From bcf054fd0868e26a23b64fc47bebfe96e0ec3210 Mon Sep 17 00:00:00 2001
From: Laurent Cozic <laurent22@users.noreply.github.com>
Date: Sun, 24 Sep 2023 16:26:01 +0100
Subject: [PATCH] All: Resolves #6978: Improved handling of invalid sync info

---
 .../synchronizer/syncInfoUtils.test.ts        | 25 +++++++++++++++++--
 .../services/synchronizer/syncInfoUtils.ts    | 17 +++++++++++--
 2 files changed, 38 insertions(+), 4 deletions(-)

diff --git a/packages/lib/services/synchronizer/syncInfoUtils.test.ts b/packages/lib/services/synchronizer/syncInfoUtils.test.ts
index 559684d48..53984df99 100644
--- a/packages/lib/services/synchronizer/syncInfoUtils.test.ts
+++ b/packages/lib/services/synchronizer/syncInfoUtils.test.ts
@@ -1,6 +1,6 @@
-import { afterAllCleanUp, setupDatabaseAndSynchronizer, switchClient, encryptionService, msleep } from '../../testing/test-utils';
+import { afterAllCleanUp, setupDatabaseAndSynchronizer, logger, switchClient, encryptionService, msleep } from '../../testing/test-utils';
 import MasterKey from '../../models/MasterKey';
-import { masterKeyEnabled, mergeSyncInfos, setMasterKeyEnabled, SyncInfo, syncInfoEquals } from './syncInfoUtils';
+import { localSyncInfo, masterKeyEnabled, mergeSyncInfos, saveLocalSyncInfo, setMasterKeyEnabled, SyncInfo, syncInfoEquals } from './syncInfoUtils';
 
 describe('syncInfoUtils', () => {
 
@@ -154,4 +154,25 @@ describe('syncInfoUtils', () => {
 		expect(mergeSyncInfos(syncInfo1, syncInfo2).activeMasterKeyId).toBe('1');
 	});
 
+	it('should fix the sync info if it contains invalid data', async () => {
+		logger.enabled = false;
+
+		const syncInfo = new SyncInfo();
+		syncInfo.masterKeys = [{
+			id: '1',
+			content: 'content1',
+			hasBeenUsed: true,
+			enabled: 0,
+		}];
+		syncInfo.activeMasterKeyId = '2';
+
+		saveLocalSyncInfo(syncInfo);
+
+		const loaded = localSyncInfo();
+		expect(loaded.activeMasterKeyId).toBe('');
+		expect(loaded.masterKeys.length).toBe(1);
+
+		logger.enabled = true;
+	});
+
 });
diff --git a/packages/lib/services/synchronizer/syncInfoUtils.ts b/packages/lib/services/synchronizer/syncInfoUtils.ts
index 863c18e68..f42a39e37 100644
--- a/packages/lib/services/synchronizer/syncInfoUtils.ts
+++ b/packages/lib/services/synchronizer/syncInfoUtils.ts
@@ -1,3 +1,4 @@
+import Logger from '@joplin/utils/Logger';
 import { FileApi } from '../../file-api';
 import JoplinDatabase from '../../JoplinDatabase';
 import Setting from '../../models/Setting';
@@ -6,6 +7,8 @@ import { PublicPrivateKeyPair } from '../e2ee/ppk';
 import { MasterKeyEntity } from '../e2ee/types';
 const fastDeepEqual = require('fast-deep-equal');
 
+const logger = Logger.create('syncInfoUtils');
+
 export interface SyncInfoValueBoolean {
 	value: boolean;
 	updatedTime: number;
@@ -75,15 +78,25 @@ export async function fetchSyncInfo(api: FileApi): Promise<SyncInfo> {
 		if (oldVersion) output = { version: 1 };
 	}
 
-	return new SyncInfo(JSON.stringify(output));
+	return fixSyncInfo(new SyncInfo(JSON.stringify(output)));
 }
 
 export function saveLocalSyncInfo(syncInfo: SyncInfo) {
 	Setting.setValue('syncInfoCache', syncInfo.serialize());
 }
 
+const fixSyncInfo = (syncInfo: SyncInfo) => {
+	if (syncInfo.activeMasterKeyId) {
+		if (!syncInfo.masterKeys || !syncInfo.masterKeys.find(mk => mk.id === syncInfo.activeMasterKeyId)) {
+			logger.warn(`Sync info is using a non-existent key as the active key - clearing it: ${syncInfo.activeMasterKeyId}`);
+			syncInfo.activeMasterKeyId = '';
+		}
+	}
+	return syncInfo;
+};
+
 export function localSyncInfo(): SyncInfo {
-	return new SyncInfo(Setting.value('syncInfoCache'));
+	return fixSyncInfo(new SyncInfo(Setting.value('syncInfoCache')));
 }
 
 export function localSyncInfoFromState(state: State): SyncInfo {