SharePoint 2016 FBA onprem .NET WebSDK

[Casey2]

Looking for tips from anyone that’s configured SharePoint with the DUO WebSDK. We’ve configured SharePoint 2016 FBA with the DUO WebSDK and its works well except for one aspect regarding FBA authentication.

login page 1.) authenticate the username and password using FBA-LDAP.
login page 2.) load the duo web iframe

The method that authenticates the username and password on login page 1 is the SPClaimsUtility.AuthenticateFormsUser which persists a cookie to the site.

If the user fails the DUO authentication on login page 2, they still have an authenticated session to the site. We can force a signout and clear session cookies, but I was hoping for a cleaner approach. Please assist.

Thanks!

[Casey2]

We resolved this by validating credentials on the first login page with Membership.ValidateUser which validates against the user store without creating a persisted cookie. On the second page once the user has successfully passed DUO authentication we used the SPClaimsUtility.AuthenticateFormsUser. Hope this helps anyone out there! Have a good one.

[Amy2]

Thank you, Casey, for following up to share the answer with the community! Glad you found the solution you needed.