Internet DRAFT - draft-dupont-ikev2-addrmgmt
draft-dupont-ikev2-addrmgmt
Network Working Group F. Dupont
Internet-Draft Point6
Expires: May 22, 2006 November 18, 2005
Address Management for IKE version 2
draft-dupont-ikev2-addrmgmt-08.txt
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Copyright Notice
Copyright (C) The Internet Society (2005).
Abstract
The current IKEv2 proposal lacks an address management feature. As
it is compatible with the NAT traversal capability, this document
specifies a complete address management with support for multi-homing
and mobility, and fulfill mobike IETF working group goals 1, 2, 3, 4,
and 6.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Goals . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.1. Simplicity, Performance and Security . . . . . . . . . . . 3
2.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . 4
2.3. Multi-homing requirements . . . . . . . . . . . . . . . . 4
2.4. Mobility requirements . . . . . . . . . . . . . . . . . . 4
3. Proposal . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.1. Kept points from/clarification to the IKEv2 draft 17 . . . 6
3.2. Minor points . . . . . . . . . . . . . . . . . . . . . . . 6
3.3. Peer address notifications . . . . . . . . . . . . . . . . 7
3.4. Explicit peer address update payload . . . . . . . . . . . 7
3.5. Open issues . . . . . . . . . . . . . . . . . . . . . . . 8
4. Security Considerations . . . . . . . . . . . . . . . . . . . 9
5. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 10
6. References . . . . . . . . . . . . . . . . . . . . . . . . . . 10
6.1. Normative References . . . . . . . . . . . . . . . . . . . 10
6.2. Informative References . . . . . . . . . . . . . . . . . . 10
Appendix A. Peer Address Notification Format . . . . . . . . . . 11
Appendix B. Peer Address Update Payload Format . . . . . . . . . 12
Appendix C. NAT Prevention Notification Format . . . . . . . . . 14
Appendix D. Return Routability Cookie Notification Format . . . . 15
Appendix E. PF_KEY version 2 SADB_X_ADDUPD . . . . . . . . . . . 15
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 17
Intellectual Property and Copyright Statements . . . . . . . . . . 18
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1. Introduction
This document proposes an address management for IKEv2 [1] for all
the IETF mobike working group goals [4] at the exception of the goal
5 (handled by [5]).
In this document, the addresses used to transport IKE messages are
named the "peer addresses" (term introduced by [6]). These peer
addresses should no more be directly or indirectly included in
identities ([7] and [8]) as it is commonly done for IKEv1.
The current IKEv2 draft [1] often makes the implicit assumption that
an address identifies a node when nodes behind a NAT can share the
same address and a node can use many different addresses. This must
be taken into account in implementations, for instance by reading
this document before writing code...
This document describes the goals of an address management for IKEv2,
including the requirements for multi-homing and mobility support
(this part will be removed as soon as the mobike requirements
document [9] is finalized), and finishes by a concrete proposal.
In this document, open questions are introduced by the word NOTE and
will be refined in a dedicated section.
2. Goals
The goals of the address management proposed in the document can be
divided in some general goals and in requirements for the three
mechanisms which can change the peer addresses.
2.1. Simplicity, Performance and Security
The address management should be as simple as possible, i.e., it
should introduce minimal additions to the current IKEv2 draft [1] and
each addition should be justified.
The performance is an important criterion. For instance, rekeying
can update the peer addresses of an IKE SA or an IPsec SA pair, but
rekeying is too expensive and a specific solution is needed.
As a security protocol, IKEv2 should get a high security level.
Unfortunately we already showed that the NAT traversal feature comes
with a security issue (the transient pseudo-NAT attack [10]).
Such problems introduced by the peer address flexibility must be
described in this document and at least be mitigated by options in
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configurations. For instance, the NAT traversal feature should never
be enabled when one knows that there can not be a NAT as today in
IPv6.
An other example of an insecure mechanism is to use the addresses in
IP headers of CREATE_CHILD_SA messages as the endpoint addresses of
the new IPsec SAs without further control on them: peer addresses
must be managed.
2.2. Terminology
The addresses of the two peers are named "peer addresses". With
other words the peer addresses are the addresses IKE runs over but
this document extends this basic definition. The primary peer
address of a peer is initialized to the address used to transport
messages of the initial exchanges, other addresses are "alternate
peer addresses".
The proxy case is the setup of transport mode IPsec SAs on the behalf
of another party, i.e., transport mode IPsec SAs where the traffic
selectors do not match the primary peer addresses.
2.3. Multi-homing requirements
In this document, the support of multi-homing is the support of nodes
with several global addresses. Some of the addresses can be "better"
than others, or "better" for some destinations. Some can, from time
to time, be unavailable.
The main requirement for the support of multi-homing is the
management of a set of peer addresses for each peer. The set can be
partially ordered or some subsets can be loosely associated with some
destinations (i.e., some subsets of the other peer address set, this
is needed when a destination address can be reached only using
particular source addresses).
For the communication between multi-addressed hosts, the support of
the proxy case can be useful because it provides an easy way to setup
transport mode IPsec SAs with different addresses from one IKE SA.
In such cases the other party is in fact the same host, this
dramatically simplifies the authorization issue.
2.4. Mobility requirements
In the context of Mobile IPv6 ([11] and for the special case of Home
Agents [12]), the interaction of Mobility and IPsec was analyzed in
another document [13]. This document assumes an IPv6 context as
Mobile IPv6 is the most powerful mobility proposal available today.
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An IPv6 mobile node is another type of multi-addressed node with:
- a care-of address in a prefix of the visited link.
The care-of address is used to route packets.
- the home address in a prefix of the home link.
The home address is used to identify the mobile node.
The care-of address is transient and usually the mobile node can not
provide a proof that it is the node using it. So it has to be
trusted and a return routability check (i.e., an enforced answer from
this address) should be used if it is not.
With a common correspondent, the mobility is transparent and there is
no reason to use another address than the home address. For
optimized schemes, without an implementation of header compression in
ESP tunnel mode (the goal 5 of mobike [4]) the choice between a
transport mode using triangular routing (IPsec can be used to verify
home address options) and a tunnel mode with routing optimization is
not clear. But this case does not add new requirement, i.e., the
home agent case includes them.
With the home agent, there are three main cases (c.f. [12]):
- The mobility signaling which is mandatory protected and raises a
specific issue in its initial phase: the IKE SA must be setup
using the care-of address as the peer address but this IKE SA is
used to build an IPsec SA pair with the home address as traffic
selector. This IPsec SA will protect the home registration which
will make the home address available. This can be considered as a
specialized proxy case.
- Other genuine communications between the home agent and the mobile
node can be covered by the proxy case support too. Note this is
the only case at the exception of signaling where mobility behaves
in a different way than a mobile IPsec VPN (so we proposed to
relax the corresponding rule in a future version of [11] and
[12]).
- The traffic relayed by the home agent through a tunnel with the
mobile node can be partially or fully protected by IPsec SA
pair(s). Encapsulation should be performed only once, including
for degenerated (but not for free) encapsulation like the home
address option or the mobility routing header.
In all cases of interaction with the home agent, the mobile node peer
address should be a care-of address. When the mobile node moves,
another care-of address is used and some SAs, including the IKE SA,
must be updated to use the new address.
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Usually the previous peer address is no more usable. In order to
avoid a trivial denial of services, a strong sequencing of updates is
required with a way to cancel possible pending updates when fast
multiple handoff happen.
The IPsec pair which protects the mobility signaling uses the home
address as its traffic selector for the mobile node. It must not be
updated at each handoff. The update mechanism must provide a fine
grain (i.e., per SA) update.
3. Proposal
The proposal for an address management in IKEv2 is spawn from the NAT
traversal mechanisms, mainly with a new peer address update payload.
But there are some points that have to be kept or clarify as they
already are in the current IKEv2 draft [1].
3.1. Kept points from/clarification to the IKEv2 draft 17
The peer addresses MUST be stable during the initial exchanges, i.e.,
the IKE_SA_INIT and IKE_AUTH exchanges MUST be transported using the
same peer address pair.
The peer addresses are used to transport messages. The reply to a
request MUST be sent to the source of the request from the
destination request, i.e., addresses and ports are reversed between
the request and its reply. There is no exception to this rule.
For tunnel mode IPsec SAs, the endpoint addresses are the primary
peer addresses. We don't propose an alternate way to specify them.
The same requirement applies to transport mode IPsec SAs at the
exception of the proxy case.
3.2. Minor points
In retransmission of requests or responses, copies of messages do not
include peer addresses. So a peer MAY retransmit an IKE message from
or to a different address.
The primary peer addresses are IKE SA parameters and are specified by
the IKE_SA_INIT exchange. Note that when NAT traversal is not
active, they are implicitly protected by the NAT_DETECTION or
NAT_PREVENTION notifications.
All the text below applies only to the case where NAT traversal is
not active. Everything relative to transport mode, including the
proxy case, is dealt with in [2].
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Return routability checks are done using an informational exchange
carrying a RR_COOKIE notification in order to get a proof the probed
peer really receives the request. Of course the reply MUST contain
the same RR_COOKIE notification than the request.
3.3. Peer address notifications
The peer address notifications are copied from the current
NAT_DETECTION_SOURCE_IP and NAT_DETECTION_DESTINATION_IP
notifications. They includes the peer source or destination address
with its family and an operation code. They MUST be in an encrypted
payload. Operations are MARK, ADD and DELETE (last two for alternate
addresses, see open issue section for the empty set one and the
delete operation on the primary peer address).
All messages after the first exchange involving an alternate peer
address MUST include at least one peer address notification for each
peer, i.e., at least one for the source and at least one for the
destination.
Such messages belong to IKE_AUTH or CREATE_CHILD_SA exchanges, or
carry the peer address update payload defined below, or are pure peer
address set management (add/delete).
They provide a cryptographically proof of no en-route alteration of
the peer addresses and enable operations on the sets of peer
addresses, i.e., change of the primary peer address of a peer,
addition to and deletion from the peer address set of a peer.
When the peer address notifications are not supported, the capability
to use an alternate peer address, and only this, is lost.
As these notifications do not transport zone indications, they MUST
NOT be used for ambiguous not-global addresses. But it is still
possible to use a not-global address in the IKE_SA_INIT exchange.
NOTE: this seems the only reasonnable common possibility and of
course in this case the not-global address is not ambiguous.
3.4. Explicit peer address update payload
A new payload has to be defined for an explicit peer address update
mechanism. We propose to copy it from the delete payload, see
Appendix B.
The new peer address update payload has strong sequencing
requirements. IKEv2 messages have a protected sequence number so the
only sequencing issues are the window of processing and pending
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exchanges. Any messages with a peer address update payload MUST be
processed in order.
When the receiver of an additin or update request has to check the
validity of a new peer address, it MAY use a return routability check
sending an informational request carrying a RR_COOKIE notification at
the new address and waiting for an answer. As informational
exchanges are protected no more is needed.
Example of a return routability check:
I ----- address update request -----> R
I <-- informational RR [Ni] request - R
I --- informational RR [Ni] reply --> R
now the responder knows the initiator should be where it claimed
to be.
I <------ address update reply ------ R
When a peer address update deletes the current primary address,
pending (i.e., to be retransmitted) requests MUST be sent to the new
address(es) even it is (they are) not yet checked.
NOTE: look at the open issue about the detection of the movement
behind a NAT.
As for the delete payload, the peer address update payload specifies
the SPIs of the IPsec and IKE SAs it applies to. But a simple way to
specify all SAs (i.e., the IKE SA and all the tunnel mode IPsec SAs
it negotiated) is needed so is provided.
An updated peer address may be in some corresponding SPD entries:
when an IPsec SA is modified, by default the SPD entry which matches
the traffic selector SHOULD be accordingly modified (cf. the next
version of the IPsec architecture [3]). This behavior MAY be
disabled.
3.5. Open issues
Notification/payload/exchange: the current choice is a notification
for peer addresses (copied on NAT detection notifications) and a
payload for peer address update (copied on SA delete payload).
Interaction with NAT-T: the current choice is to avoid the case where
one peer is behind a NAT then uses NAT-T and the other peer uses
MOBIKE: in this situation NAT-T usage by both peers MUST be enforced.
Path failure detection: the proposal does not provide any dedicated
mechanism, the generic mobility or multi-homing control SHOULD be
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used instead, including for simultaneous changes.
When to perform a return routability check?: this is a policy issue,
some answers follow.
Can a peer address set be empty?: still open. Mechanisms permit
this...
New error notification for address problems: likely to be necessary.
Dead lock with too small message window?: message windows greater
than one are RECOMMENDED and the last message of windows SHOULD be
reserved to MOBIKE.
Peer address addition request from an unknown address: (here unknown
means not in the peer address set even after the processing of the
message) this is the only circumstance where a return routability
check is clearly REQUIRED:
- if it succeeds for the peer address the message MUST be accepted
- if it fails for the peer address but succeeds for the unknown
source address the peer has moved behind a NAT.
Last point: how to update the SPD entries? One possibility is to
change the PAD ([3] section 4.4.3 defining the Peer Authorization
Database) too.
4. Security Considerations
Great care was used to avoid to introduce new security threats.
The NAT traversal feature comes with a security flaw (the transient
pseudo-NAT attack [10]) which can not be easily avoid. IMHO the NAT
traversal feature should be enabled only when the presence of NATs is
likely/possible.
When the NAT traversal feature is disabled, the address of the other
peer can not be changed en-route by an attacker but the proofs the
peer is really at its address are:
- the trust in the peer
- the source address is topologically plausible
- the proof that the peer can receive messages sent to its address.
The second (a.k.a. the return routability check) works only with at
least two ot three not-trivial messages, i.e., for the initial
exchange (with the address stability requirement) and for explicit
checks. IMHO these checks SHOULD be required for a new alternate
peer address as soon as there is no proof of the address validity,
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for instance when:
- the message does not come from this address (ingress filtering
[14] can drop a message with a fake source address),
- and there is no authorization for this address.
5. Acknowledgments
The rare people in the Mobility world with IPsec interests, or in the
IPsec world with Mobility interest, should receive all thanks because
without them we (me and all the future co-authors) have given up for
a long time.
Tero Kivinen helped to improve the NAT traversal part of this
proposal. Tero and Jari Arkko proposed another form of peer address
update based on the IKE SA addresses. Pasi Eronen suggested the
NAT_PREVENTION notification.
6. References
6.1. Normative References
[1] Kaufman, C., Ed., "Internet Key Exchange (IKEv2) Protocol",
draft-ietf-ipsec-ikev2-17.txt (work in progress),
September 2004.
[2] Dupont, F., "IPsec transport mode in Mobike environments",
draft-dupont-mobike-transport-03.txt (work in progress),
October 2005.
[3] Kent, S. and K. Seo, "Security Architecture for the Internet
Protocol", draft-ietf-ipsec-rfc2401bis-06.txt (work in
progress), March 2005.
6.2. Informative References
[4] IKEv2 Mobility and Multihoming (mobike), "Charter", 2004,
<http://www.ietf.org/html.charters/mobike-charter.html>.
[5] Vilhuber, J., "IP header compression in IPsec ESP",
draft-vilhuber-hcoesp-01.txt (work in progress), July 2004.
[6] Korver, B., "The Internet IP Security PKI Profile of IKEv1/
ISAKMP, IKEv2, and PKIX",
draft-ietf-pki4ipsec-ikecert-profile-07.txt (work in progress),
November 2005.
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[7] Hoffman, P., "Adding revised identities to IKEv2",
November 2002, <Message-ID: <p05200f06b9edf48ac57b@
[165.227.249.18]>>.
[8] Kaat, M., "Overview of 1999 IAB Network Layer Workshop",
RFC 2956, October 2000.
[9] Kivinen, T. and H. Tschofenig, "Design of the MOBIKE protocol",
draft-ietf-mobike-design-04.txt (work in progress),
October 2005.
[10] Dupont, F. and J-J. Bernard, "Transient pseudo-NAT attacks or
how NATs are even more evil than you believed",
draft-dupont-transient-pseudonat-04.txt (work in progress),
June 2004.
[11] Johnson, D., Perkins, C., and J. Arkko, "Mobility Support in
IPv6", RFC 3775, June 2004.
[12] Arkko, J., Devarapalli, V., and F. Dupont, "Using IPsec to
Protect Mobile IPv6 Signaling Between Mobile Nodes and Home
Agents", RFC 3776, June 2004.
[13] Dupont, F. and W. Haddad, "How to make IPsec more mobile IPv6
friendly", draft-dupont-ipsec-mipv6-05.txt (work in progress),
February 2004.
[14] Ferguson, P. and D. Senie, "Network Ingress Filtering:
Defeating Denial of Service Attacks which employ IP Source
Address Spoofing", RFC 2827, BCP 38, May 2000.
[15] McDonald, D., Metz, C., and B. Phan, "PF_KEY Key Management
API, Version 2", RFC 2367, July 1998.
Appendix A. Peer Address Notification Format
The following diagram illustrates the content of the Peer Address
Notification:
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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
! Next Payload !C! RESERVED ! Payload Length !
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
! Protocol-ID ! SPI Size ! Notify Message Type !
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
! Address Family ! Operation !
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ Address ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1
The notification header is for IKE SA (Protocol-ID 0, SPI Size 0 and
no SPI). The Address Family is from IANA Address Family Numbers
(IPv4 is 1 and IPv6 2). The proposed names are PEER_ADDRESS_SOURCE
and PEER_ADDRESS_DESTINATION, with 248XX. Operation codes are:
- MARK (1): the peer address is marked for further operation, for
instance an peer address update: the marked address will become
the new primary peer address.
- ADD (2): add a new alternate peer address to the set.
- DELETE (3): delete an alternate peer address from the set.
Appendix B. Peer Address Update Payload Format
The next figure shows the format of the Peer Address Update Payload.
It is possible to send multiple SPIs in a Peer Address Update
payload, however, each SPI MUST be for the same protocol. Mixing of
Protocol Identifiers MUST NOT be performed in a the Peer Address
Update payload. It is permitted, however, to include multiple Peer
Address Update payloads in a single INFORMATIONAL Exchange where each
Peer Address Update payload lists SPIs for a different protocol.
Update of the IKE_SA is indicated by a Protocol_Id of 0 (IKE) but no
SPI. Update of a CHILD_SA, such as ESP or AH, will contain the
Protocol_Id of that protocol (1 for ESP, 2 for AH) and the SPI is the
SPI the sending endpoint would expect in inbound ESP or AH packets.
The following diagram illustrates the content of the Peer Address
Update Notification:
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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
! Next Payload !C! RESERVED ! Payload Length !
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
!A|O|Protocol-ID! SPI Size ! # of SPIs !
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
! !
~ Security Parameter Index(es) (SPI) ~
! !
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2
- A[ll] (1 bit) - MUST be set to one when all SAs (the IKE SA and
all tunnel mode outgoing IPsec SAs negotiated by it) are updated.
In this case the update is for the IKE-SA (Protocol-ID 0, SPI size
0, no SPI and number of SPIs 0). MUST be set to zero when an
individual SA is updated.
- O[nly] (1 bit) - MUST be set to one when the corresponding SPD
entry when it exists MUST NOT be modified. MUST be set to zero
for the default behavior: for all SPD entries matching traffic
selectors of updated IPsec SAs the peer address(es) MUST be
updated.
- Protocol_Id (6 bits) - MUST be zero for an IKE_SA, 1 for ESP, or 2
for AH.
- SPI Size (1 octet) - Length in octets of the SPI as defined by the
Protocol-Id. Zero for IKE (the SPI is got from the message
header) or four for AH or ESP.
- # of SPIs (2 octets) - The number of SPIs contained in the Peer
Address Update Notification. The size of each SPI is defined by
the SPI Size field.
- Security Parameter Index(es) (variable length) - Identifies the
specific security association(s) to delete. The lengths of these
fields are determined by the SPI Size and the number of SPIs
fields.
The C[ritical] bit MUST be set to one even a peer which does not
support Peer Address Update Payloads does not support Peer Address
Notifications too.
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ESP and AH SAs always exist in pairs, with one SA in each direction.
When an SA is updated for a peer address, both members of the pair
MUST be updated. When SAs are nested, as when data (and IP headers
if in tunnel mode) are encapsulated first with IPcomp, then with ESP,
and finally with AH between the same pair of endpoints, all of the
SAs MUST be updated together. Each endpoint MUST update the SAs it
receives on and allow the other endpoint to update the other SA in
each pair.
To update a peer address of an SA, an Informational Exchange with one
or more peer address update payloads is sent listing the SPIs (as
they would be placed in the headers of inbound packets) of the SAs to
be updated, and with a peer address notification setting the primary
peer address. The recipient MUST update the designated SAs.
Normally, the reply in the Informational Exchange will contain peer
address update payloads for the paired SAs going in the other
direction. Note there is no special case for update collision.
The proposed name is the Update (U) payload.
Appendix C. NAT Prevention Notification Format
The NAT_PREVENTION notification purpose is to protect the peer
addresses in the IKE_SA_INIT exchange without misleading the
responder, i.e., NAT_DETECTION_SOURCE_IP and
NAT_DETECTION_DESTINATION_IP do the same thing but suggest the
responder is ready to accept NAT traversal.
The NAT_PREVENTION notification SHOULD be used when NAT traversal is
not wanted and the authentication does not validate the peer address:
the default policy (cf. [6] section 3.1.1 about address ID payloads)
is to validate peer addresses but only when the ID payload is an
address and this validation may be disabled.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
! Next Payload !C! RESERVED ! Payload Length !
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
! Protocol-ID ! SPI Size ! Notify Message Type !
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ SHA-1 Hash of the Pseudo-Header ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3
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The notification header is for IKE SA (Protocol-ID 0, SPI Size 0 and
no SPI). The content is the SHA-1 hash of the transport pseudo-
header.
NOTE: there is an IPR issue over the NAT detection notifications.
Appendix D. Return Routability Cookie Notification Format
The RR_COOKIE notification layout is:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
! Next Payload !C! RESERVED ! Payload Length !
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
! Protocol-ID ! SPI Size ! Notify Message Type !
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ Cookie ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 4
The notification header is for IKE SA (Protocol-ID 0, SPI Size 0 and
no SPI). The data associated with the notification (i.e., the cookie
itself) MUST be between 16 and 64 octets in length (inclusive).
This cookie SHOULD be included in return routability probes in order
to make them unpredictable. A reply to a request carrying a
RR_COOKIE notification MUST contain a copy of it.
Appendix E. PF_KEY version 2 SADB_X_ADDUPD
This annex describes an extension to PF_KEYv2 [15] which provides a
way to ask a peer address update of an IPsec SA and all its siblings
(i.e., an update with the All flag set to one).
The format of the message is:
<base, SA(*), address(SD), new_address(SD)>
and is sent the registered socket listeners by or via the kernel. No
answer is needed because if it fails it will be done again.
New values are needed for SADB_X_ADDUPD and for
SADB_X_EXT_NEW_ADDRESS_SRC and SADB_X_EXT_NEW_ADDRESS_DST which
should have the same layout than SADB_EXT_ADDRESS_*, i.e.,
sadb_address structure.
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Internet-Draft Address Management for IKEv2 November 2005
NOTE: IKE itself needs a PF_KEYv2 extension for individual updating
of an IPsec SA.
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Internet-Draft Address Management for IKEv2 November 2005
Author's Address
Francis Dupont
Point6
c/o GET/ENST Bretagne
2 rue de la Chataigneraie
CS 17607
35576 Cesson-Sevigne Cedex
France
Fax: +33 2 99 12 70 30
Email: Francis.Dupont@enst-bretagne.fr
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Internet-Draft Address Management for IKEv2 November 2005
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