From 52d7ce1a859f7073a9122473a7631836dc4fca94 Mon Sep 17 00:00:00 2001
From: Alexander Ebert <ebert@woltlab.com>
Date: Tue, 16 Aug 2016 20:06:31 +0200
Subject: [PATCH] Added support for image proxy

---
 .../output/node/HtmlOutputNodeImg.class.php   | 72 +++++++++++++++++++
 1 file changed, 72 insertions(+)
 create mode 100644 wcfsetup/install/files/lib/system/html/output/node/HtmlOutputNodeImg.class.php

diff --git a/wcfsetup/install/files/lib/system/html/output/node/HtmlOutputNodeImg.class.php b/wcfsetup/install/files/lib/system/html/output/node/HtmlOutputNodeImg.class.php
new file mode 100644
index 0000000000..253be2eb9f
--- /dev/null
+++ b/wcfsetup/install/files/lib/system/html/output/node/HtmlOutputNodeImg.class.php
@@ -0,0 +1,72 @@
+<?php
+namespace wcf\system\html\output\node;
+use wcf\system\html\node\AbstractHtmlNodeProcessor;
+use wcf\system\request\LinkHandler;
+use wcf\system\WCF;
+use wcf\util\CryptoUtil;
+use wcf\util\exception\CryptoException;
+
+/**
+ * Processes images.
+ * 
+ * @author      Alexander Ebert
+ * @copyright   2001-2016 WoltLab GmbH
+ * @license     GNU Lesser General Public License <http://opensource.org/licenses/lgpl-license.php>
+ * @package     WoltLabSuite\Core\System\Html\Output\Node
+ * @since       3.0
+ */
+class HtmlOutputNodeImg extends AbstractHtmlOutputNode {
+	/**
+	 * @inheritDoc
+	 */
+	protected $tagName = 'img';
+	
+	/**
+	 * @inheritDoc
+	 */
+	public function process(array $elements, AbstractHtmlNodeProcessor $htmlNodeProcessor) {
+		if (!MODULE_IMAGE_PROXY) {
+			return;
+		}
+		
+		/** @var \DOMElement $element */
+		foreach ($elements as $element) {
+			$src = $element->getAttribute('src');
+			if ($src) {
+				$element->setAttribute('src', $this->getProxyLink($src));
+			}
+		}
+	}
+	
+	/**
+	 * Returns the link to the cached image (or the link to fetch the image
+	 * using the image proxy).
+	 *
+	 * @param	string		$link
+	 * @return	string
+	 * @since	3.0
+	 */
+	protected function getProxyLink($link) {
+		try {
+			$key = CryptoUtil::createSignedString($link);
+			// does not need to be secure, just sufficiently "random"
+			$fileName = sha1($key);
+			
+			$fileExtension = pathinfo($link, PATHINFO_EXTENSION);
+			
+			$path = 'images/proxy/'.substr($fileName, 0, 2).'/'.$fileName.($fileExtension ? '.'.$fileExtension : '');
+			
+			$fileLocation = WCF_DIR.$path;
+			if (file_exists($fileLocation)) {
+				return WCF::getPath().$path;
+			}
+			
+			return LinkHandler::getInstance()->getLink('ImageProxy', [
+				'key' => $key
+			]);
+		}
+		catch (CryptoException $e) {
+			return $link;
+		}
+	}
+}
-- 
2.20.1