Added session message counter check to supplicant 4WH

Added check for message counter received on Message 1 to prevent
problems when Message 1 is replayed to supplicant by lower layers.
The PMK replay counter is not updated from Messsage 1 (which is
unsecure), so the counter is 4WH session specific only.

Author: Mika Leppänen

source/Security/protocols/fwh_sec_prot/supp_fwh_sec_prot.c

@@ -86,7 +86,7 @@ static int8_t supp_fwh_sec_prot_init(sec_prot_t *prot);
 static void supp_fwh_sec_prot_create_response(sec_prot_t *prot, sec_prot_result_e result);
 static void supp_fwh_sec_prot_delete(sec_prot_t *prot);
 static int8_t supp_fwh_sec_prot_receive(sec_prot_t *prot, void *pdu, uint16_t size);
-static fwh_sec_prot_msg_e supp_fwh_sec_prot_message_get(eapol_pdu_t *eapol_pdu, sec_prot_keys_t *sec_keys);
+static fwh_sec_prot_msg_e supp_fwh_sec_prot_message_get(sec_prot_t *prot, eapol_pdu_t *eapol_pdu);
 static void supp_fwh_sec_prot_state_machine(sec_prot_t *prot);
 
 static int8_t supp_fwh_sec_prot_message_send(sec_prot_t *prot, fwh_sec_prot_msg_e msg);
@@ -96,6 +96,7 @@ static int8_t supp_fwh_sec_prot_ptk_generate(sec_prot_t *prot, sec_prot_keys_t *
 static int8_t supp_fwh_sec_prot_mic_validate(sec_prot_t *prot);
 
 static void supp_fwh_sec_prot_recv_replay_counter_store(sec_prot_t *prot);
+static uint64_t supp_fwh_sec_prot_recv_replay_counter_get(sec_prot_t *prot);
 static void supp_fwh_sec_prot_anonce_store(sec_prot_t *prot);
 static int8_t supp_fwh_sec_prot_anonce_validate(sec_prot_t *prot);
 static void supp_fwh_sec_prot_security_replay_counter_update(sec_prot_t *prot);
@@ -137,6 +138,7 @@ static int8_t supp_fwh_sec_prot_init(sec_prot_t *prot)
 
     data->common.ticks = 30 * 10; // 30 seconds
     data->msg3_retry_wait = false;
+    data->recv_replay_cnt = 0;
 
     uint8_t eui64[8] = {0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08};
     sec_prot_lib_nonce_init(data->snonce, eui64, 1000);
@@ -167,7 +169,7 @@ static int8_t supp_fwh_sec_prot_receive(sec_prot_t *prot, void *pdu, uint16_t si
     // Decoding is successful
     if (eapol_parse_pdu_header(pdu, size, &data->recv_eapol_pdu)) {
         // Get message
-        data->recv_msg = supp_fwh_sec_prot_message_get(&data->recv_eapol_pdu, prot->sec_keys);
+        data->recv_msg = supp_fwh_sec_prot_message_get(prot, &data->recv_eapol_pdu);
         if (data->recv_msg != FWH_MESSAGE_UNKNOWN) {
             tr_info("4WH: recv %s", data->recv_msg == FWH_MESSAGE_1 ? "Message 1" : "Message 3");
 
@@ -191,7 +193,7 @@ static int8_t supp_fwh_sec_prot_receive(sec_prot_t *prot, void *pdu, uint16_t si
     return ret_val;
 }
 
-static fwh_sec_prot_msg_e supp_fwh_sec_prot_message_get(eapol_pdu_t *eapol_pdu, sec_prot_keys_t *sec_keys)
+static fwh_sec_prot_msg_e supp_fwh_sec_prot_message_get(sec_prot_t *prot, eapol_pdu_t *eapol_pdu)
 {
     fwh_sec_prot_msg_e msg = FWH_MESSAGE_UNKNOWN;
 
@@ -203,17 +205,23 @@ static fwh_sec_prot_msg_e supp_fwh_sec_prot_message_get(eapol_pdu_t *eapol_pdu,
     uint8_t key_mask = sec_prot_lib_key_mask_get(eapol_pdu);
 
     switch (key_mask) {
+        // Message 1
         case KEY_INFO_KEY_ACK:
-            // Must have valid replay counter
-            if (eapol_pdu->msg.key.replay_counter > sec_prot_keys_pmk_replay_cnt_get(sec_keys)) {
+            /* Must have valid replay counter, both larger for PMK and larger that is used on
+             * the four way handshake session (note: PMK replay counter is not updated for Message 1
+             * but session specific counter is)
+             */
+            if (eapol_pdu->msg.key.replay_counter > sec_prot_keys_pmk_replay_cnt_get(prot->sec_keys) &&
+                    eapol_pdu->msg.key.replay_counter > supp_fwh_sec_prot_recv_replay_counter_get(prot)) {
                 msg = FWH_MESSAGE_1;
             } else {
                 tr_error("4WH: invalid replay counter %"PRId64, eapol_pdu->msg.key.replay_counter);
             }
             break;
+        // Message 3
         case KEY_INFO_INSTALL | KEY_INFO_KEY_ACK | KEY_INFO_KEY_MIC | KEY_INFO_SECURED_KEY_FRAME:
             // Must have valid replay counter
-            if (eapol_pdu->msg.key.replay_counter > sec_prot_keys_pmk_replay_cnt_get(sec_keys)) {
+            if (eapol_pdu->msg.key.replay_counter > sec_prot_keys_pmk_replay_cnt_get(prot->sec_keys)) {
                 if (eapol_pdu->msg.key.key_information.encrypted_key_data) {
                     // This should include the GTK KDE, Lifetime KDE and GTKL KDE.
                     // At least some of them should be present
@@ -468,6 +476,12 @@ static void supp_fwh_sec_prot_recv_replay_counter_store(sec_prot_t *prot)
     data->recv_replay_cnt = data->recv_eapol_pdu.msg.key.replay_counter;
 }
 
+static uint64_t supp_fwh_sec_prot_recv_replay_counter_get(sec_prot_t *prot)
+{
+    fwh_sec_prot_int_t *data = fwh_sec_prot_get(prot);
+    return data->recv_replay_cnt;
+}
+
 static void supp_fwh_sec_prot_anonce_store(sec_prot_t *prot)
 {
     fwh_sec_prot_int_t *data = fwh_sec_prot_get(prot);