| The WPA2 four-way handshake protocol is vulnerable to replay attacks which can |
| result in unauthenticated clients gaining access to the network. |
| |
| Backport a number of patches from upstream to fix this. |
| |
| CVE: CVE-2017-13077 |
| CVE: CVE-2017-13078 |
| CVE: CVE-2017-13079 |
| CVE: CVE-2017-13080 |
| CVE: CVE-2017-13081 |
| CVE: CVE-2017-13082 |
| CVE: CVE-2017-13086 |
| CVE: CVE-2017-13087 |
| CVE: CVE-2017-13088 |
| |
| Upstream-Status: Backport |
| Signed-off-by: Ross Burton <ross.burton@intel.com> |
| |
| From cf4cab804c7afd5c45505528a8d16e46163243a2 Mon Sep 17 00:00:00 2001 |
| From: Mathy Vanhoef <Mathy.Vanhoef@cs.kuleuven.be> |
| Date: Fri, 14 Jul 2017 15:15:35 +0200 |
| Subject: [PATCH 1/8] hostapd: Avoid key reinstallation in FT handshake |
| |
| Do not reinstall TK to the driver during Reassociation Response frame |
| processing if the first attempt of setting the TK succeeded. This avoids |
| issues related to clearing the TX/RX PN that could result in reusing |
| same PN values for transmitted frames (e.g., due to CCM nonce reuse and |
| also hitting replay protection on the receiver) and accepting replayed |
| frames on RX side. |
| |
| This issue was introduced by the commit |
| 0e84c25434e6a1f283c7b4e62e483729085b78d2 ('FT: Fix PTK configuration in |
| authenticator') which allowed wpa_ft_install_ptk() to be called multiple |
| times with the same PTK. While the second configuration attempt is |
| needed with some drivers, it must be done only if the first attempt |
| failed. |
| |
| Signed-off-by: Mathy Vanhoef <Mathy.Vanhoef@cs.kuleuven.be> |
| --- |
| src/ap/ieee802_11.c | 16 +++++++++++++--- |
| src/ap/wpa_auth.c | 11 +++++++++++ |
| src/ap/wpa_auth.h | 3 ++- |
| src/ap/wpa_auth_ft.c | 10 ++++++++++ |
| src/ap/wpa_auth_i.h | 1 + |
| 5 files changed, 37 insertions(+), 4 deletions(-) |
| |
| diff --git a/src/ap/ieee802_11.c b/src/ap/ieee802_11.c |
| index 4e04169..333035f 100644 |
| --- a/src/ap/ieee802_11.c |
| +++ b/src/ap/ieee802_11.c |
| @@ -1841,6 +1841,7 @@ static int add_associated_sta(struct hostapd_data *hapd, |
| { |
| struct ieee80211_ht_capabilities ht_cap; |
| struct ieee80211_vht_capabilities vht_cap; |
| + int set = 1; |
| |
| /* |
| * Remove the STA entry to ensure the STA PS state gets cleared and |
| @@ -1848,9 +1849,18 @@ static int add_associated_sta(struct hostapd_data *hapd, |
| * FT-over-the-DS, where a station re-associates back to the same AP but |
| * skips the authentication flow, or if working with a driver that |
| * does not support full AP client state. |
| + * |
| + * Skip this if the STA has already completed FT reassociation and the |
| + * TK has been configured since the TX/RX PN must not be reset to 0 for |
| + * the same key. |
| */ |
| - if (!sta->added_unassoc) |
| + if (!sta->added_unassoc && |
| + (!(sta->flags & WLAN_STA_AUTHORIZED) || |
| + !wpa_auth_sta_ft_tk_already_set(sta->wpa_sm))) { |
| hostapd_drv_sta_remove(hapd, sta->addr); |
| + wpa_auth_sm_event(sta->wpa_sm, WPA_DRV_STA_REMOVED); |
| + set = 0; |
| + } |
| |
| #ifdef CONFIG_IEEE80211N |
| if (sta->flags & WLAN_STA_HT) |
| @@ -1873,11 +1883,11 @@ static int add_associated_sta(struct hostapd_data *hapd, |
| sta->flags & WLAN_STA_VHT ? &vht_cap : NULL, |
| sta->flags | WLAN_STA_ASSOC, sta->qosinfo, |
| sta->vht_opmode, sta->p2p_ie ? 1 : 0, |
| - sta->added_unassoc)) { |
| + set)) { |
| hostapd_logger(hapd, sta->addr, |
| HOSTAPD_MODULE_IEEE80211, HOSTAPD_LEVEL_NOTICE, |
| "Could not %s STA to kernel driver", |
| - sta->added_unassoc ? "set" : "add"); |
| + set ? "set" : "add"); |
| |
| if (sta->added_unassoc) { |
| hostapd_drv_sta_remove(hapd, sta->addr); |
| diff --git a/src/ap/wpa_auth.c b/src/ap/wpa_auth.c |
| index 3587086..707971d 100644 |
| --- a/src/ap/wpa_auth.c |
| +++ b/src/ap/wpa_auth.c |
| @@ -1745,6 +1745,9 @@ int wpa_auth_sm_event(struct wpa_state_machine *sm, enum wpa_event event) |
| #else /* CONFIG_IEEE80211R */ |
| break; |
| #endif /* CONFIG_IEEE80211R */ |
| + case WPA_DRV_STA_REMOVED: |
| + sm->tk_already_set = FALSE; |
| + return 0; |
| } |
| |
| #ifdef CONFIG_IEEE80211R |
| @@ -3250,6 +3253,14 @@ int wpa_auth_sta_wpa_version(struct wpa_state_machine *sm) |
| } |
| |
| |
| +int wpa_auth_sta_ft_tk_already_set(struct wpa_state_machine *sm) |
| +{ |
| + if (!sm || !wpa_key_mgmt_ft(sm->wpa_key_mgmt)) |
| + return 0; |
| + return sm->tk_already_set; |
| +} |
| + |
| + |
| int wpa_auth_sta_clear_pmksa(struct wpa_state_machine *sm, |
| struct rsn_pmksa_cache_entry *entry) |
| { |
| diff --git a/src/ap/wpa_auth.h b/src/ap/wpa_auth.h |
| index 0de8d97..97461b0 100644 |
| --- a/src/ap/wpa_auth.h |
| +++ b/src/ap/wpa_auth.h |
| @@ -267,7 +267,7 @@ void wpa_receive(struct wpa_authenticator *wpa_auth, |
| u8 *data, size_t data_len); |
| enum wpa_event { |
| WPA_AUTH, WPA_ASSOC, WPA_DISASSOC, WPA_DEAUTH, WPA_REAUTH, |
| - WPA_REAUTH_EAPOL, WPA_ASSOC_FT |
| + WPA_REAUTH_EAPOL, WPA_ASSOC_FT, WPA_DRV_STA_REMOVED |
| }; |
| void wpa_remove_ptk(struct wpa_state_machine *sm); |
| int wpa_auth_sm_event(struct wpa_state_machine *sm, enum wpa_event event); |
| @@ -280,6 +280,7 @@ int wpa_auth_pairwise_set(struct wpa_state_machine *sm); |
| int wpa_auth_get_pairwise(struct wpa_state_machine *sm); |
| int wpa_auth_sta_key_mgmt(struct wpa_state_machine *sm); |
| int wpa_auth_sta_wpa_version(struct wpa_state_machine *sm); |
| +int wpa_auth_sta_ft_tk_already_set(struct wpa_state_machine *sm); |
| int wpa_auth_sta_clear_pmksa(struct wpa_state_machine *sm, |
| struct rsn_pmksa_cache_entry *entry); |
| struct rsn_pmksa_cache_entry * |
| diff --git a/src/ap/wpa_auth_ft.c b/src/ap/wpa_auth_ft.c |
| index 42242a5..e63b99a 100644 |
| --- a/src/ap/wpa_auth_ft.c |
| +++ b/src/ap/wpa_auth_ft.c |
| @@ -780,6 +780,14 @@ void wpa_ft_install_ptk(struct wpa_state_machine *sm) |
| return; |
| } |
| |
| + if (sm->tk_already_set) { |
| + /* Must avoid TK reconfiguration to prevent clearing of TX/RX |
| + * PN in the driver */ |
| + wpa_printf(MSG_DEBUG, |
| + "FT: Do not re-install same PTK to the driver"); |
| + return; |
| + } |
| + |
| /* FIX: add STA entry to kernel/driver here? The set_key will fail |
| * most likely without this.. At the moment, STA entry is added only |
| * after association has been completed. This function will be called |
| @@ -792,6 +800,7 @@ void wpa_ft_install_ptk(struct wpa_state_machine *sm) |
| |
| /* FIX: MLME-SetProtection.Request(TA, Tx_Rx) */ |
| sm->pairwise_set = TRUE; |
| + sm->tk_already_set = TRUE; |
| } |
| |
| |
| @@ -898,6 +907,7 @@ static int wpa_ft_process_auth_req(struct wpa_state_machine *sm, |
| |
| sm->pairwise = pairwise; |
| sm->PTK_valid = TRUE; |
| + sm->tk_already_set = FALSE; |
| wpa_ft_install_ptk(sm); |
| |
| buflen = 2 + sizeof(struct rsn_mdie) + 2 + sizeof(struct rsn_ftie) + |
| diff --git a/src/ap/wpa_auth_i.h b/src/ap/wpa_auth_i.h |
| index 72b7eb3..7fd8f05 100644 |
| --- a/src/ap/wpa_auth_i.h |
| +++ b/src/ap/wpa_auth_i.h |
| @@ -65,6 +65,7 @@ struct wpa_state_machine { |
| struct wpa_ptk PTK; |
| Boolean PTK_valid; |
| Boolean pairwise_set; |
| + Boolean tk_already_set; |
| int keycount; |
| Boolean Pair; |
| struct wpa_key_replay_counter { |
| -- |
| 2.7.4 |