RFC6162

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.

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.

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.

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.

SignedData

If an implementation supports SignedData, then it MAY support ECDSA RFC6090RFC5753.

EnvelopedData

When key agreement is used, standard (as opposed to cofactor) ECDH RFC6090RFC5753 MAY be supported.

Public Key Sizes

The easiest way to implement SignedData and EnvelopedData is with public key certificates RFC5280RFC5480. If an implementation supports ECDSA or ECDH, then it MUST support keys on the P-256 curve.

Security Considerations

The security considerations from RFC5280, RFC5480, RFC5652, RFC5753, RFC5959, and RFC6090 apply.

References

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.

Informative Reference

RFC5083 Housley, R., "Cryptographic Message Syntax (CMS)

          Authenticated-Enveloped-Data Content Type", RFC 5083,
          November 2007.

Author's Address

Sean Turner IECA, Inc. 3057 Nutley Street, Suite 106 Fairfax, VA 22031 USA

EMail: [email protected]