FOPO Decoder

<title>FOPO Decoder</title>
<center>
    <h1>FOPO Decoder</h1>
    <form method="POST">
        <br />
        <textarea name="contents" style="width: 615px; height: 141px;"></textarea>
        <br /><br />
        <input type="submit" name="dec" value="Decode">
    </form>
    <br /><br />
<?php
/*
FOPO PHP Deobfuscator script
Description: Deobfuscator script for FOPO PHP obfuscated files
Author: Antelox
Version: 0.22
Date: 05/04/2017
Coded by Antelox
Twitter: @Antelox
UIC R.E. Academy - quequero.org
Copyright (C) 2017 - MIT License
*PHP script version*
Online version: https://glot.io/snippets/efruafhnez
This is the updated version after that FOPO PHP Obfuscator's author has updated
his obfuscation algorithm
If it doesn't work in the future, please send me an email at
anteloxrce(at)gmail(dot)com
and I'll will try to update the script quickly. Otherwise, fork it
and make appropriate changes. =)
*/
set_time_limit(0);

if (isset($_POST['dec'])) {
    $contents = (isset($_POST['contents']) && !empty($_POST['contents'])) ? $_POST['contents'] : null;
    if (!is_null($contents)) {
        if (preg_match('/Obfuscation provided by FOPO - Free Online PHP Obfuscator:/', $contents) === 0)
            die("*ERROR: Provided a PHP script not obfuscated with FOPO PHP Obfuscator!");
        else{
        $contents = preg_replace('/\/\/?\s*\*[\s\S]*?\*\s*\/\/?/', '', $contents);
        $eval = explode('(', $contents);
        $base64 = explode('"', $eval[2]);
        $i1 = explode("eval", base64_decode($base64[1]));
        $i2 = explode(":", $i1[1]);
        $i3 = explode("\"", $i2[1]);
        $encodedlayer = gzinflate(base64_decode(str_rot13($i3[1])));
        while (!preg_match('/\?\>/', $encodedlayer)) {
            $dl = explode("\"", $encodedlayer);
            if (sizeof($dl) > 7) {
                $nextlayer = gzinflate(base64_decode(str_rot13($dl[7])));
                $encodedlayer = $nextlayer;
            }else{
                $nextlayer = gzinflate(base64_decode($dl[5]));
                $encodedlayer = $nextlayer;
            }
        }

        $decoded = substr($encodedlayer, strpos($encodedlayer, '?>') + 2, strlen($encodedlayer));
        echo "<textarea style=\"width: 615px; height: 141px;\" readonly>" . htmlentities($decoded) . "</textarea>";
    }
}
}