concrete/src/Api/OAuth/Client/ClientFactory.php
protected function generateString($length)
    {
        $bytes = ceil($length / 2);
        $string = bin2hex(random_bytes($bytes));

        return substr($string, 0, $length);
    }
protected function generateString($length)
    {
        $bytes = ceil($length / 2);
        $string = bin2hex(random_bytes($bytes));

        return substr($string, 0, $length);
    }
protected function generateString ( $ length ) { $ bytes = ceil ( $ length / 2 ) ; $ string = bin2hex ( random_bytes ( $ bytes ) ) ; return substr ( $ string , 0 , $ length ) ; }
Generate a cryptographically secure strig

@param $length
@return bool|string
Generate a cryptographically secure strig