3751346 - SAP CPQ Redirects to Error404.aspx After Successful SAML Authentication

• After successful SAML authentication, SAP CPQ redirects to an error page instead of the SAP CPQ home page.
• The message displayed on the page is: "Sorry, that page doesn't exist!"
• Application logs may also contain a warning: "A public action method 'SingleSignOn' was not found on controller 'SAP.CPQ.Federation.Web.Saml.Controllers.FederationIdentityProviderController'."

"Image/data in this KBA is from SAP internal systems, sample data, or demo systems. Any resemblance to real data is purely coincidental."

SAP CPQ

1. Configure SAML Single Sign-On between the Identity Provider (IdP) and SAP CPQ.
2. Initiate login from the external application to CPQ.
3. Complete SAML authentication successfully.
4. Observe that SAP CPQ redirects to Error404.aspx instead of the configured landing page.

• This issue occurs if the identity provider is sending the SAMLResponse using an HTTP GET (Redirect) request instead of an HTTP POST. 
• CPQ expects the SAMLResponse in the POST body as per SAML 2.0 and does not support GET for this endpoint.
  
  

1. Review the Identity Provider (IdP) configuration.
2. Ensure that the Identity Provider is configured to send the SAMLResponse using the HTTP POST binding.
3. No changes are required in SAP CPQ.
4. If necessary:

1. 1. Download the latest Metadata XML from SAP CPQ.
   2. Import the metadata into the Identity Provider.
   3. Verify that the Identity Provider uses the endpoints defined in the SAP CPQ metadata.

cpq, saml, sso, idp-initiated, http-post, http-redirect, get vs post, samlresponse, error page, error404, controller singlesignon not found, federation, login redirect, acs endpoint, binding configuration , KBA , CEC-SAL-CPQ , Sales Cloud CPQ , Problem