Internet Engineering Task Force (IETF) S. Turner
Request for Comments: 6162 IECA
Updates: 5959 April 2011
Category: Standards Track
ISSN: 2070-1721
Elliptic Curve Algorithms for Cryptographic Message Syntax (CMS)
Asymmetric Key Package Content Type
Abstract
This document describes conventions for using Elliptic Curve
cryptographic algorithms with SignedData and EnvelopedData to protect
the AsymmetricKeyPackage content type. Specifically, it includes
conventions necessary to implement Elliptic Curve Diffie-Hellman
(ECDH) with EnvelopedData and Elliptic Curve Digital Signature
Algorithm (ECDSA) with SignedData. This document extends RFC 5959.
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 5741.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc6162.
Copyright Notice
Copyright (c) 2011 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.
Turner Standards Track [Page 1]RFC 6162 EC Algorithms for CMS Asymmetric Key Packages April 2011
1. Introduction
[RFC5959] describes conventions necessary to protect the
AsymmetricKeyPackage content type [RFC5958] with Cryptographic
Message Syntax (CMS) protecting the following content types:
SignedData [RFC5652], EnvelopedData [RFC5652], EncryptedData
[RFC5652], AuthenticatedData [RFC5652], and AuthEnvelopedData
[RFC5083]. This document amends [RFC5959] by extending the
algorithms used with SignedData and EnvelopedData to include Elliptic
Curve Digital Signature Algorithm (ECDSA) and Elliptic Curve Diffie-
Hellman (ECDH), respectively. Familiarity with [RFC5959] and
[RFC5753] is assumed.
This document does not define any new algorithms; instead, it refers
to previously defined algorithms.
1.1 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
[RFC2119].
2. AsymmetricKeyPackage
As noted in Asymmetric Key Packages [RFC5958], CMS can be used to
protect the AsymmetricKeyPackage. The following provides guidance
for SignedData [RFC5652] and EnvelopedData [RFC5652] when used with
Elliptic Curve algorithms.
2.1. SignedData
If an implementation supports SignedData, then it MAY support ECDSA
[RFC6090][RFC5753].
2.2. EnvelopedData
When key agreement is used, standard (as opposed to cofactor) ECDH
[RFC6090][RFC5753] MAY be supported.
3. Public Key Sizes
The easiest way to implement SignedData and EnvelopedData is with
public key certificates [RFC5280][RFC5480]. If an implementation
supports ECDSA or ECDH, then it MUST support keys on the P-256 curve.
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RFC 6162 EC Algorithms for CMS Asymmetric Key Packages April 2011
4. Security Considerations
The security considerations from [RFC5280], [RFC5480], [RFC5652],
[RFC5753], [RFC5959], and [RFC6090] apply.
5. References
5.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[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, May 2008.
[RFC5480] Turner, S., Brown, D., Yiu, K., Housley, R., and T. Polk,
"Elliptic Curve Cryptography Subject Public Key
Information", RFC 5480, March 2009.
[RFC5652] Housley, R., "Cryptographic Message Syntax (CMS)", STD 70,
RFC 5652, September 2009.
[RFC5753] Turner, S. and D. Brown, "Use of Elliptic Curve
Cryptography (ECC) Algorithms in Cryptographic Message
Syntax (CMS)", RFC 5753, January 2010.
[RFC5958] Turner, S., "Asymmetric Key Packages", RFC 5958, August
2010.
[RFC5959] Turner, S., "Algorithms for Asymmetric Key Package Content
Type", RFC 5959, August 2010.
[RFC6090] McGrew, D., Igoe, K., and M. Salter, "Fundamental Elliptic
Curve Cryptography Algorithms", RFC 6090, February 2011.
5.2. Informative Reference
[RFC5083] Housley, R., "Cryptographic Message Syntax (CMS)
Authenticated-Enveloped-Data Content Type", RFC 5083,
November 2007.
Turner Standards Track [Page 3]RFC 6162 EC Algorithms for CMS Asymmetric Key Packages April 2011
Author's Address
Sean Turner
IECA, Inc.
3057 Nutley Street, Suite 106
Fairfax, VA 22031
USA
EMail: turners@ieca.com
Turner Standards Track [Page 4]
