hostapd/src/rsn_supp/peerkey.c
Jouni Malinen 0e75b3c352 Use zero address when reporting unknown peer in SMK error
This avoids potential use of uninitialized stack memory when printing
out peer address based on SMK error message that does not include the
MAC address.
2010-01-10 19:00:25 +02:00

1184 lines
34 KiB
C

/*
* WPA Supplicant - PeerKey for Direct Link Setup (DLS)
* Copyright (c) 2006-2008, 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"
#ifdef CONFIG_PEERKEY
#include "common.h"
#include "eloop.h"
#include "crypto/sha1.h"
#include "crypto/sha256.h"
#include "common/ieee802_11_defs.h"
#include "wpa.h"
#include "wpa_i.h"
#include "wpa_ie.h"
#include "peerkey.h"
static u8 * wpa_add_ie(u8 *pos, const u8 *ie, size_t ie_len)
{
os_memcpy(pos, ie, ie_len);
return pos + ie_len;
}
static u8 * wpa_add_kde(u8 *pos, u32 kde, const u8 *data, size_t data_len)
{
*pos++ = WLAN_EID_VENDOR_SPECIFIC;
*pos++ = RSN_SELECTOR_LEN + data_len;
RSN_SELECTOR_PUT(pos, kde);
pos += RSN_SELECTOR_LEN;
os_memcpy(pos, data, data_len);
pos += data_len;
return pos;
}
static void wpa_supplicant_smk_timeout(void *eloop_ctx, void *timeout_ctx)
{
#if 0
struct wpa_sm *sm = eloop_ctx;
struct wpa_peerkey *peerkey = timeout_ctx;
#endif
/* TODO: time out SMK and any STK that was generated using this SMK */
}
static void wpa_supplicant_peerkey_free(struct wpa_sm *sm,
struct wpa_peerkey *peerkey)
{
eloop_cancel_timeout(wpa_supplicant_smk_timeout, sm, peerkey);
os_free(peerkey);
}
static int wpa_supplicant_send_smk_error(struct wpa_sm *sm, const u8 *dst,
const u8 *peer,
u16 mui, u16 error_type, int ver)
{
size_t rlen;
struct wpa_eapol_key *err;
struct rsn_error_kde error;
u8 *rbuf, *pos;
size_t kde_len;
u16 key_info;
kde_len = 2 + RSN_SELECTOR_LEN + sizeof(error);
if (peer)
kde_len += 2 + RSN_SELECTOR_LEN + ETH_ALEN;
rbuf = wpa_sm_alloc_eapol(sm, IEEE802_1X_TYPE_EAPOL_KEY,
NULL, sizeof(*err) + kde_len, &rlen,
(void *) &err);
if (rbuf == NULL)
return -1;
err->type = EAPOL_KEY_TYPE_RSN;
key_info = ver | WPA_KEY_INFO_SMK_MESSAGE | WPA_KEY_INFO_MIC |
WPA_KEY_INFO_SECURE | WPA_KEY_INFO_ERROR |
WPA_KEY_INFO_REQUEST;
WPA_PUT_BE16(err->key_info, key_info);
WPA_PUT_BE16(err->key_length, 0);
os_memcpy(err->replay_counter, sm->request_counter,
WPA_REPLAY_COUNTER_LEN);
inc_byte_array(sm->request_counter, WPA_REPLAY_COUNTER_LEN);
WPA_PUT_BE16(err->key_data_length, (u16) kde_len);
pos = (u8 *) (err + 1);
if (peer) {
/* Peer MAC Address KDE */
pos = wpa_add_kde(pos, RSN_KEY_DATA_MAC_ADDR, peer, ETH_ALEN);
}
/* Error KDE */
error.mui = host_to_be16(mui);
error.error_type = host_to_be16(error_type);
wpa_add_kde(pos, RSN_KEY_DATA_ERROR, (u8 *) &error, sizeof(error));
if (peer) {
wpa_printf(MSG_DEBUG, "RSN: Sending EAPOL-Key SMK Error (peer "
MACSTR " mui %d error_type %d)",
MAC2STR(peer), mui, error_type);
} else {
wpa_printf(MSG_DEBUG, "RSN: Sending EAPOL-Key SMK Error "
"(mui %d error_type %d)", mui, error_type);
}
wpa_eapol_key_send(sm, sm->ptk.kck, ver, dst, ETH_P_EAPOL,
rbuf, rlen, err->key_mic);
return 0;
}
static int wpa_supplicant_send_smk_m3(struct wpa_sm *sm,
const unsigned char *src_addr,
const struct wpa_eapol_key *key,
int ver, struct wpa_peerkey *peerkey)
{
size_t rlen;
struct wpa_eapol_key *reply;
u8 *rbuf, *pos;
size_t kde_len;
u16 key_info;
/* KDEs: Peer RSN IE, Initiator MAC Address, Initiator Nonce */
kde_len = peerkey->rsnie_p_len +
2 + RSN_SELECTOR_LEN + ETH_ALEN +
2 + RSN_SELECTOR_LEN + WPA_NONCE_LEN;
rbuf = wpa_sm_alloc_eapol(sm, IEEE802_1X_TYPE_EAPOL_KEY,
NULL, sizeof(*reply) + kde_len, &rlen,
(void *) &reply);
if (rbuf == NULL)
return -1;
reply->type = EAPOL_KEY_TYPE_RSN;
key_info = ver | WPA_KEY_INFO_SMK_MESSAGE | WPA_KEY_INFO_MIC |
WPA_KEY_INFO_SECURE;
WPA_PUT_BE16(reply->key_info, key_info);
WPA_PUT_BE16(reply->key_length, 0);
os_memcpy(reply->replay_counter, key->replay_counter,
WPA_REPLAY_COUNTER_LEN);
os_memcpy(reply->key_nonce, peerkey->pnonce, WPA_NONCE_LEN);
WPA_PUT_BE16(reply->key_data_length, (u16) kde_len);
pos = (u8 *) (reply + 1);
/* Peer RSN IE */
pos = wpa_add_ie(pos, peerkey->rsnie_p, peerkey->rsnie_p_len);
/* Initiator MAC Address KDE */
pos = wpa_add_kde(pos, RSN_KEY_DATA_MAC_ADDR, peerkey->addr, ETH_ALEN);
/* Initiator Nonce */
wpa_add_kde(pos, RSN_KEY_DATA_NONCE, peerkey->inonce, WPA_NONCE_LEN);
wpa_printf(MSG_DEBUG, "RSN: Sending EAPOL-Key SMK M3");
wpa_eapol_key_send(sm, sm->ptk.kck, ver, src_addr, ETH_P_EAPOL,
rbuf, rlen, reply->key_mic);
return 0;
}
static int wpa_supplicant_process_smk_m2(
struct wpa_sm *sm, const unsigned char *src_addr,
const struct wpa_eapol_key *key, size_t extra_len, int ver)
{
struct wpa_peerkey *peerkey;
struct wpa_eapol_ie_parse kde;
struct wpa_ie_data ie;
int cipher;
struct rsn_ie_hdr *hdr;
u8 *pos;
wpa_printf(MSG_DEBUG, "RSN: Received SMK M2");
if (!sm->peerkey_enabled || sm->proto != WPA_PROTO_RSN) {
wpa_printf(MSG_INFO, "RSN: SMK handshake not allowed for "
"the current network");
return -1;
}
if (wpa_supplicant_parse_ies((const u8 *) (key + 1), extra_len, &kde) <
0) {
wpa_printf(MSG_INFO, "RSN: Failed to parse KDEs in SMK M2");
return -1;
}
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 M2");
return -1;
}
wpa_printf(MSG_DEBUG, "RSN: SMK M2 - SMK initiator " MACSTR,
MAC2STR(kde.mac_addr));
if (kde.rsn_ie_len > PEERKEY_MAX_IE_LEN) {
wpa_printf(MSG_INFO, "RSN: Too long Initiator RSN IE in SMK "
"M2");
return -1;
}
if (wpa_parse_wpa_ie_rsn(kde.rsn_ie, kde.rsn_ie_len, &ie) < 0) {
wpa_printf(MSG_INFO, "RSN: Failed to parse RSN IE in SMK M2");
return -1;
}
cipher = ie.pairwise_cipher & sm->allowed_pairwise_cipher;
if (cipher & WPA_CIPHER_CCMP) {
wpa_printf(MSG_DEBUG, "RSN: Using CCMP for PeerKey");
cipher = WPA_CIPHER_CCMP;
} else if (cipher & WPA_CIPHER_TKIP) {
wpa_printf(MSG_DEBUG, "RSN: Using TKIP for PeerKey");
cipher = WPA_CIPHER_TKIP;
} else {
wpa_printf(MSG_INFO, "RSN: No acceptable cipher in SMK M2");
wpa_supplicant_send_smk_error(sm, src_addr, kde.mac_addr,
STK_MUI_SMK, STK_ERR_CPHR_NS,
ver);
return -1;
}
/* TODO: find existing entry and if found, use that instead of adding
* a new one; how to handle the case where both ends initiate at the
* same time? */
peerkey = os_zalloc(sizeof(*peerkey));
if (peerkey == NULL)
return -1;
os_memcpy(peerkey->addr, kde.mac_addr, ETH_ALEN);
os_memcpy(peerkey->inonce, key->key_nonce, WPA_NONCE_LEN);
os_memcpy(peerkey->rsnie_i, kde.rsn_ie, kde.rsn_ie_len);
peerkey->rsnie_i_len = kde.rsn_ie_len;
peerkey->cipher = cipher;
#ifdef CONFIG_IEEE80211W
if (ie.key_mgmt & (WPA_KEY_MGMT_IEEE8021X_SHA256 |
WPA_KEY_MGMT_PSK_SHA256))
peerkey->use_sha256 = 1;
#endif /* CONFIG_IEEE80211W */
if (os_get_random(peerkey->pnonce, WPA_NONCE_LEN)) {
wpa_msg(sm->ctx->msg_ctx, MSG_WARNING,
"WPA: Failed to get random data for PNonce");
wpa_supplicant_peerkey_free(sm, peerkey);
return -1;
}
hdr = (struct rsn_ie_hdr *) peerkey->rsnie_p;
hdr->elem_id = WLAN_EID_RSN;
WPA_PUT_LE16(hdr->version, RSN_VERSION);
pos = (u8 *) (hdr + 1);
/* Group Suite can be anything for SMK RSN IE; receiver will just
* ignore it. */
RSN_SELECTOR_PUT(pos, RSN_CIPHER_SUITE_CCMP);
pos += RSN_SELECTOR_LEN;
/* Include only the selected cipher in pairwise cipher suite */
WPA_PUT_LE16(pos, 1);
pos += 2;
if (cipher == WPA_CIPHER_CCMP)
RSN_SELECTOR_PUT(pos, RSN_CIPHER_SUITE_CCMP);
else if (cipher == WPA_CIPHER_TKIP)
RSN_SELECTOR_PUT(pos, RSN_CIPHER_SUITE_TKIP);
pos += RSN_SELECTOR_LEN;
hdr->len = (pos - peerkey->rsnie_p) - 2;
peerkey->rsnie_p_len = pos - peerkey->rsnie_p;
wpa_hexdump(MSG_DEBUG, "WPA: RSN IE for SMK handshake",
peerkey->rsnie_p, peerkey->rsnie_p_len);
wpa_supplicant_send_smk_m3(sm, src_addr, key, ver, peerkey);
peerkey->next = sm->peerkey;
sm->peerkey = peerkey;
return 0;
}
/**
* rsn_smkid - Derive SMK identifier
* @smk: Station master key (32 bytes)
* @pnonce: Peer Nonce
* @mac_p: Peer MAC address
* @inonce: Initiator Nonce
* @mac_i: Initiator MAC address
* @use_sha256: Whether to use SHA256-based KDF
*
* 8.5.1.4 Station to station (STK) key hierarchy
* SMKID = HMAC-SHA1-128(SMK, "SMK Name" || PNonce || MAC_P || INonce || MAC_I)
*/
static void rsn_smkid(const u8 *smk, const u8 *pnonce, const u8 *mac_p,
const u8 *inonce, const u8 *mac_i, u8 *smkid,
int use_sha256)
{
char *title = "SMK Name";
const u8 *addr[5];
const size_t len[5] = { 8, WPA_NONCE_LEN, ETH_ALEN, WPA_NONCE_LEN,
ETH_ALEN };
unsigned char hash[SHA256_MAC_LEN];
addr[0] = (u8 *) title;
addr[1] = pnonce;
addr[2] = mac_p;
addr[3] = inonce;
addr[4] = mac_i;
#ifdef CONFIG_IEEE80211W
if (use_sha256)
hmac_sha256_vector(smk, PMK_LEN, 5, addr, len, hash);
else
#endif /* CONFIG_IEEE80211W */
hmac_sha1_vector(smk, PMK_LEN, 5, addr, len, hash);
os_memcpy(smkid, hash, PMKID_LEN);
}
static void wpa_supplicant_send_stk_1_of_4(struct wpa_sm *sm,
struct wpa_peerkey *peerkey)
{
size_t mlen;
struct wpa_eapol_key *msg;
u8 *mbuf;
size_t kde_len;
u16 key_info, ver;
kde_len = 2 + RSN_SELECTOR_LEN + PMKID_LEN;
mbuf = wpa_sm_alloc_eapol(sm, IEEE802_1X_TYPE_EAPOL_KEY, NULL,
sizeof(*msg) + kde_len, &mlen,
(void *) &msg);
if (mbuf == NULL)
return;
msg->type = EAPOL_KEY_TYPE_RSN;
if (peerkey->cipher == WPA_CIPHER_CCMP)
ver = WPA_KEY_INFO_TYPE_HMAC_SHA1_AES;
else
ver = WPA_KEY_INFO_TYPE_HMAC_MD5_RC4;
key_info = ver | WPA_KEY_INFO_KEY_TYPE | WPA_KEY_INFO_ACK;
WPA_PUT_BE16(msg->key_info, key_info);
if (peerkey->cipher == WPA_CIPHER_CCMP)
WPA_PUT_BE16(msg->key_length, 16);
else
WPA_PUT_BE16(msg->key_length, 32);
os_memcpy(msg->replay_counter, peerkey->replay_counter,
WPA_REPLAY_COUNTER_LEN);
inc_byte_array(peerkey->replay_counter, WPA_REPLAY_COUNTER_LEN);
WPA_PUT_BE16(msg->key_data_length, kde_len);
wpa_add_kde((u8 *) (msg + 1), RSN_KEY_DATA_PMKID,
peerkey->smkid, PMKID_LEN);
if (os_get_random(peerkey->inonce, WPA_NONCE_LEN)) {
wpa_msg(sm->ctx->msg_ctx, MSG_WARNING,
"RSN: Failed to get random data for INonce (STK)");
os_free(mbuf);
return;
}
wpa_hexdump(MSG_DEBUG, "RSN: INonce for STK 4-Way Handshake",
peerkey->inonce, WPA_NONCE_LEN);
os_memcpy(msg->key_nonce, peerkey->inonce, WPA_NONCE_LEN);
wpa_printf(MSG_DEBUG, "RSN: Sending EAPOL-Key STK 1/4 to " MACSTR,
MAC2STR(peerkey->addr));
wpa_eapol_key_send(sm, NULL, ver, peerkey->addr, ETH_P_EAPOL,
mbuf, mlen, NULL);
}
static void wpa_supplicant_send_stk_3_of_4(struct wpa_sm *sm,
struct wpa_peerkey *peerkey)
{
size_t mlen;
struct wpa_eapol_key *msg;
u8 *mbuf, *pos;
size_t kde_len;
u16 key_info, ver;
be32 lifetime;
kde_len = peerkey->rsnie_i_len +
2 + RSN_SELECTOR_LEN + sizeof(lifetime);
mbuf = wpa_sm_alloc_eapol(sm, IEEE802_1X_TYPE_EAPOL_KEY, NULL,
sizeof(*msg) + kde_len, &mlen,
(void *) &msg);
if (mbuf == NULL)
return;
msg->type = EAPOL_KEY_TYPE_RSN;
if (peerkey->cipher == WPA_CIPHER_CCMP)
ver = WPA_KEY_INFO_TYPE_HMAC_SHA1_AES;
else
ver = WPA_KEY_INFO_TYPE_HMAC_MD5_RC4;
key_info = ver | WPA_KEY_INFO_KEY_TYPE | WPA_KEY_INFO_ACK |
WPA_KEY_INFO_MIC | WPA_KEY_INFO_SECURE;
WPA_PUT_BE16(msg->key_info, key_info);
if (peerkey->cipher == WPA_CIPHER_CCMP)
WPA_PUT_BE16(msg->key_length, 16);
else
WPA_PUT_BE16(msg->key_length, 32);
os_memcpy(msg->replay_counter, peerkey->replay_counter,
WPA_REPLAY_COUNTER_LEN);
inc_byte_array(peerkey->replay_counter, WPA_REPLAY_COUNTER_LEN);
WPA_PUT_BE16(msg->key_data_length, kde_len);
pos = (u8 *) (msg + 1);
pos = wpa_add_ie(pos, peerkey->rsnie_i, peerkey->rsnie_i_len);
lifetime = host_to_be32(peerkey->lifetime);
wpa_add_kde(pos, RSN_KEY_DATA_LIFETIME,
(u8 *) &lifetime, sizeof(lifetime));
os_memcpy(msg->key_nonce, peerkey->inonce, WPA_NONCE_LEN);
wpa_printf(MSG_DEBUG, "RSN: Sending EAPOL-Key STK 3/4 to " MACSTR,
MAC2STR(peerkey->addr));
wpa_eapol_key_send(sm, peerkey->stk.kck, ver, peerkey->addr,
ETH_P_EAPOL, mbuf, mlen, msg->key_mic);
}
static int wpa_supplicant_process_smk_m4(struct wpa_peerkey *peerkey,
struct wpa_eapol_ie_parse *kde)
{
wpa_printf(MSG_DEBUG, "RSN: Received SMK M4 (Initiator " MACSTR ")",
MAC2STR(kde->mac_addr));
if (os_memcmp(kde->smk + PMK_LEN, peerkey->pnonce, WPA_NONCE_LEN) != 0)
{
wpa_printf(MSG_INFO, "RSN: PNonce in SMK KDE does not "
"match with the one used in SMK M3");
return -1;
}
if (os_memcmp(kde->nonce, peerkey->inonce, WPA_NONCE_LEN) != 0) {
wpa_printf(MSG_INFO, "RSN: INonce in SMK M4 did not "
"match with the one received in SMK M2");
return -1;
}
return 0;
}
static int wpa_supplicant_process_smk_m5(struct wpa_sm *sm,
const unsigned char *src_addr,
const struct wpa_eapol_key *key,
int ver,
struct wpa_peerkey *peerkey,
struct wpa_eapol_ie_parse *kde)
{
int cipher;
struct wpa_ie_data ie;
wpa_printf(MSG_DEBUG, "RSN: Received SMK M5 (Peer " MACSTR ")",
MAC2STR(kde->mac_addr));
if (kde->rsn_ie == NULL || kde->rsn_ie_len > PEERKEY_MAX_IE_LEN ||
wpa_parse_wpa_ie_rsn(kde->rsn_ie, kde->rsn_ie_len, &ie) < 0) {
wpa_printf(MSG_INFO, "RSN: No RSN IE in SMK M5");
/* TODO: abort negotiation */
return -1;
}
if (os_memcmp(key->key_nonce, peerkey->inonce, WPA_NONCE_LEN) != 0) {
wpa_printf(MSG_INFO, "RSN: Key Nonce in SMK M5 does "
"not match with INonce used in SMK M1");
return -1;
}
if (os_memcmp(kde->smk + PMK_LEN, peerkey->inonce, WPA_NONCE_LEN) != 0)
{
wpa_printf(MSG_INFO, "RSN: INonce in SMK KDE does not "
"match with the one used in SMK M1");
return -1;
}
os_memcpy(peerkey->rsnie_p, kde->rsn_ie, kde->rsn_ie_len);
peerkey->rsnie_p_len = kde->rsn_ie_len;
os_memcpy(peerkey->pnonce, kde->nonce, WPA_NONCE_LEN);
cipher = ie.pairwise_cipher & sm->allowed_pairwise_cipher;
if (cipher & WPA_CIPHER_CCMP) {
wpa_printf(MSG_DEBUG, "RSN: Using CCMP for PeerKey");
peerkey->cipher = WPA_CIPHER_CCMP;
} else if (cipher & WPA_CIPHER_TKIP) {
wpa_printf(MSG_DEBUG, "RSN: Using TKIP for PeerKey");
peerkey->cipher = WPA_CIPHER_TKIP;
} else {
wpa_printf(MSG_INFO, "RSN: SMK Peer STA " MACSTR " selected "
"unacceptable cipher", MAC2STR(kde->mac_addr));
wpa_supplicant_send_smk_error(sm, src_addr, kde->mac_addr,
STK_MUI_SMK, STK_ERR_CPHR_NS,
ver);
/* TODO: abort negotiation */
return -1;
}
return 0;
}
static int wpa_supplicant_process_smk_m45(
struct wpa_sm *sm, const unsigned char *src_addr,
const struct wpa_eapol_key *key, size_t extra_len, int ver)
{
struct wpa_peerkey *peerkey;
struct wpa_eapol_ie_parse kde;
u32 lifetime;
struct os_time now;
if (!sm->peerkey_enabled || sm->proto != WPA_PROTO_RSN) {
wpa_printf(MSG_DEBUG, "RSN: SMK handshake not allowed for "
"the current network");
return -1;
}
if (wpa_supplicant_parse_ies((const u8 *) (key + 1), extra_len, &kde) <
0) {
wpa_printf(MSG_INFO, "RSN: Failed to parse KDEs in SMK M4/M5");
return -1;
}
if (kde.mac_addr == NULL || kde.mac_addr_len < ETH_ALEN ||
kde.nonce == NULL || kde.nonce_len < WPA_NONCE_LEN ||
kde.smk == NULL || kde.smk_len < PMK_LEN + WPA_NONCE_LEN ||
kde.lifetime == NULL || kde.lifetime_len < 4) {
wpa_printf(MSG_INFO, "RSN: No MAC Address, Nonce, SMK, or "
"Lifetime KDE in SMK M4/M5");
return -1;
}
for (peerkey = sm->peerkey; peerkey; peerkey = peerkey->next) {
if (os_memcmp(peerkey->addr, kde.mac_addr, ETH_ALEN) == 0 &&
os_memcmp(peerkey->initiator ? peerkey->inonce :
peerkey->pnonce,
key->key_nonce, WPA_NONCE_LEN) == 0)
break;
}
if (peerkey == NULL) {
wpa_printf(MSG_INFO, "RSN: No matching SMK handshake found "
"for SMK M4/M5: peer " MACSTR,
MAC2STR(kde.mac_addr));
return -1;
}
if (peerkey->initiator) {
if (wpa_supplicant_process_smk_m5(sm, src_addr, key, ver,
peerkey, &kde) < 0)
return -1;
} else {
if (wpa_supplicant_process_smk_m4(peerkey, &kde) < 0)
return -1;
}
os_memcpy(peerkey->smk, kde.smk, PMK_LEN);
peerkey->smk_complete = 1;
wpa_hexdump_key(MSG_DEBUG, "RSN: SMK", peerkey->smk, PMK_LEN);
lifetime = WPA_GET_BE32(kde.lifetime);
wpa_printf(MSG_DEBUG, "RSN: SMK lifetime %u seconds", lifetime);
if (lifetime > 1000000000)
lifetime = 1000000000; /* avoid overflowing expiration time */
peerkey->lifetime = lifetime;
os_get_time(&now);
peerkey->expiration = now.sec + lifetime;
eloop_register_timeout(lifetime, 0, wpa_supplicant_smk_timeout,
sm, peerkey);
if (peerkey->initiator) {
rsn_smkid(peerkey->smk, peerkey->pnonce, peerkey->addr,
peerkey->inonce, sm->own_addr, peerkey->smkid,
peerkey->use_sha256);
wpa_supplicant_send_stk_1_of_4(sm, peerkey);
} else {
rsn_smkid(peerkey->smk, peerkey->pnonce, sm->own_addr,
peerkey->inonce, peerkey->addr, peerkey->smkid,
peerkey->use_sha256);
}
wpa_hexdump(MSG_DEBUG, "RSN: SMKID", peerkey->smkid, PMKID_LEN);
return 0;
}
static int wpa_supplicant_process_smk_error(
struct wpa_sm *sm, const unsigned char *src_addr,
const struct wpa_eapol_key *key, size_t extra_len)
{
struct wpa_eapol_ie_parse kde;
struct rsn_error_kde error;
u8 peer[ETH_ALEN];
u16 error_type;
wpa_printf(MSG_DEBUG, "RSN: Received SMK Error");
if (!sm->peerkey_enabled || sm->proto != WPA_PROTO_RSN) {
wpa_printf(MSG_DEBUG, "RSN: SMK handshake not allowed for "
"the current network");
return -1;
}
if (wpa_supplicant_parse_ies((const u8 *) (key + 1), extra_len, &kde) <
0) {
wpa_printf(MSG_INFO, "RSN: Failed to parse KDEs in SMK Error");
return -1;
}
if (kde.error == NULL || kde.error_len < sizeof(error)) {
wpa_printf(MSG_INFO, "RSN: No Error KDE in SMK Error");
return -1;
}
if (kde.mac_addr && kde.mac_addr_len >= ETH_ALEN)
os_memcpy(peer, kde.mac_addr, ETH_ALEN);
else
os_memset(peer, 0, ETH_ALEN);
os_memcpy(&error, kde.error, sizeof(error));
error_type = be_to_host16(error.error_type);
wpa_msg(sm->ctx->msg_ctx, MSG_INFO,
"RSN: SMK Error KDE received: MUI %d error_type %d peer "
MACSTR,
be_to_host16(error.mui), error_type,
MAC2STR(peer));
if (kde.mac_addr &&
(error_type == STK_ERR_STA_NR || error_type == STK_ERR_STA_NRSN ||
error_type == STK_ERR_CPHR_NS)) {
struct wpa_peerkey *peerkey;
for (peerkey = sm->peerkey; peerkey; peerkey = peerkey->next) {
if (os_memcmp(peerkey->addr, kde.mac_addr, ETH_ALEN) ==
0)
break;
}
if (peerkey == NULL) {
wpa_printf(MSG_DEBUG, "RSN: No matching SMK handshake "
"found for SMK Error");
return -1;
}
/* TODO: abort SMK/STK handshake and remove all related keys */
}
return 0;
}
static void wpa_supplicant_process_stk_1_of_4(struct wpa_sm *sm,
struct wpa_peerkey *peerkey,
const struct wpa_eapol_key *key,
u16 ver)
{
struct wpa_eapol_ie_parse ie;
const u8 *kde;
size_t len, kde_buf_len;
struct wpa_ptk *stk;
u8 buf[8], *kde_buf, *pos;
be32 lifetime;
wpa_printf(MSG_DEBUG, "RSN: RX message 1 of STK 4-Way Handshake from "
MACSTR " (ver=%d)", MAC2STR(peerkey->addr), ver);
os_memset(&ie, 0, sizeof(ie));
/* RSN: msg 1/4 should contain SMKID for the selected SMK */
kde = (const u8 *) (key + 1);
len = WPA_GET_BE16(key->key_data_length);
wpa_hexdump(MSG_DEBUG, "RSN: msg 1/4 key data", kde, len);
if (wpa_supplicant_parse_ies(kde, len, &ie) < 0 || ie.pmkid == NULL) {
wpa_printf(MSG_DEBUG, "RSN: No SMKID in STK 1/4");
return;
}
if (os_memcmp(ie.pmkid, peerkey->smkid, PMKID_LEN) != 0) {
wpa_hexdump(MSG_DEBUG, "RSN: Unknown SMKID in STK 1/4",
ie.pmkid, PMKID_LEN);
return;
}
if (os_get_random(peerkey->pnonce, WPA_NONCE_LEN)) {
wpa_msg(sm->ctx->msg_ctx, MSG_WARNING,
"RSN: Failed to get random data for PNonce");
return;
}
wpa_hexdump(MSG_DEBUG, "WPA: Renewed PNonce",
peerkey->pnonce, WPA_NONCE_LEN);
/* Calculate STK which will be stored as a temporary STK until it has
* been verified when processing message 3/4. */
stk = &peerkey->tstk;
wpa_pmk_to_ptk(peerkey->smk, PMK_LEN, "Peer key expansion",
sm->own_addr, peerkey->addr,
peerkey->pnonce, key->key_nonce,
(u8 *) stk, sizeof(*stk),
peerkey->use_sha256);
/* Supplicant: swap tx/rx Mic keys */
os_memcpy(buf, stk->u.auth.tx_mic_key, 8);
os_memcpy(stk->u.auth.tx_mic_key, stk->u.auth.rx_mic_key, 8);
os_memcpy(stk->u.auth.rx_mic_key, buf, 8);
peerkey->tstk_set = 1;
kde_buf_len = peerkey->rsnie_p_len +
2 + RSN_SELECTOR_LEN + sizeof(lifetime) +
2 + RSN_SELECTOR_LEN + PMKID_LEN;
kde_buf = os_malloc(kde_buf_len);
if (kde_buf == NULL)
return;
pos = kde_buf;
pos = wpa_add_ie(pos, peerkey->rsnie_p, peerkey->rsnie_p_len);
lifetime = host_to_be32(peerkey->lifetime);
pos = wpa_add_kde(pos, RSN_KEY_DATA_LIFETIME,
(u8 *) &lifetime, sizeof(lifetime));
wpa_add_kde(pos, RSN_KEY_DATA_PMKID, peerkey->smkid, PMKID_LEN);
if (wpa_supplicant_send_2_of_4(sm, peerkey->addr, key, ver,
peerkey->pnonce, kde_buf, kde_buf_len,
stk)) {
os_free(kde_buf);
return;
}
os_free(kde_buf);
os_memcpy(peerkey->inonce, key->key_nonce, WPA_NONCE_LEN);
}
static void wpa_supplicant_update_smk_lifetime(struct wpa_sm *sm,
struct wpa_peerkey *peerkey,
struct wpa_eapol_ie_parse *kde)
{
u32 lifetime;
struct os_time now;
if (kde->lifetime == NULL || kde->lifetime_len < sizeof(lifetime))
return;
lifetime = WPA_GET_BE32(kde->lifetime);
if (lifetime >= peerkey->lifetime) {
wpa_printf(MSG_DEBUG, "RSN: Peer used SMK lifetime %u seconds "
"which is larger than or equal to own value %u "
"seconds - ignored", lifetime, peerkey->lifetime);
return;
}
wpa_printf(MSG_DEBUG, "RSN: Peer used shorter SMK lifetime %u seconds "
"(own was %u seconds) - updated",
lifetime, peerkey->lifetime);
peerkey->lifetime = lifetime;
os_get_time(&now);
peerkey->expiration = now.sec + lifetime;
eloop_cancel_timeout(wpa_supplicant_smk_timeout, sm, peerkey);
eloop_register_timeout(lifetime, 0, wpa_supplicant_smk_timeout,
sm, peerkey);
}
static void wpa_supplicant_process_stk_2_of_4(struct wpa_sm *sm,
struct wpa_peerkey *peerkey,
const struct wpa_eapol_key *key,
u16 ver)
{
struct wpa_eapol_ie_parse kde;
const u8 *keydata;
size_t len;
wpa_printf(MSG_DEBUG, "RSN: RX message 2 of STK 4-Way Handshake from "
MACSTR " (ver=%d)", MAC2STR(peerkey->addr), ver);
os_memset(&kde, 0, sizeof(kde));
/* RSN: msg 2/4 should contain SMKID for the selected SMK and RSN IE
* from the peer. It may also include Lifetime KDE. */
keydata = (const u8 *) (key + 1);
len = WPA_GET_BE16(key->key_data_length);
wpa_hexdump(MSG_DEBUG, "RSN: msg 2/4 key data", keydata, len);
if (wpa_supplicant_parse_ies(keydata, len, &kde) < 0 ||
kde.pmkid == NULL || kde.rsn_ie == NULL) {
wpa_printf(MSG_DEBUG, "RSN: No SMKID or RSN IE in STK 2/4");
return;
}
if (os_memcmp(kde.pmkid, peerkey->smkid, PMKID_LEN) != 0) {
wpa_hexdump(MSG_DEBUG, "RSN: Unknown SMKID in STK 2/4",
kde.pmkid, PMKID_LEN);
return;
}
if (kde.rsn_ie_len != peerkey->rsnie_p_len ||
os_memcmp(kde.rsn_ie, peerkey->rsnie_p, kde.rsn_ie_len) != 0) {
wpa_printf(MSG_INFO, "RSN: Peer RSN IE in SMK and STK "
"handshakes did not match");
wpa_hexdump(MSG_DEBUG, "RSN: Peer RSN IE in SMK handshake",
peerkey->rsnie_p, peerkey->rsnie_p_len);
wpa_hexdump(MSG_DEBUG, "RSN: Peer RSN IE in STK handshake",
kde.rsn_ie, kde.rsn_ie_len);
return;
}
wpa_supplicant_update_smk_lifetime(sm, peerkey, &kde);
wpa_supplicant_send_stk_3_of_4(sm, peerkey);
os_memcpy(peerkey->pnonce, key->key_nonce, WPA_NONCE_LEN);
}
static void wpa_supplicant_process_stk_3_of_4(struct wpa_sm *sm,
struct wpa_peerkey *peerkey,
const struct wpa_eapol_key *key,
u16 ver)
{
struct wpa_eapol_ie_parse kde;
const u8 *keydata;
size_t len, key_len;
const u8 *_key;
u8 key_buf[32], rsc[6];
wpa_printf(MSG_DEBUG, "RSN: RX message 3 of STK 4-Way Handshake from "
MACSTR " (ver=%d)", MAC2STR(peerkey->addr), ver);
os_memset(&kde, 0, sizeof(kde));
/* RSN: msg 3/4 should contain Initiator RSN IE. It may also include
* Lifetime KDE. */
keydata = (const u8 *) (key + 1);
len = WPA_GET_BE16(key->key_data_length);
wpa_hexdump(MSG_DEBUG, "RSN: msg 3/4 key data", keydata, len);
if (wpa_supplicant_parse_ies(keydata, len, &kde) < 0) {
wpa_printf(MSG_DEBUG, "RSN: Failed to parse key data in "
"STK 3/4");
return;
}
if (kde.rsn_ie_len != peerkey->rsnie_i_len ||
os_memcmp(kde.rsn_ie, peerkey->rsnie_i, kde.rsn_ie_len) != 0) {
wpa_printf(MSG_INFO, "RSN: Initiator RSN IE in SMK and STK "
"handshakes did not match");
wpa_hexdump(MSG_DEBUG, "RSN: Initiator RSN IE in SMK "
"handshake",
peerkey->rsnie_i, peerkey->rsnie_i_len);
wpa_hexdump(MSG_DEBUG, "RSN: Initiator RSN IE in STK "
"handshake",
kde.rsn_ie, kde.rsn_ie_len);
return;
}
if (os_memcmp(peerkey->inonce, key->key_nonce, WPA_NONCE_LEN) != 0) {
wpa_printf(MSG_WARNING, "RSN: INonce from message 1 of STK "
"4-Way Handshake differs from 3 of STK 4-Way "
"Handshake - drop packet (src=" MACSTR ")",
MAC2STR(peerkey->addr));
return;
}
wpa_supplicant_update_smk_lifetime(sm, peerkey, &kde);
if (wpa_supplicant_send_4_of_4(sm, peerkey->addr, key, ver,
WPA_GET_BE16(key->key_info),
NULL, 0, &peerkey->stk))
return;
_key = (u8 *) peerkey->stk.tk1;
if (peerkey->cipher == WPA_CIPHER_TKIP) {
/* Swap Tx/Rx keys for Michael MIC */
os_memcpy(key_buf, _key, 16);
os_memcpy(key_buf + 16, peerkey->stk.u.auth.rx_mic_key, 8);
os_memcpy(key_buf + 24, peerkey->stk.u.auth.tx_mic_key, 8);
_key = key_buf;
key_len = 32;
} else
key_len = 16;
os_memset(rsc, 0, 6);
if (wpa_sm_set_key(sm, peerkey->cipher, peerkey->addr, 0, 1,
rsc, sizeof(rsc), _key, key_len) < 0) {
wpa_printf(MSG_WARNING, "RSN: Failed to set STK to the "
"driver.");
return;
}
}
static void wpa_supplicant_process_stk_4_of_4(struct wpa_sm *sm,
struct wpa_peerkey *peerkey,
const struct wpa_eapol_key *key,
u16 ver)
{
u8 rsc[6];
wpa_printf(MSG_DEBUG, "RSN: RX message 4 of STK 4-Way Handshake from "
MACSTR " (ver=%d)", MAC2STR(peerkey->addr), ver);
os_memset(rsc, 0, 6);
if (wpa_sm_set_key(sm, peerkey->cipher, peerkey->addr, 0, 1,
rsc, sizeof(rsc), (u8 *) peerkey->stk.tk1,
peerkey->cipher == WPA_CIPHER_TKIP ? 32 : 16) < 0) {
wpa_printf(MSG_WARNING, "RSN: Failed to set STK to the "
"driver.");
return;
}
}
/**
* peerkey_verify_eapol_key_mic - Verify PeerKey MIC
* @sm: Pointer to WPA state machine data from wpa_sm_init()
* @peerkey: Pointer to the PeerKey data for the peer
* @key: Pointer to the EAPOL-Key frame header
* @ver: Version bits from EAPOL-Key Key Info
* @buf: Pointer to the beginning of EAPOL-Key frame
* @len: Length of the EAPOL-Key frame
* Returns: 0 on success, -1 on failure
*/
int peerkey_verify_eapol_key_mic(struct wpa_sm *sm,
struct wpa_peerkey *peerkey,
struct wpa_eapol_key *key, u16 ver,
const u8 *buf, size_t len)
{
u8 mic[16];
int ok = 0;
if (peerkey->initiator && !peerkey->stk_set) {
wpa_pmk_to_ptk(peerkey->smk, PMK_LEN, "Peer key expansion",
sm->own_addr, peerkey->addr,
peerkey->inonce, key->key_nonce,
(u8 *) &peerkey->stk, sizeof(peerkey->stk),
peerkey->use_sha256);
peerkey->stk_set = 1;
}
os_memcpy(mic, key->key_mic, 16);
if (peerkey->tstk_set) {
os_memset(key->key_mic, 0, 16);
wpa_eapol_key_mic(peerkey->tstk.kck, ver, buf, len,
key->key_mic);
if (os_memcmp(mic, key->key_mic, 16) != 0) {
wpa_printf(MSG_WARNING, "RSN: Invalid EAPOL-Key MIC "
"when using TSTK - ignoring TSTK");
} else {
ok = 1;
peerkey->tstk_set = 0;
peerkey->stk_set = 1;
os_memcpy(&peerkey->stk, &peerkey->tstk,
sizeof(peerkey->stk));
}
}
if (!ok && peerkey->stk_set) {
os_memset(key->key_mic, 0, 16);
wpa_eapol_key_mic(peerkey->stk.kck, ver, buf, len,
key->key_mic);
if (os_memcmp(mic, key->key_mic, 16) != 0) {
wpa_printf(MSG_WARNING, "RSN: Invalid EAPOL-Key MIC "
"- dropping packet");
return -1;
}
ok = 1;
}
if (!ok) {
wpa_printf(MSG_WARNING, "RSN: Could not verify EAPOL-Key MIC "
"- dropping packet");
return -1;
}
os_memcpy(peerkey->replay_counter, key->replay_counter,
WPA_REPLAY_COUNTER_LEN);
peerkey->replay_counter_set = 1;
return 0;
}
/**
* wpa_sm_stkstart - Send EAPOL-Key Request for STK handshake (STK M1)
* @sm: Pointer to WPA state machine data from wpa_sm_init()
* @peer: MAC address of the peer STA
* Returns: 0 on success, or -1 on failure
*
* Send an EAPOL-Key Request to the current authenticator to start STK
* handshake with the peer.
*/
int wpa_sm_stkstart(struct wpa_sm *sm, const u8 *peer)
{
size_t rlen, kde_len;
struct wpa_eapol_key *req;
int key_info, ver;
u8 bssid[ETH_ALEN], *rbuf, *pos, *count_pos;
u16 count;
struct rsn_ie_hdr *hdr;
struct wpa_peerkey *peerkey;
struct wpa_ie_data ie;
if (sm->proto != WPA_PROTO_RSN || !sm->ptk_set || !sm->peerkey_enabled)
return -1;
if (sm->ap_rsn_ie &&
wpa_parse_wpa_ie_rsn(sm->ap_rsn_ie, sm->ap_rsn_ie_len, &ie) == 0 &&
!(ie.capabilities & WPA_CAPABILITY_PEERKEY_ENABLED)) {
wpa_printf(MSG_DEBUG, "RSN: Current AP does not support STK");
return -1;
}
if (sm->pairwise_cipher == WPA_CIPHER_CCMP)
ver = WPA_KEY_INFO_TYPE_HMAC_SHA1_AES;
else
ver = WPA_KEY_INFO_TYPE_HMAC_MD5_RC4;
if (wpa_sm_get_bssid(sm, bssid) < 0) {
wpa_printf(MSG_WARNING, "Failed to read BSSID for EAPOL-Key "
"SMK M1");
return -1;
}
/* TODO: find existing entry and if found, use that instead of adding
* a new one */
peerkey = os_zalloc(sizeof(*peerkey));
if (peerkey == NULL)
return -1;
peerkey->initiator = 1;
os_memcpy(peerkey->addr, peer, ETH_ALEN);
#ifdef CONFIG_IEEE80211W
if (wpa_key_mgmt_sha256(sm->key_mgmt))
peerkey->use_sha256 = 1;
#endif /* CONFIG_IEEE80211W */
/* SMK M1:
* EAPOL-Key(S=1, M=1, A=0, I=0, K=0, SM=1, KeyRSC=0, Nonce=INonce,
* MIC=MIC, DataKDs=(RSNIE_I, MAC_P KDE))
*/
hdr = (struct rsn_ie_hdr *) peerkey->rsnie_i;
hdr->elem_id = WLAN_EID_RSN;
WPA_PUT_LE16(hdr->version, RSN_VERSION);
pos = (u8 *) (hdr + 1);
/* Group Suite can be anything for SMK RSN IE; receiver will just
* ignore it. */
RSN_SELECTOR_PUT(pos, RSN_CIPHER_SUITE_CCMP);
pos += RSN_SELECTOR_LEN;
count_pos = pos;
pos += 2;
count = 0;
if (sm->allowed_pairwise_cipher & WPA_CIPHER_CCMP) {
RSN_SELECTOR_PUT(pos, RSN_CIPHER_SUITE_CCMP);
pos += RSN_SELECTOR_LEN;
count++;
}
if (sm->allowed_pairwise_cipher & WPA_CIPHER_TKIP) {
RSN_SELECTOR_PUT(pos, RSN_CIPHER_SUITE_TKIP);
pos += RSN_SELECTOR_LEN;
count++;
}
WPA_PUT_LE16(count_pos, count);
hdr->len = (pos - peerkey->rsnie_i) - 2;
peerkey->rsnie_i_len = pos - peerkey->rsnie_i;
wpa_hexdump(MSG_DEBUG, "WPA: RSN IE for SMK handshake",
peerkey->rsnie_i, peerkey->rsnie_i_len);
kde_len = peerkey->rsnie_i_len + 2 + RSN_SELECTOR_LEN + ETH_ALEN;
rbuf = wpa_sm_alloc_eapol(sm, IEEE802_1X_TYPE_EAPOL_KEY, NULL,
sizeof(*req) + kde_len, &rlen,
(void *) &req);
if (rbuf == NULL) {
wpa_supplicant_peerkey_free(sm, peerkey);
return -1;
}
req->type = EAPOL_KEY_TYPE_RSN;
key_info = WPA_KEY_INFO_SMK_MESSAGE | WPA_KEY_INFO_MIC |
WPA_KEY_INFO_SECURE | WPA_KEY_INFO_REQUEST | ver;
WPA_PUT_BE16(req->key_info, key_info);
WPA_PUT_BE16(req->key_length, 0);
os_memcpy(req->replay_counter, sm->request_counter,
WPA_REPLAY_COUNTER_LEN);
inc_byte_array(sm->request_counter, WPA_REPLAY_COUNTER_LEN);
if (os_get_random(peerkey->inonce, WPA_NONCE_LEN)) {
wpa_msg(sm->ctx->msg_ctx, MSG_WARNING,
"WPA: Failed to get random data for INonce");
os_free(rbuf);
wpa_supplicant_peerkey_free(sm, peerkey);
return -1;
}
os_memcpy(req->key_nonce, peerkey->inonce, WPA_NONCE_LEN);
wpa_hexdump(MSG_DEBUG, "WPA: INonce for SMK handshake",
req->key_nonce, WPA_NONCE_LEN);
WPA_PUT_BE16(req->key_data_length, (u16) kde_len);
pos = (u8 *) (req + 1);
/* Initiator RSN IE */
pos = wpa_add_ie(pos, peerkey->rsnie_i, peerkey->rsnie_i_len);
/* Peer MAC address KDE */
wpa_add_kde(pos, RSN_KEY_DATA_MAC_ADDR, peer, ETH_ALEN);
wpa_printf(MSG_INFO, "RSN: Sending EAPOL-Key SMK M1 Request (peer "
MACSTR ")", MAC2STR(peer));
wpa_eapol_key_send(sm, sm->ptk.kck, ver, bssid, ETH_P_EAPOL,
rbuf, rlen, req->key_mic);
peerkey->next = sm->peerkey;
sm->peerkey = peerkey;
return 0;
}
/**
* peerkey_deinit - Free PeerKey values
* @sm: Pointer to WPA state machine data from wpa_sm_init()
*/
void peerkey_deinit(struct wpa_sm *sm)
{
struct wpa_peerkey *prev, *peerkey = sm->peerkey;
while (peerkey) {
prev = peerkey;
peerkey = peerkey->next;
os_free(prev);
}
}
void peerkey_rx_eapol_4way(struct wpa_sm *sm, struct wpa_peerkey *peerkey,
struct wpa_eapol_key *key, u16 key_info, u16 ver)
{
if ((key_info & (WPA_KEY_INFO_MIC | WPA_KEY_INFO_ACK)) ==
(WPA_KEY_INFO_MIC | WPA_KEY_INFO_ACK)) {
/* 3/4 STK 4-Way Handshake */
wpa_supplicant_process_stk_3_of_4(sm, peerkey, key, ver);
} else if (key_info & WPA_KEY_INFO_ACK) {
/* 1/4 STK 4-Way Handshake */
wpa_supplicant_process_stk_1_of_4(sm, peerkey, key, ver);
} else if (key_info & WPA_KEY_INFO_SECURE) {
/* 4/4 STK 4-Way Handshake */
wpa_supplicant_process_stk_4_of_4(sm, peerkey, key, ver);
} else {
/* 2/4 STK 4-Way Handshake */
wpa_supplicant_process_stk_2_of_4(sm, peerkey, key, ver);
}
}
void peerkey_rx_eapol_smk(struct wpa_sm *sm, const u8 *src_addr,
struct wpa_eapol_key *key, size_t extra_len,
u16 key_info, u16 ver)
{
if (key_info & WPA_KEY_INFO_ERROR) {
/* SMK Error */
wpa_supplicant_process_smk_error(sm, src_addr, key, extra_len);
} else if (key_info & WPA_KEY_INFO_ACK) {
/* SMK M2 */
wpa_supplicant_process_smk_m2(sm, src_addr, key, extra_len,
ver);
} else {
/* SMK M4 or M5 */
wpa_supplicant_process_smk_m45(sm, src_addr, key, extra_len,
ver);
}
}
#endif /* CONFIG_PEERKEY */