From e934d809061623f97eace064b7741b764fa03524 Mon Sep 17 00:00:00 2001
From: Matthias Schmidt <gravatronics@live.com>
Date: Thu, 6 Aug 2015 18:18:53 +0200
Subject: [PATCH] Add image proxy

---
 CHANGELOG.md                                  |  1 +
 com.woltlab.wcf/option.xml                    | 24 +++++
 wcfsetup/install/files/acp/install.php        | 12 +++
 wcfsetup/install/files/js/WCF.ImageViewer.js  |  2 +-
 .../install/files/js/WoltLab/WCF/Ui/Dialog.js |  7 +-
 .../lib/action/ImageProxyAction.class.php     | 89 +++++++++++++++++++
 .../lib/system/bbcode/ImageBBCode.class.php   | 37 +++++++-
 .../cronjob/DailyCleanUpCronjob.class.php     |  9 ++
 8 files changed, 173 insertions(+), 8 deletions(-)
 create mode 100644 wcfsetup/install/files/lib/action/ImageProxyAction.class.php

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 95c9806abf..f5c767e1ab 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -27,6 +27,7 @@
 * Replaced old user bulk processing with new implementation using the abstract bulk processing system.
 * `conditionContainers` template event in template `noticeAdd.tpl` added.
 * Use condition system for user search.
+* Image proxy for images included with the image BBCode.
 * Overhauled Redactor integration
 	* Linebreaks mode instead of using paragraphs, works better with the PHP-side parser which works with linebreaks
 	* Ported the PHP-BBCode parser, massively improves accuracy and ensures validity
\ No newline at end of file
diff --git a/com.woltlab.wcf/option.xml b/com.woltlab.wcf/option.xml
index a08960ffad..2d908677a4 100644
--- a/com.woltlab.wcf/option.xml
+++ b/com.woltlab.wcf/option.xml
@@ -204,6 +204,9 @@
 					<category name="message.general.edit">
 						<parent>message.general</parent>
 					</category>
+					<category name="message.general.image">
+						<parent>message.general</parent>
+					</category>
 				
 				<category name="message.attachment">
 					<parent>message</parent>
@@ -971,6 +974,27 @@ redis:cache_source_redis_host,!cache_source_memcached_host]]></enableoptions>
 			</option>
 			<!-- /message.general.share -->
 			
+			<!-- message.general.image -->
+			<option name="module_image_proxy">
+				<categoryname>message.general.image</categoryname>
+				<optiontype>boolean</optiontype>
+				<defaultvalue>0</defaultvalue>
+				<enableoptions><![CDATA[image_proxy_secret]]></enableoptions>
+			</option>
+			<option name="image_proxy_secret">
+				<categoryname>message.general.image</categoryname>
+				<optiontype>text</optiontype>
+				<allowemptyvalue>0</allowemptyvalue>
+			</option>
+			<option name="image_proxy_expiration">
+				<categoryname>message.general.image</categoryname>
+				<optiontype>integer</optiontype>
+				<defaultvalue>14</defaultvalue>
+				<maxvalue>30</maxvalue>
+				<minvalue>7</minvalue>
+			</option>
+			<!-- /message.general.image -->
+			
 			<!-- message.censorship -->
 			<option name="enable_censorship">
 				<categoryname>message.censorship</categoryname>
diff --git a/wcfsetup/install/files/acp/install.php b/wcfsetup/install/files/acp/install.php
index 0f6fe42d62..6f3b17dd4b 100644
--- a/wcfsetup/install/files/acp/install.php
+++ b/wcfsetup/install/files/acp/install.php
@@ -2,6 +2,7 @@
 use wcf\system\session\SessionHandler;
 use wcf\system\WCF;
 use wcf\util\DateUtil;
+use wcf\util\StringUtil;
 
 /**
  * @author	Marcel Werk
@@ -64,3 +65,14 @@ if ($timezone = @date_default_timezone_get()) {
 		$statement->execute(array($timezone, 'timezone'));
 	}
 }
+
+// set image proxy secret
+$sql = "UPDATE	wcf".WCF_N."_option
+	SET	optionValue = ?
+	WHERE	optionName = ?";
+$statement = WCF::getDB()->prepareStatement($sql);
+$statement->execute([
+	StringUtil::getRandomID(),
+	'image_proxy_secret'
+]);
+
diff --git a/wcfsetup/install/files/js/WCF.ImageViewer.js b/wcfsetup/install/files/js/WCF.ImageViewer.js
index d251716aba..0ee764c9ac 100644
--- a/wcfsetup/install/files/js/WCF.ImageViewer.js
+++ b/wcfsetup/install/files/js/WCF.ImageViewer.js
@@ -1217,7 +1217,7 @@ $.widget('ui.wcfImageViewer', {
 			
 			$images.push({
 				image: {
-					fullURL: $link.prop('href'),
+					fullURL: $thumbnail.data('source') ? $thumbnail.data('source').replace(/\\\//g, '/') : $link.prop('href'),
 					link: '',
 					title: $link.prop('title'),
 					url: $link.prop('href'),
diff --git a/wcfsetup/install/files/js/WoltLab/WCF/Ui/Dialog.js b/wcfsetup/install/files/js/WoltLab/WCF/Ui/Dialog.js
index db2821e5db..b2e3a42b14 100644
--- a/wcfsetup/install/files/js/WoltLab/WCF/Ui/Dialog.js
+++ b/wcfsetup/install/files/js/WoltLab/WCF/Ui/Dialog.js
@@ -295,12 +295,7 @@ define(
 					content.innerHTML = html;
 				}
 				else if (html instanceof DocumentFragment) {
-					if (html.children[0].nodeName !== 'div' || html.childElementCount > 1) {
-						content.appendChild(html);
-					}
-					else {
-						content = html.children[0];
-					}
+					content.appendChild(html);
 				}
 				
 				content.id = id;
diff --git a/wcfsetup/install/files/lib/action/ImageProxyAction.class.php b/wcfsetup/install/files/lib/action/ImageProxyAction.class.php
new file mode 100644
index 0000000000..ce138aa9d2
--- /dev/null
+++ b/wcfsetup/install/files/lib/action/ImageProxyAction.class.php
@@ -0,0 +1,89 @@
+<?php
+namespace wcf\action;
+use wcf\system\exception\IllegalLinkException;
+use wcf\system\exception\SystemException;
+use wcf\util\FileUtil;
+use wcf\util\HTTPRequest;
+use wcf\util\StringUtil;
+
+/**
+ * Proxies requests for embedded images.
+ * 
+ * @author	Matthias Schmidt
+ * @copyright	2001-2015 WoltLab GmbH
+ * @license	GNU Lesser General Public License <http://opensource.org/licenses/lgpl-license.php>
+ * @package	com.woltlab.wcf
+ * @subpackage	action
+ * @category	Community Framework
+ */
+class ImageProxyAction extends AbstractAction {
+	/**
+	 * hashed image proxy secret and image url
+	 * @var	string
+	 */
+	public $hash = '';
+	
+	/**
+	 * image url
+	 * @var	string
+	 */
+	public $url = '';
+	
+	/**
+	 * @see	\wcf\action\IAction::readParameters()
+	 */
+	public function readParameters() {
+		parent::readParameters();
+		
+		if (isset($_REQUEST['url'])) $this->url = urldecode(StringUtil::trim($_REQUEST['url']));
+		if (isset($_REQUEST['hash'])) $this->hash = StringUtil::trim($_REQUEST['hash']);
+	}
+	
+	/**
+	 * @see	\wcf\action\IAction::execute()
+	 */
+	public function execute() {
+		parent::execute();
+		
+		$hash = sha1(IMAGE_PROXY_SECRET.$this->url);
+		if ($this->hash != $hash) {
+			throw new IllegalLinkException();
+		}
+		
+		try {
+			$request = new HTTPRequest($this->url);
+			$request->execute();
+			$reply = $request->getReply();
+			
+			$fileExtension = '';
+			if (($position = mb_strrpos($this->url, '.')) !== false) {
+				$fileExtension = mb_strtolower(mb_substr($this->url, $position + 1));
+			}
+			
+			// check if requested content is image
+			if (!isset($reply['headers']['Content-Type']) || !StringUtil::startsWith($reply['headers']['Content-Type'], 'image/')) {
+				throw new IllegalLinkException();
+			}
+			
+			// save image
+			$fileLocation = WCF_DIR.'images/proxy/'.substr($hash, 0, 2).'/'.$hash.($fileExtension ? '.'.$fileExtension : '');
+			$dir = dirname($fileLocation);
+			if (!@file_exists($dir)) {
+				FileUtil::makePath($dir, 0777);
+			}
+			file_put_contents($fileLocation, $reply['body']);
+			
+			// update mtime for correct expiration calculation
+			@touch($fileLocation);
+			
+			$this->executed();
+			
+			@header('Content-Type: '.$reply['headers']['Content-Type']);
+			@readfile($fileLocation);
+			exit;
+		}
+		catch (SystemException $e) {
+			throw new IllegalLinkException();
+		}
+	}
+}
diff --git a/wcfsetup/install/files/lib/system/bbcode/ImageBBCode.class.php b/wcfsetup/install/files/lib/system/bbcode/ImageBBCode.class.php
index 0b6c05123f..44172ebad8 100644
--- a/wcfsetup/install/files/lib/system/bbcode/ImageBBCode.class.php
+++ b/wcfsetup/install/files/lib/system/bbcode/ImageBBCode.class.php
@@ -1,6 +1,8 @@
 <?php
 namespace wcf\system\bbcode;
 use wcf\util\StringUtil;
+use wcf\system\WCF;
+use wcf\system\request\LinkHandler;
 
 /**
  * Parses the [img] bbcode tag.
@@ -23,6 +25,12 @@ class ImageBBCode extends AbstractBBCode {
 		}
 		
 		if ($parser->getOutputType() == 'text/html') {
+			$dataSource = '';
+			if (MODULE_IMAGE_PROXY) {
+				$dataSource = $src;
+				$src = $this->getProxyLink($src);
+			}
+			
 			$float = '';
 			if (isset($openingTag['attributes'][1])) {
 				$float = $openingTag['attributes'][1];
@@ -40,7 +48,7 @@ class ImageBBCode extends AbstractBBCode {
 				$style .= 'width: ' . $width . 'px;';
 			}
 			
-			return '<img src="'.$src.'" class="jsResizeImage" alt=""'.($style ? ' style="' . $style . '"' : '').' />';
+			return '<img src="'.$src.'" class="jsResizeImage" alt=""'.($style ? ' style="' . $style . '"' : '').($dataSource ? ' data-source="'.StringUtil::encodeJS($dataSource).'"' : '').' />';
 		}
 		else if ($parser->getOutputType() == 'text/simplified-html') {
 			$src = StringUtil::decodeHTML($src);
@@ -52,4 +60,31 @@ class ImageBBCode extends AbstractBBCode {
 			return '';
 		}
 	}
+	
+	/**
+	 * Returns the link to the cached image (or the link to fetch the image
+	 * using the image proxy).
+	 * 
+	 * @param	string		$link
+	 * @return	string
+	 */
+	protected function getProxyLink($link) {
+		$hash = sha1(IMAGE_PROXY_SECRET.$link);
+		$fileExtension = '';
+		if (($position = mb_strrpos($link, '.')) !== false) {
+			$fileExtension = mb_strtolower(mb_substr($link, $position + 1));
+		}
+		
+		$path = 'images/proxy/'.substr($hash, 0, 2).'/'.$hash.($fileExtension ? '.'.$fileExtension : '');
+		
+		$fileLocation = WCF_DIR.$path;
+		if (file_exists($fileLocation)) {
+			return WCF::getPath().$path;
+		}
+		
+		return LinkHandler::getInstance()->getLink('ImageProxy', [
+			'hash' => $hash,
+			'url' => urlencode($link)
+		]);
+	}
 }
diff --git a/wcfsetup/install/files/lib/system/cronjob/DailyCleanUpCronjob.class.php b/wcfsetup/install/files/lib/system/cronjob/DailyCleanUpCronjob.class.php
index 2778be1ac7..f4bfb8718e 100644
--- a/wcfsetup/install/files/lib/system/cronjob/DailyCleanUpCronjob.class.php
+++ b/wcfsetup/install/files/lib/system/cronjob/DailyCleanUpCronjob.class.php
@@ -181,5 +181,14 @@ class DailyCleanUpCronjob extends AbstractCronjob {
 				}
 			}
 		}));
+		
+		// clean up proxy images
+		if (MODULE_IMAGE_PROXY) {
+			DirectoryUtil::getInstance(WCF_DIR.'images/proxy/')->executeCallback(new Callback(function($filename, $object) {
+				if ($object->isFile() && $object->getMTime() < TIME_NOW - 86400 * IMAGE_PROXY_EXPIRATION) {
+					@unlink($filename);
+				}
+			}));
+		}
 	}
 }
-- 
2.20.1