From 55d991d261234d3828eca5fdb5c8c40e58857ee7 Mon Sep 17 00:00:00 2001
From: flashwave <me@flash.moe>
Date: Thu, 3 Jan 2019 18:00:56 +0100
Subject: [PATCH] Add ETag cache support to avatars, backgrounds and proxied
 media.

---
 public/profile.php | 32 +++++++++++++++++++++++++-------
 public/proxy.php   |  8 ++++++++
 utility.php        |  2 +-
 3 files changed, 34 insertions(+), 8 deletions(-)

diff --git a/public/profile.php b/public/profile.php
index 13cf00ed..cb234ae5 100644
--- a/public/profile.php
+++ b/public/profile.php
@@ -27,13 +27,13 @@ switch ($mode) {
             if (is_file($croppedAvatar)) {
                 $avatarFilename = $croppedAvatar;
             } else {
-                $original_avatar = build_path(MSZ_STORAGE, 'avatars/original', $userAvatar);
+                $originalAvatar = build_path(MSZ_STORAGE, 'avatars/original', $userAvatar);
 
-                if (is_file($original_avatar)) {
+                if (is_file($originalAvatar)) {
                     try {
                         file_put_contents(
                             $croppedAvatar,
-                            crop_image_centred_path($original_avatar, 200, 200)->getImagesBlob(),
+                            crop_image_centred_path($originalAvatar, 200, 200)->getImagesBlob(),
                             LOCK_EX
                         );
 
@@ -44,7 +44,16 @@ switch ($mode) {
             }
         }
 
+        $fileTime = filemtime($avatarFilename);
+        $entityTag = "\"avatar-{$userId}-{$fileTime}\"";
+
+        if (!empty($_SERVER['HTTP_IF_NONE_MATCH']) && strtolower($_SERVER['HTTP_IF_NONE_MATCH']) === $entityTag) {
+            http_response_code(304);
+            break;
+        }
+
         header('Content-Type: ' . mime_content_type($avatarFilename));
+        header("ETag: {$entityTag}");
         echo file_get_contents($avatarFilename);
         break;
 
@@ -56,18 +65,27 @@ switch ($mode) {
             break;
         }
 
-        $user_background = build_path(
+        $userBackground = build_path(
             create_directory(build_path(MSZ_STORAGE, 'backgrounds/original')),
             "{$userId}.msz"
         );
 
-        if (!is_file($user_background)) {
+        if (!is_file($userBackground)) {
             echo render_error(404);
             break;
         }
 
-        header('Content-Type: ' . mime_content_type($user_background));
-        echo file_get_contents($user_background);
+        $fileTime = filemtime($userBackground);
+        $entityTag = "\"background-{$userId}-{$fileTime}\"";
+
+        if (!empty($_SERVER['HTTP_IF_NONE_MATCH']) && strtolower($_SERVER['HTTP_IF_NONE_MATCH']) === $entityTag) {
+            http_response_code(304);
+            break;
+        }
+
+        header('Content-Type: ' . mime_content_type($userBackground));
+        header("ETag: {$entityTag}");
+        echo file_get_contents($userBackground);
         break;
 
     default:
diff --git a/public/proxy.php b/public/proxy.php
index 5720c256..94b087ad 100644
--- a/public/proxy.php
+++ b/public/proxy.php
@@ -56,6 +56,13 @@ curl_setopt_array($curl, [
 $curlBody = curl_exec($curl);
 curl_close($curl);
 
+$entityTag = '"' . hash('sha256', $curlBody) . '"';
+
+if (!empty($_SERVER['HTTP_IF_NONE_MATCH']) && strtolower($_SERVER['HTTP_IF_NONE_MATCH']) === $entityTag) {
+    http_response_code(304);
+    return;
+}
+
 $finfo = finfo_open(FILEINFO_MIME_TYPE);
 $fileMime = finfo_buffer($finfo, $curlBody);
 finfo_close($finfo);
@@ -71,5 +78,6 @@ $fileName = basename($parsedUrl['path'] ?? "proxied-image-{$expectedHash}");
 header("Content-Type: {$fileMime}");
 header("Content-Length: {$fileSize}");
 header("Content-Disposition: inline; filename=\"{$fileName}\"");
+header("ETag: {$entityTag}");
 
 echo $curlBody;
diff --git a/utility.php b/utility.php
index ee0cbd0d..57fc7e96 100644
--- a/utility.php
+++ b/utility.php
@@ -354,7 +354,7 @@ function proxy_media_url(?string $url): ?string
     }
 
     $secret = config_get_default('insecure', 'Proxy', 'secret_key');
-    $hash = hash_hmac('sha256', $url, $secret);
+    $hash = hash_hmac('sha256', rawurldecode($url), $secret);
     $encodedUrl = rawurlencode($url);
 
     return "/proxy.php?h={$hash}&u={$encodedUrl}";