Are you tired of scratching your head, trying to figure out why certain claims are missing from the OIDC UserInfo response in Keycloak? Well, wonder no more! In this article, we’ll delve into the inner workings of Keycloak and explore the exact process that determines which claims make the cut. Buckle up, and let’s dive into the fascinating world of claims and OIDC!
The OIDC UserInfo Endpoint: A Quick Refresher
Before we dive into the nitty-gritty of claim selection, let’s quickly review what the OIDC UserInfo endpoint is all about. The UserInfo endpoint is a crucial part of the OpenID Connect (OIDC) protocol, which allows clients to retrieve additional information about the authenticated user. This endpoint returns a JSON response containing claims about the user, such as their name, email, and profile information.
Keycloak’s Role in OIDC UserInfo
In a Keycloak-based OIDC setup, the authentication server (Keycloak) acts as the OIDC provider. When a client (e.g., a web application) requests access to the UserInfo endpoint, Keycloak generates a response containing the requested claims. But have you ever wondered how Keycloak decides which claims to include in the response?
The Claim Selection Process: A Step-by-Step Guide
Now that we’ve set the stage, let’s walk through the exact process Keycloak follows to determine which claims to include in the OIDC UserInfo response:
- Client Configuration: The first step in the claim selection process is to examine the client configuration. Keycloak checks the client’s settings to see which claims are requested and which ones are mandatory.
- User Profile: Next, Keycloak retrieves the user’s profile information from the database. This includes attributes like the user’s name, email, and other custom attributes.
- Mappers: Keycloak uses mappers to map user attributes to OIDC claims. Mappers define how user attributes are transformed into OIDC claims. For example, a mapper might map the user’s email address to the “email” claim.
- Protocol Mappers: Protocol mappers are used to map OIDC claims to specific protocol-related claims (e.g., “acr_values” or “auth_time”). These mappers are used in addition to the standard mappers.
- Claim Definition: Keycloak checks the claim definition to determine which claims are required, optional, or disabled. Claim definitions are configured in the Keycloak console.
- Claim Filtering: Keycloak applies claim filtering to remove any unwanted claims from the response. Filtering can be based on various criteria, such as the claim’s value or the user’s permissions.
- Claim Aggregation: In some cases, Keycloak may aggregate multiple claims into a single claim. For example, aggregating multiple email addresses into a single “email” claim.
- Final Filtering: The final step is to apply any additional filtering or transformations to the claims before returning the OIDC UserInfo response.
Claim Mapping: The Unsung Hero of OIDC UserInfo
Claim mapping is a critical component of the claim selection process. Mappers define how user attributes are transformed into OIDC claims. Let’s take a closer look at the different types of mappers and how they work:
Mapper Types
- Attribute Mapper: Maps user attributes to OIDC claims. For example, mapping the user’s email address to the “email” claim.
- Hardcoded Mapper: Returns a hardcoded value for a specific claim. For example, always returning “true” for the “active” claim.
- Aggregate Mapper: Aggregates multiple values into a single claim. For example, aggregating multiple email addresses into a single “email” claim.
- Script Mapper: Uses a custom script to transform user attributes into OIDC claims. For example, using a script to concatenate the user’s first and last names into a single “fullName” claim.
Mapper Configuration
To configure mappers in Keycloak, you can use the Keycloak console or create a custom mapper implementation using the Keycloak API. Here’s an example of how you might configure an attribute mapper:
<mapper>
<mapper>
<name>email</name>
<mapper>attribute</mapper>
<user.attribute>email</user.attribute>
<claim.name>email</claim.name>
</mapper>
</mapper>
Best Practices for OIDC UserInfo Claims
Now that we’ve explored the claim selection process and claim mapping, let’s discuss some best practices for OIDC UserInfo claims:
Minimize Claim Overload
Avoid overloading the OIDC UserInfo response with too many claims. This can lead to performance issues and make it harder to manage claims. Only include the claims that are necessary for your application.
Use Standard Claims
Stick to standard OIDC claims whenever possible. This ensures compatibility with different OIDC providers and reduces the risk of claim-related issues.
Use Custom Claims Judiciously
Custom claims can be useful, but use them sparingly. Make sure you understand the implications of using custom claims and follow best practices for claim naming and definition.
Test Your Claims
Thoroughly test your OIDC UserInfo claims to ensure they are being returned correctly and are in the expected format.
Conclusion
In conclusion, Keycloak’s claim selection process for OIDC UserInfo is a complex, yet powerful mechanism that allows you to fine-tune the claims returned in the response. By understanding how Keycloak decides which claims to include, you can optimize your OIDC setup and ensure a seamless user experience.
Remember to keep your claims concise, use standard claims whenever possible, and test your claims thoroughly. With these best practices in mind, you’ll be well on your way to mastering OIDC UserInfo claims in Keycloak!
Claim Selection Step | Description |
---|---|
Client Configuration | Examine client settings to determine requested and mandatory claims. |
User Profile | Retrieve user profile information from the database. |
Mappers | Map user attributes to OIDC claims using mappers. |
Protocol Mappers | Map OIDC claims to protocol-related claims. |
Claim Definition | Determine which claims are required, optional, or disabled. |
Claim Filtering | Apply filtering to remove unwanted claims. |
Claim Aggregation | Aggregate multiple claims into a single claim. |
Final Filtering | Apply additional filtering or transformations to the claims. |
By following the guidelines outlined in this article, you’ll be able to unlock the full potential of OIDC UserInfo claims in Keycloak and provide a more seamless user experience for your application users.
Here are the 5 Q&As about “How does Keycloak decide what claims will be included in OidcUserInfo after successful login?”
Frequently Asked Question
Get answers to the most pressing questions about Keycloak’s OIDC userinfo claims!
What is the primary source of claims for OIDC userinfo in Keycloak?
The primary source of claims for OIDC userinfo in Keycloak is the user’s profile information. Keycloak fetches the user’s profile data from the underlying user storage, such as a database or LDAP, and includes the requested claims in the OIDC userinfo response.
How does Keycloak determine which claims to include in the OIDC userinfo response?
Keycloak includes claims in the OIDC userinfo response based on the configuration of the OIDC client and the user’s profile information. The OIDC client can specify which claims it needs, and Keycloak will include those claims in the response if they are available in the user’s profile.
Can I customize the claims included in the OIDC userinfo response?
Yes, you can customize the claims included in the OIDC userinfo response by configuring the OIDC client in Keycloak. You can specify which claims are required, optional, or excluded, and Keycloak will include or exclude them accordingly.
How does Keycloak handle claims that are not available in the user’s profile?
If a claim is not available in the user’s profile, Keycloak will not include it in the OIDC userinfo response. However, you can configure Keycloak to return a default value or an error message if a claim is not available.
Are there any security considerations for including claims in the OIDC userinfo response?
Yes, including claims in the OIDC userinfo response can have security implications. You should only include claims that are necessary for your application, and ensure that sensitive information is not included in the response. Additionally, you should configure Keycloak to use a secure protocol, such as HTTPS, to protect the userinfo response.