OSM PHP Cache

index.php

<?php
if (strpos($_SERVER['HTTP_REFERER'], 'yourdomain.com') === false) {
	header('HTTP/1.0 403 Forbidden');
	die('forbidden for '.$_SERVER['HTTP_REFERER']);
}

header('Access-Control-Allow-Origin: *');
$sSub = $_GET['sub'];
$iZ = $_GET['z'];
$iY =$_GET['y'];
$iX = $_GET['x'];
$sFormat = $_GET['format'];
$sShort = $iZ.$iX.$iY.$sSub.'.'.$sFormat;

if (!file_exists('cache/'.$sShort)) {
	$sOSMFile = file_get_contents('https://'.$sSub.'.tile.openstreetmap.org/'.$iZ.'/'.$iX.'/'.$iY.'.'.$sFormat);
	if ($sOSMFile == false) {
		header('HTTP/1.0 404 Not found');
		die('');
	}
	file_put_contents('cache/'.$sShort, $sOSMFile); 
} 
echo file_get_contents('cache/'.$sShort);
?>