ElementR: report invalid keys rather than failing to restore from bac…

…kup (#4006)

* rust-crypto: allow reporting failures when restoring keys

* add test and catch more invalid keys

* remove checks for room_id and session_id as they are guaranteed to be set

* remove obsolete comment

spec/unit/rust-crypto/rust-crypto.spec.ts

@@ -46,7 +46,7 @@ import {
 } from "../../../src";
 import { mkEvent } from "../../test-utils/test-utils";
 import { CryptoBackend } from "../../../src/common-crypto/CryptoBackend";
-import { IEventDecryptionResult } from "../../../src/@types/crypto";
+import { IEventDecryptionResult, IMegolmSessionData } from "../../../src/@types/crypto";
 import { OutgoingRequestProcessor } from "../../../src/rust-crypto/OutgoingRequestProcessor";
 import {
     AccountDataClient,
@@ -1260,6 +1260,34 @@ describe("RustCrypto", () => {
                 },
             });
         });
+
+        it("ignores invalid keys when restoring from backup", async () => {
+            const rustCrypto = await makeTestRustCrypto();
+            const olmMachine: OlmMachine = rustCrypto["olmMachine"];
+
+            await olmMachine.enableBackupV1(
+                (testData.SIGNED_BACKUP_DATA.auth_data as Curve25519AuthData).public_key,
+                testData.SIGNED_BACKUP_DATA.version!,
+            );
+
+            const backup = Array.from(testData.MEGOLM_SESSION_DATA_ARRAY);
+            // in addition to correct keys, we restore an invalid key
+            backup.push({ room_id: "!roomid", session_id: "sessionid" } as IMegolmSessionData);
+            const progressCallback = jest.fn();
+            await rustCrypto.importBackedUpRoomKeys(backup, { progressCallback });
+            expect(progressCallback).toHaveBeenCalledWith({
+                total: 3,
+                successes: 0,
+                stage: "load_keys",
+                failures: 1,
+            });
+            expect(progressCallback).toHaveBeenCalledWith({
+                total: 3,
+                successes: 1,
+                stage: "load_keys",
+                failures: 1,
+            });
+        });
     });
 });
 

src/rust-crypto/backup.ts

@@ -212,15 +212,18 @@ export class RustBackupManager extends TypedEventEmitter<RustBackupCryptoEvents,
             }
             keysByRoom.get(roomId)!.set(key.session_id, key);
         }
-        await this.olmMachine.importBackedUpRoomKeys(keysByRoom, (progress: BigInt, total: BigInt): void => {
-            const importOpt: ImportRoomKeyProgressData = {
-                total: Number(total),
-                successes: Number(progress),
-                stage: "load_keys",
-                failures: 0,
-            };
-            opts?.progressCallback?.(importOpt);
-        });
+        await this.olmMachine.importBackedUpRoomKeys(
+            keysByRoom,
+            (progress: BigInt, total: BigInt, failures: BigInt): void => {
+                const importOpt: ImportRoomKeyProgressData = {
+                    total: Number(total),
+                    successes: Number(progress),
+                    stage: "load_keys",
+                    failures: Number(failures),
+                };
+                opts?.progressCallback?.(importOpt);
+            },
+        );
     }
 
     private keyBackupCheckInProgress: Promise<KeyBackupCheck | null> | null = null;