<?php
/**
* @brief Image Proxy
* @author <a href='https://www.invisioncommunity.com'>Invision Power Services, Inc.</a>
* @copyright (c) Invision Power Services, Inc.
* @license https://www.invisioncommunity.com/legal/standards/
* @package Invision Community
* @since 29 Jun 2015
* @version SVN_VERSION_NUMBER
*/
/* Init */
define('REPORT_EXCEPTIONS', TRUE);
require_once str_replace( 'applications/core/interface/imageproxy/imageproxy.php', '', str_replace( '\\', '/', __FILE__ ) ) . 'init.php';
$url = \IPS\Request::i()->img;
/* Check for a valid key */
if ( !\IPS\Login::compareHashes( hash_hmac( "sha256", $url, \IPS\Settings::i()->site_secret_key ), (string) \IPS\Request::i()->key ) )
{
\IPS\Output::i()->sendOutput( NULL, 403 );
}
/* Check the cache */
try
{
$cacheEntry = \IPS\Db::i()->select( '*', 'core_image_proxy', array( 'md5_url=?', md5( $url ) ) )->first();
/* If we have a cache entry, but it is over an hour old and the location is NULL, try to refetch */
if( $cacheEntry['location'] === NULL AND $cacheEntry['cache_time'] < time() - 3600 )
{
\IPS\Db::i()->delete( 'core_image_proxy', array( 'md5_url=?', $cacheEntry['md5_url'] ) );
throw new \UnderflowException;
}
if ( $cacheEntry['location'] )
{
/* Set the cache expiration time */
$cacheExpires = new \DateTime; // Use of \DateTime is intentional, do not replace with \IPS\DateTime
$cacheExpires->setTimestamp( (int) $cacheEntry['cache_time'] );
$cacheExpires->add( new \DateInterval( ( \IPS\Settings::i()->image_proxy_cache_period ) ? sprintf( 'P%dD', \IPS\Settings::i()->image_proxy_cache_period ) : 'P1Y' ) );
$file = \IPS\File::get( 'core_Imageproxycache', $cacheEntry['location'] );
}
else
{
\IPS\Output::i()->sendOutput( NULL, 404 );
}
}
/* Not in cache - fetch and store */
catch ( \UnderflowException $e )
{
/* If the image proxy is disabled and the image isn't already stored, 301. This prevents images being stored when image proxy is disabled */
if( !\IPS\Settings::i()->remote_image_proxy )
{
\IPS\Output::i()->redirect( \IPS\Http\Url::external( mb_substr( $url, 0, 2 ) === '//' ? "http:{$url}" : $url ) );
}
/* Set the cache expiration time */
$cacheExpires = new \DateTime; // Use of \DateTime is intentional, do not replace with \IPS\DateTime
$cacheExpires->add( new \DateInterval( ( \IPS\Settings::i()->image_proxy_cache_period ) ? sprintf( 'P%dD', \IPS\Settings::i()->image_proxy_cache_period ) : 'P1Y' ) );
/* First, let's store a placeholder row that we will later update - this prevents being able to DOS the server if the image is crazy */
\IPS\Db::i()->replace( 'core_image_proxy', array(
'md5_url' => md5( $url ),
'location' => NULL,
'cache_time' => time(),
) );
try
{
$output = \IPS\Http\Url::external( mb_substr( $url, 0, 2 ) === '//' ? "http:{$url}" : $url )->request()->get();
/* Check it's a valid image */
$image = \IPS\Image::create( (string) $output );
$imageExtension = $image->type;
}
catch ( \Exception $e )
{
\IPS\Output::i()->sendOutput( NULL, 502 );
}
/* Work out an appropriate filename */
$extension = mb_substr( $url, mb_strrpos( $url, '.' ) + 1 );
if ( in_array( $extension, \IPS\Image::$imageExtensions ) )
{
$filename = mb_substr( $url, mb_strrpos( $url, '/' ) + 1 );
if ( mb_strlen( $filename ) > 200 )
{
$filename = mb_substr( $filename, 0, 150 ) . '.' . $extension;
}
}
else
{
$filename = md5( mt_rand() ) . '.' . $imageExtension;
}
/* Cache */
try
{
$thumbDims = \IPS\Settings::i()->attachment_image_size ? explode( 'x', \IPS\Settings::i()->attachment_image_size ) : array( 1000, 750 );
$image->resizeToMax( $thumbDims[0], $thumbDims[1] );
$imageData = (string) $image;
unset( $image, $output );
$file = \IPS\File::create( 'core_Imageproxycache', $filename, $imageData, 'imageproxy' );
$location = (string) $file;
}
catch( \DomainException $e )
{
\IPS\Log::log( $e, 'imageproxy' );
$location = NULL;
}
\IPS\Db::i()->replace( 'core_image_proxy', array(
'md5_url' => md5( $url ),
'location' => $location,
'cache_time' => time(),
) );
if( $location === NULL )
{
\IPS\Output::i()->sendOutput( NULL, 404 );
}
}
try
{
/* Output */
\IPS\Output::i()->sendOutput( $file->contents(), 200, \IPS\File::getMimeType( $file->filename ), array(
'cache-control' => 'public, max_age=' . max( ( $cacheExpires->getTimestamp() - time() ), 0 ) . ', must-revalidate',
'expires' => $cacheExpires->format( 'D, d M Y H:i:s \G\M\T' )
) );
}
catch ( \RuntimeException $e )
{
\IPS\Log::debug( "Failed fetching proxy image", 'imageProxy' );
}