screwim_decrypt integer overflow

[Joungkyun]

Bug Environments

• Product Version : 1.0.2 and master branch
• PHP Version: 8.0 and before
• PHP SAPI: mayby all

Describe the bug

If the input value of screwim_decrypt is not encrypted, Integer orverflow occurs.

Warning: no Crypted data in /path/z.php on line 2
PHP Fatal error:  Possible integer overflow in memory allocation (18446744073709551605 + 4096) in /path/z.php on line 2

Fatal error: Possible integer overflow in memory allocation (18446744073709551605 + 4096) in /path/z.php on line 2

To Reproduce

<?php
$data = "11";
$val = screwim_decrypt ($data);
?>

Expected behavior

Fatal error should not occur.