@@ -2872,6 +2872,8 @@ static int hostapd_config_fill(struct hostapd_config *conf,
}
} else if (os_strcmp(buf, "wpa") == 0) {
bss->wpa = atoi(pos);
+ } else if (os_strcmp(buf, "wpa_extended_key_id") == 0) {
+ bss->wpa_extended_key_id = atoi(pos);
} else if (os_strcmp(buf, "wpa_group_rekey") == 0) {
bss->wpa_group_rekey = atoi(pos);
bss->wpa_group_rekey_set = 1;
@@ -1471,6 +1471,16 @@ own_ip_addr=127.0.0.1
# wpa_key_mgmt=SAE for WPA3-Personal instead of wpa_key_mgmt=WPA-PSK).
#wpa=2
+# Extended Key ID support based on IEEE 802.11-2016
+#
+# Extended Key ID allows to rekey the PTK key without impact for ongoing
+# transmissions
+# When enabled and supported by the driver the AP will offer and support it for
+# stations. (The setting is only relevant with wpa=2)
+# 0 = force off
+# 1 = enable Extended Key ID support when driver supports it (Default)
+#wpa_extended_key_id=1
+
# WPA pre-shared keys for WPA-PSK. This can be either entered as a 256-bit
# secret in hex format (64 hex digits), wpa_psk, or as an ASCII passphrase
# (8..63 characters) that will be converted to PSK. This conversion uses SSID
@@ -61,6 +61,7 @@ void hostapd_config_defaults_bss(struct hostapd_bss_config *bss)
bss->broadcast_key_idx_max = 2;
bss->eap_reauth_period = 3600;
+ bss->wpa_extended_key_id = 1;
bss->wpa_group_rekey = 600;
bss->wpa_gmk_rekey = 86400;
bss->wpa_group_update_count = 4;
@@ -346,6 +346,7 @@ struct hostapd_bss_config {
* algorithms, WPA_AUTH_ALG_{OPEN,SHARED,LEAP} */
int wpa; /* bitfield of WPA_PROTO_WPA, WPA_PROTO_RSN */
+ int wpa_extended_key_id;
int wpa_key_mgmt;
#ifdef CONFIG_IEEE80211W
enum mfp_options ieee80211w;
@@ -80,6 +80,8 @@ u8 * hostapd_eid_osen(struct hostapd_data *hapd, u8 *eid)
/* 4 PTKSA replay counters when using WMM */
capab |= (RSN_NUM_REPLAY_COUNTERS_16 << 2);
}
+ if (hapd->conf->wpa_extended_key_id)
+ capab |= WPA_CAPABILITY_EXT_KEY_ID_FOR_UNICAST;
#ifdef CONFIG_IEEE80211W
if (hapd->conf->ieee80211w != NO_MGMT_FRAME_PROTECTION) {
capab |= WPA_CAPABILITY_MFPC;
@@ -755,6 +755,9 @@ static void wpa_request_new_ptk(struct wpa_state_machine *sm)
if (sm == NULL)
return;
+ if (sm->use_extended_key_id)
+ sm->keyidx_active ^= 1; /* flip keyID */
+
sm->PTKRequest = TRUE;
sm->PTK_valid = 0;
}
@@ -1459,6 +1462,12 @@ void __wpa_send_eapol(struct wpa_authenticator *wpa_auth,
else
version = WPA_KEY_INFO_TYPE_HMAC_MD5_RC4;
+ /* Extended Key ID must not be used for TKIP */
+ if (version == WPA_KEY_INFO_TYPE_HMAC_MD5_RC4) {
+ sm->use_extended_key_id = FALSE;
+ sm->keyidx_active = 0;
+ }
+
pairwise = !!(key_info & WPA_KEY_INFO_KEY_TYPE);
wpa_printf(MSG_DEBUG, "WPA: Send EAPOL(version=%d secure=%d mic=%d "
@@ -1717,6 +1726,11 @@ void wpa_remove_ptk(struct wpa_state_machine *sm)
0, KEY_TYPE_PAIRWISE))
wpa_printf(MSG_DEBUG,
"RSN: PTK removal from the driver failed");
+ if (sm->wpa_auth->conf.wpa_extended_key_id &&
+ wpa_auth_set_key(sm->wpa_auth, 0, WPA_ALG_NONE, sm->addr, 1, NULL,
+ 0, KEY_TYPE_PAIRWISE))
+ wpa_printf(MSG_DEBUG,
+ "RSN: PTK ID1 removal from the driver failed");
sm->pairwise_set = FALSE;
eloop_cancel_timeout(wpa_rekey_ptk, sm->wpa_auth, sm);
}
@@ -1775,6 +1789,8 @@ int wpa_auth_sm_event(struct wpa_state_machine *sm, enum wpa_event event)
sm->Init = FALSE;
sm->AuthenticationRequest = TRUE;
break;
+ } else if (sm->use_extended_key_id) {
+ sm->keyidx_active ^= 1; /* flip keyID */
}
if (sm->GUpdateStationKeys) {
/*
@@ -3142,7 +3158,7 @@ static int ocv_oci_add(struct wpa_state_machine *sm, u8 **argpos)
SM_STATE(WPA_PTK, PTKINITNEGOTIATING)
{
- u8 rsc[WPA_KEY_RSC_LEN], *_rsc, *gtk, *kde, *pos, dummy_gtk[32];
+ u8 rsc[WPA_KEY_RSC_LEN], *_rsc, *gtk, *kde, *pos, dummy_gtk[32], hdr[2];
size_t gtk_len, kde_len;
struct wpa_group *gsm = sm->group;
u8 *wpa_ie;
@@ -3183,6 +3199,18 @@ SM_STATE(WPA_PTK, PTKINITNEGOTIATING)
wpa_auth_logger(sm->wpa_auth, sm->addr, LOGGER_DEBUG,
"sending 3/4 msg of 4-Way Handshake");
if (sm->wpa == WPA_VERSION_WPA2) {
+ if (sm->use_extended_key_id && sm->TimeoutCtr == 1 &&
+ wpa_auth_set_key(sm->wpa_auth, 0,
+ wpa_cipher_to_alg(sm->pairwise),
+ sm->addr,
+ sm->keyidx_active, sm->PTK.tk,
+ wpa_cipher_key_len(sm->pairwise),
+ KEY_TYPE_NO_AUTO_TX)) {
+ wpa_sta_disconnect(sm->wpa_auth, sm->addr,
+ WLAN_REASON_PREV_AUTH_NOT_VALID);
+ return;
+ }
+
/* WPA2 send GTK in the 4-way handshake */
secure = 1;
gtk = gsm->GTK[gsm->GN - 1];
@@ -3223,6 +3251,10 @@ SM_STATE(WPA_PTK, PTKINITNEGOTIATING)
}
kde_len = wpa_ie_len + ieee80211w_kde_len(sm) + ocv_oci_len(sm);
+
+ if (sm->use_extended_key_id)
+ kde_len += 2 + RSN_SELECTOR_LEN + 2;
+
if (gtk)
kde_len += 2 + RSN_SELECTOR_LEN + 2 + gtk_len;
#ifdef CONFIG_IEEE80211R_AP
@@ -3259,10 +3291,15 @@ SM_STATE(WPA_PTK, PTKINITNEGOTIATING)
pos += elen;
}
#endif /* CONFIG_IEEE80211R_AP */
+ hdr[1] = 0;
+
+ if (sm->use_extended_key_id) {
+ hdr[0] = sm->keyidx_active & 0x01;
+ pos = wpa_add_kde(pos, RSN_KEY_DATA_KEYID, hdr, 2, NULL, 0);
+ }
+
if (gtk) {
- u8 hdr[2];
hdr[0] = gtkidx & 0x03;
- hdr[1] = 0;
pos = wpa_add_kde(pos, RSN_KEY_DATA_GROUPKEY, hdr, 2,
gtk, gtk_len);
}
@@ -3345,8 +3382,17 @@ SM_STATE(WPA_PTK, PTKINITDONE)
if (sm->Pair) {
enum wpa_alg alg = wpa_cipher_to_alg(sm->pairwise);
int klen = wpa_cipher_key_len(sm->pairwise);
- if (wpa_auth_set_key(sm->wpa_auth, 0, alg, sm->addr, 0,
- sm->PTK.tk, klen, KEY_TYPE_PAIRWISE)) {
+ if (sm->use_extended_key_id) {
+ if (wpa_auth_set_key(sm->wpa_auth, 0, 0, sm->addr,
+ sm->keyidx_active, NULL, 0,
+ KEY_TYPE_SET_TX)) {
+ wpa_sta_disconnect(sm->wpa_auth, sm->addr,
+ WLAN_REASON_PREV_AUTH_NOT_VALID);
+ return;
+ }
+ } else if (wpa_auth_set_key(sm->wpa_auth, 0, alg, sm->addr, 0,
+ sm->PTK.tk, klen,
+ KEY_TYPE_PAIRWISE)) {
wpa_sta_disconnect(sm->wpa_auth, sm->addr,
WLAN_REASON_PREV_AUTH_NOT_VALID);
return;
@@ -4980,7 +5026,7 @@ int wpa_auth_resend_m3(struct wpa_state_machine *sm,
void (*cb)(void *ctx1, void *ctx2),
void *ctx1, void *ctx2)
{
- u8 rsc[WPA_KEY_RSC_LEN], *_rsc, *gtk, *kde, *pos;
+ u8 rsc[WPA_KEY_RSC_LEN], *_rsc, *gtk, *kde, *pos, hdr[2];
#ifdef CONFIG_IEEE80211W
u8 *opos;
#endif /* CONFIG_IEEE80211W */
@@ -5040,6 +5086,10 @@ int wpa_auth_resend_m3(struct wpa_state_machine *sm,
}
kde_len = wpa_ie_len + ieee80211w_kde_len(sm) + ocv_oci_len(sm);
+
+ if (sm->use_extended_key_id)
+ kde_len += 2 + RSN_SELECTOR_LEN + 2;
+
if (gtk)
kde_len += 2 + RSN_SELECTOR_LEN + 2 + gtk_len;
#ifdef CONFIG_IEEE80211R_AP
@@ -5072,10 +5122,15 @@ int wpa_auth_resend_m3(struct wpa_state_machine *sm,
pos += elen;
}
#endif /* CONFIG_IEEE80211R_AP */
+ hdr[1] = 0;
+
+ if (sm->use_extended_key_id) {
+ hdr[0] = sm->keyidx_active & 0x03;
+ pos = wpa_add_kde(pos, RSN_KEY_DATA_KEYID, hdr, 2, NULL, 0);
+ }
+
if (gtk) {
- u8 hdr[2];
hdr[0] = gtkidx & 0x03;
- hdr[1] = 0;
pos = wpa_add_kde(pos, RSN_KEY_DATA_GROUPKEY, hdr, 2,
gtk, gtk_len);
}
@@ -169,6 +169,7 @@ struct ft_remote_r1kh {
struct wpa_auth_config {
int wpa;
+ int wpa_extended_key_id;
int wpa_key_mgmt;
int wpa_pairwise;
int wpa_group;
@@ -2652,7 +2652,7 @@ void wpa_ft_install_ptk(struct wpa_state_machine *sm)
* again after association to get the PTK configured, but that could be
* optimized by adding the STA entry earlier.
*/
- if (wpa_auth_set_key(sm->wpa_auth, 0, alg, sm->addr, 0,
+ if (wpa_auth_set_key(sm->wpa_auth, 0, alg, sm->addr, sm->keyidx_active,
sm->PTK.tk, klen, KEY_TYPE_PAIRWISE))
return;
@@ -2891,6 +2891,10 @@ static int wpa_ft_process_auth_req(struct wpa_state_machine *sm,
wpa_printf(MSG_DEBUG, "FT: Failed to parse FT IEs");
return WLAN_STATUS_UNSPECIFIED_FAILURE;
}
+
+ if (handle_extended_key_id(sm, parse.capabilities))
+ return WLAN_STATUS_UNSPECIFIED_FAILURE;
+
use_sha384 = wpa_key_mgmt_sha384(parse.key_mgmt);
pmk_r1_len = use_sha384 ? SHA384_MAC_LEN : PMK_LEN;
@@ -39,6 +39,7 @@ static void hostapd_wpa_auth_conf(struct hostapd_bss_config *conf,
{
os_memset(wconf, 0, sizeof(*wconf));
wconf->wpa = conf->wpa;
+ wconf->wpa_extended_key_id = conf->wpa_extended_key_id;
wconf->wpa_key_mgmt = conf->wpa_key_mgmt;
wconf->wpa_pairwise = conf->wpa_pairwise;
wconf->wpa_group = conf->wpa_group;
@@ -369,7 +370,12 @@ static int hostapd_wpa_auth_set_key(void *ctx, int vlan_id, enum wpa_alg alg,
}
#ifdef CONFIG_TESTING_OPTIONS
- if (addr && !is_broadcast_ether_addr(addr)) {
+ if (key_type == KEY_TYPE_SET_TX) {
+ /* KEY_TYPE_NO_AUTO_TX installed the key and updated the
+ * variables. Since KEY_TYPE_SET_TX would overwrite the
+ * desired information with zeros do nothing.
+ */
+ } else if (addr && !is_broadcast_ether_addr(addr)) {
struct sta_info *sta;
sta = ap_get_sta(hapd, addr);
@@ -1305,6 +1311,30 @@ int hostapd_setup_wpa(struct hostapd_data *hapd)
_conf.tx_status = 1;
if (hapd->iface->drv_flags & WPA_DRIVER_FLAGS_AP_MLME)
_conf.ap_mlme = 1;
+
+ if (_conf.wpa_extended_key_id) {
+ if (_conf.wpa & WPA_PROTO_RSN &&
+ _conf.rsn_pairwise & (WPA_CIPHER_CCMP | WPA_CIPHER_GCMP |
+ WPA_CIPHER_GCMP_256 |
+ WPA_CIPHER_CCMP_256) &&
+ hapd->iface->drv_flags & WPA_DRIVER_FLAGS_EXTENDED_KEY_ID) {
+ wpa_msg(hapd->msg_ctx, MSG_INFO,
+ "Enable Extended Key ID support");
+ } else {
+ if (!(hapd->iface->drv_flags &
+ WPA_DRIVER_FLAGS_EXTENDED_KEY_ID))
+ wpa_msg(hapd->msg_ctx, MSG_INFO,
+ "Extended Key ID not supported by driver");
+ else
+ wpa_msg(hapd->msg_ctx, MSG_INFO,
+ "Extended Key ID requires wpa2 and CCMP/GCMP");
+ _conf.wpa_extended_key_id = 0;
+ }
+ } else if (_conf.wpa & WPA_PROTO_RSN) {
+ wpa_msg(hapd->msg_ctx, MSG_INFO,
+ "Extended Key ID support disabled");
+ }
+
hapd->wpa_auth = wpa_init(hapd->own_addr, &_conf, &cb, hapd);
if (hapd->wpa_auth == NULL) {
wpa_printf(MSG_ERROR, "WPA initialization failed.");
@@ -61,6 +61,8 @@ struct wpa_state_machine {
unsigned int pmk_len;
u8 pmkid[PMKID_LEN]; /* valid if pmkid_set == 1 */
struct wpa_ptk PTK;
+ u8 keyidx_active;
+ Boolean use_extended_key_id;
Boolean PTK_valid;
Boolean pairwise_set;
Boolean tk_already_set;
@@ -284,6 +286,7 @@ int wpa_auth_for_each_sta(struct wpa_authenticator *wpa_auth,
int wpa_auth_for_each_auth(struct wpa_authenticator *wpa_auth,
int (*cb)(struct wpa_authenticator *a, void *ctx),
void *cb_ctx);
+int handle_extended_key_id(struct wpa_state_machine *sm, int capabilities);
#ifdef CONFIG_IEEE80211R_AP
int wpa_write_mdie(struct wpa_auth_config *conf, u8 *buf, size_t len);
@@ -286,6 +286,8 @@ int wpa_write_rsn_ie(struct wpa_auth_config *conf, u8 *buf, size_t len,
/* 4 PTKSA replay counters when using WMM */
capab |= (RSN_NUM_REPLAY_COUNTERS_16 << 2);
}
+ if (conf->wpa_extended_key_id)
+ capab |= WPA_CAPABILITY_EXT_KEY_ID_FOR_UNICAST;
#ifdef CONFIG_IEEE80211W
if (conf->ieee80211w != NO_MGMT_FRAME_PROTECTION) {
capab |= WPA_CAPABILITY_MFPC;
@@ -411,6 +413,8 @@ static u8 * wpa_write_osen(struct wpa_auth_config *conf, u8 *eid)
/* 4 PTKSA replay counters when using WMM */
capab |= (RSN_NUM_REPLAY_COUNTERS_16 << 2);
}
+ if (conf->wpa_extended_key_id)
+ capab |= WPA_CAPABILITY_EXT_KEY_ID_FOR_UNICAST;
#ifdef CONFIG_IEEE80211W
if (conf->ieee80211w != NO_MGMT_FRAME_PROTECTION) {
capab |= WPA_CAPABILITY_MFPC;
@@ -435,8 +439,9 @@ int wpa_auth_gen_wpa_ie(struct wpa_authenticator *wpa_auth)
{
u8 *pos, buf[128];
int res;
-
#ifdef CONFIG_TESTING_OPTIONS
+ struct wpa_ie_data data;
+
if (wpa_auth->conf.own_ie_override_len) {
wpa_hexdump(MSG_DEBUG, "WPA: Forced own IE(s) for testing",
wpa_auth->conf.own_ie_override,
@@ -449,6 +454,14 @@ int wpa_auth_gen_wpa_ie(struct wpa_authenticator *wpa_auth)
os_memcpy(wpa_auth->wpa_ie, wpa_auth->conf.own_ie_override,
wpa_auth->conf.own_ie_override_len);
wpa_auth->wpa_ie_len = wpa_auth->conf.own_ie_override_len;
+ if (wpa_parse_wpa_ie_rsn(wpa_auth->wpa_ie,
+ wpa_auth->wpa_ie_len, &data) ||
+ !(data.capabilities &
+ WPA_CAPABILITY_EXT_KEY_ID_FOR_UNICAST)) {
+ wpa_printf(MSG_DEBUG,
+ "WPA: Own IE forcing wpa_extended_key_id=0");
+ wpa_auth->conf.wpa_extended_key_id = 0;
+ }
return 0;
}
#endif /* CONFIG_TESTING_OPTIONS */
@@ -528,6 +541,31 @@ static int wpa_auth_okc_iter(struct wpa_authenticator *a, void *ctx)
return 0;
}
+int handle_extended_key_id(struct wpa_state_machine *sm, int capabilities)
+{
+ struct wpa_auth_config *conf = &sm->wpa_auth->conf;
+
+ if (conf->wpa_extended_key_id &&
+ capabilities & WPA_CAPABILITY_EXT_KEY_ID_FOR_UNICAST) {
+ if (!sm->use_extended_key_id && sm->pairwise_set) {
+ wpa_printf(MSG_DEBUG,
+ "Can only enable Extended Key ID on initial connect");
+ return -1;
+ } else if (!sm->use_extended_key_id) {
+ sm->use_extended_key_id = TRUE;
+ }
+ } else {
+ if (sm->use_extended_key_id && sm->pairwise_set) {
+ wpa_printf(MSG_DEBUG,
+ "Already using Extended Key ID, can't stop");
+ return -1;
+ } else if (sm->use_extended_key_id) {
+ sm->use_extended_key_id = FALSE;
+ sm->keyidx_active = 0;
+ }
+ }
+ return 0;
+}
int wpa_validate_wpa_ie(struct wpa_authenticator *wpa_auth,
struct wpa_state_machine *sm, int freq,
@@ -809,6 +847,8 @@ int wpa_validate_wpa_ie(struct wpa_authenticator *wpa_auth,
}
#endif /* CONFIG_IEEE80211W */
+ if (handle_extended_key_id(sm, data.capabilities))
+ return WPA_INVALID_IE;
#ifdef CONFIG_IEEE80211R_AP
if (wpa_key_mgmt_ft(sm->wpa_key_mgmt)) {
if (mdie == NULL || mdie_len < MOBILITY_DOMAIN_ID_LEN + 1) {
@@ -963,6 +963,7 @@ int wpa_ft_parse_ies(const u8 *ies, size_t ies_len,
parse->rsn_pmkid = data.pmkid;
parse->key_mgmt = data.key_mgmt;
parse->pairwise_cipher = data.pairwise_cipher;
+ parse->capabilities = data.capabilities;
if (update_use_sha384) {
use_sha384 =
wpa_key_mgmt_sha384(parse->key_mgmt);
@@ -475,6 +475,7 @@ struct wpa_ft_ies {
size_t ric_len;
int key_mgmt;
int pairwise_cipher;
+ int capabilities;
};
int wpa_ft_parse_ies(const u8 *ies, size_t ies_len, struct wpa_ft_ies *parse,
Add support for Extended Key ID in hostapd based on IEEE 802.11 - 2016. Extended Key ID allows to rekey PTK keys without the otherwise unavoidable MPDU losses on a busy link. The standard is fully backward compatible, allowing an AP to server STA's with and without support for it. Signed-off-by: Alexander Wetzel <alexander@wetzel-home.de> --- This is now finally starting the real work on the Extended Key ID support. Most is directly based on IEEE 802.11 - 2016 or an obvious consequence. But the sanity checks for Extended Key ID and how we handle FT with it are not. A Extended Key ID capable AP will have two different keys using keyid 1: The "usual" broadcast key and a second unicast key. (We already had a quick mail exchange about that, see https://marc.info/?l=linux-wireless&m=154427921122092&w=2) It's fully backward compatible and can serve client supporting Extended Key ID and not at the same time. I can't find any reference how we should handle FT combined with Extended Key ID. While our beacons announce Extended Key ID support a "normal" FT handshake never has a 4-way EAPOL handshake and thus there is no documented way to hand over the KeyID. We could of course then just agree to use the keyid 0 and to really start to use Extended Key ID with the first rekey. But I prefer to just also hand over the KeyID in addition to the GTK Key ID: This allows us to also use the keyid 1 with the initial key and open the door to verify if a remote STA is indeed able to use Extended Key ID and either fail at the initial connect or even fall back when not. (More about that in the last patch of the series.) hostapd/config_file.c | 2 ++ hostapd/hostapd.conf | 10 ++++++ src/ap/ap_config.c | 1 + src/ap/ap_config.h | 1 + src/ap/hs20.c | 2 ++ src/ap/wpa_auth.c | 71 ++++++++++++++++++++++++++++++++++++----- src/ap/wpa_auth.h | 1 + src/ap/wpa_auth_ft.c | 6 +++- src/ap/wpa_auth_glue.c | 32 ++++++++++++++++++- src/ap/wpa_auth_i.h | 3 ++ src/ap/wpa_auth_ie.c | 42 +++++++++++++++++++++++- src/common/wpa_common.c | 1 + src/common/wpa_common.h | 1 + 13 files changed, 162 insertions(+), 11 deletions(-)