Filter out unlikely "pre-shared key may be incorrect" messages

Add a function to filter out known cases of disconnection during 4-way
handshake that are caused by something else than mismatch in PSK. This
commit adds the case where the local end determines a mismatch in
WPA/RSN element between Beacon/Probe Response frames and EAPOL-Key msg
3/4.

This can avoid some potentially confusing "WPA: 4-Way Handshake failed -
pre-shared key may be incorrect" ctrl_iface messages.

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

diff --git a/wpa_supplicant/events.c b/wpa_supplicant/events.c
index 5399f76d183ef8e137ce26ca1425e93b16914aca..53b8338b2a8b4380449b3f9847271cff63939da5 100644 (file)
--- a/wpa_supplicant/events.c
+++ b/wpa_supplicant/events.c
@@ -1815,6 +1815,28 @@ static void wpa_supplicant_event_disassoc(struct wpa_supplicant *wpa_s,
 }
 
 
+static int could_be_psk_mismatch(struct wpa_supplicant *wpa_s, u16 reason_code,
+                                int locally_generated)
+{
+       if (wpa_s->wpa_state != WPA_4WAY_HANDSHAKE ||
+           !wpa_key_mgmt_wpa_psk(wpa_s->key_mgmt))
+               return 0; /* Not in 4-way handshake with PSK */
+
+       /*
+        * It looks like connection was lost while trying to go through PSK
+        * 4-way handshake. Filter out known disconnection cases that are caused
+        * by something else than PSK mismatch to avoid confusing reports.
+        */
+
+       if (locally_generated) {
+               if (reason_code == WLAN_REASON_IE_IN_4WAY_DIFFERS)
+                       return 0;
+       }
+
+       return 1;
+}
+
+
 static void wpa_supplicant_event_disassoc_finish(struct wpa_supplicant *wpa_s,
                                                 u16 reason_code,
                                                 int locally_generated)
@@ -1840,8 +1862,7 @@ static void wpa_supplicant_event_disassoc_finish(struct wpa_supplicant *wpa_s,
                return;
        }
 
-       if (wpa_s->wpa_state == WPA_4WAY_HANDSHAKE &&
-           wpa_key_mgmt_wpa_psk(wpa_s->key_mgmt)) {
+       if (could_be_psk_mismatch(wpa_s, reason_code, locally_generated)) {
                wpa_msg(wpa_s, MSG_INFO, "WPA: 4-Way Handshake failed - "
                        "pre-shared key may be incorrect");
                wpas_auth_failed(wpa_s);