From fa5b014abec5f71f8c2f8ef3ea46742011547cf8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C5=A0imon=20Brandner?= <simon.bra.ag@gmail.com>
Date: Tue, 22 Aug 2023 17:23:29 +0200
Subject: [PATCH] E2EE for embeded mode
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Signed-off-by: Šimon Brandner <simon.bra.ag@gmail.com>
---
 src/e2ee/matrixKeyProvider.ts | 81 +++++++++++++++++++++++++++++++++++
 src/livekit/useLiveKit.ts     |  5 ++-
 src/room/InCallView.tsx       |  1 +
 3 files changed, 86 insertions(+), 1 deletion(-)
 create mode 100644 src/e2ee/matrixKeyProvider.ts

diff --git a/src/e2ee/matrixKeyProvider.ts b/src/e2ee/matrixKeyProvider.ts
new file mode 100644
index 00000000..2d0bc1a8
--- /dev/null
+++ b/src/e2ee/matrixKeyProvider.ts
@@ -0,0 +1,81 @@
+/*
+Copyright 2023 New Vector Ltd
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import { logger } from "@sentry/utils";
+import {
+  BaseKeyProvider,
+  KeyProviderOptions,
+  createKeyMaterialFromString,
+} from "livekit-client";
+import { CallMembership } from "matrix-js-sdk/src/matrixrtc/CallMembership";
+import {
+  MatrixRTCSession,
+  MatrixRTCSessionEvent,
+} from "matrix-js-sdk/src/matrixrtc/MatrixRTCSession";
+
+export class MatrixKeyProvider extends BaseKeyProvider {
+  constructor(
+    private rtcSession: MatrixRTCSession,
+    keyProviderOptions: Partial<KeyProviderOptions> = {}
+  ) {
+    super(keyProviderOptions);
+
+    const encryptionKey = this.rtcSession.activeEncryptionKey;
+    if (!encryptionKey) {
+      throw new Error(
+        "MatrixKeyProvider requires the given MatrixRTCSession to have an activeEncryptionKey"
+      );
+    }
+
+    this.rtcSession.on(
+      MatrixRTCSessionEvent.MembershipsChanged,
+      this.onMemberShipsChanged
+    );
+    this.rtcSession.on(
+      MatrixRTCSessionEvent.ActiveEncryptionKeyChanged,
+      this.onEncryptionKeyChanged
+    );
+
+    this.onEncryptionKeyChanged(encryptionKey);
+    this.onMemberShipsChanged([], this.rtcSession.memberships);
+  }
+
+  private onEncryptionKeyChanged = async (key: string) => {
+    this.onSetEncryptionKey(await createKeyMaterialFromString(key), undefined);
+  };
+
+  private onMemberShipsChanged = async (
+    _: CallMembership[],
+    newMemberships: CallMembership[]
+  ) => {
+    for (const membership of newMemberships) {
+      const participantId = `${membership.member.userId}:${membership.deviceId}`;
+      const encryptionKey = await membership.getActiveEncryptionKey();
+
+      if (!encryptionKey) {
+        logger.warn(
+          `Participant ${participantId} did not share a key over Matrix`
+        );
+        continue;
+      }
+
+      this.onSetEncryptionKey(
+        await createKeyMaterialFromString(encryptionKey),
+        participantId
+      );
+    }
+  };
+}
diff --git a/src/livekit/useLiveKit.ts b/src/livekit/useLiveKit.ts
index 1f5704b3..5adccee1 100644
--- a/src/livekit/useLiveKit.ts
+++ b/src/livekit/useLiveKit.ts
@@ -17,7 +17,6 @@ limitations under the License.
 import {
   ConnectionState,
   E2EEOptions,
-  ExternalE2EEKeyProvider,
   Room,
   RoomOptions,
   setLogLevel,
@@ -26,6 +25,8 @@ import { useLiveKitRoom } from "@livekit/components-react";
 import { useEffect, useMemo, useRef } from "react";
 import E2EEWorker from "livekit-client/e2ee-worker?worker";
 import { logger } from "matrix-js-sdk/src/logger";
+import { MatrixRTCSession } from "matrix-js-sdk/src/matrixrtc/MatrixRTCSession";
+import { ExternalE2EEKeyProvider } from "livekit-client/dist/src/e2ee/KeyProvider";
 
 import { defaultLiveKitOptions } from "./options";
 import { SFUConfig } from "./openIDSFU";
@@ -39,6 +40,7 @@ import {
   ECConnectionState,
   useECConnectionState,
 } from "./useECConnectionState";
+import { MatrixKeyProvider } from "../e2ee/matrixKeyProvider";
 
 export type E2EEConfig = {
   sharedKey: string;
@@ -53,6 +55,7 @@ interface UseLivekitResult {
 
 export function useLiveKit(
   muteStates: MuteStates,
+  rtcSession: MatrixRTCSession,
   sfuConfig?: SFUConfig,
   e2eeConfig?: E2EEConfig
 ): UseLivekitResult {
diff --git a/src/room/InCallView.tsx b/src/room/InCallView.tsx
index 76cb7c07..22723a08 100644
--- a/src/room/InCallView.tsx
+++ b/src/room/InCallView.tsx
@@ -95,6 +95,7 @@ export function ActiveCall(props: ActiveCallProps) {
   const sfuConfig = useOpenIDSFU(props.client, props.rtcSession);
   const { livekitRoom, connState } = useLiveKit(
     props.muteStates,
+    props.rtcSession,
     sfuConfig,
     props.e2eeConfig
   );