



LAMPS WG                                                   P. Kampanakis
Internet-Draft                                             Cisco Systems
Updates: 3279 (if approved)                                      Q. Dang
Intended status: Standards Track                                    NIST
Expires: January 22, 2020                                  July 21, 2019


     Internet X.509 Public Key Infrastructure: Additional Algorithm
           Identifiers for RSASSA-PSS and ECDSA using SHAKEs
                     draft-ietf-lamps-pkix-shake-15

Abstract

   Digital signatures are used to sign messages, X.509 certificates and
   CRLs.  This document updates the "Algorithms and Identifiers for the
   Internet X.509 Public Key Infrastructure Certificate and Certificate
   Revocation List Profile" (RFC3279) and describes the conventions for
   using the SHAKE function family in Internet X.509 certificates and
   revocation lists as one-way hash functions with the RSA Probabilistic
   signature and ECDSA signature algorithms.  The conventions for the
   associated subject public keys are also described.

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 January 22, 2020.

Copyright Notice

   Copyright (c) 2019 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (https://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents



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   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Change Log  . . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   5
   3.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   5
   4.  Identifiers . . . . . . . . . . . . . . . . . . . . . . . . .   5
   5.  Use in PKIX . . . . . . . . . . . . . . . . . . . . . . . . .   6
     5.1.  Signatures  . . . . . . . . . . . . . . . . . . . . . . .   6
       5.1.1.  RSASSA-PSS Signatures . . . . . . . . . . . . . . . .   7
       5.1.2.  ECDSA Signatures  . . . . . . . . . . . . . . . . . .   8
     5.2.  Public Keys . . . . . . . . . . . . . . . . . . . . . . .   9
   6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   9
   7.  Security Considerations . . . . . . . . . . . . . . . . . . .  10
   8.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  10
   9.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  11
     9.1.  Normative References  . . . . . . . . . . . . . . . . . .  11
     9.2.  Informative References  . . . . . . . . . . . . . . . . .  12
   Appendix A.  ASN.1 module . . . . . . . . . . . . . . . . . . . .  13
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  17

1.  Change Log

   [ EDNOTE: Remove this section before publication. ]

   o  draft-ietf-lamps-pkix-shake-15:

      *  Minor editorial nits.

   o  draft-ietf-lamps-pkix-shake-14:

      *  Fixing error with incorrect preimage resistance bits for SHA128
         and SHA256.

   o  draft-ietf-lamps-pkix-shake-13:

      *  Addressing one applicable comment from Dan M. about sec levels
         while in secdir review of draft-ietf-lamps-cms-shakes.

      *  Addressing comment from Scott B.'s opsdir review about
         references in the abstract.

   o  draft-ietf-lamps-pkix-shake-12:



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      *  Nits identified by Roman, Eric V.  Ben K., Barry L. in ballot
         position review.

   o  draft-ietf-lamps-pkix-shake-11:

      *  Nits identified by Roman in AD Review.

   o  draft-ietf-lamps-pkix-shake-10:

      *  Updated IANA considerations section to request for OID
         assignments.

   o  draft-ietf-lamps-pkix-shake-09:

      *  Fixed minor text nits.

      *  Added text name allocation for SHAKEs in IANA considerations.

      *  Updates in Sec Considerations section.

   o  draft-ietf-lamps-pkix-shake-08:

      *  Small nits from Russ while in WGLC.

   o  draft-ietf-lamps-pkix-shake-07:

      *  Incorporated Eric's suggestion from WGLC.

   o  draft-ietf-lamps-pkix-shake-06:

      *  Added informative references.

      *  Updated ASN.1 so it compiles.

      *  Updated IANA considerations.

   o  draft-ietf-lamps-pkix-shake-05:

      *  Added RFC8174 reference and text.

      *  Explicitly explained why RSASSA-PSS-params are omitted in
         section 5.1.1.

      *  Simplified Public Keys section by removing redundant info from
         RFCs.

   o  draft-ietf-lamps-pkix-shake-04:




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      *  Removed paragraph suggesting KMAC to be used in generating k in
         Deterministic ECDSA.  That should be RFC6979-bis.

      *  Removed paragraph from Security Considerations that talks about
         randomness of k because we are using deterministic ECDSA.

      *  Various ASN.1 fixes.

      *  Text fixes.

   o  draft-ietf-lamps-pkix-shake-03:

      *  Updates based on suggestions and clarifications by Jim.

      *  Added ASN.1.

   o  draft-ietf-lamps-pkix-shake-02:

      *  Significant reorganization of the sections to simplify the
         introduction, the new OIDs and their use in PKIX.

      *  Added new OIDs for RSASSA-PSS that hardcode hash, salt and MGF,
         according the WG consensus.

      *  Updated Public Key section to use the new RSASSA-PSS OIDs and
         clarify the algorithm identifier usage.

      *  Removed the no longer used SHAKE OIDs from section 3.1.

      *  Consolidated subsection for message digest algorithms.

      *  Text fixes.

   o  draft-ietf-lamps-pkix-shake-01:

      *  Changed titles and section names.

      *  Removed DSA after WG discussions.

      *  Updated shake OID names and parameters, added MGF1 section.

      *  Updated RSASSA-PSS section.

      *  Added Public key algorithm OIDs.

      *  Populated Introduction and IANA sections.

   o  draft-ietf-lamps-pkix-shake-00:



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      *  Initial version

2.  Introduction

   [RFC3279] defines cryptographic algorithm identifiers for the
   Internet X.509 Certificate and Certificate Revocation Lists (CRL)
   profile [RFC5280].  This document updates RFC3279 and defines
   identifiers for several cryptographic algorithms that use variable
   length output SHAKE functions introduced in [SHA3] which can be used
   with .

   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-bits-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 (Appendix A.1 [SHA3]).
   And the corresponding collision and second-preimage-resistance
   strengths for SHAKE256 are min(d/2,256) and min(d,256) bits,
   respectively.

   A SHAKE can be used as the message digest function (to hash the
   message to be signed) in RSASSA-PSS [RFC8017] and ECDSA [X9.62] and
   as the hash in the mask generation function (MGF) in RSASSA-PSS.

3.  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.

4.  Identifiers

   This section defines four new object identifiers (OIDs), for RSASSA-
   PSS and ECDSA with each of SHAKE128 and SHAKE256.  The same algorithm
   identifiers can be used for identifying a public key in RSASSA-PSS.

   The new identifiers for RSASSA-PSS signatures using SHAKEs are below.









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     id-RSASSA-PSS-SHAKE128  OBJECT IDENTIFIER  ::=  { iso(1)
               identified-organization(3) dod(6) internet(1)
               security(5) mechanisms(5) pkix(7) algorithms(6)
               TBD1 }

     id-RSASSA-PSS-SHAKE256  OBJECT IDENTIFIER  ::=  { iso(1)
               identified-organization(3) dod(6) internet(1)
               security(5) mechanisms(5) pkix(7) algorithms(6)
               TBD2 }

   The new algorithm identifiers of ECDSA signatures using SHAKEs are
   below.



     id-ecdsa-with-shake128 OBJECT IDENTIFIER  ::=  { iso(1)
               identified-organization(3) dod(6) internet(1)
               security(5) mechanisms(5) pkix(7) algorithms(6)
               TBD3 }

     id-ecdsa-with-shake256 OBJECT IDENTIFIER  ::=  { iso(1)
               identified-organization(3) dod(6) internet(1)
               security(5) mechanisms(5) pkix(7) algorithms(6)
               TBD4 }

   The parameters for the four identifiers above MUST be absent.  That
   is, the identifier SHALL be a SEQUENCE of one component, the OID.

   Section 5.1.1 and Section 5.1.2 specify the required output length
   for each use of SHAKE128 or SHAKE256 in RSASSA-PSS and ECDSA.  In
   summary, when hashing messages to be signed, output lengths of
   SHAKE128 and SHAKE256 are 256 and 512 bits respectively.  When the
   SHAKEs are used as mask generation functions RSASSA-PSS, their output
   length is (8*ceil((n-1)/8) - 264) or (8*ceil((n-1)/8) - 520) bits,
   respectively, where n is the RSA modulus size in bits.

5.  Use in PKIX

5.1.  Signatures

   Signatures are used in a number of different ASN.1 structures.  As
   shown in the ASN.1 representation from [RFC5280] below, in an X.509
   certificate, a signature is encoded with an algorithm identifier in
   the signatureAlgorithm attribute and a signatureValue attribute that
   contains the actual signature.






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      Certificate  ::=  SEQUENCE  {
         tbsCertificate       TBSCertificate,
         signatureAlgorithm   AlgorithmIdentifier,
         signatureValue       BIT STRING  }

   The identifiers defined in Section 4 can be used as the
   AlgorithmIdentifier in the signatureAlgorithm field in the sequence
   Certificate and the signature field in the sequence TBSCertificate in
   X.509 [RFC5280].  The parameters of these signature algorithms are
   absent as explained in Section 4.

   Conforming CA implementations MUST specify the algorithms explicitly
   by using the OIDs specified in Section 4 when encoding RSASSA-PSS or
   ECDSA with SHAKE signatures in certificates and CRLs.  Conforming
   client implementations that process certificates and CRLs using
   RSASSA-PSS or ECDSA with SHAKE MUST recognize the corresponding OIDs.
   Encoding rules for RSASSA-PSS and ECDSA signature values are
   specified in [RFC4055] and [RFC5480], respectively.

   When using RSASSA-PSS or ECDSA with SHAKEs, the RSA modulus and ECDSA
   curve order SHOULD be chosen in line with the SHAKE output length.
   Refer to Section 7 for more details.

5.1.1.  RSASSA-PSS Signatures

   The RSASSA-PSS algorithm is defined in [RFC8017].  When id-RSASSA-
   PSS-SHAKE128 or id-RSASSA-PSS-SHAKE256 specified in Section 4 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 to hash a message being signed and the hash
   algorithm used as the mask generation function in RSASSA-PSS MUST be
   the same: both SHAKE128 or both SHAKE256.  The output length of the
   hash algorithm which 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 function, instead of the MGF1 algorithm that
   uses the hash function in multiple iterations as specified in
   Section B.2.1 of [RFC8017].  In other words, the MGF is defined as
   the SHAKE128 or SHAKE256 output of the mgfSeed for id-RSASSA-PSS-



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   SHAKE128 and id-RSASSA-PSS-SHAKE256, respectively.  The mgfSeed is
   the seed from which mask is generated, an octet string [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].

5.1.2.  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 4) algorithm identifier appears, the respective
   SHAKE function (SHAKE128 or SHAKE256) 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,
   the output length of the hash function must be explicitly determined.
   The output length, d, for SHAKE128 or SHAKE256 used in ECDSA MUST be
   256 or 512 bits, respectively.

   Conforming CA implementations that generate ECDSA with SHAKE
   signatures in certificates or CRLs SHOULD generate such signatures
   with a deterministically generated, non-random 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.







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5.2.  Public Keys

   Certificates conforming to [RFC5280] can convey a public key for any
   public key algorithm.  The certificate indicates the public key
   algorithm through an algorithm identifier.  This algorithm identifier
   is an OID and optionally associated parameters.  The conventions and
   encoding for RSASSA-PSS and ECDSA public keys algorithm identifiers
   are as specified in Section 2.3.1 and 2.3.5 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 subject 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 with
   SHAKEs, the AlgorithmIdentifiers for RSASSA-PSS defined in Section 4
   SHOULD be used as the algorithm field in the SubjectPublicKeyInfo
   sequence [RFC5280].  Conforming client implementations that process
   RSASSA-PSS with SHAKE public keys when processing certificates and
   CRLs MUST recognize the corresponding OIDs.

   Conforming CA implementations MUST specify the X.509 public key
   algorithm explicitly by using the OIDs specified in Section 4 when
   encoding ECDSA with SHAKE public keys in certificates and CRLs.
   Conforming client implementations that process ECDSA with SHAKE
   public keys when processing certificates and CRLs MUST recognize the
   corresponding OIDs.

   The identifier parameters, as explained in Section 4, MUST be absent.

6.  IANA Considerations

   One object identifier for the ASN.1 module in Appendix A is requested
   for the SMI Security for PKIX Module Identifiers (1.3.6.1.5.5.7.0)
   registry:

        +---------+--------------------------+--------------------+
        | Decimal |       Description        |     References     |
        +---------+--------------------------+--------------------+
        |   TBD   | id-mod-pkix1-shakes-2019 | [EDNOTE: THIS RFC] |
        +---------+--------------------------+--------------------+

   IANA is requested to update the SMI Security for PKIX Algorithms
   [SMI-PKIX] (1.3.6.1.5.5.7.6) registry with four additional entries:






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         +---------+------------------------+--------------------+
         | Decimal |      Description       |     References     |
         +---------+------------------------+--------------------+
         |   TBD1  | id-RSASSA-PSS-SHAKE128 | [EDNOTE: THIS RFC] |
         |   TBD2  | id-RSASSA-PSS-SHAKE256 | [EDNOTE: THIS RFC] |
         |   TBD3  | id-ecdsa-with-shake128 | [EDNOTE: THIS RFC] |
         |   TBD4  | id-ecdsa-with-shake256 | [EDNOTE: THIS RFC] |
         +---------+------------------------+--------------------+

   IANA is also requested to update the Hash Function Textual Names
   Registry [Hash-Texts] with two additional entries for SHAKE128 and
   SHAKE256:

   +--------------------+-------------------------+--------------------+
   | Hash Function Name |           OID           |     Reference      |
   +--------------------+-------------------------+--------------------+
   |      shake128      | 2.16.840.1.101.3.4.2.11 | [EDNOTE: THIS RFC] |
   |      shake256      | 2.16.840.1.101.3.4.2.12 | [EDNOTE: THIS RFC] |
   +--------------------+-------------------------+--------------------+

7.  Security Considerations

   This document updates [RFC3279].  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 output length of 256-bits offers 128-bits of collision
   and preimage resistance.  Thus, SHAKE128 OIDs in this specification
   are RECOMMENDED with 2048 (112-bit security) or 3072-bit (128-bit
   security) RSA modulus or curves with group order of 256-bits (128-bit
   security).  SHAKE256 with 512-bits 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 521-bits (256-bit security).
   Note that we recommended 4096-bit RSA because we would need 15360-bit
   modulus for 256-bits of security which is impractical for today's
   technology.

8.  Acknowledgements

   We would like to thank Sean Turner, Jim Schaad and Eric Rescorla for
   their valuable contributions to this document.




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   The authors would like to thank Russ Housley for his guidance and
   very valuable contributions with the ASN.1 module.

9.  References

9.1.  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>.

   [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>.

   [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>.

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

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

   [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>.







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   [SHA3]     National Institute of Standards and Technology (NIST),
              "SHA-3 Standard - Permutation-Based Hash and Extendable-
              Output Functions FIPS PUB 202", August 2015,
              <https://www.nist.gov/publications/sha-3-standard-
              permutation-based-hash-and-extendable-output-functions>.

9.2.  Informative References

   [Hash-Texts]
              IANA, "Hash Function Textual Names", July 2017,
              <https://www.iana.org/assignments/hash-function-text-
              names/hash-function-text-names.xhtml>.

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

   [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>.

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

   [SMI-PKIX]
              IANA, "SMI Security for PKIX Algorithms", March 2019,
              <https://www.iana.org/assignments/smi-numbers/
              smi-numbers.xhtml#smi-numbers-1.3.6.1.5.5.7.6>.

   [SP800-107]
              National Institute of Standards and Technology (NIST),
              "SP800-107: Recommendation for Applications Using Approved
              Hash Algorithms", May 2014,
              <https://csrc.nist.gov/csrc/media/publications/sp/800-107/
              rev-1/final/documents/draft_revised_sp800-107.pdf>.

   [SP800-78-4]
              National Institute of Standards and Technology (NIST),
              "SP800-78-4: Cryptographic Algorithms and Key Sizes for
              Personal Identity Verification", May 2014,
              <https://csrc.nist.gov/csrc/media/publications/sp/800-
              78/4/final/documents/sp800_78-4_revised_draft.pdf>.






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

Appendix A.  ASN.1 module

   This appendix includes the ASN.1 module for SHAKEs in X.509.  This
   module does not come from any existing RFC.

    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(TBD) }

    DEFINITIONS EXPLICIT TAGS ::=

    BEGIN

    -- EXPORTS ALL;

    IMPORTS

    -- FROM [RFC5912]

    PUBLIC-KEY, SIGNATURE-ALGORITHM, DIGEST-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) }

    -- FROM [RFC5912]

    RSAPublicKey, rsaEncryption, pk-rsa, pk-ec,
    CURVE, id-ecPublicKey, ECPoint, ECParameters, ECDSA-Sig-Value
    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) }
   ;

    --
    -- Message Digest Algorithms (mda-)
    --
    DigestAlgorithms DIGEST-ALGORITHM ::= {
      -- This expands DigestAlgorithms from [RFC5912]
      mda-shake128   |
      mda-shake256,
      ...
    }



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    --
    -- 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 (pk-) Algorithms
    --
    PublicKeys PUBLIC-KEY ::= {
      -- This expands PublicKeys from [RFC5912]
      pk-rsaSSA-PSS-SHAKE128 |
      pk-rsaSSA-PSS-SHAKE256,
      ...
    }

    -- The hashAlgorithm is mda-shake128
    -- The maskGenAlgorithm is id-shake128
    -- Mask Gen Algorithm is SHAKE128 with output length
    -- (8*ceil((n-1)/8) - 264) bits, where n is the RSA
    -- modulus in bits.
    -- The saltLength is 32. The trailerField is 1.
    pk-rsaSSA-PSS-SHAKE128 PUBLIC-KEY ::= {
      IDENTIFIER id-RSASSA-PSS-SHAKE128
      KEY RSAPublicKey
      PARAMS ARE absent
      -- Private key format not in this module --
      CERT-KEY-USAGE { nonRepudiation, digitalSignature,
                       keyCertSign, cRLSign }
    }

    -- The hashAlgorithm is mda-shake256



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    -- The maskGenAlgorithm is id-shake256
    -- Mask Gen Algorithm is SHAKE256 with output length
    -- (8*ceil((n-1)/8) - 520)-bits, where n is the RSA
    -- modulus in bits.
    -- The saltLength is 64. The trailerField is 1.
    pk-rsaSSA-PSS-SHAKE256 PUBLIC-KEY ::= {
      IDENTIFIER id-RSASSA-PSS-SHAKE256
      KEY RSAPublicKey
      PARAMS ARE absent
      -- Private key format not in this module --
      CERT-KEY-USAGE { nonRepudiation, digitalSignature,
                       keyCertSign, cRLSign }
    }

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

    --
    -- SMIME Capabilities (sa-)
    --
    SMimeCaps SMIME-CAPS ::= {
      -- The expands SMimeCaps from [RFC5912]
      sa-rsassapssWithSHAKE128.&smimeCaps |
      sa-rsassapssWithSHAKE256.&smimeCaps |
      sa-ecdsaWithSHAKE128.&smimeCaps |
      sa-ecdsaWithSHAKE256.&smimeCaps,
      ...
    }

    -- RSASSA-PSS with SHAKE128
    sa-rsassapssWithSHAKE128 SIGNATURE-ALGORITHM ::= {
      IDENTIFIER id-RSASSA-PSS-SHAKE128
      PARAMS ARE absent
          -- The hashAlgorithm is mda-shake128
          -- The maskGenAlgorithm is id-shake128
          -- Mask Gen Algorithm is SHAKE128 with output length
          -- (8*ceil((n-1)/8) - 264) bits, where n is the RSA
          -- modulus in bits.
          -- The saltLength is 32. The trailerField is 1



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      HASHES { mda-shake128 }
      PUBLIC-KEYS { pk-rsa | pk-rsaSSA-PSS-SHAKE128 }
      SMIME-CAPS { IDENTIFIED BY id-RSASSA-PSS-SHAKE128 }
    }
    id-RSASSA-PSS-SHAKE128  OBJECT IDENTIFIER  ::=  { iso(1)
            identified-organization(3) dod(6) internet(1)
            security(5) mechanisms(5) pkix(7) algorithms(6)
            TBD1 }

    -- RSASSA-PSS with SHAKE256
    sa-rsassapssWithSHAKE256 SIGNATURE-ALGORITHM ::= {
      IDENTIFIER id-RSASSA-PSS-SHAKE256
      PARAMS ARE absent
          -- The hashAlgorithm is mda-shake256
          -- The maskGenAlgorithm is id-shake256
          -- Mask Gen Algorithm is SHAKE256 with output length
          -- (8*ceil((n-1)/8) - 520)-bits, where n is the
          -- RSA modulus in bits.
          -- The saltLength is 64. The trailerField is 1.
     HASHES { mda-shake256 }
     PUBLIC-KEYS { pk-rsa | pk-rsaSSA-PSS-SHAKE256 }
     SMIME-CAPS { IDENTIFIED BY id-RSASSA-PSS-SHAKE256 }
    }
    id-RSASSA-PSS-SHAKE256  OBJECT IDENTIFIER  ::=  { iso(1)
            identified-organization(3) dod(6) internet(1)
            security(5) mechanisms(5) pkix(7) algorithms(6)
            TBD2 }

    -- ECDSA with SHAKE128
    sa-ecdsaWithSHAKE128 SIGNATURE-ALGORITHM ::= {
      IDENTIFIER id-ecdsa-with-shake128
      VALUE ECDSA-Sig-Value
      PARAMS ARE absent
      HASHES { mda-shake128 }
      PUBLIC-KEYS { pk-ec }
      SMIME-CAPS { IDENTIFIED BY id-ecdsa-with-shake128 }
    }
    id-ecdsa-with-shake128 OBJECT IDENTIFIER  ::=  { iso(1)
            identified-organization(3) dod(6) internet(1)
            security(5) mechanisms(5) pkix(7) algorithms(6)
            TBD3 }

    -- ECDSA with SHAKE256
    sa-ecdsaWithSHAKE256 SIGNATURE-ALGORITHM ::= {
      IDENTIFIER id-ecdsa-with-shake256
      VALUE ECDSA-Sig-Value
      PARAMS ARE absent
      HASHES { mda-shake256 }



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      PUBLIC-KEYS { pk-ec }
      SMIME-CAPS { IDENTIFIED BY id-ecdsa-with-shake256 }
    }
    id-ecdsa-with-shake256 OBJECT IDENTIFIER  ::=  { iso(1)
            identified-organization(3) dod(6) internet(1)
            security(5) mechanisms(5) pkix(7) algorithms(6)
            TBD4 }

    END

Authors' Addresses

   Panos Kampanakis
   Cisco Systems

   Email: pkampana@cisco.com


   Quynh Dang
   NIST
   100 Bureau Drive, Stop 8930
   Gaithersburg, MD  20899-8930
   USA

   Email: quynh.dang@nist.gov


























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