src/e2ee/sharedKeyManagement.ts

@@ -12,7 +12,7 @@ import {
   setLocalStorageItemReactive,
   useLocalStorage,
 } from "../useLocalStorage";
-import { getUrlParams } from "../UrlParams";
+import { getUrlParams, useUrlParams } from "../UrlParams";
 import { E2eeType } from "./e2eeType";
 import { useClient } from "../ClientContext";
 
@@ -57,19 +57,31 @@ const useRoomSharedKey = (
   return [setInitialValue ?? roomSharedKey, setRoomSharedKey];
 };
 
-export function getKeyForRoom(roomId: string): string | null {
-  const { roomId: urlRoomId, password } = getUrlParams();
-  if (roomId !== urlRoomId)
+/**
+ * The shared key for a room, preferring one supplied in the parameters Element
+ * Call was started with over whatever is in local storage.
+ */
+function keyForRoom(
+  roomId: string,
+  paramsRoomId: string | null,
+  password: string | null,
+): string | null {
+  if (roomId !== paramsRoomId)
     logger.warn(
       "requested key for a roomId which is not the current call room id (from the URL)",
       roomId,
-      urlRoomId,
+      paramsRoomId,
     );
   return (
     password ?? localStorage.getItem(getRoomSharedKeyLocalStorageKey(roomId))
   );
 }
 
+export function getKeyForRoom(roomId: string): string | null {
+  const { roomId: paramsRoomId, password } = getUrlParams();
+  return keyForRoom(roomId, paramsRoomId, password);
+}
+
 export type Unencrypted = { kind: E2eeType.NONE };
 export type SharedSecret = { kind: E2eeType.SHARED_KEY; secret: string };
 export type PerParticipantE2EE = { kind: E2eeType.PER_PARTICIPANT };
@@ -77,10 +89,15 @@ export type EncryptionSystem = Unencrypted | SharedSecret | PerParticipantE2EE;
 
 export function useRoomEncryptionSystem(roomId: string): EncryptionSystem {
   const { client } = useClient();
+  const { roomId: paramsRoomId, password } = useUrlParams();
 
   const [storedPassword] = useRoomSharedKey(
+    // TODO: this passes an already-prefixed key where a room ID is expected, so
+    // the local storage key ends up prefixed twice and never matches what
+    // saveKeyForRoom writes. Preserved as-is here to keep this commit a pure
+    // refactor; the reactive read is effectively dead until it is fixed.
     getRoomSharedKeyLocalStorageKey(roomId),
-    getKeyForRoom(roomId) ?? undefined,
+    keyForRoom(roomId, paramsRoomId, password) ?? undefined,
   );
 
   const room = client?.getRoom(roomId);