< draft-ietf-dane-srv-03.txt		draft-ietf-dane-srv-04.txt >
	DNS-Based Authentication of Named Entities (DANE) T. Finch		DNS-Based Authentication of Named Entities (DANE) T. Finch
	Internet-Draft University of Cambridge		Internet-Draft University of Cambridge
	Intended status: Standards Track M. Miller		Intended status: Standards Track M. Miller
	Expires: June 16, 2014 P. Saint-Andre		Expires: August 15, 2014 Cisco Systems, Inc.
	Cisco Systems, Inc.		P. Saint-Andre
	December 13, 2013		&yet
			February 11, 2014
	Using DNS-Based Authentication of Named Entities (DANE) TLSA records		Using DNS-Based Authentication of Named Entities (DANE) TLSA records
	with SRV and MX records.		with SRV and MX records.
	draft-ietf-dane-srv-03		draft-ietf-dane-srv-04
	Abstract		Abstract
	The DANE specification (RFC 6698) describes how to use TLSA resource		The DANE specification (RFC 6698) describes how to use TLSA resource
	records in the DNS to associate a server's host name with its TLS		records in the DNS to associate a server's host name with its TLS
	certificate. The association is secured with DNSSEC. Some		certificate. The association is secured with DNSSEC. Some
	application protocols use SRV records (RFC 2782) to indirectly name		application protocols use SRV records (RFC 2782) to indirectly name
	the server hosts for a service domain (SMTP uses MX records for the		the server hosts for a service domain (SMTP uses MX records for the
	same purpose). This specification gives generic instructions for how		same purpose). This specification gives generic instructions for how
	these application protocols locate and use TLSA records when		these application protocols locate and use TLSA records when
	skipping to change at page 1, line 41 ¶		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 June 16, 2014.		This Internet-Draft will expire on August 15, 2014.
	Copyright Notice		Copyright Notice
	Copyright (c) 2013 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
	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 . . . . . . . . . . . . . . . . . . . . . . . . 2		1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
	2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3		2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
	3. Relation between SRV and MX records . . . . . . . . . . . . . 3		3. Relation between SRV and MX records . . . . . . . . . . . . . 3
	4. DNS Checks for TLSA and SRV Records . . . . . . . . . . . . . 4		4. DNS Checks for TLSA and SRV Records . . . . . . . . . . . . . 4
	4.1. SRV Query . . . . . . . . . . . . . . . . . . . . . . . . 4		4.1. SRV Query . . . . . . . . . . . . . . . . . . . . . . . . 4
	4.2. TLSA Queries . . . . . . . . . . . . . . . . . . . . . . 5		4.2. TLSA Queries . . . . . . . . . . . . . . . . . . . . . . 5
	5. TLS Checks for TLSA and SRV Records . . . . . . . . . . . . . 5		5. TLS Checks for TLSA and SRV Records . . . . . . . . . . . . . 6
	6. Guidance for Application Protocols . . . . . . . . . . . . . 6		6. Guidance for Application Protocols . . . . . . . . . . . . . 6
	7. Guidance for Server Operators . . . . . . . . . . . . . . . . 6		7. Guidance for Server Operators . . . . . . . . . . . . . . . . 7
	8. Internationalization Considerations . . . . . . . . . . . . . 7		8. Internationalization Considerations . . . . . . . . . . . . . 7
	9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7		9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7
	10. Security Considerations . . . . . . . . . . . . . . . . . . . 7		10. Security Considerations . . . . . . . . . . . . . . . . . . . 8
	10.1. Mixed Security Status . . . . . . . . . . . . . . . . . 7		10.1. Mixed Security Status . . . . . . . . . . . . . . . . . 8
	10.2. A Service Domain Trusts its Servers . . . . . . . . . . 7		10.2. A Service Domain Trusts its Servers . . . . . . . . . . 8
	10.3. Certificate Subject Name Matching . . . . . . . . . . . 8		10.3. Certificate Subject Name Matching . . . . . . . . . . . 8
	10.4. Deliberate Omissions . . . . . . . . . . . . . . . . . . 8		11. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 9
	11. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 8
	12. References . . . . . . . . . . . . . . . . . . . . . . . . . 9		12. References . . . . . . . . . . . . . . . . . . . . . . . . . 9
	12.1. Normative References . . . . . . . . . . . . . . . . . . 9		12.1. Normative References . . . . . . . . . . . . . . . . . . 9
	12.2. Informative References . . . . . . . . . . . . . . . . . 10		12.2. Informative References . . . . . . . . . . . . . . . . . 10
	Appendix A. Example . . . . . . . . . . . . . . . . . . . . . . 10		Appendix A. Mail Example . . . . . . . . . . . . . . . . . . . . 10
	Appendix B. Rationale . . . . . . . . . . . . . . . . . . . . . 10		Appendix B. XMPP Example . . . . . . . . . . . . . . . . . . . . 10
	Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 11		Appendix C. Rationale . . . . . . . . . . . . . . . . . . . . . 11
			Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 12
	1. Introduction		1. Introduction
	The base DANE specification [RFC6698] describes how to use TLSA		The base DANE specification [RFC6698] describes how to use TLSA
	resource records in the DNS to associate a server's host name with		resource records in the DNS to associate a server's host name with
	its TLS certificate. The association is secured using DNSSEC. That		its TLS certificate. The association is secured using DNSSEC. That
	document "only relates to securely associating certificates for TLS		document "only relates to securely associating certificates for TLS
	and DTLS with host names" (see the last paragraph of section 1.2 of		and DTLS with host names" (see the last paragraph of section 1.2 of
	[RFC6698]).		[RFC6698]).
	skipping to change at page 3, line 44 ¶		skipping to change at page 3, line 46 ¶
	[RFC2119].		[RFC2119].
	3. Relation between SRV and MX records		3. Relation between SRV and MX records
	For the purpose of this specification (to avoid cluttering the		For the purpose of this specification (to avoid cluttering the
	description with special cases) we treat each MX record ([RFC5321]		description with special cases) we treat each MX record ([RFC5321]
	section 5) as being equivalent to an SRV record [RFC2782] with		section 5) as being equivalent to an SRV record [RFC2782] with
	corresponding fields copied from the MX record and the remaining		corresponding fields copied from the MX record and the remaining
	fields having fixed values as follows:		fields having fixed values as follows:
	Service - smtp		Table 1: SRV Fields and MX Equivalents
			+---------------+-----------------------------+
	Proto - tcp		| DNS SRV Field | Equivalent MX Value |
			+---------------+-----------------------------+
	Name - MX owner name (mail domain)		| Service | smtp |
			+---------------+-----------------------------+
	TTL - MX TTL		| Proto | tcp |
	Class - MX Class		+---------------+-----------------------------+
			| Name | MX owner name (mail domain) |
	Priority - MX Priority		+---------------+-----------------------------+
			| TTL | MX TTL |
	Weight - 0		+---------------+-----------------------------+
			| Class | MX Class |
	Port - 25		+---------------+-----------------------------+
			| Priority | MX Priority |
	Target - MX Target		+---------------+-----------------------------+
			| Weight | 0 |
			+---------------+-----------------------------+
			| Port | 25 |
			+---------------+-----------------------------+
			| Target | MX Target |
			+---------------+-----------------------------+
	Thus we can treat the following MX record as if it were the SRV		Thus we can treat the following MX record as if it were the SRV
	record shown below:		record shown below:
	example.com. 86400 IN MX 10 mx.example.net.		example.com. 86400 IN MX 10 mx.example.net.
	_smtp._tcp.example.com. 86400 IN SRV 10 0 25 mx.example.net.		_smtp._tcp.example.com. 86400 IN SRV 10 0 25 mx.example.net.
	Other details that are specific to SMTP are described in		Other details that are specific to SMTP are described in
	[I-D.ietf-dane-smtp-with-dane].		[I-D.ietf-dane-smtp-with-dane].
	skipping to change at page 4, line 37 ¶		skipping to change at page 5, line 4 ¶
	When the client makes an SRV query, a successful result will be a		When the client makes an SRV query, a successful result will be a
	list of one or more SRV records (or possibly a chain of CNAME / DNAME		list of one or more SRV records (or possibly a chain of CNAME / DNAME
	aliases referring to such a list).		aliases referring to such a list).
	For this specification to apply, all of these DNS RRsets MUST be		For this specification to apply, all of these DNS RRsets MUST be
	"secure" according to DNSSSEC validation ([RFC4033] section 5). In		"secure" according to DNSSSEC validation ([RFC4033] section 5). In
	the case of aliases, the whole chain MUST be secure as well as the		the case of aliases, the whole chain MUST be secure as well as the
	ultimate target. (This corresponds to the AD bit being set in the		ultimate target. (This corresponds to the AD bit being set in the
	response(s) - see [RFC4035] section 3.2.3.)		response(s) - see [RFC4035] section 3.2.3.)
	If they are not all secure, this protocol has not been fully		If they are not all secure, this protocol has not been fully
	deployed. The client SHOULD fall back to its non-DNSSEC non-DANE		deployed. The client SHOULD fall back to its non-DNSSEC non-DANE
	behavior. (This corresponds to the AD bit being unset.)		behavior. (This corresponds to the AD bit being unset.)
	If any of the responses is "bogus" according to DNSSEC validation,		If any of the responses is "bogus" according to DNSSEC validation,
	the client MUST abort. (This usually corresponds to a "server		the client MUST abort. (This usually corresponds to a "server
	failure" response.)		failure" response.)
	In the successful case, the client now has an authentic list of		In the successful case, the client now has an authentic list of
	server host names with weight and priority values. It performs		server host names with weight and priority values. It performs
	server ordering and selection using the weight and priority values		server ordering and selection using the weight and priority values
	without regard to the presence or absence of DNSSEC or TLSA records.		without regard to the presence or absence of DNSSEC or TLSA records.
	It takes note of the DNSSEC validation status of the SRV response for		It takes note of the DNSSEC validation status of the SRV response for
	use when checking certificate names (see Section 5).		use when checking certificate names (see Section 5).
	4.2. TLSA Queries		4.2. TLSA Queries
	This sub-section applies to each server host name individually,		If the SRV response was insecure or indeterminate, the client MUST
	provided the SRV response was secure according to DNSSEC validation.		NOT perform any TLSA queries. If the SRV response is secure
			according to DNSSEC validation, the client performs a TLSA query for
			each SRV target as describes in this section.
			For each SRV target host name, if the response to the address (A or
			AAAA) query is insecure or indeterminate, the client MUST NOT perform
			a TLSA query for that target; the TLSA a query will most likely fail.
	The client SHALL construct the TLSA query name as described in		The client SHALL construct the TLSA query name as described in
	[RFC6698] section 3, based on fields from the SRV record: the port		[RFC6698] section 3, based on fields from the SRV record: the port
	from the SRV RDATA, the protocol from the SRV query name, and the		from the SRV RDATA, the protocol from the SRV query name, and the
	TLSA base domain set to the SRV target host name.		TLSA base domain set to the SRV target host name.
	For example, the following SRV record leads to the TLSA query shown		For example, the following SRV record leads to the TLSA query shown
	below:		below:
	_imap._tcp.example.com. 86400 IN SRV 10 0 143 imap.example.net.		_imap._tcp.example.com. 86400 IN SRV 10 0 143 imap.example.net.
	skipping to change at page 5, line 48 ¶		skipping to change at page 6, line 20 ¶
	When connecting to a server, the client MUST use TLS if the responses		When connecting to a server, the client MUST use TLS if the responses
	to the SRV and TLSA queries were "secure" as described above. If the		to the SRV and TLSA queries were "secure" as described above. If the
	client received zero usable TLSA certificate associations, it SHALL		client received zero usable TLSA certificate associations, it SHALL
	validate the server's TLS certificate using the normal PKIX rules		validate the server's TLS certificate using the normal PKIX rules
	[RFC5280] or protocol-specific rules (e.g., following [RFC6125])		[RFC5280] or protocol-specific rules (e.g., following [RFC6125])
	without further input from the TLSA records. If the client received		without further input from the TLSA records. If the client received
	one or more usable TLSA certificate associations, it SHALL process		one or more usable TLSA certificate associations, it SHALL process
	them as described in [RFC6698] section 2.1.		them as described in [RFC6698] section 2.1.
	The client uses the DNSSEC validation status of the SRV query in its		If a usable TLSA record with Certificate Usage "3" matches the TLS
	server certificate identity checks. (The TLSA validation status does		server's certificate, or public key for the certificate, all other
	not affect the server certificate identity checks.) It SHALL use the		validation and verification checks MAY be ignored (e.g., reference
			identifier, key usage, expiration, issuance, etc.).
			Otherwise, the client uses the DNSSEC validation status of the SRV
			query in its server certificate identity checks. It SHOULD use the
	Server Name Indication extension (TLS SNI) [RFC6066] or its		Server Name Indication extension (TLS SNI) [RFC6066] or its
	functional equivalent in the relevant application protocol (e.g., in		functional equivalent in the relevant application protocol (e.g., in
	XMPP [RFC6120] this is the the 'to' address of the initial stream		XMPP [RFC6120] this is the the 'to' address of the initial stream
	header). The preferred name SHALL be chosen as follows, and the		header). The preferred name SHALL be chosen as follows, and the
	client SHALL verify the identity asserted by the server's certificate		client SHALL verify the identity asserted by the server's certificate
	according to [RFC6125] section 6, using a list of reference		according to [RFC6125] section 6, using a list of reference
	identifiers constructed as follows. (Note again that in RFC 6125 the		identifiers constructed as follows. (Note again that in RFC 6125 the
	terms "source domain" and "derived domain" refer to the same things		terms "source domain" and "derived domain" refer to the same things
	as "service domain" and "target host name" in this document.)		as "service domain" and "target host name" in this document.)
	skipping to change at page 6, line 26 ¶		skipping to change at page 7, line 4 ¶
	SRV is secure: The reference identifiers SHALL include both the		SRV is secure: The reference identifiers SHALL include both the
	service domain and the SRV target host name. The target host name		service domain and the SRV target host name. The target host name
	is the preferred name for TLS SNI or its equivalent.		is the preferred name for TLS SNI or its equivalent.
	(In the latter case, the client will accept either identity so that		(In the latter case, the client will accept either identity so that
	it is compatible with servers that do and do not support this		it is compatible with servers that do and do not support this
	specification.)		specification.)
	6. Guidance for Application Protocols		6. Guidance for Application Protocols
	Separate documents describe how to apply this specification to		Separate documents describe how to apply this specification to
	particular application protocols. If you are writing such as		particular application protocols. If you are writing such as
	document the following points ought to be covered:		document the following points ought to be covered:
	o Fallback logic in the event of bogus replies and the like.		o Fallback logic in the event of bogus replies and the like.
	o Compatibility with clients that do not support SRV lookups.		o Compatibility with clients that do not support SRV lookups.
	7. Guidance for Server Operators		7. Guidance for Server Operators
	In order to support this specification, server software MUST		To conform to this specification, the published SRV records and
	implement the TLS Server Name Indication extension (TLS SNI)		subsequent address (A, AAAA) records MUST be secured with DNSSEC.
	[RFC6066] (or its functional equivalent in the relevant application		There SHOULD also be at least one TLSA record published that
	protocol) for selecting the appropriate certificate.		authenticates the server's certificate. Except for Certificate Usage
			"3", the certificate authenticated by the TLSA record(s) MUST contain
			a reference identifier that matches:
	A server that supports TLS and is the target of an SRV record MUST		o the service domain name (the "source domain" in [RFC6125] terms,
	have a TLS certificate that authenticates the SRV query domain (i.e.		which is the SRV query domain); and/or
	the service domain, or "source domain" in [RFC6125] terms). This is
	necessary for clients that cannot perform DNSSEC validation. This
	certificate MUST be the default that is presented if the client does
	not use TLS SNI or its functional equivalent.
	In order to support this specification, the server SHOULD also have a		o the server host name (the "derived domain" in [RFC6125] terms,
	certificate that authenticates the SRV target domain (e.g., the mail		which is the SRV target).
	server hostname). This can be done using a multi-name certificate or
	by using the client's TLS SNI or its functional equivalent to select
	the appropriate certificate. The server's TLSA record SHOULD
	correspond to this certificate.
	Note: In some application protocols, there are old non-SRV clients		Servers that support multiple service domains (i.e., multi-tenant)
	that expect a server's TLS certificate to authenticate its host name;		can implement Server Name Identifier (TLS SNI) [RFC6066] or its
	they are also unlikely to support SNI. This means that servers for		functional equivalent to determine which certificate to offer.
	old clients need a different default certificate from servers that		Clients that do not support this specification will indicate a
	are the targets of SRV records. If the server does not have a		preference for the service domain name, while clients that support
	certificate that authenticates all relevant names, it is necessary to		this specification will indicate the server host name. However, the
	segregate old and new clients. This can be done by using different		server determines what certificate to present in the TLS handshake;
	target hosts or non-standard ports in the SRV targets. (The latter		e.g., the presented certificate might only authenticate the server
	avoids the need for additional certificates.)		host name.
	8. Internationalization Considerations		8. Internationalization Considerations
	If any of the DNS queries are for an internationalized domain name,		If any of the DNS queries are for an internationalized domain name,
	then they need to use the A-label form [RFC5890].		then they need to use the A-label form [RFC5890].
	9. IANA Considerations		9. IANA Considerations
	No IANA action is required.		No IANA action is required.
	skipping to change at page 8, line 4 ¶		skipping to change at page 8, line 22 ¶
	not break the service. Different levels of deployment are likely if		not break the service. Different levels of deployment are likely if
	a service domain has a third-party fallback server, for example.		a service domain has a third-party fallback server, for example.
	The SRV and MX sorting rules are unchanged; in particular they have		The SRV and MX sorting rules are unchanged; in particular they have
	not been altered in order to prioritize secure servers over insecure		not been altered in order to prioritize secure servers over insecure
	servers. If a site wants to be secure it needs to deploy this		servers. If a site wants to be secure it needs to deploy this
	protocol completely; a partial deployment is not secure and we make		protocol completely; a partial deployment is not secure and we make
	no special effort to support it.		no special effort to support it.
	10.2. A Service Domain Trusts its Servers		10.2. A Service Domain Trusts its Servers
	By signing their zone with DNSSEC, service domain operators		By signing their zone with DNSSEC, service domain operators
	implicitly instruct their clients to check their server TLSA records.		implicitly instruct their clients to check their server TLSA records.
	This implies another point in the trust relationship between service		This implies another point in the trust relationship between service
	domain holders and their server operators. Most of the setup		domain holders and their server operators. Most of the setup
	requirements for this protocol fall on the server operator:		requirements for this protocol fall on the server operator:
	installing a TLS certificate with the correct name, and publishing a		installing a TLS certificate with the correct name, and publishing a
	TLSA record under that name. If these are not correct then		TLSA record under that name. If these are not correct then
	connections from TLSA-aware clients might fail.		connections from TLSA-aware clients might fail.
	10.3. Certificate Subject Name Matching		10.3. Certificate Subject Name Matching
	Section 4 of the TLSA specification [RFC6698] leaves the details of		Section 4 of the TLSA specification [RFC6698] leaves the details of
	checking names in certificates to higher level application protocols,		checking names in certificates to higher level application protocols,
	though it suggests the use of [RFC6125].		though it suggests the use of [RFC6125].
	Name checking might appear to be unnecessary, since DNSSEC provides a		Name checks are not necessary if the matching TLSA record is of
	secure binding between the server name and the TLSA record, which in		Certificate Usage "3". Because such a record identifies the specific
	turn authenticates the certificate. However this latter step can be		certificate (or public key of the certificate), additional checks are
	indirect, via a chain of certificates. A usage=0 TLSA record only		superfluous and potentially conflicting.
	authenticates the CA that issued the certificate, and third parties
	can obtain certificates from the same CA.
	Therefore this specification says that a client needs to check
	whether the server's certificate matches the server host name, to
	ensure that the certificate was issued by the CA to the server that
	the client is connecting to. The client always performs this check
	regardless of the TLSA usage, to simplify implementation and so that
	this specification is less likely to need updating when new TLSA
	usages are added.
	10.4. Deliberate Omissions
	We do not specify that clients check the DNSSEC state of the server		Otherwise, while DNSSEC provides a secure binding between the server
	address records. This is not necessary since the certificate checks		name and the TLSA record, and the TLSA record provides a binding to a
	ensure that the client has connected to the correct server. (The		certificate, this latter step can be indirect via a chain of
	address records will normally have the same security state as the		certificates. For example, a Certificate Usage "0" TLSA record only
	TLSA records, but they can differ if there are CNAME or DNAME		authenticates the CA that issued the certificate, and third parties
	indirections.)		can obtain certificates from the same CA. Therefore, clients need to
			check whether the server's certificate matches one of the expected
			reference identifiers to ensure the certificate was issued by the CA
			to the server the client expects.
	11. Acknowledgements		11. Acknowledgements
	Thanks to Mark Andrews for arguing that authenticating the server		Thanks to Mark Andrews for arguing that authenticating the server
	host name is the right thing, and that we ought to rely on DNSSEC to		host name is the right thing, and that we ought to rely on DNSSEC to
	secure the SRV / MX lookup. Thanks to James Cloos, Ned Freed, Olafur		secure the SRV / MX lookup. Thanks to James Cloos, Viktor Dukhovni,
	Gudmundsson, Paul Hoffman, Phil Pennock, Hector Santos, Jonas		Ned Freed, Olafur Gudmundsson, Paul Hoffman, Phil Pennock, Hector
	Schneider, and Alessandro Vesely for helpful suggestions.		Santos, Jonas Schneider, and Alessandro Vesely for helpful
			suggestions.
	12. References		12. References
	12.1. Normative References		12.1. Normative References
	[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate		[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
	Requirement Levels", BCP 14, RFC 2119, March 1997.		Requirement Levels", BCP 14, RFC 2119, March 1997.
	[RFC2782] Gulbrandsen, A., Vixie, P., and L. Esibov, "A DNS RR for		[RFC2782] Gulbrandsen, A., Vixie, P., and L. Esibov, "A DNS RR for
	specifying the location of services (DNS SRV)", RFC 2782,		specifying the location of services (DNS SRV)", RFC 2782,
	skipping to change at page 10, line 8 ¶		skipping to change at page 10, line 15 ¶
	(PKIX) Certificates in the Context of Transport Layer		(PKIX) Certificates in the Context of Transport Layer
	Security (TLS)", RFC 6125, March 2011.		Security (TLS)", RFC 6125, March 2011.
	[RFC6698] Hoffman, P. and J. Schlyter, "The DNS-Based Authentication		[RFC6698] Hoffman, P. and J. Schlyter, "The DNS-Based Authentication
	of Named Entities (DANE) Transport Layer Security (TLS)		of Named Entities (DANE) Transport Layer Security (TLS)
	Protocol: TLSA", RFC 6698, August 2012.		Protocol: TLSA", RFC 6698, August 2012.
	12.2. Informative References		12.2. Informative References
	[I-D.ietf-dane-smtp-with-dane]		[I-D.ietf-dane-smtp-with-dane]
	Dukhovni, V. and W. Hardaker, "(DANE) TLSA records.",		Dukhovni, V. and W. Hardaker, "SMTP security via
	draft-ietf-dane-smtp-with-dane (work in progress),		opportunistic DANE TLS", draft-ietf-dane-smtp-with-dane-05
	November 2013.		(work in progress), February 2014.
	[I-D.ietf-xmpp-dna]		[I-D.ietf-xmpp-dna]
	Saint-Andre, P. and M. Miller, "Domain Name Associations		Saint-Andre, P. and M. Miller, "Domain Name Associations
	(DNA) in the Extensible Messaging and Presence Protocol		(DNA) in the Extensible Messaging and Presence Protocol
	(XMPP)", draft-ietf-xmpp-dna-04 (work in progress),		(XMPP)", draft-ietf-xmpp-dna-05 (work in progress),
	October 2013.		February 2014.
	Appendix A. Example		Appendix A. Mail Example
	In the following, most of the DNS resource data is elided for		In the following, most of the DNS resource data is elided for
	simplicity.		simplicity.
	; mail domain		; mail domain
	example.com. MX 1 mx.example.net.		example.com. MX 1 mx.example.net.
	example.com. RRSIG MX ...		example.com. RRSIG MX ...
	; SMTP server host name		; SMTP server host name
	mx.example.net. A 192.0.2.1		mx.example.net. A 192.0.2.1
			mx.example.net. RRSIG A ...
	mx.example.net. AAAA 2001:db8:212:8::e:1		mx.example.net. AAAA 2001:db8:212:8::e:1
			mx.example.net. RRSIG ...
	; TLSA resource record		; TLSA resource record
	_25._tcp.mx.example.net. TLSA ...		_25._tcp.mx.example.net. TLSA ...
	_25._tcp.mx.example.net. RRSIG TLSA ...		_25._tcp.mx.example.net. RRSIG TLSA ...
	Mail for addresses at example.com is delivered by SMTP to		Mail for addresses at example.com is delivered by SMTP to
	mx.example.net. Connections to mx.example.net port 25 that use		mx.example.net. Connections to mx.example.net port 25 that use
	STARTTLS will get a server certificate that authenticates the name		STARTTLS will get a server certificate that authenticates the name
	mx.example.net.		mx.example.net.
	Appendix B. Rationale		Appendix B. XMPP Example
			In the following, most of the DNS resource data is elided for
			simplicity.
			; XMPP domain
			_xmpp-client.example.com. SRV 1 0 5222 im.example.net.
			_xmpp-clientexample.com. RRSIG SRV ...
			; XMPP server host name
			im.example.net. A 192.0.2.3
			im.example.net. RRSIG A ...
			im.example.net. AAAA 2001:db8:212:8::e:4
			im.example.net. RRSIG AAAA ...
			; TLSA resource record
			_5222._tcp.im.example.net. TLSA ...
			_5222._tcp.im.example.net. RRSIG TLSA ...
			Mail for addresses at example.com is delivered by SMTP to
			mx.example.net. Connections to mx.example.net port 25 that use
			STARTTLS will get a server certificate that authenticates the name
			mx.example.net.
			Appendix C. Rationale
	The long-term goal of this specification is to settle on TLS		The long-term goal of this specification is to settle on TLS
	certificates that verify the server host name rather than the service		certificates that verify the server host name rather than the service
	domain, since this is more convenient for servers hosting multiple		domain, since this is more convenient for servers hosting multiple
	domains (so-called "multi-tenanted environments") and scales up more		domains (so-called "multi-tenanted environments") and scales up more
	easily to larger numbers of service domains.		easily to larger numbers of service domains.
	There are a number of other reasons for doing it this way:		There are a number of other reasons for doing it this way:
	o The certificate is part of the server configuration, so it makes		o The certificate is part of the server configuration, so it makes
	skipping to change at page 12, line 14 ¶		skipping to change at page 13, line 4 ¶
	Tony Finch		Tony Finch
	University of Cambridge Computing Service		University of Cambridge Computing Service
	New Museums Site		New Museums Site
	Pembroke Street		Pembroke Street
	Cambridge CB2 3QH		Cambridge CB2 3QH
	ENGLAND		ENGLAND
	Phone: +44 797 040 1426		Phone: +44 797 040 1426
	Email: dot@dotat.at		Email: dot@dotat.at
	URI: http://dotat.at/		URI: http://dotat.at/
	Matthew Miller		Matthew Miller
	Cisco Systems, Inc.		Cisco Systems, Inc.
	1899 Wynkoop Street, Suite 600		1899 Wynkoop Street, Suite 600
	Denver, CO 80202		Denver, CO 80202
	USA		USA
	Email: mamille2@cisco.com		Email: mamille2@cisco.com
	Peter Saint-Andre		Peter Saint-Andre
	Cisco Systems, Inc.		&yet
	1899 Wynkoop Street, Suite 600
	Denver, CO 80202
	USA
	Email: psaintan@cisco.com		Email: ietf@stpeter.im
End of changes. 31 change blocks.
	101 lines changed or deleted		126 lines changed or added
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