< draft-ietf-dane-srv-01.txt		draft-ietf-dane-srv-02.txt >
	DNS-Based Authentication of Named T. Finch		DNS-Based Authentication of Named T. Finch
	Entities (DANE) University of Cambridge		Entities (DANE) University of Cambridge
	Internet-Draft February 25, 2013		Internet-Draft February 25, 2013
	Intended status: Standards Track		Intended status: Standards Track
	Expires: August 29, 2013		Expires: August 29, 2013
	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-01		draft-ietf-dane-srv-02
	Abstract		Abstract
	The DANE specification [RFC6698] describes how to use TLSA resource		The DANE specification [RFC6698] 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 can use SRV records [RFC2782] to indirectly		application protocols can use SRV records [RFC2782] to indirectly
	name the server hosts for a service domain. (SMTP uses MX records		name the server hosts for a service domain. (SMTP uses MX records
	for the same purpose.) This specification gives generic instructions		for the same purpose.) This specification gives generic instructions
	for how these application protocols locate and use TLSA records.		for how these application protocols locate and use TLSA records.
	skipping to change at page 2, line 14 ¶		skipping to change at page 2, line 14 ¶
	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. DNS checks for TLSA and SRV / MX records . . . . . . . . . . . 3		2. Relation between SRV and MX records . . . . . . . . . . . . . 3
	2.1. MX records . . . . . . . . . . . . . . . . . . . . . . . . 3		3. DNS checks for TLSA and SRV records . . . . . . . . . . . . . 4
	2.2. SRV query . . . . . . . . . . . . . . . . . . . . . . . . 4		3.1. SRV query . . . . . . . . . . . . . . . . . . . . . . . . 4
	2.3. TLSA queries . . . . . . . . . . . . . . . . . . . . . . . 5		3.2. TLSA queries . . . . . . . . . . . . . . . . . . . . . . . 5
	3. TLS checks for TLSA and SRV / MX records . . . . . . . . . . . 5		4. TLS checks for TLSA and SRV records . . . . . . . . . . . . . 5
	4. Guidance for application protocols . . . . . . . . . . . . . . 6		5. Guidance for application protocols . . . . . . . . . . . . . . 6
	5. Guidance for server operators . . . . . . . . . . . . . . . . 6		6. Guidance for server operators . . . . . . . . . . . . . . . . 6
	6. Security considerations . . . . . . . . . . . . . . . . . . . 7		7. Security considerations . . . . . . . . . . . . . . . . . . . 7
	6.1. Mixed security status . . . . . . . . . . . . . . . . . . 7		7.1. Mixed security status . . . . . . . . . . . . . . . . . . 7
	6.2. A service domain trusts its servers . . . . . . . . . . . 7		7.2. A service domain trusts its servers . . . . . . . . . . . 7
	6.3. Certificate subject name matching . . . . . . . . . . . . 7		7.3. Certificate subject name matching . . . . . . . . . . . . 8
	6.4. Deliberate omissions . . . . . . . . . . . . . . . . . . . 8		7.4. Deliberate omissions . . . . . . . . . . . . . . . . . . . 8
	7. Internationalization Considerations . . . . . . . . . . . . . 8		8. Internationalization Considerations . . . . . . . . . . . . . 8
	8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8		9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8
	9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 8		10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 8
	10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 9		11. References . . . . . . . . . . . . . . . . . . . . . . . . . . 9
	10.1. Normative References . . . . . . . . . . . . . . . . . . . 9		11.1. Normative References . . . . . . . . . . . . . . . . . . . 9
	10.2. Informative References . . . . . . . . . . . . . . . . . . 9		11.2. Informative References . . . . . . . . . . . . . . . . . . 10
	Appendix A. Example . . . . . . . . . . . . . . . . . . . . . . . 10		Appendix A. Example . . . . . . . . . . . . . . . . . . . . . . . 10
	Appendix B. Rationale . . . . . . . . . . . . . . . . . . . . . . 10		Appendix B. Rationale . . . . . . . . . . . . . . . . . . . . . . 10
	Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 11		Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 11
	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
	skipping to change at page 3, line 44 ¶		skipping to change at page 3, line 44 ¶
	host name, rather than the service domain.		host name, rather than the service domain.
	Separate documents give the details that are specific to particular		Separate documents give the details that are specific to particular
	application protocols. For examples, see [I-D.ietf-dane-smtp] and		application protocols. For examples, see [I-D.ietf-dane-smtp] and
	[I-D.ietf-dane-mua].		[I-D.ietf-dane-mua].
	The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",		The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
	"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this		"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
	memo are to be interpreted as described in [RFC2119].		memo are to be interpreted as described in [RFC2119].
	2. DNS checks for TLSA and SRV / MX records		2. Relation between SRV and MX records
	2.1. 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) each MX record ([RFC5321] section 5)		description with special cases) we treat each MX record ([RFC5321]
	is treated as being equivalent to a SRV record [RFC2782] with		section 5) as being equivalent to a 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		Service - smtp
	Proto - tcp		Proto - tcp
	Name - MX owner name (mail domain)		Name - MX owner name (mail domain)
	TTL - MX TTL		TTL - MX TTL
	skipping to change at page 4, line 34 ¶		skipping to change at page 4, line 33 ¶
	For example this MX record is treated as if it were the following SRV		For example this MX record is treated as if it were the following SRV
	record:		record:
	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].		[I-D.ietf-dane-smtp].
	2.2. SRV query		3. DNS checks for TLSA and SRV records
			3.1. SRV query
	When the client makes a SRV query, a successful result will be (a		When the client makes a SRV query, a successful result will be (a
	possible chain of CNAME / DNAME aliases referring to) a list of one		possible chain of CNAME / DNAME aliases referring to) a list of one
	or more SRV records.		or more SRV records.
	For this specification to take effect, all of these DNS RRsets MUST		For this specification to take effect, all of these DNS RRsets MUST
	be "secure" according to DNSSSEC validation ([RFC4033] section 5).		be "secure" according to DNSSSEC validation ([RFC4033] section 5).
	In the case of aliases, the whole chain MUST be secure as well as the		In 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.)
	skipping to change at page 5, line 11 ¶		skipping to change at page 5, line 12 ¶
	If any of the responses is "bogus" according to DNSSEC validation the		If any of the responses is "bogus" according to DNSSEC validation the
	client MUST abort. (This usually corresponds to a "server failure"		client MUST abort. (This usually corresponds to a "server failure"
	response.)		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 Section 3).		use when checking certificate names (see section Section 4).
	2.3. TLSA queries		3.2. TLSA queries
	This sub-section applies to each server host name individually,		This sub-section applies to each server host name individually,
	provided the SRV response was secure according to DNSSEC validation.		provided the SRV response was secure according to DNSSEC validation.
	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: port from		[RFC6698] section 3, based on fields from the SRV record: port from
	the SRV RDATA, protocol from the SRV query name, and the TLSA base		the SRV RDATA, protocol from the SRV query name, and the TLSA base
	domain is the SRV target host name.		domain is the SRV target host name.
	For example this SRV record leads to the following TLSA query:		For example this SRV record leads to the following TLSA query:
	_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.
	_143._tcp.imap.example.net. IN TLSA ?		_143._tcp.imap.example.net. IN TLSA ?
	The client SHALL determine if the TLSA record(s) are usable according		The client SHALL determine if the TLSA record(s) are usable according
	to section 4.1 of [RFC6698]. This affects SRV handling as follows:		to section 4.1 of [RFC6698]. This affects SRV handling as follows:
	If the TLSA response is "secure" the client MUST use TLS when		If the TLSA response is "secure" the client MUST use TLS when
	connecting to the server. If the client receives zero usable		connecting to the server. The TLSA records are used when validating
	certificate associations, it processes TLS in the normal fashion		the server's certificate as described in section Section 4.
	without any input from the TLSA records. If the client receives one
	or more usable certificate associations, it processes them as
	described in [RFC6698].
	If the TLSA response is "insecure" or "indeterminate" the client		If the TLSA response is "insecure" or "indeterminate" the client
	SHALL proceed as if this server has no TLSA records. It MAY connect		SHALL proceed as if this server has no TLSA records. It MAY connect
	to the server with or without TLS.		to the server with or without TLS.
	If the TLSA response is "bogus" then the client MUST NOT connect to		If the TLSA response is "bogus" then the client MUST NOT connect to
	the corresponding server. (The client can still use other SRV		the corresponding server. (The client can still use other SRV
	targets.)		targets.)
	3. TLS checks for TLSA and SRV / MX records		4. TLS checks for TLSA and SRV records
	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. The		to the SRV and TLSA queries were "secure" as described above. If the
	client SHALL ensure the server's certificate passes the [RFC6698]		client received zero usable TLSA certificate associations, it SHALL
	checks if there are usable TLSA records.		validate the server's TLS certificate using the normal PKIX rules
			[RFC5280] without further input from the TLSA records. If the client
			received one or more usable TLSA certificate associations, it SHALL
			process them as described in [RFC6698] section 2.1.
	The client uses the DNSSEC validation status of the SRV query in its		The client uses the DNSSEC validation status of the SRV query in its
	server certificate identity checks. (The TLSA validation status does		server certificate identity checks. (The TLSA validation status does
	not affect the server certificate identity checks.) It MUST use the		not affect the server certificate identity checks.) It SHALL use the
	Server Name Indication extension (TLS SNI) [RFC6066] with the		Server Name Indication extension (TLS SNI) [RFC6066] with the
	preferred name chosen as follows. It SHALL verify the identity		preferred name chosen as follows. It SHALL verify the identity
	asserted by the server's certificate according to [RFC6125] section		asserted by the server's certificate according to [RFC6125] section
	6, using a list of reference identifiers constructed as follows.		6, using a list of reference identifiers constructed as follows.
	SRV is insecure or indeterminate: The reference identifiers SHALL		SRV is insecure or indeterminate: The reference identifiers SHALL
	include the service domain and MUST NOT include the SRV target		include the service domain and MUST NOT include the SRV target
	host name. The service domain is the preferred name for TLS SNI.		host name. The service domain is the preferred name for TLS SNI.
	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.		is the preferred name for TLS SNI.
	(In the latter case, the client will accept either identity so it is		(In the latter case, the client will accept either identity so that
	compatible with servers that do and do not support this		it is compatible with servers that do and do not support this
	specification.)		specification.)
	4. Guidance for application protocols		5. 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: (This section is		document the following points ought to be covered: (This section is
	currently sketchy.)		currently sketchy.)
	o SRV fallback logic? In the event of bogus replies etc.		o SRV fallback logic? In the event of bogus replies etc.
	o Compatibility with non-SRV clients.		o Compatibility with non-SRV clients.
	5. Guidance for server operators		6. Guidance for server operators
	In order to support this specification, server software MUST		In order to support this specification, server software MUST
	implement the TLS Server Name Indication extension (TLS SNI)		implement the TLS Server Name Indication extension (TLS SNI)
	[RFC6066] for selecting the appropriate certificate.		[RFC6066] for selecting the appropriate certificate.
	A server that supports TLS and is the target of a SRV record MUST		A server that supports TLS and is the target of a SRV record MUST
	have a TLS certificate that authenticates the SRV query domain (i.e.		have a TLS certificate that authenticates the SRV query domain (i.e.
	the service domain, or "source domain" in [RFC6125] terms). This is		the service domain, or "source domain" in [RFC6125] terms). This is
	necessary for clients that cannot perform DNSSEC validation. This		necessary for clients that cannot perform DNSSEC validation. This
	certificate MUST be the default that is presented if the client does		certificate MUST be the default that is presented if the client does
	skipping to change at page 7, line 21 ¶		skipping to change at page 7, line 22 ¶
	Note: In some application protocols, there are old non-SRV clients		Note: In some application protocols, there are old non-SRV clients
	that expect a server's TLS certificate to authenticate its host name;		that expect a server's TLS certificate to authenticate its host name;
	they are also unlikely to support SNI. This means that servers for		they are also unlikely to support SNI. This means that servers for
	old clients need a different default certificate from servers that		old clients need a different default certificate from servers that
	are the targets of SRV records. If the server does not have a		are the targets of SRV records. If the server does not have a
	certificate that authenticates all relevant names, it is necessary to		certificate that authenticates all relevant names, it is necessary to
	segregate old and new clients. This can be done by using different		segregate old and new clients. This can be done by using different
	target hosts or non-standard ports in the SRV targets. (The latter		target hosts or non-standard ports in the SRV targets. (The latter
	avoids the need for additional certificates.)		avoids the need for additional certificates.)
	6. Security considerations		7. Security considerations
	6.1. Mixed security status		7.1. Mixed security status
	We do not specify that clients check that all of a service domain's		We do not specify that clients check that all of a service domain's
	server host names are consistent in whether they have or do not have		server host names are consistent in whether they have or do not have
	TLSA records. This is so that partial or incremental deployment does		TLSA records. This is so that partial or incremental deployment does
	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 fall-back server, for example.		a service domain has a third-party fall-back 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.
	6.2. A service domain trusts its servers		7.2. 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.
	6.3. Certificate subject name matching		7.3. 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 checking might appear to be unnecessary, since DNSSEC provides a
	secure binding between the server name and the TLSA record, which in		secure binding between the server name and the TLSA record, which in
	turn authenticates the certificate. However this latter step can be		turn authenticates the certificate. However this latter step can be
	indirect, via a chain of certificates. A usage=0 TLSA record only		indirect, via a chain of certificates. A usage=0 TLSA record only
	authenticates the CA that issued the certificate, and third parties		authenticates the CA that issued the certificate, and third parties
	can obtain certificates from the same CA.		can obtain certificates from the same CA.
	So this specification says that clients check that the server's		So this specification says that clients check that the server's
	certificate matches the server host name, to ensure that the		certificate matches the server host name, to ensure that the
	certificate was issued by the CA to the server that the client is		certificate was issued by the CA to the server that the client is
	connecting to. The client always performs this check regardless of		connecting to. The client always performs this check regardless of
	the TLSA usage, to simplify implementation and so that this		the TLSA usage, to simplify implementation and so that this
	specification is less likely to need updating when new TLSA usages		specification is less likely to need updating when new TLSA usages
	are added.		are added.
	6.4. Deliberate omissions		7.4. Deliberate omissions
	We do not specify that clients check the DNSSEC state of the server		We do not specify that clients check the DNSSEC state of the server
	address records. This is not necessary since the certificate checks		address records. This is not necessary since the certificate checks
	ensure that the client has connected to the correct server. (The		ensure that the client has connected to the correct server. (The
	address records will normally have the same security state as the		address records will normally have the same security state as the
	TLSA records, but they can differ if there are CNAME or DNAME		TLSA records, but they can differ if there are CNAME or DNAME
	indirections.)		indirections.)
	7. 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].
	8. IANA Considerations		9. IANA Considerations
	No IANA action is required.		No IANA action is required.
	9. Acknowledgements		10. 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, Ned Freed, Olafur
	Gudmundsson, Paul Hoffman, Phil Pennock, Hector Santos, Jonas		Gudmundsson, Paul Hoffman, Phil Pennock, Hector Santos, Jonas
	Schneider, and Alessandro Vesely for helpful suggestions.		Schneider, and Alessandro Vesely for helpful suggestions.
	10. References		11. References
	10.1. Normative References
			11.1. 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,
	February 2000.		February 2000.
	[RFC4033] Arends, R., Austein, R., Larson, M., Massey, D., and S.		[RFC4033] Arends, R., Austein, R., Larson, M., Massey, D., and S.
	Rose, "DNS Security Introduction and Requirements",		Rose, "DNS Security Introduction and Requirements",
	RFC 4033, March 2005.		RFC 4033, March 2005.
	[RFC4035] Arends, R., Austein, R., Larson, M., Massey, D., and S.		[RFC4035] Arends, R., Austein, R., Larson, M., Massey, D., and S.
	Rose, "Protocol Modifications for the DNS Security		Rose, "Protocol Modifications for the DNS Security
	Extensions", RFC 4035, March 2005.		Extensions", RFC 4035, March 2005.
			[RFC5280] Cooper, D., Santesson, S., Farrell, S., Boeyen, S.,
			Housley, R., and W. Polk, "Internet X.509 Public Key
			Infrastructure Certificate and Certificate Revocation List
			(CRL) Profile", RFC 5280, May 2008.
	[RFC5321] Klensin, J., "Simple Mail Transfer Protocol", RFC 5321,		[RFC5321] Klensin, J., "Simple Mail Transfer Protocol", RFC 5321,
	October 2008.		October 2008.
	[RFC5890] Klensin, J., "Internationalized Domain Names for		[RFC5890] Klensin, J., "Internationalized Domain Names for
	Applications (IDNA): Definitions and Document Framework",		Applications (IDNA): Definitions and Document Framework",
	RFC 5890, August 2010.		RFC 5890, August 2010.
	[RFC6066] Eastlake, D., "Transport Layer Security (TLS) Extensions:		[RFC6066] Eastlake, D., "Transport Layer Security (TLS) Extensions:
	Extension Definitions", RFC 6066, January 2011.		Extension Definitions", RFC 6066, January 2011.
	[RFC6125] Saint-Andre, P. and J. Hodges, "Representation and		[RFC6125] Saint-Andre, P. and J. Hodges, "Representation and
	Verification of Domain-Based Application Service Identity		Verification of Domain-Based Application Service Identity
	within Internet Public Key Infrastructure Using X.509		within Internet Public Key Infrastructure Using X.509
	(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.
	10.2. Informative References		11.2. Informative References
	[I-D.ietf-dane-smtp]		[I-D.ietf-dane-smtp]
	Finch, T., "DNS-Based Authentication of Named Entities		Finch, T., "Secure SMTP using DNS-Based Authentication of
	(DANE) for secure SMTP", draft-ietf-dane-smtp (work in		Named Entities (DANE) TLSA records.", draft-ietf-dane-smtp
	progress), March 2013.		(work in progress), March 2013.
	[I-D.ietf-dane-mua]		[I-D.ietf-dane-mua]
	Finch, T., "DNS-Based Authentication of Named Entities		Finch, T., "Using DNS-Based Authentication of Named
	(DANE) for POP, IMAP, and message submission",		Entities (DANE) with POP, IMAP, and message submission.",
	draft-ietf-dane-mua (work in progress), March 2013.		draft-ietf-dane-mua (work in progress), March 2013.
	Appendix A. Example		Appendix A. 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 ...
End of changes. 27 change blocks.
	57 lines changed or deleted		64 lines changed or added
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