cache.efn.no/index.php at main · EFN/cache.efn.no · GitHub

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<?php
error_reporting(E_ALL);
ini_set("display_errors", 1);
define('DEBUG', 0);

$request = substr($_SERVER['REQUEST_URI'], 1);
$myhost=$_SERVER['HTTP_HOST'];

if (!$request) {
  print "<!DOCTYPE html><html lang=\"en\"><head><title>Privacy Cache</title></head><body><h1>Privacy Cache</h1><p>The Privacy Cache is a proxy that can be prepended to almost all GET requests. The Privacy Cache tries to filter out requests to websites belonging to known trackers and proxy them so to disable any tracking.</p><p><b>Disclaimer:</b> Both the DNTCache and the PrivacyCache are very much alpha software, which means it's not suitable for deployment.</p></body></html>\n";
  exit(0);
}

$valid_url=filter_var($request, FILTER_VALIDATE_URL, FILTER_FLAG_SCHEME_REQUIRED| FILTER_FLAG_HOST_REQUIRED);
if (!$valid_url) {
  header('Vary: Referer');
  header('Cache-Control: max-age=86400');
  if (array_key_exists('HTTP_REFERER', $_SERVER)) {
    $referrer=$_SERVER['HTTP_REFERER'];
    if (preg_match("/https?:\/\/${myhost}\/(https?):\/\/([^\/]+)/", $referrer, $matches)) {
      $scheme=$matches[1];
      $host=$matches[2];
      $request="$scheme://$host/$request";
      $valid_url=filter_var($request, FILTER_VALIDATE_URL, FILTER_FLAG_SCHEME_REQUIRED| FILTER_FLAG_HOST_REQUIRED);
      if ($valid_url) {
	  http_response_code(307);
	  header("Location: https://${myhost}/${valid_url}");
	  exit(0);
      }
    }
  }
  http_response_code(404);
  print "<html><body><h1>'${request}' does not meet formal requirements to be a valid URL.</body></html>\n";
  exit(0);
}
$urlc=parse_url($valid_url);
$scheme=$urlc['scheme'];
$host=$urlc['host'];

function ip_in_range( $ip, $range ) {
	if ( strpos( $range, '/' ) == false ) {
		$range .= '/32';
	}
	// $range is in IP/CIDR format eg 127.0.0.1/24
	list( $range, $netmask ) = explode( '/', $range, 2 );
	$range_decimal = ip2long( $range );
	$ip_decimal = ip2long( $ip );
	$wildcard_decimal = pow( 2, ( 32 - $netmask ) ) - 1;
	$netmask_decimal = ~ $wildcard_decimal;
	return ( ( $ip_decimal & $netmask_decimal ) == ( $range_decimal & $netmask_decimal ) );
}

function deniedHost($host) {
  if ($host == 'localhost')
    return true;
  if (filter_var($host, FILTER_VALIDATE_IP)) {
    if (ip_in_range($host, '127.0.0.1/24'))
      return true;
    if (ip_in_range($host, '10.0.0.1/8'))
      return true;
    if (ip_in_range($host, '172.16.0.1/12'))
      return true;
    if (ip_in_range($host, '192.168.0.1/16'))
      return true;
  }
return false;
}

if (deniedHost($host)) {
  http_response_code(403);
  print "<!DOCTYPE html><html lang=\"en\"><head><title>Privacy Cache</title></head><body><h1>Access denied</h1><p>You don't wanna go there</p>";
  exit(0);

}

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL,            $request);
curl_setopt($ch, CURLOPT_HEADER,         true);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_USERAGENT,'Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.13) Gecko/20080311 Firefox/2.0.0.13');
$r = curl_exec($ch);
curl_close($ch);
$r = explode("\n", $r);
if (DEBUG) {
  http_response_code(501);
  header('Content-type: text/plain');
}
header('access-control-allow-origin: *');
$n=count($r);
$headers=array();
$headers['']=$r[0];
//print($r[0]);
$status=explode(" ", $r[0])[1];
for ($i=1;$i < $n && strlen($r[$i])>1;$i++) {
  $tmp = explode(":", $r[$i]);
  $key=strtolower($tmp[0]);
  $value=implode(":", array_slice ($tmp, 1));
  $headers[$key]=$value;
  if ($key == "content-type") {
    $content_type=explode(";",$value);
    for ($j=0;$j < count($content_type);$j++) {
      $content_type[$j]=$request=ltrim($content_type[$j], ' ');
    }
  }
}
if (DEBUG)
  print_r($content_type);

if (DEBUG)
  print_r($headers);

$pt_headers=array('content-type', 'expires','date','cache-control','vary', 'location');
if (DEBUG)
  print $status."\n";
else
  http_response_code($status);
foreach ($pt_headers as $pt) {
  if (array_key_exists($pt, $headers)) {
    if (DEBUG)
      print ("$pt: $headers[$pt]");
    else {
      if ($pt == 'location') {
	$loc=ltrim($headers['location'], ' ');
	header ("location: https://${myhost}/$loc");
      }
      else
	header ("$pt: $headers[$pt]");
    }
  }
}


$body=implode("\n", array_slice ($r , $i+1));

$editTypes = array("text/css", "text/html", 'application/javascript','text/javascript');
$lut=array('' => $scheme.':', 'http:' => 'http:', 'https:' => 'https:');
$patterns=array(
		'/(http:|https:|)(\/\/.*?\.googleapis\.com)/e',
		'/(http:|https:|)(\/\/.*?\.gstatic\.com)/e',
		'/(http:|https:|)(\/\/.*?\.squarespace\.com)/e',
		);
if (in_array ( $content_type[0] , $editTypes)) {
  //$body=preg_replace($patterns, "//${myhost}/$1", $body);
  $body=preg_replace($patterns, '"//${myhost}/{$lut[\'$1\']}$2"', $body, -1, $count_replacements);
  //$body=str_replace("//fonts.googleapis.com", "//${myhost}/https://fonts.googleapis.com", $body);
}

if (! isset($count_replacements))
  $count_replacements=0;
header("X-Replacements: $count_replacements");

print($body);


//print "<html><body><h1>Support for caching is not yet implemented</h1></body></html>\n";
//http_response_code(307);
//header("Location: ${valid_url}");
?>