< draft-ietf-curdle-cms-ecdh-new-curves-08.txt		draft-ietf-curdle-cms-ecdh-new-curves-09.txt >
	Internet-Draft R. Housley		Internet-Draft R. Housley
	Intended status: Standards Track Vigil Security		Intended status: Standards Track Vigil Security
	Expires: 2 December 2017 2 June 2017		Expires: 4 December 2017 4 June 2017
	Use of the Elliptic Curve Diffie-Hellman Key Agreement Algorithm		Use of the Elliptic Curve Diffie-Hellman Key Agreement Algorithm
	with X25519 and X448 in the Cryptographic Message Syntax (CMS)		with X25519 and X448 in the Cryptographic Message Syntax (CMS)
	<draft-ietf-curdle-cms-ecdh-new-curves-08.txt>		<draft-ietf-curdle-cms-ecdh-new-curves-09.txt>
	Abstract		Abstract
	This document describes the conventions for using Elliptic Curve		This document describes the conventions for using Elliptic Curve
	Diffie-Hellman (ECDH) key agreement algorithm using curve25519 and		Diffie-Hellman (ECDH) key agreement algorithm using curve25519 and
	curve448 in the Cryptographic Message Syntax (CMS).		curve448 in the Cryptographic Message Syntax (CMS).
	Status of This Memo		Status of This Memo
	This Internet-Draft is submitted in full conformance with the		This Internet-Draft is submitted in full conformance with the
	skipping to change at page 1, line 33 ¶		skipping to change at page 1, line 33 ¶
	Internet-Drafts are working documents of the Internet Engineering		Internet-Drafts are working documents of the Internet Engineering
	Task Force (IETF). Note that other groups may also distribute		Task Force (IETF). Note that other groups may also distribute
	working documents as Internet-Drafts. The list of current Internet-		working documents as Internet-Drafts. The list of current Internet-
	Drafts is at http://datatracker.ietf.org/drafts/current/.		Drafts is at http://datatracker.ietf.org/drafts/current/.
	Internet-Drafts are draft documents valid for a maximum of six months		Internet-Drafts are draft documents valid for a maximum of six months
	and may be updated, replaced, or obsoleted by other documents at any		and may be updated, replaced, or obsoleted by other documents at any
	time. It is inappropriate to use Internet-Drafts as reference		time. It is inappropriate to use Internet-Drafts as reference
	material or to cite them other than as "work in progress."		material or to cite them other than as "work in progress."
	This Internet-Draft will expire on 2 December 2017.		This Internet-Draft will expire on 4 December 2017.
	Copyright Notice		Copyright Notice
	Copyright (c) 2017 IETF Trust and the persons identified as the		Copyright (c) 2017 IETF Trust and the persons identified as the
	document authors. All rights reserved.		document authors. All rights reserved.
	This document is subject to BCP 78 and the IETF Trust's Legal		This document is subject to BCP 78 and the IETF Trust's Legal
	Provisions Relating to IETF Documents		Provisions Relating to IETF Documents
	(http://trustee.ietf.org/license-info) in effect on the date of		(http://trustee.ietf.org/license-info) in effect on the date of
	publication of this document. Please review these documents		publication of this document. Please review these documents
	carefully, as they describe your rights and restrictions with respect		carefully, as they describe your rights and restrictions with respect
	to this document. Code Components extracted from this document must		to this document. Code Components extracted from this document must
	include Simplified BSD License text as described in Section 4.e of		include Simplified BSD License text as described in Section 4.e of
	the Trust Legal Provisions and are provided without warranty as		the Trust Legal Provisions and are provided without warranty as
	described in the Simplified BSD License.		described in the Simplified BSD License.
			Table of Contents
			1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 2
			1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 2
			1.2. ASN.1 . . . . . . . . . . . . . . . . . . . . . . . . . . 2
			2. Key Agreement . . . . . . . . . . . . . . . . . . . . . . . . 2
			2.1. ANSI-X9.63-KDF . . . . . . . . . . . . . . . . . . . . . . 5
			2.2. HKDF . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
			3. Enveloped-data Conventions . . . . . . . . . . . . . . . . . . 6
			3.1. EnvelopedData Fields . . . . . . . . . . . . . . . . . . . 6
			3.2. KeyAgreeRecipientInfo Fields . . . . . . . . . . . . . . . 7
			4. Authenticated-data Conventions . . . . . . . . . . . . . . . . 8
			4.1. AuthenticatedData Fields . . . . . . . . . . . . . . . . . 8
			4.2. KeyAgreeRecipientInfo Fields . . . . . . . . . . . . . . . 8
			5. Authenticated-Enveloped-data Conventions . . . . . . . . . . . 8
			5.1. AuthEnvelopedData Fields . . . . . . . . . . . . . . . . . 9
			5.2. KeyAgreeRecipientInfo Fields . . . . . . . . . . . . . . . 9
			6. Certificate Conventions . . . . . . . . . . . . . . . . . . . 9
			7. Key Agreement Algorithm Identifiers . . . . . . . . . . . . . 9
			8. SMIMECapabilities Attribute Conventions . . . . . . . . . . . 10
			9. Security Considerations . . . . . . . . . . . . . . . . . . . 11
			10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12
			11. Normative References . . . . . . . . . . . . . . . . . . . . 12
			12. Informative References . . . . . . . . . . . . . . . . . . . 14
			Appendix: ASN.1 Module . . . . . . . . . . . . . . . . . . . . . . 15
			Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . . 17
			Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 17
	1. Introduction		1. Introduction
	This document describes the conventions for using Elliptic Curve		This document describes the conventions for using Elliptic Curve
	Diffie-Hellman (ECDH) key agreement using curve25519 and curve448		Diffie-Hellman (ECDH) key agreement using curve25519 and curve448
	[CURVES] in the Cryptographic Message Syntax (CMS) [CMS]. Key		[CURVES] in the Cryptographic Message Syntax (CMS) [CMS]. Key
	agreement is supported in three CMS content types: the enveloped-data		agreement is supported in three CMS content types: the enveloped-data
	content type [CMS], authenticated-data content type [CMS], and the		content type [CMS], authenticated-data content type [CMS], and the
	authenticated-enveloped-data content type [AUTHENV].		authenticated-enveloped-data content type [AUTHENV].
	The conventions for using some Elliptic Curve Cryptography (ECC)		The conventions for using some Elliptic Curve Cryptography (ECC)
	skipping to change at page 4, line 45 ¶		skipping to change at page 5, line 27 ¶
	Three values are used as inputs to the HKDF:		Three values are used as inputs to the HKDF:
	1. The shared secret value generated by ECDH, K.		1. The shared secret value generated by ECDH, K.
	2. The length in octets of the keying data to be generated.		2. The length in octets of the keying data to be generated.
	3. The DER-encoded ECC-CMS-SharedInfo structure.		3. The DER-encoded ECC-CMS-SharedInfo structure.
	The ECC-CMS-SharedInfo structure optionally includes the ukm. If the		The ECC-CMS-SharedInfo structure optionally includes the ukm. If the
	ukm is present, the ukm is also used as the HKDF salt. HKDF uses an		ukm is present, the ukm is also used as the HKDF salt. HKDF uses an
	appropriate number of zero octets when no salt is provided.		appropriate number of zero octets when no salt is provided.
	The length of the generated key-encryption key is used two places,		The length of the generated key-encryption key is used in two places,
	once in bits, and once in octets. The ECC-CMS-SharedInfo structure		once in bits, and once in octets. The ECC-CMS-SharedInfo structure
	includes the length of the generated key-encryption key in bits. The		includes the length of the generated key-encryption key in bits. The
	HKDF-Expand function takes an argument for the length of the		HKDF-Expand function takes an argument for the length of the
	generated key-encryption key in octets.		generated key-encryption key in octets.
	In summary, to produce the pairwise key-encryption key, KEK:		In summary, to produce the pairwise key-encryption key, KEK:
	if ukm is provided, then salt = ukm, else salt is not provided		if ukm is provided, then salt = ukm, else salt is not provided
	PRK = HKDF-Extract(salt, K)		PRK = HKDF-Extract(salt, K)
	skipping to change at page 16, line 33 ¶		skipping to change at page 17, line 33 ¶
	IDENTIFIED BY dhSinglePass-stdDH-hkdf-sha384-scheme}		IDENTIFIED BY dhSinglePass-stdDH-hkdf-sha384-scheme}
	cap-kaa-dhSinglePass-stdDH-hkdf-sha512-scheme SMIME-CAPS ::= {		cap-kaa-dhSinglePass-stdDH-hkdf-sha512-scheme SMIME-CAPS ::= {
	TYPE KeyWrapAlgorithm		TYPE KeyWrapAlgorithm
	IDENTIFIED BY dhSinglePass-stdDH-hkdf-sha512-scheme }		IDENTIFIED BY dhSinglePass-stdDH-hkdf-sha512-scheme }
	END		END
	Acknowledgements		Acknowledgements
	Many thanks to Daniel Migault, Eric Rescorla, Jim Schaad, Stefan		Many thanks to Roni Even, Daniel Migault, Eric Rescorla, Jim Schaad,
	Santesson, and Sean Turner for their review and insightful		Stefan Santesson, and Sean Turner for their review and insightful
	suggestions.		suggestions.
	Author's Address		Author's Address
	Russ Housley		Russ Housley
	918 Spring Knoll Drive		918 Spring Knoll Drive
	Herndon, VA 20170		Herndon, VA 20170
	USA		USA
	housley@vigilsec.com		housley@vigilsec.com
End of changes. 6 change blocks.
	6 lines changed or deleted		34 lines changed or added
This html diff was produced by rfcdiff 1.48. The latest version is available from http://tools.ietf.org/tools/rfcdiff/