How to Retrieve the Client ID from an OAuth Request in Spring Authorization Server

Learn how to efficiently fetch the `client ID` and display details from an OAuth request during authentication using Spring Authorization Server.
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How to Retrieve the Client ID from an OAuth Request in Spring Authorization Server

When working with Spring Authorization Server, you may encounter scenarios where you need to access client information associated with an ongoing OAuth authentication request. A common use case is displaying a friendly name for the client during login, particularly when users are required to log in via a form. But how do you extract this client-related information from the ongoing authentication request?

In this guide, we will explore how to achieve just that by leveraging the SavedRequest feature within the session. We will break down the process into clear steps, helping you understand how to retrieve the client ID and associated client details.

Understanding the Challenge

When a user initiates an OAuth authentication request, certain parameters such as client_id are sent with the request. However, retrieving these parameters during the login process—especially outside of the authorization framework—can be tricky. This is where the importance of the SavedRequest comes into play.

Use Case

Imagine a scenario where a user attempts to log in to access a service protected by OAuth 2.0. You might want to display the service’s friendly name or brand during the login phase to enhance user experience. However, how do you access information like the client_id necessary to fetch this friendly name?

The Solution: Using SavedRequest

The SavedRequest is a utility that allows for preserving the original request, including all parameters, in the session. Here’s how you can retrieve the client name based on the client_id found in the SavedRequest.

Step-by-Step Implementation

Checking the Session: Ensure that you have access to the HTTP session where the SavedRequest is stored.

Fetching the SavedRequest: The SavedRequest contains details about the original OAuth request, including the client_id.

Retrieve Client Name: Once you have the client_id, utilize your registeredClientRepository to fetch the registered client details, including the friendly name.

Here’s a practical code snippet that demonstrates this process:

[[See Video to Reveal this Text or Code Snippet]]

Code Explanation

Check for Session: The method begins by checking if the session is not null.

Access Saved Request: It retrieves the SavedRequest from the session.

Fetch client_id: If the SavedRequest exists and contains the client_id, the code retrieves its value.

Look Up Client: It queries the registeredClientRepository for a RegisteredClient object using the client_id.

Return Client Name: If found and valid, it returns the friendly client name; otherwise, it returns null.

Conclusion

Retrieving the client ID and associated information from an ongoing OAuth authentication request is crucial for enhancing user experience in your Spring applications. By utilizing the SavedRequest, you can easily access this information and display meaningful context during authentication.

Now you can implement this solution to enrich your application's login interface with friendly client names that boost user engagement. If you have any further questions or need assistance, feel free to reach out in the comments!