How can I Re-authenticate on Keycloak-JS

Ensuring secure access to your web applications often requires re-authenticating users, especially for sensitive operations. With keycloak-js, you can seamlessly redirect users to the Keycloak login page to refresh their session. This blog explains how to setup and implement re-authentication using concise and practical code.

Why Re-authenticate Users?

Re-authentication adds an extra layer of security by ensuring the current user is still authorized. This is especially critical for:

• Sensitive actions, such as changing passwords or accessing personal data.
• Compliance with security protocols requires periodic session validation.

How to Re-authenticate with Keycloak using 'keycloak-js'

To initiate a re-authentication flow with Keycloak in a JavaScript app using keycloak-js, follow these steps:

1. Set Up the Keycloak Instance: Ensure you have the Keycloak instance initialized.
2. Invoke the login() Method: Use keycloak.login() to redirect the user to the Keycloak login page, prompting for re-authentication.

Example:
// Initialize the Keycloak instance
const keycloak = new Keycloak({
  url: 'https://your-keycloak-server/auth',
  realm: 'your-realm',
  clientId: 'your-client-id',
});

// Re-authenticate the user
function reAuthenticate() {
  keycloak.login({
    prompt: 'login', // Forces the login prompt for re-authentication
  });
}

// Example usage
document.getElementById('reAuthButton').addEventListener('click', reAuthenticate);

Key Points to Remember

• Prompt: 'login': This option ensures the login page appears, even if the user is already logged in, enforcing re-authentication.
• Event Listener: Attach the re-authenticate function to a button or action that triggers the login prompt.

Using this approach, you can easily enforce re-authentication in your application, enhancing security where needed.