web16.php

<?php

show_source(__FILE__);

$v1=0;$v2=0;$v3=0;

$a=(array)json_decode(@$_GET['foo']);

if(is_array($a)){

    var_dump($a);

    is_numeric(@$a["bar1"])?die("nope"):NULL;
    if(@$a["bar1"]){
        ($a["bar1"]>2016)?$v1=1:NULL;
    }
    if(is_array(@$a["bar2"])){
        if(count($a["bar2"])!==5 OR !is_array($a["bar2"][0])) die("nope");
        $pos = array_search("nudt", $a["a2"]);
        $pos===false?die("nope"):NULL;
        foreach($a["bar2"] as $key=>$val){
            $val==="nudt"?die("nope"):NULL;
        }
        $v2=1;
    }
}


$c=@$_GET['cat'];
$d=@$_GET['dog'];
if(@$c[1]){
    if(!strcmp($c[1],$d) && $c[1]!==$d){
        echo $c[0];
        eregi("3|1|c",$d.$c[0])?die("nope"):NULL; 
        strpos(($c[0].$d), "htctf2016")?$v3=1:NULL;
    }
}
if($v1 && $v2 && $v3){
    include "flag.php";
    echo $flag;
}
?>