draft-ietf-6man-nd-extension-headers-01.txt		draft-ietf-6man-nd-extension-headers-02.txt
	IPv6 maintenance Working Group (6man) F. Gont		IPv6 maintenance Working Group (6man) F. Gont
	Internet-Draft SI6 Networks / UTN-FRH		Internet-Draft SI6 Networks / UTN-FRH
	Updates: 3971, 4861 (if approved) November 5, 2012		Updates: 3971, 4861 (if approved) December 10, 2012
	Intended status: Standards Track		Intended status: Standards Track
	Expires: May 9, 2013		Expires: June 13, 2013
	Security Implications of IPv6 Fragmentation with IPv6 Neighbor Discovery		Security Implications of IPv6 Fragmentation with IPv6 Neighbor Discovery
	draft-ietf-6man-nd-extension-headers-01		draft-ietf-6man-nd-extension-headers-02
	Abstract		Abstract
	This document analyzes the security implications of using IPv6		This document analyzes the security implications of using IPv6
	Extension Headers with Neighbor Discovery (ND) messages. It updates		Extension Headers with Neighbor Discovery (ND) messages. It updates
	RFC 4861 such that use of the IPv6 Fragmentation Header is forbidden		RFC 4861 such that use of the IPv6 Fragmentation Header is forbidden
	in all Neighbor Discovery messages, thus allowing for simple and		in all Neighbor Discovery messages, thus allowing for simple and
	effective counter-measures for Neighbor Discovery attacks. Finally,		effective counter-measures for Neighbor Discovery attacks. Finally,
	it discusses the security implications of using IPv6 fragmentation		it discusses the security implications of using IPv6 fragmentation
	with SEcure Neighbor Discovery (SEND), and formally updates RFC 3971		with SEcure Neighbor Discovery (SEND), and formally updates RFC 3971
	skipping to change at page 1, line 39		skipping to change at page 1, line 39
	Internet-Drafts are working documents of the Internet Engineering		Internet-Drafts are working documents of the Internet Engineering
	Task Force (IETF). Note that other groups may also distribute		Task Force (IETF). Note that other groups may also distribute
	working documents as Internet-Drafts. The list of current Internet-		working documents as Internet-Drafts. The list of current Internet-
	Drafts is at http://datatracker.ietf.org/drafts/current/.		Drafts is at http://datatracker.ietf.org/drafts/current/.
	Internet-Drafts are draft documents valid for a maximum of six months		Internet-Drafts are draft documents valid for a maximum of six months
	and may be updated, replaced, or obsoleted by other documents at any		and may be updated, replaced, or obsoleted by other documents at any
	time. It is inappropriate to use Internet-Drafts as reference		time. It is inappropriate to use Internet-Drafts as reference
	material or to cite them other than as "work in progress."		material or to cite them other than as "work in progress."
	This Internet-Draft will expire on May 9, 2013.		This Internet-Draft will expire on June 13, 2013.
	Copyright Notice		Copyright Notice
	Copyright (c) 2012 IETF Trust and the persons identified as the		Copyright (c) 2012 IETF Trust and the persons identified as the
	document authors. All rights reserved.		document authors. All rights reserved.
	This document is subject to BCP 78 and the IETF Trust's Legal		This document is subject to BCP 78 and the IETF Trust's Legal
	Provisions Relating to IETF Documents		Provisions Relating to IETF Documents
	(http://trustee.ietf.org/license-info) in effect on the date of		(http://trustee.ietf.org/license-info) in effect on the date of
	publication of this document. Please review these documents		publication of this document. Please review these documents
	skipping to change at page 2, line 16		skipping to change at page 2, line 16
	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. Traditional Neighbor Discovery and IPv6 Fragmentation . . . . 5		2. Traditional Neighbor Discovery and IPv6 Fragmentation . . . . 5
	3. SEcure Neighbor Discovery (SEND) and IPv6 Fragmentation . . . 6		3. SEcure Neighbor Discovery (SEND) and IPv6 Fragmentation . . . 6
	4. Specification . . . . . . . . . . . . . . . . . . . . . . . . 7		4. Specification . . . . . . . . . . . . . . . . . . . . . . . . 7
	5. Security Considerations . . . . . . . . . . . . . . . . . . . 8		5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8
	6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 9		6. Security Considerations . . . . . . . . . . . . . . . . . . . 9
	7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 10		7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 10
	7.1. Normative References . . . . . . . . . . . . . . . . . . . 10		8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 11
	7.2. Informative References . . . . . . . . . . . . . . . . . . 10		8.1. Normative References . . . . . . . . . . . . . . . . . . . 11
	Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 12		8.2. Informative References . . . . . . . . . . . . . . . . . . 11
			Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 13
	1. Introduction		1. Introduction
	The Neighbor Discovery Protocol (NDP) is specified in RFC 4861		The Neighbor Discovery Protocol (NDP) is specified in RFC 4861
	[RFC4861] and RFC 4862 [RFC4862]. It is used by both hosts and		[RFC4861] and RFC 4862 [RFC4862]. It is used by both hosts and
	routers. Its functions include Neighbor Discovery (ND), Router		routers. Its functions include Neighbor Discovery (ND), Router
	Discovery (RD), Address Autoconfiguration, Address Resolution,		Discovery (RD), Address Autoconfiguration, Address Resolution,
	Neighbor Unreachability Detection (NUD), Duplicate Address Detection		Neighbor Unreachability Detection (NUD), Duplicate Address Detection
	(DAD), and Redirection.		(DAD), and Redirection.
	skipping to change at page 8, line 5		skipping to change at page 8, line 5
	o Certification Path Solicitation		o Certification Path Solicitation
	Nodes SHOULD normally process the following messages when the packets		Nodes SHOULD normally process the following messages when the packets
	carrying them include an IPv6 Fragmentation Header:		carrying them include an IPv6 Fragmentation Header:
	o Certification Path Advertisement		o Certification Path Advertisement
	SEND nodes SHOULD NOT employ keys that would result in fragmented CPA		SEND nodes SHOULD NOT employ keys that would result in fragmented CPA
	messages.		messages.
	5. Security Considerations		5. IANA Considerations
			There are no IANA registries within this document. The RFC-Editor
			can remove this section before publication of this document as an
			RFC.
			6. Security Considerations
	The IPv6 Fragmentation Header can be leveraged to circumvent network		The IPv6 Fragmentation Header can be leveraged to circumvent network
	monitoring tools and current implementations of mechanisms such as		monitoring tools and current implementations of mechanisms such as
	RA-Guard [I-D.ietf-v6ops-ra-guard-implementation]. By updating the		RA-Guard [I-D.ietf-v6ops-ra-guard-implementation]. By updating the
	relevant specifications such that the IPv6 Fragment Header is not		relevant specifications such that the IPv6 Fragment Header is not
	allowed in any Neighbor Discovery messages except "Certification Path		allowed in any Neighbor Discovery messages except "Certification Path
	Advertisement", protection of local nodes against Neighbor Discovery		Advertisement", protection of local nodes against Neighbor Discovery
	attacks, and monitoring of Neighbor Discovery traffic is greatly		attacks, and monitoring of Neighbor Discovery traffic is greatly
	simplified.		simplified.
	skipping to change at page 9, line 5		skipping to change at page 10, line 5
	unless [RFC4861] is updated (as proposed in this document), Neighbor		unless [RFC4861] is updated (as proposed in this document), Neighbor
	Discovery monitoring tools (such as NDPMon [NDPMon]) would remain		Discovery monitoring tools (such as NDPMon [NDPMon]) would remain
	unreliable and trivial to circumvent by a skilled attacker.		unreliable and trivial to circumvent by a skilled attacker.
	As noted in Section 3, use of SEND could potentially result in		As noted in Section 3, use of SEND could potentially result in
	fragmented "Certification Path Advertisement" messages, thus allowing		fragmented "Certification Path Advertisement" messages, thus allowing
	an attacker to employ IPv6 fragmentation-based attacks against such		an attacker to employ IPv6 fragmentation-based attacks against such
	messages. Therefore, to the extent that is possible, such use of		messages. Therefore, to the extent that is possible, such use of
	fragmentation should be avoided.		fragmentation should be avoided.
	6. Acknowledgements		7. Acknowledgements
	The author would like to thank (in alphabetical order) Mikael		The author would like to thank (in alphabetical order) Mikael
	Abrahamsson, Ran Atkinson, Ron Bonica, Jean-Michel Combes, David		Abrahamsson, Ran Atkinson, Ron Bonica, Jean-Michel Combes, David
	Farmer, Roque Gagliano, Bob Hinden, Philip Homburg, Ray Hunter,		Farmer, Roque Gagliano, Bob Hinden, Philip Homburg, Ray Hunter,
	Arturo Servin, and Mark Smith, for providing valuable comments on		Arturo Servin, and Mark Smith, for providing valuable comments on
	earlier versions of this document.		earlier versions of this document.
	This document resulted from the project "Security Assessment of the		This document resulted from the project "Security Assessment of the
	Internet Protocol version 6 (IPv6)" [CPNI-IPv6], carried out by		Internet Protocol version 6 (IPv6)" [CPNI-IPv6], carried out by
	Fernando Gont on behalf of the UK Centre for the Protection of		Fernando Gont on behalf of the UK Centre for the Protection of
	National Infrastructure (CPNI). The author would like to thank the		National Infrastructure (CPNI). The author would like to thank the
	UK CPNI, for their continued support.		UK CPNI, for their continued support.
	7. References		8. References
	7.1. Normative References		8.1. 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.
	[RFC3971] Arkko, J., Kempf, J., Zill, B., and P. Nikander, "SEcure		[RFC3971] Arkko, J., Kempf, J., Zill, B., and P. Nikander, "SEcure
	Neighbor Discovery (SEND)", RFC 3971, March 2005.		Neighbor Discovery (SEND)", RFC 3971, March 2005.
	[RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman,		[RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman,
	"Neighbor Discovery for IP version 6 (IPv6)", RFC 4861,		"Neighbor Discovery for IP version 6 (IPv6)", RFC 4861,
	September 2007.		September 2007.
	[RFC4862] Thomson, S., Narten, T., and T. Jinmei, "IPv6 Stateless		[RFC4862] Thomson, S., Narten, T., and T. Jinmei, "IPv6 Stateless
	Address Autoconfiguration", RFC 4862, September 2007.		Address Autoconfiguration", RFC 4862, September 2007.
	7.2. Informative References		8.2. Informative References
	[RFC3756] Nikander, P., Kempf, J., and E. Nordmark, "IPv6 Neighbor		[RFC3756] Nikander, P., Kempf, J., and E. Nordmark, "IPv6 Neighbor
	Discovery (ND) Trust Models and Threats", RFC 3756,		Discovery (ND) Trust Models and Threats", RFC 3756,
	May 2004.		May 2004.
	[RFC6104] Chown, T. and S. Venaas, "Rogue IPv6 Router Advertisement		[RFC6104] Chown, T. and S. Venaas, "Rogue IPv6 Router Advertisement
	Problem Statement", RFC 6104, February 2011.		Problem Statement", RFC 6104, February 2011.
	[RFC6105] Levy-Abegnoli, E., Van de Velde, G., Popoviciu, C., and J.		[RFC6105] Levy-Abegnoli, E., Van de Velde, G., Popoviciu, C., and J.
	Mohacsi, "IPv6 Router Advertisement Guard", RFC 6105,		Mohacsi, "IPv6 Router Advertisement Guard", RFC 6105,
	February 2011.		February 2011.
	[NDPMon] "NDPMon - IPv6 Neighbor Discovery Protocol Monitor",		[NDPMon] "NDPMon - IPv6 Neighbor Discovery Protocol Monitor",
	<http://ndpmon.sourceforge.net/>.		<http://ndpmon.sourceforge.net/>.
	[ramond] "ramond", <http://ramond.sourceforge.net/>.		[ramond] "ramond", <http://ramond.sourceforge.net/>.
	[I-D.ietf-v6ops-ra-guard-implementation]		[I-D.ietf-v6ops-ra-guard-implementation]
	Gont, F., "Implementation Advice for IPv6 Router		Gont, F., "Implementation Advice for IPv6 Router
	Advertisement Guard (RA-Guard)",		Advertisement Guard (RA-Guard)",
	draft-ietf-v6ops-ra-guard-implementation-05 (work in		draft-ietf-v6ops-ra-guard-implementation-07 (work in
	progress), October 2012.		progress), November 2012.
	[CPNI-IPv6]		[CPNI-IPv6]
	Gont, F., "Security Assessment of the Internet Protocol		Gont, F., "Security Assessment of the Internet Protocol
	version 6 (IPv6)", UK Centre for the Protection of		version 6 (IPv6)", UK Centre for the Protection of
	National Infrastructure, (available on request).		National Infrastructure, (available on request).
	[Gont-DEEPSEC2011]		[Gont-DEEPSEC2011]
	Gont, "Results of a Security Assessment of the Internet		Gont, "Results of a Security Assessment of the Internet
	Protocol version 6 (IPv6)", DEEPSEC 2011 Conference,		Protocol version 6 (IPv6)", DEEPSEC 2011 Conference,
	Vienna, Austria, November 2011, <http://		Vienna, Austria, November 2011, <http://
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