TDLS: Reject TPK-TK reconfiguration
am: 4c52740a9b
Change-Id: Ia2221f776ade171d76c14caf8a8ecd303140754e
diff --git a/src/rsn_supp/tdls.c b/src/rsn_supp/tdls.c
index 73a1432..e814b45 100644
--- a/src/rsn_supp/tdls.c
+++ b/src/rsn_supp/tdls.c
@@ -111,6 +111,7 @@
u8 tk[16]; /* TPK-TK; assuming only CCMP will be used */
} tpk;
int tpk_set;
+ int tk_set; /* TPK-TK configured to the driver */
int tpk_success;
int tpk_in_progress;
@@ -188,6 +189,20 @@
u8 rsc[6];
enum wpa_alg alg;
+ if (peer->tk_set) {
+ /*
+ * This same TPK-TK has already been configured to the driver
+ * and this new configuration attempt (likely due to an
+ * unexpected retransmitted frame) would result in clearing
+ * the TX/RX sequence number which can break security, so must
+ * not allow that to happen.
+ */
+ wpa_printf(MSG_INFO, "TDLS: TPK-TK for the peer " MACSTR
+ " has already been configured to the driver - do not reconfigure",
+ MAC2STR(peer->addr));
+ return -1;
+ }
+
os_memset(rsc, 0, 6);
switch (peer->cipher) {
@@ -205,12 +220,15 @@
return -1;
}
+ wpa_printf(MSG_DEBUG, "TDLS: Configure pairwise key for peer " MACSTR,
+ MAC2STR(peer->addr));
if (wpa_sm_set_key(sm, alg, peer->addr, -1, 1,
rsc, sizeof(rsc), peer->tpk.tk, key_len) < 0) {
wpa_printf(MSG_WARNING, "TDLS: Failed to set TPK to the "
"driver");
return -1;
}
+ peer->tk_set = 1;
return 0;
}
@@ -686,7 +704,7 @@
peer->cipher = 0;
peer->qos_info = 0;
peer->wmm_capable = 0;
- peer->tpk_set = peer->tpk_success = 0;
+ peer->tk_set = peer->tpk_set = peer->tpk_success = 0;
os_memset(&peer->tpk, 0, sizeof(peer->tpk));
os_memset(peer->inonce, 0, WPA_NONCE_LEN);
os_memset(peer->rnonce, 0, WPA_NONCE_LEN);
@@ -1134,6 +1152,7 @@
wpa_tdls_peer_free(sm, peer);
return -1;
}
+ peer->tk_set = 0; /* A new nonce results in a new TK */
wpa_hexdump(MSG_DEBUG, "TDLS: Initiator Nonce for TPK handshake",
peer->inonce, WPA_NONCE_LEN);
os_memcpy(ftie->Snonce, peer->inonce, WPA_NONCE_LEN);
@@ -1730,6 +1749,19 @@
}
+static int tdls_nonce_set(const u8 *nonce)
+{
+ int i;
+
+ for (i = 0; i < WPA_NONCE_LEN; i++) {
+ if (nonce[i])
+ return 1;
+ }
+
+ return 0;
+}
+
+
static int wpa_tdls_process_tpk_m1(struct wpa_sm *sm, const u8 *src_addr,
const u8 *buf, size_t len)
{
@@ -1978,7 +2010,8 @@
peer->rsnie_i_len = kde.rsn_ie_len;
peer->cipher = cipher;
- if (os_memcmp(peer->inonce, ftie->Snonce, WPA_NONCE_LEN) != 0) {
+ if (os_memcmp(peer->inonce, ftie->Snonce, WPA_NONCE_LEN) != 0 ||
+ !tdls_nonce_set(peer->inonce)) {
/*
* There is no point in updating the RNonce for every obtained
* TPK M1 frame (e.g., retransmission due to timeout) with the
@@ -1994,6 +2027,7 @@
"TDLS: Failed to get random data for responder nonce");
goto error;
}
+ peer->tk_set = 0; /* A new nonce results in a new TK */
}
#if 0