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Certificate Management Protocol (CMP) Updates
RFC 9480

Document Type RFC - Proposed Standard (November 2023)
Authors Hendrik Brockhaus , David von Oheimb , John Gray
Last updated 2023-11-05
RFC stream Internet Engineering Task Force (IETF)
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IESG Responsible AD Roman Danyliw
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RFC 9480


Internet Engineering Task Force (IETF)                      H. Brockhaus
Request for Comments: 9480                                 D. von Oheimb
Updates: 4210, 5912, 6712                                        Siemens
Category: Standards Track                                        J. Gray
ISSN: 2070-1721                                                  Entrust
                                                           November 2023

             Certificate Management Protocol (CMP) Updates

Abstract

   This document contains a set of updates to the syntax of Certificate
   Management Protocol (CMP) version 2 and its HTTP transfer mechanism.
   This document updates RFCs 4210, 5912, and 6712.

   The aspects of CMP updated in this document are using EnvelopedData
   instead of EncryptedValue, clarifying the handling of p10cr messages,
   improving the crypto agility, as well as adding new general message
   types, extended key usages to identify certificates for use with CMP,
   and well-known URI path segments.

   CMP version 3 is introduced to enable signaling support of
   EnvelopedData instead of EncryptedValue and signal the use of an
   explicit hash AlgorithmIdentifier in certConf messages, as far as
   needed.

Status of This Memo

   This is an Internet Standards Track document.

   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).  Further information on
   Internet Standards is available in 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
   https://www.rfc-editor.org/info/rfc9480.

Copyright Notice

   Copyright (c) 2023 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (https://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Revised BSD License text as described in Section 4.e of the
   Trust Legal Provisions and are provided without warranty as described
   in the Revised BSD License.

Table of Contents

   1.  Introduction
     1.1.  Convention and Terminology
   2.  Updates to RFC 4210 - Certificate Management Protocol (CMP)
     2.1.  New Section 1.1 - Changes Since RFC 4210
     2.2.  New Section 4.5 - Extended Key Usage
     2.3.  Update Section 5.1.1 - PKI Message Header
     2.4.  New Section 5.1.1.3 - CertProfile
     2.5.  Update Section 5.1.3.1 - Shared Secret Information
     2.6.  Replace Section 5.1.3.4 - Multiple Protection
     2.7.  Replace Section 5.2.2 - Encrypted Values
     2.8.  New Section 5.2.9 - GeneralizedTime
     2.9.  Update Section 5.3.4 - Certification Response
     2.10. Update Section 5.3.18 - Certificate Confirmation Content
     2.11. Update Section 5.3.19.2 - Signing Key Pair Types
     2.12. Update Section 5.3.19.3 - Encryption/Key Agreement Key Pair
            Types
     2.13. Replace Section 5.3.19.9 - Revocation Passphrase
     2.14. New Section 5.3.19.14 - CA Certificates
     2.15. New Section 5.3.19.15 - Root CA Certificate Update
     2.16. New Section 5.3.19.16 - Certificate Request Template
     2.17. New Section 5.3.19.17 - CRL Update Retrieval
     2.18. Update Section 5.3.21 - Error Message Content
     2.19. Replace Section 5.3.22 - Polling Request and Response
     2.20. Update Section 7 - Version Negotiation
     2.21. Update Section 7.1.1 - Clients Talking to RFC 2510 Servers
     2.22. Add Section 8.4 - Private Keys for Certificate Signing and
            CMP Message Protection
     2.23. Add Section 8.5 - Entropy of Random Numbers, Key Pairs, and
            Shared Secret Information
     2.24. Add Section 8.6 - Trust Anchor Provisioning Using CMP
            Messages
     2.25. Add Section 8.7 - Authorizing Requests for Certificates
            with Specific EKUs
     2.26. Update Appendix B - The Use of Revocation Passphrase
     2.27. Update Appendix C - Request Message Behavioral
            Clarifications
     2.28. Update Appendix D.1. - General Rules for Interpretation of
            These Profiles
     2.29. Update Appendix D.2. - Algorithm Use Profile
     2.30. Update Appendix D.4. - Initial Registration/Certification
            (Basic Authenticated Scheme)
   3.  Updates to RFC 6712 - HTTP Transfer for the Certificate
           Management Protocol (CMP)
     3.1.  Update Section 1 - Introduction
     3.2.  New Section 1.1 - Changes Since RFC 6712
     3.3.  Replace Section 3.6 - HTTP Request-URI
   4.  IANA Considerations
     4.1.  Updates to the ASN.1 Modules in RFCs 4210 and 5912
     4.2.  Updates to the IANA Considerations of RFC 4210
       4.2.1.  SMI Security for PKIX Extended Key Purpose Registry
       4.2.2.  SMI Security for PKIX CMP Information Types
       4.2.3.  SMI Security for PKIX CRMF Registration Controls
     4.3.  Updates to the IANA Considerations of RFC 6712
       4.3.1.  Well-Known URIs
       4.3.2.  Certificate Management Protocol (CMP) Registry
   5.  Security Considerations
   6.  References
     6.1.  Normative References
     6.2.  Informative References
   Appendix A.  ASN.1 Modules
     A.1.  Update to RFC 4210 - 1988 ASN.1 Module
     A.2.  Update to RFC 5912 - 2002 ASN.1 Module
   Acknowledgements
   Authors' Addresses

1.  Introduction

   While using CMP [RFC4210] in industrial and Internet of Things
   environments and developing the Lightweight CMP Profile [RFC9483],
   some limitations were identified in the original CMP specification.
   This document updates [RFC4210] and [RFC6712] to overcome these
   limitations.

   Among other updates, this document improves the crypto agility of
   CMP, which allows more flexibility for future advances in
   cryptography.

   This document also introduces new extended key usages to identify CMP
   endpoints on registration and certification authorities.

   The main content of [RFC4210] and [RFC6712] remains unchanged.  This
   document lists all sections that are updated, replaced, or added to
   the current text of the respective RFCs.

   The authors acknowledge that the style of the document is hard to
   read because the original RFCs must be read along with this document
   to get the complete content.  The working group decided to use this
   approach in order to keep the changes to [RFC4210] and [RFC6712] to
   the required minimum.  This was meant to speed up the editorial
   process and to minimize the effort spent on reviewing the full text
   of the original documents.

   However, [PKIX-CMP] and [HTTP-CMP] are intended to obsolete RFCs 4210
   and 6712, respectively; these documents also include the changes
   listed in this document.

1.1.  Convention and Terminology

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL" in this document are to be interpreted as described in
   BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

   Technical terminology is used in conformance with [RFC4210],
   [RFC4211], and [RFC5280].  The following key words are used:

   CA:    Certification authority, which issues certificates.

   RA:    Registration authority, an optional system component to which
          a CA delegates certificate management functions, such as
          authorization checks.

   KGA:   Key generation authority, which generates key pairs on behalf
          of an EE.  The KGA could be colocated with an RA or a CA.

   EE:    End entity, a user, device, or service that holds a PKI
          certificate.  An identifier for the EE is given as its subject
          of the certificate.

2.  Updates to RFC 4210 - Certificate Management Protocol (CMP)

2.1.  New Section 1.1 - Changes Since RFC 4210

   The following subsection describes feature updates to [RFC4210].
   They are always related to the base specification.  Hence, references
   to the original sections in [RFC4210] are used whenever possible.

   Insert this section after the current Section 1 of [RFC4210]:

   1.1.  Changes Since RFC 4210

   The following updates are made in this document:

   *  Adding new extended key usages for various CMP server types, e.g.,
      registration authority and certification authority, to express the
      authorization of the entity identified in the certificate
      containing the respective extended key usage extension that acts
      as the indicated PKI management entity.

   *  Extending the description of multiple protection to cover
      additional use cases, e.g., batch processing of messages.

   *  Offering EnvelopedData as the preferred choice next to
      EncryptedValue to better support crypto agility in CMP.  Note
      that, according to [RFC4211], Section 2.1, point 9, the use of the
      EncryptedValue structure has been deprecated in favor of the
      EnvelopedData structure.  [RFC4211] offers the EncryptedKey
      structure a choice of EncryptedValue and EnvelopedData for
      migration to EnvelopedData.  For reasons of completeness and
      consistency, the type EncryptedValue has been exchanged in all
      occurrences in [RFC4210].  This includes the protection of
      centrally generated private keys, encryption of certificates, and
      protection of revocation passphrases.  To properly differentiate
      the support of EnvelopedData instead of EncryptedValue, CMP
      version 3 is introduced in case a transaction is supposed to use
      EnvelopedData.

   *  Offering an optional hashAlg field in CertStatus that supports
      confirmation of certificates signed with signature algorithms,
      e.g., preparing for upcoming post quantum algorithms, not directly
      indicating a specific hash algorithm to use to compute the
      certHash.

   *  Adding new general message types to request CA certificates, a
      root CA update, a certificate request template, or a Certificate
      Revocation List (CRL) update.

   *  Extending the usage of polling to p10cr, certConf, rr, genm, and
      error messages.

   *  Deleting the mandatory algorithm profile in Appendix D.2 of
      [RFC4210] and referring to Section 7 of CMP Algorithms [RFC9481].

2.2.  New Section 4.5 - Extended Key Usage

   The following subsection introduces a new extended key usage for CMP
   servers authorized to centrally generate key pairs on behalf of end
   entities.

   Insert this section after Section 4.4.3 of [RFC4210]:

   4.5.  Extended Key Usage

   The extended key usage (EKU) extension indicates the purposes for
   which the certified key pair may be used.  Therefore, it restricts
   the use of a certificate to specific applications.

   A CA may want to delegate parts of its duties to other PKI management
   entities.  This section provides a mechanism to both prove this
   delegation and enable an automated means for checking the
   authorization of this delegation.  Such delegation may also be
   expressed by other means, e.g., explicit configuration.

   To offer automatic validation for the delegation of a role by a CA to
   another entity, the certificates used for CMP message protection or
   signed data for central key generation MUST be issued by the
   delegating CA and MUST contain the respective EKUs.  This proves the
   authorization of this entity by delegating CA to act in the given
   role, as described below.

   The OIDs to be used for these EKUs are:

      id-kp-cmcCA OBJECT IDENTIFIER ::= {
         iso(1) identified-organization(3) dod(6) internet(1)
         security(5) mechanisms(5) pkix(7) kp(3) 27 }

      id-kp-cmcRA OBJECT IDENTIFIER ::= {
         iso(1) identified-organization(3) dod(6) internet(1)
         security(5) mechanisms(5) pkix(7) kp(3) 28 }

      id-kp-cmKGA OBJECT IDENTIFIER ::= {
         iso(1) identified-organization(3) dod(6) internet(1)
         security(5) mechanisms(5) pkix(7) kp(3) 32 }

   Note: Section 2.10 of [RFC6402] specifies OIDs for a Certificate
   Management over CMS (CMC) CA and a CMC RA.  As the functionality of a
   CA and RA is not specific to any certificate management protocol
   (such as CMC or CMP), these EKUs are reused by CMP.

   The meaning of the id-kp-cmKGA EKU is as follows:

   CMP KGA:  CMP key generation authorities are CAs or are identified by
             the id-kp-cmKGA extended key usage.  The CMP KGA knows the
             private key it generated on behalf of the end entity.  This
             is a very sensitive service and needs specific
             authorization, which by default is with the CA certificate
             itself.  The CA may delegate its authorization by placing
             the id-kp-cmKGA extended key usage in the certificate used
             to authenticate the origin of the generated private key.
             The authorization may also be determined through local
             configuration of the end entity.

2.3.  Update Section 5.1.1 - PKI Message Header

   Section 5.1.1 of [RFC4210] describes the PKI message header.  This
   document introduces the new version 3, indicating support of
   EnvelopedData as specified in Section 2.7 and hashAlg as specified in
   Section 2.10.

   Replace the ASN.1 syntax of PKIHeader and the subsequent description
   of pvno with the following text:

      PKIHeader ::= SEQUENCE {
         pvno                INTEGER     { cmp1999(1), cmp2000(2),
                                           cmp2021(3) },
         sender              GeneralName,
         recipient           GeneralName,
         messageTime     [0] GeneralizedTime         OPTIONAL,
         protectionAlg   [1] AlgorithmIdentifier{ALGORITHM, {...}}
                             OPTIONAL,
         senderKID       [2] KeyIdentifier           OPTIONAL,
         recipKID        [3] KeyIdentifier           OPTIONAL,
         transactionID   [4] OCTET STRING            OPTIONAL,
         senderNonce     [5] OCTET STRING            OPTIONAL,
         recipNonce      [6] OCTET STRING            OPTIONAL,
         freeText        [7] PKIFreeText             OPTIONAL,
         generalInfo     [8] SEQUENCE SIZE (1..MAX) OF
                             InfoTypeAndValue     OPTIONAL
      }

      PKIFreeText ::= SEQUENCE SIZE (1..MAX) OF UTF8String

   The usage of the protocol version number (pvno) is described in
   Section 7.

2.4.  New Section 5.1.1.3 - CertProfile

   Section 5.1.1 of [RFC4210] defines the PKIHeader and id-it OIDs to be
   used in the generalInfo field.  This section introduces id-it-
   certProfile.

   Insert this section after Section 5.1.1.2 of [RFC4210]:

   5.1.1.3.  CertProfile

   This is used by the EE to indicate specific certificate profiles,
   e.g., when requesting a new certificate or a certificate request
   template; see Section 5.3.19.16.

      id-it-certProfile  OBJECT IDENTIFIER ::= {id-it 21}
      CertProfileValue ::= SEQUENCE SIZE (1..MAX) OF UTF8String

   When used in an ir/cr/kur/genm, the value MUST NOT contain more
   elements than the number of CertReqMsg or InfoTypeAndValue elements
   and the certificate profile names refer to the elements in the given
   order.

   When used in a p10cr, the value MUST NOT contain multiple certificate
   profile names.

2.5.  Update Section 5.1.3.1 - Shared Secret Information

   Section 5.1.3.1 of [RFC4210] describes the protection of a PKIMessage
   based on message authentication code (MAC) using the algorithm id-
   PasswordBasedMac.

   Replace the first paragraph with the following text:

   In this case, the sender and recipient share secret information with
   sufficient entropy (established via out-of-band means or from a
   previous PKI management operation).  PKIProtection will contain a MAC
   value and the protectionAlg MAY be one of the options described in
   CMP Algorithms [RFC9481].  The PasswordBasedMac is specified as
   follows (see also [RFC4211] and [RFC9045]):

   Replace the last paragraph with the following text (Note: This fixes
   Errata ID 2616):

   Note: It is RECOMMENDED that the fields of PBMParameter remain
   constant throughout the messages of a single transaction (e.g.,
   ir/ip/certConf/pkiConf) to reduce the overhead associated with
   PasswordBasedMac computation.

2.6.  Replace Section 5.1.3.4 - Multiple Protection

   Section 5.1.3.4 of [RFC4210] describes the nested message.  This
   document also enables using nested messages for batch-delivery
   transport of PKI messages between PKI management entities and with
   mixed body types.

   Replace the text of the section with the following text:

   5.1.3.4.  Multiple Protection

   When receiving a protected PKI message, a PKI management entity, such
   as an RA, MAY forward that message along with adding its own
   protection (which is a MAC or a signature, depending on the
   information and certificates shared between the RA and the CA).
   Additionally, multiple PKI messages MAY be aggregated.  There are
   several use cases for such messages.

   *  The RA confirms having validated and authorized a message and
      forwards the original message unchanged.

   *  The RA modifies the message(s) in some way (e.g., adds or modifies
      particular field values or adds new extensions) before forwarding
      them; then, it MAY create its own desired PKIBody.  If the changes
      made by the RA to PKIMessage break the POP of a certificate
      request, the RA MUST set the popo field to RAVerified.  It MAY
      include the original PKIMessage from the EE in the generalInfo
      field of PKIHeader of a nested message (to accommodate, for
      example, cases in which the CA wishes to check POP or other
      information on the original EE message).  The infoType to be used
      in this situation is {id-it 15} (see Section 5.3.19 for the value
      of id-it), and the infoValue is PKIMessages (contents MUST be in
      the same order as the message in PKIBody).

   *  A PKI management entity collects several messages that are to be
      forwarded in the same direction and forwards them in a batch.
      Request messages can be transferred as batch upstream (towards the
      CA); response or announce messages can be transferred as batch
      downstream (towards an RA but not to the EE).  For instance, this
      can be used when bridging an off-line connection between two PKI
      management entities.

   These use cases are accomplished by nesting the messages within a new
   PKI message.  The structure used is as follows:

      NestedMessageContent ::= PKIMessages

2.7.  Replace Section 5.2.2 - Encrypted Values

   Section 5.2.2 of [RFC4210] describes the use of EncryptedValue to
   transport encrypted data.  This document extends the encryption of
   data to preferably use EnvelopedData.

   Replace the text of the section with the following text:

   5.2.2.  Encrypted Values

   Where encrypted data (in this specification, private keys,
   certificates, or revocation passphrase) is sent in PKI messages, the
   EncryptedKey data structure is used.

      EncryptedKey ::= CHOICE {
         encryptedValue        EncryptedValue, -- deprecated
         envelopedData     [0] EnvelopedData }

   See Certificate Request Message Format (CRMF) [RFC4211] for
   EncryptedKey and EncryptedValue syntax and Cryptographic Message
   Syntax (CMS) [RFC5652] for EnvelopedData syntax.  Using the
   EncryptedKey data structure offers the choice to either use
   EncryptedValue (for backward compatibility only) or EnvelopedData.
   The use of the EncryptedValue structure has been deprecated in favor
   of the EnvelopedData structure.  Therefore, it is RECOMMENDED to use
   EnvelopedData.

   Note: The EncryptedKey structure defined in CRMF [RFC4211] is reused
   here, which makes the update backward compatible.  Using the new
   syntax with the untagged default choice EncryptedValue is bits-on-
   the-wire compatible with the old syntax.

   To indicate support for EnvelopedData, the pvno cmp2021 has been
   introduced.  Details on the usage of the protocol version number
   (pvno) are described in Section 7.

   The EncryptedKey data structure is used in CMP to transport a private
   key, certificate, or revocation passphrase in encrypted form.

   EnvelopedData is used as follows:

   *  It contains only one RecipientInfo structure because the content
      is encrypted only for one recipient.

   *  It may contain a private key in the AsymmetricKeyPackage
      structure, as defined in [RFC5958], that is wrapped in a
      SignedData structure, as specified in Section 5 of CMS [RFC5652]
      and [RFC8933], and signed by the Key Generation Authority.

   *  It may contain a certificate or revocation passphrase directly in
      the encryptedContent field.

   The content of the EnvelopedData structure, as specified in Section 6
   of CMS [RFC5652], MUST be encrypted using a newly generated symmetric
   content-encryption key.  This content-encryption key MUST be securely
   provided to the recipient using one of three key management
   techniques.

   The choice of the key management technique to be used by the sender
   depends on the credential available at the recipient:

   *  recipient's certificate with an algorithm identifier and a public
      key that supports key transport and where any given key usage
      extension allows keyEncipherment: The content-encryption key will
      be protected using the key transport key management technique, as
      specified in Section 6.2.1 of CMS [RFC5652].

   *  recipient's certificate with an algorithm identifier and a public
      key that supports key agreement and where any given key usage
      extension allows keyAgreement: The content-encryption key will be
      protected using the key agreement key management technique, as
      specified in Section 6.2.2 of CMS [RFC5652].

   *  a password or shared secret: The content-encryption key will be
      protected using the password-based key management technique, as
      specified in Section 6.2.4 of CMS [RFC5652].

2.8.  New Section 5.2.9 - GeneralizedTime

   The following subsection points implementers to [RFC5280] regarding
   usage of GeneralizedTime.

   Insert this section after Section 5.2.8.4 of [RFC4210]:

   5.2.9 GeneralizedTime

   GeneralizedTime is a standard ASN.1 type and SHALL be used as
   specified in Section 4.1.2.5.2 of [RFC5280].

2.9.  Update Section 5.3.4 - Certification Response

   Section 5.3.4 of [RFC4210] describes the Certification Response.
   This document updates the syntax by using the parent structure
   EncryptedKey instead of EncryptedValue, as described in Section 2.7
   above.  Additionally, it clarifies the certReqId to be used in
   response to a p10cr message.

   Replace the ASN.1 syntax with the following text (Note: This also
   fixes Errata ID 3949 and 4078):

      CertRepMessage ::= SEQUENCE {
          caPubs          [1] SEQUENCE SIZE (1..MAX) OF CMPCertificate
                              OPTIONAL,
          response            SEQUENCE OF CertResponse
      }

      CertResponse ::= SEQUENCE {
          certReqId           INTEGER,
          status              PKIStatusInfo,
          certifiedKeyPair    CertifiedKeyPair    OPTIONAL,
          rspInfo             OCTET STRING        OPTIONAL
          -- analogous to the id-regInfo-utf8Pairs string defined
          -- for regInfo in CertReqMsg [RFC4211]
      }

      CertifiedKeyPair ::= SEQUENCE {
         certOrEncCert       CertOrEncCert,
         privateKey      [0] EncryptedKey        OPTIONAL,
         -- See [RFC4211] for comments on encoding.
         publicationInfo [1] PKIPublicationInfo  OPTIONAL
      }

      CertOrEncCert ::= CHOICE {
         certificate     [0] CMPCertificate,
         encryptedCert   [1] EncryptedKey
      }

   Add the following as a new paragraph right after the ASN.1 syntax:

   A p10cr message contains exactly one CertificationRequestInfo data
   structure, as specified in PKCS #10 [RFC2986], but no certReqId.
   Therefore, the certReqId in the corresponding Certification Response
   (cp) message MUST be set to -1.

   Add the following as new paragraphs to the end of the section:

   The use of EncryptedKey is described in Section 5.2.2.

   Note: To indicate support for EnvelopedData, the pvno cmp2021 has
   been introduced.  Details on the usage of different protocol version
   numbers (pvno) are described in Section 7.

2.10.  Update Section 5.3.18 - Certificate Confirmation Content

   This section introduces an optional hashAlg field to the CertStatus
   type used in certConf messages to explicitly specify the hash
   algorithm for those certificates where no hash algorithm is specified
   in the signatureAlgorithm field.

   Replace the ASN.1 Syntax of CertStatus with the following text:

      CertStatus ::= SEQUENCE {
         certHash    OCTET STRING,
         certReqId   INTEGER,
         statusInfo  PKIStatusInfo OPTIONAL,
         hashAlg [0] AlgorithmIdentifier{DIGEST-ALGORITHM, {...}}
                     OPTIONAL
      }

   The hashAlg field SHOULD be used only in exceptional cases where the
   signatureAlgorithm of the certificate to be confirmed does not
   specify a hash algorithm in the OID or in the parameters.  In such
   cases, e.g., for EdDSA, the hashAlg MUST be used to specify the hash
   algorithm to be used for calculating the certHash value.  Otherwise,
   the certHash value SHALL be computed using the same hash algorithm as
   used to create and verify the certificate signature.  If hashAlg is
   used, the CMP version indicated by the certConf message header must
   be cmp2021(3).

2.11.  Update Section 5.3.19.2 - Signing Key Pair Types

   The following section clarifies the usage of the Signing Key Pair
   Types on referencing elliptic curves.

   Insert this note at the end of Section 5.3.19.2 of [RFC4210]:

   Note: In case several elliptic curves are supported, several id-
   ecPublicKey elements as defined in [RFC5480] need to be given, one
   per named curve.

2.12.  Update Section 5.3.19.3 - Encryption/Key Agreement Key Pair Types

   The following section clarifies the use of the Encryption/Key
   Agreement Key Pair Types on referencing elliptic curves.

   Insert this note at the end of Section 5.3.19.3 of [RFC4210]:

   Note: In case several elliptic curves are supported, several id-
   ecPublicKey elements as defined in [RFC5480] need to be given, one
   per named curve.

2.13.  Replace Section 5.3.19.9 - Revocation Passphrase

   Section 5.3.19.9 of [RFC4210] describes the provisioning of a
   revocation passphrase for authenticating a later revocation request.
   This document updates the handling by using the parent structure
   EncryptedKey instead of EncryptedValue to transport this information,
   as described in Section 2.7 above.

   Replace the text of the section with the following text:

   5.3.19.9.  Revocation Passphrase

   This MAY be used by the EE to send a passphrase to a CA/RA for the
   purpose of authenticating a later revocation request (in the case
   that the appropriate signing private key is no longer available to
   authenticate the request).  See Appendix B for further details on the
   use of this mechanism.

      GenMsg:    {id-it 12}, EncryptedKey
      GenRep:    {id-it 12}, < absent >

   The use of EncryptedKey is described in Section 5.2.2.

2.14.  New Section 5.3.19.14 - CA Certificates

   The following subsection describes PKI general messages using id-it-
   caCerts.  The intended use is specified in Section 4.3 of the
   Lightweight CMP Profile [RFC9483].

   Insert this section after Section 5.3.19.13 of [RFC4210]:

   5.3.19.14.  CA Certificates

   This MAY be used by the client to get CA certificates.

      GenMsg:    {id-it 17}, < absent >
      GenRep:    {id-it 17}, SEQUENCE SIZE (1..MAX) OF
                             CMPCertificate | < absent >

2.15.  New Section 5.3.19.15 - Root CA Certificate Update

   The following subsection describes PKI general messages using id-it-
   rootCaCert and id-it-rootCaKeyUpdate.  The use is specified in
   Section 4.3 of the Lightweight CMP Profile [RFC9483].

   Insert this section after the new Section 5.3.19.14:

   5.3.19.15.  Root CA Certificate Update

   This MAY be used by the client to get an update of a root CA
   certificate, which is provided in the body of the request message.
   In contrast to the ckuann message, this approach follows the request/
   response model.

   The EE SHOULD reference its current trust anchor in a TrustAnchor
   structure in the request body, giving the root CA certificate if
   available; otherwise, the public key value of the trust anchor is
   given.

      GenMsg:    {id-it 20}, RootCaCertValue | < absent >
      GenRep:    {id-it 18}, RootCaKeyUpdateContent | < absent >

      RootCaCertValue ::= CMPCertificate

      RootCaKeyUpdateValue ::= RootCaKeyUpdateContent

      RootCaKeyUpdateContent ::= SEQUENCE {
         newWithNew       CMPCertificate,
         newWithOld   [0] CMPCertificate OPTIONAL,
         oldWithNew   [1] CMPCertificate OPTIONAL
         }

   Note: In contrast to CAKeyUpdAnnContent, this type offers omitting
   newWithOld and oldWithNew in the GenRep message, depending on the
   needs of the EE.

2.16.  New Section 5.3.19.16 - Certificate Request Template

   The following subsection introduces the PKI general message using id-
   it-certReqTemplate.  Details are specified in Section 4.3 of the
   Lightweight CMP Profile [RFC9483].

   Insert this section after the new Section 5.3.19.15:

   5.3.19.16.  Certificate Request Template

   This MAY be used by the client to get a template containing
   requirements for certificate request attributes and extensions.  The
   controls id-regCtrl-algId and id-regCtrl-rsaKeyLen MAY contain
   details on the types of subject public keys the CA is willing to
   certify.

   The id-regCtrl-algId control MAY be used to identify a cryptographic
   algorithm (see Section 4.1.2.7 of [RFC5280]) other than
   rsaEncryption.  The algorithm field SHALL identify a cryptographic
   algorithm.  The contents of the optional parameters field will vary
   according to the algorithm identified.  For example, when the
   algorithm is set to id-ecPublicKey, the parameters identify the
   elliptic curve to be used; see [RFC5480].

   The id-regCtrl-rsaKeyLen control SHALL be used for algorithm
   rsaEncryption and SHALL contain the intended modulus bit length of
   the RSA key.

      GenMsg:    {id-it 19}, < absent >
      GenRep:    {id-it 19}, CertReqTemplateContent | < absent >

      CertReqTemplateValue  ::= CertReqTemplateContent

      CertReqTemplateContent ::= SEQUENCE {
        certTemplate           CertTemplate,
        keySpec                Controls OPTIONAL }

      Controls  ::= SEQUENCE SIZE (1..MAX) OF AttributeTypeAndValue

      id-regCtrl-algId OBJECT IDENTIFIER ::= { iso(1)
         identified-organization(3) dod(6) internet(1) security(5)
         mechanisms(5) pkix(7) pkip(5) regCtrl(1) 11 }

      AlgIdCtrl ::= AlgorithmIdentifier{ALGORITHM, {...}}

      id-regCtrl-rsaKeyLen OBJECT IDENTIFIER ::= { iso(1)
         identified-organization(3) dod(6) internet(1) security(5)
         mechanisms(5) pkix(7) pkip(5) regCtrl(1) 12 }

      RsaKeyLenCtrl ::= INTEGER (1..MAX)

   The CertReqTemplateValue contains the prefilled certTemplate to be
   used for a future certificate request.  The publicKey field in the
   certTemplate MUST NOT be used.  In case the PKI management entity
   wishes to specify supported public-key algorithms, the keySpec field
   MUST be used.  One AttributeTypeAndValue per supported algorithm or
   RSA key length MUST be used.

   Note: The controls ASN.1 type is defined in Section 6 of CRMF
   [RFC4211].

2.17.  New Section 5.3.19.17 - CRL Update Retrieval

   The following subsection introduces the PKI general message using id-
   it-crlStatusList and id-it-crls.  Details are specified in
   Section 4.3 of the Lightweight CMP Profile [RFC9483].  Insert this
   section after the new Section 5.3.19.16:

   5.3.19.17.  CRL Update Retrieval

   This MAY be used by the client to get new CRLs, specifying the source
   of the CRLs and the thisUpdate value of the latest CRL it already
   has, if available.  A CRL source is given either by a
   DistributionPointName or the GeneralNames of the issuing CA.  The
   DistributionPointName should be treated as an internal pointer to
   identify a CRL that the server already has and not as a way to ask
   the server to fetch CRLs from external locations.  The server shall
   only provide those CRLs that are more recent than the ones indicated
   by the client.

      GenMsg:    {id-it 22}, SEQUENCE SIZE (1..MAX) OF CRLStatus
      GenRep:    {id-it 23}, SEQUENCE SIZE (1..MAX) OF
                               CertificateList  |  < absent >

      CRLSource ::= CHOICE {
         dpn          [0] DistributionPointName,
         issuer       [1] GeneralNames }

      CRLStatus ::= SEQUENCE {
         source       CRLSource,
         thisUpdate   Time OPTIONAL }

2.18.  Update Section 5.3.21 - Error Message Content

   Section 5.3.21 of [RFC4210] describes the regular use of error
   messages.  This document adds a use by a PKI management entity to
   initiate delayed delivery in response to certConf, rr, and genm
   requests and to error messages.

   Replace the first sentence of the first paragraph with the following
   one:

   This data structure MAY be used by an EE, CA, or RA to convey error
   information and by a PKI management entity to initiate delayed
   delivery of responses.

   Replace the second paragraph with the following text:

   This message MAY be generated at any time during a PKI transaction.
   If the client sends this request, the server MUST respond with a
   PKIConfirm response or another ErrorMsg if any part of the header is
   not valid.  In case a PKI management entity sends an error message to
   the EE with the pKIStatusInfo field containing the status "waiting",
   the EE will initiate polling as described in Section 5.3.22.
   Otherwise, both sides MUST treat this message as the end of the
   transaction (if a transaction is in progress).

2.19.  Replace Section 5.3.22 - Polling Request and Response

   Section 5.3.22 of [RFC4210] describes when and how polling messages
   are used for ir, cr, and kur messages.  This document extends the
   polling mechanism for outstanding responses to any kind of request
   message.  This update also fixes the inconsistent use of the terms
   'pReq' vs. 'pollReq' and 'pRep' vs. 'pollRep'.

   Replace Section 5.3.22 of [RFC4210] with following text:

   This pair of messages is intended to handle scenarios in which the
   client needs to poll the server to determine the status of an
   outstanding response (i.e., when the "waiting" PKIStatus has been
   received).

      PollReqContent ::= SEQUENCE OF SEQUENCE {
         certReqId    INTEGER }

      PollRepContent ::= SEQUENCE OF SEQUENCE {
         certReqId    INTEGER,
         checkAfter   INTEGER,  -- time in seconds
         reason       PKIFreeText OPTIONAL }

   In response to an ir, cr, p10cr, or kur request message, polling is
   initiated with an ip, cp, or kup response message containing status
   "waiting".  For any type of request message, polling can be initiated
   with an error response messages with status "waiting".  The following
   clauses describe how polling messages are used.  It is assumed that
   multiple certConf messages can be sent during transactions.  There
   will be one sent in response to each ip, cp, or kup that contains a
   CertStatus for an issued certificate.

   1  In response to an ip, cp, or kup message, an EE will send a
      certConf for all issued certificates and expect a PKIconf for each
      certConf.  An EE will send a pollReq message in response to each
      CertResponse element of an ip, cp, or kup message with status
      "waiting" and in response to an error message with status
      "waiting".  Its certReqId MUST be either the index of a
      CertResponse data structure with status "waiting" or -1, referring
      to the complete response.

   2  In response to a pollReq, a CA/RA will return an ip, cp, or kup if
      one or more of the still pending requested certificates are ready
      or the final response to some other type of request is available;
      otherwise, it will return a pollRep.

   3  If the EE receives a pollRep, it will wait for at least the number
      of seconds given in the checkAfter field before sending another
      pollReq.

   4  If the EE receives an ip, cp, or kup, then it will be treated in
      the same way as the initial response; if it receives any other
      response, then this will be treated as the final response to the
      original request.

   The following client-side state machine describes polling for
   individual CertResponse elements.

                               START
                                 |
                                 v
                              Send ir
                                 | ip
                                 v
                            Check status
                            of returned <------------------------+
                               certs                             |
                                 |                               |
       +------------------------>|<------------------+           |
       |                         |                   |           |
       |        (issued)         v       (waiting)   |           |
     Add to <----------- Check CertResponse ------> Add to       |
    conf list           for each certificate      pending list   |
                                 /                               |
                                /                                |
                   (conf list) /     (empty conf list)           |
                              /                     ip           |
                             /                 +-----------------+
      (empty pending list)  /                  |    pollRep
        END <---- Send certConf        Send pollReq---------->Wait
                         |                 ^   ^               |
                         |                 |   |               |
                         +-----------------+   +---------------+
                            (pending list)

   In the following exchange, the end entity is enrolling for two
   certificates in one request.

    Step  End Entity                       PKI
    --------------------------------------------------------------------
    1   Format ir
    2                    -> ir      ->
    3                                    Handle ir
    4                                    Manual intervention is
                                         required for both certs
    5                    <- ip      <-
    6   Process ip
    7   Format pollReq
    8                    -> pollReq  ->
    9                                    Check status of cert requests
    10                                   Certificates not ready
    11                                   Format pollRep
    12                   <- pollRep  <-
    13  Wait
    14  Format pollReq
    15                   -> pollReq  ->
    16                                   Check status of cert requests
    17                                   One certificate is ready
    18                                   Format ip
    19                   <- ip       <-
    20  Handle ip
    21  Format certConf
    22                   -> certConf ->
    23                                   Handle certConf
    24                                   Format ack
    25                   <- pkiConf   <-
    26  Format pollReq
    27                   -> pollReq  ->
    28                                   Check status of certificate
    29                                   Certificate is ready
    30                                   Format ip
    31                   <- ip       <-
    31  Handle ip
    32  Format certConf
    33                   -> certConf ->
    34                                   Handle certConf
    35                                   Format ack
    36                   <- pkiConf  <-

   The following client-side state machine describes polling for a
   complete response message.

                                   Start
                                     |
                                     | Send request
                                     |
                +----------- Receive response ------------+
                |                                         |
                | ip/cp/kup/error with                    | other
                | status "waiting"                        | response
                |                                         |
                v                                         |
    +------> Polling                                      |
    |           |                                         |
    |           | Send pollReq                            |
    |           | Receive response                        |
    |           |                                         |
    |   pollRep | other response                          |
    +-----------+------------------->+<-------------------+
                                     |
                                     v
                               Handle response
                                     |
                                     v
                                    End

   In the following exchange, the end entity is sending a general
   message request, and the response is delayed by the server.

    Step  End Entity                       PKI
    --------------------------------------------------------------------
    1   Format genm
    2                  -> genm     ->
    3                                 Handle genm
    4                                 delay in response is necessary
    5                                 Format error message "waiting"
                                      with certReqId set to -1
    6                   <- error   <-
    7   Process error
    8   Format pollReq
    9                   -> pollReq ->
    10                                Check status of original request
                                      general message response not ready
    11                                Format pollRep
    12                  <- pollRep <-
    13  Wait
    14  Format pollReq
    15                  -> pollReq ->
    16                                Check status of original request
                                      general message response is ready
    17                                Format genp
    18                  <- genp    <-
    19  Handle genp

2.20.  Update Section 7 - Version Negotiation

   Section 7 of [RFC4210] describes the use of CMP versions.  This
   document describes the handling of the additional CMP version
   cmp2021, which is introduced to indicate support of EnvelopedData and
   hashAlg.

   Replace the text of the second paragraph with the following text:

   If a client knows the protocol version(s) supported by the server
   (e.g., from a previous PKIMessage exchange or via some out-of-band
   means), then it MUST send a PKIMessage with the highest version
   supported by both it and the server.  If a client does not know what
   version(s) the server supports, then it MUST send a PKIMessage using
   the highest version it supports with the following exception.
   Version cmp2021 SHOULD only be used if cmp2021 syntax is needed for
   the request being sent or for the expected response.

   Note: Using cmp2000 as the default pvno is done to avoid extra
   message exchanges for version negotiation and to foster compatibility
   with cmp2000 implementations.  Version cmp2021 syntax is only needed
   if a message exchange uses hashAlg (in CertStatus) or EnvelopedData.

2.21.  Update Section 7.1.1 - Clients Talking to RFC 2510 Servers

   Section 7.1.1 of [RFC4210] describes the behavior of a client sending
   a cmp2000 message talking to a cmp1999 server, as specified in
   [RFC2510].  This document extends the section to clients with any
   higher version than cmp1999.

   Replace the first sentence of Section 7.1.1 of [RFC4210] with the
   following text:

   If, after sending a message with a protocol version number higher
   than cmp1999, a client receives an ErrorMsgContent with a version of
   cmp1999, then it MUST abort the current transaction.

2.22.  Add Section 8.4 - Private Keys for Certificate Signing and CMP
       Message Protection

   The following subsection addresses the risk arising from reusing the
   CA private key for CMP message protection.

   Insert this section after Section 8.3 of [RFC4210] (Note: This fixes
   Errata ID 5731):

   8.4.  Private Keys for Certificate Signing and CMP Message Protection

   A CA should not reuse its certificate signing key for other purposes,
   such as protecting CMP responses and TLS connections.  This way,
   exposure to other parts of the system and the number of uses of this
   particularly critical key are reduced to a minimum.

2.23.  Add Section 8.5 - Entropy of Random Numbers, Key Pairs, and
       Shared Secret Information

   The following subsection addresses the risk arising from low entropy
   of random numbers, asymmetric keys, and shared secret information.

   Insert this section after the new Section 8.4:

   8.5.  Entropy of Random Numbers, Key Pairs, and Shared Secret
   Information

   Implementations must generate nonces and private keys from random
   input.  The use of inadequate pseudorandom number generators (PRNGs)
   to generate cryptographic keys can result in little or no security.
   An attacker may find it much easier to reproduce the PRNG environment
   that produced the keys and to search the resulting small set of
   possibilities than brute-force searching the whole key space.  As an
   example of predictable random numbers, see [CVE-2008-0166];
   consequences of low-entropy random numbers are discussed in Mining
   Your Ps and Qs [MiningPsQs].  The generation of quality random
   numbers is difficult.  ISO/IEC 20543:2019 [ISO.20543-2019], NIST SP
   800-90A Rev.1 [NIST_SP_800_90Ar1], BSI AIS 31 V2.0 [AIS31], and other
   specifications offer valuable guidance in this area.

   If shared secret information is generated by a cryptographically
   secure random number generator (CSRNG), it is safe to assume that the
   entropy of the shared secret information equals its bit length.  If
   no CSRNG is used, the entropy of shared secret information depends on
   the details of the generation process and cannot be measured securely
   after it has been generated.  If user-generated passwords are used as
   shared secret information, their entropy cannot be measured and are
   typically insufficient for protected delivery of centrally generated
   keys or trust anchors.

   If the entropy of shared secret information protecting the delivery
   of a centrally generated key pair is known, it should not be less
   than the security strength of that key pair; if the shared secret
   information is reused for different key pairs, the security of the
   shared secret information should exceed the security strength of each
   individual key pair.

   For the case of a PKI management operation that delivers a new trust
   anchor (e.g., a root CA certificate) using caPubs or genm that is (a)
   not concluded in a timely manner or (b) where the shared secret
   information is reused for several key management operations, the
   entropy of the shared secret information, if known, should not be
   less than the security strength of the trust anchor being managed by
   the operation.  The shared secret information should have an entropy
   that at least matches the security strength of the key material being
   managed by the operation.  Certain use cases may require shared
   secret information that may be of a low security strength, e.g., a
   human-generated password.  It is RECOMMENDED that such secret
   information be limited to a single PKI management operation.

2.24.  Add Section 8.6 - Trust Anchor Provisioning Using CMP Messages

   The following subsection addresses the risk arising from in-band
   provisioning of new trust anchors in a PKI management operation.

   Insert this section after the new Section 8.5:

   8.6.  Trust Anchor Provisioning Using CMP Messages

   A provider of trust anchors, which may be an RA involved in
   configuration management of its clients, MUST NOT include to-be-
   trusted CA certificates in a CMP message unless the specific
   deployment scenario can ensure that it is adequate that the receiving
   EE trusts these certificates, e.g., by loading them into its trust
   store.

   Whenever an EE receives in a CMP message a CA certificate to be used
   as a trust anchor (for example in the caPubs field of a certificate
   response or in a general response), it MUST properly authenticate the
   message sender with existing trust anchor information without
   requiring the new trust anchors included in the message.

   Additionally, the EE MUST verify that the sender is an authorized
   source of trust anchors.  This authorization is governed by local
   policy and typically indicated using shared secret information or
   with a signature-based message protection using a certificate issued
   by a PKI that is explicitly authorized for this purpose.

2.25.  Add Section 8.7 - Authorizing Requests for Certificates with
       Specific EKUs

   The following subsection addresses the security considerations to
   follow when authorizing requests for certificates containing specific
   EKUs.

   Insert this section after new Section 8.6:

   8.7.  Authorizing Requests for Certificates with Specific EKUs

   When a CA issues a certificate containing extended key usage
   extensions as defined in Section 4.5, this expresses delegation of an
   authorization that originally is only with the CA certificate itself.
   Such delegation is a very sensitive action in a PKI and therefore
   special care must be taken when approving such certificate requests
   to ensure that only legitimate entities receive a certificate
   containing such an EKU.

2.26.  Update Appendix B - The Use of Revocation Passphrase

   Appendix B of [RFC4210] describes the use of the revocation
   passphrase.  As this document updates [RFC4210] to utilize the parent
   structure EncryptedKey instead of EncryptedValue as described in
   Section 2.7 above, the description is updated accordingly.

   Replace the first bullet point of this section with the following
   text:

   *  The OID and value specified in Section 5.3.19.9 MAY be sent in a
      GenMsg message at any time or MAY be sent in the generalInfo field
      of the PKIHeader of any PKIMessage at any time.  (In particular,
      the EncryptedKey structure as described in Section 5.2.2 may be
      sent in the header of the certConf message that confirms
      acceptance of certificates requested in an initialization request
      or certificate request message.)  This conveys a revocation
      passphrase chosen by the entity to the relevant CA/RA.  When
      EnvelopedData is used, this is in the decrypted bytes of the
      encryptedContent field.  When EncryptedValue is used, this is in
      the decrypted bytes of the encValue field.  Furthermore, the
      transfer is accomplished with appropriate confidentiality
      characteristics.

   Replace the third bullet point of this section with the following
   text:

   *  Either the localKeyId attribute of EnvelopedData as specified in
      [RFC2985] or the valueHint field of EncryptedValue MAY contain a
      key identifier (chosen by the entity, along with the passphrase
      itself) to assist in later retrieval of the correct passphrase
      (e.g., when the revocation request is constructed by the entity
      and received by the CA/RA).

2.27.  Update Appendix C - Request Message Behavioral Clarifications

   Appendix C of [RFC4210] provides clarifications to the request
   message behavior.  As this document updates [RFC4210] to utilize the
   parent structure EncryptedKey instead of EncryptedValue as described
   in Section 2.7 above, the description is updated accordingly.

   Replace the comment within the ASN.1 syntax coming after the
   definition of POPOSigningKey with the following text (Note: This
   fixes Errata ID 2615):

   -- **********
   -- * For the purposes of this specification, the ASN.1 comment
   -- * given in [RFC4211] pertains not only to certTemplate but
   -- * also to the altCertTemplate control.
   -- **********
   -- * The signature (using "algorithmIdentifier") is on the
   -- * DER-encoded value of poposkInput (i.e., the "value" OCTETs
   -- * of the POPOSigningKeyInput DER).  NOTE: If CertReqMsg
   -- * certReq certTemplate (or the altCertTemplate control)
   -- * contains the subject and publicKey values, then poposkInput
   -- * MUST be omitted and the signature MUST be computed on the
   -- * DER-encoded value of CertReqMsg certReq (or the DER-
   -- * encoded value of AltCertTemplate).  If
   -- * certTemplate/altCertTemplate does not contain both the
   -- * subject and public key values (i.e., if it contains only
   -- * one of these or neither), then poposkInput MUST be present
   -- * and MUST be signed.
   -- **********

   Replace the ASN.1 syntax of POPOPrivKey with the following text:

   POPOPrivKey ::= CHOICE {
       thisMessage       [0] BIT STRING,   -- deprecated
       subsequentMessage [1] SubsequentMessage,
       dhMAC             [2] BIT STRING,   -- deprecated
       agreeMAC          [3] PKMACValue,
       encryptedKey      [4] EnvelopedData }
   -- **********
   -- * When using CMP V2, the encrypted value MUST be transferred in
   -- * the thisMessage field that is given as BIT STRING in [RFC4211],
   -- * but it requires EncryptedValue. Therefore, this document makes
   -- * the behavioral clarification for CMP V2 of specifying that the
   -- * contents of "thisMessage" MUST be encoded as an
   -- * EncryptedValue and then wrapped in a BIT STRING.
   -- * When using CMP V3, the encrypted value MUST be transferred
   -- * in the encryptedKey field, as specified in Section 5.2.2.
   -- **********

2.28.  Update Appendix D.1. - General Rules for Interpretation of These
       Profiles

   Appendix D.1 of [RFC4210] provides general rules for interpretation
   of the PKI management messages profiles specified in Appendices D and
   E of [RFC4210].  This document updates a sentence regarding the new
   protocol version cmp2021.

   Replace the last sentence of the first paragraph of the section with
   the following text:

   Mandatory fields are not mentioned if they have an obvious value
   (e.g., in this version of these profiles, pvno is always cmp2000).

2.29.  Update Appendix D.2. - Algorithm Use Profile

   Appendix D.2 of [RFC4210] provides a list of algorithms that
   implementations must support when claiming conformance with PKI
   management message profiles, as specified in Appendix D.2 of CMP
   [RFC4210].  This document redirects to the new algorithm profile, as
   specified in Section 7.1 of CMP Algorithms [RFC9481].

   Replace the text of the section with the following text:

   D.2.  Algorithm Use Profile

   For specifications of algorithm identifiers and respective
   conventions for conforming implementations, please refer to
   Section 7.1 of CMP Algorithms [RFC9481].

2.30.  Update Appendix D.4. - Initial Registration/Certification (Basic
       Authenticated Scheme)

   Appendix D.4 of [RFC4210] provides the initial registration/
   certification scheme.  This scheme shall continue using
   EncryptedValue for backward compatibility reasons.

   Replace the line specifying protectionAlg of the Initialization
   Response message with the following text (Note: This fixes Errata ID
   5201):

   protectionAlg        MSG_MAC_ALG

   Replace the comment after the privateKey field of
   crc[1].certifiedKeyPair in the syntax of the Initialization Response
   message with the following text:

      -- see Appendix C (Request Message Behavioral Clarifications)
      -- for backward compatibility reasons, use EncryptedValue

3.  Updates to RFC 6712 - HTTP Transfer for the Certificate Management
    Protocol (CMP)

3.1.  Update Section 1 - Introduction

   To indicate and explain why delayed delivery of all kinds of
   PKIMessages may be handled at transfer level and/or at CMP level, the
   introduction of [RFC6712] is updated.

   Replace the third paragraph of this section with the following text:

   In addition to reliable transport, CMP requires connection and error
   handling from the transfer protocol, which is all covered by HTTP.
   Additionally, delayed delivery of CMP response messages may be
   handled at transfer level, regardless of the message contents.  Since
   this document extends the polling mechanism specified in the second
   version of CMP [RFC4210] to cover all types of PKI management
   transactions, delays detected at application level may also be
   handled within CMP, using pollReq and pollRep messages.

3.2.  New Section 1.1 - Changes Since RFC 6712

   The following subsection describes feature updates to [RFC6712].
   They are related to the base specification.  Hence, references to the
   original sections in [RFC6712] are used whenever possible.

   Insert this section after the current Section 1 of [RFC6712]:

   1.1 Changes Since RFC 6712

   The following updates are made in this document:

   *  Introduce the HTTP path '/.well-known/cmp'.

   *  Extend the URI structure.

3.3.  Replace Section 3.6 - HTTP Request-URI

   Section 3.6 of [RFC6712] specifies the used HTTP URIs.  This document
   introduces the HTTP path '/.well-known/cmp' and extends the URIs.

   Replace the text of the section with the following text:

   3.6.  HTTP Request-URI

   Each CMP server on a PKI management entity supporting HTTP or HTTPS
   transfer MUST support the use of the path prefix '/.well-known/' as
   defined in [RFC8615] and the registered name 'cmp' to ease
   interworking in a multi-vendor environment.

   The CMP client needs to be configured with sufficient information to
   form the CMP server URI.  This is at least the authority portion of
   the URI, e.g., 'www.example.com:80', or the full operation path
   segment of the PKI management entity.  Additionally, OPTIONAL path
   segments MAY be added after the registered application name as part
   of the full operation path to provide further distinction.  The path
   segment 'p' followed by an arbitraryLabel <name> could, for example,
   support the differentiation of specific CAs or certificate profiles.
   Further path segments, e.g., as specified in the Lightweight CMP
   Profile [RFC9483], could indicate PKI management operations using an
   operationLabel <operation>.  A valid, full CMP URI can look like
   this:

      http://www.example.com/.well-known/cmp
      http://www.example.com/.well-known/cmp/<operation>
      http://www.example.com/.well-known/cmp/p/<name>
      http://www.example.com/.well-known/cmp/p/<name>/<operation>

4.  IANA Considerations

4.1.  Updates to the ASN.1 Modules in RFCs 4210 and 5912

   This document updates the ASN.1 modules of Appendix F of [RFC4210]
   and Section 9 of [RFC5912] as shown in Appendixes A.1 and A.2 of this
   document, respectively.  The OIDs 99 (id-mod-cmp2021-88) and 100 (id-
   mod-cmp2021-02) have been registered in the "SMI Security for PKIX
   Module Identifier" registry to identify the updated ASN.1 modules.

4.2.  Updates to the IANA Considerations of RFC 4210

   This document updates the IANA Consideration sections of [RFC4210] by
   adding this content.

4.2.1.  SMI Security for PKIX Extended Key Purpose Registry

   IANA has registered the following new entry in the "SMI Security for
   PKIX Extended Key Purpose" registry (see
   <https://www.iana.org/assignments/smi-numbers>, as defined in
   [RFC7299]:

   +=========+=============+============+
   | Decimal | Description | References |
   +=========+=============+============+
   | 32      | id-kp-cmKGA | RFC 9480   |
   +---------+-------------+------------+

        Table 1: Addition to the SMI
       Security for PKIX Extended Key
                  Purpose

4.2.2.  SMI Security for PKIX CMP Information Types

   IANA has registered the following new entries in the "SMI Security
   for PKIX CMP Information Types" registry (see
   <https://www.iana.org/assignments/smi-numbers>), as defined in
   [RFC7299]:

   +=========+=======================+============+
   | Decimal | Description           | References |
   +=========+=======================+============+
   | 17      | id-it-caCerts         | RFC 9480   |
   +---------+-----------------------+------------+
   | 18      | id-it-rootCaKeyUpdate | RFC 9480   |
   +---------+-----------------------+------------+
   | 19      | id-it-certReqTemplate | RFC 9480   |
   +---------+-----------------------+------------+
   | 20      | id-it-rootCaCert      | RFC 9480   |
   +---------+-----------------------+------------+
   | 21      | id-it-certProfile     | RFC 9480   |
   +---------+-----------------------+------------+
   | 22      | id-it-crlStatusList   | RFC 9480   |
   +---------+-----------------------+------------+
   | 23      | id-it-crls            | RFC 9480   |
   +---------+-----------------------+------------+

          Table 2: Additions to the PKIX CMP
              Information Types Registry

4.2.3.  SMI Security for PKIX CRMF Registration Controls

   IANA has registered the following new entries in the "SMI Security
   for PKIX CRMF Registration Controls" registry (see
   <https://www.iana.org/assignments/smi-numbers>), as defined in
   [RFC7299]:

   +=========+======================+============+
   | Decimal | Description          | References |
   +=========+======================+============+
   | 11      | id-regCtrl-algId     | RFC 9480   |
   +---------+----------------------+------------+
   | 12      | id-regCtrl-rsaKeyLen | RFC 9480   |
   +---------+----------------------+------------+

          Table 3: Addition to the PKIX CRMF
            Registration Controls Registry

4.3.  Updates to the IANA Considerations of RFC 6712

   This document contains an update to the IANA Considerations sections
   of [RFC6712] by adding this content.

4.3.1.  Well-Known URIs

   IANA has registered the following new entry in the "Well-Known URIs"
   registry (see <https://www.iana.org/assignments/well-known-uris>), as
   defined in [RFC8615]:

   URI Suffix:  cmp
   Change Controller:  IETF
   Reference:  [RFC9480] [RFC9482]
   Status:  permanent
   Related Information:  CMP has a registry at
      <https://www.iana.org/assignments/cmp>

4.3.2.  Certificate Management Protocol (CMP) Registry

   This document defines a new protocol registry group entitled
   "Certificate Management Protocol (CMP)" (at
   <https://www.iana.org/assignments/cmp>) with a new "CMP Well-Known
   URI Path Segments" registry containing three columns: Path Segment,
   Description, and Reference.  New items can be added using the
   Specification Required [RFC8615] process.  The initial entry of this
   registry is:

   Path Segment:  p
   Description:  Indicates that the next path segment specifies, e.g., a
      CA or certificate profile name
   Reference:  [RFC9480] [RFC9482]

5.  Security Considerations

   The security considerations of [RFC4210] are extended in Section 2.22
   to Section 2.24.  No security considerations updates of [RFC6712]
   were required.

6.  References

6.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <https://www.rfc-editor.org/info/rfc2119>.

   [RFC2510]  Adams, C. and S. Farrell, "Internet X.509 Public Key
              Infrastructure Certificate Management Protocols",
              RFC 2510, DOI 10.17487/RFC2510, March 1999,
              <https://www.rfc-editor.org/info/rfc2510>.

   [RFC2985]  Nystrom, M. and B. Kaliski, "PKCS #9: Selected Object
              Classes and Attribute Types Version 2.0", RFC 2985,
              DOI 10.17487/RFC2985, November 2000,
              <https://www.rfc-editor.org/info/rfc2985>.

   [RFC2986]  Nystrom, M. and B. Kaliski, "PKCS #10: Certification
              Request Syntax Specification Version 1.7", RFC 2986,
              DOI 10.17487/RFC2986, November 2000,
              <https://www.rfc-editor.org/info/rfc2986>.

   [RFC3629]  Yergeau, F., "UTF-8, a transformation format of ISO
              10646", STD 63, RFC 3629, DOI 10.17487/RFC3629, November
              2003, <https://www.rfc-editor.org/info/rfc3629>.

   [RFC4210]  Adams, C., Farrell, S., Kause, T., and T. Mononen,
              "Internet X.509 Public Key Infrastructure Certificate
              Management Protocol (CMP)", RFC 4210,
              DOI 10.17487/RFC4210, September 2005,
              <https://www.rfc-editor.org/info/rfc4210>.

   [RFC4211]  Schaad, J., "Internet X.509 Public Key Infrastructure
              Certificate Request Message Format (CRMF)", RFC 4211,
              DOI 10.17487/RFC4211, September 2005,
              <https://www.rfc-editor.org/info/rfc4211>.

   [RFC5280]  Cooper, D., Santesson, S., Farrell, S., Boeyen, S.,
              Housley, R., and W. Polk, "Internet X.509 Public Key
              Infrastructure Certificate and Certificate Revocation List
              (CRL) Profile", RFC 5280, DOI 10.17487/RFC5280, May 2008,
              <https://www.rfc-editor.org/info/rfc5280>.

   [RFC5480]  Turner, S., Brown, D., Yiu, K., Housley, R., and T. Polk,
              "Elliptic Curve Cryptography Subject Public Key
              Information", RFC 5480, DOI 10.17487/RFC5480, March 2009,
              <https://www.rfc-editor.org/info/rfc5480>.

   [RFC5652]  Housley, R., "Cryptographic Message Syntax (CMS)", STD 70,
              RFC 5652, DOI 10.17487/RFC5652, September 2009,
              <https://www.rfc-editor.org/info/rfc5652>.

   [RFC5958]  Turner, S., "Asymmetric Key Packages", RFC 5958,
              DOI 10.17487/RFC5958, August 2010,
              <https://www.rfc-editor.org/info/rfc5958>.

   [RFC6402]  Schaad, J., "Certificate Management over CMS (CMC)
              Updates", RFC 6402, DOI 10.17487/RFC6402, November 2011,
              <https://www.rfc-editor.org/info/rfc6402>.

   [RFC6712]  Kause, T. and M. Peylo, "Internet X.509 Public Key
              Infrastructure -- HTTP Transfer for the Certificate
              Management Protocol (CMP)", RFC 6712,
              DOI 10.17487/RFC6712, September 2012,
              <https://www.rfc-editor.org/info/rfc6712>.

   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017, <https://www.rfc-editor.org/info/rfc8174>.

   [RFC8615]  Nottingham, M., "Well-Known Uniform Resource Identifiers
              (URIs)", RFC 8615, DOI 10.17487/RFC8615, May 2019,
              <https://www.rfc-editor.org/info/rfc8615>.

   [RFC8933]  Housley, R., "Update to the Cryptographic Message Syntax
              (CMS) for Algorithm Identifier Protection", RFC 8933,
              DOI 10.17487/RFC8933, October 2020,
              <https://www.rfc-editor.org/info/rfc8933>.

   [RFC9045]  Housley, R., "Algorithm Requirements Update to the
              Internet X.509 Public Key Infrastructure Certificate
              Request Message Format (CRMF)", RFC 9045,
              DOI 10.17487/RFC9045, June 2021,
              <https://www.rfc-editor.org/info/rfc9045>.

   [RFC9481]  Brockhaus, H., Aschauer, H., Ounsworth, M., and J. Gray,
              "Certificate Management Protocol (CMP) Algorithms",
              RFC 9481, DOI 10.17487/RFC9481, November 2023,
              <https://www.rfc-editor.org/info/rfc9481>.

   [RFC9482]  Sahni, M., Ed. and S. Tripathi, Ed., "Constrained
              Application Protocol (CoAP) Transfer for the Certificate
              Management Protocol", RFC 9482, DOI 10.17487/RFC9482,
              November 2023, <https://www.rfc-editor.org/info/rfc9482>.

6.2.  Informative References

   [AIS31]    Killmann, W. and W. Schindler, "A proposal for:
              Functionality classes for random number generators -
              Version 2.0", September 2011,
              <https://www.bsi.bund.de/SharedDocs/Downloads/DE/BSI/
              Zertifizierung/Interpretationen/AIS_31_Functionality_class
              es_for_random_number_generators_e.pdf>.

   [CVE-2008-0166]
              National Institute of Science and Technology (NIST),
              "National Vulnerability Database - CVE-2008-0166", May
              2008, <https://nvd.nist.gov/vuln/detail/CVE-2008-0166>.

   [HTTP-CMP] Brockhaus, H., von Oheimb, D., Ounsworth, M., and J. Gray,
              "Internet X.509 Public Key Infrastructure -- HTTP Transfer
              for the Certificate Management Protocol (CMP)", Work in
              Progress, Internet-Draft, draft-ietf-lamps-rfc6712bis-03,
              10 February 2023, <https://datatracker.ietf.org/doc/html/
              draft-ietf-lamps-rfc6712bis-03>.

   [ISO.20543-2019]
              International Organization for Standardization (ISO),
              "Information technology -- Security techniques -- Test and
              analysis methods for random bit generators within ISO/IEC
              19790 and ISO/IEC 15408", ISO/IEC 20543:2019, October
              2019.

   [MiningPsQs]
              Heninger, N., Durumeric, Z., Wustrow, E., and J. A.
              Halderman, "Mining Your Ps and Qs: Detection of Widespread
              Weak Keys in Network Devices", Security'12: Proceedings of
              the 21st USENIX conference on Security symposium, August
              2012, <https://www.usenix.org/conference/usenixsecurity12/
              technical-sessions/presentation/heninger>.

   [NIST_SP_800_90Ar1]
              Barker, E. B., Kelsey, J. M., and NIST, "Recommendation
              for Random Number Generation Using Deterministic Random
              Bit Generators", NIST Special Publications
              (General) 800-90Ar1, DOI 10.6028/NIST.SP.800-90Ar1, June
              2015,
              <https://nvlpubs.nist.gov/nistpubs/SpecialPublications/
              NIST.SP.800-90Ar1.pdf>.

   [PKIX-CMP] Brockhaus, H., von Oheimb, D., Ounsworth, M., and J. Gray,
              "Internet X.509 Public Key Infrastructure -- Certificate
              Management Protocol (CMP)", Work in Progress, Internet-
              Draft, draft-ietf-lamps-rfc4210bis-07, 19 June 2023,
              <https://datatracker.ietf.org/doc/html/draft-ietf-lamps-
              rfc4210bis-07>.

   [RFC2104]  Krawczyk, H., Bellare, M., and R. Canetti, "HMAC: Keyed-
              Hashing for Message Authentication", RFC 2104,
              DOI 10.17487/RFC2104, February 1997,
              <https://www.rfc-editor.org/info/rfc2104>.

   [RFC2202]  Cheng, P. and R. Glenn, "Test Cases for HMAC-MD5 and HMAC-
              SHA-1", RFC 2202, DOI 10.17487/RFC2202, September 1997,
              <https://www.rfc-editor.org/info/rfc2202>.

   [RFC5912]  Hoffman, P. and J. Schaad, "New ASN.1 Modules for the
              Public Key Infrastructure Using X.509 (PKIX)", RFC 5912,
              DOI 10.17487/RFC5912, June 2010,
              <https://www.rfc-editor.org/info/rfc5912>.

   [RFC7299]  Housley, R., "Object Identifier Registry for the PKIX
              Working Group", RFC 7299, DOI 10.17487/RFC7299, July 2014,
              <https://www.rfc-editor.org/info/rfc7299>.

   [RFC9483]  Brockhaus, H., von Oheimb, D., and S. Fries, "Lightweight
              Certificate Management Protocol (CMP) Profile", RFC 9483,
              DOI 10.17487/RFC9483, November 2023,
              <https://www.rfc-editor.org/info/rfc9483>.

Appendix A.  ASN.1 Modules

A.1.  Update to RFC 4210 - 1988 ASN.1 Module

   This section contains the updated ASN.1 module for [RFC4210].  This
   module replaces the module in Appendix F of that document.  Although
   a 2002 ASN.1 module is provided, this 1988 ASN.1 module remains the
   normative module, as per the policy of the PKIX Working Group.

   PKIXCMP {iso(1) identified-organization(3)
         dod(6) internet(1) security(5) mechanisms(5) pkix(7)
         id-mod(0) id-mod-cmp2021-88(99)}

   DEFINITIONS EXPLICIT TAGS ::=

   BEGIN

   -- EXPORTS ALL --

   IMPORTS

       Certificate, CertificateList, Extensions, Name, Time,
       AlgorithmIdentifier, id-kp
       --, UTF8String -- -- if required; otherwise, comment out
              FROM PKIX1Explicit88 {iso(1) identified-organization(3)
              dod(6) internet(1) security(5) mechanisms(5) pkix(7)
              id-mod(0) id-pkix1-explicit-88(18)}
       -- The import of Name is added to define CertificationRequest
       -- instead of importing it from PKCS #10 [RFC2986].

       DistributionPointName, GeneralNames, GeneralName, KeyIdentifier
              FROM PKIX1Implicit88 {iso(1) identified-organization(3)
              dod(6) internet(1) security(5) mechanisms(5) pkix(7)
              id-mod(0) id-pkix1-implicit-88(19)}

       CertTemplate, PKIPublicationInfo, EncryptedKey, CertId,
       CertReqMessages, Controls, AttributeTypeAndValue, id-regCtrl
              FROM PKIXCRMF-2005 {iso(1) identified-organization(3)
              dod(6) internet(1) security(5) mechanisms(5) pkix(7)
              id-mod(0) id-mod-crmf2005(36)}
       -- The import of EncryptedKey is added due to the updates made
       -- in CMP Updates [RFC9480]. EncryptedValue does not need to
       -- be imported anymore and is therefore removed here.

       -- Also, see the behavioral clarifications to CRMF codified in
       -- Appendix C of this specification.

       EnvelopedData, SignedData, Attribute
              FROM CryptographicMessageSyntax2004 { iso(1)
              member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
              smime(16) modules(0) cms-2004(24) }
       -- The import of EnvelopedData and SignedData is added due to
       -- the updates made in CMP Updates [RFC9480].
       -- The import of Attribute is added to define
       -- CertificationRequest instead of importing it from
       -- PKCS #10 [RFC2986].

       ;

   -- The rest of the module contains locally defined OIDs and
   -- constructs:

   CMPCertificate ::= CHOICE {
       x509v3PKCert        Certificate
   }
   -- This syntax, while bits-on-the-wire compatible with the
   -- standard X.509 definition of "Certificate", allows the
   -- possibility of future certificate types (such as X.509
   -- attribute certificates, card-verifiable
   -- certificates, or other kinds of certificates) within this
   -- Certificate Management Protocol, should a need ever arise to
   -- support such generality.  Those implementations that do not
   -- foresee a need to ever support other certificate types MAY, if
   -- they wish, comment out the above structure and "uncomment" the
   -- following one prior to compiling this ASN.1 module.  (Note that
   -- interoperability with implementations that don't do this will be
   -- unaffected by this change.)

   -- CMPCertificate ::= Certificate

   PKIMessage ::= SEQUENCE {
       header           PKIHeader,
       body             PKIBody,
       protection   [0] PKIProtection OPTIONAL,
       extraCerts   [1] SEQUENCE SIZE (1..MAX) OF CMPCertificate
                        OPTIONAL
   }

   PKIMessages ::= SEQUENCE SIZE (1..MAX) OF PKIMessage

   PKIHeader ::= SEQUENCE {
       pvno                INTEGER     { cmp1999(1), cmp2000(2),
                                         cmp2021(3) },
       sender              GeneralName,
       -- identifies the sender
       recipient           GeneralName,
       -- identifies the intended recipient
       messageTime     [0] GeneralizedTime         OPTIONAL,
       -- time of production of this message (used when the sender
       -- believes that the transport will be "suitable", i.e.,
       -- that the time will still be meaningful upon receipt)
       protectionAlg   [1] AlgorithmIdentifier     OPTIONAL,
       -- algorithm used for the calculation of protection bits
       senderKID       [2] KeyIdentifier           OPTIONAL,
       recipKID        [3] KeyIdentifier           OPTIONAL,
       -- to identify specific keys used for protection
       transactionID   [4] OCTET STRING            OPTIONAL,
       -- identifies the transaction, i.e., this will be the same in
       -- corresponding request, response, certConf, and PKIConf
       -- messages
       senderNonce     [5] OCTET STRING            OPTIONAL,
       recipNonce      [6] OCTET STRING            OPTIONAL,
       -- nonces used to provide replay protection, senderNonce
       -- is inserted by the creator of this message; recipNonce
       -- is a nonce previously inserted in a related message by
       -- the intended recipient of this message.
       freeText        [7] PKIFreeText             OPTIONAL,
       -- this may be used to indicate context-specific instructions
       -- (this field is intended for human consumption)
       generalInfo     [8] SEQUENCE SIZE (1..MAX) OF
                              InfoTypeAndValue     OPTIONAL
       -- this may be used to convey context-specific information
       -- (this field not primarily intended for human consumption)
   }

   PKIFreeText ::= SEQUENCE SIZE (1..MAX) OF UTF8String
       -- text encoded as a UTF-8 string [RFC3629]

   PKIBody ::= CHOICE {       -- message-specific body elements
       ir       [0]  CertReqMessages,        --Initialization Request
       ip       [1]  CertRepMessage,         --Initialization Response
       cr       [2]  CertReqMessages,        --Certification Request
       cp       [3]  CertRepMessage,         --Certification Response
       p10cr    [4]  CertificationRequest,   --imported from [RFC2986]
       popdecc  [5]  POPODecKeyChallContent, --pop Challenge
       popdecr  [6]  POPODecKeyRespContent,  --pop Response
       kur      [7]  CertReqMessages,        --Key Update Request
       kup      [8]  CertRepMessage,         --Key Update Response
       krr      [9]  CertReqMessages,        --Key Recovery Request
       krp      [10] KeyRecRepContent,       --Key Recovery Response
       rr       [11] RevReqContent,          --Revocation Request
       rp       [12] RevRepContent,          --Revocation Response
       ccr      [13] CertReqMessages,        --Cross-Cert. Request
       ccp      [14] CertRepMessage,         --Cross-Cert. Response
       ckuann   [15] CAKeyUpdAnnContent,     --CA Key Update Ann.
       cann     [16] CertAnnContent,         --Certificate Ann.
       rann     [17] RevAnnContent,          --Revocation Ann.
       crlann   [18] CRLAnnContent,          --CRL Announcement
       pkiconf  [19] PKIConfirmContent,      --Confirmation
       nested   [20] NestedMessageContent,   --Nested Message
       genm     [21] GenMsgContent,          --General Message
       genp     [22] GenRepContent,          --General Response
       error    [23] ErrorMsgContent,        --Error Message
       certConf [24] CertConfirmContent,     --Certificate Confirm
       pollReq  [25] PollReqContent,         --Polling Request
       pollRep  [26] PollRepContent          --Polling Response
   }

   PKIProtection ::= BIT STRING

   ProtectedPart ::= SEQUENCE {
       header    PKIHeader,
       body      PKIBody
   }

   id-PasswordBasedMac OBJECT IDENTIFIER ::= {1 2 840 113533 7 66 13}
   PBMParameter ::= SEQUENCE {
       salt                OCTET STRING,
       -- Note: Implementations MAY wish to limit acceptable sizes
       -- of this string to values appropriate for their environment
       -- in order to reduce the risk of denial-of-service attacks.
       owf                 AlgorithmIdentifier,
       -- AlgId for a One-Way Function (OWF)
       iterationCount      INTEGER,
       -- number of times the OWF is applied
       -- Note: Implementations MAY wish to limit acceptable sizes
       -- of this integer to values appropriate for their environment
       -- in order to reduce the risk of denial-of-service attacks.
       mac                 AlgorithmIdentifier
       -- the MAC AlgId (e.g., HMAC-SHA256, AES-GMAC [RFC9481],
   }   -- or HMAC [RFC2104, RFC2202])

   id-DHBasedMac OBJECT IDENTIFIER ::= {1 2 840 113533 7 66 30}
   DHBMParameter ::= SEQUENCE {
       owf                 AlgorithmIdentifier,
       -- AlgId for a One-Way Function
       mac                 AlgorithmIdentifier
       -- the MAC AlgId (e.g., HMAC-SHA256, AES-GMAC [RFC9481],
   }   -- or HMAC [RFC2104, RFC2202])

   NestedMessageContent ::= PKIMessages

   PKIStatus ::= INTEGER {
       accepted               (0),
       -- you got exactly what you asked for
       grantedWithMods        (1),
       -- you got something like what you asked for; the
       -- requester is responsible for ascertaining the differences
       rejection              (2),
       -- you don't get it, more information elsewhere in the message
       waiting                (3),
       -- the request body part has not yet been processed; expect to
       -- hear more later (note: proper handling of this status
       -- response MAY use the polling req/rep PKIMessages specified
       -- in Section 5.3.22 of [RFC4210]; alternatively, polling in the
       -- underlying transport layer MAY have some utility in this
       -- regard)
       revocationWarning      (4),
       -- this message contains a warning that a revocation is
       -- imminent
       revocationNotification (5),
       -- notification that a revocation has occurred
       keyUpdateWarning       (6)
       -- update already done for the oldCertId specified in
       -- CertReqMsg
   }

   PKIFailureInfo ::= BIT STRING {
   -- since we can fail in more than one way!
   -- More codes may be added in the future if/when required.
       badAlg              (0),
       -- unrecognized or unsupported algorithm identifier
       badMessageCheck     (1),
       -- integrity check failed (e.g., signature did not verify)
       badRequest          (2),
       -- transaction not permitted or supported
       badTime             (3),
       -- messageTime was not sufficiently close to the system time,
       -- as defined by local policy
       badCertId           (4),
       -- no certificate could be found matching the provided criteria
       badDataFormat       (5),
       -- the data submitted has the wrong format
       wrongAuthority      (6),
       -- the authority indicated in the request is different from the
       -- one creating the response token
       incorrectData       (7),
       -- the requester's data is incorrect (for notary services)
       missingTimeStamp    (8),
       -- when the timestamp is missing but should be there
       -- (by policy)
       badPOP              (9),
       -- the proof-of-possession failed
       certRevoked         (10),
       -- the certificate has already been revoked
       certConfirmed       (11),
       -- the certificate has already been confirmed
       wrongIntegrity      (12),
       -- not valid integrity, based on the password instead of the
       -- signature or vice versa
       badRecipientNonce   (13),
       -- not valid recipient nonce, either missing or wrong value
       timeNotAvailable    (14),
       -- the time source of the Time Stamping Authority (TSA) is
       -- not available
       unacceptedPolicy    (15),
       -- the requested TSA policy is not supported by the TSA
       unacceptedExtension (16),
       -- the requested extension is not supported by the TSA
       addInfoNotAvailable (17),
       -- the additional information requested could not be
       -- understood or is not available
       badSenderNonce      (18),
       -- not valid sender nonce, either missing or wrong size
       badCertTemplate     (19),
       -- not valid cert. template or missing mandatory information
       signerNotTrusted    (20),
       -- signer of the message unknown or not trusted
       transactionIdInUse  (21),
       -- the transaction identifier is already in use
       unsupportedVersion  (22),
       -- the version of the message is not supported
       notAuthorized       (23),
       -- the sender was not authorized to make the preceding
       -- request or perform the preceding action
       systemUnavail       (24),
       -- the request cannot be handled due to system unavailability
       systemFailure       (25),
       -- the request cannot be handled due to system failure
       duplicateCertReq    (26)
       -- the certificate cannot be issued because a duplicate
       -- certificate already exists
   }

   PKIStatusInfo ::= SEQUENCE {
       status        PKIStatus,
       statusString  PKIFreeText     OPTIONAL,
       failInfo      PKIFailureInfo  OPTIONAL
   }

   OOBCert ::= CMPCertificate

   OOBCertHash ::= SEQUENCE {
       hashAlg     [0] AlgorithmIdentifier     OPTIONAL,
       certId      [1] CertId                  OPTIONAL,
       hashVal         BIT STRING
       -- hashVal is calculated over the DER encoding of the
       -- self-signed certificate with the identifier certID.
   }

   POPODecKeyChallContent ::= SEQUENCE OF Challenge
   -- one Challenge per encryption key certification request (in the
   -- same order as these requests appear in CertReqMessages)

   Challenge ::= SEQUENCE {
       owf                 AlgorithmIdentifier  OPTIONAL,
       -- MUST be present in the first Challenge; MAY be omitted in
       -- any subsequent Challenge in POPODecKeyChallContent (if
       -- omitted, then the owf used in the immediately preceding
       -- Challenge is to be used)
       witness             OCTET STRING,
       -- the result of applying the One-Way Function (owf) to a
       -- randomly generated INTEGER, A (Note that a different
       -- INTEGER MUST be used for each Challenge.)
       challenge           OCTET STRING
       -- the encryption (under the public key for which the cert.
       -- request is being made) of Rand
   }

   -- Rand was added in CMP Updates [RFC9480]

   Rand ::= SEQUENCE {
   -- Rand is encrypted under the public key to form the challenge
   -- in POPODecKeyChallContent
      int                  INTEGER,
      -- the randomly generated INTEGER A (above)
      sender               GeneralName
      -- the sender's name (as included in PKIHeader)
   }

   POPODecKeyRespContent ::= SEQUENCE OF INTEGER
   -- One INTEGER per encryption key certification request (in the
   -- same order as these requests appear in CertReqMessages).  The
   -- retrieved INTEGER A (above) is returned to the sender of the
   -- corresponding Challenge.

   CertRepMessage ::= SEQUENCE {
       caPubs       [1] SEQUENCE SIZE (1..MAX) OF CMPCertificate
                        OPTIONAL,
       response         SEQUENCE OF CertResponse
   }

   CertificationRequest ::= SEQUENCE {
       certificationRequestInfo  SEQUENCE {
         version                   INTEGER,
         subject                   Name,
         subjectPublicKeyInfo      SEQUENCE {
           algorithm                 AlgorithmIdentifier,
           subjectPublicKey          BIT STRING },
         attributes                [0] IMPLICIT SET OF Attribute },
       signatureAlgorithm        AlgorithmIdentifier,
       signature                 BIT STRING
   }

   CertResponse ::= SEQUENCE {
       certReqId           INTEGER,
       -- to match this response with the corresponding request (a value
       -- of -1 is to be used if certReqId is not specified in the
       -- corresponding request, which can only be a p10cr)
       status              PKIStatusInfo,
       certifiedKeyPair    CertifiedKeyPair    OPTIONAL,
       rspInfo             OCTET STRING        OPTIONAL
       -- analogous to the id-regInfo-utf8Pairs string defined
       -- for regInfo in CertReqMsg [RFC4211]
   }

   CertifiedKeyPair ::= SEQUENCE {
       certOrEncCert       CertOrEncCert,
       privateKey      [0] EncryptedKey        OPTIONAL,
       -- See [RFC4211] for comments on encoding.
       -- Changed from Encrypted Value to EncryptedKey as a CHOICE of
       -- EncryptedValue and EnvelopedData due to the changes made in
       -- CMP Updates [RFC9480].
       -- Using the choice EncryptedValue is bit-compatible to the
       -- syntax without this change.
       publicationInfo [1] PKIPublicationInfo  OPTIONAL
   }

   CertOrEncCert ::= CHOICE {
       certificate     [0] CMPCertificate,
       encryptedCert   [1] EncryptedKey
       -- Changed from Encrypted Value to EncryptedKey as a CHOICE of
       -- EncryptedValue and EnvelopedData due to the changes made in
       -- CMP Updates [RFC9480].
       -- Using the choice EncryptedValue is bit-compatible to the
       -- syntax without this change.
   }

   KeyRecRepContent ::= SEQUENCE {
       status                  PKIStatusInfo,
       newSigCert          [0] CMPCertificate OPTIONAL,
       caCerts             [1] SEQUENCE SIZE (1..MAX) OF
                                           CMPCertificate OPTIONAL,
       keyPairHist         [2] SEQUENCE SIZE (1..MAX) OF
                                           CertifiedKeyPair OPTIONAL
   }

   RevReqContent ::= SEQUENCE OF RevDetails

   RevDetails ::= SEQUENCE {
       certDetails         CertTemplate,
       -- allows the requester to specify as much as they can about
       -- the cert. for which revocation is requested
       -- (e.g., for cases in which serialNumber is not available)
       crlEntryDetails     Extensions       OPTIONAL
       -- requested crlEntryExtensions
   }

   RevRepContent ::= SEQUENCE {
       status       SEQUENCE SIZE (1..MAX) OF PKIStatusInfo,
       -- in the same order as was sent in RevReqContent
       revCerts [0] SEQUENCE SIZE (1..MAX) OF CertId
                                           OPTIONAL,
       -- IDs for which revocation was requested
       -- (same order as status)
       crls     [1] SEQUENCE SIZE (1..MAX) OF CertificateList
                                           OPTIONAL
       -- the resulting CRLs (there may be more than one)
   }

   CAKeyUpdAnnContent ::= SEQUENCE {
       oldWithNew   CMPCertificate, -- old pub signed with new priv
       newWithOld   CMPCertificate, -- new pub signed with old priv
       newWithNew   CMPCertificate  -- new pub signed with new priv
   }

   CertAnnContent ::= CMPCertificate

   RevAnnContent ::= SEQUENCE {
       status              PKIStatus,
       certId              CertId,
       willBeRevokedAt     GeneralizedTime,
       badSinceDate        GeneralizedTime,
       crlDetails          Extensions  OPTIONAL
       -- extra CRL details (e.g., crl number, reason, location, etc.)
   }

   CRLAnnContent ::= SEQUENCE OF CertificateList

   CertConfirmContent ::= SEQUENCE OF CertStatus

   CertStatus ::= SEQUENCE {
      certHash    OCTET STRING,
      -- the hash of the certificate, using the same hash algorithm
      -- as is used to create and verify the certificate signature
      certReqId   INTEGER,
      -- to match this confirmation with the corresponding req/rep
      statusInfo  PKIStatusInfo OPTIONAL,
      hashAlg [0] AlgorithmIdentifier OPTIONAL
      -- the hash algorithm to use for calculating certHash
      -- SHOULD NOT be used in all cases where the AlgorithmIdentifier
      -- of the certificate signature specifies a hash algorithm
   }

   PKIConfirmContent ::= NULL

   -- CertReqTemplateContent, id-regCtrl-algId, id-regCtrl-algId, and
   -- id-regCtrl-rsaKeyLen were added in CMP Updates [RFC9480]

   CertReqTemplateContent ::= SEQUENCE {
      certTemplate           CertTemplate,
      -- prefilled certTemplate structure elements
      -- The SubjectPublicKeyInfo field in the certTemplate MUST NOT
      -- be used.
      keySpec                Controls OPTIONAL
      -- MAY be used to specify supported algorithms
      -- Controls  ::= SEQUENCE SIZE (1..MAX) OF AttributeTypeAndValue
      -- as specified in CRMF [RFC4211]
      }

   id-regCtrl-altCertTemplate OBJECT IDENTIFIER ::= { id-regCtrl 7 }
      AltCertTemplate ::= AttributeTypeAndValue
      -- specifies a template for a certificate other than an X.509v3
      -- public key certificate

   id-regCtrl-algId OBJECT IDENTIFIER ::= { id-regCtrl 11 }
      AlgIdCtrl ::= AlgorithmIdentifier
      -- SHALL be used to specify supported algorithms other than RSA

   id-regCtrl-rsaKeyLen OBJECT IDENTIFIER ::= { id-regCtrl 12 }
      RsaKeyLenCtrl ::= INTEGER (1..MAX)
      -- SHALL be used to specify supported RSA key lengths

   -- RootCaKeyUpdateContent, CRLSource, and CRLStatus were added in
   -- CMP Updates [RFC9480]

   RootCaKeyUpdateContent ::= SEQUENCE {
      newWithNew       CMPCertificate,
      -- new root CA certificate
      newWithOld   [0] CMPCertificate OPTIONAL,
      -- X.509 certificate containing the new public root CA key
      -- signed with the old private root CA key
      oldWithNew   [1] CMPCertificate OPTIONAL
      -- X.509 certificate containing the old public root CA key
      -- signed with the new private root CA key
      }

   CRLSource ::= CHOICE {
      dpn          [0] DistributionPointName,
      issuer       [1] GeneralNames }

   CRLStatus ::= SEQUENCE {
      source       CRLSource,
      thisUpdate   Time OPTIONAL }

   InfoTypeAndValue ::= SEQUENCE {
       infoType               OBJECT IDENTIFIER,
       infoValue              ANY DEFINED BY infoType  OPTIONAL
   }
   -- Example InfoTypeAndValue contents include, but are not limited
   -- to, the following (uncomment in this ASN.1 module and use as
   -- appropriate for a given environment):
   --
   --   id-it-caProtEncCert    OBJECT IDENTIFIER ::= {id-it 1}
   --      CAProtEncCertValue      ::= CMPCertificate
   --   id-it-signKeyPairTypes OBJECT IDENTIFIER ::= {id-it 2}
   --      SignKeyPairTypesValue   ::= SEQUENCE SIZE (1..MAX) OF
   --                                        AlgorithmIdentifier
   --   id-it-encKeyPairTypes  OBJECT IDENTIFIER ::= {id-it 3}
   --      EncKeyPairTypesValue    ::= SEQUENCE SIZE (1..MAX) OF
   --                                        AlgorithmIdentifier
   --   id-it-preferredSymmAlg OBJECT IDENTIFIER ::= {id-it 4}
   --      PreferredSymmAlgValue   ::= AlgorithmIdentifier
   --   id-it-caKeyUpdateInfo  OBJECT IDENTIFIER ::= {id-it 5}
   --      CAKeyUpdateInfoValue    ::= CAKeyUpdAnnContent
   --   id-it-currentCRL       OBJECT IDENTIFIER ::= {id-it 6}
   --      CurrentCRLValue         ::= CertificateList
   --   id-it-unsupportedOIDs  OBJECT IDENTIFIER ::= {id-it 7}
   --      UnsupportedOIDsValue    ::= SEQUENCE SIZE (1..MAX) OF
   --                                          OBJECT IDENTIFIER
   --   id-it-keyPairParamReq  OBJECT IDENTIFIER ::= {id-it 10}
   --      KeyPairParamReqValue    ::= OBJECT IDENTIFIER
   --   id-it-keyPairParamRep  OBJECT IDENTIFIER ::= {id-it 11}
   --      KeyPairParamRepValue    ::= AlgorithmIdentifier
   --   id-it-revPassphrase    OBJECT IDENTIFIER ::= {id-it 12}
   --      RevPassphraseValue      ::= EncryptedKey
   --      - Changed from Encrypted Value to EncryptedKey as a CHOICE
   --      - of EncryptedValue and EnvelopedData due to the changes
   --      - made in CMP Updates [RFC9480].
   --      - Using the choice EncryptedValue is bit-compatible to the
   --      - syntax without this change.
   --   id-it-implicitConfirm  OBJECT IDENTIFIER ::= {id-it 13}
   --      ImplicitConfirmValue    ::= NULL
   --   id-it-confirmWaitTime  OBJECT IDENTIFIER ::= {id-it 14}
   --      ConfirmWaitTimeValue    ::= GeneralizedTime
   --   id-it-origPKIMessage   OBJECT IDENTIFIER ::= {id-it 15}
   --      OrigPKIMessageValue     ::= PKIMessages
   --   id-it-suppLangTags     OBJECT IDENTIFIER ::= {id-it 16}
   --      SuppLangTagsValue       ::= SEQUENCE OF UTF8String
   --   id-it-caCerts          OBJECT IDENTIFIER ::= {id-it 17}
   --      CaCertsValue            ::= SEQUENCE SIZE (1..MAX) OF
   --                                             CMPCertificate
   --      - id-it-caCerts added in CMP Updates [RFC9480]
   --   id-it-rootCaKeyUpdate  OBJECT IDENTIFIER ::= {id-it 18}
   --      RootCaKeyUpdateValue    ::= RootCaKeyUpdateContent
   --      - id-it-rootCaKeyUpdate added in CMP Updates [RFC9480]
   --   id-it-certReqTemplate  OBJECT IDENTIFIER ::= {id-it 19}
   --      CertReqTemplateValue    ::= CertReqTemplateContent
   --      - id-it-certReqTemplate added in CMP Updates [RFC9480]
   --   id-it-rootCaCert       OBJECT IDENTIFIER ::= {id-it 20}
   --      RootCaCertValue         ::= CMPCertificate
   --      - id-it-rootCaCert added in CMP Updates [RFC9480]
   --   id-it-certProfile      OBJECT IDENTIFIER ::= {id-it 21}
   --      CertProfileValue        ::= SEQUENCE SIZE (1..MAX) OF
   --                                                 UTF8String
   --      - id-it-certProfile added in CMP Updates [RFC9480]
   --   id-it-crlStatusList    OBJECT IDENTIFIER ::= {id-it 22}
   --   CRLStatusListValue         ::= SEQUENCE SIZE (1..MAX) OF
   --                                                  CRLStatus
   --      - id-it-crlStatusList added in CMP Updates [RFC9480]
   --   id-it-crls             OBJECT IDENTIFIER ::= {id-it 23}
   --   CRLsValue                  ::= SEQUENCE SIZE (1..MAX) OF
   --                                            CertificateList
   --      - id-it-crls added in CMP Updates [RFC9480]
   --
   -- where
   --
   --   id-pkix OBJECT IDENTIFIER ::= {
   --      iso(1) identified-organization(3)
   --      dod(6) internet(1) security(5) mechanisms(5) pkix(7)}
   -- and
   --   id-it   OBJECT IDENTIFIER ::= {id-pkix 4}
   --
   --
   -- This construct MAY also be used to define new PKIX Certificate
   -- Management Protocol request and response messages or general-
   -- purpose (e.g., announcement) messages for future needs or for
   -- specific environments.

   GenMsgContent ::= SEQUENCE OF InfoTypeAndValue

   -- May be sent by EE, RA, or CA (depending on message content).
   -- The OPTIONAL infoValue parameter of InfoTypeAndValue will
   -- typically be omitted for some of the examples given above.
   -- The receiver is free to ignore any contained OIDs that it
   -- does not recognize.  If sent from EE to CA, the empty set
   -- indicates that the CA may send
   -- any/all information that it wishes.

   GenRepContent ::= SEQUENCE OF InfoTypeAndValue
   -- The receiver MAY ignore any contained OIDs that it does not
   -- recognize.

   ErrorMsgContent ::= SEQUENCE {
       pKIStatusInfo          PKIStatusInfo,
       errorCode              INTEGER           OPTIONAL,
       -- implementation-specific error codes
       errorDetails           PKIFreeText       OPTIONAL
       -- implementation-specific error details
   }

   PollReqContent ::= SEQUENCE OF SEQUENCE {
       certReqId              INTEGER
   }

   PollRepContent ::= SEQUENCE OF SEQUENCE {
       certReqId              INTEGER,
       checkAfter             INTEGER,  -- time in seconds
       reason                 PKIFreeText OPTIONAL
   }

   --
   -- Extended key usage extension for PKI entities used in CMP
   -- operations, added due to the changes made in
   -- CMP Updates [RFC9480]
   -- The EKUs for the CA and RA are reused from CMC, as defined in
   -- [RFC6402]
   --

   -- id-kp-cmcCA OBJECT IDENTIFIER ::= { id-kp 27 }
   -- id-kp-cmcRA OBJECT IDENTIFIER ::= { id-kp 28 }
   id-kp-cmKGA OBJECT IDENTIFIER ::= { id-kp 32 }

   -- There is no 1988 ASN.1 module of PKCS #9 available to import the
   -- syntax of the localKeyId attribute type and value from. Therefore,
   -- the syntax is added here as needed for the updates made in
   -- CMP Updates [RFC9480].

   pkcs-9 OBJECT IDENTIFIER ::= {iso(1) member-body(2) us(840)
                                 rsadsi(113549) pkcs(1) 9}

   pkcs-9-at-localKeyId OBJECT IDENTIFIER ::= {pkcs-9 21}

   LocalKeyIdValue ::= OCTET STRING

   END -- of CMP module

A.2.  Update to RFC 5912 - 2002 ASN.1 Module

   This section contains the updated 2002 ASN.1 module for [RFC5912].
   This module replaces the module in Section 9 of [RFC5912].  The
   module contains those changes to the normative ASN.1 module from
   Appendix F of [RFC4210] that were to update to the 2002 ASN.1
   standard done in [RFC5912], as well as changes made in this document.

   PKIXCMP-2021
       { iso(1) identified-organization(3) dod(6) internet(1)
       security(5) mechanisms(5) pkix(7) id-mod(0)
       id-mod-cmp2021-02(100) }
   DEFINITIONS EXPLICIT TAGS ::=
   BEGIN
   IMPORTS

   AttributeSet{}, SingleAttribute{}, Extensions{}, EXTENSION, ATTRIBUTE
   FROM PKIX-CommonTypes-2009
       {iso(1) identified-organization(3) dod(6) internet(1) security(5)
       mechanisms(5) pkix(7) id-mod(0) id-mod-pkixCommon-02(57)}

   AlgorithmIdentifier{}, SIGNATURE-ALGORITHM, ALGORITHM,
       DIGEST-ALGORITHM, MAC-ALGORITHM
   FROM AlgorithmInformation-2009
       {iso(1) identified-organization(3) dod(6) internet(1) security(5)
       mechanisms(5) pkix(7) id-mod(0)
       id-mod-algorithmInformation-02(58)}

   Certificate, CertificateList, Time, id-kp
   FROM PKIX1Explicit-2009
       {iso(1) identified-organization(3) dod(6) internet(1) security(5)
       mechanisms(5) pkix(7) id-mod(0) id-mod-pkix1-explicit-02(51)}

   DistributionPointName, GeneralNames, GeneralName, KeyIdentifier
   FROM PKIX1Implicit-2009
       {iso(1) identified-organization(3) dod(6) internet(1) security(5)
       mechanisms(5) pkix(7) id-mod(0) id-mod-pkix1-implicit-02(59)}

   CertTemplate, PKIPublicationInfo, EncryptedKey, CertId,
       CertReqMessages, Controls, RegControlSet, id-regCtrl
   FROM PKIXCRMF-2009
       { iso(1) identified-organization(3) dod(6) internet(1)
       security(5) mechanisms(5) pkix(7) id-mod(0)
       id-mod-crmf2005-02(55) }
       -- The import of EncryptedKey is added due to the updates made
       -- in CMP Updates [RFC9480]. EncryptedValue does not need to
       -- be imported anymore and is therefore removed here.

   -- See also the behavioral clarifications to CRMF codified in
   -- Appendix C of this specification.

   CertificationRequest
   FROM PKCS-10
       {iso(1) identified-organization(3) dod(6) internet(1) security(5)
       mechanisms(5) pkix(7) id-mod(0) id-mod-pkcs10-2009(69)}
   -- (specified in [RFC2986] with 1993 ASN.1 syntax and IMPLICIT
   -- tags).  Alternatively, implementers may directly include
   -- the syntax of [RFC2986] in this module.

   localKeyId
   FROM PKCS-9
       {iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
       modules(0) pkcs-9(1)}
       -- The import of localKeyId is added due to the updates made in
       -- CMP Updates [RFC9480].

   EnvelopedData, SignedData
   FROM CryptographicMessageSyntax-2009
       {iso(1) member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-9(9)
       smime(16) modules(0) id-mod-cms-2004-02(41)}
       -- The import of EnvelopedData and SignedData is added due to
       -- the updates made in CMP Updates [RFC9480].
   ;

   -- The rest of the module contains locally defined OIDs and
   -- constructs:

   CMPCertificate ::= CHOICE { x509v3PKCert Certificate, ... }
   -- This syntax, while bits-on-the-wire compatible with the
   -- standard X.509 definition of "Certificate", allows the
   -- possibility of future certificate types (such as X.509
   -- attribute certificates, card-verifiable
   -- certificates, or other kinds of certificates) within this
   -- Certificate Management Protocol, should a need ever arise to
   -- support such generality.  Those implementations that do not
   -- foresee a need to ever support other certificate types MAY, if
   -- they wish, comment out the above structure and "uncomment" the
   -- following one prior to compiling this ASN.1 module.  (Note that
   -- interoperability with implementations that don't do this will be
   -- unaffected by this change.)

   -- CMPCertificate ::= Certificate

   PKIMessage ::= SEQUENCE {
       header           PKIHeader,
       body             PKIBody,
       protection   [0] PKIProtection OPTIONAL,
       extraCerts   [1] SEQUENCE SIZE (1..MAX) OF CMPCertificate
                     OPTIONAL }

   PKIMessages ::= SEQUENCE SIZE (1..MAX) OF PKIMessage

   PKIHeader ::= SEQUENCE {
       pvno                INTEGER     { cmp1999(1), cmp2000(2),
                                         cmp2012(3) },
       sender              GeneralName,
       -- identifies the sender
       recipient           GeneralName,
       -- identifies the intended recipient
       messageTime     [0] GeneralizedTime         OPTIONAL,
       -- time of production of this message (used when the sender
       -- believes that the transport will be "suitable", i.e.,
       -- that the time will still be meaningful upon receipt)
       protectionAlg   [1] AlgorithmIdentifier{ALGORITHM, {...}}
                               OPTIONAL,
       -- algorithm used for the calculation of protection bits
       senderKID       [2] KeyIdentifier           OPTIONAL,
       recipKID        [3] KeyIdentifier           OPTIONAL,
       -- to identify specific keys used for protection
       transactionID   [4] OCTET STRING            OPTIONAL,
       -- identifies the transaction, i.e., this will be the same in
       -- corresponding request, response, certConf, and PKIConf
       -- messages
       senderNonce     [5] OCTET STRING            OPTIONAL,
       recipNonce      [6] OCTET STRING            OPTIONAL,
       -- nonces used to provide replay protection, senderNonce
       -- is inserted by the creator of this message; recipNonce
       -- is a nonce previously inserted in a related message by
       -- the intended recipient of this message.
       freeText        [7] PKIFreeText             OPTIONAL,
       -- this may be used to indicate context-specific instructions
       -- (this field is intended for human consumption)
       generalInfo     [8] SEQUENCE SIZE (1..MAX) OF
                           InfoTypeAndValue     OPTIONAL
       -- this may be used to convey context-specific information
       -- (this field not primarily intended for human consumption)
   }

   PKIFreeText ::= SEQUENCE SIZE (1..MAX) OF UTF8String
       -- text encoded as a UTF-8 string [RFC3629]

   PKIBody ::= CHOICE {       -- message-specific body elements
       ir       [0]  CertReqMessages,        --Initialization Request
       ip       [1]  CertRepMessage,         --Initialization Response
       cr       [2]  CertReqMessages,        --Certification Request
       cp       [3]  CertRepMessage,         --Certification Response
       p10cr    [4]  CertificationRequest,   --imported from [RFC2986]
       popdecc  [5]  POPODecKeyChallContent, --pop Challenge
       popdecr  [6]  POPODecKeyRespContent,  --pop Response
       kur      [7]  CertReqMessages,        --Key Update Request
       kup      [8]  CertRepMessage,         --Key Update Response
       krr      [9]  CertReqMessages,        --Key Recovery Request
       krp      [10] KeyRecRepContent,       --Key Recovery Response
       rr       [11] RevReqContent,          --Revocation Request
       rp       [12] RevRepContent,          --Revocation Response
       ccr      [13] CertReqMessages,        --Cross-Cert. Request
       ccp      [14] CertRepMessage,         --Cross-Cert. Response
       ckuann   [15] CAKeyUpdAnnContent,     --CA Key Update Ann.
       cann     [16] CertAnnContent,         --Certificate Ann.
       rann     [17] RevAnnContent,          --Revocation Ann.
       crlann   [18] CRLAnnContent,          --CRL Announcement
       pkiconf  [19] PKIConfirmContent,      --Confirmation
       nested   [20] NestedMessageContent,   --Nested Message
       genm     [21] GenMsgContent,          --General Message
       genp     [22] GenRepContent,          --General Response
       error    [23] ErrorMsgContent,        --Error Message
       certConf [24] CertConfirmContent,     --Certificate Confirm
       pollReq  [25] PollReqContent,         --Polling Request
       pollRep  [26] PollRepContent          --Polling Response
   }

   PKIProtection ::= BIT STRING

   ProtectedPart ::= SEQUENCE {
       header    PKIHeader,
       body      PKIBody }

   id-PasswordBasedMac OBJECT IDENTIFIER ::= { iso(1) member-body(2)
       usa(840) nt(113533) nsn(7) algorithms(66) 13 }
   PBMParameter ::= SEQUENCE {
       salt                OCTET STRING,
       -- Note: Implementations MAY wish to limit acceptable sizes
       -- of this string to values appropriate for their environment
       -- in order to reduce the risk of denial-of-service attacks.
       owf                 AlgorithmIdentifier{DIGEST-ALGORITHM, {...}},
       -- AlgId for a One-Way Function
       iterationCount      INTEGER,
       -- number of times the OWF is applied
       -- Note: Implementations MAY wish to limit acceptable sizes
       -- of this integer to values appropriate for their environment
       -- in order to reduce the risk of denial-of-service attacks.
       mac                 AlgorithmIdentifier{MAC-ALGORITHM, {...}}
       -- the MAC AlgId (e.g., HMAC-SHA256, AES-GMAC [RFC9481],
       -- or HMAC [RFC2104, RFC2202])
   }

   id-DHBasedMac OBJECT IDENTIFIER ::= { iso(1) member-body(2)
       usa(840) nt(113533) nsn(7) algorithms(66) 30 }
   DHBMParameter ::= SEQUENCE {
       owf                 AlgorithmIdentifier{DIGEST-ALGORITHM, {...}},
       -- AlgId for a One-Way Function
       mac                 AlgorithmIdentifier{MAC-ALGORITHM, {...}}
       -- the MAC AlgId (e.g., HMAC-SHA256, AES-GMAC [RFC9481],
       -- or HMAC [RFC2104, RFC2202])
   }

   PKIStatus ::= INTEGER {
       accepted               (0),
       -- you got exactly what you asked for
       grantedWithMods        (1),
       -- you got something like what you asked for; the
       -- requester is responsible for ascertaining the differences
       rejection              (2),
       -- you don't get it, more information elsewhere in the message
       waiting                (3),
       -- the request body part has not yet been processed; expect to
       -- hear more later (note: proper handling of this status
       -- response MAY use the polling req/rep PKIMessages specified
       -- in Section 5.3.22 of [RFC4210]; alternatively, polling in the
       -- underlying transport layer MAY have some utility in this
       -- regard)
       revocationWarning      (4),
       -- this message contains a warning that a revocation is
       -- imminent
       revocationNotification (5),
       -- notification that a revocation has occurred
       keyUpdateWarning       (6)
       -- update already done for the oldCertId specified in
       -- CertReqMsg
   }

   PKIFailureInfo ::= BIT STRING {
   -- since we can fail in more than one way!
   -- More codes may be added in the future if/when required.
       badAlg              (0),
       -- unrecognized or unsupported algorithm identifier
       badMessageCheck     (1),
       -- integrity check failed (e.g., signature did not verify)
       badRequest          (2),
       -- transaction not permitted or supported
       badTime             (3),
       -- messageTime was not sufficiently close to the system time,
       -- as defined by local policy
       badCertId           (4),
       -- no certificate could be found matching the provided criteria
       badDataFormat       (5),
       -- the data submitted has the wrong format
       wrongAuthority      (6),
       -- the authority indicated in the request is different from the
       -- one creating the response token
       incorrectData       (7),
       -- the requester's data is incorrect (for notary services)
       missingTimeStamp    (8),
       -- when the timestamp is missing but should be there
       -- (by policy)
       badPOP              (9),
       -- the proof-of-possession failed
       certRevoked         (10),
       -- the certificate has already been revoked
       certConfirmed       (11),
       -- the certificate has already been confirmed
       wrongIntegrity      (12),
       -- not valid integrity, based on the password instead of the
       -- signature or vice versa
       badRecipientNonce   (13),
       -- not valid recipient nonce, either missing or wrong value
       timeNotAvailable    (14),
       -- the TSA's time source is not available
       unacceptedPolicy    (15),
       -- the requested TSA policy is not supported by the TSA
       unacceptedExtension (16),
       -- the requested extension is not supported by the TSA
       addInfoNotAvailable (17),
       -- the additional information requested could not be
       -- understood or is not available
       badSenderNonce      (18),
       -- not valid sender nonce, either missing or wrong size
       badCertTemplate     (19),
       -- not valid cert. template or missing mandatory information
       signerNotTrusted    (20),
       -- signer of the message unknown or not trusted
       transactionIdInUse  (21),
       -- the transaction identifier is already in use
       unsupportedVersion  (22),
       -- the version of the message is not supported
       notAuthorized       (23),
       -- the sender was not authorized to make the preceding
       -- request or perform the preceding action
       systemUnavail       (24),
       -- the request cannot be handled due to system unavailability
       systemFailure       (25),
       -- the request cannot be handled due to system failure
       duplicateCertReq    (26)
       -- the certificate cannot be issued because a duplicate
       -- certificate already exists
   }

   PKIStatusInfo ::= SEQUENCE {
       status        PKIStatus,
       statusString  PKIFreeText     OPTIONAL,
       failInfo      PKIFailureInfo  OPTIONAL }

   OOBCert ::= CMPCertificate

   OOBCertHash ::= SEQUENCE {
       hashAlg     [0] AlgorithmIdentifier{DIGEST-ALGORITHM, {...}}
                           OPTIONAL,
       certId      [1] CertId                  OPTIONAL,
       hashVal         BIT STRING
       -- hashVal is calculated over the DER encoding of the
       -- self-signed certificate with the identifier certID.
   }

   POPODecKeyChallContent ::= SEQUENCE OF Challenge
   -- One Challenge per encryption key certification request (in the
   -- same order as these requests appear in CertReqMessages)

   Challenge ::= SEQUENCE {
       owf                 AlgorithmIdentifier{DIGEST-ALGORITHM, {...}}
                               OPTIONAL,
       -- MUST be present in the first Challenge; MAY be omitted in
       -- any subsequent Challenge in POPODecKeyChallContent (if
       -- omitted, then the owf used in the immediately preceding
       -- Challenge is to be used)
       witness             OCTET STRING,
       -- the result of applying the One-Way Function (owf) to a
       -- randomly generated INTEGER, A (Note that a different
       -- INTEGER MUST be used for each Challenge.)
       challenge           OCTET STRING
       -- the encryption (under the public key for which the cert.
       -- request is being made) of Rand
   }

   -- Rand was added in CMP Updates [RFC9480]

   Rand ::= SEQUENCE {
   -- Rand is encrypted under the public key to form the challenge
   -- in POPODecKeyChallContent
      int                  INTEGER,
      -- the randomly generated INTEGER A (above)
      sender               GeneralName
      -- the sender's name (as included in PKIHeader)
   }

   POPODecKeyRespContent ::= SEQUENCE OF INTEGER
   -- One INTEGER per encryption key certification request (in the
   -- same order as these requests appear in CertReqMessages).  The
   -- retrieved INTEGER A (above) is returned to the sender of the
   -- corresponding Challenge.

   CertRepMessage ::= SEQUENCE {
       caPubs       [1] SEQUENCE SIZE (1..MAX) OF CMPCertificate
                     OPTIONAL,
       response         SEQUENCE OF CertResponse }

   CertResponse ::= SEQUENCE {
       certReqId           INTEGER,
       -- to match this response with the corresponding request (a value
       -- of -1 is to be used if certReqId is not specified in the
       -- corresponding request, which can only be a p10cr)
       status              PKIStatusInfo,
       certifiedKeyPair    CertifiedKeyPair    OPTIONAL,
       rspInfo             OCTET STRING        OPTIONAL
       -- analogous to the id-regInfo-utf8Pairs string defined
       -- for regInfo in CertReqMsg [RFC4211]
   }

   CertifiedKeyPair ::= SEQUENCE {
       certOrEncCert       CertOrEncCert,
       privateKey      [0] EncryptedKey      OPTIONAL,
       -- See [RFC4211] for comments on encoding.
       -- Changed from Encrypted Value to EncryptedKey as a CHOICE of
       -- EncryptedValue and EnvelopedData due to the changes made in
       -- CMP Updates [RFC9480].
       -- Using the choice EncryptedValue is bit-compatible to the
       -- syntax without this change.
       publicationInfo [1] PKIPublicationInfo  OPTIONAL }

   CertOrEncCert ::= CHOICE {
       certificate     [0] CMPCertificate,
       encryptedCert   [1] EncryptedKey
       -- Changed from Encrypted Value to EncryptedKey as a CHOICE of
       -- EncryptedValue and EnvelopedData due to the changes made in
       -- CMP Updates [RFC9480].
       -- Using the choice EncryptedValue is bit-compatible to the
       -- syntax without this change.
   }

   KeyRecRepContent ::= SEQUENCE {
       status                  PKIStatusInfo,
       newSigCert          [0] CMPCertificate OPTIONAL,
       caCerts             [1] SEQUENCE SIZE (1..MAX) OF
                                        CMPCertificate OPTIONAL,
       keyPairHist         [2] SEQUENCE SIZE (1..MAX) OF
                                        CertifiedKeyPair OPTIONAL }

   RevReqContent ::= SEQUENCE OF RevDetails

   RevDetails ::= SEQUENCE {
       certDetails         CertTemplate,
       -- allows the requester to specify as much as they can about
       -- the cert. for which revocation is requested
       -- (e.g., for cases in which serialNumber is not available)
       crlEntryDetails     Extensions{{...}}    OPTIONAL
       -- requested crlEntryExtensions
   }

   RevRepContent ::= SEQUENCE {
       status       SEQUENCE SIZE (1..MAX) OF PKIStatusInfo,
       -- in the same order as was sent in RevReqContent
       revCerts [0] SEQUENCE SIZE (1..MAX) OF CertId OPTIONAL,
       -- IDs for which revocation was requested
       -- (same order as status)
       crls     [1] SEQUENCE SIZE (1..MAX) OF CertificateList OPTIONAL
       -- the resulting CRLs (there may be more than one)
   }

   CAKeyUpdAnnContent ::= SEQUENCE {
       oldWithNew   CMPCertificate, -- old pub signed with new priv
       newWithOld   CMPCertificate, -- new pub signed with old priv
       newWithNew   CMPCertificate  -- new pub signed with new priv
   }

   CertAnnContent ::= CMPCertificate

   RevAnnContent ::= SEQUENCE {
       status              PKIStatus,
       certId              CertId,
       willBeRevokedAt     GeneralizedTime,
       badSinceDate        GeneralizedTime,
       crlDetails          Extensions{{...}}  OPTIONAL
       -- extra CRL details (e.g., crl number, reason, location, etc.)
   }

   CRLAnnContent ::= SEQUENCE OF CertificateList
   PKIConfirmContent ::= NULL

   NestedMessageContent ::= PKIMessages

   -- CertReqTemplateContent, AttributeTypeAndValue,
   -- ExpandedRegControlSet, id-regCtrl-altCertTemplate,
   -- AltCertTemplate, regCtrl-algId, id-regCtrl-algId, AlgIdCtrl,
   -- regCtrl-rsaKeyLen, id-regCtrl-rsaKeyLen, and RsaKeyLenCtrl
   -- were added in CMP Updates [RFC9480]

   CertReqTemplateContent ::= SEQUENCE {
      certTemplate           CertTemplate,
      -- prefilled certTemplate structure elements
      -- The SubjectPublicKeyInfo field in the certTemplate MUST NOT
      -- be used.
      keySpec                Controls OPTIONAL
      -- MAY be used to specify supported algorithms
      -- Controls  ::= SEQUENCE SIZE (1..MAX) OF AttributeTypeAndValue
      -- as specified in CRMF [RFC4211]
      }

   AttributeTypeAndValue ::= SingleAttribute{{ ... }}

   ExpandedRegControlSet ATTRIBUTE ::= { RegControlSet |
      regCtrl-altCertTemplate | regCtrl-algId | regCtrl-rsaKeyLen, ... }

   regCtrl-altCertTemplate ATTRIBUTE ::=
      { TYPE AltCertTemplate IDENTIFIED BY id-regCtrl-altCertTemplate }

   id-regCtrl-altCertTemplate OBJECT IDENTIFIER ::= { id-regCtrl 7 }

   AltCertTemplate ::= AttributeTypeAndValue
      -- specifies a template for a certificate other than an X.509v3
      -- public key certificate

   regCtrl-algId ATTRIBUTE ::=
      { TYPE AlgIdCtrl IDENTIFIED BY id-regCtrl-algId }

   id-regCtrl-algId OBJECT IDENTIFIER ::= { id-regCtrl 11 }

   AlgIdCtrl ::= AlgorithmIdentifier{ALGORITHM, {...}}
      -- SHALL be used to specify supported algorithms other than RSA

   regCtrl-rsaKeyLen ATTRIBUTE ::=
      { TYPE RsaKeyLenCtrl IDENTIFIED BY id-regCtrl-rsaKeyLen }

   id-regCtrl-rsaKeyLen OBJECT IDENTIFIER ::= { id-regCtrl 12 }

   RsaKeyLenCtrl ::= INTEGER (1..MAX)
      -- SHALL be used to specify supported RSA key lengths

   -- RootCaKeyUpdateContent, CRLSource, and CRLStatus were added in
   -- CMP Updates [RFC9480]

   RootCaKeyUpdateContent ::= SEQUENCE {
      newWithNew       CMPCertificate,
      -- new root CA certificate
      newWithOld   [0] CMPCertificate OPTIONAL,
      -- X.509 certificate containing the new public root CA key
      -- signed with the old private root CA key
      oldWithNew   [1] CMPCertificate OPTIONAL
      -- X.509 certificate containing the old public root CA key
      -- signed with the new private root CA key
      }

   CRLSource ::= CHOICE {
      dpn          [0] DistributionPointName,
      issuer       [1] GeneralNames }

   CRLStatus ::= SEQUENCE {
      source       CRLSource,
      thisUpdate   Time OPTIONAL }

   INFO-TYPE-AND-VALUE ::= TYPE-IDENTIFIER

   InfoTypeAndValue ::= SEQUENCE {
       infoType    INFO-TYPE-AND-VALUE.
                       &id({SupportedInfoSet}),
       infoValue   INFO-TYPE-AND-VALUE.
                       &Type({SupportedInfoSet}{@infoType}) }

   SupportedInfoSet INFO-TYPE-AND-VALUE ::= { ... }

   -- Example InfoTypeAndValue contents include, but are not limited
   -- to, the following (uncomment in this ASN.1 module and use as
   -- appropriate for a given environment):
   --
   --   id-it-caProtEncCert    OBJECT IDENTIFIER ::= {id-it 1}
   --      CAProtEncCertValue      ::= CMPCertificate
   --   id-it-signKeyPairTypes OBJECT IDENTIFIER ::= {id-it 2}
   --      SignKeyPairTypesValue   ::= SEQUENCE SIZE (1..MAX) OF
   --                                      AlgorithmIdentifier{{...}}
   --   id-it-encKeyPairTypes  OBJECT IDENTIFIER ::= {id-it 3}
   --      EncKeyPairTypesValue    ::= SEQUENCE SIZE (1..MAX) OF
   --                                      AlgorithmIdentifier{{...}}
   --   id-it-preferredSymmAlg OBJECT IDENTIFIER ::= {id-it 4}
   --      PreferredSymmAlgValue   ::= AlgorithmIdentifier{{...}}
   --   id-it-caKeyUpdateInfo  OBJECT IDENTIFIER ::= {id-it 5}
   --      CAKeyUpdateInfoValue    ::= CAKeyUpdAnnContent
   --   id-it-currentCRL       OBJECT IDENTIFIER ::= {id-it 6}
   --      CurrentCRLValue         ::= CertificateList
   --   id-it-unsupportedOIDs  OBJECT IDENTIFIER ::= {id-it 7}
   --      UnsupportedOIDsValue    ::= SEQUENCE SIZE (1..MAX) OF
   --                                          OBJECT IDENTIFIER
   --   id-it-keyPairParamReq  OBJECT IDENTIFIER ::= {id-it 10}
   --      KeyPairParamReqValue    ::= OBJECT IDENTIFIER
   --   id-it-keyPairParamRep  OBJECT IDENTIFIER ::= {id-it 11}
   --      KeyPairParamRepValue    ::= AlgorithmIdentifier{{...}}
   --   id-it-revPassphrase    OBJECT IDENTIFIER ::= {id-it 12}
   --      RevPassphraseValue      ::= EncryptedKey
   --      - Changed from Encrypted Value to EncryptedKey as a CHOICE
   --      - of EncryptedValue and EnvelopedData due to the changes
   --      - made in CMP Updates [RFC9480]
   --      - Using the choice EncryptedValue is bit-compatible to
   --      - the syntax without this change
   --   id-it-implicitConfirm  OBJECT IDENTIFIER ::= {id-it 13}
   --      ImplicitConfirmValue    ::= NULL
   --   id-it-confirmWaitTime  OBJECT IDENTIFIER ::= {id-it 14}
   --      ConfirmWaitTimeValue    ::= GeneralizedTime
   --   id-it-origPKIMessage   OBJECT IDENTIFIER ::= {id-it 15}
   --      OrigPKIMessageValue     ::= PKIMessages
   --   id-it-suppLangTags     OBJECT IDENTIFIER ::= {id-it 16}
   --      SuppLangTagsValue       ::= SEQUENCE OF UTF8String
   --   id-it-caCerts          OBJECT IDENTIFIER ::= {id-it 17}
   --      CaCertsValue            ::= SEQUENCE SIZE (1..MAX) OF
   --                                             CMPCertificate
   --      - id-it-caCerts added in CMP Updates [RFC9480]
   --   id-it-rootCaKeyUpdate  OBJECT IDENTIFIER ::= {id-it 18}
   --      RootCaKeyUpdateValue    ::= RootCaKeyUpdateContent
   --      - id-it-rootCaKeyUpdate added in CMP Updates [RFC9480]
   --   id-it-certReqTemplate  OBJECT IDENTIFIER ::= {id-it 19}
   --      CertReqTemplateValue    ::= CertReqTemplateContent
   --      - id-it-certReqTemplate added in CMP Updates [RFC9480]
   --   id-it-rootCaCert       OBJECT IDENTIFIER ::= {id-it 20}
   --      RootCaCertValue         ::= CMPCertificate
   --      - id-it-rootCaCert added in CMP Updates [RFC9480]
   --   id-it-certProfile      OBJECT IDENTIFIER ::= {id-it 21}
   --      CertProfileValue        ::= SEQUENCE SIZE (1..MAX) OF
   --                                                 UTF8String
   --      - id-it-certProfile added in CMP Updates [RFC9480]
   --   id-it-crlStatusList    OBJECT IDENTIFIER ::= {id-it 22}
   --   CRLStatusListValue         ::= SEQUENCE SIZE (1..MAX) OF
   --                                                  CRLStatus
   --      - id-it-crlStatusList added in CMP Updates [RFC9480]
   --   id-it-crls             OBJECT IDENTIFIER ::= {id-it 23}
   --   CRLsValue                  ::= SEQUENCE SIZE (1..MAX) OF
   --                                            CertificateList
   --      - id-it-crls added in CMP Updates [RFC9480]
   --
   -- where
   --
   --   id-pkix OBJECT IDENTIFIER ::= {
   --      iso(1) identified-organization(3)
   --      dod(6) internet(1) security(5) mechanisms(5) pkix(7)}
   -- and
   --   id-it   OBJECT IDENTIFIER ::= {id-pkix 4}
   --
   --
   -- This construct MAY also be used to define new PKIX Certificate
   -- Management Protocol request and response messages or general-
   -- purpose (e.g., announcement) messages for future needs or for
   -- specific environments.

   GenMsgContent ::= SEQUENCE OF InfoTypeAndValue

   -- May be sent by EE, RA, or CA (depending on message content).
   -- The OPTIONAL infoValue parameter of InfoTypeAndValue will
   -- typically be omitted for some of the examples given above.
   -- The receiver is free to ignore any contained OIDs that it
   -- does not recognize.  If sent from EE to CA, the empty set
   -- indicates that the CA may send
   -- any/all information that it wishes.

   GenRepContent ::= SEQUENCE OF InfoTypeAndValue
   -- The receiver MAY ignore any contained OIDs that it does not
   -- recognize.

   ErrorMsgContent ::= SEQUENCE {
       pKIStatusInfo          PKIStatusInfo,
       errorCode              INTEGER           OPTIONAL,
       -- implementation-specific error codes
       errorDetails           PKIFreeText       OPTIONAL
       -- implementation-specific error details
   }

   CertConfirmContent ::= SEQUENCE OF CertStatus

   CertStatus ::= SEQUENCE {
       certHash    OCTET STRING,
       -- the hash of the certificate, using the same hash algorithm
       -- as is used to create and verify the certificate signature
       certReqId   INTEGER,
       -- to match this confirmation with the corresponding req/rep
       statusInfo  PKIStatusInfo OPTIONAL,
       hashAlg [0] AlgorithmIdentifier{DIGEST-ALGORITHM, {...}} OPTIONAL
       -- the hash algorithm to use for calculating certHash
       -- SHOULD NOT be used in all cases where the AlgorithmIdentifier
       -- of the certificate signature specifies a hash algorithm
      }

   PollReqContent ::= SEQUENCE OF SEQUENCE {
       certReqId              INTEGER }

   PollRepContent ::= SEQUENCE OF SEQUENCE {
       certReqId              INTEGER,
       checkAfter             INTEGER,  -- time in seconds
       reason                 PKIFreeText OPTIONAL }

   --
   -- Extended key usage extension for PKI entities used in CMP
   -- operations, added due to the changes made in
   -- CMP Updates [RFC9480]
   -- The EKUs for the CA and RA are reused from CMC, as defined in
   -- [RFC6402]
   --

   -- id-kp-cmcCA OBJECT IDENTIFIER ::= { id-kp 27 }
   -- id-kp-cmcRA OBJECT IDENTIFIER ::= { id-kp 28 }
   id-kp-cmKGA OBJECT IDENTIFIER ::= { id-kp 32 }

   END

Acknowledgements

   Special thanks goes to Jim Schaad for his guidance and the
   inspiration to structure and write this document like [RFC6402],
   which updates CMC.  Special thanks also goes to Russ Housley, Lijun
   Liao, Martin Peylo, and Tomas Gustavsson for reviewing and providing
   valuable suggestions on improving this document.

   We also thank all reviewers of this document for their valuable
   feedback.

Authors' Addresses

   Hendrik Brockhaus
   Siemens
   Werner-von-Siemens-Strasse 1
   80333 Munich
   Germany
   Email: hendrik.brockhaus@siemens.com
   URI:   https://www.siemens.com

   David von Oheimb
   Siemens
   Werner-von-Siemens-Strasse 1
   80333 Munich
   Germany
   Email: david.von.oheimb@siemens.com
   URI:   https://www.siemens.com

   John Gray
   Entrust
   1187 Park Place
   Minneapolis, MN 55379
   United States of America
   Email: john.gray@entrust.com
   URI:   https://www.entrust.com