[FIX] Differ to Last Session Authenticated (#3667)

* [FIX] Differ to Last Session Authenticated

* Added timesync

* [FIX] Differ to Last Session Authenticated

* Added timesync

* timesync tweaks

* refactor diffLastLocalSession and saveLastLocalAuthentication

* did a race

* Update comment in app/utils/localAuthentication.ts

Co-authored-by: Diego Mello <diegolmello@gmail.com>

* refactor getServerTimeSync and when use this route

* tweak

Co-authored-by: Diego Mello <diegolmello@gmail.com>

app/lib/rocketchat/services/getServerTimeSync.ts

+import RNFetchBlob from 'rn-fetch-blob';
+
+export const getServerTimeSync = async (server: string) => {
+	try {
+		const response = await Promise.race([
+			RNFetchBlob.fetch('GET', `${server}/_timesync`),
+			new Promise<undefined>(res => setTimeout(res, 2000))
+		]);
+		if (response?.data) {
+			return parseInt(response.data);
+		}
+		return null;
+	} catch {
+		return null;
+	}
+};

app/utils/localAuthentication.ts

 import * as LocalAuthentication from 'expo-local-authentication';
-import moment from 'moment';
 import RNBootSplash from 'react-native-bootsplash';
 import AsyncStorage from '@react-native-community/async-storage';
 import { sha256 } from 'js-sha256';
+import moment from 'moment';
 
 import UserPreferences from '../lib/userPreferences';
 import { store } from '../lib/auxStore';
 import database from '../lib/database';
+import { getServerTimeSync } from '../lib/rocketchat/services/getServerTimeSync';
 import {
 	ATTEMPTS_KEY,
 	BIOMETRY_ENABLED_KEY,
@@ -21,16 +22,25 @@ import { TServerModel } from '../definitions/IServer';
 import EventEmitter from './events';
 import { isIOS } from './deviceInfo';
 
-export const saveLastLocalAuthenticationSession = async (server: string, serverRecord?: TServerModel): Promise<void> => {
+export const saveLastLocalAuthenticationSession = async (
+	server: string,
+	serverRecord?: TServerModel,
+	timesync?: number | null
+): Promise<void> => {
+	if (!timesync) {
+		timesync = new Date().getTime();
+	}
+
 	const serversDB = database.servers;
 	const serversCollection = serversDB.get('servers');
 	await serversDB.write(async () => {
 		try {
 			if (!serverRecord) {
-				serverRecord = (await serversCollection.find(server)) as TServerModel;
+				serverRecord = await serversCollection.find(server);
 			}
+			const time = timesync || 0;
 			await serverRecord.update(record => {
-				record.lastLocalAuthenticatedSession = new Date();
+				record.lastLocalAuthenticatedSession = new Date(time);
 			});
 		} catch (e) {
 			// Do nothing
@@ -103,6 +113,9 @@ export const localAuthenticate = async (server: string): Promise<void> => {
 
 	// if screen lock is enabled
 	if (serverRecord?.autoLock) {
+		// Get time from server
+		const timesync = await getServerTimeSync(server);
+
 		// Make sure splash screen has been hidden
 		try {
 			await RNBootSplash.hide();
@@ -116,10 +129,10 @@ export const localAuthenticate = async (server: string): Promise<void> => {
 		// `checkHasPasscode` results newPasscode = true if a passcode has been set
 		if (!result?.newPasscode) {
 			// diff to last authenticated session
-			const diffToLastSession = moment().diff(serverRecord?.lastLocalAuthenticatedSession, 'seconds');
+			const diffToLastSession = moment(timesync).diff(serverRecord?.lastLocalAuthenticatedSession, 'seconds');
 
-			// if last authenticated session is older than configured auto lock time, authentication is required
-			if (diffToLastSession >= serverRecord.autoLockTime!) {
+			// if it was not possible to get `timesync` from server or the last authenticated session is older than the configured auto lock time, authentication is required
+			if (!timesync || (serverRecord?.autoLockTime && diffToLastSession >= serverRecord.autoLockTime)) {
 				// set isLocalAuthenticated to false
 				store.dispatch(setLocalAuthenticated(false));
 
@@ -141,7 +154,7 @@ export const localAuthenticate = async (server: string): Promise<void> => {
 		}
 
 		await resetAttempts();
-		await saveLastLocalAuthenticationSession(server, serverRecord);
+		await saveLastLocalAuthenticationSession(server, serverRecord, timesync);
 	}
 };