/*
* hostapd - PeerKey for Direct Link Setup (DLS)
* Copyright (c) 2006-2009, Jouni Malinen <j@w1.fi>
*
* This software may be distributed under the terms of the BSD license.
* See README for more details.
*/
#include "utils/includes.h"
#include "utils/common.h"
#include "utils/eloop.h"
#include "crypto/sha1.h"
#include "crypto/sha256.h"
#include "crypto/random.h"
#include "wpa_auth.h"
#include "wpa_auth_i.h"
#include "wpa_auth_ie.h"
#ifdef CONFIG_PEERKEY
static void wpa_stsl_step(void *eloop_ctx, void *timeout_ctx)
{
#if 0
struct wpa_authenticator *wpa_auth = eloop_ctx;
struct wpa_stsl_negotiation *neg = timeout_ctx;
#endif
/* TODO: ? */
}
struct wpa_stsl_search {
const u8 *addr;
struct wpa_state_machine *sm;
};
static int wpa_stsl_select_sta(struct wpa_state_machine *sm, void *ctx)
{
struct wpa_stsl_search *search = ctx;
if (os_memcmp(search->addr, sm->addr, ETH_ALEN) == 0) {
search->sm = sm;
return 1;
}
return 0;
}
static void wpa_smk_send_error(struct wpa_authenticator *wpa_auth,
struct wpa_state_machine *sm, const u8 *peer,
u16 mui, u16 error_type)
{
u8 kde[2 + RSN_SELECTOR_LEN + ETH_ALEN +
2 + RSN_SELECTOR_LEN + sizeof(struct rsn_error_kde)];
u8 *pos;
struct rsn_error_kde error;
wpa_auth_logger(wpa_auth, sm->addr, LOGGER_DEBUG,
"Sending SMK Error");
pos = kde;
if (peer) {
pos = wpa_add_kde(pos, RSN_KEY_DATA_MAC_ADDR, peer, ETH_ALEN,
NULL, 0);
}
error.mui = host_to_be16(mui);
error.error_type = host_to_be16(error_type);
pos = wpa_add_kde(pos, RSN_KEY_DATA_ERROR,
(u8 *) &error, sizeof(error), NULL, 0);
__wpa_send_eapol(wpa_auth, sm,
WPA_KEY_INFO_SECURE | WPA_KEY_INFO_MIC |
WPA_KEY_INFO_SMK_MESSAGE | WPA_KEY_INFO_ERROR,
NULL, NULL, kde, pos - kde, 0, 0, 0);
}
void wpa_smk_m1(struct wpa_authenticator *wpa_auth,
struct wpa_state_machine *sm, struct wpa_eapol_key *key)
{
struct wpa_eapol_ie_parse kde;
struct wpa_stsl_search search;
u8 *buf, *pos;
size_t buf_len;
if (wpa_parse_kde_ies((const u8 *) (key + 1),
WPA_GET_BE16(key->key_data_length), &kde) < 0) {
wpa_printf(MSG_INFO, "RSN: Failed to parse KDEs in SMK M1");
return;
}
if (kde.rsn_ie == NULL || kde.mac_addr == NULL ||
kde.mac_addr_len < ETH_ALEN) {
wpa_printf(MSG_INFO, "RSN: No RSN IE or MAC address KDE in "
"SMK M1");
return;
}
/* Initiator = sm->addr; Peer = kde.mac_addr */
search.addr = kde.mac_addr;
search.sm = NULL;
if (wpa_auth_for_each_sta(wpa_auth, wpa_stsl_select_sta, &search) ==
0 || search.sm == NULL) {
wpa_printf(MSG_DEBUG, "RSN: SMK handshake with " MACSTR
" aborted - STA not associated anymore",
MAC2STR(kde.mac_addr));
wpa_smk_send_error(wpa_auth, sm, kde.mac_addr, STK_MUI_SMK,
STK_ERR_STA_NR);
/* FIX: wpa_stsl_remove(wpa_auth, neg); */
return;
}
buf_len = kde.rsn_ie_len + 2 + RSN_SELECTOR_LEN + ETH_ALEN;
buf = os_malloc(buf_len);
if (buf == NULL)
return;
/* Initiator RSN IE */
os_memcpy(buf, kde.rsn_ie, kde.rsn_ie_len);
pos = buf + kde.rsn_ie_len;
/* Initiator MAC Address */
pos = wpa_add_kde(pos, RSN_KEY_DATA_MAC_ADDR, sm->addr, ETH_ALEN,
NULL, 0);
/* SMK M2:
* EAPOL-Key(S=1, M=1, A=1, I=0, K=0, SM=1, KeyRSC=0, Nonce=INonce,
* MIC=MIC, DataKDs=(RSNIE_I, MAC_I KDE)
*/
wpa_auth_logger(wpa_auth, search.sm->addr, LOGGER_DEBUG,
"Sending SMK M2");
__wpa_send_eapol(wpa_auth, search.sm,
WPA_KEY_INFO_SECURE | WPA_KEY_INFO_MIC |
WPA_KEY_INFO_ACK | WPA_KEY_INFO_SMK_MESSAGE,
NULL, key->key_nonce, buf, pos - buf, 0, 0, 0);
os_free(buf);
}
static void wpa_send_smk_m4(struct wpa_authenticator *wpa_auth,
struct wpa_state_machine *sm,
struct wpa_eapol_key *key,
struct wpa_eapol_ie_parse *kde,
const u8 *smk)
{
u8 *buf, *pos;
size_t buf_len;
u32 lifetime;
/* SMK M4:
* EAPOL-Key(S=1, M=1, A=0, I=1, K=0, SM=1, KeyRSC=0, Nonce=PNonce,
* MIC=MIC, DataKDs=(MAC_I KDE, INonce KDE, SMK KDE,
* Lifetime KDE)
*/
buf_len = 2 + RSN_SELECTOR_LEN + ETH_ALEN +
2 + RSN_SELECTOR_LEN + WPA_NONCE_LEN +
2 + RSN_SELECTOR_LEN + PMK_LEN + WPA_NONCE_LEN +
2 + RSN_SELECTOR_LEN + sizeof(lifetime);
pos = buf = os_malloc(buf_len);
if (buf == NULL)
return;
/* Initiator MAC Address */
pos = wpa_add_kde(pos, RSN_KEY_DATA_MAC_ADDR, kde->mac_addr, ETH_ALEN,
NULL, 0);
/* Initiator Nonce */
pos = wpa_add_kde(pos, RSN_KEY_DATA_NONCE, kde->nonce, WPA_NONCE_LEN,
NULL, 0);
/* SMK with PNonce */
pos = wpa_add_kde(pos, RSN_KEY_DATA_SMK, smk, PMK_LEN,
key->key_nonce, WPA_NONCE_LEN);
/* Lifetime */
lifetime = htonl(43200); /* dot11RSNAConfigSMKLifetime */
pos = wpa_add_kde(pos, RSN_KEY_DATA_LIFETIME,
(u8 *) &lifetime, sizeof(lifetime), NULL, 0);
wpa_auth_logger(sm->wpa_auth, sm->addr, LOGGER_DEBUG,
"Sending SMK M4");
__wpa_send_eapol(wpa_auth, sm,
WPA_KEY_INFO_SECURE | WPA_KEY_INFO_MIC |
WPA_KEY_INFO_INSTALL | WPA_KEY_INFO_SMK_MESSAGE,
NULL, key->key_nonce, buf, pos - buf, 0, 1, 0);
os_free(buf);
}
static void wpa_send_smk_m5(struct wpa_authenticator *wpa_auth,
struct wpa_state_machine *sm,
struct wpa_eapol_key *key,
struct wpa_eapol_ie_parse *kde,
const u8 *smk, const u8 *peer)
{
u8 *buf, *pos;
size_t buf_len;
u32 lifetime;
/* SMK M5:
* EAPOL-Key(S=1, M=1, A=0, I=0, K=0, SM=1, KeyRSC=0, Nonce=INonce,
* MIC=MIC, DataKDs=(RSNIE_P, MAC_P KDE, PNonce, SMK KDE,
* Lifetime KDE))
*/
buf_len = kde->rsn_ie_len +
2 + RSN_SELECTOR_LEN + ETH_ALEN +
2 + RSN_SELECTOR_LEN + WPA_NONCE_LEN +
2 + RSN_SELECTOR_LEN + PMK_LEN + WPA_NONCE_LEN +
2 + RSN_SELECTOR_LEN + sizeof(lifetime);
pos = buf = os_malloc(buf_len);
if (buf == NULL)
return;
/* Peer RSN IE */
os_memcpy(buf, kde->rsn_ie, kde->rsn_ie_len);
pos = buf + kde->rsn_ie_len;
/* Peer MAC Address */
pos = wpa_add_kde(pos, RSN_KEY_DATA_MAC_ADDR, peer, ETH_ALEN, NULL, 0);
/* PNonce */
pos = wpa_add_kde(pos, RSN_KEY_DATA_NONCE, key->key_nonce,
WPA_NONCE_LEN, NULL, 0);
/* SMK and INonce */
pos = wpa_add_kde(pos, RSN_KEY_DATA_SMK, smk, PMK_LEN,
kde->nonce, WPA_NONCE_LEN);
/* Lifetime */
lifetime = htonl(43200); /* dot11RSNAConfigSMKLifetime */
pos = wpa_add_kde(pos, RSN_KEY_DATA_LIFETIME,
(u8 *) &lifetime, sizeof(lifetime), NULL, 0);
wpa_auth_logger(sm->wpa_auth, sm->addr, LOGGER_DEBUG,
"Sending SMK M5");
__wpa_send_eapol(wpa_auth, sm,
WPA_KEY_INFO_SECURE | WPA_KEY_INFO_MIC |
WPA_KEY_INFO_SMK_MESSAGE,
NULL, kde->nonce, buf, pos - buf, 0, 1, 0);
os_free(buf);
}
void wpa_smk_m3(struct wpa_authenticator *wpa_auth,
struct wpa_state_machine *sm, struct wpa_eapol_key *key)
{
struct wpa_eapol_ie_parse kde;
struct wpa_stsl_search search;
u8 smk[32], buf[ETH_ALEN + 8 + 2 * WPA_NONCE_LEN], *pos;
if (wpa_parse_kde_ies((const u8 *) (key + 1),
WPA_GET_BE16(key->key_data_length), &kde) < 0) {
wpa_printf(MSG_INFO, "RSN: Failed to parse KDEs in SMK M3");
return;
}
if (kde.rsn_ie == NULL ||
kde.mac_addr == NULL || kde.mac_addr_len < ETH_ALEN ||
kde.nonce == NULL || kde.nonce_len < WPA_NONCE_LEN) {
wpa_printf(MSG_INFO, "RSN: No RSN IE, MAC address KDE, or "
"Nonce KDE in SMK M3");
return;
}
/* Peer = sm->addr; Initiator = kde.mac_addr;
* Peer Nonce = key->key_nonce; Initiator Nonce = kde.nonce */
search.addr = kde.mac_addr;
search.sm = NULL;
if (wpa_auth_for_each_sta(wpa_auth, wpa_stsl_select_sta, &search) ==
0 || search.sm == NULL) {
wpa_printf(MSG_DEBUG, "RSN: SMK handshake with " MACSTR
" aborted - STA not associated anymore",
MAC2STR(kde.mac_addr));
wpa_smk_send_error(wpa_auth, sm, kde.mac_addr, STK_MUI_SMK,
STK_ERR_STA_NR);
/* FIX: wpa_stsl_remove(wpa_auth, neg); */
return;
}
if (random_get_bytes(smk, PMK_LEN)) {
wpa_printf(MSG_DEBUG, "RSN: Failed to generate SMK");
return;
}
/* SMK = PRF-256(Random number, "SMK Derivation",
* AA || Time || INonce || PNonce)
*/
os_memcpy(buf, wpa_auth->addr, ETH_ALEN);
pos = buf + ETH_ALEN;
wpa_get_ntp_timestamp(pos);
pos += 8;
os_memcpy(pos, kde.nonce, WPA_NONCE_LEN);
pos += WPA_NONCE_LEN;
os_memcpy(pos, key->key_nonce, WPA_NONCE_LEN);
#ifdef CONFIG_IEEE80211W
sha256_prf(smk, PMK_LEN, "SMK Derivation", buf, sizeof(buf),
smk, PMK_LEN);
#else /* CONFIG_IEEE80211W */
sha1_prf(smk, PMK_LEN, "SMK Derivation", buf, sizeof(buf),
smk, PMK_LEN);
#endif /* CONFIG_IEEE80211W */
wpa_hexdump_key(MSG_DEBUG, "RSN: SMK", smk, PMK_LEN);
wpa_send_smk_m4(wpa_auth, sm, key, &kde, smk);
wpa_send_smk_m5(wpa_auth, search.sm, key, &kde, smk, sm->addr);
/* Authenticator does not need SMK anymore and it is required to forget
* it. */
os_memset(smk, 0, sizeof(*smk));
}
void wpa_smk_error(struct wpa_authenticator *wpa_auth,
struct wpa_state_machine *sm, struct wpa_eapol_key *key)
{
struct wpa_eapol_ie_parse kde;
struct wpa_stsl_search search;
struct rsn_error_kde error;
u16 mui, error_type;
if (wpa_parse_kde_ies((const u8 *) (key + 1),
WPA_GET_BE16(key->key_data_length), &kde) < 0) {
wpa_printf(MSG_INFO, "RSN: Failed to parse KDEs in SMK Error");
return;
}
if (kde.mac_addr == NULL || kde.mac_addr_len < ETH_ALEN ||
kde.error == NULL || kde.error_len < sizeof(error)) {
wpa_printf(MSG_INFO, "RSN: No MAC address or Error KDE in "
"SMK Error");
return;
}
search.addr = kde.mac_addr;
search.sm = NULL;
if (wpa_auth_for_each_sta(wpa_auth, wpa_stsl_select_sta, &search) ==
0 || search.sm == NULL) {
wpa_printf(MSG_DEBUG, "RSN: Peer STA " MACSTR " not "
"associated for SMK Error message from " MACSTR,
MAC2STR(kde.mac_addr), MAC2STR(sm->addr));
return;
}
os_memcpy(&error, kde.error, sizeof(error));
mui = be_to_host16(error.mui);
error_type = be_to_host16(error.error_type);
wpa_auth_vlogger(wpa_auth, sm->addr, LOGGER_INFO,
"STA reported SMK Error: Peer " MACSTR
" MUI %d Error Type %d",
MAC2STR(kde.mac_addr), mui, error_type);
wpa_smk_send_error(wpa_auth, search.sm, sm->addr, mui, error_type);
}
int wpa_stsl_remove(struct wpa_authenticator *wpa_auth,
struct wpa_stsl_negotiation *neg)
{
struct wpa_stsl_negotiation *pos, *prev;
if (wpa_auth == NULL)
return -1;
pos = wpa_auth->stsl_negotiations;
prev = NULL;
while (pos) {
if (pos == neg) {
if (prev)
prev->next = pos->next;
else
wpa_auth->stsl_negotiations = pos->next;
eloop_cancel_timeout(wpa_stsl_step, wpa_auth, pos);
os_free(pos);
return 0;
}
prev = pos;
pos = pos->next;
}
return -1;
}
#endif /* CONFIG_PEERKEY */