< draft-ietf-dnsop-delegation-trust-maintainance-02.txt		draft-ietf-dnsop-delegation-trust-maintainance-03.txt >
	dnsop W. Kumari		dnsop W. Kumari
	Internet-Draft Google		Internet-Draft Google
	Intended status: Informational O. Gudmundsson		Intended status: Informational O. Gudmundsson
	Expires: August 9, 2014 Shinkuro Inc.		Expires: August 12, 2014 Shinkuro Inc.
	G. Barwood		G. Barwood
	February 5, 2014		February 8, 2014
	Automating DNSSEC delegation trust maintenance		Automating DNSSEC delegation trust maintenance
	draft-ietf-dnsop-delegation-trust-maintainance-02		draft-ietf-dnsop-delegation-trust-maintainance-03
	Abstract		Abstract
	This document describes a method to allow DNS operators to more		This document describes a method to allow DNS operators to more
	easily update DNSSEC Key Signing Keys using DNS as communication		easily update DNSSEC Key Signing Keys using DNS as communication
	channel. This document does not address the initial configuration of		channel. This document does not address the initial configuration of
	trust anchors for a domain. The technique described is aimed at		trust anchors for a domain. The technique described is aimed at
	delegations in which it is currently hard to move information from		delegations in which it is currently hard to move information from
	the child to parent.		the child to parent.
	skipping to change at page 1, line 38 ¶		skipping to change at page 1, line 38 ¶
	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 August 9, 2014.		This Internet-Draft will expire on August 12, 2014.
	Copyright Notice		Copyright Notice
	Copyright (c) 2014 IETF Trust and the persons identified as the		Copyright (c) 2014 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
	skipping to change at page 3, line 29 ¶		skipping to change at page 3, line 29 ¶
	[RFC4034], [RFC4035], [RFC5011] and [RFC6781].		[RFC4034], [RFC4035], [RFC5011] and [RFC6781].
	This document is a compilation of two earlier drafts: draft-barwood-		This document is a compilation of two earlier drafts: draft-barwood-
	dnsop-ds-publish[I-D.ds-publish] and draft-wkumari-dnsop-ezkeyroll.		dnsop-ds-publish[I-D.ds-publish] and draft-wkumari-dnsop-ezkeyroll.
	This document outlines a technique in which the parent periodically		This document outlines a technique in which the parent periodically
	(or upon request) polls its signed children and automatically publish		(or upon request) polls its signed children and automatically publish
	new DS records. To a large extent, the procedures this document		new DS records. To a large extent, the procedures this document
	follows are as described in [RFC6781] section 4.1.2.		follows are as described in [RFC6781] section 4.1.2.
	This technique is in some ways similar to RFC 5011 style rollovers,		This technique is in some ways similar to [RFC5011] style rollovers,
	but for sub-domains DS records, instead of trust anchors.		but for sub-domains DS records, instead of trust anchors.
	This technique is designed to be friendly both to fully automated		This technique is designed to be friendly both to fully automated
	tools and humans. Fully automated tools can perform all the actions		tools and humans. Fully automated tools can perform all the actions
	needed without human intervention, and thus can monitor when it is		needed without human intervention, and thus can monitor when it is
	safe to move to the next step.		safe to move to the next step.
	The solution described in this document only allows transferring		The solution described in this document only allows transferring
	information about DNSSEC keys (DS and DNSKEY) from the child to the		information about DNSSEC keys (DS and DNSKEY) from the child to the
	parental agent. It lists exactly what the parent should publish, and		parental agent. It lists exactly what the parent should publish, and
	skipping to change at page 7, line 33 ¶		skipping to change at page 7, line 33 ¶
	-- or worse, the update action is not performed at all.		-- or worse, the update action is not performed at all.
	3. CDS / CDNSKEY (Child DS/ Child DNSKEY) record definitions		3. CDS / CDNSKEY (Child DS/ Child DNSKEY) record definitions
	This document specifies two new DNS RRtypes (CDS and CDNSKEY) that		This document specifies two new DNS RRtypes (CDS and CDNSKEY) that
	indicates what the Child wants the parent's DS RRset to contain. It		indicates what the Child wants the parent's DS RRset to contain. It
	allows the Child to present DS records and / or DNSKEY records (for		allows the Child to present DS records and / or DNSKEY records (for
	those parents who would rather generate the DS records for their		those parents who would rather generate the DS records for their
	children).		children).
	The CDS / CDNSKEY record is published in the child zone and gives the		The CDS / CDNSKEY records are published in the child zone and gives
	child control of what is published for it in the parental zone. The		the child control of what is published for it in the parental zone.
	CDS / CDNSKEY RRset expresses what the child would like the DS RRset		The CDS / CDNSKEY RRset expresses what the child would like the DS
	to look like after the change; it is a "replace" operation, and it is		RRset to look like after the change; it is a "replace" operation, and
	up to the consumer of the records to translate that into the		it is up to the consumer of the records to translate that into the
	appropriate add/delete operations in the registration systems (and in		appropriate add/delete operations in the registration systems (and in
	the case of CDNSKEY, to generate the DS from the DNSKEY).		the case of CDNSKEY, to generate the DS from the DNSKEY). If no CDS
			/ CDNSKEY RRset is present in child, this means that no change is
			needed.
	[[RFC Editor: Please remove this paragraph before publication]		[[RFC Editor: Please remove this paragraph before publication]
	Version -04 of the ID that became this document (http://		Version -04 of the ID that became this working group document (http:/
	tools.ietf.org/id/draft-kumari-ogud-dnsop-cds-04.txt) defined a new		/tools.ietf.org/id/draft-kumari-ogud-dnsop-cds-04.txt) defined a new
	record (CTA) that could hold either a DS or a DNSKEY record (with a		record (CTA) that could hold either a DS or a DNSKEY record (with a
	selector to differentiate between them). In a shocking development,		selector to differentiate between them). In a shocking development,
	there was almost full consensus that this was horrid :-) ]		there was almost full consensus that this was horrid :-) ]
	3.1. CDS Resource Record Format		3.1. CDS Resource Record Format
	The wire and presentation format of the CDS ("Child DS") record is		The wire and presentation format of the CDS ("Child DS") record is
	identical to the DS record [RFC4034]. IANA has allocated RR code 59		identical to the DS record [RFC4034]. IANA has allocated RR code 59
	for the CDS record via expert review [I-D.ds-publish].		for the CDS record via expert review [I-D.ds-publish]. CDS uses the
			same registries as DS for its fields
	No special processing is performed by authoritative servers or by		No special processing is performed by authoritative servers or by
	revolvers, when serving or resolving. For all practical purposes CDS		revolvers, when serving or resolving. For all practical purposes CDS
	is a regular RR type.		is a regular RR type.
	3.2. CDNSKEY Resource Record Format		3.2. CDNSKEY Resource Record Format
	The wire and presentation format of the CDNSKEY ("Child DNSKEY")		The wire and presentation format of the CDNSKEY ("Child DNSKEY")
	record is identical to the DNSKEY record.		record is identical to the DNSKEY record. CDNSKEY uses the same
			registries as DNSKEY for its fields.
	No special processing is performed by authoritative servers or by		No special processing is performed by authoritative servers or by
	revolvers, when serving or resolving. For all practical purposes		revolvers, when serving or resolving. For all practical purposes
	CDNSKEY is a regular RR type.		CDNSKEY is a regular RR type.
	4. Automating DS maintainance with CDS/CDNSKEY records		4. Automating DS maintainance with CDS/CDNSKEY records
	CDS/CDNSKEY records are intended to be "consumed" by delegation trust		CDS/CDNSKEY records are intended to be "consumed" by delegation trust
	maintainers. The use of CDS/CDNSKEY is optional.		maintainers. The use of CDS/CDNSKEY is optional.
	Some parents prefer to accept DNSSEC key information in DS format,		Some parents prefer to accept DNSSEC key information in DS format,
	some parents prefer to accept it in DNSKEY format, and calculate the		some parents prefer to accept it in DNSKEY format, and calculate the
	DS record on the child's behalf. Each method has pros and cons, both		DS record on the child's behalf. Each method has pros and cons, both
	technical and policy. This solution is DS vs DNSKEY agnostic, and		technical and policy. This solution is DS vs DNSKEY agnostic, and
	allows operation with either.		allows operation with either.
	If the child knows what the parent prefers, they can publish the		If the child knows what the parent prefers, they can publish the
	parent's preferred record type. If the child does not know (or		parent's preferred record type. If the child does not know (or
	simply chooses to), they can publish both CDS and CDNSKEY. If the		simply chooses to), they can publish both CDS and CDNSKEY. If the
	child publishes both, they SHOULD have matching CDS records for each		child publishes both, the two RRsets they SHOULD match in content.
	CDNSKEY record. The parent should use whichever one they choose, but		The parent should use whichever one they choose, but SHOULD NOT query
	SHOULD NOT query for both and perform consistency checks between the		for both and perform consistency checks between the CDS and CDNSKEY
	CDS and CDNSKEY records.		records.
	[Editor note: It is not an error for a child to have published CDS		[Editor note: It is not an error for a child to have published CDS
	records and not have CDNSKEYs that hash to those records, nor for		records and not have CDNSKEYs that hash to those records, nor for
	there to be CDNSKEY records without matching DS records. This is		there to be CDNSKEY records without matching DS records. This is
	because a child might have been publishing CDS records and then the		because a child might have been publishing CDS records and then the
	parent's policy changes to require CDNSKEY records. The child might		parent's policy changes to require CDNSKEY records. The child might
	forget to remove the CDS, etc. This avoids all sorts of error		forget to remove the CDS, etc. This avoids all sorts of error
	conditions / complexity, etc.]		conditions / complexity, etc.]
	4.1. CDS / CDNSKEY processing rules		4.1. CDS / CDNSKEY processing rules
	Absence of CDS / CDNSKEY in child signals "No change" to the current		If there are no CDS / CDNSKEY resource records in the child, this
	DS set. Following acceptance rules are placed on the CDS / CDNSKEY		signals that no change should be made to the current DS set. This
	records as follows:		means that, once the child and parent are in sync, the child DNS
			operator MAY remove all CDS records from the zone.
			Following acceptance rules are placed on the CDS / CDNSKEY records as
			follows:
	o Location: "the CDS / CDNSKEY record MUST be at the child zone		o Location: "the CDS / CDNSKEY record MUST be at the child zone
	apex".		apex".
	o Signer: "MUST be signed with a key that is represented in both the		o Signer: "MUST be signed with a key that is represented in both the
	current DNSKEY and DS RRset's."		current DNSKEY and DS RRset's."
	o Continuity: "SHOULD NOT break the current delegation if applied to		o Continuity: "SHOULD NOT break the current delegation if applied to
	DS RRset"		DS RRset"
	If any these conditions fail the CDS / CDNSKEY record MUST be		If any these conditions fail the CDS / CDNSKEY record MUST be
	ignored.		ignored.
	5. Child's CDS / CDNSKEY Publication		5. Child's CDS / CDNSKEY Publication
	Child DNS Operator SHOULD only publish a CDS or CDNSKEY RRset when it		Child DNS Operator SHOULD only publish a CDS or CDNSKEY RRset when it
	wants to make a change to the DS RRset in the Parent. The CDS /		wants to make a change to the DS RRset in the Parent. The CDS /
	CDNSKEY RRset SHOULD be compliant with the rules in Section 4.1.		CDNSKEY RRset SHOULD be compliant with the rules in Section 4.1.
	When the Parent DS is "in-sync" with the CDS, the Child DNS Operator		When the Parent DS is "in-sync" with the CDS / CDNSKEY, the Child DNS
	MAY delete the CDS RRset. Note that if the child has published a		Operator MAY delete the CDS / CDNSKEY RRset(s). Note that if the
	DNSKEY RR in the CDS, it will have to calculate the DS (using the		child has published a DNSKEY RR in the CDS, it will have to calculate
	requested digest algorithm) to do the comparison.		the DS (using the requested digest algorithm) to do the comparison.
	A child MAY publish both CDS and CDNSKEY. If a child chooses to		A child MAY publish both CDS and CDNSKEY. If a child chooses to
	publish both, it SHOULD attempt to maintain consistency (a matching		publish both, it SHOULD attempt to maintain consistency (a matching
	CDS for each CDNSKEY)		CDS for each CDNSKEY)
	6. Parent side CDS / CDNSKEY Consumption		6. Parent side CDS / CDNSKEY Consumption
	The CDS / CDNSKEY RRset MAY be used by the Parental Agent to update		The CDS / CDNSKEY RRset MAY be used by the Parental Agent to update
	the DS RRset in the parent zone. The Parental Agent for this uses a		the DS RRset in the parent zone. The Parental Agent for this uses a
	tool that understands the CDS / CDNSKEY signing rules from		tool that understands the CDS / CDNSKEY signing rules from
	skipping to change at page 11, line 12 ¶		skipping to change at page 11, line 12 ¶
	unauthenticated POST could be made to a webserver (with rate-		unauthenticated POST could be made to a webserver (with rate-
	limiting), etc.)		limiting), etc.)
	Other documents can specify the trigger conditions.		Other documents can specify the trigger conditions.
	6.2. Using the new CDS / CDNSKEY records		6.2. Using the new CDS / CDNSKEY records
	Regardless of how the Parental Agent detected changes to a CDS /		Regardless of how the Parental Agent detected changes to a CDS /
	CDNSKEY RR, the Parental Agent MUST use a DNSSEC validator to obtain		CDNSKEY RR, the Parental Agent MUST use a DNSSEC validator to obtain
	a validated CDS / CDNSKEY RRset from the Child zone. It would be a		a validated CDS / CDNSKEY RRset from the Child zone. It would be a
	good idea if the Parental Agent checked all NS RRs listed at the		good idea if the Parental Agent checked all NS RRs listed at the
	delegation. However, due to the use of technologies such as load		delegation.
	balancing and anycast, this should not be taken as proof that the new
	CDS / CDNSKEY is present on all nodes serving the Child zone.
	The Parental Agent MUST ensure that old versions of the CDS / CDNSKEY		The Parental Agent MUST ensure that old versions of the CDS / CDNSKEY
	RRset do not overwrite newer versions. This MAY be accomplished by		RRset do not overwrite newer versions. This MAY be accomplished by
	checking that the signature inception in the RRSIG for CDS / CDNSKEY		checking that the signature inception in the RRSIG for CDS / CDNSKEY
	is newer and/or the serial number on the child's SOA is greater.		is newer and/or the serial number on the child's SOA is greater.
	This may require the Parental Agent to maintain some state		This may require the Parental Agent to maintain some state
	information.		information.
	The Parental Agent MAY take extra security measures. For example, to		The Parental Agent MAY take extra security measures. For example, to
	mitigate the possibility that a Child's key signing key has been		mitigate the possibility that a Child's key signing key has been
	skipping to change at page 12, line 44 ¶		skipping to change at page 12, line 42 ¶
	If child breaks DNSSEC validation by removing all the DNSKEYs that		If child breaks DNSSEC validation by removing all the DNSKEYs that
	are represented in the DS set its only repair actions are to contact		are represented in the DS set its only repair actions are to contact
	the parent or restore the DNSKEYs in the DS set.		the parent or restore the DNSKEYs in the DS set.
	In the event of a compromise of the server or system generating		In the event of a compromise of the server or system generating
	signatures for a zone, an attacker might be able to generate and		signatures for a zone, an attacker might be able to generate and
	publish new CDS records. The modified CDS records will be picked up		publish new CDS records. The modified CDS records will be picked up
	by this technique and so may allow the attacker to extend the		by this technique and so may allow the attacker to extend the
	effective time of his attack. If there a delay in accepting changes		effective time of his attack. If there a delay in accepting changes
	to DS, as in RFC5011, then the attacker needs to hope his activity is		to DS, as in [RFC5011], then the attacker needs to hope his activity
	not detected before the DS in parent is changed. If this type of		is not detected before the DS in parent is changed. If this type of
	change takes place, the child needs to contact the parent (possibly		change takes place, the child needs to contact the parent (possibly
	via a registrar web interface) and remove any compromised DS keys.		via a registrar web interface) and remove any compromised DS keys.
	A compromise of the account with the parent (e.g. registrar) will not		A compromise of the account with the parent (e.g. registrar) will not
	be mitigated by this technique, as the "new registrant" can delete/		be mitigated by this technique, as the "new registrant" can delete/
	modify the DS records at will.		modify the DS records at will.
	While it may be tempting, this SHOULD NOT be used for initial		While it may be tempting, this SHOULD NOT be used for initial
	enrollment of keys since there is no way to ensure that the initial		enrollment of keys since there is no way to ensure that the initial
	key is the correct one. If is used, strict rules for inclusion of		key is the correct one. If is used, strict rules for inclusion of
	keys like hold down times, challenge data inclusion etc., ought to be		keys like hold down times, challenge data inclusion etc., ought to be
	used, along with some kind of challenge mechanism.		used, along with some kind of challenge mechanism. A child cannot
			use this mechanism to go from signed to unsigned (publishing an empty
			CDS / CDNSKEY RRset means no-change should be made in the parent).
	The CDS RR type should allow for enhanced security by simplifying		The CDS RR type should allow for enhanced security by simplifying
	process. Since rollover is automated, updating a DS RRset by other		process. Since rollover is automated, updating a DS RRset by other
	means may be regarded as unusual and subject to extra security		means may be regarded as unusual and subject to extra security
	checks.		checks.
	If there is a failure in applying changes in child zone to all DNS		If there is a failure in applying changes in child zone to all DNS
	servers listed in either parent or child NS set it is possible that		servers listed in either parent or child NS set it is possible that
	the Parental agent may get confused either not perform action because		the Parental agent may get confused either not perform action because
	it gets different answers on different checks or CDS validation		it gets different answers on different checks or CDS validation
	skipping to change at page 13, line 48 ¶		skipping to change at page 13, line 47 ¶
	By automating the maintenance of the DNSSEC key information (and		By automating the maintenance of the DNSSEC key information (and
	removing humans from the process) we expect to decrease the number of		removing humans from the process) we expect to decrease the number of
	DNSSEC related outages, which should increase DNSSEC deployment.		DNSSEC related outages, which should increase DNSSEC deployment.
	10. Acknowledgements		10. Acknowledgements
	We would like to thank a large number of folk, including: Mark		We would like to thank a large number of folk, including: Mark
	Andrews, Joe Abley, Jaap Akkerhuis, Roy Arends, Doug Barton, Brian		Andrews, Joe Abley, Jaap Akkerhuis, Roy Arends, Doug Barton, Brian
	Dickinson, Paul Ebersman, Tony Finch, Patrik Faltsrom, Jim Galvin,		Dickinson, Paul Ebersman, Tony Finch, Patrik Faltsrom, Jim Galvin,
	Paul Hoffman, Olaf Kolkman, Cricket Liu, Stephan Lagerholm, Matt		Paul Hoffman, Samir Hussain, Tatuya Jinmei, Olaf Kolkman, Cricket
	Larson, Marco Sanz, Antoin Verschuren, Suzanne Woolf, Paul Wouters,		Liu, Stephan Lagerholm, Matt Larson, Marco Sanz, Antoin Verschuren,
	Matthijs Meeking, John Dickinson, Timothe Litt and Edward Lewis.		Suzanne Woolf, Paul Wouters, Matthijs Meeking, John Dickinson,
			Timothe Litt and Edward Lewis.
	Special thanks to Wes Hardaker for contributing significant text and		Special thanks to Wes Hardaker for contributing significant text and
	creating the complementary (CSYNC) solution, and to Paul Hoffman and		creating the complementary (CSYNC) solution, and to Paul Hoffman and
	Mukund Sivaraman for text and review.		Mukund Sivaraman for text and review.
	There were a number of other folk with whom we discussed this,		There were a number of other folk with whom we discussed this,
	apologies for not remembering everyone.		apologies for not remembering everyone.
	11. References		11. References
	skipping to change at page 16, line 9 ¶		skipping to change at page 16, line 9 ¶
	In many RRR cases the Registrar and Registry communicate via		In many RRR cases the Registrar and Registry communicate via
	EPP[RFC5730] and use the EPP DNSSEC extension [RFC5910]. In a number		EPP[RFC5730] and use the EPP DNSSEC extension [RFC5910]. In a number
	of ccTLDs there are other mechanisms in use as well as EPP, but in		of ccTLDs there are other mechanisms in use as well as EPP, but in
	general there seems to be a movement towards EPP usage when DNSSEC is		general there seems to be a movement towards EPP usage when DNSSEC is
	enabled in the TLD.		enabled in the TLD.
	Appendix B. Changes / Author Notes.		Appendix B. Changes / Author Notes.
	[RFC Editor: Please remove this section before publication ]		[RFC Editor: Please remove this section before publication ]
			WG-02 to WG-03
			o Fixed some references to RFC 5011 - from Samir Hussain.
			o Fixed some spelling / typos - from Samir Hussain.
			o A number of clarifiations on the meaning on an empty / non-
			existant CDS RRset - thanks to JINMEI, Tatuya
			o Be consistent in mentioning both CDS and CDNSKEY throughout the
			document.
	WG-01 to WG-02		WG-01 to WG-02
	o Many nits and suggestions from Mukund.		o Many nits and suggestions from Mukund.
	o Matthijs: " I still think that it is too strong that the Child DNS		o Matthijs: " I still think that it is too strong that the Child DNS
	Operator SHOULD/MUST delete the CDS RRset when the Parent DS is		Operator SHOULD/MUST delete the CDS RRset when the Parent DS is
	"in-sync". This should be a MAY"		"in-sync". This should be a MAY"
	WG-00 to WG-01		WG-00 to WG-01
	skipping to change at page 16, line 31 ¶		skipping to change at page 16, line 43 ¶
	strategies." Thanks to Paul for providing text.		strategies." Thanks to Paul for providing text.
	From -05 to WG-00:		From -05 to WG-00:
	o Nothing rchanged, resubmit under new name.		o Nothing rchanged, resubmit under new name.
	From 04 to 05		From 04 to 05
	o Renamed the record back to CDS.		o Renamed the record back to CDS.
	o
	From 03 to 04.		From 03 to 04.
	o Added text explaining that CDS and CSYNC complement each other,		o Added text explaining that CDS and CSYNC complement each other,
	not replace or compete.		not replace or compete.
	o Changed format of record to be <selector> <data> to allow the		o Changed format of record to be <selector> <data> to allow the
	publication of DS **or** DNSKEY.		publication of DS **or** DNSKEY.
	o Bunch of text changed to cover the above.		o Bunch of text changed to cover the above.
	o Added a bit more text on the polling scaling stuff, expecation		o Added a bit more text on the polling scaling stuff, expectation
	that other triggers will be documented,		that other triggers will be documented.
	From 02 to 03		From 02 to 03
	o Applied comments by Matthijs Mekking		o Applied comments by Matthijs Mekking
	o Incorporated suggestions from Edward Lewis about structure		o Incorporated suggestions from Edward Lewis about structure
	o Reworked structure to be easier for implementors to follow		o Reworked structure to be easier for implementors to follow
	o Applied many suggestions from a wonderful thorough review by John		o Applied many suggestions from a wonderful thorough review by John
	Dickinson		Dickinson
	o Removed the going Unsigned option		o Removed the going Unsigned option
	From 01 to 02		From 01 to 02
	o Major restructuring to facilitate easier discussion		o Major restructuring to facilitate easier discussion
	o Lots of comments from DNSOP mailing list incorporated, including		o Lots of comments from DNSOP mailing list incorporated, including
End of changes. 21 change blocks.
	39 lines changed or deleted		59 lines changed or added
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