Certificate Management Protocol

CMP (Certificate Management Protocol)
family: unknown
field of application : certificate management
newest version: cmp2021(3)
OID of the newest version: 1.3.6.1.5.5.7.0.16
TCP/UDP port: 80 (http), 443 (https), 829 (pkix-3-ca-ra)
CMP in the TCP/IP model:
application CMP CMP
HTTP HTTPS CoAP SMTP ...
transport TCP
Internet IP (IPv4, IPv6)
link Ethernet Token
Bus
Token
Ring
FDDI ...
proposed standard:

RFC 4210 (CMPv2, 2005)
RFC 9480 (CMPv3, 2023)

obsolete standard:

RFC 2510 (CMPv1, 1999)

The Certificate Management Protocol (CMP) is an Internet protocol standardized by the IETF used for obtaining X.509 digital certificates in a public key infrastructure (PKI).

CMP is a very feature-rich and flexible protocol, supporting many types of cryptography. CMP messages are self-contained, which, as opposed to EST, makes the protocol independent of the transport mechanism and provides end-to-end security. CMP messages are encoded in ASN.1, using the DER method.

CMP is described in RFC 4210. Enrollment request messages employ the Certificate Request Message Format (CRMF), described in RFC 4211. The only other protocol so far using CRMF is Certificate Management over CMS (CMC), described in RFC 5273.