Encryption::encrypt

static function encrypt(string $str, ?string $salt = null): string
{
	$key = $salt ?? COption::GetOptionString('main', 'pwdhashadd', 'ldap');
	$key1 = self::binMd5($key);
	$res = '';
	while ($str)
	{
		$m = mb_substr($str, 0, 16, 'ASCII');
		$str = mb_substr($str, 16, mb_strlen($str, 'ASCII') - 16, 'ASCII');
		$res .= self::byteXor($m, $key1, 16);
		$key1 = self::binMd5($key . $key1 . $m);
	}
	return base64_encode($res);
}