public File getRadiusKeyFile() throws GuacamoleException {
        return environment.getProperty(
            RadiusGuacamoleProperties.RADIUS_KEY_FILE,
            new File(environment.getGuacamoleHome(), "radius.key")
        );
    }
Returns the key file for the client for creating encrypted
connections to RADIUS servers as specified in
guacamole.properties.  By default a file called radius.pem
is used.

@return
    The file name for the client certificate/key pair
    for making encrypted RADIUS connections.

@throws GuacamoleException
    If guacamole.properties cannot be parsed.
extensions/guacamole-auth-radius/src/main/java/org/apache/guacamole/auth/radius/conf/ConfigurationService.java