Add settings validation to prevent abuse

src/main.py

@@ -2,10 +2,11 @@ import logging
 from volvo import authorize
 from mqtt import update_loop, connect
 from const import VERSION
-from util import set_tz, setup_logging, set_mqtt_settings
+from util import set_tz, setup_logging, set_mqtt_settings, validate_settings
 
 
 if __name__ == '__main__':
+    validate_settings()
     set_tz()
     set_mqtt_settings()
     setup_logging()

src/util.py

@@ -136,3 +136,14 @@ def set_mqtt_settings():
         config.settings["mqtt"]["port"] = broker_port
         config.settings["mqtt"]["username"] = broker_user
         config.settings["mqtt"]["password"] = broker_pass
+
+
+def validate_settings():
+    setting_keys = settings.volvoData["vccapikey"]
+    if isinstance(setting_keys, list):
+        if len(setting_keys) > 3:
+            raise Exception("Settings invalid! Maximum allowed vccapikeys are three!")
+
+    update_interval = settings["updateInterval"]
+    if update_interval < 60:
+        raise Exception("Settings invalid! Minimum allowed update interval is 60 seconds!")