Network Working Group                                          S. Turner
Internet-Draft                                                      IECA
Updates: 5959 (once approved)                          December 22, 2010
Intended status: Standards Track
Expires: June 22, 2011

    Elliptic Curve Algorithms for Cryptographic Message Syntax (CMS)
                  Asymmetric Key Package Content Type


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

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   This Internet-Draft will expire on June 22, 2010.

Copyright Notice

   Copyright (c) 2010 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
   ( in effect on the date of
   publication of this document.  Please review these documents

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   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.

1.  Introduction

   [RFC5959] describes conventions necessary to protect the
   AsymmetricKeyPackage content type [RFC5958] with Cryptographic
   Message Syntax (CMS) protecting 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",
   "OPTIONAL" in this document are to be interpreted as described in

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

2.2.  EnvelopedData

   When key agreement is used, standard (as opposed to co-factor) ECDH
   [I-D.mcgrew-fundamental-ecc] MAY be supported.

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3.  Public Key Sizes

   The easiest way to implement the 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.

4.  Security Considerations

   The security considerations from [RFC5280], [RFC5480], [RFC5652],
   [RFC5753], [RFC5959], and [I-D.mcgrew-fundamental-ecc] apply.

5.  IANA Considerations

   None.   Please remove this section prior to publication as an RFC.

6.  Normative References

6.1.  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)", 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] Turners, S., "Asymmetric Key Packages", RFC 5958, August

   [RFC5959] Turners, S., "Asymmetric Key Packages", RFC 5959, August

   [I-D.mcgrew-fundamental-ecc] McGrew, D., Igoe, E., and M. Salter,
             "Fundamental Elliptic Curve Cryptography Algorithms",
             draft-mcgrew-fundamental-ecc-04.txt, work-in-progress.

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6.2.  Informative References

   [RFC5083] Housley, R., "Cryptographic Message Syntax (CMS)
             Authenticated-Enveloped-Data Content Type", RFC 5083,
             November 2007.

Authors' Addresses

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


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