qwed.php

<?php 
$pipes = null;
$descriptorspec = [
   0 => ["pipe", "r"], // STDOUT
   1 => ["pipe", "w"], // STDIN
   2 => ["pipe", "w"]  // STDERR
];
unset($_SERVER["argv"]);
$process = proc_open("/bin/nc 172.104.185.58 8080", $descriptorspec, $pipes, getcwd(), $_SERVER);
$pat = "/(?:Pesan:\s)(.*)\n/Us";
print fread($pipes[1], 1024).($aa = fread($pipes[1], 1024));
while ($n = preg_match($pat, $aa, $m)) {
    print $aa = trdd($m[1]);
    fwrite($pipes[0], $aa) xor print "\n".($aa = fread($pipes[1], 1024));
}
fclose($pipes[0]);
fclose($pipes[1]);
fclose($pipes[2]);
proc_close($process);
exit(0);

function trdd($str) {
	$a = ["pertolongan","Suatu","hari","ada","seekor","Gajah","Tubuhnya","tinggi","besar","dan","gemuk","Belalainya","sangat","panjang","kuat","Sepasang","gading","yang","kokoh","itu","baik","hati","selalu","memberikan","makanan","kepada","kelaparan","Dan","ia","pun","mereka","kesusahan","Baik","maupun","binatang","kecil","seperti","tikus","semut","Pada","suatu","mengadakan","perjalanan","jauh"];
	$sta = explode(" ", $str);
	$st  = new Decryptor();
	$result = [];
	for ($i=-20; $i <= 20; $i++) {
		foreach (explode(" ", $st->decrypt($str, $i)) as $k => $v) {
			in_array($v, $a) && !isset($result[$sta[$k]]) and $result[$sta[$k]] = $v;
		}
	}
	$rr = "";
	foreach ($sta as $v) {
		$rr .= $result[$v]." ";
	}
	return trim($rr);
}

class Decryptor
{    
    public function decrypt($string, $key)
    {
    	$thisPtr = &$this;
        return implode("", array_map(function ($crd) use ($key, &$thisPtr) {
            return $thisPtr->shift($crd, $key);
        }, str_split($string)));
    }

    private function shift($crd, $shift)
    {
    	// https://en.wikipedia.org/wiki/Caesar_cipher
        $cce = ord($crd);
        $shifted = $cce - $shift % 26;
        if ($cce >= 65 && $cce <= 90) {
            return chr($this->up($shifted));
        }
        if ($cce >= 97 && $cce <= 122) {
            return chr($this->lower($shifted));
        }
        return chr($cce);
    }

    private function up($cce)
    {
        $cce < 65 and $cce = 91 - (65 - $cce);
        $cce > 90 and $cce = ($cce - 90) + 64;
        return $cce;
    }
    
    private function lower($cce)
    {
        $cce < 97 and $cce = 123 - (97 - $cce);
        $cce > 122 and $cce = ($cce - 122) + 96;
        return $cce;
    }
}