WebAuthn & iframes Integration for Cross-Origin Authentication

Introduction: Leveraging Passkeys in iframes

Passkeys offer a superior solution for user authentication, enhancing both security and user experience. A critical aspect of modern web development involves using iframes to embed content from various sources. This article explores how to effectively integrate passkeys within iframes, focusing on cross-origin iframes, to create a seamless login experience.

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Types of iframes and Their Roles

Understanding the different types of iframes is essential for implementing passkeys effectively. Here are the primary types:

1. Basic iframe: Embeds content from another URL within the current page.
2. Responsive iframe: Adjusts its size based on the screen or container, ensuring a good appearance on all devices.
3. Secure iframe (Sandboxed iframe): Restricts actions within the iframe for enhanced security.
4. Cross-Origin iframe: Embeds content from a different domain, often used for integrating third-party services like payment gateways.

How iframes Support Passkeys

Integrating passkeys within iframes introduces both capabilities and constraints. The Web Authentication API, crucial for passkeys, historically had limitations with cross-origin iframes due to security concerns. Recent advancements, however, have made it possible to perform both registration and authentication within cross-origin iframes under certain conditions.

Login with Passkeys in Cross-Origin iframes

Login operations via cross-origin iframes are now supported across most major browsers, making it feasible to authenticate users seamlessly without redirects or pop-ups.

Create Passkeys in Cross-Origin iframes

While login operations are broadly supported, creating passkeys in cross-origin iframes is still catching up in browser support. Chrome, Firefox, and Safari have begun to support this feature, with more comprehensive support expected as WebAuthn Level 3 specification is adopted by all major browsers by the end of 2024.

Use Cases for Passkeys in iframes

Two significant use cases highlight the importance of passkeys in cross-origin iframes:

1. Federated Identity: Organizations with multiple domains can allow users to log in across different sites using a single passkey, simplifying user management and enhancing security.
2. Payments: Seamless payment processes can be achieved by integrating bank authentication within a merchant's website through cross-origin iframes, enhancing user experience and security. eee ## Benefits of Using Passkeys in iframes

Embedding passkeys within iframes offers several advantages:

• Enhanced User Experience: Eliminates the need for pop-ups or redirects, providing a smoother, less disruptive user experience.
• Improved Security: Ensures secure transactions and user verification across different domains.

Step-by-Step Guide to Implementing Passkeys in iframes

To implement passkeys in iframes effectively, follow these steps:

• Define Allow Attribute: Configure the iframe to allow publickey-credentials-get and publickey-credentials-create.

<iframe src="https://passkeys.eu" allow="publickey-credentials-get; publickey-credentials-create"></iframe>

• Set Permission Policy: Include the relevant Permissions-Policy in your HTTP response headers.

Permissions-Policy: publickey-credentials-get=*, publickey-credentials-create=*

• Handle User Activation: Ensure that the iframe content requires a user action to trigger authentication.

document.getElementById('loginPasskeyButton').addEventListener('click', async () => {
    try {
        const publicKeyCredentialRequestOptions = { /* Configuration options */ };
        const credential = await navigator.credentials.get({ publicKey: publicKeyCredentialRequestOptions });
        // Handle the created credential
    } catch (err) {
        console.error('Error authenticating via passkey:', err);
    }
});

• Example Implementation: Use a sample HTML and JavaScript setup to integrate passkeys within a cross-origin iframe.

Common Challenges and Solutions

1. Permission Policy Configuration: Ensure correct settings for allow attributes and HTTP headers.
2. Browser Compatibility: Test across multiple browsers and implement specific fixes as needed.
3. Cross-Origin iframe Issues with Safari: Be aware of Safari's limitations with cross-origin iframes and avoid third-party cookies.

Conclusion

Integrating passkeys within iframes enhances security and user experience, offering a seamless authentication process. By understanding the types of iframes and following a structured implementation guide, developers can leverage this technology effectively.
Find out more on Passkeys & iframes: How to Create & Login with a Passkey.