Fix TK configuration to the driver in EAPOL-Key 3/4 retry case

Commit 7d711541dced759b34313477d5d163e65c5b0131 ('Clear TK part of PTK
after driver key configuration') started clearing TK from memory
immediately after having configured it to the driver when processing
EAPOL-Key message 3/4. While this covered the most common case, it did
not take into account the possibility of the authenticator having to
retry EAPOL-Key message 3/4 in case the first EAPOL-Key message 4/4
response is lost. That case ended up trying to reinstall the same TK to
the driver, but the key was not available anymore.

Fix the EAPOL-Key message 3/4 retry case by configuring TK to the driver
only once. There was no need to try to set the same key after each
EAPOL-Key message 3/4 since TK could not change. If actual PTK rekeying
is used, the new TK will be configured once when processing the new
EAPOL-Key message 3/4 for the first time.

Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>

src/rsn_supp/wpa.c

@@ -500,6 +500,7 @@ 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;
@@ -605,6 +606,12 @@ static int wpa_supplicant_install_ptk(struct wpa_sm *sm,
 	const u8 *key_rsc;
 	u8 null_rsc[8] = { 0, 0, 0, 0, 0, 0, 0, 0 };
 
+	if (!sm->tk_to_set) {
+		wpa_dbg(sm->ctx->msg_ctx, MSG_DEBUG,
+			"WPA: Do not re-install same PTK to the driver");
+		return 0;
+	}
+
 	wpa_dbg(sm->ctx->msg_ctx, MSG_DEBUG,
 		"WPA: Installing PTK to the driver");
 
@@ -643,6 +650,7 @@ 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;
 
 	if (sm->wpa_ptk_rekey) {
 		eloop_cancel_timeout(wpa_sm_rekey_ptk, sm, NULL);

src/rsn_supp/wpa_i.h

@@ -24,6 +24,7 @@ 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;