adds mobileShutdown.js and POST /shutdown/ route

libraries/mobile/mobileShutdown.js

@@ -0,0 +1,51 @@
+const EXPECTED_SECRET_LENGTH = 44; // string length of base-64 encoding a 32-byte secret
+const BASE64_32BYTE_REGEX = /^[A-Za-z0-9+/]{43}=$/;
+
+/**
+ * To be able to shut down the server with POST /shutdown/ (e.g. in the mobile app),
+ * the server can be run with a secret generated by `openssl rand -base64 32`.
+ * This function validates that the given string is a base64-encoded 32-byte secret.
+ */
+function isValidShutdownSecret(secret) {
+    if (typeof secret !== 'string' || secret.length !== EXPECTED_SECRET_LENGTH) {
+        return false;
+    }
+
+    if (!BASE64_32BYTE_REGEX.test(secret)) {
+        return false;
+    }
+
+    try {
+        const decoded = Buffer.from(secret, 'base64');
+        return decoded.length === 32;
+    } catch {
+        return false;
+    }
+}
+
+/**
+ * Attempts to load the shutdown secret from process.argv[2].
+ * Returns null if invalid or missing. It's ok to omit it, but the /shutdown/ route will be disabled.
+ */
+function getShutdownSecretFromArgs() {
+    const rawSecret = process.argv[2];
+
+    if (!isValidShutdownSecret(rawSecret)) {
+        return null;
+    }
+
+    return rawSecret;
+}
+
+/**
+ * Compares the incoming request token with the expected shutdown secret.
+ */
+function verifyShutdownRequest(req, expectedSecret) {
+    const token = req.headers['x-shutdown-token'];
+    return token === expectedSecret;
+}
+
+module.exports = {
+    getShutdownSecretFromArgs,
+    verifyShutdownRequest,
+};

server.js

@@ -78,6 +78,10 @@ try {
 const _logger = require('./logger');
 const {objectsPath, beatPort, serverPort, allowSecureMode, persistToCloud} = require('./config');
 const {providedServices} = require('./services');
+const {
+    getShutdownSecretFromArgs,
+    verifyShutdownRequest,
+} = require('./libraries/mobile/mobileShutdown');
 
 const os = require('os');
 const {isLightweightMobile, isStandaloneMobile} = require('./isMobile.js');
@@ -2104,6 +2108,24 @@ function objectWebServer() {
             }
         });
 
+        // If the server args includes a 32-byte base-64 encoded secret, then enable a special /shutdown/ route
+        const SHUTDOWN_SECRET = getShutdownSecretFromArgs();
+
+        if (SHUTDOWN_SECRET) {
+            console.info('POST /shutdown/ route is enabled, with secret', SHUTDOWN_SECRET);
+            webServer.post('/shutdown/', function (req, res) {
+                if (!verifyShutdownRequest(req, SHUTDOWN_SECRET)) {
+                    return res.status(403).send('Forbidden: Invalid shutdown token');
+                }
+
+                console.info('Authorized shutdown request received');
+                res.send('Shutting down server...');
+                exit();
+            });
+        } else {
+            console.info('POST /shutdown/ route is disabled');
+        }
+
         webServer.get('/server/networkInterface/:activeInterface/', function (req, res) {
             services.ips.activeInterface = req.params.activeInterface;
             res.json(services.ips);