SHAKE in CMS: Use of the SHAKE One-Way Hash Functions in the Cryptographic Message Syntax (CMS)

Internet Engineering Task Force (IETF)                     P. Kampanakis
Request for Comments: 8702                                 Cisco Systems
Updates: 3370                                                    Q. Dang
Category: Standards Track                                           NIST
ISSN: 2070-1721                                             January 2020


  Use of the SHAKE One-Way Hash Functions in the Cryptographic Message
                              Syntax (CMS)

Abstract

   This document updates the "Cryptographic Message Syntax (CMS)
   Algorithms" (RFC 3370) and describes the conventions for using the
   SHAKE family of hash functions in the Cryptographic Message Syntax as
   one-way hash functions with the RSA Probabilistic Signature Scheme
   (RSASSA-PSS) and Elliptic Curve Digital Signature Algorithm (ECDSA).
   The conventions for the associated signer public keys in CMS are also
   described.

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/rfc8702.

Copyright Notice

   Copyright (c) 2020 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
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   described in the Simplified BSD License.

Table of Contents

   1.  Introduction
     1.1.  Terminology
   2.  Identifiers
   3.  Use in CMS
     3.1.  Message Digests
     3.2.  Signatures
       3.2.1.  RSASSA-PSS Signatures
       3.2.2.  ECDSA Signatures
     3.3.  Public Keys
     3.4.  Message Authentication Codes
   4.  IANA Considerations
   5.  Security Considerations
   6.  References
     6.1.  Normative References
     6.2.  Informative References
   Appendix A.  ASN.1 Module
   Acknowledgements
   Authors' Addresses

1.  Introduction

   "Cryptographic Message Syntax (CMS)" [RFC5652] describes syntax used
   to digitally sign, digest, authenticate, or encrypt arbitrary message
   contents.  "Cryptographic Message Syntax (CMS) Algorithms" [RFC3370]
   defines the use of common cryptographic algorithms with CMS.  This
   specification updates RFC 3370 and describes the use of the SHAKE128
   and SHAKE256 specified in [SHA3] as new hash functions in CMS.  In
   addition, it describes the use of these functions with the RSA
   Probabilistic Signature Scheme (RSASSA-PSS) signature algorithm
   [RFC8017] and the Elliptic Curve Digital Signature Algorithm (ECDSA)
   [X9.62] with the CMS signed-data content type.

   In the SHA-3 family, two extendable-output functions (SHAKEs),
   SHAKE128 and SHAKE256, are defined.  Four other hash function
   instances (SHA3-224, SHA3-256, SHA3-384, and SHA3-512) are also
   defined but are out of scope for this document.  A SHAKE is a
   variable-length hash function defined as SHAKE(M, d) where the output
   is a d-bit-long digest of message M.  The corresponding collision and
   second-preimage-resistance strengths for SHAKE128 are min(d/2,128)
   and min(d,128) bits, respectively (see Appendix A.1 of [SHA3]).  And
   the corresponding collision and second-preimage-resistance strengths
   for SHAKE256 are min(d/2,256) and min(d,256) bits, respectively.  In
   this specification, we use d=256 (for SHAKE128) and d=512 (for
   SHAKE256).

   A SHAKE can be used in CMS as the message digest function (to hash
   the message to be signed) in RSASSA-PSS and ECDSA, as the message
   authentication code, and as the mask generation function (MGF) in
   RSASSA-PSS.  This specification describes the identifiers for SHAKEs
   to be used in CMS and their meanings.

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.

2.  Identifiers

   This section identifies eight new object identifiers (OIDs) for using
   SHAKE128 and SHAKE256 in CMS.

   Two object identifiers for SHAKE128 and SHAKE256 hash functions are
   defined in [shake-nist-oids], and we include them here for
   convenience.

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

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

   In this specification, when using the id-shake128 or id-shake256
   algorithm identifiers, the parameters MUST be absent.  That is, the
   identifier SHALL be a SEQUENCE of one component, the OID.

   [RFC8692] defines two identifiers for RSASSA-PSS signatures using
   SHAKEs, which we include here for convenience.

     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 }

   The same RSASSA-PSS algorithm identifiers can be used for identifying
   public keys and signatures.

   [RFC8692] also defines two algorithm identifiers of ECDSA signatures
   using SHAKEs, which we include here for convenience.

     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 }

   The parameters for the four RSASSA-PSS and ECDSA identifiers MUST be
   absent.  That is, each identifier SHALL be a SEQUENCE of one
   component, the OID.

   In [shake-nist-oids], the National Institute of Standards and
   Technology (NIST) defines two object identifiers for Keccak message
   authentication codes (KMACs) using SHAKE128 and SHAKE256, and we
   include them here for convenience.

      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 }

   The parameters for id-KmacWithSHAKE128 and id-KmacWithSHAKE256 are
   OPTIONAL.

   Sections 3.1, 3.2.1, 3.2.2, and 3.4 specify the required output
   length for each use of SHAKE128 or SHAKE256 in message digests,
   RSASSA-PSS, ECDSA, and KMAC.

3.  Use in CMS

3.1.  Message Digests

   The id-shake128 and id-shake256 OIDs (see Section 2) can be used as
   the digest algorithm identifiers located in the SignedData,
   SignerInfo, DigestedData, and the AuthenticatedData digestAlgorithm
   fields in CMS [RFC5652].  The OID encoding MUST omit the parameters
   field and the output length of SHAKE128 or SHAKE256 as the message
   digest MUST be 32 or 64 bytes, respectively.

   The digest values are located in the DigestedData field and the
   Message Digest authenticated attribute included in the
   signedAttributes of the SignedData signerInfos.  In addition, digest
   values are input to signature algorithms.  The digest algorithm MUST
   be the same as the message hash algorithms used in signatures.

3.2.  Signatures

   In CMS, signature algorithm identifiers are located in the SignerInfo
   signatureAlgorithm field of signed-data content type and
   countersignature attribute.  Signature values are located in the
   SignerInfo signature field of signed-data content type and
   countersignature attribute.

   Conforming implementations that process RSASSA-PSS and ECDSA with
   SHAKE signatures when processing CMS data MUST recognize the
   corresponding OIDs specified in Section 2.

   When using RSASSA-PSS or ECDSA with SHAKEs, the RSA modulus or ECDSA
   curve order SHOULD be chosen in line with the SHAKE output length.
   Refer to Section 5 for more details.

3.2.1.  RSASSA-PSS Signatures

   The RSASSA-PSS algorithm is defined in [RFC8017].  When id-RSASSA-
   PSS-SHAKE128 or id-RSASSA-PSS-SHAKE256 (specified in Section 2) is
   used, the encoding MUST omit the parameters field.  That is, the
   AlgorithmIdentifier SHALL be a SEQUENCE of one component: id-RSASSA-
   PSS-SHAKE128 or id-RSASSA-PSS-SHAKE256.  [RFC4055] defines RSASSA-
   PSS-params that are used to define the algorithms and inputs to the
   algorithm.  This specification does not use parameters because the
   hash, mask generation algorithm, trailer, and salt are embedded in
   the OID definition.

   The hash algorithm used to hash a message being signed and the hash
   algorithm as the mask generation function used in RSASSA-PSS MUST be
   the same: both SHAKE128 or both SHAKE256.  The output length of the
   hash algorithm that hashes the message SHALL be 32 (for SHAKE128) or
   64 bytes (for SHAKE256).

   The mask generation function takes an octet string of variable length
   and a desired output length as input, and outputs an octet string of
   the desired length.  In RSASSA-PSS with SHAKEs, the SHAKEs MUST be
   used natively as the MGF, instead of the MGF1 algorithm that uses the
   hash function in multiple iterations, as specified in Appendix B.2.1
   of [RFC8017].  In other words, the MGF is defined as the SHAKE128 or
   SHAKE256 with input being the mgfSeed for id-RSASSA-PSS-SHAKE128 and
   id-RSASSA-PSS-SHAKE256, respectively.  The mgfSeed is an octet string
   used as the seed to generate the mask [RFC8017].  As explained in
   Step 9 of Section 9.1.1 of [RFC8017], the output length of the MGF is
   emLen - hLen - 1 bytes. emLen is the maximum message length
   ceil((n-1)/8), where n is the RSA modulus in bits. hLen is 32 and 64
   bytes for id-RSASSA-PSS-SHAKE128 and id-RSASSA-PSS-SHAKE256,
   respectively.  Thus, when SHAKE is used as the MGF, the SHAKE output
   length maskLen is (8*emLen - 264) or (8*emLen - 520) bits,
   respectively.  For example, when RSA modulus n is 2048, the output
   length of SHAKE128 or SHAKE256 as the MGF will be 1784 or 1528 bits
   when id-RSASSA-PSS-SHAKE128 or id-RSASSA-PSS-SHAKE256 is used,
   respectively.

   The RSASSA-PSS saltLength MUST be 32 bytes for id-RSASSA-PSS-SHAKE128
   or 64 bytes for id-RSASSA-PSS-SHAKE256.  Finally, the trailerField
   MUST be 1, which represents the trailer field with hexadecimal value
   0xBC [RFC8017].

3.2.2.  ECDSA Signatures

   The Elliptic Curve Digital Signature Algorithm (ECDSA) is defined in
   [X9.62].  When the id-ecdsa-with-shake128 or id-ecdsa-with-shake256
   (specified in Section 2) algorithm identifier appears, the respective
   SHAKE function is used as the hash.  The encoding MUST omit the
   parameters field.  That is, the AlgorithmIdentifier SHALL be a
   SEQUENCE of one component, the OID id-ecdsa-with-shake128 or id-
   ecdsa-with-shake256.

   For simplicity and compliance with the ECDSA standard specification
   [X9.62], the output length of the hash function must be explicitly
   determined.  The output length for SHAKE128 or SHAKE256 used in ECDSA
   MUST be 32 or 64 bytes, respectively.

   Conforming Certification Authority (CA) implementations that generate
   ECDSA with SHAKE signatures in certificates or Certificate Revocation
   Lists (CRLs) SHOULD generate such signatures with a deterministically
   generated, nonrandom k in accordance with all the requirements
   specified in [RFC6979].  They MAY also generate such signatures in
   accordance with all other recommendations in [X9.62] or [SEC1] if
   they have a stated policy that requires conformance to those
   standards.  Those standards have not specified SHAKE128 and SHAKE256
   as hash algorithm options.  However, SHAKE128 and SHAKE256 with
   output length being 32 and 64 octets, respectively, can be used
   instead of 256 and 512-bit output hash algorithms, such as SHA256 and
   SHA512.

3.3.  Public Keys

   In CMS, the signer's public key algorithm identifiers are located in
   the OriginatorPublicKey's algorithm attribute.  The conventions and
   encoding for RSASSA-PSS and ECDSA public keys algorithm identifiers
   are as specified in Section 2.3 of [RFC3279], Section 3.1 of
   [RFC4055], and Section 2.1 of [RFC5480].

   Traditionally, the rsaEncryption object identifier is used to
   identify RSA public keys.  The rsaEncryption object identifier
   continues to identify the public key when the RSA private key owner
   does not wish to limit the use of the public key exclusively to
   RSASSA-PSS with SHAKEs.  When the RSA private key owner wishes to
   limit the use of the public key exclusively to RSASSA-PSS, the
   AlgorithmIdentifier for RSASSA-PSS defined in Section 2 SHOULD be
   used as the algorithm attribute in the OriginatorPublicKey sequence.
   Conforming client implementations that process RSASSA-PSS with SHAKE
   public keys in CMS message MUST recognize the corresponding OIDs in
   Section 2.

   Conforming implementations MUST specify and process the algorithms
   explicitly by using the OIDs specified in Section 2 when encoding
   ECDSA with SHAKE public keys in CMS messages.

   The identifier parameters, as explained in Section 2, MUST be absent.

3.4.  Message Authentication Codes

   Keccak message authentication code (KMAC) is specified in
   [SP800-185].  In CMS, KMAC algorithm identifiers are located in the
   AuthenticatedData macAlgorithm field.  The KMAC values are located in
   the AuthenticatedData mac field.

   When the id-KmacWithSHAKE128 or id-KmacWithSHAKE256 OID is used as
   the MAC algorithm identifier, the parameters field is optional
   (absent or present).  If absent, the SHAKE256 output length used in
   KMAC is 32 or 64 bytes, respectively, and the customization string is
   an empty string by default.

   Conforming implementations that process KMACs with the SHAKEs when
   processing CMS data MUST recognize these identifiers.

   When calculating the KMAC output, the variable N is 0xD2B282C2, S is
   an empty string, and L (the integer representing the requested output
   length in bits) is 256 or 512 for KmacWithSHAKE128 or
   KmacWithSHAKE256, respectively, in this specification.

4.  IANA Considerations

   One object identifier for the ASN.1 module in Appendix A was updated
   in the "Structure of Management Information (SMI) Security for S/MIME
   Module Identifier (1.2.840.113549.1.9.16.0)" registry:

   +---------+----------------------+------------+
   | Decimal |     Description      | References |
   +=========+======================+============+
   |    70   | CMSAlgsForSHAKE-2019 |  RFC 8702  |
   +---------+----------------------+------------+

                       Table 1

5.  Security Considerations

   This document updates [RFC3370].  The security considerations section
   of that document applies to this specification as well.

   NIST has defined appropriate use of the hash functions in terms of
   the algorithm strengths and expected time frames for secure use in
   Special Publications (SPs) [SP800-78-4] and [SP800-107].  These
   documents can be used as guides to choose appropriate key sizes for
   various security scenarios.

   SHAKE128 with an output length of 32 bytes offers 128 bits of
   collision and preimage resistance.  Thus, SHAKE128 OIDs in this
   specification are RECOMMENDED with a 2048- (112-bit security) or
   3072-bit (128-bit security) RSA modulus or curves with a group order
   of 256 bits (128-bit security).  SHAKE256 with a 64-byte output
   length offers 256 bits of collision and preimage resistance.  Thus,
   the SHAKE256 OIDs in this specification are RECOMMENDED with 4096-bit
   RSA modulus or higher or curves with group order of at least 512
   bits, such as NIST curve P-521 (256-bit security).  Note that we
   recommended a 4096-bit RSA because we would need a 15360-bit modulus
   for 256 bits of security, which is impractical for today's
   technology.

   When more than two parties share the same message-authentication key,
   data origin authentication is not provided.  Any party that knows the
   message-authentication key can compute a valid MAC; therefore, the
   content could originate from any one of the parties.

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>.

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

   [RFC4055]  Schaad, J., Kaliski, B., and R. Housley, "Additional
              Algorithms and Identifiers for RSA Cryptography for use in
              the Internet X.509 Public Key Infrastructure Certificate
              and Certificate Revocation List (CRL) Profile", RFC 4055,
              DOI 10.17487/RFC4055, June 2005,
              <https://www.rfc-editor.org/info/rfc4055>.

   [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>.

   [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>.

   [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>.

   [SHA3]     National Institute of Standards and Technology (NIST),
              "SHA-3 Standard: Permutation-Based Hash and Extendable-
              Output Functions", FIPS PUB 202,
              DOI 10.6028/NIST.FIPS.202, August 2015,
              <https://nvlpubs.nist.gov/nistpubs/FIPS/
              NIST.FIPS.202.pdf>.

   [SP800-185]
              National Institute of Standards and Technology (NIST),
              "SHA-3 Derived Functions: cSHAKE, KMAC, TupleHash and
              ParallelHash", NIST Special Publication 800-185,
              DOI 10.6028/NIST.SP.800-185, December 2016,
              <http://nvlpubs.nist.gov/nistpubs/SpecialPublications/
              NIST.SP.800-185.pdf>.

6.2.  Informative References

   [CMS-SHA3] Housley, R., "Use of the SHA3 One-way Hash Functions in
              the Cryptographic Message Syntax (CMS)", Work in Progress,
              Internet-Draft, draft-housley-lamps-cms-sha3-hash-00, 27
              March 2017, <https://tools.ietf.org/html/draft-housley-
              lamps-cms-sha3-hash-00>.

   [RFC3279]  Bassham, L., Polk, W., and R. Housley, "Algorithms and
              Identifiers for the Internet X.509 Public Key
              Infrastructure Certificate and Certificate Revocation List
              (CRL) Profile", RFC 3279, DOI 10.17487/RFC3279, April
              2002, <https://www.rfc-editor.org/info/rfc3279>.

   [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>.

   [RFC5911]  Hoffman, P. and J. Schaad, "New ASN.1 Modules for
              Cryptographic Message Syntax (CMS) and S/MIME", RFC 5911,
              DOI 10.17487/RFC5911, June 2010,
              <https://www.rfc-editor.org/info/rfc5911>.

   [RFC6268]  Schaad, J. and S. Turner, "Additional New ASN.1 Modules
              for the Cryptographic Message Syntax (CMS) and the Public
              Key Infrastructure Using X.509 (PKIX)", RFC 6268,
              DOI 10.17487/RFC6268, July 2011,
              <https://www.rfc-editor.org/info/rfc6268>.

   [RFC6979]  Pornin, T., "Deterministic Usage of the Digital Signature
              Algorithm (DSA) and Elliptic Curve Digital Signature
              Algorithm (ECDSA)", RFC 6979, DOI 10.17487/RFC6979, August
              2013, <https://www.rfc-editor.org/info/rfc6979>.

   [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>.

   [SEC1]     Standards for Efficient Cryptography Group, "SEC 1:
              Elliptic Curve Cryptography", May 2009,
              <http://www.secg.org/sec1-v2.pdf>.

   [shake-nist-oids]
              National Institute of Standards and Technology (NIST),
              "Computer Security Objects Register", October 2019,
              <https://csrc.nist.gov/Projects/Computer-Security-Objects-
              Register/Algorithm-Registration>.

   [SP800-107]
              National Institute of Standards and Technology (NIST),
              "Recommendation for Applications Using Approved Hash
              Algorithms", Draft NIST Special Publication 800-107
              Revised, August 2012,
              <https://nvlpubs.nist.gov/nistpubs/Legacy/SP/
              nistspecialpublication800-107r1.pdf>.

   [SP800-78-4]
              National Institute of Standards and Technology (NIST),
              "Cryptographic Algorithms and Key Sizes for Personal
              Identity Verification", NIST Special Publication 800-78-4,
              DOI 10.6028/NIST.SP.800-78-4, May 2015,
              <https://nvlpubs.nist.gov/nistpubs/SpecialPublications/
              NIST.SP.800-78-4.pdf>.

   [X9.62]    American National Standard for Financial Services (ANSI),
              "Public Key Cryptography for the Financial Services
              Industry: the Elliptic Curve Digital Signature Algorithm
              (ECDSA)", ANSI X9.62, November 2005.

Appendix A.  ASN.1 Module

   This appendix includes the ASN.1 modules for SHAKEs in CMS.  This
   module includes some ASN.1 from other standards for reference.

   CMSAlgsForSHAKE-2019 { iso(1) member-body(2) us(840)
        rsadsi(113549) pkcs(1) pkcs-9(9) smime(16) modules(0)
        id-mod-cms-shakes-2019(70) }

   DEFINITIONS EXPLICIT TAGS ::=

   BEGIN

   -- EXPORTS ALL;

   IMPORTS

   DIGEST-ALGORITHM, MAC-ALGORITHM, SMIME-CAPS
   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) }

   RSAPublicKey, rsaEncryption, id-ecPublicKey
   FROM PKIXAlgs-2009 { iso(1) identified-organization(3) dod(6)
        internet(1) security(5) mechanisms(5) pkix(7) id-mod(0)
        id-mod-pkix1-algorithms2008-02(56) }

   sa-rsassapssWithSHAKE128, sa-rsassapssWithSHAKE256,
   sa-ecdsaWithSHAKE128, sa-ecdsaWithSHAKE256
   FROM PKIXAlgsForSHAKE-2019 {
      iso(1) identified-organization(3) dod(6)
      internet(1) security(5) mechanisms(5) pkix(7) id-mod(0)
      id-mod-pkix1-shakes-2019(94) } ;

   -- Message digest Algorithms (mda-)
   -- used in SignedData, SignerInfo, DigestedData,
   -- and the AuthenticatedData digestAlgorithm
   -- fields in CMS
   --
   --  This expands MessageAuthAlgs from [RFC5652] and
   --  MessageDigestAlgs in [RFC5753]
   --
   -- MessageDigestAlgs DIGEST-ALGORITHM ::= {
   --  mda-shake128   |
   --  mda-shake256,
   --  ...
   -- }

   --
   -- One-Way Hash Functions
   -- SHAKE128
   mda-shake128 DIGEST-ALGORITHM ::= {
     IDENTIFIER id-shake128  -- with output length 32 bytes.
   }
   id-shake128 OBJECT IDENTIFIER ::= { joint-iso-itu-t(2) country(16)
                                       us(840) organization(1) gov(101)
                                       csor(3) nistAlgorithm(4)
                                       hashAlgs(2) 11 }

   -- SHAKE256
   mda-shake256 DIGEST-ALGORITHM ::= {
     IDENTIFIER id-shake256  -- with output length 64 bytes.
   }
   id-shake256 OBJECT IDENTIFIER ::= { joint-iso-itu-t(2) country(16)
                                       us(840) organization(1) gov(101)
                                       csor(3) nistAlgorithm(4)
                                       hashAlgs(2) 12 }

   --
   -- Public key algorithm identifiers located in the
   -- OriginatorPublicKey's algorithm attribute in CMS.
   -- And Signature identifiers used in SignerInfo
   -- signatureAlgorithm field of signed-data content
   -- type and countersignature attribute in CMS.
   --
   -- From RFC 5280, for reference:
   -- rsaEncryption OBJECT IDENTIFIER ::=  { pkcs-1 1 }
      -- When the rsaEncryption algorithm identifier is used
      -- for a public key, the AlgorithmIdentifier parameters
      -- field MUST contain NULL.
   --
   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 }

      -- When the id-RSASSA-PSS-* algorithm identifiers are used
      -- for a public key or signature in CMS, the AlgorithmIdentifier
      -- parameters field MUST be absent.  The message digest algorithm
      -- used in RSASSA-PSS MUST be SHAKE128 or SHAKE256 with a 32- or
      -- 64-byte output length, respectively.  The mask generation
      -- function MUST be SHAKE128 or SHAKE256 with an output length
      -- of (8*ceil((n-1)/8) - 264) or (8*ceil((n-1)/8) - 520) bits,
      -- respectively, where n is the RSA modulus in bits.
      -- The RSASSA-PSS saltLength MUST be 32 or 64 bytes, respectively.
      -- The trailerField MUST be 1, which represents the trailer
      -- field with hexadecimal value 0xBC.  Regardless of
      -- id-RSASSA-PSS-* or rsaEncryption being used as the
      -- AlgorithmIdentifier of the OriginatorPublicKey, the RSA
      -- public key MUST be encoded using the RSAPublicKey type.

   -- From RFC 4055, for reference:
   -- RSAPublicKey ::= SEQUENCE {
   --   modulus INTEGER, -- -- n
   --   publicExponent INTEGER } -- -- e

   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 }

      -- When the id-ecdsa-with-shake* algorithm identifiers are
      -- used in CMS, the AlgorithmIdentifier parameters field
      -- MUST be absent and the signature algorithm should be
      -- deterministic ECDSA [RFC6979].  The message digest MUST
      -- be SHAKE128 or SHAKE256 with a 32- or 64-byte output
      -- length, respectively.  In both cases, the ECDSA public key,
      -- MUST be encoded using the id-ecPublicKey type.

   -- From RFC 5480, for reference:
   -- id-ecPublicKey OBJECT IDENTIFIER ::= {
   --    iso(1) member-body(2) us(840) ansi-X9-62(10045) keyType(2) 1 }
        -- The id-ecPublicKey parameters must be absent or present
        -- and are defined as:
   -- ECParameters ::= CHOICE {
   --     namedCurve         OBJECT IDENTIFIER
   --     -- -- implicitCurve   NULL
   --     -- -- specifiedCurve  SpecifiedECDomain
   --  }

   -- This expands SignatureAlgs from [RFC5912]
   --
   -- SignatureAlgs SIGNATURE-ALGORITHM ::= {
   --   sa-rsassapssWithSHAKE128 |
   --   sa-rsassapssWithSHAKE256 |
   --   sa-ecdsaWithSHAKE128 |
   --   sa-ecdsaWithSHAKE256,
   --   ...
   -- }

   -- This expands MessageAuthAlgs from [RFC5652] and [RFC6268]
   --
   -- Message Authentication (maca-) Algorithms
   -- used in AuthenticatedData macAlgorithm in CMS
   --
   MessageAuthAlgs MAC-ALGORITHM ::= {
       maca-KMACwithSHAKE128   |
       maca-KMACwithSHAKE256,
       ...
   }

   -- This expands SMimeCaps from [RFC5911]
   --
   SMimeCaps SMIME-CAPS ::= {
      -- sa-rsassapssWithSHAKE128.&smimeCaps |
      -- sa-rsassapssWithSHAKE256.&smimeCaps |
      -- sa-ecdsaWithSHAKE128.&smimeCaps |
      -- sa-ecdsaWithSHAKE256.&smimeCaps,
      maca-KMACwithSHAKE128.&smimeCaps   |
      maca-KMACwithSHAKE256.&smimeCaps,
      ...
    }

   --
   -- KMAC with SHAKE128
   maca-KMACwithSHAKE128 MAC-ALGORITHM ::= {
         IDENTIFIER id-KMACWithSHAKE128
         PARAMS TYPE KMACwithSHAKE128-params ARE optional
           -- If KMACwithSHAKE128-params parameters are absent,
           -- the SHAKE128 output length used in KMAC is 256 bits
           -- and the customization string is an empty string.
         IS-KEYED-MAC TRUE
         SMIME-CAPS {IDENTIFIED BY id-KMACWithSHAKE128}
   }
   id-KMACWithSHAKE128 OBJECT IDENTIFIER ::=  { joint-iso-itu-t(2)
                                country(16) us(840) organization(1)
                                gov(101) csor(3) nistAlgorithm(4)
                                hashAlgs(2) 19 }
   KMACwithSHAKE128-params ::= SEQUENCE {
     kMACOutputLength     INTEGER DEFAULT 256, -- Output length in bits
     customizationString  OCTET STRING DEFAULT ''H
   }

   -- KMAC with SHAKE256
   maca-KMACwithSHAKE256 MAC-ALGORITHM ::= {
         IDENTIFIER id-KMACWithSHAKE256
         PARAMS TYPE KMACwithSHAKE256-params ARE optional
            -- If KMACwithSHAKE256-params parameters are absent,
            -- the SHAKE256 output length used in KMAC is 512 bits
            -- and the customization string is an empty string.
         IS-KEYED-MAC TRUE
         SMIME-CAPS {IDENTIFIED BY id-KMACWithSHAKE256}
   }
   id-KMACWithSHAKE256 OBJECT IDENTIFIER ::=  { joint-iso-itu-t(2)
                               country(16) us(840) organization(1)
                               gov(101) csor(3) nistAlgorithm(4)
                               hashAlgs(2) 20 }
   KMACwithSHAKE256-params ::= SEQUENCE {
      kMACOutputLength     INTEGER DEFAULT 512, -- Output length in bits
      customizationString  OCTET STRING DEFAULT ''H
   }

   END

Acknowledgements

   This document is based on Russ Housley's document [CMS-SHA3].  It
   replaces SHA3 hash functions by SHAKE128 and SHAKE256, as the LAMPS
   WG agreed.

   The authors would like to thank Russ Housley for his guidance and
   very valuable contributions with the ASN.1 module.  Valuable feedback
   was also provided by Eric Rescorla.

Authors' Addresses

   Panos Kampanakis
   Cisco Systems

   Email: pkampana@cisco.com


   Quynh Dang
   NIST
   100 Bureau Drive
   Gaithersburg, MD 20899
   United States of America

   Email: quynh.Dang@nist.gov