The ICertPassage Remote Protocol exposes a Remote Procedure Call (RPC) (as specified in [MS-RPCE]) interface that allows a client to interact with a certification authority (CA) to request and receive X.509 certificates (as specified in [X509]) from the CA. The ICertPassage Remote Protocol only provides certificate enrollment functionality. The Windows Client Certificate Enrollment Protocol (as specified in [MS-WCCE]) provides a larger set of functionality, including reading CA data and configuration information. The certificate enrollment process and protocol overview are as specified in [MS-WCCE] section 1.3.
The ICertPassage interface defines one method: CertServerRequest (section 18.104.22.168.1).