what is the Best practice for token expiration - Use received token expiry or create and configure JWT expiry?

Question

I'm implementing a Single Sign-On (SSO) process using SAML. I'm trying to determine the best practice for handling token expiration.

Option 1: Use the expiration time included in the received SAML token.

Option 2: Create a new JWT token and set its own expiration time.

I've searched for existing answers on Stackoverflow and other forums, but I haven't found a clear consensus on the best practice for handling SAML token expiration in an SSO context. Any insights or recommendations would be greatly appreciated.

Answer 1

In the context of Single Sign-On (SSO) using SAML, the best practice for handling token expiration typically depends on the specifics of your use case and the requirements of your application. However, here are some considerations for both options:

Option 1: Use the expiration time included in the received SAML token.

Pros:

1. Standardized Approach: SAML tokens usually come with a built-in expiration timestamp. Relying on this expiration time follows the SAML standard and is a widely accepted practice.
2. Reduced Complexity: You don't need to manage and synchronize multiple expiration times across different tokens.

Cons:

1. Limited Control: The expiration time is set by the Identity Provider (IdP). If your application has more stringent requirements or needs to enforce a specific session duration, this approach might not provide enough flexibility.

Option 2: Create a new JWT token and set its own expiration time.

Pros:

1. Flexibility: You have control over the expiration time of the JWT token, allowing you to customize session durations based on your application's specific requirements.
2. Consistent Session Handling: If your application uses JWTs for other purposes, having a consistent approach to token expiration might simplify overall token management.

Cons:

1. Increased Complexity: Managing and synchronizing expiration times between the SAML token and the JWT token adds complexity. You need to handle token refresh or reauthentication when either token expires.
2. Potential Misalignment: If not properly managed, the expiration times of the SAML token and JWT token might drift, leading to unexpected behavior.

Recommendations:

1. Alignment with Standards: If your SSO solution predominantly relies on SAML and your IdP enforces reasonable expiration times, using the SAML token's expiration time is a straightforward and standard-compliant approach.

2. Hybrid Approach: Consider a hybrid approach where you use the SAML token's expiration time as a baseline but issue a JWT token for additional session management if needed.

3. User Experience: Consider the impact on user experience. Forcing users to reauthenticate too frequently can be inconvenient, while excessively long session durations might pose security risks.

4. Security Implications: Evaluate the security implications of extending session durations. Longer sessions might increase the window of opportunity for unauthorized access if a user's session is compromised.

In summary, I would say there isn't a one-size-fits-all solution, and the best approach depends on your application's specific requirements and constraints. It's often beneficial to align with established standards while considering customization based on your application's needs.