1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
|
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
|
