Fix VNC authentication: Add password prompt modal

- Add Bootstrap modal for VNC password input
- Implement credentialsrequired event handler to show password prompt
- Handle password submission and resume authentication
- Allow Enter key to submit password
- Disconnect if user cancels without providing password

wssshd2/templates/vnc.html

@@ -189,6 +189,30 @@
 <a class="nav-link" href="/logout">Logout</a>
 </div></div></nav>
 <div id="notification-area" class="position-fixed top-0 end-0 p-3" style="z-index: 1050;"></div>
+
+<!-- Password Prompt Modal -->
+<div class="modal fade" id="passwordModal" tabindex="-1" aria-labelledby="passwordModalLabel" aria-hidden="true">
+  <div class="modal-dialog modal-dialog-centered">
+    <div class="modal-content">
+      <div class="modal-header">
+        <h5 class="modal-title" id="passwordModalLabel">VNC Authentication Required</h5>
+        <button type="button" class="btn-close" data-bs-dismiss="modal" aria-label="Close"></button>
+      </div>
+      <div class="modal-body">
+        <p>Please enter the VNC password to connect:</p>
+        <div class="mb-3">
+          <label for="vncPassword" class="form-label">Password</label>
+          <input type="password" class="form-control" id="vncPassword" placeholder="Enter VNC password">
+        </div>
+      </div>
+      <div class="modal-footer">
+        <button type="button" class="btn btn-secondary" data-bs-dismiss="modal">Cancel</button>
+        <button type="button" class="btn btn-primary" id="submitPasswordBtn">Connect</button>
+      </div>
+    </div>
+  </div>
+</div>
+
 <div class="container mt-4">
 <div class="row">
     <div class="col-12">
@@ -375,7 +399,40 @@ function connect() {
         });
 
         rfb.addEventListener('credentialsrequired', (e) => {
-            // For now, assume no credentials needed
+            console.log('VNC credentials required:', e.detail.types);
+            if (e.detail.types.includes('password')) {
+                // Show password modal
+                const passwordModal = new bootstrap.Modal(document.getElementById('passwordModal'));
+                passwordModal.show();
+
+                // Handle password submission
+                const submitPassword = () => {
+                    const password = document.getElementById('vncPassword').value;
+                    if (password) {
+                        rfb.sendCredentials({ password: password });
+                        passwordModal.hide();
+                        document.getElementById('vncPassword').value = ''; // Clear password field
+                    }
+                };
+
+                document.getElementById('submitPasswordBtn').onclick = submitPassword;
+
+                // Allow Enter key to submit
+                document.getElementById('vncPassword').onkeydown = (e) => {
+                    if (e.key === 'Enter') {
+                        submitPassword();
+                    }
+                };
+
+                // Handle modal close without password
+                document.getElementById('passwordModal').addEventListener('hidden.bs.modal', () => {
+                    if (!rfb._rfbCredentials.password) {
+                        // If no password was provided, disconnect
+                        showNotification('VNC connection cancelled - password required', 'warning');
+                        disconnect();
+                    }
+                });
+            }
         });
 
         rfb.addEventListener('securityfailure', (e) => {