Certificate Management Messages over CMS
RFC 2797

Network Working Group                                            M. Myers
Request for Comments: 2797                                       VeriSign
Category: Standards Track                                          X. Liu
                                                                    Cisco
                                                                J. Schaad
                                                                Microsoft
                                                             J. Weinstein
                                                               April 2000

                Certificate Management Messages over CMS

Status of this Memo

   This document specifies an Internet standards track protocol for the
   Internet community, and requests discussion and suggestions for
   improvements.  Please refer to the current edition of the "Internet
   Official Protocol Standards" (STD 1) for the standardization state
   and status of this protocol.  Distribution of this memo is unlimited.

Copyright Notice

   Copyright (C) The Internet Society (2000).  All Rights Reserved.

Abstract

   This document defines a Certificate Management protocol using CMS
   (CMC).  This protocol addresses two immediate needs within the
   Internet PKI community:

   1. The need for an interface to public key certification products and
      services based on [CMS] and [PKCS10], and
   2. The need in [SMIMEV3] for a certificate enrollment protocol for
      DSA-signed certificates with Diffie-Hellman public keys.

   A small number of additional services are defined to supplement the
   core certificate request service.

   Throughout this specification the term CMS is used to refer to both
   [CMS] and [PKCS7].  For both signedData and envelopedData, CMS is a
   superset of the PKCS7. In general, the use of PKCS7 in this document
   is aligned to the Cryptographic Message Syntax [CMS] that provides a
   superset of the PKCS7 syntax. The term CMC refers to this
   specification.

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED",  "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in [RFC 2119].

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RFC 2797        Certificate Management Messages over CMS      April 2000

1.  Protocol Requirements

   -  The protocol is to be based as much as possible on the existing
      CMS, PKCS#10 and CRMF specifications.
   -  The protocol must support the current industry practice of a
      PKCS#10 request followed by a PKCS#7 response as a subset of the
      protocol.
   -  The protocol needs to easily support the multi-key enrollment
      protocols required by S/MIME and other groups.
   -  The protocol must supply a way of doing all operations in a
      single-round trip.  When this is not possible the number of round
      trips is to be minimized.
   -  The protocol will be designed such that all key generation can
      occur on the client.
   -  The mandatory algorithms must superset the required algorithms for
      S/MIME.
   -  The protocol will contain POP methods. Optional provisions for
      multiple-round trip POP will be made if necessary.
   -  The protocol will support deferred and pending responses to
      certificate request for cases where external procedures are
      required to issue a certificate.
   -  The protocol needs to support arbitrary chains of local
      registration authorities as intermediaries between certificate
      requesters and issuers.

2.  Protocol Overview

   An enrollment transaction in this specification is generally composed
   of a single round trip of messages.  In the simplest case an
   enrollment request is sent from the client to the server and an
   enrollment response is then returned from the server to the client.
   In some more complicated cases, such as delayed certificate issuance
   and polling for responses, more than one round trip is required.

   This specification supports two different request messages and two
   different response messages.

   Public key certification requests can be based on either the PKCS10
   or CRMF object.  The two different request messages are (a) the bare
   PKCS10 (in the event that no other services are needed), and (b) the
   PKCS10 or CRMF message wrapped in a CMS encapsulation as part of a
   PKIData object.

   Public key certification responses are based on the CMS signedData
   object.  The response may be either (a) a degenerate CMS signedData
   object (in the event no other services are needed), or (b) a
   ResponseBody object wrapped in a CMS signedData object.

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