Differential D2878 Diff 7063 files/0004-Prevent-installation-of-an-all-zero-TK.patch

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files/0004-Prevent-installation-of-an-all-zero-TK.patch

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				From 8f82bc94e8697a9d47fa8774dfdaaede1084912c Mon Sep 17 00:00:00 2001
				From: Mathy Vanhoef <Mathy.Vanhoef@cs.kuleuven.be>
				Date: Fri, 29 Sep 2017 04:22:51 +0200
				Subject: [PATCH 4/8] Prevent installation of an all-zero TK

				Properly track whether a PTK has already been installed to the driver
				and the TK part cleared from memory. This prevents an attacker from
				trying to trick the client into installing an all-zero TK.

				This fixes the earlier fix in commit
				ad00d64e7d8827b3cebd665a0ceb08adabf15e1e ('Fix TK configuration to the
				driver in EAPOL-Key 3/4 retry case') which did not take into account
				possibility of an extra message 1/4 showing up between retries of
				message 3/4.

				Signed-off-by: Mathy Vanhoef <Mathy.Vanhoef@cs.kuleuven.be>
				---
				src/common/wpa_common.h \| 1 +
				src/rsn_supp/wpa.c \| 5 ++---
				src/rsn_supp/wpa_i.h \| 1 -
				3 files changed, 3 insertions(+), 4 deletions(-)

				diff --git a/src/common/wpa_common.h b/src/common/wpa_common.h
				index d200285..1021ccb 100644
				--- a/src/common/wpa_common.h
				+++ b/src/common/wpa_common.h
				@@ -215,6 +215,7 @@ struct wpa_ptk {
				size_t kck_len;
				size_t kek_len;
				size_t tk_len;
				+ int installed; /* 1 if key has already been installed to driver */
				};

				struct wpa_gtk {
				diff --git a/src/rsn_supp/wpa.c b/src/rsn_supp/wpa.c
				index 7a2c68d..0550a41 100644
				--- a/src/rsn_supp/wpa.c
				+++ b/src/rsn_supp/wpa.c
				@@ -510,7 +510,6 @@ static void wpa_supplicant_process_1_of_4(struct wpa_sm *sm,
				os_memset(buf, 0, sizeof(buf));
				}
				sm->tptk_set = 1;
				- sm->tk_to_set = 1;

				kde = sm->assoc_wpa_ie;
				kde_len = sm->assoc_wpa_ie_len;
				@@ -615,7 +614,7 @@ static int wpa_supplicant_install_ptk(struct wpa_sm *sm,
				enum wpa_alg alg;
				const u8 *key_rsc;

				- if (!sm->tk_to_set) {
				+ if (sm->ptk.installed) {
				wpa_dbg(sm->ctx->msg_ctx, MSG_DEBUG,
				"WPA: Do not re-install same PTK to the driver");
				return 0;
				@@ -659,7 +658,7 @@ static int wpa_supplicant_install_ptk(struct wpa_sm *sm,

				/* TK is not needed anymore in supplicant */
				os_memset(sm->ptk.tk, 0, WPA_TK_MAX_LEN);
				- sm->tk_to_set = 0;
				+ sm->ptk.installed = 1;

				if (sm->wpa_ptk_rekey) {
				eloop_cancel_timeout(wpa_sm_rekey_ptk, sm, NULL);
				diff --git a/src/rsn_supp/wpa_i.h b/src/rsn_supp/wpa_i.h
				index 9a54631..41f371f 100644
				--- a/src/rsn_supp/wpa_i.h
				+++ b/src/rsn_supp/wpa_i.h
				@@ -24,7 +24,6 @@ struct wpa_sm {
				struct wpa_ptk ptk, tptk;
				int ptk_set, tptk_set;
				unsigned int msg_3_of_4_ok:1;
				- unsigned int tk_to_set:1;
				u8 snonce[WPA_NONCE_LEN];
				u8 anonce[WPA_NONCE_LEN]; /* ANonce from the last 1/4 msg */
				int renew_snonce;
				--
				2.7.4