< draft-hardie-privsec-metadata-insertion-01.txt		draft-hardie-privsec-metadata-insertion-02.txt >
	Network Working Group T. Hardie, Ed.		Network Working Group T. Hardie, Ed.
	Internet-Draft March 07, 2016		Internet-Draft March 20, 2016
	Intended status: Informational		Intended status: Informational
	Expires: September 8, 2016		Expires: September 19, 2016
	Design considerations for Metadata Insertion		Design considerations for Metadata Insertion
	draft-hardie-privsec-metadata-insertion-01		draft-hardie-privsec-metadata-insertion-02
	Abstract		Abstract
	The IAB has published [RFC7624] in response to several revelations of		The IAB has published [RFC7624] in response to several revelations of
	pervasive attack on Internet communications. In this document we		pervasive attack on Internet communications. In this document we
	consider the implications of protocol designs which associate		consider the implications of protocol designs which associate
	metadata with encrypted flows.		metadata with encrypted flows.
	In particular, we assert that designs which do so by explicit actions		In particular, we assert that designs which do so by explicit actions
	of the end system are preferable to designs in which middleboxes		of the end system are preferable to designs in which middleboxes
	insert them.		insert them.
	Status of This Memo		Status of this Memo
	This Internet-Draft is submitted in full conformance with the		This Internet-Draft is submitted in full conformance with the
	provisions of BCP 78 and BCP 79.		provisions of BCP 78 and BCP 79.
	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 September 8, 2016.		This Internet-Draft will expire on September 19, 2016.
	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/
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	publication of this document. Please review these documents		Please review these documents carefully, as they describe your rights
	carefully, as they describe your rights and restrictions with respect		and restrictions with respect to this document. Code Components
	to this document. Code Components extracted from this document must		extracted from this document must include Simplified BSD License text
	include Simplified BSD License text as described in Section 4.e of		as described in Section 4.e of the Trust Legal Provisions and are
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	described in the Simplified BSD License.
	Table of Contents		Table of Contents
	1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2		1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 2
	2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 2		2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 2
	3. Design patterns . . . . . . . . . . . . . . . . . . . . . . . 4		3. Design patterns . . . . . . . . . . . . . . . . . . . . . . . 3
	4. Advice . . . . . . . . . . . . . . . . . . . . . . . . . . . 4		3.1. Forward-for in Forwarded HTTP Extension . . . . . . . . . 4
	5. Deployment considerations . . . . . . . . . . . . . . . . . . 5		3.2. IP Address Propagation in DNS Requests . . . . . . . . . . 4
	6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6		4. Advice . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
	7. Security Considerations . . . . . . . . . . . . . . . . . . . 6		5. Deployment considerations . . . . . . . . . . . . . . . . . . 5
	8. Contributors {Contributors} . . . . . . . . . . . . . . . . . 6		6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6
	9. References . . . . . . . . . . . . . . . . . . . . . . . . . 6		7. Security Considerations . . . . . . . . . . . . . . . . . . . 6
	9.1. Normative References . . . . . . . . . . . . . . . . . . 6		8. Contributors {Contributors} . . . . . . . . . . . . . . . . . 6
	9.2. Informative References . . . . . . . . . . . . . . . . . 7		9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 6
	Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 8		9.1. Normative References . . . . . . . . . . . . . . . . . . . 6
			9.2. Informative References . . . . . . . . . . . . . . . . . . 7
			Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 8
	1. Introduction		1. Introduction
	To ensure that the Internet can be trusted by users, it is necessary		To ensure that the Internet can be trusted by users, it is necessary
	for the Internet technical community to address the vulnerabilities		for the Internet technical community to address the vulnerabilities
	exploited in the attacks document in [RFC7258] and the threats		exploited in the attacks document in [RFC7258] and the threats
	described in [RFC7624]. The goal of this document is to address a		described in [RFC7624]. The goal of this document is to address a
	common design pattern which emerges from the increase in encryption:		common design pattern which emerges from the increase in encryption:
	explicit association of metadata which would previously have been		explicit association of metadata which would previously have been
	inferred from the plaintext protocol.		inferred from the plaintext protocol.
	2. Terminology		2. Terminology
	This document makes extensive use of standard security and privacy		This document makes extensive use of standard security and privacy
	terminology; see [RFC4949] and [RFC6973]. Terms used from [RFC6973]		terminology; see [RFC4949] and [RFC6973]. Terms used from [RFC6973]
	include Eavesdropper, Observer, Initiator, Intermediary, Recipient,		include Eavesdropper, Observer, Initiator, Intermediary, Recipient,
	Attack (in a privacy context), Correlation, Fingerprint, Traffic		Attack (in a privacy context), Correlation, Fingerprint, Traffic
	Analysis, and Identifiability (and related terms). In addition, we		Analysis, and Identifiability (and related terms). In addition, we
	use a few terms that are specific to the attacks discussed in this		use a few terms that are specific to the attacks discussed in this
	document. Note especially that "passive" and "active" below do not		document. Note especially that "passive" and "active" below do not
	refer to the effort used to mount the attack; a "passive attack" is		refer to the effort used to mount the attack; a "passive attack" is
	any attack that accesses a flow but does not modify it, while an		any attack that accesses a flow but does not modify it, while an
	"active attack" is any attack that modifies a flow. Some passive		"active attack" is any attack that modifies a flow. Some passive
	attacks involve active interception and modifications of devices,		attacks involve active interception and modifications of devices,
	rather than simple access to the medium. The introduced terms are:		rather than simple access to the medium. The introduced terms are:
	Pervasive Attack: An attack on Internet communications that makes		Pervasive Attack: An attack on Internet communications that makes use
	use of access at a large number of points in the network, or		of access at a large number of points in the network, or otherwise
	otherwise provides the attacker with access to a large amount of		provides the attacker with access to a large amount of Internet
	Internet traffic; see [RFC7258].		traffic; see [RFC7258].
	Passive Pervasive Attack: An eavesdropping attack undertaken by a		Passive Pervasive Attack: An eavesdropping attack undertaken by a
	pervasive attacker, in which the packets in a traffic stream		pervasive attacker, in which the packets in a traffic stream
	between two endpoints are intercepted, but in which the attacker		between two endpoints are intercepted, but in which the attacker
	does not modify the packets in the traffic stream between two		does not modify the packets in the traffic stream between two
	endpoints, modify the treatment of packets in the traffic stream		endpoints, modify the treatment of packets in the traffic stream
	(e.g. delay, routing), or add or remove packets in the traffic		(e.g. delay, routing), or add or remove packets in the traffic
	stream. Passive pervasive attacks are undetectable from the		stream. Passive pervasive attacks are undetectable from the
	endpoints. Equivalent to passive wiretapping as defined in		endpoints. Equivalent to passive wiretapping as defined in
	[RFC4949]; we use an alternate term here since the methods		[RFC4949]; we use an alternate term here since the methods
	employed are wider than those implied by the word "wiretapping",		employed are wider than those implied by the word "wiretapping",
	including the active compromise of intermediate systems.		including the active compromise of intermediate systems.
	Active Pervasive Attack: An attack undertaken by a pervasive		Active Pervasive Attack: An attack undertaken by a pervasive
	attacker, which in addition to the elements of a passive pervasive		attacker, which in addition to the elements of a passive pervasive
	attack, also includes modification, addition, or removal of		attack, also includes modification, addition, or removal of
	packets in a traffic stream, or modification of treatment of		packets in a traffic stream, or modification of treatment of
	packets in the traffic stream. Active pervasive attacks provide		packets in the traffic stream. Active pervasive attacks provide
	more capabilities to the attacker at the risk of possible		more capabilities to the attacker at the risk of possible
	detection at the endpoints. Equivalent to active wiretapping as		detection at the endpoints. Equivalent to active wiretapping as
	defined in [RFC4949].		defined in [RFC4949].
	Observation: Information collected directly from communications by		Observation: Information collected directly from communications by an
	an eavesdropper or observer. For example, the knowledge that		eavesdropper or observer. For example, the knowledge that
	<alice@example.com> sent a message to <bob@example.com> via SMTP		<alice@example.com> sent a message to <bob@example.com> via SMTP
	taken from the headers of an observed SMTP message would be an		taken from the headers of an observed SMTP message would be an
	observation.		observation.
	Inference: Information derived from analysis of information		Inference: Information derived from analysis of information collected
	collected directly from communications by an eavesdropper or		directly from communications by an eavesdropper or observer. For
	observer. For example, the knowledge that a given web page was		example, the knowledge that a given web page was accessed by a
	accessed by a given IP address, by comparing the size in octets of		given IP address, by comparing the size in octets of measured
	measured network flow records to fingerprints derived from known		network flow records to fingerprints derived from known sizes of
	sizes of linked resources on the web servers involved, would be an		linked resources on the web servers involved, would be an
	inference.		inference.
	Collaborator: An entity that is a legitimate participant in a		Collaborator: An entity that is a legitimate participant in a
	communication, and provides information about that communication		communication, and provides information about that communication
	to an attacker. Collaborators may either deliberately or		to an attacker. Collaborators may either deliberately or
	unwittingly cooperate with the attacker, in the latter case		unwittingly cooperate with the attacker, in the latter case
	because the attacker has subverted the collaborator through		because the attacker has subverted the collaborator through
	technical, social, or other means.		technical, social, or other means.
	Key Exfiltration: The transmission of cryptographic keying material		Key Exfiltration: The transmission of cryptographic keying material
	for an encrypted communication from a collaborator, deliberately		for an encrypted communication from a collaborator, deliberately
	or unwittingly, to an attacker.		or unwittingly, to an attacker.
	Content Exfiltration: The transmission of the content of a		Content Exfiltration: The transmission of the content of a
	communication from a collaborator, deliberately or unwittingly, to		communication from a collaborator, deliberately or unwittingly, to
	an attacker.		an attacker.
	Data Minimization: With respect to protocol design, refers to the		Data Minimization: With respect to protocol design, refers to the
	practice of only exposing the minimum amount of data or metadata		practice of only exposing the minimum amount of data or metadata
	necessary for the task supported by that protocol to the other		necessary for the task supported by that protocol to the other
	endpoint(s) and/or devices along the path.		endpoint(s) and/or devices along the path.
	3. Design patterns		3. Design patterns
	One of the core mitigations for the loss of confidentiality in the		One of the core mitigations for the loss of confidentiality in the
	presence of pervasive surveillance is data minimization, which limits		presence of pervasive surveillance is data minimization, which limits
	the amount of data disclosed to those elements absolutely required to		the amount of data disclosed to those elements absolutely required to
	complete the relevant protocol exchange. When data minimization is		complete the relevant protocol exchange. When data minimization is
	in effect, some information which was previously available may be		in effect, some information which was previously available may be
	removed from specific protocol exchanges. The information may be		removed from specific protocol exchanges. The information may be
	removed explicitly (by a browser suppressing cookies during private		removed explicitly (by a browser suppressing cookies during private
	modes, as an example) or by other means. As noted in [RFC7624], some		modes, as an example) or by other means. As noted in [RFC7624], some
	topologies which aggregate or alter the network path also acted to		topologies which aggregate or alter the network path also act to
	reduce the ease with which metadata is available to eavesdroppers.		reduce the ease with which metadata is available to eavesdroppers.
	In some cases, other actors within a protocol context will continue		In some cases, other actors within a protocol context will continue
	to have access to the information which has been thus withdrawn from		to have access to the information which has been thus withdrawn from
	specific protocol exchanges. If those actors attach the information		specific protocol exchanges. If those actors attach the information
	as metadata to those protocol exchange, the confidentiality effect of		as metadata to those protocol exchange, the confidentiality effect of
	data minimization is lost.		data minimization is lost.
	The restoration of information is particularly tempting for systems		The restoration of information is particularly tempting for systems
	whose primary function is not to provide confidentiality. A proxy		whose primary function is not to provide confidentiality. A proxy
	providing compression, for example, may wish to restore the identity		providing compression, for example, may wish to restore the identity
	of the requesting party; similarly a VPN system used to provide		of the requesting party; similarly a VPN system used to provide
	channel security may believe that origin IP should be restored.		channel security may believe that origin IP should be restored.
	Actors considering restoring metadata may believe that they		Actors considering restoring metadata may believe that they
	understand the relevant privacy considerations or believe that,		understand the relevant privacy considerations or believe that,
	because the primary purpose of the service was not privacy-related,		because the primary purpose of the service was not privacy-related,
	none exist. Examples of this design pattern include [RFC7239] and		none exist. Examples of this design pattern include "Forward-for"
	[I-D.ietf-dnsop-edns-client-subnet].		described in [RFC7239] and anointing DNS queries with originating
			network information as described in [I-D.ietf-dnsop-edns-client-
			subnet].
			3.1. Forward-for in Forwarded HTTP Extension
			[RFC7239] defines an HTTP header extension that seeks to add back
			certain network metadata that can be lost in the process of proxying
			a connection. The Forwarded-for extension allows a proxy to include
			the originating IP address as part of the HTTP request. While there
			are many types of HTTP proxies, some proxies seek to specifically
			disassociate the origin IP address from the request, and adding back
			this metadata without some explicit action of the user may
			unwittingly expose metadata that users are specifically seeking to
			protect through the use of such a proxy.
			3.2. IP Address Propagation in DNS Requests
			[I-D.ietf-dnsop-edns-client-subnet] describes and EDNS0 extension
			that can propagate the IP address of the originating DNS query
			through the DNS hierarchy of Recursive Resolvers to Authoritative
			Nameservers. Many Authoritative Nameservers will tailor their
			responses based on the IP address of the query, to provide a response
			that is network-topologically more "close" to the query IP address.
			Increasingly, Recursive Resolvers that clients use may not be close
			to the originating IP address, so by carrying the originating query
			IP address through to the Authoritative Nameserver, that server can
			provide a more topologically-relevant response to the user. DNS
			privacy is a significant challenge [RFC7626] which would only be
			exacerbated by recursive resolvers no longer serving as aggregation
			points for DNS queries and instead propagating those addresses up
			through to the Authoritative Nameservers which would then be in a
			position to profile the DNS traffic they receive based on originating
			IP address.
	4. Advice		4. Advice
	Avoid this design pattern. It contributes to the overall loss of		Avoid this design pattern. It contributes to the overall loss of
	confidentiality for the Internet and trust in the Internet as a		confidentiality for the Internet and trust in the Internet as a
	medium. Do not add metadata to flows at intermediary devices unless		medium. Do not add metadata to flows at intermediary devices unless
	a positive affirmation of approval for restoration has been received		a positive affirmation of approval for restoration has been received
	from the actor whose data will be added. Instead, design the		from the actor whose data will be added. Instead, design the
	protocol so that the actor can add such metadata themselves so that		protocol so that the actor can add such metadata themselves so that
	it flows end-to-end, rather than requiring the action of other		it flows end-to-end, rather than requiring the action of other
	parties. In addition to improving privacy, this approach ensures		parties. In addition to improving privacy, this approach ensures
	consistent availability between the communicating parties, no matter		consistent availability between the communicating parties, no matter
	what path is taken.		what path is taken.
	5. Deployment considerations		5. Deployment considerations
	There are two common tensions associated with the deployment of		There are two common tensions associated with the deployment of
	systems which restore metadata. The first is the trade-off in speed		systems which restore metadata. The first is the trade-off in speed
	of deployment for different actors. The "Forward-for" method cited		of deployment for different actors. The "Forward-for" method cited
	above provides an example of this. When used with a proxy,		above provides an example of this. When used with a proxy,
	Forwarded-for restores the original identity of the requesting party,		Forwarded-for restores the original identity of the requesting party,
	thus allowing a responding server to tailor responses according to		thus allowing a responding server to tailor responses according to
	the original party's region, network, or other characteristics		the original party's region, network, or other characteristics
	associated with the identity. It would, of course, be possible for		associated with the identity. It would, of course, be possible for
	the originating client to add this data itself, using STUN [RFC5389]		the originating client to add this data itself, using STUN [RFC5389]
	or a similar mechanism to first determine the identity to declare.		or a similar mechanism to first determine the identity to declare.
	This would require, however, full specification and adoption of this		This would require, however, full specification and adoption of this
	mechanism by the end systems. It would not be available at all		mechanism by the end systems. It would not be available at all
	during this period, and would thereafter be limited to those systems		during this period, and would thereafter be limited to those systems
	skipping to change at page 6, line 17 ¶		skipping to change at page 6, line 39 ¶
	This memo makes no request of IANA.		This memo makes no request of IANA.
	7. Security Considerations		7. Security Considerations
	This memorandum describes a design pattern related emerging from		This memorandum describes a design pattern related emerging from
	responses to the attacks described in [RFC7258]. Continued use of		responses to the attacks described in [RFC7258]. Continued use of
	this design pattern lowers the impact of mitigations to that attack.		this design pattern lowers the impact of mitigations to that attack.
	8. Contributors {Contributors}		8. Contributors {Contributors}
	This document is derived in part from the work initially done on the		This document is derived in part from the work initially done on the
	Perpass mailing list and at the STRINT workshop. It has been		Perpass mailing list and at the STRINT workshop. It has been
	discussed with the IAB's Privacy and Security program, whose review		discussed with the IAB's Privacy and Security program, whose review
	is gratefully acknowledged.		is gratefully acknowledged.
	9. References		9. References
	9.1. Normative References		9.1. 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,		Requirement Levels", BCP 14, RFC 2119, March 1997.
	DOI 10.17487/RFC2119, March 1997,
	<http://www.rfc-editor.org/info/rfc2119>.
	[RFC4949] Shirey, R., "Internet Security Glossary, Version 2",		[RFC4949] Shirey, R., "Internet Security Glossary, Version 2", FYI
	FYI 36, RFC 4949, DOI 10.17487/RFC4949, August 2007,		36, RFC 4949, DOI 10.17487/RFC4949, August 2007, <http://
	<http://www.rfc-editor.org/info/rfc4949>.		www.rfc-editor.org/info/rfc4949>.
	[RFC6973] Cooper, A., Tschofenig, H., Aboba, B., Peterson, J.,		[RFC6973] Cooper, A., Tschofenig, H., Aboba, B., Peterson, J.,
	Morris, J., Hansen, M., and R. Smith, "Privacy		Morris, J., Hansen, M. and R. Smith, "Privacy
	Considerations for Internet Protocols", RFC 6973,		Considerations for Internet Protocols", RFC 6973, DOI
	DOI 10.17487/RFC6973, July 2013,		10.17487/RFC6973, July 2013, <http://www.rfc-editor.org/
	<http://www.rfc-editor.org/info/rfc6973>.		info/rfc6973>.
	[RFC7258] Farrell, S. and H. Tschofenig, "Pervasive Monitoring Is an		[RFC7258] Farrell, S. and H. Tschofenig, "Pervasive Monitoring Is an
	Attack", BCP 188, RFC 7258, DOI 10.17487/RFC7258, May		Attack", BCP 188, RFC 7258, May 2014.
	2014, <http://www.rfc-editor.org/info/rfc7258>.
	[RFC7624] Barnes, R., Schneier, B., Jennings, C., Hardie, T.,		[RFC7624] Barnes, R., Schneier, B., Jennings, C., Hardie, T.,
	Trammell, B., Huitema, C., and D. Borkmann,		Trammell, B., Huitema, C. and D. Borkmann,
	"Confidentiality in the Face of Pervasive Surveillance: A		"Confidentiality in the Face of Pervasive Surveillance: A
	Threat Model and Problem Statement", RFC 7624,		Threat Model and Problem Statement", RFC 7624, DOI
	DOI 10.17487/RFC7624, August 2015,		10.17487/RFC7624, August 2015, <http://www.rfc-editor.org/
	<http://www.rfc-editor.org/info/rfc7624>.		info/rfc7624>.
	9.2. Informative References		9.2. Informative References
	[I-D.ietf-dnsop-edns-client-subnet]		[I-D.ietf-dnsop-edns-client-subnet]
	Contavalli, C., Gaast, W., tale, t., and W. Kumari,		Contavalli, C., Gaast, W., tale, t. and W. Kumari,
	"Client Subnet in DNS Queries", draft-ietf-dnsop-edns-		"Client Subnet in DNS Queries", Internet-Draft draft-ietf-
	client-subnet-06 (work in progress), December 2015.		dnsop-edns-client-subnet-06, December 2015.
	[RFC2015] Elkins, M., "MIME Security with Pretty Good Privacy		[RFC2015] Elkins, M., "MIME Security with Pretty Good Privacy
	(PGP)", RFC 2015, DOI 10.17487/RFC2015, October 1996,		(PGP)", RFC 2015, October 1996.
	<http://www.rfc-editor.org/info/rfc2015>.
	[RFC4301] Kent, S. and K. Seo, "Security Architecture for the		[RFC4301] Kent, S. and K. Seo, "Security Architecture for the
	Internet Protocol", RFC 4301, DOI 10.17487/RFC4301,		Internet Protocol", RFC 4301, December 2005.
	December 2005, <http://www.rfc-editor.org/info/rfc4301>.
	[RFC4306] Kaufman, C., Ed., "Internet Key Exchange (IKEv2)		[RFC4306] Kaufman, C., "Internet Key Exchange (IKEv2) Protocol", RFC
	Protocol", RFC 4306, DOI 10.17487/RFC4306, December 2005,		4306, December 2005.
	<http://www.rfc-editor.org/info/rfc4306>.
	[RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security		[RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security
	(TLS) Protocol Version 1.2", RFC 5246,		(TLS) Protocol Version 1.2", RFC 5246, August 2008.
	DOI 10.17487/RFC5246, August 2008,
	<http://www.rfc-editor.org/info/rfc5246>.
	[RFC5389] Rosenberg, J., Mahy, R., Matthews, P., and D. Wing,		[RFC5389] Rosenberg, J., Mahy, R., Matthews, P. and D. Wing,
	"Session Traversal Utilities for NAT (STUN)", RFC 5389,		"Session Traversal Utilities for NAT (STUN)", RFC 5389,
	DOI 10.17487/RFC5389, October 2008,		DOI 10.17487/RFC5389, October 2008, <http://www.rfc-
	<http://www.rfc-editor.org/info/rfc5389>.		editor.org/info/rfc5389>.
	[RFC5750] Ramsdell, B. and S. Turner, "Secure/Multipurpose Internet		[RFC5750] Ramsdell, B. and S. Turner, "Secure/Multipurpose Internet
	Mail Extensions (S/MIME) Version 3.2 Certificate		Mail Extensions (S/MIME) Version 3.2 Certificate
	Handling", RFC 5750, DOI 10.17487/RFC5750, January 2010,		Handling", RFC 5750, January 2010.
	<http://www.rfc-editor.org/info/rfc5750>.
	[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, DOI 10.17487/RFC6698, August		Protocol: TLSA", RFC 6698, August 2012.
	2012, <http://www.rfc-editor.org/info/rfc6698>.
	[RFC6962] Laurie, B., Langley, A., and E. Kasper, "Certificate		[RFC6962] Laurie, B., Langley, A. and E. Kasper, "Certificate
	Transparency", RFC 6962, DOI 10.17487/RFC6962, June 2013,		Transparency", RFC 6962, June 2013.
	<http://www.rfc-editor.org/info/rfc6962>.
	[RFC7239] Petersson, A. and M. Nilsson, "Forwarded HTTP Extension",		[RFC7239] Petersson, A. and M. Nilsson, "Forwarded HTTP Extension",
	RFC 7239, DOI 10.17487/RFC7239, June 2014,		RFC 7239, DOI 10.17487/RFC7239, June 2014, <http://www
	<http://www.rfc-editor.org/info/rfc7239>.		.rfc-editor.org/info/rfc7239>.
			[RFC7626] Bortzmeyer, S., "DNS Privacy Considerations", RFC 7626,
			DOI 10.17487/RFC7626, August 2015, <http://www.rfc-
			editor.org/info/rfc7626>.
	[STRINT] S Farrell, ., "Strint Workshop Report", April 2014,		[STRINT] S Farrell, ., "Strint Workshop Report", April 2014,
	<https://www.w3.org/2014/strint/draft-iab-strint-		<https://www.w3.org/2014/strint/draft-iab-strint-
	report.html>.		report.html>.
	Author's Address		Author's Address
	Ted Hardie (editor)		Ted Hardie, editor
	Email: ted.ietf@gmail.com		Email: ted.ietf@gmail.com
End of changes. 42 change blocks.
	96 lines changed or deleted		122 lines changed or added
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