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Versions: 00 01 02 rfc7479                                              
INTERNET-DRAFT                                              S. Moonesamy
Intended Status: Informational
Expires: July 28, 2014                                  January 24, 2014


                Using ED25519 in SSHFP Resource Records
                    draft-moonesamy-sshfp-ed25519-00


Abstract

   The Ed25519 signature algorithm has recently been implemented in
   OpenSSH.  This document updates the IANA "SSHFP RR Types for public
   key algorithms" registry by adding an algorithm number for Ed25519.


Status of this Memo

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

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF), its areas, and its working groups.  Note that
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Copyright and License Notice

   Copyright (c) 2014 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
   (http://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



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   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.















































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1.  Introduction

   The Ed25519 [Ed25519] signature algorithm has recently been
   implemented in OpenSSH.  RFC 4255 [RFC4255] defines a new DNS
   resource record, "SSHFP", which can be used to publish a fingerprint
   of the SSH server public key in the DNS.  This document updates the
   IANA "SSHFP RR Types for public key algorithms" registry by adding an
   algorithm number for Ed25519 [Ed25519].

2.  ED25519 Public Key

   A SSHFP-aware Secure Shell implementation of the the Ed25519
   signature algorithm should support SHA-256 fingerprints [FIPS180-
   4][RFC6594] for verification of the ED25519 public key.  A SSHFP-
   aware Secure Shell implementation which also supports SHA1
   fingerprints [FIPS180-4][RFC6594] must choose a SHA-256 fingerprint
   over a SHA1 fingerprint if both fingerprints are available.  If the
   SHA-256 fingerprint does not match the SSH public key received from
   the SSH server, it is recommended that the public key be rejected
   instead of testing the SHA1 fingerprint.

2.2. ED25519 Public Key with SHA1 Fingerprint

   The SSHFP Resource Record for the ED25519 public key with SHA1
   fingerprint would, for example, be:

      ssh.example.com IN SSHFP [TBD] 1 ( 06a2de9a2d0f034701d67917e49cfc4
                                         5a03c2e61 )


2.2. ED25519 Public Key with SHA-256 Fingerprint

      The SSHFP Resource Record for the ED25519 public key with SHA-256
      fingerprint would, for example, be:

      ssh.example.com IN SSHFP [TBD] 2 ( a87f1b687ac0e57d2a081a2f2826723
                                         34d90ed316d2b818ca9580ea384d924
                                         01 )

   RFC Editor Note: Please replace TBD with the value assigned by IANA.

3.  Security Considerations

   The overall security of using SSHFP for SSH host key verification is
   dependent on the security policies of the SSH host administrator and
   DNS zone administrator (in transferring the fingerprint), detailed
   aspects of how verification is done in the SSH implementation, and in
   the client's diligence in accessing the DNS in a secure manner.



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   Please refer to RFC 4255 [RFC4255] for a discussion of the security
   considerations.


4.  IANA Considerations

   IANA is requested to add the following entry to the "SSHFP RR Types
   for public key algorithms" registry:

      +--------+-------------+------------+
      | Value  | Description |  Reference |
      +--------+-------------+------------+
      |  [TBD] |    ED25519  | [RFCXXXX]  |
      +--------+-------------+------------+

   RFC Editor Note: Please replace TBD with the value assigned by IANA
   and RFCXXXX to refer to this document.

5. Acknowledgements

   Some of the text in this document is from RFC 6594 which was written
   by Ondrej Sury.  The author would like to thank Damien Miller for his
   feedback.

6.  References

6.1.  Normative References

   [RFC4255]  Schlyter, J. and W. Griffin, "Using DNS to Securely
              Publish Secure Shell (SSH) Key Fingerprints", RFC 4255,
              January 2006.

   [RFC6594]  Sury, O., "Use of the SHA-256 Algorithm with RSA, Digital
              Signature Algorithm (DSA), and Elliptic Curve DSA (ECDSA)
              in SSHFP Resource Records", RFC 6594, April 2012.

   [FIPS180-4]  National Institute of Standards and Technology, "Secure
              Hash Standard (SHS)", FIPS PUB 180-4, March 2012,
              <http://csrc.nist.gov/publications/fips/fips180-4/fips180-
              4_final.pdf>.

6.2.  Informative References

   [Ed25519]  <http://ed25519.cr.yp.to/ed25519-20110926.pdf>

Authors' Addresses





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   S. Moonesamy
   76, Ylang Ylang Avenue
   Quatres Bornes
   Mauritius

   Email: sm+ietf@elandsys.com













































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