Simple Certificate Enrolment Protocol
RFC 8894

Document Type RFC - Informational (September 2020; No errata)
Was draft-gutmann-scep (individual)
Author Peter Gutmann 
Last updated 2020-09-10
Replaces draft-nourse-scep
Stream IETF
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Stream WG state Submitted to IESG for Publication
Document shepherd Carl Wallace
Shepherd write-up Show (last changed 2018-01-25)
IESG IESG state RFC 8894 (Informational)
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Responsible AD Alexey Melnikov
Send notices to Carl Wallace <>,
IANA IANA review state Version Changed - Review Needed
IANA action state RFC-Ed-Ack

Internet Engineering Task Force (IETF)                        P. Gutmann
Request for Comments: 8894                        University of Auckland
Category: Informational                                   September 2020
ISSN: 2070-1721

                 Simple Certificate Enrolment Protocol


   This document specifies the Simple Certificate Enrolment Protocol
   (SCEP), a PKI protocol that leverages existing technology by using
   Cryptographic Message Syntax (CMS, formerly known as PKCS #7) and
   PKCS #10 over HTTP.  SCEP is the evolution of the enrolment protocol
   sponsored by Cisco Systems, which enjoys wide support in both client
   and server implementations, as well as being relied upon by numerous
   other industry standards that work with certificates.

Status of This Memo

   This document is not an Internet Standards Track specification; it is
   published for informational purposes.

   This document is a product of the Internet Engineering Task Force
   (IETF).  It represents the consensus of the IETF community.  It has
   received public review and has been approved for publication by the
   Internet Engineering Steering Group (IESG).  Not all documents
   approved by the IESG are candidates for any level of Internet
   Standard; see Section 2 of RFC 7841.

   Information about the current status of this document, any errata,
   and how to provide feedback on it may be obtained at

Copyright Notice

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   than English.

Table of Contents

   1.  Introduction
     1.1.  Conventions Used in This Document
   2.  SCEP Overview
     2.1.  SCEP Entities
       2.1.1.  Client
       2.1.2.  Certificate Authority
     2.2.  CA Certificate Distribution
     2.3.  Client Authentication
     2.4.  Enrolment Authorisation
     2.5.  Certificate Enrolment/Renewal
       2.5.1.  Client State Transitions
     2.6.  Certificate Access
     2.7.  CRL Access
     2.8.  Certificate Revocation
     2.9.  Mandatory-to-Implement Functionality
   3.  SCEP Secure Message Objects
     3.1.  SCEP Message Object Processing
     3.2.  SCEP pkiMessage
       3.2.1.  Signed Transaction Attributes  transactionID  messageType  pkiStatus  failInfo and failInfoText  senderNonce and recipientNonce
       3.2.2.  SCEP pkcsPKIEnvelope
     3.3.  SCEP pkiMessage types
       3.3.1.  PKCSReq/RenewalReq
       3.3.2.  CertRep  CertRep SUCCESS  CertRep FAILURE  CertRep PENDING
       3.3.3.  CertPoll (GetCertInitial)
       3.3.4.  GetCert and GetCRL
     3.4.  Degenerate certificates-only CMS SignedData
     3.5.  CA Capabilities
       3.5.1.  GetCACaps HTTP Message Format
       3.5.2.  CA Capabilities Response Format
   4.  SCEP Transactions
     4.1.  HTTP POST and GET Message Formats
     4.2.  Get CA Certificate
       4.2.1.  Get CA Certificate Response Message Format  CA Certificate Response Message Format  CA Certificate Chain Response Message Format
     4.3.  Certificate Enrolment/Renewal
       4.3.1.  Certificate Enrolment/Renewal Response Message
     4.4.  Poll for Client Initial Certificate
       4.4.1.  Polling Response Message Format
     4.5.  Certificate Access
       4.5.1.  Certificate Access Response Message Format
     4.6.  CRL Access
       4.6.1.  CRL Access Response Message Format
     4.7.  Get Next Certificate Authority Certificate
       4.7.1.  Get Next CA Response Message Format
   5.  SCEP Transaction Examples
     5.1.  Successful Transactions
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