From 9126fb3f3e5e74d446200930d73432882e91894d Mon Sep 17 00:00:00 2001
From: David Baker <dave@matrix.org>
Date: Fri, 20 Oct 2023 17:31:15 +0100
Subject: [PATCH] Fix key format on the wire to be base64

---
 package.json                  |  2 +-
 src/e2ee/matrixKeyProvider.ts |  6 +++---
 src/matrix-utils.ts           | 20 ++------------------
 yarn.lock                     |  4 ++--
 4 files changed, 8 insertions(+), 24 deletions(-)

diff --git a/package.json b/package.json
index 59ecf93e..d68729f3 100644
--- a/package.json
+++ b/package.json
@@ -58,7 +58,7 @@
     "i18next-http-backend": "^2.0.0",
     "livekit-client": "^1.12.3",
     "lodash": "^4.17.21",
-    "matrix-js-sdk": "github:matrix-org/matrix-js-sdk#9a42886e26267e0e4508bb4f40f4ab4de6db9a2e",
+    "matrix-js-sdk": "github:matrix-org/matrix-js-sdk#4120641b3d3983733044967812e475bc3610d1e7",
     "matrix-widget-api": "^1.3.1",
     "normalize.css": "^8.0.1",
     "pako": "^2.0.4",
diff --git a/src/e2ee/matrixKeyProvider.ts b/src/e2ee/matrixKeyProvider.ts
index fcef3d8e..73b788d8 100644
--- a/src/e2ee/matrixKeyProvider.ts
+++ b/src/e2ee/matrixKeyProvider.ts
@@ -14,7 +14,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-import { BaseKeyProvider, createKeyMaterialFromString } from "livekit-client";
+import { BaseKeyProvider, createKeyMaterialFromBuffer } from "livekit-client";
 import { logger } from "matrix-js-sdk/src/logger";
 import {
   MatrixRTCSession,
@@ -56,12 +56,12 @@ export class MatrixKeyProvider extends BaseKeyProvider {
   }
 
   private onEncryptionKeyChanged = async (
-    encryptionKey: string,
+    encryptionKey: Uint8Array,
     encryptionKeyIndex: number,
     participantId: string,
   ): Promise<void> => {
     this.onSetEncryptionKey(
-      await createKeyMaterialFromString(encryptionKey),
+      await createKeyMaterialFromBuffer(encryptionKey),
       participantId,
       encryptionKeyIndex,
     );
diff --git a/src/matrix-utils.ts b/src/matrix-utils.ts
index 52c55959..7c0966fb 100644
--- a/src/matrix-utils.ts
+++ b/src/matrix-utils.ts
@@ -28,6 +28,7 @@ import {
   GroupCallIntent,
   GroupCallType,
 } from "matrix-js-sdk/src/webrtc/groupCall";
+import { secureRandomBase64 } from "matrix-js-sdk/src/randomstring";
 
 import type { MatrixClient } from "matrix-js-sdk/src/client";
 import type { Room } from "matrix-js-sdk/src/models/room";
@@ -73,23 +74,6 @@ function waitForSync(client: MatrixClient): Promise<void> {
   });
 }
 
-function secureRandomString(entropyBytes: number): string {
-  const key = new Uint8Array(entropyBytes);
-  crypto.getRandomValues(key);
-  // encode to base64url as this value goes into URLs
-  // base64url is just base64 with thw two non-alphanum characters swapped out for
-  // ones that can be put in a URL without encoding. Browser JS has a native impl
-  // for base64 encoding but only a string (there isn't one that takes a UInt8Array
-  // yet) so just use the built-in one and convert, replace the chars and strip the
-  // padding from the end (otherwise we'd need to pull in another dependency).
-  return btoa(
-    key.reduce((acc, current) => acc + String.fromCharCode(current), ""),
-  )
-    .replace("+", "-")
-    .replace("/", "_")
-    .replace(/=*$/, "");
-}
-
 /**
  * Initialises and returns a new standalone Matrix Client.
  * If true is passed for the 'restore' parameter, a check will be made
@@ -363,7 +347,7 @@ export async function createRoom(
 
   let password;
   if (e2ee) {
-    password = secureRandomString(16);
+    password = secureRandomBase64(16);
     setLocalStorageItem(
       getRoomSharedKeyLocalStorageKey(result.room_id),
       password,
diff --git a/yarn.lock b/yarn.lock
index 253e6e1d..3d2988ee 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -7042,9 +7042,9 @@ matrix-events-sdk@0.0.1:
   resolved "https://registry.yarnpkg.com/matrix-events-sdk/-/matrix-events-sdk-0.0.1.tgz#c8c38911e2cb29023b0bbac8d6f32e0de2c957dd"
   integrity sha512-1QEOsXO+bhyCroIe2/A5OwaxHvBm7EsSQ46DEDn8RBIfQwN5HWBpFvyWWR4QY0KHPPnnJdI99wgRiAl7Ad5qaA==
 
-"matrix-js-sdk@github:matrix-org/matrix-js-sdk#9a42886e26267e0e4508bb4f40f4ab4de6db9a2e":
+"matrix-js-sdk@github:matrix-org/matrix-js-sdk#4120641b3d3983733044967812e475bc3610d1e7":
   version "29.0.0"
-  resolved "https://codeload.github.com/matrix-org/matrix-js-sdk/tar.gz/9a42886e26267e0e4508bb4f40f4ab4de6db9a2e"
+  resolved "https://codeload.github.com/matrix-org/matrix-js-sdk/tar.gz/4120641b3d3983733044967812e475bc3610d1e7"
   dependencies:
     "@babel/runtime" "^7.12.5"
     "@matrix-org/matrix-sdk-crypto-wasm" "^2.0.0"