fix: address phase 1 audit findings (xss, cors, dead code)

extension/background.js

@@ -8,7 +8,6 @@ let isConnecting = false;
 let peerId = null; // initialized via getPeerId()
 let currentRoom = null;
 let lastPeersJson = null;
-let heartbeatInterval = null;
 let currentTabId = null;
 let currentTabTitle = null; // New: for Smart Matching
 let logs = [];
@@ -101,17 +100,6 @@ let forceSyncAcks = new Set();
 let forceSyncTimeout = null;
 
 // --- Storage Utils ---
-function startHeartbeat() {
-    // Session heartbeats are now handled by the chrome.alarms 'keepAlive' listener
-    // to ensure they survive Service Worker suspension in MV3.
-}
-
-function stopHeartbeat() {
-    if (heartbeatInterval) {
-        clearInterval(heartbeatInterval);
-        heartbeatInterval = null;
-    }
-}
 
 async function getPeerId() {
     const data = await chrome.storage.local.get(['peerId']);
@@ -426,8 +414,7 @@ function handleServerEvent(event, data) {
             addLog(`Joined Room: ${data.roomId}`, 'success');
             chrome.runtime.sendMessage({ type: 'PEER_UPDATE', peers: data.peers }).catch(() => {});
             
-            // Start background heartbeat
-            startHeartbeat();
+
             
             // Inform Website Bridge & Popup
             const joinStatusMsg = { type: 'JOIN_STATUS', success: true, message: 'Joined' };
@@ -656,23 +643,7 @@ chrome.alarms.onAlarm.addListener(async (alarm) => {
     }
 });
 
-setInterval(async () => {
-    await ensureState();
-    // Calling a chrome API keeps the SW alive in MV3 (Chrome 110+)
-    chrome.storage.session.get('keepAlive', () => {});
-    if (!socket || socket.readyState !== WebSocket.OPEN) {
-        connect();
-    } else if (currentRoom) {
-        // Redundant heartbeat for active SW state
-        const settings = await getSettings();
-        emit(EVENTS.PEER_STATUS, { 
-            peerId, 
-            status: 'heartbeat',
-            username: settings.username,
-            tabTitle: currentTabTitle 
-        });
-    }
-}, 30000); // every 30s
+
 
 // --- Extension Message Listeners ---
 chrome.runtime.onMessage.addListener((message, sender, sendResponse) => {
@@ -724,7 +695,7 @@ async function handleAsyncMessage(message, sender, sendResponse) {
         emit(EVENTS.LEAVE_ROOM, { peerId });
         currentRoom = null;
         currentTabId = null;
-        stopHeartbeat();
+
         updateBadgeStatus();
         
         isForceSyncInitiator = false;

server/index.js

@@ -23,7 +23,7 @@ const httpServer = createServer(app);
 // Socket.IO setup with security constraints
 const io = new Server(httpServer, {
     cors: {
-        origin: "*",
+        origin: ["https://koalasync.shik3i.net"],
         methods: ["GET", "POST"]
     },
     maxHttpBufferSize: 1024, // 1KB max per message

website/app.js

@@ -104,12 +104,26 @@ document.addEventListener('DOMContentLoaded', () => {
                             const banner = document.createElement('div');
                             banner.className = 'invite-banner';
                             banner.id = 'koala-banner';
-                            banner.innerHTML = `
-                                <div class="container" style="display:flex; justify-content:space-between; align-items:center;">
-                                    <span>🎫 Invitation for <b>${roomId}</b> detected!</span>
-                                    <a href="join.html${window.location.hash}" class="btn-banner">OPEN JOIN PAGE</a>
-                                </div>
-                            `;
+
+                            const container = document.createElement('div');
+                            container.className = 'container';
+                            container.style.cssText = 'display:flex; justify-content:space-between; align-items:center;';
+
+                            const inviteSpan = document.createElement('span');
+                            inviteSpan.appendChild(document.createTextNode('🎫 Invitation for '));
+                            const boldRoom = document.createElement('b');
+                            boldRoom.textContent = roomId;
+                            inviteSpan.appendChild(boldRoom);
+                            inviteSpan.appendChild(document.createTextNode(' detected!'));
+
+                            const joinLink = document.createElement('a');
+                            joinLink.href = 'join.html' + window.location.hash;
+                            joinLink.className = 'btn-banner';
+                            joinLink.textContent = 'OPEN JOIN PAGE';
+
+                            container.appendChild(inviteSpan);
+                            container.appendChild(joinLink);
+                            banner.appendChild(container);
                             document.body.prepend(banner);
                         }
                     }
@@ -178,7 +192,11 @@ document.addEventListener('DOMContentLoaded', () => {
                     setTimeout(() => window.close(), 3000);
                 } else {
                     banner.style.background = 'var(--error)';
-                    banner.innerHTML = `<div class="container">❌ Error: ${message}</div>`;
+                    banner.innerHTML = '';
+                    const errDiv = document.createElement('div');
+                    errDiv.className = 'container';
+                    errDiv.textContent = '❌ Error: ' + message;
+                    banner.appendChild(errDiv);
                 }
             }
         }