Contents of /trunk/wpa_supplicant/patches/0001-hostapd-Avoid-key-reinstallation-in-FT-handshake.patch
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Tue Oct 17 10:55:21 2017 UTC (6 years, 11 months ago) by niro
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Tue Oct 17 10:55:21 2017 UTC (6 years, 11 months ago) by niro
File size: 6218 byte(s)
-krackattack patches
1 | From cf4cab804c7afd5c45505528a8d16e46163243a2 Mon Sep 17 00:00:00 2001 |
2 | From: Mathy Vanhoef <Mathy.Vanhoef@cs.kuleuven.be> |
3 | Date: Fri, 14 Jul 2017 15:15:35 +0200 |
4 | Subject: [PATCH 1/8] hostapd: Avoid key reinstallation in FT handshake |
5 | |
6 | Do not reinstall TK to the driver during Reassociation Response frame |
7 | processing if the first attempt of setting the TK succeeded. This avoids |
8 | issues related to clearing the TX/RX PN that could result in reusing |
9 | same PN values for transmitted frames (e.g., due to CCM nonce reuse and |
10 | also hitting replay protection on the receiver) and accepting replayed |
11 | frames on RX side. |
12 | |
13 | This issue was introduced by the commit |
14 | 0e84c25434e6a1f283c7b4e62e483729085b78d2 ('FT: Fix PTK configuration in |
15 | authenticator') which allowed wpa_ft_install_ptk() to be called multiple |
16 | times with the same PTK. While the second configuration attempt is |
17 | needed with some drivers, it must be done only if the first attempt |
18 | failed. |
19 | |
20 | Signed-off-by: Mathy Vanhoef <Mathy.Vanhoef@cs.kuleuven.be> |
21 | --- |
22 | src/ap/ieee802_11.c | 16 +++++++++++++--- |
23 | src/ap/wpa_auth.c | 11 +++++++++++ |
24 | src/ap/wpa_auth.h | 3 ++- |
25 | src/ap/wpa_auth_ft.c | 10 ++++++++++ |
26 | src/ap/wpa_auth_i.h | 1 + |
27 | 5 files changed, 37 insertions(+), 4 deletions(-) |
28 | |
29 | diff --git a/src/ap/ieee802_11.c b/src/ap/ieee802_11.c |
30 | index 4e04169..333035f 100644 |
31 | --- a/src/ap/ieee802_11.c |
32 | +++ b/src/ap/ieee802_11.c |
33 | @@ -1841,6 +1841,7 @@ static int add_associated_sta(struct hostapd_data *hapd, |
34 | { |
35 | struct ieee80211_ht_capabilities ht_cap; |
36 | struct ieee80211_vht_capabilities vht_cap; |
37 | + int set = 1; |
38 | |
39 | /* |
40 | * Remove the STA entry to ensure the STA PS state gets cleared and |
41 | @@ -1848,9 +1849,18 @@ static int add_associated_sta(struct hostapd_data *hapd, |
42 | * FT-over-the-DS, where a station re-associates back to the same AP but |
43 | * skips the authentication flow, or if working with a driver that |
44 | * does not support full AP client state. |
45 | + * |
46 | + * Skip this if the STA has already completed FT reassociation and the |
47 | + * TK has been configured since the TX/RX PN must not be reset to 0 for |
48 | + * the same key. |
49 | */ |
50 | - if (!sta->added_unassoc) |
51 | + if (!sta->added_unassoc && |
52 | + (!(sta->flags & WLAN_STA_AUTHORIZED) || |
53 | + !wpa_auth_sta_ft_tk_already_set(sta->wpa_sm))) { |
54 | hostapd_drv_sta_remove(hapd, sta->addr); |
55 | + wpa_auth_sm_event(sta->wpa_sm, WPA_DRV_STA_REMOVED); |
56 | + set = 0; |
57 | + } |
58 | |
59 | #ifdef CONFIG_IEEE80211N |
60 | if (sta->flags & WLAN_STA_HT) |
61 | @@ -1873,11 +1883,11 @@ static int add_associated_sta(struct hostapd_data *hapd, |
62 | sta->flags & WLAN_STA_VHT ? &vht_cap : NULL, |
63 | sta->flags | WLAN_STA_ASSOC, sta->qosinfo, |
64 | sta->vht_opmode, sta->p2p_ie ? 1 : 0, |
65 | - sta->added_unassoc)) { |
66 | + set)) { |
67 | hostapd_logger(hapd, sta->addr, |
68 | HOSTAPD_MODULE_IEEE80211, HOSTAPD_LEVEL_NOTICE, |
69 | "Could not %s STA to kernel driver", |
70 | - sta->added_unassoc ? "set" : "add"); |
71 | + set ? "set" : "add"); |
72 | |
73 | if (sta->added_unassoc) { |
74 | hostapd_drv_sta_remove(hapd, sta->addr); |
75 | diff --git a/src/ap/wpa_auth.c b/src/ap/wpa_auth.c |
76 | index 3587086..707971d 100644 |
77 | --- a/src/ap/wpa_auth.c |
78 | +++ b/src/ap/wpa_auth.c |
79 | @@ -1745,6 +1745,9 @@ int wpa_auth_sm_event(struct wpa_state_machine *sm, enum wpa_event event) |
80 | #else /* CONFIG_IEEE80211R */ |
81 | break; |
82 | #endif /* CONFIG_IEEE80211R */ |
83 | + case WPA_DRV_STA_REMOVED: |
84 | + sm->tk_already_set = FALSE; |
85 | + return 0; |
86 | } |
87 | |
88 | #ifdef CONFIG_IEEE80211R |
89 | @@ -3250,6 +3253,14 @@ int wpa_auth_sta_wpa_version(struct wpa_state_machine *sm) |
90 | } |
91 | |
92 | |
93 | +int wpa_auth_sta_ft_tk_already_set(struct wpa_state_machine *sm) |
94 | +{ |
95 | + if (!sm || !wpa_key_mgmt_ft(sm->wpa_key_mgmt)) |
96 | + return 0; |
97 | + return sm->tk_already_set; |
98 | +} |
99 | + |
100 | + |
101 | int wpa_auth_sta_clear_pmksa(struct wpa_state_machine *sm, |
102 | struct rsn_pmksa_cache_entry *entry) |
103 | { |
104 | diff --git a/src/ap/wpa_auth.h b/src/ap/wpa_auth.h |
105 | index 0de8d97..97461b0 100644 |
106 | --- a/src/ap/wpa_auth.h |
107 | +++ b/src/ap/wpa_auth.h |
108 | @@ -267,7 +267,7 @@ void wpa_receive(struct wpa_authenticator *wpa_auth, |
109 | u8 *data, size_t data_len); |
110 | enum wpa_event { |
111 | WPA_AUTH, WPA_ASSOC, WPA_DISASSOC, WPA_DEAUTH, WPA_REAUTH, |
112 | - WPA_REAUTH_EAPOL, WPA_ASSOC_FT |
113 | + WPA_REAUTH_EAPOL, WPA_ASSOC_FT, WPA_DRV_STA_REMOVED |
114 | }; |
115 | void wpa_remove_ptk(struct wpa_state_machine *sm); |
116 | int wpa_auth_sm_event(struct wpa_state_machine *sm, enum wpa_event event); |
117 | @@ -280,6 +280,7 @@ int wpa_auth_pairwise_set(struct wpa_state_machine *sm); |
118 | int wpa_auth_get_pairwise(struct wpa_state_machine *sm); |
119 | int wpa_auth_sta_key_mgmt(struct wpa_state_machine *sm); |
120 | int wpa_auth_sta_wpa_version(struct wpa_state_machine *sm); |
121 | +int wpa_auth_sta_ft_tk_already_set(struct wpa_state_machine *sm); |
122 | int wpa_auth_sta_clear_pmksa(struct wpa_state_machine *sm, |
123 | struct rsn_pmksa_cache_entry *entry); |
124 | struct rsn_pmksa_cache_entry * |
125 | diff --git a/src/ap/wpa_auth_ft.c b/src/ap/wpa_auth_ft.c |
126 | index 42242a5..e63b99a 100644 |
127 | --- a/src/ap/wpa_auth_ft.c |
128 | +++ b/src/ap/wpa_auth_ft.c |
129 | @@ -780,6 +780,14 @@ void wpa_ft_install_ptk(struct wpa_state_machine *sm) |
130 | return; |
131 | } |
132 | |
133 | + if (sm->tk_already_set) { |
134 | + /* Must avoid TK reconfiguration to prevent clearing of TX/RX |
135 | + * PN in the driver */ |
136 | + wpa_printf(MSG_DEBUG, |
137 | + "FT: Do not re-install same PTK to the driver"); |
138 | + return; |
139 | + } |
140 | + |
141 | /* FIX: add STA entry to kernel/driver here? The set_key will fail |
142 | * most likely without this.. At the moment, STA entry is added only |
143 | * after association has been completed. This function will be called |
144 | @@ -792,6 +800,7 @@ void wpa_ft_install_ptk(struct wpa_state_machine *sm) |
145 | |
146 | /* FIX: MLME-SetProtection.Request(TA, Tx_Rx) */ |
147 | sm->pairwise_set = TRUE; |
148 | + sm->tk_already_set = TRUE; |
149 | } |
150 | |
151 | |
152 | @@ -898,6 +907,7 @@ static int wpa_ft_process_auth_req(struct wpa_state_machine *sm, |
153 | |
154 | sm->pairwise = pairwise; |
155 | sm->PTK_valid = TRUE; |
156 | + sm->tk_already_set = FALSE; |
157 | wpa_ft_install_ptk(sm); |
158 | |
159 | buflen = 2 + sizeof(struct rsn_mdie) + 2 + sizeof(struct rsn_ftie) + |
160 | diff --git a/src/ap/wpa_auth_i.h b/src/ap/wpa_auth_i.h |
161 | index 72b7eb3..7fd8f05 100644 |
162 | --- a/src/ap/wpa_auth_i.h |
163 | +++ b/src/ap/wpa_auth_i.h |
164 | @@ -65,6 +65,7 @@ struct wpa_state_machine { |
165 | struct wpa_ptk PTK; |
166 | Boolean PTK_valid; |
167 | Boolean pairwise_set; |
168 | + Boolean tk_already_set; |
169 | int keycount; |
170 | Boolean Pair; |
171 | struct wpa_key_replay_counter { |
172 | -- |
173 | 2.7.4 |
174 |