Creating a Unified Authentication Landing Page for Third-Party OAuth-Integrated Applications

In today’s digital landscape, integrating multiple third-party applications through OAuth authentication is a common requirement for many organizations. A typical scenario involves providing users a centralized entry point—such as a single subdomain—that handles authentication and seamlessly directs them to various third-party services. However, aligning this workflow with best practices and user experience considerations can sometimes be challenging.

Understanding the Objective

The primary goal is to establish a dedicated subdomain (for example, auth.example.com) serving as an authentication landing page. This page should feature login, logout, and registration options, all while acting as a gateway to multiple third-party applications that support OAuth protocols. Users should authenticate once via this page and then be guided smoothly to the respective third-party services without having to re-authenticate repeatedly.

Core Challenges

1. Centralized User Authentication: Users must authenticate through your IdP (Identity Provider) on the landing page, rather than directly on each third-party app.
2. Seamless User Flow: After authentication, users should be directed to the specific service they intend to use, leveraging OAuth flows.
3. Maintaining Security & Privacy: The process must securely handle tokens and user data in accordance with OAuth specifications and privacy standards.

Proposed Approach

1. Developing a Custom Authentication Landing Page

To meet the above objectives, design a dedicated WordPress page on a subdomain (e.g., auth.example.com). This page will serve as the user’s entry point, featuring login, logout, and signup capabilities linked to your IdP. Instead of a static page, consider implementing dynamic elements that handle OAuth redirection, session management, and user state.

1. Implementing OAuth Flows

2. User Initiates Authentication: When a user clicks “Login,” redirect them to your IdP’s OAuth authorization endpoint.

3. Handling OAuth Callback: After successful login, the IdP redirects back to your WordPress site with an authorization code.

4. Exchanging Authorization Code: Your server exchanges this code for access tokens and user information, establishing the user’s session.

5. Linking to Third-Party Applications

6. Post-Authentication Links: On the landing page, provide links or buttons to third-party applications.

7. OAuth Handshake with Third-Party Apps: When users click these links, initiate the OAuth flow with the respective third-party service, passing along any necessary tokens or user identifiers.
8. Session Persistence: Store relevant tokens securely to streamline subsequent access without repeated logins.