< draft-york-dnsop-deploying-dnssec-crypto-algs-01.txt		draft-york-dnsop-deploying-dnssec-crypto-algs-02.txt >
	DNSOP Working Group D. York		DNSOP D. York
	Internet-Draft Internet Society		Internet-Draft Internet Society
	Intended status: Informational O. Sury		Intended status: Informational O. Sury
	Expires: January 9, 2017 CZ.NIC		Expires: May 4, 2017 CZ.NIC
	P. Wouters		P. Wouters
	Red Hat		Red Hat
	O. Gudmundsson		O. Gudmundsson
	CloudFlare		CloudFlare
	July 08, 2016		October 31, 2016
	Observations on Deploying New DNSSEC Cryptographic Algorithms		Observations on Deploying New DNSSEC Cryptographic Algorithms
	draft-york-dnsop-deploying-dnssec-crypto-algs-01		draft-york-dnsop-deploying-dnssec-crypto-algs-02
	Abstract		Abstract
	As new cryptographic algorithms are developed for use in DNSSEC		As new cryptographic algorithms are developed for use in DNSSEC
	signing and validation, this document captures the steps needed for		signing and validation, this document captures the steps needed for
	new algorithms to be deployed and enter general usage. The intent is		new algorithms to be deployed and enter general usage. The intent is
	to ensure a common understanding of the typical deployment process		to ensure a common understanding of the typical deployment process
	and potentially identify opportunities for improvement of operations.		and potentially identify opportunities for improvement of operations.
	Status of This Memo		Status of This Memo
	skipping to change at page 1, line 39 ¶		skipping to change at page 1, line 39 ¶
	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 9, 2017.		This Internet-Draft will expire on May 4, 2017.
	Copyright Notice		Copyright Notice
	Copyright (c) 2016 IETF Trust and the persons identified as the		Copyright (c) 2016 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 . . . . . . . . . . . . . . . . . . . . . . . 3
			2. Aspects of Deploying New Algorithms . . . . . . . . . . . . . 3
			2.1. DNS Resolvers Performing Validation . . . . . . . . . . . 4
			2.1.1. Resolvers and Unknown Algorithms . . . . . . . . . . 4
			2.2. Authoritative DNS Servers . . . . . . . . . . . . . . . . 5
			2.3. Signing Software . . . . . . . . . . . . . . . . . . . . 5
			2.4. Registries . . . . . . . . . . . . . . . . . . . . . . . 5
			2.5. Registrars . . . . . . . . . . . . . . . . . . . . . . . 6
			2.6. DNS Hosting Operators . . . . . . . . . . . . . . . . . . 7
			2.7. Applications . . . . . . . . . . . . . . . . . . . . . . 7
			3. Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . 7
			4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8
			5. Security Considerations . . . . . . . . . . . . . . . . . . . 8
			Appendix A. Acknowledgements . . . . . . . . . . . . . . . . . . 8
			Appendix B. Changes . . . . . . . . . . . . . . . . . . . . . . 8
			Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 9
	1. Introduction		1. Introduction
	The DNS Security Extensions (DNSSEC), broadly defined in [RFC4033],		The DNS Security Extensions (DNSSEC), broadly defined in
	[RFC4034] and [RFC4035], make use of cryptographic algorithms in both		{{?RFC4033}}, {{?RFC4034}} and {{?RFC4035}}, make use of
	the signing of DNS records and the validation of DNSSEC signatures by		cryptographic algorithms in both the signing of DNS records and the
	recursive resolvers.		validation of DNSSEC signatures by recursive resolvers.
	The current list of cryptographic algorithms can be found in the IANA		The current list of cryptographic algorithms can be found in the IANA
	"Domain Name System Security (DNSSEC) Algorithm Numbers" registry		"Domain Name System Security (DNSSEC) Algorithm Numbers" registry
	located at http://www.iana.org/assignments/dns-sec-alg-numbers/		located at <http://www.iana.org/assignments/dns-sec-alg-numbers/>
	Algorithms are added to this IANA registry through a process defined		Algorithms are added to this IANA registry through a process defined
	in [RFC6014]. Note that [RFC6944] provides some guidance as to which		in {{?RFC6014}}. Note that {{?RFC6944}} provides some guidance as to
	of these algorithms should be implemented and supported.		which of these algorithms should be implemented and supported.
	Historically DNSSEC signatures have primarily used cryptographic		Historically DNSSEC signatures have primarily used cryptographic
	algorithms based on RSA keys. As deployment of DNSSEC has increased		algorithms based on RSA keys. As deployment of DNSSEC has increased
	there has been interest in using newer and more secure algorithms,		there has been interest in using newer and more secure algorithms,
	particularly those using elliptic curve cryptography.		particularly those using elliptic curve cryptography.
	The ECDSA algorithm [RFC6605] has seen some adoption and two new		The ECDSA algorithm {{?RFC6605}} has seen some adoption and two new
	algorithms are being proposed: Ed25519		algorithms are being proposed: Ed25519 and Ed448 .
	[I-D.ietf-curdle-dnskey-ed25519] and Ed448
	[I-D.ietf-curdle-dnskey-ed448].
	The challenge is that the deployment of a new cryptographic algorithm		The challenge is that the deployment of a new cryptographic algorithm
	for DNSSEC is not a simple process. DNSSEC algorithms are used		for DNSSEC is not a simple process. DNSSEC algorithms are used
	throughout the DNS infrastructure for tasks such as:		throughout the DNS infrastructure for tasks such as:
	o Generation of keys ("DNSKEY" record) for signing		o Generation of keys ("DNSKEY" record) for signing
	o Creation of DNSSEC signatures in zone files ("RRSIG")		o Creation of DNSSEC signatures in zone files ("RRSIG")
	o Usage in a Delegation Signer ("DS") record [RFC3658] for the		o Usage in a Delegation Signer ("DS") record {{?RFC3658}} for the
	"chain of trust" connecting back to the root of DNS		"chain of trust" connecting back to the root of DNS
	o Generation of NSEC/NSEC3 responses by authoritative DNS servers		o Generation of NSEC/NSEC3 responses by authoritative DNS servers
	o Validation of DNSSEC signatures by DNS resolvers		o Validation of DNSSEC signatures by DNS resolvers
	In order for a new cryptographic algorithm to be fully deployed, all		In order for a new cryptographic algorithm to be fully deployed, all
	aspects of the DNS infrastructure that interact with DNSSEC must be		aspects of the DNS infrastructure that interact with DNSSEC must be
	updated to use the new algorithm.		updated to use the new algorithm.
	This document outlines the current understanding of the components of		This document outlines the current understanding of the components of
	the DNS infrastructure that need to be updated to deploy a new		the DNS infrastructure that need to be updated to deploy a new
	cryptographic algorithm.		cryptographic algorithm.
	It should be noted that DNSSEC is not alone in complexity of		It should be noted that DNSSEC is not alone in complexity of
	deployment. The IAB documented "Guidelines for Cryptographic		deployment. The IAB documented "Guidelines for Cryptographic
	Algorithm Agility" in [RFC7696] to highlight the importance of this		Algorithm Agility" in {{?RFC7696}} to highlight the importance of
	issue.		this issue.
	1.1. Terminology		1.1. Terminology
	In this document, the key words "MUST", "MUST NOT", "REQUIRED",		In this document, the key words "MUST", "MUST NOT", "REQUIRED",
	"SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY",		"SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY",
	and "OPTIONAL" are to be interpreted as described in BCP 14, RFC 2119		and "OPTIONAL" are to be interpreted as described in BCP 14, RFC 2119
	[RFC2119].		.
	2. Aspects of Deploying New Algorithms		2. Aspects of Deploying New Algorithms
	For a new cryptographic algorithm to be deployed in DNSSEC, the		For a new cryptographic algorithm to be deployed in DNSSEC, the
	following aspects of the DNS infrastructure must be updated:		following aspects of the DNS infrastructure must be updated:
	o DNS resolvers performing validation		o DNS resolvers performing validation
	o Authoritative DNS servers		o Authoritative DNS servers
	skipping to change at page 4, line 12 ¶		skipping to change at page 4, line 30 ¶
	updated. In some cases this could require waiting until an		updated. In some cases this could require waiting until an
	underlying library is updated to support the new algorithm.		underlying library is updated to support the new algorithm.
	Once the software is updated, the updates need to be deployed to all		Once the software is updated, the updates need to be deployed to all
	resolvers using that software. This can be challenging in cases of		resolvers using that software. This can be challenging in cases of
	customer-premises equipment (CPE) that does not have any mechanism		customer-premises equipment (CPE) that does not have any mechanism
	for automatic updating.		for automatic updating.
	2.1.1. Resolvers and Unknown Algorithms		2.1.1. Resolvers and Unknown Algorithms
	It should be noted that section 5.2 of [RFC4035] states:		It should be noted that section 5.2 of {{?RFC4035}} states:
	"If the resolver does not support any of the algorithms listed in an		"If the resolver does not support any of the algorithms listed in an
	authenticated DS RRset, then the resolver will not be able to verify		authenticated DS RRset, then the resolver will not be able to verify
	the authentication path to the child zone. In this case, the		the authentication path to the child zone. In this case, the
	resolver SHOULD treat the child zone as if it were unsigned."		resolver SHOULD treat the child zone as if it were unsigned."
	This means that signing a zone with a new algorithm that is not		This means that signing a zone with a new algorithm that is not
	widely supported by DNS resolvers would result in the signatures		widely supported by DNS resolvers would result in the signatures
	being ignored and the zone treated as unsigned until resolvers were		being ignored and the zone treated as unsigned until resolvers were
	updated to recognize the new algorithm.		updated to recognize the new algorithm.
			Note that in at least one 2016 case (an ISP in Sweden) the resolver
			software deployed on customer premises turned out not to be compliant
			with RFC 4035. Instead of ignoring the signatures using unknown
			algorithms and treating the zones as unsigned, the validating
			resolver rejected the signatures and returned a SERVFAIL to the DNS
			query. This resulted in the ISP turning off DNSSEC validation on the
			equipment. Further investigation showed that a newer version of the
			resolver software did correctly support ECDSA, but now all customer
			premises equipment must be updated to this new version.
			The point is that it is not safe to assume all resolver software will
			correctly implement this part of RFC 4035.
	2.2. Authoritative DNS Servers		2.2. Authoritative DNS Servers
	Authoritative DNS servers serve out signed DNS records. Serving new		Authoritative DNS servers serve out signed DNS records. Serving new
	DNSSEC signing algorithms should not be a problem as a well-written		DNSSEC signing algorithms should not be a problem as a well-written
	authoritative DNS server implementation should be agnostic to the RR		authoritative DNS server implementation should be agnostic to the RR
	DATA they serve.		DATA they serve.
	The one exception is if the new cryptographic algorithms are used in		The one exception is if the new cryptographic algorithms are used in
	the creation of NSEC/NSEC3 responses. In the case of new NSEC/NSEC3		the creation of NSEC/NSEC3 responses. In the case of new NSEC/NSEC3
	algorithms, the authoritative DNS server software would need to be		algorithms, the authoritative DNS server software would need to be
	skipping to change at page 6, line 12 ¶		skipping to change at page 6, line 44 ¶
	cryptographic algorithms need to be added to the web interface in		cryptographic algorithms need to be added to the web interface in
	order to be accepted into the registrar's system.		order to be accepted into the registrar's system.
	Additionally, in a manner similar to registries, many registrars		Additionally, in a manner similar to registries, many registrars
	perform some level of verification on the DS record to ensure it was		perform some level of verification on the DS record to ensure it was
	entered "correctly". To do this verification, the registrar's		entered "correctly". To do this verification, the registrar's
	software needs to understand the algorithm used in the DS record.		software needs to understand the algorithm used in the DS record.
	This requires the software to be updated to support the new		This requires the software to be updated to support the new
	algorithm.		algorithm.
	Note that work is currently underway in [I-D.ietf-dnsop-maintain-ds]		Note that work is currently underway in {{?I-D.ietf-dnsop-maintain-
	to provide an automated mechanism to update the DS records with a		ds}} to provide an automated mechanism to update the DS records with
	registry. If this method becomes widely adopted, registrar web		a registry. If this method becomes widely adopted, registrar web
	interfaces may no longer be needed.		interfaces may no longer be needed.
	2.6. DNS Hosting Operators		2.6. DNS Hosting Operators
	DNS hosting operators are entities that are operating the		DNS hosting operators are entities that are operating the
	authoritative DNS servers for domains and with DNSSEC are also		authoritative DNS servers for domains and with DNSSEC are also
	providing the signing of zones. In many cases they may also be the		providing the signing of zones. In many cases they may also be the
	registrar for domain names, but in other cases they are a separate		registrar for domain names, but in other cases they are a separate
	entity providing DNS services to customers.		entity providing DNS services to customers.
	skipping to change at page 7, line 31 ¶		skipping to change at page 8, line 19 ¶
	4. IANA Considerations		4. IANA Considerations
	This document does not make any requests of IANA.		This document does not make any requests of IANA.
	5. Security Considerations		5. Security Considerations
	No new security considerations are created by this document.		No new security considerations are created by this document.
	It should be noted that there are security considerations regarding		It should be noted that there are security considerations regarding
	changing DNSSEC algorithms that are mentioned in both [RFC6781] and		changing DNSSEC algorithms that are mentioned in both {{?RFC6781}}
	[RFC7583].		and {{?RFC7583}}.
	6. Acknowledgements		Appendix A. Acknowledgements
	The information in this document evolved out of several mailing list		The information in this document evolved out of several mailing list
	discussions and also through engagement with participants in the		discussions and also through engagement with participants in the
	following sessions or events:		following sessions or events:
	o DNSSEC Workshop at ICANN 53 (Buenos Aires)		o DNSSEC Workshop at ICANN 53 (Buenos Aires)
	o DNSSEC Workshop at ICANN 55 (Marrakech)		o DNSSEC Workshop at ICANN 55 (Marrakech)
	o Spring 2016 DNS-OARC meeeting (Buenos Aires)		o Spring 2016 DNS-OARC meeeting (Buenos Aires)
	skipping to change at page 8, line 4 ¶		skipping to change at page 8, line 39 ¶
	o DNSSEC Workshop at ICANN 55 (Marrakech)		o DNSSEC Workshop at ICANN 55 (Marrakech)
	o Spring 2016 DNS-OARC meeeting (Buenos Aires)		o Spring 2016 DNS-OARC meeeting (Buenos Aires)
	o various IETF 95 working groups (Buenos Aires)		o various IETF 95 working groups (Buenos Aires)
	o Panel session at RIPE 72 (Copenhagen)		o Panel session at RIPE 72 (Copenhagen)
	o DNSSEC Workshop at ICANN 56 (Helsinki)		o DNSSEC Workshop at ICANN 56 (Helsinki)
	The authors thank the participants of the various sessions for their		The authors thank the participants of the various sessions for their
	feedback.		feedback.
	7. Changes		Appendix B. Changes
	NOTE TO RFC EDITOR - Please remove this "Changes" section prior to		NOTE TO RFC EDITOR - Please remove this "Changes" section prior to
	publication. Thank you.		publication. Thank you.
			o Revision -02 added text to the resolver section about an example
			where resolver software did not correctly follow RFC 4035 and
			treat packets with unknown algorithms as unsigned. The markdown
			source of this I-D was also migrated to the markdown syntax
			favored by the 'mmark' tool.
	o Revision -01 adds text about authoritative servers needing an		o Revision -01 adds text about authoritative servers needing an
	update if the algorithm is for NSEC/NSEC3. Also expands		update if the algorithm is for NSEC/NSEC3. Also expands
	acknowledgements.		acknowledgements.
	8. References
	8.1. Normative References
	[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
	Requirement Levels", BCP 14, RFC 2119, March 1997.
	8.2. Informative References
	[RFC4033] Arends, R., Austein, R., Larson, M., Massey, D., and S.
	Rose, "DNS Security Introduction and Requirements", RFC
	4033, DOI 10.17487/RFC4033, March 2005,
	<http://www.rfc-editor.org/info/rfc4033>.
	[RFC4034] Arends, R., Austein, R., Larson, M., Massey, D., and S.
	Rose, "Resource Records for the DNS Security Extensions",
	RFC 4034, DOI 10.17487/RFC4034, March 2005,
	<http://www.rfc-editor.org/info/rfc4034>.
	[RFC4035] Arends, R., Austein, R., Larson, M., Massey, D., and S.
	Rose, "Protocol Modifications for the DNS Security
	Extensions", RFC 4035, DOI 10.17487/RFC4035, March 2005,
	<http://www.rfc-editor.org/info/rfc4035>.
	[RFC6014] Hoffman, P., "Cryptographic Algorithm Identifier
	Allocation for DNSSEC", RFC 6014, DOI 10.17487/RFC6014,
	November 2010, <http://www.rfc-editor.org/info/rfc6014>.
	[RFC6944] Rose, S., "Applicability Statement: DNS Security (DNSSEC)
	DNSKEY Algorithm Implementation Status", RFC 6944, DOI
	10.17487/RFC6944, April 2013,
	<http://www.rfc-editor.org/info/rfc6944>.
	[RFC6605] Hoffman, P. and W. Wijngaards, "Elliptic Curve Digital
	Signature Algorithm (DSA) for DNSSEC", RFC 6605, DOI
	10.17487/RFC6605, April 2012,
	<http://www.rfc-editor.org/info/rfc6605>.
	[I-D.ietf-curdle-dnskey-ed25519]
	Sury, O. and R. Edmonds, "Ed25519 for DNSSEC", draft-ietf-
	curdle-dnskey-ed25519-01 (work in progress), February
	2016.
	[I-D.ietf-curdle-dnskey-ed448]
	Sury, O. and R. Edmonds, "Ed448 for DNSSEC", draft-ietf-
	curdle-dnskey-ed448-00 (work in progress), March 2016.
	[RFC3658] Gudmundsson, O., "Delegation Signer (DS) Resource Record
	(RR)", RFC 3658, DOI 10.17487/RFC3658, December 2003,
	<http://www.rfc-editor.org/info/rfc3658>.
	[RFC7696] Housley, R., "Guidelines for Cryptographic Algorithm
	Agility and Selecting Mandatory-to-Implement Algorithms",
	BCP 201, RFC 7696, DOI 10.17487/RFC7696, November 2015,
	<http://www.rfc-editor.org/info/rfc7696>.
	[I-D.ietf-dnsop-maintain-ds]
	Gu[eth]mundsson, O. and P. Wouters, "Managing DS records
	from parent via CDS/CDNSKEY", draft-ietf-dnsop-maintain-
	ds-01 (work in progress), March 2016.
	[RFC6781] Kolkman, O., Mekking, W., and R. Gieben, "DNSSEC
	Operational Practices, Version 2", RFC 6781, DOI 10.17487/
	RFC6781, December 2012,
	<http://www.rfc-editor.org/info/rfc6781>.
	[RFC7583] Morris, S., Ihren, J., Dickinson, J., and W. Mekking,
	"DNSSEC Key Rollover Timing Considerations", RFC 7583, DOI
	10.17487/RFC7583, October 2015,
	<http://www.rfc-editor.org/info/rfc7583>.
	Authors' Addresses		Authors' Addresses
	Dan York		Dan York
	Internet Society		Internet Society
	Email: york@isoc.org		Email: york@isoc.org
	Ondrej Sury		Ondrej Sury
	CZ.NIC		CZ.NIC
	Email: ondrej.sury@nic.cz		Email: ondrej.sury@nic.cz
	Paul Wouters		Paul Wouters
	Red Hat		Red Hat
	Email: pwouters@redhat.com		Email: pwouters@redhat.com
End of changes. 23 change blocks.
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