< draft-ietf-ospf-security-extension-manual-keying-03.txt		draft-ietf-ospf-security-extension-manual-keying-04.txt >
	OSPF Working Group M. Bhatia		OSPF Working Group M. Bhatia
	Internet-Draft Alcatel-Lucent		Internet-Draft Alcatel-Lucent
	Intended status: Standards Track S. Hartman		Intended status: Standards Track S. Hartman
	Expires: April 25, 2013 Painless Security		Expires: August 26, 2013 Painless Security
	D. Zhang		D. Zhang
	Huawei Technologies co., LTD.		Huawei Technologies co., LTD.
	A. Lindem		A. Lindem
	Ericsson		Ericsson
	October 22, 2012		February 22, 2013
	Security Extension for OSPFv2 when using Manual Key Management		Security Extension for OSPFv2 when using Manual Key Management
	draft-ietf-ospf-security-extension-manual-keying-03		draft-ietf-ospf-security-extension-manual-keying-04
	Abstract		Abstract
	The current OSPFv2 cryptographic authentication mechanism as defined		The current OSPFv2 cryptographic authentication mechanism as defined
	in the OSPF standards is vulnerable to both inter-session and intra-		in the OSPF standards is vulnerable to both inter-session and intra-
	session replay attacks when its uses manual keying. Additionally,		session replay attacks when its uses manual keying. Additionally,
	the existing cryptographic authentication schemes do not cover the IP		the existing cryptographic authentication schemes do not cover the IP
	header. This omission can be exploited to carry out various types of		header. This omission can be exploited to carry out various types of
	attacks.		attacks.
	skipping to change at page 1, line 47 ¶		skipping to change at page 1, line 47 ¶
	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 April 25, 2013.		This Internet-Draft will expire on August 26, 2013.
	Copyright Notice		Copyright Notice
	Copyright (c) 2012 IETF Trust and the persons identified as the		Copyright (c) 2013 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
	skipping to change at page 3, line 45 ¶		skipping to change at page 3, line 45 ¶
	neighbor. Hello packets may be reflected to cause a neighbor to		neighbor. Hello packets may be reflected to cause a neighbor to
	appear to have one-way communication. Old Database descriptions may		appear to have one-way communication. Old Database descriptions may
	be reflected in cases where the per-packet sequence numbers are		be reflected in cases where the per-packet sequence numbers are
	sufficiently divergent in order to disrupt an adjacency		sufficiently divergent in order to disrupt an adjacency
	[I-D.ietf-karp-ospf-analysis]. This is referred to as the IP layer		[I-D.ietf-karp-ospf-analysis]. This is referred to as the IP layer
	issue in [I-D.ietf-karp-threats-reqs].		issue in [I-D.ietf-karp-threats-reqs].
	[RFC2328] states that implementations MUST offer keyed MD5		[RFC2328] states that implementations MUST offer keyed MD5
	authentication. It is likely that this will be deprecated in favor		authentication. It is likely that this will be deprecated in favor
	of the stronger algorithms described in [RFC5709] in future		of the stronger algorithms described in [RFC5709] in future
	deployments [I-D.ietf-opsec-igp-crypto-requirements].		deployments [RFC6094].
	This draft proposes a simple change in the cryptographic		This draft proposes a simple change in the cryptographic
	authentication mechanism, as currently described in [RFC5709], to		authentication mechanism, as currently described in [RFC5709], to
	prevent such IP layer attacks.		prevent such IP layer attacks.
	1.1. Requirements Section		1.1. Requirements Section
	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
	document are to be interpreted as described in RFC2119 [RFC2119].		document are to be interpreted as described in RFC2119 [RFC2119].
	skipping to change at page 6, line 44 ¶		skipping to change at page 6, line 44 ¶
	Figure 7 - Extended Sequence Number Packet Extensions		Figure 7 - Extended Sequence Number Packet Extensions
	4. OSPF Packet Key Selection		4. OSPF Packet Key Selection
	This section describes how the proposed security solution selects		This section describes how the proposed security solution selects
	long-lived keys from key tables. [I-D.ietf-karp-crypto-key-table].		long-lived keys from key tables. [I-D.ietf-karp-crypto-key-table].
	Generally, a key used for OSPFv2 packet authentication should satisfy		Generally, a key used for OSPFv2 packet authentication should satisfy
	the following requirements:		the following requirements:
	o The key time period as defined by NotBefore and NotAfter must		o For packet transmission, the key validity interval as defined by
	include the current time.		SendLifeTimeStart and SendLifeTimeEnd must include the current
			time.
			o For packet reception, the key validity interval as defined by
			AcceptLifeTimeStart and AcceptLifeTimeEnd must include the current
			time.
	o The key can be used for the desired security algorithm.		o The key can be used for the desired security algorithm.
	In the remainder of this section, additional requirements for keys		In the remainder of this section, additional requirements for keys
	are enumerated for different scenarios.		are enumerated for different scenarios.
	4.1. Key Selection for Unicast OSPF Packet Transmission		4.1. Key Selection for Unicast OSPF Packet Transmission
	Assume that a router R1 tries to send a unicast OSPF packet from its		Assume that a router R1 tries to send a unicast OSPF packet from its
	interface I1 to the interface R2 of a remote router R2 using security		interface I1 to the interface R2 of a remote router R2 using security
	protocol P via interface I at time T. Firstly consider the		protocol P via interface I at time T. First, consider the
	circumstances where R1 and R2 are not connected with a virtual link.		circumstances where R1 and R2 are not connected with a virtual link.
	R1 then needs to select a long long-lived symmetric key from its key		R1 then needs to select a long long-lived symmetric key from its key
	table. Because the key should be shared by the by both R1 and R2 to		table. Because the key should be shared by the by both R1 and R2 to
	protect the communication between I1 and I2, the key should satisfy		protect the communication between I1 and I2, the key should satisfy
	the following requirements:		the following requirements:
	o The Peer field includes the router ID of R2.		o The Peers field is unused. OSPF authentiction is interface based.
	o the PeerKeyID field is not "unknown".		o The Interfaces field includes the local IP address of the
			interface for nummbered interfaces or the MIB-II [RFC1213],
			ifIndex for unnumbered interfaces.
	o The Interfaces field includes I1.		o The Direction field is either "out" or "both".
	o the Direction field is either "out" or "both".		When R1 and R2 are connected to a virtual link, the interfaces field
			must identify the virtual endpoint rather than the virtual link.
			Since there may be virtual links to the same router, the transit area
			ID must be part of the identifier. Hence, the key should satisfy the
			following requirements:
	When R1 and R2 are connected to a virtual link, the third condition		o The Peers field is unused. OSPF authentiction is interface based.
	is a little more complex. Because the virtual link can be regarded
	as an unnumbered point-to-point network, the IP address of the		o The Interfaces field includes both the virtual endpoint's OSPF
	interface actually used to send the packet (i.e., I1) is discovered		router ID and the the transit area ID for the virtual link.
	during routing table calculation. Therefore, when the system
	operator configures keys to protect the virtual link, I1 is unknown		o The Direction field is either "out" or "both".
	and can be any OSPF interface in the OSPF virtual link's transit
	area. Therefore, the key should be identified solely by the local
	and remote router IDs rather than by the interface on which the
	packet is sent. The third requirement list above should be changed
	to "the Interface field includes the router ID".
	4.2. Key Selection for Multicast OSPF Packet Transmission		4.2. Key Selection for Multicast OSPF Packet Transmission
	If a router R1 sends an OSPF packet from its interface I1 to a		If a router R1 sends an OSPF packet from its interface I1 to a
	multicast address (e.g., AllSPFRouters, AllDRouters), it needs to		multicast address (e.g., AllSPFRouters, AllDRouters), it needs to
	select a key according to the following requirements:		select a key according to the following requirements:
	o The Peer field includes the multicast address.		o The Peers field is unused. OSPF authentication is interface
			based.
	o The PeerKeyID field is "group".
	o The Interfaces field includes I1.		o The Interfaces field includes the local IP address of the
			interface for nummbered interfaces or the MIB-II [RFC1213],
			ifIndex for unnumbered interfaces.
	o The Direction field is either "out" or "both".		o The Direction field is either "out" or "both".
	4.3. Key Selection for OSPF Packet Reception		4.3. Key Selection for OSPF Packet Reception
	When Cryptographic Authentication is employed, the ID of the		When Cryptographic Authentication is used, the ID of the
	authentication key is included in the authentication field of the		authentication key is included in the authentication field of the
	OSPF packet header. Using this key ID, it is relatively easy for a		OSPF packet header. Using this key ID, it is relatively easy for a
	receiver to locate the key. The simple requirements are:		receiver to locate the key. The simple requirements are:
	o The Peer field includes the router ID of the sender.		o The interface on which the key was received is associated with the
			key's interface.
	o The PeerKeyID field includes the key ID obtained from the		o The PeerKeyName field includes the key ID obtained from the
	authentication field.		authentication field. Since OSPF keys are symmetric, the
			LocalKeyName and PeerKeyName for OSPF keys will be identical.
	o The Direction field is either "in" or "both".		o The Direction field is either "in" or "both".
	5. Mechanism to secure the IP header		5. Mechanism to secure the IP header
	This document updates the definition of Apad which is currently a		This document updates the definition of Apad which is currently a
	constant defined in [RFC5709] to the source address from the IP		constant defined in [RFC5709] to the source address from the IP
	header of the OSPFv2 protocol packet. The overall cryptographic		header of the OSPFv2 protocol packet. The overall cryptographic
	authentication process defined in [RFC5709] remains unchanged. To		authentication process defined in [RFC5709] remains unchanged. To
	reduce the potential for confusion, this section minimizes the		reduce the potential for confusion, this section minimizes the
	skipping to change at page 10, line 4 ¶		skipping to change at page 10, line 9 ¶
	7. IANA Considerations		7. IANA Considerations
	This document requests a new code point from the "OSPF Shortest Path		This document requests a new code point from the "OSPF Shortest Path
	First (OSPF) Authentication Codes" registry:		First (OSPF) Authentication Codes" registry:
	o TBD - Cryptographic Authentication with Extended Sequence Numbers.		o TBD - Cryptographic Authentication with Extended Sequence Numbers.
	The value 3 is recommended.		The value 3 is recommended.
	8. References		8. References
	8.1. Normative References		8.1. Normative References
			[I-D.ietf-karp-crypto-key-table]
			Housley, R., Polk, T., Hartman, S., and D. Zhang,
			"Database of Long-Lived Symmetric Cryptographic Keys",
			draft-ietf-karp-crypto-key-table-06 (work in progress),
			February 2013.
	[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.
	[RFC2328] Moy, J., "OSPF Version 2", STD 54, RFC 2328, April 1998.		[RFC2328] Moy, J., "OSPF Version 2", STD 54, RFC 2328, April 1998.
	[RFC5709] Bhatia, M., Manral, V., Fanto, M., White, R., Barnes, M.,		[RFC5709] Bhatia, M., Manral, V., Fanto, M., White, R., Barnes, M.,
	Li, T., and R. Atkinson, "OSPFv2 HMAC-SHA Cryptographic		Li, T., and R. Atkinson, "OSPFv2 HMAC-SHA Cryptographic
	Authentication", RFC 5709, October 2009.		Authentication", RFC 5709, October 2009.
	8.2. Informative References		8.2. Informative References
	[I-D.ietf-karp-crypto-key-table]
	Housley, R. and T. Polk, "Database of Long-Lived Symmetric
	Cryptographic Keys", draft-ietf-karp-crypto-key-table-00
	(work in progress), November 2010.
	[I-D.ietf-karp-ospf-analysis]		[I-D.ietf-karp-ospf-analysis]
	Hartman, S. and D. Zhang, "Analysis of OSPF Security		Hartman, S. and D. Zhang, "Analysis of OSPF Security
	According to KARP Design Guide",		According to KARP Design Guide",
	draft-ietf-karp-ospf-analysis-00 (work in progress),		draft-ietf-karp-ospf-analysis-06 (work in progress),
	March 2011.		May 2013.
	[I-D.ietf-karp-threats-reqs]		[I-D.ietf-karp-threats-reqs]
	Lebovitz, G., Bhatia, M., and R. White, "The Threat		Lebovitz, G., Bhatia, M., and B. Weis, "The Threat
	Analysis and Requirements for Cryptographic Authentication		Analysis and Requirements for Cryptographic Authentication
	of Routing Protocols' Transports",		of Routing Protocols' Transports",
	draft-ietf-karp-threats-reqs-02 (work in progress),		draft-ietf-karp-threats-reqs-07 (work in progress),
	April 2011.		December 2012.
	[I-D.ietf-opsec-igp-crypto-requirements]		[RFC1213] McCloghrie, K. and M. Rose, "Management Information Base
	Bhatia, M. and V. Manral, "Summary of Cryptographic		for Network Management of TCP/IP-based internets:MIB-II",
	Authentication Algorithm Implementation Requirements for		STD 17, RFC 1213, March 1991.
	Routing Protocols",
	draft-ietf-opsec-igp-crypto-requirements-04 (work in
	progress), October 2010.
	[RFC3414] Blumenthal, U. and B. Wijnen, "User-based Security Model		[RFC3414] Blumenthal, U. and B. Wijnen, "User-based Security Model
	(USM) for version 3 of the Simple Network Management		(USM) for version 3 of the Simple Network Management
	Protocol (SNMPv3)", STD 62, RFC 3414, December 2002.		Protocol (SNMPv3)", STD 62, RFC 3414, December 2002.
	[RFC4222] Choudhury, G., "Prioritized Treatment of Specific OSPF		[RFC4222] Choudhury, G., "Prioritized Treatment of Specific OSPF
	Version 2 Packets and Congestion Avoidance", BCP 112,		Version 2 Packets and Congestion Avoidance", BCP 112,
	RFC 4222, October 2005.		RFC 4222, October 2005.
	[RFC6039] Manral, V., Bhatia, M., Jaeggli, J., and R. White, "Issues		[RFC6039] Manral, V., Bhatia, M., Jaeggli, J., and R. White, "Issues
	with Existing Cryptographic Protection Methods for Routing		with Existing Cryptographic Protection Methods for Routing
	Protocols", RFC 6039, October 2010.		Protocols", RFC 6039, October 2010.
			[RFC6094] Bhatia, M. and V. Manral, "Summary of Cryptographic
			Authentication Algorithm Implementation Requirements for
			Routing Protocols", RFC 6094, February 2011.
	Authors' Addresses		Authors' Addresses
	Manav Bhatia		Manav Bhatia
	Alcatel-Lucent		Alcatel-Lucent
	Bangalore,		Bangalore,
	India		India
	Phone:		Phone:
	Email: manav.bhatia@alcatel-lucent.com		Email: manav.bhatia@alcatel-lucent.com
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