



LAMPS Working Group                                    H. Brockhaus, Ed.
Internet-Draft                                               H. Aschauer
Updates: 4210 (if approved)                                      Siemens
Intended status: Standards Track                            M. Ounsworth
Expires: 4 December 2022                                         J. Gray
                                                                 Entrust
                                                             2 June 2022


            Certificate Management Protocol (CMP) Algorithms
                   draft-ietf-lamps-cmp-algorithms-15

Abstract

   This document describes the conventions for using several
   cryptographic algorithms with the Certificate Management Protocol
   (CMP).  CMP is used to enroll and further manage the lifecycle of
   X.509 certificates.  This document also updates the algorithm use
   profile from RFC 4210 Appendix D.2.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at https://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on 4 December 2022.

Copyright Notice

   Copyright (c) 2022 IETF Trust and the persons identified as the
   document authors.  All rights reserved.










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   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  . . . . . . . . . . . . . . . . . . . . . . . .   3
     1.1.  Terminology . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  Message Digest Algorithms . . . . . . . . . . . . . . . . . .   3
     2.1.  SHA2  . . . . . . . . . . . . . . . . . . . . . . . . . .   4
     2.2.  SHAKE . . . . . . . . . . . . . . . . . . . . . . . . . .   4
   3.  Signature Algorithms  . . . . . . . . . . . . . . . . . . . .   5
     3.1.  RSA . . . . . . . . . . . . . . . . . . . . . . . . . . .   5
     3.2.  ECDSA . . . . . . . . . . . . . . . . . . . . . . . . . .   6
     3.3.  EdDSA . . . . . . . . . . . . . . . . . . . . . . . . . .   7
   4.  Key Management Algorithms . . . . . . . . . . . . . . . . . .   8
     4.1.  Key Agreement Algorithms  . . . . . . . . . . . . . . . .   8
       4.1.1.  Diffie-Hellman  . . . . . . . . . . . . . . . . . . .   8
       4.1.2.  ECDH  . . . . . . . . . . . . . . . . . . . . . . . .   9
     4.2.  Key Transport Algorithms  . . . . . . . . . . . . . . . .  10
       4.2.1.  RSA . . . . . . . . . . . . . . . . . . . . . . . . .  10
     4.3.  Symmetric Key-Encryption Algorithms . . . . . . . . . . .  11
       4.3.1.  AES Key Wrap  . . . . . . . . . . . . . . . . . . . .  11
     4.4.  Key Derivation Algorithms . . . . . . . . . . . . . . . .  12
       4.4.1.  PBKDF2  . . . . . . . . . . . . . . . . . . . . . . .  12
   5.  Content Encryption Algorithms . . . . . . . . . . . . . . . .  13
     5.1.  AES-CBC . . . . . . . . . . . . . . . . . . . . . . . . .  13
   6.  Message Authentication Code Algorithms  . . . . . . . . . . .  14
     6.1.  Password-Based MAC  . . . . . . . . . . . . . . . . . . .  14
       6.1.1.  PasswordBasedMac  . . . . . . . . . . . . . . . . . .  14
       6.1.2.  PBMAC1  . . . . . . . . . . . . . . . . . . . . . . .  15
     6.2.  Symmetric Key-Based MAC . . . . . . . . . . . . . . . . .  15
       6.2.1.  SHA2-Based HMAC . . . . . . . . . . . . . . . . . . .  15
       6.2.2.  AES-GMAC  . . . . . . . . . . . . . . . . . . . . . .  16
       6.2.3.  SHAKE-Based KMAC  . . . . . . . . . . . . . . . . . .  16
   7.  Algorithm Use Profiles  . . . . . . . . . . . . . . . . . . .  17
     7.1.  Algorithm Profile for RFC 4210 PKI Management Message
           Profiles  . . . . . . . . . . . . . . . . . . . . . . . .  20
     7.2.  Algorithm Profile for Lightweight CMP Profile . . . . . .  22
   8.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  23
   9.  Security Considerations . . . . . . . . . . . . . . . . . . .  24
   10. Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  25
   11. Normative References  . . . . . . . . . . . . . . . . . . . .  25



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   12. Informative References  . . . . . . . . . . . . . . . . . . .  29
   Appendix A.  History of Changes . . . . . . . . . . . . . . . . .  29
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  32

1.  Introduction

   RFC 4210 Appendix D.2 [RFC4210] contains a set of algorithms,
   mandatory to be supported by conforming implementations.  These
   algorithms were appropriate at the time CMP was released, but as
   cryptographic algorithms weaken over time, some of them should not be
   used anymore.  In general, new attacks are emerging due to research
   cryptoanalysis or increase in computing power.  New algorithms were
   introduced that are more resistant to today's attacks.

   This document lists current cryptographic algorithms usable with CMP
   to offer an easier way maintaining the list of suitable algorithms
   over time.

1.1.  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.

   In the following sections ASN.1 values and types are used to indicate
   where algorithm identifier and output values are provided.  These
   ASN.1 values and types are defined in CMP [RFC4210], CRMF [RFC4211],
   CMP Updates [I-D.ietf-lamps-cmp-updates], or CMS [RFC5652].

2.  Message Digest Algorithms

   This section provides references to object identifiers and
   conventions to be employed by CMP implementations that support SHA2
   or SHAKE message digest algorithms.

   Digest algorithm identifiers are located in:

   *  hashAlg field of OOBCertHash and CertStatus
   *  owf field of Challenge, PBMParameter, and DHBMParameter
   *  digestAlgorithms field of SignedData
   *  digestAlgorithm field of SignerInfo

   Digest values are located in:

   *  hashVal field of OOBCertHash
   *  certHash field of CertStatus



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   *  witness field of Challenge

   In addition, digest values are input to signature algorithms.

2.1.  SHA2

   The SHA2 algorithm family is defined in FIPS Pub 180-4
   [NIST.FIPS.180-4].

   The message digest algorithms SHA-224, SHA-256, SHA-384, and SHA-512
   are identified by the following OIDs:

      id-sha224 OBJECT IDENTIFIER ::= { joint-iso-itu-t(2) country(16)
         us(840) organization(1) gov(101) csor(3) nistalgorithm(4)
         hashalgs(2) 4 }
      id-sha256 OBJECT IDENTIFIER ::= { joint-iso-itu-t(2) country(16)
         us(840) organization(1) gov(101) csor(3) nistalgorithm(4)
         hashalgs(2) 1 }
      id-sha384 OBJECT IDENTIFIER ::= { joint-iso-itu-t(2) country(16)
         us(840) organization(1) gov(101) csor(3) nistalgorithm(4)
         hashalgs(2) 2 }
      id-sha512 OBJECT IDENTIFIER ::= { joint-iso-itu-t(2) country(16)
         us(840) organization(1) gov(101) csor(3) nistalgorithm(4)
         hashalgs(2) 3 }

   Specific conventions to be considered are specified in RFC 5754
   Section 2 [RFC5754].

2.2.  SHAKE

   The SHA-3 family of hash functions is defined in FIPS Pub 202
   [NIST.FIPS.202] and includes fixed output length variants SHA3-224,
   SHA3-256, SHA3-384, and SHA3-512, as well as extendable-output
   functions (SHAKEs) SHAKE128 and SHAKE256.  Currently, SHAKE128 and
   SHAKE256 are the only members of the SHA3-family which are specified
   for use in X.509 certificates [RFC8692] and CMS [RFC8702] as one-way
   hash function for use with RSASSA-PSS and ECDSA.

   SHAKE is an extendable-output function and FIPS Pub 202
   [NIST.FIPS.202] prohibits using SHAKE as general-purpose hash
   function.  When SHAKE is used in CMP as a message digest algorithm,
   the output length MUST be 256 bits for SHAKE128 and 512 bits for
   SHAKE256.

   The message digest algorithms SHAKE128 and SHAKE256 are identified by
   the following OIDs:





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      id-shake128 OBJECT IDENTIFIER ::= { joint-iso-itu-t(2) country(16)
         us(840) organization(1) gov(101) csor(3) nistAlgorithm(4)
         hashalgs(2) 11 }
      id-shake256 OBJECT IDENTIFIER ::= { joint-iso-itu-t(2) country(16)
         us(840) organization(1) gov(101) csor(3) nistAlgorithm(4)
         hashalgs(2) 12 }

   Specific conventions to be considered are specified in RFC 8702
   Section 3.1 [RFC8702].

3.  Signature Algorithms

   This section provides references to object identifiers and
   conventions to be employed by CMP implementations that support RSA,
   ECDSA, or EdDSA signature algorithms.

   The signature algorithm is referred to as MSG_SIG_ALG in Section 7.2,
   RFC 4210 Appendix D and E [RFC4210], and in the Lightweight CMP
   Profile [I-D.ietf-lamps-lightweight-cmp-profile].

   Signature algorithm identifiers are located in:

   *  protectionAlg field of PKIHeader
   *  algorithmIdentifier field of POPOSigningKey
   *  signatureAlgorithm field of CertificationRequest,
      SignKeyPairTypes, and SignerInfo

   Signature values are located in:

   *  protection field of PKIMessage
   *  signature field of POPOSigningKey
   *  signature field of CertificationRequest and SignerInfo

3.1.  RSA

   The RSA (RSASSA-PSS and PKCS#1 version 1.5) signature algorithm is
   defined in RFC 8017 [RFC8017].

   The algorithm identifier for RSASAA-PSS signatures used with SHA2
   message digest algorithms is identified by the following OID:

      id-RSASSA-PSS OBJECT IDENTIFIER ::= { iso(1) member-body(2)
         us(840) rsadsi(113549) pkcs(1) pkcs-1(1) 10 }

   Specific conventions to be considered are specified in RFC 4056
   [RFC4056].





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   The signature algorithm RSASSA-PSS used with SHAKE message digest
   algorithms are identified by the following OIDs:

      id-RSASSA-PSS-SHAKE128  OBJECT IDENTIFIER  ::=  { iso(1)
         identified-organization(3) dod(6) internet(1) security(5)
         mechanisms(5) pkix(7) algorithms(6) 30 }
      id-RSASSA-PSS-SHAKE256  OBJECT IDENTIFIER  ::=  { iso(1)
         identified-organization(3) dod(6) internet(1) security(5)
         mechanisms(5) pkix(7) algorithms(6) 31 }

   Specific conventions to be considered are specified in RFC 8702
   Section 3.2.1 [RFC8702].

   The signature algorithm PKCS#1 version 1.5 used with SHA2 message
   digest algorithms is identified by the following OIDs:

      sha224WithRSAEncryption OBJECT IDENTIFIER ::= { iso(1)
         member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-1(1) 14 }
      sha256WithRSAEncryption  OBJECT IDENTIFIER  ::=  { iso(1)
         member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-1(1) 11 }
      sha384WithRSAEncryption  OBJECT IDENTIFIER  ::=  { iso(1)
         member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-1(1) 12 }
      sha512WithRSAEncryption  OBJECT IDENTIFIER  ::=  { iso(1)
         member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs-1(1) 13 }

   Specific conventions to be considered are specified in RFC 5754
   Section 3.2 [RFC5754].

3.2.  ECDSA

   The ECDSA signature algorithm is defined in FIPS Pub 186-4
   [NIST.FIPS.186-4].

   The signature algorithm ECDSA used with SHA2 message digest
   algorithms is identified by the following OIDs:

      ecdsa-with-SHA224 OBJECT IDENTIFIER ::= { iso(1) member-body(2)
         us(840) ansi-X9-62(10045) signatures(4) ecdsa-with-SHA2(3) 1 }
      ecdsa-with-SHA256 OBJECT IDENTIFIER ::= { iso(1) member-body(2)
         us(840) ansi-X9-62(10045) signatures(4) ecdsa-with-SHA2(3) 2 }
      ecdsa-with-SHA384 OBJECT IDENTIFIER ::= { iso(1) member-body(2)
         us(840) ansi-X9-62(10045) signatures(4) ecdsa-with-SHA2(3) 3 }
      ecdsa-with-SHA512 OBJECT IDENTIFIER ::= { iso(1) member-body(2)
         us(840) ansi-X9-62(10045) signatures(4) ecdsa-with-SHA2(3) 4 }

   As specified in RFC 5480 [RFC5480] the NIST-recommended SECP curves
   are identified by the following OIDs:




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      secp192r1 OBJECT IDENTIFIER ::= { iso(1) member-body(2)
          us(840) ansi-X9-62(10045) curves(3) prime(1) 1 }
      secp224r1 OBJECT IDENTIFIER ::= { iso(1)
          identified-organization(3) certicom(132) curve(0) 33 }
      secp256r1 OBJECT IDENTIFIER ::= { iso(1) member-body(2)
          us(840) ansi-X9-62(10045) curves(3) prime(1) 7 }
      secp384r1 OBJECT IDENTIFIER ::= { iso(1)
          identified-organization(3) certicom(132) curve(0) 34 }
      secp521r1 OBJECT IDENTIFIER ::= { iso(1)
          identified-organization(3) certicom(132) curve(0) 35 }

   Specific conventions to be considered are specified in RFC 5754
   Section 3.3 [RFC5754].

   The signature algorithm ECDSA used with SHAKE message digest
   algorithms are identified by the following OIDs:

      id-ecdsa-with-shake128 OBJECT IDENTIFIER  ::=  { iso(1)
         identified-organization(3) dod(6) internet(1) security(5)
         mechanisms(5) pkix(7) algorithms(6) 32 }
      id-ecdsa-with-shake256 OBJECT IDENTIFIER  ::=  { iso(1)
         identified-organization(3) dod(6) internet(1) security(5)
         mechanisms(5) pkix(7) algorithms(6) 33 }

   Specific conventions to be considered are specified in RFC 8702
   Section 3.2.2 [RFC8702].

3.3.  EdDSA

   The EdDSA signature algorithm is defined in RFC 8032 Section 3.3
   [RFC8032] and FIPS Pub 186-5 (Draft) [NIST.FIPS.186-5].

   The signature algorithm Ed25519 that MUST be used with SHA-512
   message digest algorithms is identified by the following OIDs:

      id-Ed25519 OBJECT IDENTIFIER  ::=  { iso(1)
         identified-organization(3) thawte(101) 112 }

   The signature algorithm Ed448 that MUST be used with SHAKE256 message
   digest algorithms is identified by the following OIDs:

      id-Ed448 OBJECT IDENTIFIER  ::=  { iso(1)
         identified-organization(3) thawte(101) 113 }

   Specific conventions to be considered are specified in RFC 8419
   [RFC8419].





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   Note: The hash algorithm used to calculate the certHash in certConf
   messages MUST be SHA512 if the certificate to be confirmed has been
   signed using Ed25519 and SHAKE256 with d=512 if signed using Ed448.

4.  Key Management Algorithms

   CMP utilizes the following general key management techniques: key
   agreement, key transport, and passwords.

   CRMF [RFC4211] and CMP Updates [I-D.ietf-lamps-cmp-updates] promotes
   the use of CMS [RFC5652] EnvelopedData by deprecating the use of
   EncryptedValue.

4.1.  Key Agreement Algorithms

   The key agreement algorithm is referred to as PROT_ENC_ALG in
   RFC 4210 Appendix D and E [RFC4210] and as KM_KA_ALG in the
   Lightweight CMP Profile [I-D.ietf-lamps-lightweight-cmp-profile], as
   well as in Section 7.

   Key agreement algorithms are only used in CMP when using CMS
   [RFC5652] EnvelopedData together with the key agreement key
   management technique.  When a key agreement algorithm is used, a key-
   encryption algorithm (Section 4.3) is needed next to the content-
   encryption algorithm (Section 5).

   Key agreement algorithm identifiers are located in:

   *  keyEncryptionAlgorithm field of KeyAgreeRecipientInfo

   Key wrap algorithm identifiers are located in:

   *  KeyWrapAlgorithm parameters within keyEncryptionAlgorithm field of
      KeyAgreeRecipientInfo

   Wrapped content-encryption keys are located in:

   *  encryptedKey field of RecipientEncryptedKeys

4.1.1.  Diffie-Hellman

   Diffie-Hellman key agreement is defined in RFC 2631 [RFC2631] and
   SHALL be used in the ephemeral-static as specified in RFC 3370
   [RFC3370].  Static-static variants SHALL NOT be used.

   The Diffie-Hellman key agreement algorithm is identified by the
   following OID:




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      id-alg-ESDH OBJECT IDENTIFIER ::= { iso(1) member-body(2)
         us(840) rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) alg(3) 5 }

   Specific conventions to be considered are specified in RFC 3370
   Section 4.1 [RFC3370].

4.1.2.  ECDH

   Elliptic Curve Diffie-Hellman (ECDH) key agreement is defined in
   RFC 5753 [RFC5753] and SHALL be used in the ephemeral-static variant
   as specified in RFC 5753 [RFC5753] or the 1-Pass ECMQV variant as
   specified in RFC 5753 [RFC5753].  Static-static variants SHALL NOT be
   used.

   The ECDH key agreement algorithm used together with NIST-recommended
   SECP curves are identified by the following OIDs:

      dhSinglePass-stdDH-sha224kdf-scheme OBJECT IDENTIFIER ::= { iso(1)
          identified-organization(3) certicom(132) schemes(1) 11(11) 0 }
      dhSinglePass-stdDH-sha256kdf-scheme OBJECT IDENTIFIER ::= { iso(1)
          identified-organization(3) certicom(132) schemes(1) 11(11) 1 }
      dhSinglePass-stdDH-sha384kdf-scheme OBJECT IDENTIFIER ::= { iso(1)
          identified-organization(3) certicom(132) schemes(1) 11(11) 2 }
      dhSinglePass-stdDH-sha512kdf-scheme OBJECT IDENTIFIER ::= { iso(1)
          identified-organization(3) certicom(132) schemes(1) 11(11) 3 }
      dhSinglePass-cofactorDH-sha224kdf-scheme OBJECT IDENTIFIER ::= {
          iso(1) identified-organization(3) certicom(132) schemes(1)
          14(14) 0 }
      dhSinglePass-cofactorDH-sha256kdf-scheme OBJECT IDENTIFIER ::= {
          iso(1) identified-organization(3) certicom(132) schemes(1)
          14(14) 1 }
      dhSinglePass-cofactorDH-sha384kdf-scheme OBJECT IDENTIFIER ::= {
          iso(1) identified-organization(3) certicom(132) schemes(1)
          14(14) 2 }
      dhSinglePass-cofactorDH-sha512kdf-scheme OBJECT IDENTIFIER ::= {
          iso(1) identified-organization(3) certicom(132) schemes(1)
          14(14) 3 }
      mqvSinglePass-sha224kdf-scheme OBJECT IDENTIFIER ::= { iso(1)
          identified-organization(3) certicom(132) schemes(1) 15(15) 0 }
      mqvSinglePass-sha256kdf-scheme OBJECT IDENTIFIER ::= { iso(1)
          identified-organization(3) certicom(132) schemes(1) 15(15) 1 }
      mqvSinglePass-sha384kdf-scheme OBJECT IDENTIFIER ::= { iso(1)
          identified-organization(3) certicom(132) schemes(1) 15(15) 2 }
      mqvSinglePass-sha512kdf-scheme OBJECT IDENTIFIER ::= { iso(1)
          identified-organization(3) certicom(132) schemes(1) 15(15) 3 }

   As specified in RFC 5480 [RFC5480] the NIST-recommended SECP curves
   are identified by the following OIDs:



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      secp192r1 OBJECT IDENTIFIER ::= { iso(1) member-body(2)
          us(840) ansi-X9-62(10045) curves(3) prime(1) 1 }
      secp224r1 OBJECT IDENTIFIER ::= { iso(1)
          identified-organization(3) certicom(132) curve(0) 33 }
      secp256r1 OBJECT IDENTIFIER ::= { iso(1) member-body(2)
          us(840) ansi-X9-62(10045) curves(3) prime(1) 7 }
      secp384r1 OBJECT IDENTIFIER ::= { iso(1)
          identified-organization(3) certicom(132) curve(0) 34 }
      secp521r1 OBJECT IDENTIFIER ::= { iso(1)
          identified-organization(3) certicom(132) curve(0) 35 }

   Specific conventions to be considered are specified in RFC 5753
   [RFC5753].

   The ECDH key agreement algorithm used together with curve25519 or
   curve448 are identified by the following OIDs:

      id-X25519 OBJECT IDENTIFIER ::= { iso(1)
         identified-organization(3) thawte(101) 110 }
      id-X448 OBJECT IDENTIFIER ::= { iso(1)
         identified-organization(3) thawte(101) 111 }

   Specific conventions to be considered are specified in RFC 8418
   [RFC8418].

4.2.  Key Transport Algorithms

   The key transport algorithm is also referred to as PROT_ENC_ALG in
   RFC 4210 Appendix D and E [RFC4210] and as KM_KL_ALG in the
   Lightweight CMP Profile [I-D.ietf-lamps-lightweight-cmp-profile], as
   well as in Section 7.

   Key transport algorithms are only used in CMP when using CMS
   [RFC5652] EnvelopedData together with the key transport key
   management technique.

   Key transport algorithm identifiers are located in:

   *  keyEncryptionAlgorithm field of KeyTransRecipientInfo

   Key transport encrypted content-encryption keys are located in:

   *  encryptedKey field of KeyTransRecipientInfo

4.2.1.  RSA

   The RSA key transport algorithm is the RSA encryption scheme defined
   in RFC 8017 [RFC8017].



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   The algorithm identifier for RSA (PKCS #1 v1.5) is:

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

   The algorithm identifier for RSAES-OAEP is:

      id-RSAES-OAEP  OBJECT IDENTIFIER  ::=  { iso(1) member-body(2)
         us(840) rsadsi(113549) pkcs(1) pkcs-1(1) 7 }

   Further conventions to be considered for PKCS #1 v1.5 are specified
   in RFC 3370 Section 4.2.1 [RFC3370] and for RSAES-OAEP in RFC 3560
   [RFC3560].

4.3.  Symmetric Key-Encryption Algorithms

   The symmetric key-encryption algorithm is also referred to as
   KM_KW_ALG in Section 7.2 and in the Lightweight CMP Profile
   [I-D.ietf-lamps-lightweight-cmp-profile].

   As symmetric key-encryption key management technique is not used by
   CMP, the symmetric key-encryption algorithm is only needed when using
   the key agreement or password-based key management technique with CMS
   [RFC5652] EnvelopedData.

   Key wrap algorithm identifiers are located in:

   *  parameters field of the KeyEncryptionAlgorithmIdentifier of
      KeyAgreeRecipientInfo and PasswordRecipientInfo

   Wrapped content-encryption keys are located in:

   *  encryptedKey field of RecipientEncryptedKeys (for key agreement)
      and PasswordRecipientInfo (for password-based key management)

4.3.1.  AES Key Wrap

   The AES encryption algorithm is defined in FIPS Pub 197
   [NIST.FIPS.197] and the key wrapping is defined in RFC 3394
   [RFC3394].

   AES key encryption has the algorithm identifier:









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      id-aes128-wrap OBJECT IDENTIFIER ::= { joint-iso-itu-t(2)
         country(16) us(840) organization(1) gov(101) csor(3)
         nistAlgorithm(4) aes(1) 5 }
      id-aes192-wrap OBJECT IDENTIFIER ::= { joint-iso-itu-t(2)
         country(16) us(840) organization(1) gov(101) csor(3)
         nistAlgorithm(4) aes(1) 25 }
      id-aes256-wrap OBJECT IDENTIFIER ::= { joint-iso-itu-t(2)
         country(16) us(840) organization(1) gov(101) csor(3)
         nistAlgorithm(4) aes(1) 45 }

   The underlying encryption functions for the key wrap and content-
   encryption algorithms (as specified in Section 5) and the key sizes
   for the two algorithms MUST be the same (e.g., AES-128 key wrap
   algorithm with AES-128 content-encryption algorithm), see also
   RFC 8551 [RFC8551].

   Further conventions to be considered for AES key wrap are specified
   in RFC 3394 Section 2.2 [RFC3394] and RFC 3565 Section 2.3.2
   [RFC3565].

4.4.  Key Derivation Algorithms

   The key derivation algorithm is also referred to as KM_KD_ALG in
   Section 7.2 and in the Lightweight CMP Profile
   [I-D.ietf-lamps-lightweight-cmp-profile].

   Key derivation algorithms are only used in CMP when using CMS
   [RFC5652] EnvelopedData together with password-based key management
   technique.

   Key derivation algorithm identifiers are located in:

   *  keyDerivationAlgorithm field of PasswordRecipientInfo

   When using the password-based key management technique with
   EnvelopedData as specified in CMP Updates together with message
   authentication code (MAC)-based PKIProtection, the salt for the
   password-based MAC and KDF must be chosen independently to ensure
   usage of independent symmetric keys.

4.4.1.  PBKDF2

   The password-based key derivation function 2 (PBKDF2) is defined in
   RFC 8018 [RFC8018].

   Password-based key derivation function 2 has the algorithm
   identifier:




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      id-PBKDF2 OBJECT IDENTIFIER ::= { iso(1) member-body(2) us(840)
         rsadsi(113549) pkcs(1) pkcs-5(5) 12 }

   Further conventions to be considered for PBKDF2 are specified in
   RFC 3370 Section 4.4.1 [RFC3370] and RFC 8018 Section 5.2 [RFC8018].

5.  Content Encryption Algorithms

   The content encryption algorithm is also referred to as PROT_SYM_ALG
   in Section 7, RFC 4210 Appendix D and E [RFC4210], and the
   Lightweight CMP Profile [I-D.ietf-lamps-lightweight-cmp-profile].

   Content encryption algorithms are only used in CMP when using CMS
   [RFC5652] EnvelopedData to transport a signed private key package in
   case of central key generation or key archiving, a certificate to
   facilitate implicit proof-of-possession, or a revocation passphrase
   in encrypted form.

   Content encryption algorithm identifiers are located in:

   *  contentEncryptionAlgorithm field of EncryptedContentInfo

   Encrypted content is located in:

   *  encryptedContent field of EncryptedContentInfo

5.1.  AES-CBC

   The AES encryption algorithm is defined in FIPS Pub 197
   [NIST.FIPS.197].

   AES-CBC content encryption has the algorithm identifier:

      id-aes128-CBC OBJECT IDENTIFIER ::= { joint-iso-itu-t(2)
         country(16) us(840) organization(1) gov(101) csor(3)
         nistAlgorithm(4) aes(1) 2 }
      id-aes192-CBC OBJECT IDENTIFIER ::= { joint-iso-itu-t(2)
         country(16) us(840) organization(1) gov(101) csor(3)
         nistAlgorithm(4) aes(1)22 }
      id-aes256-CBC OBJECT IDENTIFIER ::= { joint-iso-itu-t(2)
         country(16) us(840) organization(1) gov(101) csor(3)
         nistAlgorithm(4) aes(1)42 }

   Specific conventions to be considered for AES-CBC content encryption
   are specified in RFC 3565 [RFC3565].






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6.  Message Authentication Code Algorithms

   The message authentication code (MAC) is either used for shared
   secret-based CMP message protection or together with the password-
   based key derivation function (PBKDF2).

   The message authentication code algorithm is also referred to as
   MSG_MAC_ALG in Section 7, RFC 4210 Appendix D and E [RFC4210], and
   the Lightweight CMP Profile [I-D.ietf-lamps-lightweight-cmp-profile].

6.1.  Password-Based MAC

   Password-based message authentication code (MAC) algorithms combine
   the derivation of a symmetric key from a password or other shared
   secret information and a symmetric key-based MAC function as
   specified in Section 6.2 using this derived key.

   Message authentication code algorithm identifiers are located in:

   *  protectionAlg field of PKIHeader

   Message authentication code values are located in:

   *  PKIProtection field of PKIMessage

6.1.1.  PasswordBasedMac

   The PasswordBasedMac algorithm is defined in RFC 4210 Section 5.1.3.1
   [RFC4210], RFC 4211 Section 4.4 [RFC4211], and Algorithm Requirements
   Update to the Internet X.509 Public Key Infrastructure Certificate
   Request Message Format (CRMF) [RFC9045].

   The PasswordBasedMac algorithm is identified by the following OID:

      id-PasswordBasedMac OBJECT IDENTIFIER ::= { iso(1) member-body(2)
         us(840) nt(113533) nsn(7) algorithms(66) 13 }

   Further conventions to be considered for password-based MAC are
   specified in RFC 4210 Section 5.1.3.1 [RFC4210], RFC 4211 Section 4.4
   [RFC4211], and Algorithm Requirements Update to the Internet X.509
   Public Key Infrastructure Certificate Request Message Format (CRMF)
   [RFC9045].









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6.1.2.  PBMAC1

   The Password-Based Message Authentication Code 1 (PBMAC1) is defined
   in RFC 8018 [RFC8018].  PBMAC1 combines a password-based key
   derivation function like PBKDF2 (Section 4.4.1) with an underlying
   symmetric key-based message authentication scheme.

   PBMAC1 has the following OID:

      id-PBMAC1 OBJECT IDENTIFIER ::= { iso(1) member-body(2) us(840)
         rsadsi(113549) pkcs(1) pkcs-5(5) 14 }

   Specific conventions to be considered for PBMAC1 are specified in
   RFC 8018 Section 7.1 and A.5 [RFC8018].

6.2.  Symmetric Key-Based MAC

   Symmetric key-based message authentication code (MAC) algorithms are
   used for deriving the symmetric encryption key when using PBKDF2 as
   described in Section 4.4.1 as well as with Password-based MAC as
   described in Section 6.1.

   Message authentication code algorithm identifiers are located in:

   *  protectionAlg field of PKIHeader
   *  messageAuthScheme field of PBMAC1
   *  mac field of PBMParameter
   *  prf field of PBKDF2-params

   Message authentication code values are located in:

   *  PKIProtection field of PKIMessage

6.2.1.  SHA2-Based HMAC

   The HMAC algorithm is defined in RFC 2104 [RFC2104] and
   FIPS Pub 198-1 [NIST.FIPS.198-1].

   The HMAC algorithm used with SHA2 message digest algorithms is
   identified by the following OIDs:











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      id-hmacWithSHA224 OBJECT IDENTIFIER ::= { iso(1) member-body(2)
         us(840) rsadsi(113549) digestAlgorithm(2) 8 }
      id-hmacWithSHA256 OBJECT IDENTIFIER ::= { iso(1) member-body(2)
         us(840) rsadsi(113549) digestAlgorithm(2) 9 }
      id-hmacWithSHA384 OBJECT IDENTIFIER ::= { iso(1) member-body(2)
         us(840) rsadsi(113549) digestAlgorithm(2) 10 }
      id-hmacWithSHA512 OBJECT IDENTIFIER ::= { iso(1) member-body(2)
         us(840) rsadsi(113549) digestAlgorithm(2) 11 }

   Specific conventions to be considered for SHA2-based HMAC are
   specified in RFC 4231 Section 3.1 [RFC4231].

6.2.2.  AES-GMAC

   The AES-GMAC algorithm is defined in FIPS Pub 197 [NIST.FIPS.197] and
   NIST SP 800-38d [NIST.SP.800-38d].

   Note: AES-GMAC MUST NOT be used twice with the same parameter set,
   especially the same nonce.  Therefore, it MUST NOT be used together
   with PBKDF2.  When using it with PBMAC1 it MUST be ensured that AES-
   GMAC is only used as message authentication scheme and not for the
   key derivation function PBKDF2.

   The AES-GMAC algorithm is identified by the following OIDs:

      id-aes128-GMAC OBJECT IDENTIFIER ::= { joint-iso-itu-t(2)
         country(16) us(840) organization(1) gov(101) csor(3)
         nistAlgorithm(4) aes(1) 9 }
      id-aes192-GMAC OBJECT IDENTIFIER ::= { joint-iso-itu-t(2)
         country(16) us(840) organization(1) gov(101) csor(3)
         nistAlgorithm(4) aes(1) 29 }
      id-aes256-GMAC OBJECT IDENTIFIER ::= { joint-iso-itu-t(2)
         country(16) us(840) organization(1) gov(101) csor(3)
         nistAlgorithm(4) aes(1) 49 }

   Specific conventions to be considered for AES-GMAC are specified in
   RFC 9044 [RFC9044].

6.2.3.  SHAKE-Based KMAC

   The KMAC algorithm is defined in RFC 8702 [RFC8702] and
   FIPS SP 800-185 [NIST.SP.800-185].

   The SHAKE-based KMAC algorithm is identified by the following OIDs:







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      id-KmacWithSHAKE128 OBJECT IDENTIFIER ::= { joint-iso-itu-t(2)
         country(16) us(840) organization(1) gov(101) csor(3)
         nistAlgorithm(4) 2 19 }
      id-KmacWithSHAKE256 OBJECT IDENTIFIER ::= { joint-iso-itu-t(2)
         country(16) us(840) organization(1) gov(101) csor(3)
         nistAlgorithm(4) 2 20 }

   Specific conventions to be considered for KMAC with SHAKE are
   specified in RFC 8702 Section 3.4 [RFC8702].

7.  Algorithm Use Profiles

   This section provides profiles of algorithms and respective
   conventions for different application use cases.

   Recommendations like NIST SP 800-57 Recommendation for Key Management
   Table 2 [NIST.SP.800-57pt1r5] and ECRYPT Algorithms, Key Size and
   Protocols Report (2018) Section 4.6 [ECRYPT.CSA.D5.4] provide general
   information on current cryptographic algorithms.

   The overall cryptographic strength of a CMP deployment will depend on
   several factors, including:

   *  Capabilities of the end entity: What kind of algorithms does the
      end entity support.  The cryptographic strength of the system
      SHOULD be at least as strong as the algorithms and keys used for
      the certificate being managed.

   *  Algorithm profile: The overall strength of the profile will be the
      strength of the weakest algorithm it contains.

   *  Message protection: The overall strength of the CMC message
      protection

      -  MAC-based protection: The entropy of the shared secret
         information or password when MAC-based message protection is
         used (MSG_MAC_ALG).

      -  Signature-based protection: The strength of the key pair and
         signature algorithm when signature-based protection is used
         (MSG_SIG_ALG).

      -  Protection of centrally generated keys: The strength of the
         algorithms used for the key management technique (Section 7.2:
         PROT_ENC_ALG or Section 7.1: KM_KA_ALG, KM_KT_ALG, KM_KD_ALG)
         and the encryption of the content-encryption key and private
         key (Section 7.2: SYM_PENC_ALG, PROT_SYM_ALG or Section 7.1:
         KM_KW_ALG, PROT_SYM_ALG).



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   The following table shows the algorithms listed in this document
   sorted by their bits of security.  If an implementation intends to
   enroll and manage certificate for keys of a specific security, it
   SHALL implement and use algorithms of at least that strength for the
   respective PKI management operation.  If one row does not provide a
   suitable algorithm, the implementer MUST choose one offering more
   bits of security.

   +=======+==========+================+==================+============+
   | Bits  | RSA or   | Elliptic       | Hash Function or | Symmetric  |
   | of    | DH       | Curve          | XOF with         | Encryption |
   | Secu- |          |                | Specified Output |            |
   | rity  |          |                | Length (d)       |            |
   +=======+==========+================+==================+============+
   | 112   | RSA2048, | ECDSA/ECDH     | SHA224           |            |
   |       | DH(2048) | (secp224r1)    |                  |            |
   +-------+----------+----------------+------------------+------------+
   | 128   | RSA3072, | ECDSA/ECDH     | SHA256,          | AES-128    |
   |       | DH(3072) | (secp256r1),   | SHAKE128(d=256)  |            |
   |       |          | Ed25519/       |                  |            |
   |       |          | X25519         |                  |            |
   |       |          | (Curve25519)   |                  |            |
   +-------+----------+----------------+------------------+------------+
   | 192   |          | ECDSA/ECDH     | SHA384           | AES-192    |
   |       |          | (secp384r1)    |                  |            |
   +-------+----------+----------------+------------------+------------+
   | 224   |          | Ed448/X448     |                  |            |
   |       |          | (Curve448)     |                  |            |
   +-------+----------+----------------+------------------+------------+
   | 256   |          | ECDSA/ECDH     | SHA512,          | AES-256    |
   |       |          | (secp521r1)    | SHAKE256(d=512)  |            |
   +-------+----------+----------------+------------------+------------+

     Table 1: Cryptographic Algorithms Sorted by their Bits of Security

   The following table shows the cryptographic algorithms sorted by
   their usage in CMP and with more details.

   +========+==========+===============+===============+===============+
   |Bits of |Key Types |CMP Protection |Key Management | Key-Wrap and  |
   |Security|to Be     |               |Technique      | Symmetric     |
   |        |Certified |               |               | Encryption    |
   +========+==========+===============+===============+===============+
   |        |          |MSG_SIG_ALG,   |PROT_ENC_ALG or| PROT_SYM_ALG, |
   |        |          |MSG_MAC_ALG    |KM_KA_ALG,     | SYM_PENC_ALG  |
   |        |          |               |KM_KT_ALG,     | or            |
   |        |          |               |KM_KD_ALG      | KM_KW_ALG     |
   +--------+----------+---------------+---------------+---------------+



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   |112     |RSA2048,  |RSASSA-PSS     |DH(2048),      |               |
   |        |secp224r1 |(2048, SHA224  |RSAES-OAEP     |               |
   |        |          |or SHAKE128    |(2048, SHA224),|               |
   |        |          |(d=256)),      |RSAEncryption  |               |
   |        |          |RSAEncryption  |(2048, SHA224),|               |
   |        |          |(2048, SHA224),|ECDH           |               |
   |        |          |ECDSA          |(secp224r1,    |               |
   |        |          |(secp224r1,    |SHA224),       |               |
   |        |          |SHA224 or      |PBKDF2 (HMAC-  |               |
   |        |          |SHAKE128       |SHA224)        |               |
   |        |          |(d=256)),      |               |               |
   |        |          |PBMAC1 (HMAC-  |               |               |
   |        |          |SHA224)        |               |               |
   +--------+----------+---------------+---------------+---------------+
   |128     |RSA3072,  |RSASSA-PSS     |DH(3072),      | AES-128       |
   |        |secp256r1,|(3072, SHA256  |RSAES-OAEP     |               |
   |        |Curve25519|or SHAKE128    |(3072, SHA256),|               |
   |        |          |(d=256)),      |RSAEncryption  |               |
   |        |          |RSAEncryption  |(3072, SHA256),|               |
   |        |          |(3072, SHA256),|ECDH           |               |
   |        |          |ECDSA          |(secp256r1,    |               |
   |        |          |(secp256r1,    |SHA256),       |               |
   |        |          |SHA256 or      |X25519,        |               |
   |        |          |SHAKE128       |PBKDF2 (HMAC-  |               |
   |        |          |(d=256)),      |SHA256)        |               |
   |        |          |Ed25519        |               |               |
   |        |          |(SHA512),      |               |               |
   |        |          |PBMAC1 (HMAC-  |               |               |
   |        |          |SHA256)        |               |               |
   +--------+----------+---------------+---------------+---------------+
   |192     |secp384r1 |ECDSA          |ECDH           | AES-192       |
   |        |          |(secp384r1,    |(secp384r1,    |               |
   |        |          |SHA384),       |SHA384),       |               |
   |        |          |PBMAC1 (HMAC-  |PBKDF2 (HMAC-  |               |
   |        |          |SHA384)        |SHA384)        |               |
   +--------+----------+---------------+---------------+---------------+
   |224     |Curve448  |Ed448          |X448           |               |
   |        |          |(SHAKE256)     |               |               |
   +--------+----------+---------------+---------------+---------------+
   |256     |secp521r1 |ECDSA          |ECDH           | AES-256       |
   |        |          |(secp521r1,    |(secp521r1,    |               |
   |        |          |SHA512 or      |SHA512),       |               |
   |        |          |SHAKE256       |PBKDF2 (HMAC-  |               |
   |        |          |(d=512)),      |SHA512)        |               |
   |        |          |PBMAC1 (HMAC-  |               |               |
   |        |          |SHA512)        |               |               |
   +--------+----------+---------------+---------------+---------------+




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         Table 2: Cryptographic Algorithms Sorted by their Bits of
                         Security and Usage by CMP

   To avoid consuming too many computational resources it is recommended
   to choose a set of algorithms offering roughly the same level of
   security.  Below are provided several algorithm profiles which are
   balanced, assuming the implementer chooses MAC secrets and/or
   certificate profiles of at least equivalent strength.

7.1.  Algorithm Profile for RFC 4210 PKI Management Message Profiles

   The following table updates the definitions of algorithms used within
   PKI Management Message Profiles as defined in CMP Appendix D.2
   [RFC4210].

   The columns in the table are:

   Name: An identifier used for message profiles

   Use: Description of where and for what the algorithm is used

   Mandatory: Algorithms which MUST be supported by conforming
   implementations

   Optional: Algorithms which are OPTIONAL to support

   Deprecated: Algorithms from RFC 4210 [RFC4210] which SHOULD NOT be
   used any more























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   +============+==============+======+===================+============+
   |Name        |Use           |Manda-| Optional          |Deprecated  |
   |            |              |tory  |                   |            |
   +============+==============+======+===================+============+
   |MSG_SIG_ALG |protection of |RSA   | ECDSA, EdDSA      |DSA,        |
   |            |PKI messages  |      |                   |combinations|
   |            |using         |      |                   |with MD5 and|
   |            |signature     |      |                   |SHA-1       |
   +------------+--------------+------+-------------------+------------+
   |MSG_MAC_ALG |protection of |PBMAC1| PasswordBasedMac, |X9.9        |
   |            |PKI messages  |      | HMAC, KMAC        |            |
   |            |using MACing  |      |                   |            |
   +------------+--------------+------+-------------------+------------+
   |SYM_PENC_ALG|symmetric     |AES-  |                   |3-DES(3-key-|
   |            |encryption of |wrap  |                   |EDE, CBC    |
   |            |an end        |      |                   |Mode), RC5, |
   |            |entity's      |      |                   |CAST-128    |
   |            |private key   |      |                   |            |
   |            |where         |      |                   |            |
   |            |symmetric key |      |                   |            |
   |            |is distributed|      |                   |            |
   |            |out-of-band   |      |                   |            |
   +------------+--------------+------+-------------------+------------+
   |PROT_ENC_ALG|asymmetric    |DH    | ECDH, RSA         |            |
   |            |algorithm used|      |                   |            |
   |            |for encryption|      |                   |            |
   |            |of (symmetric |      |                   |            |
   |            |keys for      |      |                   |            |
   |            |encryption of)|      |                   |            |
   |            |private keys  |      |                   |            |
   |            |transported in|      |                   |            |
   |            |PKIMessages   |      |                   |            |
   +------------+--------------+------+-------------------+------------+
   |PROT_SYM_ALG|symmetric     |AES-  |                   |3-DES(3-key-|
   |            |encryption    |CBC   |                   |EDE, CBC    |
   |            |algorithm used|      |                   |Mode), RC5, |
   |            |for encryption|      |                   |CAST-128    |
   |            |of private key|      |                   |            |
   |            |bits (a key of|      |                   |            |
   |            |this type is  |      |                   |            |
   |            |encrypted     |      |                   |            |
   |            |using         |      |                   |            |
   |            |PROT_ENC_ALG) |      |                   |            |
   +------------+--------------+------+-------------------+------------+

           Table 3: Algorithms Used Within RFC 4210 Appendix D.2

   Mandatory Algorithm Identifiers and Specifications:



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   RSA: sha256WithRSAEncryption with 2048 bit, see Section 3.1

   PasswordBasedMac: id-PasswordBasedMac, see Section 6.1 (with id-
   sha256 as the owf parameter, see Section 2.1 and id-hmacWithSHA256 as
   the mac parameter, see Section 6.2.1)

   PBMAC1: id-PBMAC1, see Section 6.1.2 (with id-PBKDF2 as the key
   derivation function, see Section 4.4.1 and id-hmacWithSHA256 as
   message authentication scheme, see Section 6.2.1).  It is RECOMMENDED
   to prefer the usage of PBMAC1 instead of PasswordBasedMac.

   DH: id-alg-ESDH, see Section 4.1.1

   AES-wrap: id-aes128-wrap, see Section 4.3.1

   AES-CBC: id-aes128-CBC, see Section 5.1

7.2.  Algorithm Profile for Lightweight CMP Profile

   The following table contains definitions of algorithms which MAY be
   supported by implementations of the Lightweight CMP Profile
   [I-D.ietf-lamps-lightweight-cmp-profile].

   As the set of algorithms to be used for implementations of the
   Lightweight CMP Profile heavily depends on the PKI management
   operations implemented, the certificates used for messages
   protection, and the certificates to be managed, this document will
   not specify a specific set that is mandatory to support for
   conforming implementations.

   The columns in the table are:

   Name: An identifier used for message profiles

   Use: Description of where and for what the algorithm is used

   Examples: Lists the algorithms as described in this document.  The
   list of algorithms depends on the set of PKI management operations to
   be implemented.

   Note: It is RECOMMENDED to prefer the usage of PBMAC1 instead of
   PasswordBasedMac.









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   +==============+================================+==================+
   | Name         | Use                            | Examples         |
   +==============+================================+==================+
   | MSG_SIG_ALG  | protection of PKI messages     | RSA, ECDSA,      |
   |              | using signature and for        | EdDSA            |
   |              | SignedData, e.g., a private    |                  |
   |              | key transported in PKIMessages |                  |
   +--------------+--------------------------------+------------------+
   | MSG_MAC_ALG  | protection of PKI messages     | PasswordBasedMac |
   |              | using MACing                   | (see Section 9), |
   |              |                                | PBMAC1, HMAC,    |
   |              |                                | KMAC             |
   +--------------+--------------------------------+------------------+
   | KM_KA_ALG    | asymmetric key agreement       | DH, ECDH         |
   |              | algorithm used for agreement   |                  |
   |              | of a symmetric key for use     |                  |
   |              | with KM_KW_ALG                 |                  |
   +--------------+--------------------------------+------------------+
   | KM_KT_ALG    | asymmetric key encryption      | RSA              |
   |              | algorithm used for transport   |                  |
   |              | of a symmetric key for         |                  |
   |              | PROT_SYM_ALG                   |                  |
   +--------------+--------------------------------+------------------+
   | KM_KD_ALG    | symmetric key derivation       | PBKDF2           |
   |              | algorithm used for derivation  |                  |
   |              | of a symmetric key for use     |                  |
   |              | with KM_KW_ALG                 |                  |
   +--------------+--------------------------------+------------------+
   | KM_KW_ALG    | algorithm to wrap a symmetric  | AES-wrap         |
   |              | key for PROT_SYM_ALG           |                  |
   +--------------+--------------------------------+------------------+
   | PROT_SYM_ALG | symmetric content encryption   | AES-CBC          |
   |              | algorithm used for encryption  |                  |
   |              | of EnvelopedData, e.g., a      |                  |
   |              | private key transported in     |                  |
   |              | PKIMessages                    |                  |
   +--------------+--------------------------------+------------------+

         Table 4: Algorithms Used Within Lightweight CMP Profile

8.  IANA Considerations

   This document does not request changes to the IANA registry.








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9.  Security Considerations

   This document lists many cryptographic algorithms usable with CMP to
   offer implementer a more up-to-date choice.  Finally, the algorithms
   to be supported also heavily depend on the certificates and PKI
   management operations utilized in the target environment.  The
   algorithm with the lowest security strength and the entropy of shared
   secret information define the security of the overall solution, see
   Section 7.

   When using MAC-based message protection the use of PBMAC1 is
   preferable to that of PasswordBasedMac.  First, PBMAC1 is a well-
   known scrutinized algorithm, which is not true for PasswordBasedMac.
   Second, the PasswordBasedMac algorithm as specified in RFC 4211
   Section 4.4 [RFC4211] is essentially PBKDF1 (as defined in RFC 8018
   Section 5.1 [RFC8018]) with an HMAC step at the end.  Here we update
   to use the PBKDF2-HMAC construct defined as PBMAC1 in [RFC8018].
   PBKDF2 is superior to PBKDF1 in an improved internal construct for
   iterated hashing, and in removing PBKDF1's limitation of only being
   able to derive keys up to the size of the underlying hash function.
   Additionally, PBKDF1 is not recommended for new applications as
   stated in Section 5.1 of RFC 8018 [RFC8018] and no longer an approved
   algorithm by most standards bodies, and therefore presents
   difficulties to implementer who are submitting their CMP
   implementations for certification, hence moving to a PBKDF2-based
   mechanism.  This change is in alignment with [RFC9045] which updates
   [RFC4211] to allow the use of PBMAC1 in CRMF.

   AES-GMAC MUST NOT be used as the pseudo random function in PBKDF2;
   the use of AES-GMAC more than once with the same key and the same
   nonce will break the security.

   In Section 7 of this document there is also an update to the
   Appendix D.2 of RFC 4210 [RFC4210] and a set of algorithms that MAY
   be supported when implementing the Lightweight CMP Profile
   [I-D.ietf-lamps-lightweight-cmp-profile].

   It is recognized that there may be older CMP implementations in use
   that conform to the algorithm use profile from Appendix D.2 of
   RFC 4210 [RFC4210].  For example, the use of AES is now mandatory for
   PROT_SYM_ALG but in RFC 4210 [RFC4210] 3-DES was mandatory.
   Therefore, it is expected that many CMP systems may already support
   the recommended algorithms in this specification.  In such systems
   the weakened algorithms should be disabled from further use.  If
   critical systems cannot be immediately updated to conform to the
   recommended algorithm use profile, it is recommended a plan to
   migrate the infrastructure to conforming profiles be adopted as soon
   as possible.



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   Symmetric key-based MAC algorithms as described in Section 6.2 MAY be
   used as MSG_MAC_ALG.  The implementer MUST choose a suitable PRF and
   ensure that the key has sufficient entropy to match the overall
   security level of the algorithm profile.  These considerations are
   outside the scope of the profile.

10.  Acknowledgements

   Thanks to Russ Housley for supporting this draft with submitting
   [RFC9044] and [RFC9045].

   May thanks also to all reviewers like Serge Mister, Mark Ferreira,
   Yuefei Lu, Tomas Gustavsson, Lijun Liao, David von Oheimb and Steffen
   Fries for their input and feedback to this document.  Apologies to
   all not mentioned reviewers and supporters.

11.  Normative References

   [I-D.ietf-lamps-cmp-updates]
              Brockhaus, H., Oheimb, D. V., and J. Gray, "Certificate
              Management Protocol (CMP) Updates", Work in Progress,
              Internet-Draft, draft-ietf-lamps-cmp-updates-20, 31 May
              2022, <https://datatracker.ietf.org/doc/html/draft-ietf-
              lamps-cmp-updates-20>.

   [I-D.ietf-lamps-lightweight-cmp-profile]
              Brockhaus, H., Oheimb, D. V., and S. Fries, "Lightweight
              Certificate Management Protocol (CMP) Profile", Work in
              Progress, Internet-Draft, draft-ietf-lamps-lightweight-
              cmp-profile-12, 13 May 2022,
              <https://datatracker.ietf.org/doc/html/draft-ietf-lamps-
              lightweight-cmp-profile-12>.

   [NIST.FIPS.180-4]
              Dang, Quynh H., "Secure Hash Standard", NIST NIST FIPS
              180-4, DOI 10.6028/NIST.FIPS.180-4, July 2015,
              <https://nvlpubs.nist.gov/nistpubs/FIPS/
              NIST.FIPS.180-4.pdf>.

   [NIST.FIPS.186-4]
              National Institute of Standards and Technology (NIST),
              "Digital Signature Standard (DSS)", NIST NIST FIPS 186-4,
              DOI 10.6028/NIST.FIPS.186-4, July 2013,
              <https://nvlpubs.nist.gov/nistpubs/FIPS/
              NIST.FIPS.186-4.pdf>.






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   [NIST.FIPS.186-5]
              National Institute of Standards and Technology (NIST),
              "FIPS Pub 186-5 (Draft): Digital Signature Standard
              (DSS)", October 2019,
              <https://nvlpubs.nist.gov/nistpubs/FIPS/
              NIST.FIPS.186-5-draft.pdf>.

   [NIST.FIPS.197]
              National Institute of Standards and Technology (NIST),
              "Advanced encryption standard (AES)", NIST NIST FIPS 197,
              DOI 10.6028/NIST.FIPS.197, November 2001,
              <https://nvlpubs.nist.gov/nistpubs/FIPS/
              NIST.FIPS.197.pdf>.

   [NIST.FIPS.198-1]
              National Institute of Standards and Technology (NIST),
              "The Keyed-Hash Message Authentication Code (HMAC)",
              NIST NIST FIPS 198-1, DOI 10.6028/NIST.FIPS.198-1, July
              2008, <https://nvlpubs.nist.gov/nistpubs/FIPS/
              NIST.FIPS.198-1.pdf>.

   [NIST.FIPS.202]
              Dworkin, Morris J., "SHA-3 Standard: Permutation-Based
              Hash and Extendable-Output Functions", NIST NIST FIPS 202,
              DOI 10.6028/NIST.FIPS.202, July 2015,
              <https://nvlpubs.nist.gov/nistpubs/FIPS/
              NIST.FIPS.202.pdf>.

   [NIST.SP.800-185]
              Kelsey, John., Change, Shu-jen., and Ray. Perlner, "SHA-3
              derived functions: cSHAKE, KMAC, TupleHash and
              ParallelHash", NIST NIST SP 800-185,
              DOI 10.6028/NIST.SP.800-185, December 2016,
              <https://nvlpubs.nist.gov/nistpubs/SpecialPublications/
              NIST.SP.800-185.pdf>.

   [NIST.SP.800-38d]
              Dworkin, M J., "Recommendation for block cipher modes of
              operation :GaloisCounter Mode (GCM) and GMAC", NIST NIST
              SP 800-38d, DOI 10.6028/NIST.SP.800-38d, 2007,
              <https://nvlpubs.nist.gov/nistpubs/Legacy/SP/
              nistspecialpublication800-38d.pdf>.

   [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>.




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   [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>.

   [RFC2631]  Rescorla, E., "Diffie-Hellman Key Agreement Method",
              RFC 2631, DOI 10.17487/RFC2631, June 1999,
              <https://www.rfc-editor.org/info/rfc2631>.

   [RFC3370]  Housley, R., "Cryptographic Message Syntax (CMS)
              Algorithms", RFC 3370, DOI 10.17487/RFC3370, August 2002,
              <https://www.rfc-editor.org/info/rfc3370>.

   [RFC3394]  Schaad, J. and R. Housley, "Advanced Encryption Standard
              (AES) Key Wrap Algorithm", RFC 3394, DOI 10.17487/RFC3394,
              September 2002, <https://www.rfc-editor.org/info/rfc3394>.

   [RFC3560]  Housley, R., "Use of the RSAES-OAEP Key Transport
              Algorithm in Cryptographic Message Syntax (CMS)",
              RFC 3560, DOI 10.17487/RFC3560, July 2003,
              <https://www.rfc-editor.org/info/rfc3560>.

   [RFC3565]  Schaad, J., "Use of the Advanced Encryption Standard (AES)
              Encryption Algorithm in Cryptographic Message Syntax
              (CMS)", RFC 3565, DOI 10.17487/RFC3565, July 2003,
              <https://www.rfc-editor.org/info/rfc3565>.

   [RFC4056]  Schaad, J., "Use of the RSASSA-PSS Signature Algorithm in
              Cryptographic Message Syntax (CMS)", RFC 4056,
              DOI 10.17487/RFC4056, June 2005,
              <https://www.rfc-editor.org/info/rfc4056>.

   [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>.

   [RFC4231]  Nystrom, M., "Identifiers and Test Vectors for HMAC-SHA-
              224, HMAC-SHA-256, HMAC-SHA-384, and HMAC-SHA-512",
              RFC 4231, DOI 10.17487/RFC4231, December 2005,
              <https://www.rfc-editor.org/info/rfc4231>.




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   [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>.

   [RFC5753]  Turner, S. and D. Brown, "Use of Elliptic Curve
              Cryptography (ECC) Algorithms in Cryptographic Message
              Syntax (CMS)", RFC 5753, DOI 10.17487/RFC5753, January
              2010, <https://www.rfc-editor.org/info/rfc5753>.

   [RFC5754]  Turner, S., "Using SHA2 Algorithms with Cryptographic
              Message Syntax", RFC 5754, DOI 10.17487/RFC5754, January
              2010, <https://www.rfc-editor.org/info/rfc5754>.

   [RFC8017]  Moriarty, K., Ed., Kaliski, B., Jonsson, J., and A. Rusch,
              "PKCS #1: RSA Cryptography Specifications Version 2.2",
              RFC 8017, DOI 10.17487/RFC8017, November 2016,
              <https://www.rfc-editor.org/info/rfc8017>.

   [RFC8018]  Moriarty, K., Ed., Kaliski, B., and A. Rusch, "PKCS #5:
              Password-Based Cryptography Specification Version 2.1",
              RFC 8018, DOI 10.17487/RFC8018, January 2017,
              <https://www.rfc-editor.org/info/rfc8018>.

   [RFC8032]  Josefsson, S. and I. Liusvaara, "Edwards-Curve Digital
              Signature Algorithm (EdDSA)", RFC 8032,
              DOI 10.17487/RFC8032, January 2017,
              <https://www.rfc-editor.org/info/rfc8032>.

   [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>.

   [RFC8418]  Housley, R., "Use of the Elliptic Curve Diffie-Hellman Key
              Agreement Algorithm with X25519 and X448 in the
              Cryptographic Message Syntax (CMS)", RFC 8418,
              DOI 10.17487/RFC8418, August 2018,
              <https://www.rfc-editor.org/info/rfc8418>.

   [RFC8419]  Housley, R., "Use of Edwards-Curve Digital Signature
              Algorithm (EdDSA) Signatures in the Cryptographic Message
              Syntax (CMS)", RFC 8419, DOI 10.17487/RFC8419, August
              2018, <https://www.rfc-editor.org/info/rfc8419>.




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   [RFC8702]  Kampanakis, P. and Q. Dang, "Use of the SHAKE One-Way Hash
              Functions in the Cryptographic Message Syntax (CMS)",
              RFC 8702, DOI 10.17487/RFC8702, January 2020,
              <https://www.rfc-editor.org/info/rfc8702>.

   [RFC9044]  Housley, R., "Using the AES-GMAC Algorithm with the
              Cryptographic Message Syntax (CMS)", RFC 9044,
              DOI 10.17487/RFC9044, June 2021,
              <https://www.rfc-editor.org/info/rfc9044>.

   [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>.

12.  Informative References

   [ECRYPT.CSA.D5.4]
              University of Bristol, "Algorithms, Key Size and Protocols
              Report (2018)", March 2015,
              <https://www.ecrypt.eu.org/csa/documents/
              D5.4-FinalAlgKeySizeProt.pdf>.

   [NIST.SP.800-57pt1r5]
              Barker, Elaine., "Recommendation for key management:part 1
              - general", NIST NIST SP 800-57pt1r5,
              DOI 10.6028/NIST.SP.800-57pt1r5, May 2020,
              <https://nvlpubs.nist.gov/nistpubs/SpecialPublications/
              NIST.SP.800-57pt1r5.pdf>.

   [RFC8551]  Schaad, J., Ramsdell, B., and S. Turner, "Secure/
              Multipurpose Internet Mail Extensions (S/MIME) Version 4.0
              Message Specification", RFC 8551, DOI 10.17487/RFC8551,
              April 2019, <https://www.rfc-editor.org/info/rfc8551>.

   [RFC8692]  Kampanakis, P. and Q. Dang, "Internet X.509 Public Key
              Infrastructure: Additional Algorithm Identifiers for
              RSASSA-PSS and ECDSA Using SHAKEs", RFC 8692,
              DOI 10.17487/RFC8692, December 2019,
              <https://www.rfc-editor.org/info/rfc8692>.

Appendix A.  History of Changes

   Note: This appendix will be deleted in the final version of the
   document.

   From version 14 -> 15:



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   *  Providing changes addressing comment from Martin Duke and
      Zaheduzzaman Sarker regarding the introduction

   From version 13 -> 14:

   *  Providing changes addressing comments from GEN AD review

   From version 12 -> 13:

   *  Providing changes addressing comments from OPSDIR and GENART last
      call reviews

   From version 11 -> 12:

   *  Capitalized all headlines

   From version 10 -> 11:

   *  Changes on the tables in Section 7 after direct exchange with
      Quynh

   From version 09 -> 10:

   *  Removed the pre-RFC5378 work disclaimer after the RFC 4210 authors
      granted BCP78 rights to the IETF Trust
   *  Implemented the changes proposed by Quynh, (see thread "Quynh
      Action: draft-ietf-lamps-cmp-algorithms-08.txt") and removed
      markers for ToDos regarding this review of SHAKE and KMAC usage as
      well as on the tables in Section 7

   From version 08 -> 09:

   *  Updated IPR disclaimer

   From version 07 -> 08:

   *  Fixing issues from WG and AD review
   *  Adding Note to Section 2.2, 3.3, and 6.2.3 regarding usage of
      SHAKE and KMAC and added ToDo regarding checking respective notes
   *  Added two tables showing algorithms sorted by their strength to
      Section 7 and added ToDo regarding checking these tables
   *  Updates the algorithm use profile in Section 7.1
   *  Updated and added security consideration on SHAKE,
      PasswordBasedMac, KMAC, and symmetric key-based MAC functions and
      added ToDo regarding checking the security consideration on SHAKE

   From version 06 -> 07:




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   *  Fixing minor formatting nits

   From version 05 -> 06:

   *  Added text to Section 2 and Section 3.3 to clearly specify the
      hash algorithm to use for certConf messages for certificates
      signed with EdDSA (see thread "[CMP Updates] Hash algorithm to us
      for calculating certHash")
   *  Updated new RFC numbers for I-D.ietf-lamps-cms-aes-gmac-alg and I-
      D.ietf-lamps-crmf-update-algs

   From version 04 -> 05:

   *  Minor changes and corrections in wording

   From version 03 -> 04:

   *  Added John Gray to the list of authors due to his extensive
      support and valuable feedback
   *  Added some clarification of the use AES-GMAC to Section 6.2.1
   *  Extended the guidance on how to select a set of algorithms in
      Section 7 and deleted former Section 7.1
   *  Deleted the algorithms mandatory to support in Section 7.2 as
      discussed at IETF 110
   *  Extended the Security considerations in Section 9
   *  Minor changes in wording

   From version 02 -> 03:

   *  Moved former Appendix A to new Section 7 as suggested by Rich and
      Russ (see thread "I-D Action: draft-ietf-lamps-cmp-algorithms-
      02.txt")
   *  Added a column to Table 1 in Section 7.2 to reflect the changes to
      RFC 4210
   *  Updated Table 2 in Section 7.3
   *  Added a paragraph to Section 9 to discuss backward compatibility
      with RFC 4210
   *  Minor changes in wording

   From version 01 -> 02:

   *  Added Hans Aschauer, Mike Ounsworth, and Serge Mister as co-author
   *  Changed to XML V3
   *  Added SHAKE digest algorithm to Section 2 as discussed at IETF 109
   *  Deleted DSA from Section 3 as discussed at IETF 109
   *  Added RSASSA-PSS with SHAKE to Section 3
   *  Added SECP curves the section on ECDSA with SHA2, ECDSA with
      SHAKE, and EdDSA to Section 3 as discussed at IETF 109



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   *  Deleted static-static D-H and ECDH from Section 4.1 based on the
      discussion on the mailing list (see thread "[CMP Algorithms]
      Section 4.1.1 and 4.1.2 drop static-static (EC)DH key agreement
      algorithms for use in CMP")
   *  Added ECDH OIDs and SECP curves, as well as ECDH with curve25519
      and curve448 to Section 4.1 as discussed at IETF 109
   *  Deleted RSA-OAEP from Section 4.2 first as discussed at IETF 109,
      but re-added it after discussion on the mailing list (see thread
      "Mail regarding draft-ietf-lamps-cmp-algorithms")
   *  Added a paragraph to Section 4.3.1 to explain that the algorithms
      and key length for content encryption and key wrapping must be
      aligned as discussed on the mailing list (see thread "[CMP
      Algorithms] Use Key-Wrap with or without padding in Section 4.3
      and Section 5")
   *  Deleted AES-CCM and AES-GMC from and added AES-CBC to Section 5 as
      discussed at IETF 109
   *  Added Section 6.1.2 to offer PBMAC1 as discusses on the mailing
      list (see thread "Mail regarding draft-ietf-lamps-crmf-update-
      algs-02") and restructured text in Section 6 to be easier to
      differentiate between password- and shared-key-based MAC
   *  Deleted Diffie-Hellmann based MAC from Section 6 as is only
      relevant when using enrolling Diffie-Hellmann certificates
   *  Added AES-GMAC and SHAKE-based KMAC to Section 6 as discussed at
      IETF 109
   *  Extended Section 9 to mention Russ supporting with two additional
      I-Ds and name further supporters of the draft
   *  Added a first draft of a generic algorithm selection guideline to
      Appendix A
   *  Added a first proposal for mandatory algorithms for the
      Lightweight CMP Profile to Appendix A
   *  Minor changes in wording

   From version 00 -> 01:

   *  Changed sections Symmetric Key-Encryption Algorithms and Content
      Encryption Algorithms based on the discussion on the mailing list
      (see thread "[CMP Algorithms] Use Key-Wrap with or without padding
      in Section 4.3 and Section 5")
   *  Added Appendix A with updated algorithms profile for RDC4210
      Appendix D.2 and first proposal for the Lightweight CMP Profile
   *  Minor changes in wording

Authors' Addresses

   Hendrik Brockhaus (editor)
   Siemens AG
   Email: hendrik.brockhaus@siemens.com




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   Hans Aschauer
   Siemens AG
   Email: hans.aschauer@siemens.com


   Mike Ounsworth
   Entrust
   Email: mike.ounsworth@entrust.com


   John Gray
   Entrust
   Email: john.gray@entrust.com






































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