Internet DRAFT - draft-moonesamy-sshfp-ed25519
draft-moonesamy-sshfp-ed25519
INTERNET-DRAFT S. Moonesamy
Intended Status: Informational
Expires: March 4, 2015 August 31, 2014
Using ED25519 in SSHFP Resource Records
draft-moonesamy-sshfp-ed25519-02
Abstract
The Ed25519 signature algorithm has 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.
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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
to this document. Code Components extracted from this document must
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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, specifically Ed25519-SHA-
512, has been implemented in OpenSSH. RFC 4255 [RFC4255] defines a
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 with SHA-256 Fingerprint
The SSHFP Resource Record for the ED25519 public key with SHA-256
fingerprint [FIPS180-4] 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.]
The following body of the public key file was used as input to
generate the above fingerprint:
ssh-ed25519
AAAAC3NzaC1lZDI1NTE5AAAAIGPKSUTyz1HwHReFVvD5obVsALAgJRNarH4TRpNePnAS
The opaque octet string output produced is placed as-is in the RDATA
fingerprint field.
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.
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:
+--------+-------------+------------+
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| 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 was written by Ondrej Sury. The
author would like to thank Damien Miller, Yoav Nir, and Paul Wouters
for their feedback. Rene Struik provided advice about the usage of
Ed25519. Stephen Farrell, as Security Area Director, reviewed the
code point request.
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.
6.2. Informative References
[Ed25519] Bernstein, D. J., Lange T., Schwabe P., Yang B-Y., High-
Speed High-Security Signatures, Journal of Cryptographic
Engineering, Vol. 2, September 26, 2011
[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>.
Appendix A: Changes
[RFC Editor Note: Please remove this appendix]
A.1 Changes since version 00
o Text about usage policy removed from Section 2
o SHA-1 Fingerprint removed
A.2 Changes since version 01
o Appendix B lists the implementation status of the Ed25519
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signature algorithm.
o Added an example in Section 2 of the public key file used to
generate the fingerprint.
Appendix B: Implementation Status
[RFC Editor Note: Please remove this appendix]
This section records the status of known implementations of the
signature algorithm referenced by this specification at the time of
posting of this Internet-Draft.
The Ed25519 signature algorithm, specifically Ed25519-SHA-512, has been
implemented in OpenSSH (http://www.openssh.org) and it is featured in
production version (http://www.openssh.com/txt/release-6.5). The
software is distributed under a BSD license.
The Ed25519 signature algorithm has also been implemented in Tera Term
(http://sourceforge.jp/ticket/browse.php?group_id=1412&tid=33263). The
software is distributed under a BSD license.
Authors' Addresses
S. Moonesamy
76, Ylang Ylang Avenue
Quatres Bornes
Mauritius
Email: sm+ietf@elandsys.com
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