From 32911002d4d4296a71881fa12e09a7796b60e962 Mon Sep 17 00:00:00 2001
From: Daniel Gasienica <daniel@signal.org>
Date: Fri, 16 Mar 2018 15:32:54 -0400
Subject: [PATCH] Verify `makeAttachmentPointer` and `encryptAttachment`
 arguments

The underlying `crypto.subtle.encrypt` API requires it.
---
 libtextsecure/crypto.js      |  7 +++++++
 libtextsecure/sendmessage.js | 11 +++++++++++
 2 files changed, 18 insertions(+)

diff --git a/libtextsecure/crypto.js b/libtextsecure/crypto.js
index 24581401d0..7687e2c547 100644
--- a/libtextsecure/crypto.js
+++ b/libtextsecure/crypto.js
@@ -87,6 +87,13 @@
         },
 
         encryptAttachment: function(plaintext, keys, iv) {
+            if (!(plaintext instanceof ArrayBuffer) && !ArrayBuffer.isView(plaintext)) {
+              throw new TypeError(
+                '`plaintext` must be an `ArrayBuffer` or `ArrayBufferView`; got: ' +
+                typeof plaintext
+              );
+            }
+
             if (keys.byteLength != 64) {
                 throw new Error("Got invalid length attachment keys");
             }
diff --git a/libtextsecure/sendmessage.js b/libtextsecure/sendmessage.js
index 34072020f1..507029355c 100644
--- a/libtextsecure/sendmessage.js
+++ b/libtextsecure/sendmessage.js
@@ -116,10 +116,21 @@ function MessageSender(url, username, password, cdn_url) {
 
 MessageSender.prototype = {
     constructor: MessageSender,
+
+//  makeAttachmentPointer :: Attachment -> Promise AttachmentPointerProto
     makeAttachmentPointer: function(attachment) {
         if (typeof attachment !== 'object' || attachment == null) {
             return Promise.resolve(undefined);
         }
+
+        if (!(attachment.data instanceof ArrayBuffer) &&
+            !ArrayBuffer.isView(attachment.data)) {
+          return Promise.reject(new TypeError(
+            '`attachment.data` must be an `ArrayBuffer` or `ArrayBufferView`; got: ' +
+            typeof attachment.data
+          ));
+        }
+
         var proto = new textsecure.protobuf.AttachmentPointer();
         proto.key = libsignal.crypto.getRandomBytes(64);