



Internet Engineering Task Force (IETF)                      R. Moskowitz
Request for Comments: 9373                                HTT Consulting
Category: Standards Track                                     T. Kivinen
ISSN: 2070-1721                                                         
                                                           M. Richardson
                                                               Sandelman
                                                              March 2023


                        EdDSA Value for IPSECKEY

Abstract

   This document assigns a value for Edwards-Curve Digital Signature
   Algorithm (EdDSA) Public Keys to the "IPSECKEY Resource Record
   Parameters" registry.

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/rfc9373.

Copyright Notice

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

   This document is subject to BCP 78 and the IETF Trust's Legal
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   Trust Legal Provisions and are provided without warranty as described
   in the Revised BSD License.

Table of Contents

   1.  Introduction
   2.  IPSECKEY Support for EdDSA
   3.  IANA Considerations
     3.1.  Update to the IANA IPSECKEY Registry
       3.1.1.  Reformat the Algorithm Type Field Registry
       3.1.2.  Add to the Algorithm Type Field Registry
   4.  Security Considerations
   5.  References
     5.1.  Normative References
     5.2.  Informative References
   Appendix A.  IPSECKEY EdDSA Example
   Acknowledgments
   Authors' Addresses

1.  Introduction

   IPSECKEY [RFC4025] is a resource record (RR) for the Domain Name
   System (DNS) that is used to store public keys for use in IP security
   (IPsec) systems.  The IPSECKEY RR relies on the IPSECKEY "Algorithm
   Type Field" registry [IANA-IPSECKEY] to enumerate the permissible
   formats for the public keys.

   This document adds support for Edwards-Curve Digital Security
   Algorithm (EdDSA) public keys in the format defined in [RFC8080] to
   the IPSECKEY RR.

2.  IPSECKEY Support for EdDSA

   When using the EdDSA public key in the IPSECKEY RR, the value 4 is
   used as an algorithm and the public key is formatted as specified in
   "Edwards-Curve Digital Security Algorithm (EdDSA) for DNSSEC"
   (Section 3 of [RFC8080]).

    +=======+=====================+======================+===========+
    | Value | Description         | Format Description   | Reference |
    +=======+=====================+======================+===========+
    | 4     | An EdDSA Public Key | [RFC8080], Section 3 | This RFC  |
    +-------+---------------------+----------------------+-----------+

                                 Table 1

3.  IANA Considerations

3.1.  Update to the IANA IPSECKEY Registry

3.1.1.  Reformat the Algorithm Type Field Registry

   Per this document, IANA has added the "Format Description" field to
   the "Algorithm Type Field" registry of the "IPSECKEY Resource Record
   Parameters" [IANA-IPSECKEY].  In addition, IANA has updated the
   "Description" field in existing entries of that registry to
   explicitly state that they are for "Public" keys:

   +=======+==========================+====================+===========+
   | Value | Description              | Format Description | Reference |
   +=======+==========================+====================+===========+
   | 0     | No Public key            |                    | [RFC4025] |
   |       | is present               |                    |           |
   +-------+--------------------------+--------------------+-----------+
   | 1     | A DSA Public             | [RFC2536],         | [RFC4025] |
   |       | Key                      | Section 2          |           |
   +-------+--------------------------+--------------------+-----------+
   | 2     | An RSA Public            | [RFC3110],         | [RFC4025] |
   |       | Key                      | Section 2          |           |
   +-------+--------------------------+--------------------+-----------+
   | 3     | An ECDSA                 | [RFC6605],         | [RFC8005] |
   |       | Public Key               | Section 4          |           |
   +-------+--------------------------+--------------------+-----------+

                                  Table 2

   IANA added a reference to this document to the "Algorithm Type Field"
   registry.

3.1.2.  Add to the Algorithm Type Field Registry

   Further, IANA has made the following addition to the "Algorithm Type
   Field" registry within the "IPSECKEY Resource Record Parameters"
   [IANA-IPSECKEY]:

    +=======+=====================+======================+===========+
    | Value | Description         | Format Description   | Reference |
    +=======+=====================+======================+===========+
    | 4     | An EdDSA Public Key | [RFC8080], Section 3 | This RFC  |
    +-------+---------------------+----------------------+-----------+

                                 Table 3

4.  Security Considerations

   The security considerations discussed in [RFC4025] apply.  This
   document does not introduce any new security considerations.

5.  References

5.1.  Normative References

   [IANA-IPSECKEY]
              IANA, "IPSECKEY Resource Record Parameters",
              <https://www.iana.org/assignments/ipseckey-rr-parameters>.

   [RFC8080]  Sury, O. and R. Edmonds, "Edwards-Curve Digital Security
              Algorithm (EdDSA) for DNSSEC", RFC 8080,
              DOI 10.17487/RFC8080, February 2017,
              <https://www.rfc-editor.org/info/rfc8080>.

5.2.  Informative References

   [RFC2536]  Eastlake 3rd, D., "DSA KEYs and SIGs in the Domain Name
              System (DNS)", RFC 2536, DOI 10.17487/RFC2536, March 1999,
              <https://www.rfc-editor.org/info/rfc2536>.

   [RFC3110]  Eastlake 3rd, D., "RSA/SHA-1 SIGs and RSA KEYs in the
              Domain Name System (DNS)", RFC 3110, DOI 10.17487/RFC3110,
              May 2001, <https://www.rfc-editor.org/info/rfc3110>.

   [RFC4025]  Richardson, M., "A Method for Storing IPsec Keying
              Material in DNS", RFC 4025, DOI 10.17487/RFC4025, March
              2005, <https://www.rfc-editor.org/info/rfc4025>.

   [RFC6605]  Hoffman, P. and W.C.A. Wijngaards, "Elliptic Curve Digital
              Signature Algorithm (DSA) for DNSSEC", RFC 6605,
              DOI 10.17487/RFC6605, April 2012,
              <https://www.rfc-editor.org/info/rfc6605>.

   [RFC8005]  Laganier, J., "Host Identity Protocol (HIP) Domain Name
              System (DNS) Extension", RFC 8005, DOI 10.17487/RFC8005,
              October 2016, <https://www.rfc-editor.org/info/rfc8005>.

Appendix A.  IPSECKEY EdDSA Example

   The following is an example of an IPSECKEY RR with no gateway, and an
   EdDSA public key.  It uses the IPSECKEY presentation format which is
   base64.

      foo.example.com. IN IPSECKEY (
            10 0 4 . 3WTXgUvpn1RlCXnm80gGY2LZ/ErUUEZtZ33IDi8yfhM= )


   The associated EdDSA private key (in hex) is as follows:

      c7be71a45cbf87785f639dc4fd1c82637c21b5e02488939976ece32b9268d0b7


Acknowledgments

   Thanks to the Security Area Director, Paul Wouters, for his initial
   review.  Also, thanks to Security Area Director, Roman Danyliw, for
   his final reviews and document shepherding.

Authors' Addresses

   Robert Moskowitz
   HTT Consulting
   Oak Park, MI 48237
   United States of America
   Email: rgm@labs.htt-consult.com


   Tero Kivinen
   Email: kivinen@iki.fi


   Michael C. Richardson
   Sandelman Software Works
   Email: mcr+ietf@sandelman.ca
   URI:   https://www.sandelman.ca/
