When StoreFront must integrate with a third-party portal, the portal typically acts as the external system that captures user credentials, handles primary authentication, and then passes those credentials (usually via HTTP headers or basic authentication mechanisms) to StoreFront.
Citrix documentation notes that HTTP Basic authentication is the method suited for integrations where StoreFront must accept credentials from an external portal or non-Citrix authentication framework. This method allows StoreFront to validate credentials passed programmatically from the third-party system.
Why not the other options?
Unauthenticated: This provides anonymous access and does not support integration with authenticated external portals.
Domain pass-through: Requires a Windows-integrated authentication flow, not compatible with third-party portals.
Pass-through from NetScaler Gateway: This applies only when authentication is performed via Citrix Gateway, not an external custom portal.
Therefore, HTTP Basic is the appropriate authentication method for third-party portal integration.
Documentation References:
StoreFront Authentication Methods Overview
StoreFront Third-Party Integration Scenarios (Authentication Requirements)