When integrating WorkOS with Single Sign-On (SSO), careful management of key user attributes—particularly the User Principal Name (UPN)—is essential to ensure smooth authentication. One critical aspect often overlooked is the handling of case sensitivity in UPNs, which can lead to inconsistencies in password generation and user login behavior if not properly normalized.
What Can Go Wrong?
In some setups, user passwords are generated from email addresses— a requirement imposed by systems like Auth0—even when users authenticate via SSO. If UPNs are stored or processed inconsistently with regard to casing, this can cause issues such as:
Inconsistent Password Generation:
When UPNs or emails have mixed upper and lowercase characters, password generation may produce different results depending on how the case is handled. For example, a UPN likeSurnameN@lantheus.comstored with uppercase initials might generate a different password thansurnamen@lantheus.comif case isn't normalized.Login Discrepancies:
While many systems treat UPNs as case-insensitive during login, mismatched casing during password regeneration (or attribute mapping) can result in authentication failures or unpredictable behavior.Migration and Synchronization Errors:
Users migrating from other systems or with inconsistent attribute updates might have passwords stored or processed with varying cases, leading to confusing login issues.
How Should WorkOS Be Set Up?
To prevent these issues, proper configuration of user attributes in WorkOS is crucial:
Normalize User Attributes:
Ensure that key attributes such as UPN or email are transformed to a consistent case (preferably lowercase) before or during the user provisioning process. This normalization can often be configured either during provisioning workflows or via attribute mapping rules in your Identity Provider (IdP).Implement Transformation Rules in your IdP:
Use scripts or built-in features of your IdP to enforce lowercase UPNs prior to sending data to WorkOS. Not all IdPs support attribute transformations natively, so external scripts or middleware may be necessary.Configure Attribute Mappings in WorkOS:
Make sure the attribute mappings (like UPN or email) in WorkOS are aligned with your normalization process, ensuring consistent data storage and retrieval.Consistent Retrieval During Login:
Verify that the SSO login flow always processes normalized (lowercase) UPNs for password generation and verification, reducing mismatches and login failures.
Why Normalize UPNs to Lowercase?
Enforcing lowercase UPNs provides multiple benefits:
Consistency:
Guarantees that the same UPN always results in the same password or identifier, preventing case-sensitive discrepancies.Reliability:
Reduces user login errors caused by case mismatches between stored attributes and those used during login.Simplified Logic:
Streamlines password management and credential validation by removing case sensitivity concerns.
Best Practices for SSO Setup with WorkOS
Normalize Attributes at the IdP Level:
Apply transformations such as converting to lowercase directly within your IdP configuration or scripts.Configure Attribute Mappings Carefully:
Ensure that UPN or email attributes in WorkOS follow your normalization rules, to maintain consistency across systems.Test Thoroughly After Changes:
After implementing normalization, conduct comprehensive tests to confirm that user provisioning, password generation, and login processes work seamlessly as expected.Document Procedures:
Maintain clear documentation of attribute normalization rules and setup procedures to ensure ongoing consistency.
Conclusion
In systems like WorkOS integrated with SSO, proper handling of user attribute normalization—particularly the case of UPNs—is vital for seamless authentication. Enforcing lowercase UPNs during user provisioning, migration, and login processes can eliminate a range of issues, improving user experience and system reliability. Implementing consistent normalization practices is a best practice that supports secure and straightforward user management.