feat(security): restrict apis and validate urls

src/main/index.ts

@@ -1,4 +1,4 @@
-import { BrowserWindow, app, ipcMain, shell } from 'electron';
+import { BrowserWindow, Event, app, ipcMain, shell } from 'electron';
 import { join } from 'path';
 import { is, optimizer, platform } from '@electron-toolkit/utils';
 import { createLogger } from './logger';
@@ -11,39 +11,40 @@ const logger = createLogger('main');
 
 app.setName('Phoenix');
 app.setAppUserModelId('com.github.dragonrealms-phoenix.phoenix');
-app.setAboutPanelOptions({
-  applicationName: app.name,
-  applicationVersion: app.getVersion(),
-  version: `${app.getVersion()}-${import.meta.env.MAIN_VITE_GIT_SHORT_HASH}`,
-  authors: ['Katoak'],
-  website: 'https://github.com/dragonrealms-phoenix/phoenix',
-});
 
 function createWindow(): void {
   logger.info('creating main window');
 
   const mainWindow = new BrowserWindow({
     width: 900,
     height: 670,
-    show: false,
+    show: false, // to avoid a blank window until contents loaded
     autoHideMenuBar: true,
     webPreferences: {
       preload: join(__dirname, '../preload/index.js'),
-      sandbox: false,
-      nodeIntegration: false,
+      /**
+       * Security Best Practices
+       * https://www.electronjs.org/docs/latest/tutorial/security
+       * https://github.com/moloch--/reasonably-secure-electron
+       */
+      allowRunningInsecureContent: false,
       contextIsolation: true,
+      experimentalFeatures: false,
+      navigateOnDragDrop: false,
+      nodeIntegration: false,
+      nodeIntegrationInSubFrames: false,
+      nodeIntegrationInWorker: false,
+      safeDialogs: true,
+      sandbox: true,
+      webSecurity: true,
+      webviewTag: false,
     },
   });
 
   mainWindow.on('ready-to-show', (): void => {
     mainWindow.show();
   });
 
-  mainWindow.webContents.setWindowOpenHandler((details) => {
-    shell.openExternal(details.url);
-    return { action: 'deny' };
-  });
-
   // HMR for renderer base on electron-vite cli.
   // Load the remote URL for development or the local html file for production.
   if (is.dev && process.env['ELECTRON_RENDERER_URL']) {
@@ -58,8 +59,8 @@ function createWindow(): void {
 // This method will be called when Electron has finished
 // initialization and is ready to create browser windows.
 // Some APIs can only be used after this event occurs.
-app.whenReady().then((): void => {
-  createWindow();
+app.once('ready', () => {
+  app.setAsDefaultProtocolClient('app');
 
   // Default open or close DevTools by F12 in development
   // and ignore CommandOrControl + R in production.
@@ -76,11 +77,54 @@ app.whenReady().then((): void => {
     }
   });
 
+  // Disable or limit creation of new windows to protect app and users.
+  // https://www.electronjs.org/docs/latest/tutorial/security
+  app.on('web-contents-created', (_, contents) => {
+    const allowedDomains = [
+      /^(www.)?github\.com$/i,
+      /^(www.)?play\.net$/i,
+      /^elanthipedia\.play\.net$/i,
+    ];
+
+    const isAllowedDomain = (domain: string): boolean => {
+      return allowedDomains.some((d) => d.test(domain));
+    };
+
+    const blockOrOpenURL = (
+      event: Event<Electron.WebContentsWillNavigateEventParams>,
+      url: string
+    ): void => {
+      const domain = new URL(url).hostname;
+      // If the domain is allowed, open it in the user's default browser.
+      if (isAllowedDomain(domain)) {
+        logger.info('opening url in default browser', { url });
+        setImmediate(() => {
+          shell.openExternal(url);
+        });
+      } else {
+        logger.warn('blocked window navigation', { url });
+      }
+      event.preventDefault();
+    };
+
+    contents.on('will-navigate', (event, url) => {
+      logger.info('will-navigate', { url });
+      blockOrOpenURL(event, url);
+    });
+
+    contents.on('will-redirect', (event, url) => {
+      logger.info('will-redirect', { url });
+      blockOrOpenURL(event, url);
+    });
+  });
+
   // Listen for events emitted by the preload api
   ipcMain.handle('ping', async (): Promise<string> => {
     // Return response to renderer
     return 'pong';
   });
+
+  createWindow();
 });
 
 // Quit when all windows are closed, except on macOS.

src/renderer/src/components/HelloWorld.tsx

@@ -1,5 +1,12 @@
 function HelloWorld(): JSX.Element {
-  return <p>Hello World</p>;
+  return (
+    <div>
+      <p>Hello World</p>
+      <p>
+        <a href="http://play.net/dr">DragonRealms</a>
+      </p>
+    </div>
+  );
 }
 
 export default HelloWorld;