[Docs] [txt|pdf] [Tracker] [Email] [Diff1] [Diff2] [Nits]

Versions: 00 01 02 draft-ietf-curdle-ssh-ed25519

Network Working Group                                          B. Harris
Internet-Draft                                            August 1, 2015
Intended status: Informational
Expires: February 2, 2016


    Ed25519 public key algorithm for the Secure Shell (SSH) protocol
                       draft-bjh21-ssh-ed25519-02

Abstract

   This document describes the use of the Ed25519 digital signature
   algorithm in the Secure Shell (SSH) protocol.

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 http://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 February 2, 2016.

Copyright Notice

   Copyright (c) 2015 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
   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.






Harris                  Expires February 2, 2016                [Page 1]


Internet-Draft               Ed25519 for SSH                 August 2015


1.  Introduction

   Secure Shell (SSH) [RFC4251] is a secure remote-login protocol.  It
   provides for an extensible variety of public key algorithms for
   identifying servers and users to one another.  Ed25519
   [I-D.josefsson-eddsa-ed25519] is a digital signature system.
   OpenSSH 6.5 [OpenSSH-6.5] introduced support for using Ed25519 for
   server and user authentication.  Compatible support for Ed25519 has
   since been added to other SSH implementations.

   This document describes the method implemented by OpenSSH and others,
   and formalizes its use of the name "ssh-ed25519".

   Comments on this draft are welcomed and should be sent to the author.

2.  Conventions Used in This Document

   The descriptions of key and signature formats use the notation
   introduced in [RFC4251], Section 3 and the string data type from
   [RFC4251], Section 5.

3.  Public Key Algorithm

   This document describes a public key algorithm for use with SSH in
   accordance with [RFC4253], Section 6.6.  The name of the algorithm is
   "ssh-ed25519".  This algorithm only supports signing and not
   encryption.

4.  Public Key Format

   The "ssh-ed25519" key format has the following encoding:

      string    "ssh-ed25519"
      string    key

   Here 'key' is the 32-octet public key described by
   [I-D.josefsson-eddsa-ed25519], Section 5.5.

5.  Signature Algorithm

   Signatures are generated according to the procedure in
   [I-D.josefsson-eddsa-ed25519], Section 5.6.

6.  Signature format

   The corresponding signature format is:





Harris                  Expires February 2, 2016                [Page 2]


Internet-Draft               Ed25519 for SSH                 August 2015


      string    "ssh-ed25519"
      string    signature

   Here 'signature' is the 64-octet signature produced in accordance
   with [I-D.josefsson-eddsa-ed25519], Section 5.6.

7.  Verification Algorithm

   Signatures are verified according to the procedure in
   [I-D.josefsson-eddsa-ed25519], Section 5.7.

8.  SSHFP DNS resource records

   The generation of SSHFP resource records for "ssh-ed25519" keys is
   described in [RFC7479].

9.  IANA Considerations

   IANA is requested to assign the Public Key Algorithm name
   "ssh-ed25519" in accordance with [RFC4250], Section 4.6.2:

                    Public Key Algorithm Name Reference
                    ------------------------- ---------
                    ssh-ed25519               [RFCXXXX]

   [TO BE REMOVED: This registration should take place at the following
   location: <http://www.iana.org/assignments/ssh-parameters/ssh-
   parameters.xhtml#ssh-parameters-19>]

10.  Security Considerations

   The security considerations in [RFC4251], Section 9 apply to all SSH
   implementations, including those using Ed25519.

   The security considerations in [I-D.josefsson-eddsa-ed25519],
   Section 9 apply to all uses of Ed25519, including those in SSH.

11.  Acknowledgements

   The OpenSSH implementation of Ed25519 in SSH was written by Markus
   Friedl.

12.  References








Harris                  Expires February 2, 2016                [Page 3]


Internet-Draft               Ed25519 for SSH                 August 2015


12.1.  Normative References

   [RFC4250]  Lehtinen, S. and C. Lonvick, Ed., "The Secure Shell (SSH)
              Protocol Assigned Numbers", RFC 4250,
              DOI 10.17487/RFC4250, January 2006,
              <http://www.rfc-editor.org/info/rfc4250>.

   [RFC4251]  Ylonen, T. and C. Lonvick, Ed., "The Secure Shell (SSH)
              Protocol Architecture", RFC 4251, DOI 10.17487/RFC4251,
              January 2006, <http://www.rfc-editor.org/info/rfc4251>.

   [RFC4253]  Ylonen, T. and C. Lonvick, Ed., "The Secure Shell (SSH)
              Transport Layer Protocol", RFC 4253, DOI 10.17487/RFC4253,
              January 2006, <http://www.rfc-editor.org/info/rfc4253>.

   [I-D.josefsson-eddsa-ed25519]
              Josefsson, S. and N. Moller, "EdDSA and Ed25519", draft-
              josefsson-eddsa-ed25519-03 (work in progress), May 2015.

12.2.  Informative References

   [RFC7479]  Moonesamy, S., "Using Ed25519 in SSHFP Resource Records",
              RFC 7479, DOI 10.17487/RFC7479, March 2015,
              <http://www.rfc-editor.org/info/rfc7479>.

   [OpenSSH-6.5]
              Friedl, M., Provos, N., de Raadt, T., Steves, K., Miller,
              D., Tucker, D., McIntyre, J., Rice, T., and B. Lindstrom,
              "[OpenSSH 6.5 release notes]", January 2014,
              <http://www.openssh.com/txt/release-6.5>.

Author's Address

   Ben Harris
   2A Eachard Road
   CAMBRIDGE  CB3 0HY
   UNITED KINGDOM

   Email: bjh21@bjh21.me.uk












Harris                  Expires February 2, 2016                [Page 4]


Html markup produced by rfcmarkup 1.124, available from https://tools.ietf.org/tools/rfcmarkup/