Throw error if incoming attachment has mismatched attachment size

signalapp · Feb 21, 2019 · 7c4ba54 · 7c4ba54
1 parent f5af063
commit 7c4ba54
Showing 1 changed file with 9 additions and 1 deletion.
diff --git a/libtextsecure/message_receiver.js b/libtextsecure/message_receiver.js
@@ -1216,14 +1216,22 @@ MessageReceiver.prototype.extend({
   },
   async downloadAttachment(attachment) {
     const encrypted = await this.server.getAttachment(attachment.id);
-    const { key, digest } = attachment;
+    const { key, digest, size } = attachment;
 
     const data = await textsecure.crypto.decryptAttachment(
       encrypted,
       window.Signal.Crypto.base64ToArrayBuffer(key),
       window.Signal.Crypto.base64ToArrayBuffer(digest)
     );
 
+    if (!size || size !== data.byteLength) {
+      throw new Error(
+        `downloadAttachment: Size ${size} did not match downloaded attachment size ${
+          data.byteLength
+        }`
+      );
+    }
+
     return {
       ..._.omit(attachment, 'digest', 'key'),
       data,