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.
Bug: 65245581
Test: Wifi Integration suite
Merged-In: If3e736da9a822635551b72074e8f7c3f4d921e87
Change-Id: If3e736da9a822635551b72074e8f7c3f4d921e87
Signed-off-by: Mathy Vanhoef <Mathy.Vanhoef@cs.kuleuven.be>
Signed-off-by: Glen Kuhne <kuh@google.com>
(cherry picked from commit 5ad4a6a4d1a0fc47e6b870436e10d381971ad205)
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 @@
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 95bd7be..0d2b0aa 100644
--- a/src/rsn_supp/wpa.c
+++ b/src/rsn_supp/wpa.c
@@ -510,7 +510,6 @@
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 @@
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 @@
/* 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 afc9e37..2d32e46 100644
--- a/src/rsn_supp/wpa_i.h
+++ b/src/rsn_supp/wpa_i.h
@@ -24,7 +24,6 @@
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;
