``` <?php $signature = $_GET["signature"]; $timestamp = $_GET["timestamp"]; $nonce = $_GET["nonce"]; $param = $_GET; file_put_contents('test.txt', date('Y-m-d H:i:s').'：'.json_encode($param, JSON_UNESCAPED_UNICODE)."\r\n\r\n", FILE_APPEND); $token = 'iykjiRa6IGkyzo5TRefx295n51Ksq8is'; $tmpArr = array($token, $timestamp, $nonce); sort($tmpArr, SORT_STRING); $tmpStr = implode( $tmpArr ); $tmpStr = sha1( $tmpStr ); if ($tmpStr == $signature ) { echo $_GET['echostr']; } else { echo 'false'; } ?> ```