Here are some useful AD CS related Windows Protocol Specifications:
- [MS-CERSOD]: Certificate Services Protocols Overview
- [MS-WCCE]: Windows Client Certificate Enrollment Protocol
- [MS-CSRA]: Certificate Services Remote Administration Protocol
- [MS-CRTD]: Certificate Templates Structure
- [MS-OCSP]: Online Certificate Status Protocol (OCSP) Extensions
- [MS-OCSPA]: Microsoft OCSP Administration Protocol
- [MS-XCEP]: X.509 Certificate Enrollment Policy Protocol
- [MS-WSTEP]: WS-Trust X.509v3 Token Enrollment Extensions
- [MS-DTYP]: Windows Data Types
- [MS-PKCA]: Public Key Cryptography for Initial Authentication (PKINIT) in Kerberos Protocol
- [MS-KILE]: Kerberos Protocol Extensions
- Whitepapers