IKEv2 negotiation for Bound End-to-End Tunnel (BEET) mode ESP
draft-antony-ipsecme-iekv2-beet-mode-03
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| Document | Type | Active Internet-Draft (individual) | |
|---|---|---|---|
| Authors | Antony Antony , Steffen Klassert | ||
| Last updated | 2024-11-06 | ||
| Replaces | draft-antony-ipsecme-beet-mode | ||
| RFC stream | (None) | ||
| Intended RFC status | (None) | ||
| Formats | |||
| Stream | Stream state | (No stream defined) | |
| Consensus boilerplate | Unknown | ||
| RFC Editor Note | (None) | ||
| IESG | IESG state | I-D Exists | |
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| Send notices to | (None) |
draft-antony-ipsecme-iekv2-beet-mode-03
IPSECME Working Group A. Antony
Internet-Draft S. Klassert
Intended status: Standards Track secunet
Expires: 10 May 2025 6 November 2024
IKEv2 negotiation for Bound End-to-End Tunnel (BEET) mode ESP
draft-antony-ipsecme-iekv2-beet-mode-03
Abstract
This document specifies a new Notify Message Type Payload for the
Internet Key Exchange Protocol Version 2 (IKEv2), to negotiate IPsec
ESP Bound End-to-End Tunnel (BEET) mode. BEET mode combines the
benefits of tunnel mode with reduced overhead, making it suitable for
applications requiring minimalistic end-to-end tunnels, mobility
support, and multi-address multi-homing capabilities. The
introduction of the USE_BEET_MODE Notify Message enables the
negotiation and establishment of BEET mode security associations.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
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This Internet-Draft will expire on 10 May 2025.
Copyright Notice
Copyright (c) 2024 IETF Trust and the persons identified as the
document authors. All rights reserved.
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This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents (https://trustee.ietf.org/
license-info) in effect on the date of publication of this document.
Please review these documents carefully, as they describe your rights
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Background . . . . . . . . . . . . . . . . . . . . . . . 3
1.2. Requirements Language . . . . . . . . . . . . . . . . . . 3
2. IKEv2 Negotiation . . . . . . . . . . . . . . . . . . . . . . 3
2.1. USE_BEET_MODE Notify Message Payload . . . . . . . . . . 3
3. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4
4. Security Considerations . . . . . . . . . . . . . . . . . . . 4
5. Implementation Status . . . . . . . . . . . . . . . . . . . . 4
5.1. Linux XFRM . . . . . . . . . . . . . . . . . . . . . . . 5
5.2. strongSwan . . . . . . . . . . . . . . . . . . . . . . . 5
5.3. iproute2 . . . . . . . . . . . . . . . . . . . . . . . . 6
6. Acknowledgment . . . . . . . . . . . . . . . . . . . . . . . 6
7. Normative References . . . . . . . . . . . . . . . . . . . . 6
8. Informative References . . . . . . . . . . . . . . . . . . . 7
Appendix A. Additional Stuff . . . . . . . . . . . . . . . . . . 8
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 8
1. Introduction
The Bound End-to-End Tunnel (BEET) mode, as specified in Appendix B
of [RFC7402], offers an optimized approach for deploying IP Security
(IPsec), [RFC4301], using Encapsulating Security Payload (ESP)
[RFC4303] for end-to-end use cases. It combines the advantages of
Tunnel and Transport modes specified in [RFC7296], while minimizing
their overhead for end-to-end use cases.
The [RFC7402]does not specify necessary code points to negotiate a
ESP BEET mode SA using the Internet Key Exchange Protocol Version 2
(IKEv2) [RFC7296]. This document fills this gap by introducing a new
Notify Message Status Type, USE_BEET_MODE, to facilitate the
negotiation and establishment of BEET mode security associations in
IKEv2.
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1.1. Background
For over a decade, a minimalist IPsec tunnel mode, BEET, has been in
use for end-to-end security in HIP environments without IKE
negotiation, [RFC7401]. Also, in many environments, with IKE
negotiation using a private IKEv2 Notify Message Status Type
(strongSWAN).
Additionally, BEET mode ESP is valuable for low-power devices which
usually use only one end-to-end IPsec tunnel, as it reduces power
consumption [RFC9333]and complexity. In situations where devices or
IPsec connections are dedicated to a single application or transport
protocol, the use of BEET mode simplifies packet processing and
conserves energy, especially benefiting lower-powered devices.
1.2. Requirements Language
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].
2. IKEv2 Negotiation
When negotiating a Child SA using IKEv2, the initiator MUST use the
new "USE_BEET_MODE" Notify Message Status Type to request a Child SA
pair with BEET mode support. The method used is similar to how
USE_TRANSPORT_MODE is negotiated, as described in [RFC7296]
To request a BEET-mode SA on the Child SA pair, the initiator MUST
include the USE_BEET_MODE, Notify Message Status Type, when
requesting a new Child SA, either during the IKE_AUTH or the
CREATE_CHILD_SA exchanges to create a new Child SA. If the request
is accepted, the response MUST also include a USE_BEET_MODE
Notification Message Status Type. If the responder declines and does
not include the USE_BEET_MODE notification in the response, the child
SA may be established without BEET mode enabled. If this is
unacceptable to the initiator, the initiator MUST delete the child
SA.
As the use of the USE_BEET_MODE mode payload is currently only
defined for non-transport-mode tunnels, the USE_BEET_MODE
notification MUST NOT be combined with the USE_TRANSPORT
notification.
2.1. USE_BEET_MODE Notify Message Payload
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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 !
+---------------+---------------+-------------------------------+
* Payload Length - MUST be 0.
* Protocol ID (1 octet) - MUST be 0. MUST be ignored if not 0.
* SPI Size (1 octet) - MUST be 0. MUST be ignored if not 0.
3. IANA Considerations
This document defines a new "IKEv2 Notify Message Status Type" to be
added to the IANA registry [STATUSNOTIFY]
Value Notify Message Status Type Reference
----- --------------------------- ---------------
[TBD1] USE_BEET_MODE [this document]
4. Security Considerations
In this section we discuss the security properties of the BEET mode,
discussing some and point out some of its limitations [RFC3552].
There are no known new vulnerabilities that the addition of the BEET
mode to IKEv2 would create.
Since the BEET security associations have the semantics of a fixed,
point-to-point tunnel between two IP addresses, it is possible to
place one or both of the tunnel end points into other network or
nodes but those that actually "possess" the inner IP addresses, i.e.,
to implement a BEET mode proxy. However, since such usage defeats
the security benefits of combined ESP processing, as discussed in
[I-D.nikander-esp-beet-mode], the implementations SHOULD NOT support
such usage when used in combination with IKEv2; instead use IKEv2
MOBIKE to move the between networks.
5. Implementation Status
[Note to RFC Editor: Please remove this section and the reference to
[RFC6982]before publication.]
This section records the status of known implementations of the
protocol defined by this specification at the time of posting of this
Internet-Draft, and is based on a proposal described in [RFC7942].
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The description of implementations in this section is intended to
assist the IETF in its decision processes in progressing drafts to
RFCs. Please note that the listing of any individual implementation
here does not imply endorsement by the IETF. Furthermore, no effort
has been spent to verify the information presented here that was
supplied by IETF contributors. This is not intended as, and must not
be construed to be, a catalog of available implementations or their
features. Readers are advised to note that other implementations may
exist.
According to [RFC7942], "this will allow reviewers and working groups
to assign due consideration to documents that have the benefit of
running code, which may serve as evidence of valuable experimentation
and feedback that have made the implemented protocols more mature.
It is up to the individual working groups to use this information as
they see fit".
Authors are requested to add a note to the RFC Editor at the top of
this section, advising the Editor to remove the entire section before
publication, as well as the reference to [RFC7942].
5.1. Linux XFRM
Linux
Organization: Linux kernel Project
Name: Linux Kernel https://www.kernel.org/
Description: Implements BEET mode in ESP. The initial support was
added in 2006. It is widely used
Level of maturity: Stable and used for over 15 years
Licensing: GPLv2
Implementation experience: There is no support for IPv4 fragments
yet. IPv6 fragments appears to work. The BEET mode code is in
production for over a decade. And it appears stable.
Contact: https://lore.kernel.org/netdev/
5.2. strongSwan
Organization: The strongSwan Project
Name: strongSwan https://docs.strongswan.org/docs/5.9/swanctl/
swanctlConf.html
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Description: Implements IKE negotiation and ESP support for BEET
mode Linux
Level of maturity: Stable for a long time
Coverage: Implements negotiating BEET mode support in Child SA
negotiations and using it in ESP. The initial support was added
in 2006.
Licensing: GPLv2
Implementation experience strongSwan use a private Notify Message
Status Type USE_BEET_MODE (40961) for IKE. As far we know BEET is
widely used.
Contact Tobias Brunner tobias@strongswan.org
5.3. iproute2
Organization: The iproute2 Project
Name: iproute2 https://git.kernel.org/pub/scm/network/iproute2/
iproute2.git
Description: Implements BEET mode support in ESP. e.g. command
support "ip xfrm policy ... mode beet" . and "ip xfrm state ..
mode beet". The initial support was added in 2006
Level of maturity: Stable
Licensing: GPLv2
Implementation experience: TBD
Contact: https://lore.kernel.org/netdev/ or Stephen Hemminger
stephen@networkplumber.org
6. Acknowledgment
We extend our sincere gratitude to the authors and contributors who
contributed to the standardization of BEET mode. Their insights and
dedication have significantly influenced our work, as well as their
contributions to the implementation of BEET mode many years ago.
7. Normative References
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[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC7296] Kaufman, C., Hoffman, P., Nir, Y., Eronen, P., and T.
Kivinen, "Internet Key Exchange Protocol Version 2
(IKEv2)", STD 79, RFC 7296, DOI 10.17487/RFC7296, October
2014, <https://www.rfc-editor.org/info/rfc7296>.
[RFC7402] Jokela, P., Moskowitz, R., and J. Melen, "Using the
Encapsulating Security Payload (ESP) Transport Format with
the Host Identity Protocol (HIP)", RFC 7402,
DOI 10.17487/RFC7402, April 2015,
<https://www.rfc-editor.org/info/rfc7402>.
8. Informative References
[I-D.nikander-esp-beet-mode]
Nikander, P. and J. Melen, "A Bound End-to-End Tunnel
(BEET) mode for ESP", Work in Progress, Internet-Draft,
draft-nikander-esp-beet-mode-09, 5 August 2008,
<https://datatracker.ietf.org/doc/html/draft-nikander-esp-
beet-mode-09>.
[RFC3552] Rescorla, E. and B. Korver, "Guidelines for Writing RFC
Text on Security Considerations", BCP 72, RFC 3552,
DOI 10.17487/RFC3552, July 2003,
<https://www.rfc-editor.org/info/rfc3552>.
[RFC6982] Sheffer, Y. and A. Farrel, "Improving Awareness of Running
Code: The Implementation Status Section", RFC 6982,
DOI 10.17487/RFC6982, July 2013,
<https://www.rfc-editor.org/info/rfc6982>.
[RFC7401] Moskowitz, R., Ed., Heer, T., Jokela, P., and T.
Henderson, "Host Identity Protocol Version 2 (HIPv2)",
RFC 7401, DOI 10.17487/RFC7401, April 2015,
<https://www.rfc-editor.org/info/rfc7401>.
[RFC7942] Sheffer, Y. and A. Farrel, "Improving Awareness of Running
Code: The Implementation Status Section", BCP 205,
RFC 7942, DOI 10.17487/RFC7942, July 2016,
<https://www.rfc-editor.org/info/rfc7942>.
[RFC9333] Migault, D. and T. Guggemos, "Minimal IP Encapsulating
Security Payload (ESP)", RFC 9333, DOI 10.17487/RFC9333,
January 2023, <https://www.rfc-editor.org/info/rfc9333>.
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[STATUSNOTIFY]
IANA, "IKEv2 Notify Message Status Types",
<https://www.iana.org/assignments/ikev2-parameters/
ikev2-parameters.xhtml#ikev2-parameters-16>.
Appendix A. Additional Stuff
This becomes an Appendix.
Authors' Addresses
Antony Antony
secunet Security Networks AG
Email: antony.antony@secunet.com
Steffen Klassert
secunet Security Networks AG
Email: steffen.klassert@secunet.com
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