draft-ietf-dnsext-dnssec-algo-signal-02.txt		draft-ietf-dnsext-dnssec-algo-signal-03.txt
	DNS Extensions Working Group S. Crocker		DNS Extensions Working Group S. Crocker
	Internet-Draft Shinkuro Inc.		Internet-Draft Shinkuro Inc.
	Intended status: Standards Track S. Rose		Intended status: Standards Track S. Rose
	Expires: January 7, 2012 NIST		Expires: July 6, 2012 NIST
	July 6, 2011		January 3, 2012
	Signaling Cryptographic Algorithm Understanding in DNSSEC		Signaling Cryptographic Algorithm Understanding in DNSSEC
	draft-ietf-dnsext-dnssec-algo-signal-02		draft-ietf-dnsext-dnssec-algo-signal-03
	Abstract		Abstract
	The DNS Security Extensions (DNSSEC) were developed to provide origin		The DNS Security Extensions (DNSSEC) were developed to provide origin
	authentication and integrity protection for DNS data by using digital		authentication and integrity protection for DNS data by using digital
	signatures. These digital signatures can be generated using		signatures. These digital signatures can be generated using
	different algorithms. This draft sets out to specify a way for		different algorithms. This draft sets out to specify a way for
	validating end-system resolvers to signal to a server which		validating end-system resolvers to signal to a server which
	cryptographic algorithms they support.		cryptographic algorithms they support.
	skipping to change at page 1, line 42		skipping to change at page 1, line 42
	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 January 7, 2012.		This Internet-Draft will expire on July 6, 2012.
	Copyright Notice		Copyright Notice
	Copyright (c) 2011 IETF Trust and the persons identified as the		Copyright (c) 2012 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		Table of Contents
	1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3		1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
	2. Signaling DNSSEC Algorithm Understood (DAU) Using EDNS . . . . 3		2. Signaling DNSSEC Algorithm Understood (DAU) Using EDNS . . . . 3
	3. Client Considerations . . . . . . . . . . . . . . . . . . . . . 4		3. Client Considerations . . . . . . . . . . . . . . . . . . . . . 4
	3.1. Stub Resolvers . . . . . . . . . . . . . . . . . . . . . . 5		3.1. Stub Resolvers . . . . . . . . . . . . . . . . . . . . . . 4
	3.2. Validating Stub Resolvers . . . . . . . . . . . . . . . . . 5		3.2. Validating Stub Resolvers . . . . . . . . . . . . . . . . . 5
	3.3. Non-Validating Stub Resolvers . . . . . . . . . . . . . . . 5		3.3. Non-Validating Stub Resolvers . . . . . . . . . . . . . . . 5
	3.4. Recursive Resolvers . . . . . . . . . . . . . . . . . . . . 5		3.4. Recursive Resolvers . . . . . . . . . . . . . . . . . . . . 5
	3.4.1. Validating Recursive Resolvers . . . . . . . . . . . . 5		3.4.1. Validating Recursive Resolvers . . . . . . . . . . . . 5
	3.4.2. Non-validating Recursive Resolvers . . . . . . . . . . 6		3.4.2. Non-validating Recursive Resolvers . . . . . . . . . . 5
	4. Intermediate System Considerations . . . . . . . . . . . . . . 6		4. Intermediate System Considerations . . . . . . . . . . . . . . 6
	5. Server Considerations . . . . . . . . . . . . . . . . . . . . . 6		5. Server Considerations . . . . . . . . . . . . . . . . . . . . . 6
	6. Traffic Analysis Considerations . . . . . . . . . . . . . . . . 6		6. Traffic Analysis Considerations . . . . . . . . . . . . . . . . 6
	7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 7		7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 6
	8. Security Considerations . . . . . . . . . . . . . . . . . . . . 7		8. Security Considerations . . . . . . . . . . . . . . . . . . . . 7
	9. Normative References . . . . . . . . . . . . . . . . . . . . . 7		9. Normative References . . . . . . . . . . . . . . . . . . . . . 7
	1. Introduction		1. Introduction
	The DNS Security Extensions (DNSSEC) [RFC4033], [RFC4034] and		The DNS Security Extensions (DNSSEC) [RFC4033], [RFC4034] and
	[RFC4035] were developed to provide origin authentication and		[RFC4035] were developed to provide origin authentication and
	integrity protection for DNS data by using digital signatures. Each		integrity protection for DNS data by using digital signatures. Each
	digital signature RR (RRSIG) contains an algorithm code number.		digital signature RR (RRSIG) contains an algorithm code number.
	These algorithm codes tells validators which cryptographic algorithm		These algorithm codes tells validators which cryptographic algorithm
	was used to generate the digital signature. Authentication across		was used to generate the digital signature.
	delegation boundaries is maintained by storing a hash of a subzone's
	key in the parent zone stored in a Delegation Signer (DS) RR. These
	DS RR's contain a second code number to identify the hash algorithm
	used to construct the DS RR.
	This draft sets out to specify a way for validating end-system		This draft sets out to specify a way for validating end-system
	resolvers to tell a server which cryptographic and/or hash algorithms		resolvers to tell a server which cryptographic algorithms they
	they support in a DNS query. This is done using the EDNS attribute		support in a DNS query. This is done using the EDNS attribute values
	values in the OPT meta-RR [RFC2671].		in the OPT meta-RR [RFC2671].
	This proposed EDNS option serves to measure the acceptance and use of		This proposed EDNS option serves to measure the acceptance and use of
	new digital signing and hash algorithms. This algorithm signaling		new digital signing algorithms. This algorithm signaling option can
	option can be used by zone administrators as a gauge to measure the		be used by zone administrators as a gauge to measure the successful
	successful deployment of code that implements a newly deployed		deployment of code that implements a newly deployed digital signature
	digital signature or hash algorithm used with DNSSEC. A zone		algorithm used with DNSSEC. A zone administrator may be able to
	administrator may be able to determine when to stop serving the old		determine when to stop serving the old algorithm when the server sees
	algorithm when the server sees that a significant number of its		that a significant number of its clients signal that they are able to
	clients signal that they are able to accept the new algorithm. Note		accept the new algorithm. Note that this survey may be conducted
	that this survey may be conducted over the period of years before a		over the period of years before a tipping point is seen.
	tipping point is seen.
	This draft does not seek to include another process for including new		This draft does not seek to include another process for including new
	algorithms for use with DNSSEC (see . It also does not address the		algorithms for use with DNSSEC (see . It also does not address the
	question of which algorithms are to be included in any official list		question of which algorithms are to be included in any official list
	of mandatory or recommended cryptographic algorithms for use with		of mandatory or recommended cryptographic algorithms for use with
	DNSSEC. Rather, this document specifies a means by which a client		DNSSEC. Rather, this document specifies a means by which a client
	query can signal a set of algorithms it implements.		query can signal a set of algorithms it implements.
	2. Signaling DNSSEC Algorithm Understood (DAU) Using EDNS		2. Signaling DNSSEC Algorithm Understood (DAU) Using EDNS
	The ENDS0 specification outlined in [RFC2671] defines a way to		The ENDS0 specification outlined in [RFC2671] defines a way to
	include new options using a standardized mechanism. These options		include new options using a standardized mechanism. These options
	are contained in the RDATA of the OPT meta-RR. This document defines		are contained in the RDATA of the OPT meta-RR. This document defines
	a new EDNS0 option for a client to signal which algorithms the client		a new EDNS0 option for a client to signal which algorithms the client
	supports.		supports.
	The figure below shows how the signaling attribute is defined in the		The figure below shows how the digital signature signaling attribute
	RDATA of the OPT RR specified in [RFC2671]:		is defined in the RDATA of the OPT RR specified in [RFC2671]:
	0 8 16		0 8 16
	+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+		+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
	| OPTION-CODE (TBD) |		| OPTION-CODE (TBD) |
	+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+		+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
	| DIGITAL-SIG-LIST-LENGTH |		| DIGITAL-SIG-LIST-LENGTH |
	+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+		+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
	| ALG-CODE | ... \		| ALG-CODE | ... \
	+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+		+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
	| DS-HASH-LIST-LENGTH |
	+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
	| HASH-CODE | ... \
	+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
	OPTION-CODE is the code for the DNSSEC Algorithm Understood (DAU)		OPTION-CODE is the code for the DNSSEC Algorithm Understood (DAU)
	option. Its value is fixed at TBD.		option. Its value is fixed at TBD.
	DIGITAL-SIG-LIST-LENGTH is the length of the list of digital		DIGITAL-SIG-LIST-LENGTH is the length of the list of digital
	signature algorithms in octets. DNSSEC algorithm codes are 1 octet		signature algorithms in octets. DNSSEC algorithm codes are 1 octet
	long so this value is the number of octets.		long so this value is the number of octets.
	ALG-CODE is the list of assigned values of DNSSEC zone signing		ALG-CODE is the list of assigned values of DNSSEC zone signing
	algorithms that the client indicates as understood. The values		algorithms that the client indicates as understood. The values
	SHOULD be in descending order of preference, with the most preferred		SHOULD be in descending order of preference, with the most preferred
	algorithm first. For example, if a validating client implements RSA/		algorithm first. For example, if a validating client implements RSA/
	SHA-1, RSA/SHA-256 and prefers the latter, the value of ALG-CODE		SHA-1, RSA/SHA-256 and prefers the latter, the value of ALG-CODE
	would be: 8 (RSA/SHA-256), 5 (RSA/SHA-1).		would be: 8 (RSA/SHA-256), 5 (RSA/SHA-1).
	DS-HASH-LIST-LENGTH is the length of the list of hash algorithms in
	octets. DNSSEC DS hash codes are 1 octet long so this value is the
	number of octets.
	HASH-CODE is the list of assigned values of DNSSEC DS hash algorithms
	that the client indicates as understood. Like the ALG-CODE above,
	the values SHOULD be in descending order of preference, with the most
	preferred algorithm first.
	3. Client Considerations		3. Client Considerations
	A validating end-system resolver sets the DAU option in the OPT		A validating end-system resolver sets the DAU option in the OPT
	meta-RR when sending a query. The validating end-system resolver		meta-RR when sending a query. The validating end-system resolver
	sets the value(s) in the order of preference, with the most preferred		sets the value(s) in the order of preference, with the most preferred
	algorithm(s) first as described in section 2. The end-system		algorithm(s) first as described in section 2. The end-system
	resolver SHOULD also set the DNSSEC-OK bit [RFC4035] to indicate that		resolver SHOULD also set the DNSSEC-OK bit [RFC4035] to indicate that
	it wishes to receive DNSSEC RRs in the response.		it wishes to receive DNSSEC RRs in the response.
	Note that the PRIVATEDNS (253) and/or the PRIVATEOID (254) codes		Note that the PRIVATEDNS (253) and/or the PRIVATEOID (254) codes
End of changes. 13 change blocks.
	40 lines changed or deleted		22 lines changed or added
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