigned long) len);
return -1;
}
if (key->type != EAPOL_KEY_TYPE_RSN) {
wpa_printf(MSG_DEBUG, "RSN: EAPOL-Key type (%d) unknown, "
"discarded", key->type);
return -1;
}
key_info = WPA_GET_BE16(key->key_info);
return !!(key_info & WPA_KEY_INFO_ACK);
}
static int ibss_rsn_process_rx_eapol(struct ibss_rsn *ibss_rsn,
struct ibss_rsn_peer *peer,
const u8 *buf, size_t len)
{
int supp;
u8 *tmp;
supp = ibss_rsn_eapol_dst_supp(buf, len);
if (supp < 0)
return -1;
tmp = os_malloc(len);
if (tmp == NULL)
return -1;
os_memcpy(tmp, buf, len);
if (supp) {
wpa_printf(MSG_DEBUG, "RSN: IBSS RX EAPOL for Supplicant");
wpa_sm_rx_eapol(peer->supp, peer->addr, tmp, len);
} else {
wpa_printf(MSG_DEBUG, "RSN: IBSS RX EAPOL for Authenticator");
wpa_receive(ibss_rsn->auth_group, peer->auth, tmp, len);
}
os_free(tmp);
return 1;
}
int ibss_rsn_rx_eapol(struct ibss_rsn *ibss_rsn, const u8 *src_addr,
const u8 *buf, size_t len)
{
struct ibss_rsn_peer *peer;
for (peer = ibss_rsn->peers; peer; peer = peer->next) {
if (os_memcmp(src_addr, peer->addr, ETH_ALEN) == 0)
return ibss_rsn_process_rx_eapol(ibss_rsn, peer,
buf, len);
}
if (ibss_rsn_eapol_dst_supp(buf, len) > 0) {
/*
* Create new IBSS peer based on an EAPOL message from the peer
* Authenticator.
*/
if (ibss_rsn_start(ibss_rsn, src_addr) < 0)
return -1;
return ibss_rsn_process_rx_eapol(ibss_rsn, ibss_rsn->peers,
buf, len);
}
return 0;
}
void ibss_rsn_set_psk(struct ibss_rsn *ibss_rsn, const u8 *psk)
{
os_memcpy(ibss_rsn->psk, psk, PMK_LEN);
}