API auth (untested)

app.js

@@ -27,6 +27,7 @@ const settingsApiRoute = require('./routes/api/settings');
 const passwordApiRoute = require('./routes/api/password');
 const migrationApiRoute = require('./routes/api/migration');
 const syncApiRoute = require('./routes/api/sync');
+const loginApiRoute = require('./routes/api/login');
 
 const dataDir = require('./services/data_dir');
 const sessionSecret = require('./services/session_secret');
@@ -94,6 +95,7 @@ app.use('/api/settings', settingsApiRoute);
 app.use('/api/password', passwordApiRoute);
 app.use('/api/migration', migrationApiRoute);
 app.use('/api/sync', syncApiRoute);
+app.use('/api/login', loginApiRoute);
 
 // catch 404 and forward to error handler
 app.use((req, res, next) => {

routes/api/login.js

@@ -2,17 +2,43 @@
 
 const express = require('express');
 const router = express.Router();
-const auth = require('../../services/auth');
 const sql = require('../../services/sql');
-const migration = require('../../services/migration');
+const utils = require('../../services/utils');
+const crypto = require('crypto');
 
 router.post('', async (req, res, next) => {
+    const timestamp = req.body.timestamp;
 
+    const now = utils.nowTimestamp();
 
-    res.send({
-        'db_version': parseInt(await sql.getOption('db_version')),
-        'app_db_version': migration.APP_DB_VERSION
-    });
+    if (Math.abs(timestamp - now) > 5) {
+        res.status(400);
+        res.send({ message: 'Auth request time is out of sync' });
+    }
+
+    const dbVersion = res.body.dbVersion;
+
+    if (dbVersion !== migration.APP_DB_VERSION) {
+        res.status(400);
+        res.send({ message: 'Non-matching db versions, local is version ' + migration.APP_DB_VERSION });
+    }
+
+    const documentSecret = await sql.getOption('document_secret');
+
+    const hmac = crypto.createHmac('sha256', documentSecret);
+    hmac.update(timestamp);
+    const expectedHash = hmac.digest('base64');
+
+    const givenHash = req.body.hash;
+
+    if (expectedHash !== givenHash) {
+        res.status(400);
+        res.send({ message: "Hash doesn't match" });
+    }
+
+    req.session.loggedIn = true;
+
+    res.send({});
 });
 
 module.exports = router;

services/auth.js

@@ -25,7 +25,7 @@ async function checkAuthWithoutMigration(req, res, next) {
 }
 
 async function checkApiAuth(req, res, next) {
-    if (!req.session.loggedIn && req.header("auth") !== "sync") {
+    if (!req.session.loggedIn) {
         res.sendStatus(401);
     }
 
@@ -38,7 +38,7 @@ async function checkApiAuth(req, res, next) {
 }
 
 async function checkApiAuthWithoutMigration(req, res, next) {
-    if (!req.session.loggedIn && req.header("auth") !== "sync") {
+    if (!req.session.loggedIn) {
         res.sendStatus(401);
     }
     else {

services/sync.js

@@ -7,13 +7,14 @@ const migration = require('./migration');
 const utils = require('./utils');
 const config = require('./config');
 const audit_category = require('./audit_category');
+const crypto = require('crypto');
 
 const SYNC_SERVER = config['Sync']['syncServerHost'];
 
 
 let syncInProgress = false;
 
-async function pullSync() {
+async function pullSync(cookieJar) {
     const lastSyncedPull = parseInt(await sql.getOption('last_synced_pull'));
 
     const resp = await rp({
@@ -35,7 +36,8 @@ async function pullSync() {
                 headers: {
                     auth: 'sync'
                 },
-                json: true
+                json: true,
+                jar: cookieJar
             });
 
 
@@ -53,7 +55,7 @@ async function pullSync() {
     }
 }
 
-async function pushSync() {
+async function pushSync(cookieJar) {
     const lastSyncedPush = parseInt(await sql.getOption('last_synced_push'));
     const syncStarted = utils.nowTimestamp();
 
@@ -66,7 +68,8 @@ async function pushSync() {
             auth: 'sync'
         },
         body: changed,
-        json: true
+        json: true,
+        jar: cookieJar
     });
 
     for (const noteId of changed.notes) {
@@ -79,13 +82,38 @@ async function pushSync() {
                 auth: 'sync'
             },
             body: note,
-            json: true
+            json: true,
+            jar: cookieJar
         });
     }
 
     await sql.setOption('last_synced_push', syncStarted);
 }
 
+async function login() {
+    const timestamp = utils.nowTimestamp();
+
+    const hmac = crypto.createHmac('sha256', documentSecret);
+    hmac.update(timestamp);
+    const hash = hmac.digest('base64');
+
+    const cookieJar = rp.jar();
+
+    await rp({
+        method: 'POST',
+        uri: SYNC_SERVER + '/api/login',
+        body: {
+            timestamp: timestamp,
+            dbVersion: migration.APP_DB_VERSION,
+            hash: hash
+        },
+        json: true,
+        jar: cookieJar
+    });
+
+    return cookieJar;
+}
+
 async function sync() {
     if (syncInProgress) {
         return;
@@ -98,9 +126,11 @@ async function sync() {
             return;
         }
 
-        await pushSync();
+        const cookieJar = await login();
+
+        await pushSync(cookieJar);
 
-        await pullSync();
+        await pullSync(cookieJar);
     }
     catch (e) {
         log.error("sync failed: " + e.stack);