Internet Engineering Task Force (IETF)                         S. Turner
Request for Comments: 6161                                          IECA
Updates: 6033                                                 April 2011
Category: Standards Track
ISSN: 2070-1721


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

Abstract

  This document describes the conventions for using several Elliptic
  Curve cryptographic algorithms with the Cryptographic Message Syntax
  (CMS) encrypted key package 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 6033.

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/rfc6161.

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.




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RFC 6161      EC Algorithms for CMS Encrypted Key Packages    April 2011


1.  Introduction

  This document describes the conventions for using Elliptic Curve
  cryptographic algorithms with the Cryptographic Message Syntax (CMS)
  encrypted key package content type [RFC6032].  Specifically, it
  includes conventions necessary to implement the following CMS content
  types: EnvelopedData [RFC5652] and SignedData [RFC5652].  This
  document amends [RFC6033].  Familiarity with [RFC6033] 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.  EnvelopedData

  When key agreement is used, standard (as opposed to cofactor) ECDH
  [RFC6090][RFC5753] MAY be supported.

3.  SignedData

  If an implementation encapsulates EncryptedKeyPackage with SignedData
  [RFC5652], then it MAY support the signature scheme ECDSA
  [RFC6090][RFC5753].

4.  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.

5.  Security Considerations

  The security considerations from [RFC5280], [RFC5480], [RFC5652],
  [RFC5753], [RFC6033], and [RFC6090] apply.

6.  Normative References

  [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
             Requirement Levels", BCP 14, RFC 2119, March 1997.





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RFC 6161      EC Algorithms for CMS Encrypted Key Packages    April 2011


  [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.

  [RFC6032]  Turner, S. and R. Housley, "Cryptographic Message Syntax
             (CMS) Encrypted Key Package Content Type", RFC 6032,
             December 2010.

  [RFC6033]  Turner, S., "Algorithms for Cryptographic Message Syntax
             (CMS) Encrypted Key Package Content Type", RFC 6033,
             December 2010.

  [RFC6090]  McGrew, D., Igoe, K., and M. Salter, "Fundamental Elliptic
             Curve Cryptography Algorithms", RFC 6090, February 2011.

Author's Address

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

  EMail: [email protected]















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