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
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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
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.
[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: turners@ieca.com