EAP server: Clear keying material on deinit

Reduce the amount of time keying material (MSK, EMSK, temporary private
data) remains in memory in EAP methods. This provides additional
protection should there be any issues that could expose process memory
to external observers.

Signed-off-by: Jouni Malinen <j@w1.fi>

src/eap_server/eap_server_mschapv2.c

@@ -91,7 +91,7 @@ static void eap_mschapv2_reset(struct eap_sm *sm, void *priv)
 		return;
 
 	os_free(data->peer_challenge);
-	os_free(data);
+	bin_clear_free(data, sizeof(*data));
 }