From: joshuaruesweg <ruesweg@woltlab.com>
Date: Fri, 12 Mar 2021 10:38:03 +0000 (+0100)
Subject: Use random imageHash to avoid collisions
X-Git-Tag: 5.4.0_Alpha_1~146^2~6
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=e0a8b142e57430cd2541868fe35ac44c7588cda3;p=GitHub%2FWoltLab%2FWCF.git

Use random imageHash to avoid collisions
---

diff --git a/wcfsetup/install/files/lib/system/background/job/UnfurlUrlBackgroundJob.class.php b/wcfsetup/install/files/lib/system/background/job/UnfurlUrlBackgroundJob.class.php
index 5345d247ba..b1a114f665 100644
--- a/wcfsetup/install/files/lib/system/background/job/UnfurlUrlBackgroundJob.class.php
+++ b/wcfsetup/install/files/lib/system/background/job/UnfurlUrlBackgroundJob.class.php
@@ -201,14 +201,17 @@ final class UnfurlUrlBackgroundJob extends AbstractBackgroundJob
 
     private function saveImage(array $imageData, string $image): string
     {
-        $imageHash = \sha1($image);
+        do {
+            $imageHash = StringUtil::getRandomID();
+
+            $path = WCF_DIR . UnfurlUrl::IMAGE_DIR . \substr($imageHash, 0, 2) . '/';
+        } while (!empty(glob($path . $imageHash . '.*')));
 
-        $path = WCF_DIR . UnfurlUrl::IMAGE_DIR . \substr($imageHash, 0, 2);
         FileUtil::makePath($path);
 
         $extension = $this->getImageExtension($imageData);
 
-        $fileLocation = $path . '/' . $imageHash . '.' . $extension;
+        $fileLocation = $path . $imageHash . '.' . $extension;
 
         \file_put_contents($fileLocation, $image);