public function checkSignature($signature = null, $timestamp = null, $nonce = null)
{
$request = Yii::$app->request;
$signature === null && ($signature = $request->get('signature', ''));
$timestamp === null && ($timestamp = $request->get('timestamp', ''));
$nonce === null && ($nonce = $request->get('nonce', ''));
$tmpArr = [$this->token, $timestamp, $nonce];
sort($tmpArr, SORT_STRING);
$tmpStr = implode($tmpArr);
return sha1($tmpStr) == $signature;
}