--- /dev/null
+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
+
projects / 15.05 / openwrt.git / blobdiff