What is the function of the Assertion Consumer Service URL in a SAML implementation?

TheAssertion Consumer Service (ACS) URLplays a critical role in a SAML (Security Assertion Markup Language) implementation. Its primary function is to specify the endpoint where the Identity Provider (IdP) should send the SAML response after successfully authenticating a user. This URL is part of the Service Provider (SP) configuration and is used by the IdP to redirect the user back to the SP with the authentication assertion.

Option A: Incorrect. The ACS URL does not enable proxy or linked pages like login or error pages. These are separate configurations.

Option B: Incorrect. While the SAML response may contain information about the user's logged-in status, the ACS URL itself does not "assert" this status. Its role is purely to receive the SAML response.

Option C: Correct. The ACS URL is explicitly defined to instruct the IdP where to send the SAML response containing the authentication assertion.

Option D: Incorrect. The ACS URL is not related to entering credentials. It is a destination for receiving the SAML response.

References:

SAP Customer Data Cloud - SAML Integration

SAML Protocol Overview