MIF J. Korhonen
Internet-Draft Broadcom Corporation
Intended status: Standards Track S. Krishnan
Expires: April 21, 2016 Ericsson
S. Gundavelli
Cisco Systems
October 19, 2015
Support for multiple provisioning domains in IPv6 Neighbor Discovery
Protocol
draft-ietf-mif-mpvd-ndp-support-02
Abstract
The MIF working group is producing a solution to solve the issues
that are associated with nodes that can be attached to multiple
networks. One part of the solution requires associating
configuration information with provisioning domains. This document
details how configuration information provided through IPv6 Neighbor
Discovery Protocol can be associated with provisioning domains.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
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This Internet-Draft will expire on April 21, 2016.
Copyright Notice
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document authors. All rights reserved.
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carefully, as they describe your rights and restrictions with respect
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 2
3. PVD Container option . . . . . . . . . . . . . . . . . . . . 3
4. PVD Identity option . . . . . . . . . . . . . . . . . . . . . 5
5. Set of allowable options . . . . . . . . . . . . . . . . . . 6
6. Security Considerations . . . . . . . . . . . . . . . . . . . 6
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 7
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 7
9.1. Normative References . . . . . . . . . . . . . . . . . . 7
9.2. Informative References . . . . . . . . . . . . . . . . . 8
Appendix A. Examples . . . . . . . . . . . . . . . . . . . . . . 8
A.1. One implicit PVD and one explicit PVD . . . . . . . . . . 8
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 10
1. Introduction
The MIF working group is producing a solution to solve the issues
that are associated with nodes that can be attached to multiple
networks based on the Multiple Provisioning Domains (MPVD)
architecture work [RFC7556]. One part of the solution requires
associating configuration information with Provisioning Domains
(PVD). This document describes an IPv6 Neighbor Discovery Protocol
(NDP) [RFC4861] mechanism for explicitly indicating provisioning
domain information along with any configuration which is associated
with that provisioning domain. The proposed mechanism uses an NDP
option that indicates the identity of the provisioning domain and
encapsulates the options that contain the configuration information
as well as any accompanying authentication/authorization information.
The solution defined in this document aligns as much as possible with
the existing IPv6 Neighbor Discovery security, namely with Secure
Neighbor Discovery (SeND) [RFC3971].
2. Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119].
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3. PVD Container option
The PVD container option (PVD_CO) is used to mark the start of the
configuration options that belong to the explicitly identified
provisioning domain. The PVD container option MUST encapsulate
exactly one PVD identity option (PVD_ID, see Section 4). The PVD
container option MAY occur multiple times in a Router Advertisement
(RA) message. In this case each PVD container MUST belong to a
different provisioning domain. The PVD container options MUST NOT be
nested. The PVD Container option is defined only for the RA and
Router Solicitation (RS) NDP messages, and intended to be only used
with IPv6 RA messages. However, if a host wants to solicit
information for a specific provisioning domain it can include the PVD
identity option into an RS message and use the PVD container to sign
the PVD identity option.
Since implementations are required to ignore any unrecognized options
[RFC4861], the backward compatibility and the reuse of existing NDP
options is implicitly enabled. Implementations that do not recognize
the PVD container option will ignore it, and any PVD container option
"encapsulated" NDP options without associating them into any
provisioning domain (since the implementation has no notion of
provisioning domains). For example, the PVD container could
"encapsulate" a Prefix Information Option (PIO), which would mark
that this certain advertised IPv6 prefix belongs and originates from
a specific provisioning domain. However, if the implementation does
not understand provisioning domains, then this specific PIO is also
skipped and not configured to the interface.
The optional security for the PVD container is based on X.509
certificates [RFC6487] and reuses mechanisms already defined for SeND
[RFC3971] [RFC6495]. However, the use of PVD containers does not
assume or depend on SeND being deployed or even implemented. The PVD
containers SHOULD be signed per PVD certificates, which provides both
integrity protection and proves that the configuration information
source is authorized for advertising the given information. See
[RFC6494] for discussion how to enable deployments where the
certificates needed to sign PVD containers belong to different
administrative domains i.e. to different provisioning domains.
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0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type=PVD_CO | Length |S| Reserved | Name Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
: :
: Key Hash (optional) :
: :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
: :
: Digital Signature (optional) :
: :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Possible zero padding to ensure 8 octets alignment |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1: PVD Container Option
Type
PVD Container; Set to TBD1.
Length
Length of the PVD_CO. The actual length depends on the number of
"encapsulated" NDP options, the length of the PVD identifier
option, and the optional Key Hash/Digital Signature/Padding.
S
Security enabled/disabled flag. If S=0 then security (signing)
of the PVD_CO is disabled. If S=1 then security (signing) is
enabled.
Name Type
Names the algorithm used to identify a specific X.509 certificate
using the method defined for the Subject Key Identifier (SKI)
extension for the X.509 certificates. The usage and the Name
Type registry aligns with the mechanism defined for SeND
[RFC6495]. Name Type values starting from 3 are supported and an
implementation MUST at least support SHA-1 (value 3). Note that
if S=0 the Name field serves no use.
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Key Hash
This field is only present when S=1. A hash of the public key
using the algorithm identified by the Name Type. The procedure
how the Key Hash is calculated is defined in [RFC3971] and
[RFC6495].
Digital Signature
This field is only present when S=1. A signature calculated over
the PVD_CO option including all option data from the beginning of
the option until to the end of the container. The procedure of
calculating the signature is identical to the one defined for
SeND [RFC3971]. During the signature calculation the contents of
the Digital Signature option MUST be treated as all zero.
Implementations MUST ensure that the PVD container option meets the 8
octets NDP option alignment requirement as described in [RFC4861].
If the PVD_CO does not contain a digital signature, then other means
to secure the integrity of the NDP message SHOULD be provided, such
as utilizing SeND. However, the security provided by SeND is for the
entire NDP message and does not allow verifying whether the sender of
the NDP message is actually authorized for the information for the
provisioning domain.
If the PVD_CO contains a signature and the verification fails, then
the whole PVD_CO, PVD_ID and other NDP options MUST be silently
ignored and the event SHOULD be logged.
4. PVD Identity option
The PVD identity option (PVD_ID) is used to explicitly identity a
provisioning domain. In an RA message the PVD identity option MUST
be and in an RS message the PVD identity option SHOULD be
encapsulated into the associated PVD container option. However, in
the RS message PVD identity options MAY be included without any PVD
container options and in this case the PVD identity options serve
only as a hint for a specific provisioning domains.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type=PVD_ID | Length | Identity ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2: PVD_ID Option
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Type
PVD identifier; Set to TBD2.
Length
Length of the PVD_ID.
Identity
The provisioning domain identity. The contents of this field is
defined in a separate document [I-D.ietf-mif-mpvd-id]. Note that
the Identity field may need to be zero padded at the tail to
meets the natural NDP option's alignment.
If the receiver of a PVD identity option does not have one (or more)
of the received ID-Type format's implemented, then all configuration
and options which are associated with the unimplemented PVD(s) MUST
be silently discarded.
5. Set of allowable options
The PVD container option MAY be used to encapsulate any allocated
IPv6 NDP options, which may appear more than once in a NDP message.
The PVD container option MUST NOT be used to encapsulate other PVD_CO
option(s).
6. Security Considerations
An attacker may attempt to modify the information provided inside the
PVD container option. These attacks can easily be prevented by using
SeND [RFC3971] or per PVD container signature that would detect any
form of tampering with the IPv6 NDP message contents.
A compromised router may advertise configuration information related
to provisioning domains it is not authorized to advertise. e.g. A
coffee shop router may provide configuration information purporting
to be from an enterprise and may try to attract enterprise related
traffic. The only real way to avoid this is that the provisioning
domain container contains embedded authentication and authorization
information from the owner of the provisioning domain. Then, this
attack can be detected by the client by verifying the authentication
and authorization information provided inside the PVD container
option after verifying its trust towards the provisioning domain
owner (e.g. a certificate with a well-known/common trust anchor).
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A compromised configuration source or an on-link attacker may try to
capture advertised configuration information and replay it on a
different link or at a future point in time. This can be avoided by
including some replay protection mechanism such as a timestamp or a
nonce inside the PVD container to ensure freshness of the provided
information. This specification does not define a replay protection
solution. Rather it is assumed that if replay protection is
required, the access network and hosts also deploy existing security
solutions such as SeND [RFC3971].
7. IANA Considerations
This document defines two new IPv6 NDP options into the "IPv6
Neighbor Discovery Option Formats" registry. Options TBD1 and TBD2
are described in Section 3 and Section 4 respectively.
8. Acknowledgements
The authors would like to thank the members of the MIF architecture
design team for their comments that led to the creation of this
draft.
9. References
9.1. Normative References
[I-D.ietf-mif-mpvd-id]
Krishnan, S., Korhonen, J., Bhandari, S., and S.
Gundavelli, "Identification of provisioning domains",
draft-ietf-mif-mpvd-id-01 (work in progress), February
2015.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>.
[RFC3971] Arkko, J., Ed., Kempf, J., Zill, B., and P. Nikander,
"SEcure Neighbor Discovery (SEND)", RFC 3971,
DOI 10.17487/RFC3971, March 2005,
<http://www.rfc-editor.org/info/rfc3971>.
[RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman,
"Neighbor Discovery for IP version 6 (IPv6)", RFC 4861,
DOI 10.17487/RFC4861, September 2007,
<http://www.rfc-editor.org/info/rfc4861>.
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[RFC6494] Gagliano, R., Krishnan, S., and A. Kukec, "Certificate
Profile and Certificate Management for SEcure Neighbor
Discovery (SEND)", RFC 6494, DOI 10.17487/RFC6494,
February 2012, <http://www.rfc-editor.org/info/rfc6494>.
[RFC6495] Gagliano, R., Krishnan, S., and A. Kukec, "Subject Key
Identifier (SKI) SEcure Neighbor Discovery (SEND) Name
Type Fields", RFC 6495, DOI 10.17487/RFC6495, February
2012, <http://www.rfc-editor.org/info/rfc6495>.
9.2. Informative References
[RFC6487] Huston, G., Michaelson, G., and R. Loomans, "A Profile for
X.509 PKIX Resource Certificates", RFC 6487,
DOI 10.17487/RFC6487, February 2012,
<http://www.rfc-editor.org/info/rfc6487>.
[RFC7556] Anipko, D., Ed., "Multiple Provisioning Domain
Architecture", RFC 7556, DOI 10.17487/RFC7556, June 2015,
<http://www.rfc-editor.org/info/rfc7556>.
Appendix A. Examples
A.1. One implicit PVD and one explicit PVD
Figure 3 shows how the NDP options are laid out in an RA for one
implicit provisioning domain and one explicit provisioning domain.
The example does not include security (and signing of the PVD
container). The assumption is the PVD identity consumes 14 octets.
The explicit provisioning domain ("starducks.example.com" in a NAI
Realm format) contains a specific PIO for 2001:db8:abad:cafe::/64 and
the MTU of 1337 octets. The implicit provisioning domain configures
a prefix 2001:db8:cafe:babe::/64 and the link MTU of 1500 octets.
There are two cases: 1) the host receiving the RA implements
provisioning domains and 2) the host does not understand provisioning
domains.
1. The host recognizes the PVD_CO and "starts" a provisioning domain
specific configuration. Security is disabled, thus there are no
Key Hash or Digital Signature fields to process. The prefix
2001:db8:abad:cafe::/64 is found and configured on the interface.
Once the PVD_ID option is located the interface prefix
configuration for 2001:db8:abad:cafe::/64 and the MTU of 1337
octets can be associated to the provisioning domain found in the
PVD_ID option.
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The rest of the options are parsed and configured into the
implicit provisioning domain since there is no encapsulating
provisioning domain. The interface is configured with prefix
2001:db8:cafe:babe::/64. The implicit provisioning domain uses
the link MTU of 1500 octets, whereas the "starducks.example.com"
provisioning domain uses the MTU of 1337 octets (this means when
packets are sourced using 2001:db8:abad:cafe::/64 prefix the link
MTU is different than when sourcing packets using
2001:db8:cafe:babe::/64 prefix).
2. The host ignores the PVD_CO (including the PVD_ID and other
options) and ends up configuring one prefix on its interface (
2001:db8:cafe:babe::/64) with a link MTU of 1500 octets.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 134 | 0 | Checksum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Cur Hop Limit |0|1| Reserved | Router Lifetime |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reachable Time |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Retrans Timer |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ <+
| Type=PVD_CO | 10 |0| Reserved | 0 | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 0 | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 3 | 4 | 64 |1|1| Reserved1 | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Valid Lifetime | P
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ V
| Preferred Lifetime | D
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved2 | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 2001:db8:abad:cafe:: ~ |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| Type=PVD_ID | 4 | id-type=4 | 21 | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
~ "starducks.example.com",'\0','\0','\0','\0','\0','\0','\0' | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 5 | 1 | Reserved | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 1337 | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ <+
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| 3 | 4 | Prefix Length |1|1| Reserved1 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Valid Lifetime |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Preferred Lifetime |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved2 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 2001:db8:cafe:babe:: ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 5 | 1 | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 1500 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3: An RA with one implicit PVD and one explicit PVD
Authors' Addresses
Jouni Korhonen
Broadcom Corporation
3151 Zanker Road
San Jose, CA 95134
USA
Email: jouni.nospam@gmail.com
Suresh Krishnan
Ericsson
8400 Decarie Blvd.
Town of Mount Royal, QC
Canada
Phone: +1 514 345 7900 x42871
Email: suresh.krishnan@ericsson.com
Sri Gundavelli
Cisco Systems
170 West Tasman Drive
San Jose, CA 95134
USA
Email: sgundave@cisco.com
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