How to hide files link from direct access in PHP (Laravel)

Now the lot of frameworks are support routing inside, the task is to prevent the user from accessing the file directly, but to convert the path using the function and output the result in browser. The sample writes on Laravel:

In start we should remove confusing url symbols. I use Helpers class to store functions.


public static function base64url_encode($s) {
return str_replace(array('+', '/'), array('-', ''), base64_encode($s));
}
public static function base64url_decode($s) {
return base64_decode(str_replace(array('-', ''), array('+', '/'), $s));
}


Then we should add the needed encode/decode functions


public static function decryptF($string)
{
$encryption_key = env('ENCRYPT_FILES_KEY'); // it's key from settings, use some string here...
assert(isset($string) === TRUE);
assert(isset($encryption_key) === TRUE);
$result = '';
$string = Helpers::base64url_decode($string);

    for ($i = 0; $i < strlen($string); $i++)
    {
        $char    = substr($string, $i, 1);
        $keychar = substr($encryption_key, ($i % strlen($encryption_key)) - 1, 1);
        $char    = chr(ord($char) - ord($keychar));
        $result .= $char;
    }

    return $result;
}

public static function encryptF($string)
{
    $encryption_key = env('ENCRYPT_FILES_KEY');

    assert(isset($string) === TRUE);
    assert(isset($encryption_key) === TRUE);

    $string = (string) $string;
    $result = '';

    for ($i = 0; $i < strlen($string); $i++)
    {
        $char    = substr($string, $i, 1);
        $keychar = substr($encryption_key, ($i % strlen($encryption_key)) - 1, 1);
        $char    = chr(ord($char) + ord($keychar));
        $result .= $char;
    }

    return Helpers::base64url_encode($result);
}