ctf2.php

<?php
function len($x)
{
    if (is_array($x)) return count($x);
    return strlen($x);
}


$_ = range("z-a", "A-Z");
$_ = $_[51] . $_[53] . $_[38];
$zyx = range("z-a", "A-Z");
$xyz = $zyx[6] . $zyx[8] . $zyx[5] . $zyx[21];

$false = ${'_' . $_}["$xyz"];
$true = len($false) == 3;

for ($i = 0; $i < len($false); $i++) {
    if (strcmp($false[$i], $s3cr3t[$i]) != 0) {
        $true = false;
        echo "$wrong";
        break;
    }
}
if ($true) {
    echo $flag1;
    exit(0);
}
show_source(__DIR__ . $_SERVER['PHP_SELF']);
echo '<pre>';
var_dump(get_defined_vars());
debug_print_backtrace();