Internet DRAFT - draft-ietf-ipsecme-ikev1-algo-to-historic
draft-ietf-ipsecme-ikev1-algo-to-historic
Network P. Wouters, Ed.
Internet-Draft Aiven
Updates: 8221, 8247 (if approved) 19 December 2022
Intended status: Standards Track
Expires: 22 June 2023
Deprecation of IKEv1 and obsoleted algorithms
draft-ietf-ipsecme-ikev1-algo-to-historic-09
Abstract
Internet Key Exchange version 1 (IKEv1) has been deprecated and its
specification in RFC2407, RFC2408 and RFC2409 have been moved to
Historic status. This document updates RFC 8221 and RFC 8247 to
reflect the usage guidelines of old algorithms that are associated
with IKEv1, and are not specified or commonly implemented for IKEv2.
This document further updates the IANA IKEv2 Transform Type
registries to add a Status column where deprecation status can be
listed.
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
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on 22 June 2023.
Copyright Notice
Copyright (c) 2022 IETF Trust and the persons identified as the
document authors. All rights reserved.
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
and restrictions with respect to this document. Code Components
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extracted from this document must include Revised BSD License text as
described in Section 4.e of the Trust Legal Provisions and are
provided without warranty as described in the Revised BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Requirements Language . . . . . . . . . . . . . . . . . . . . 3
3. RFC2407, RFC2408 and RFC2409 are Historic . . . . . . . . . . 3
4. IKEv1 feature equivalents for IKEv2 . . . . . . . . . . . . . 4
4.1. IKEv2 postquantum support . . . . . . . . . . . . . . . . 4
4.2. IKEv2 Labeled IPsec support . . . . . . . . . . . . . . . 4
4.3. IKEv2 Group SA / Multicast support . . . . . . . . . . . 4
5. Deprecating obsolete algorithms . . . . . . . . . . . . . . . 4
6. Security Considerations . . . . . . . . . . . . . . . . . . . 4
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 6
8.1. Normative References . . . . . . . . . . . . . . . . . . 6
8.2. Informative References . . . . . . . . . . . . . . . . . 6
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 8
1. Introduction
IKEv1 has been moved to Historic status. IKEv1 [RFC2409] and its
related documents for ISAKMP [RFC2408] and IPsec DOI [RFC2407] were
obsoleted by IKEv2 [RFC4306] in December 2005. The latest version of
IKEv2 at the time of writing was published in 2014 in [RFC7296]. The
Internet Key Exchange (IKE) version 2 has replaced version 1 over 15
years ago. IKEv2 has now seen wide deployment and provides a full
replacement for all IKEv1 functionality. No new modifications or new
algorithms have been accepted for IKEv1 for at least a decade. IKEv2
addresses various issues present in IKEv1, such as IKEv1 being
vulnerable to amplification attacks.
Algorithm implementation requirements and usage guidelines for IKEv2
[RFC8247] and ESP/AH [RFC8221] gives guidance to implementors but
limits that guidance to avoid broken or weak algorithms. These two
RFCs do not deprecate algorithms that have aged and are not in use,
but leave these algorithms in a state of "MAY be used" by not
mentioning them. This document deprecates those unmentioned
algorithms that are no longer advised but for which there are no
known attacks resulting in their earlier deprecation.
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2. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in BCP
14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
3. RFC2407, RFC2408 and RFC2409 are Historic
IKEv1 is deprecated. Systems running IKEv1 should be upgraded and
reconfigured to run IKEv2. Systems that support IKEv1 but not IKEv2
are most likely also unsuitable candidates for continued operation:
* IKEv1 development ceased over a decade ago and no new work will
happen. This poses the risk of unmaintained code in an otherwise
supported product which can result in security vulnerabilities.
* A number of IKEv1 systems have reached their End of Life and
therefor will never be patched by the vendor if a vulnerability is
found.
* There are vendors that still provide updates for their equipment
that supports IKEv1 and IKEv2, but have "frozen" their IKEv1
implementation. Such users might not be aware that they are
running unmaintained code with its associated security risks.
* IKEv1 systems can be abused for packet amplification attacks, as
documented in the Security Bulletin [CVE-2016-5361].
* Great strides have been made in cryptography since IKEv1
development ceased. While some modern cryptographic algorithms
were added to IKEv1, interoperability concerns mean that the
defacto algorithms negotiated by IKEv1 will consist of dated or
deprecated algorithms like AES-CBC, SHA1, and Diffie-Hellman
groups 1 or 2. IKEv2 provides state-of-the-art suite of
cryptographic algorithms that IKEv1 lacks.
IKEv2 is a more secure protocol than IKEv1. For example, IKEv2
offers more modern cryptographic primitives, proper defense against
denial of service attacks, improved authentication via EAP methods,
PAKE support and is actively worked on with respect to defending
against quantum computer attacks.
IKEv1-only systems should be upgraded or replaced by systems
supporting IKEv2. IKEv2 implementations SHOULD NOT directly import
IKEv1 configurations without updating the cryptographic algorithms
used.
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4. IKEv1 feature equivalents for IKEv2
A few notable IKEv1 features are not present in the IKEv2 core
specification [RFC7296] but are available for IKEv2 via an additional
specification:
4.1. IKEv2 postquantum support
IKEv1 and its way of using Preshared Keys (PSKs) protects against
quantum computer based attacks. IKEv2 updated its use of PSK to
improve the error reporting, but at the expense of post-quantum
security. If post-quantum security is required, these systems should
be migrated to use IKEv2 Postquantum Preshared Keys (PPK) [RFC8784]
4.2. IKEv2 Labeled IPsec support
Some IKEv1 implementations support Labeled IPsec, a method to
negotiate an additional Security Context selector to the SPD, but
this method was never standardized in IKEv1. Those IKEv1 systems
that require Labeled IPsec should migrate to an IKEv2 system
supporting Labeled IPsec as specified in
[draft-ietf-ipsecme-labeled-ipsec].
4.3. IKEv2 Group SA / Multicast support
The Group Domain of Interpretation (GDOI, [RFC6407]) protocol, based
on IKEv1 defines the support for Multicast Group SAs. For IKEv2,
this work is currently in progress via [draft-ietf-ipsecme-g-ikev2]
5. Deprecating obsolete algorithms
This document deprecates the following algorithms:
* Encryption Algorithms: RC5, IDEA, CAST, Blowfish, and the
unspecified 3IDEA, ENCR_DES_IV64 and ENCR_DES_IV32
* PRF Algorithms: the unspecified PRF_HMAC_TIGER
* Integrity Algorithms: HMAC-MD5-128
* Diffie-Hellman groups: none
6. Security Considerations
There are only security benefits by deprecating IKEv1 for IKEv2.
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The deprecated algorithms have long been in disuse and are no longer
actively deployed or researched. It presents an unknown security
risk that is best avoided. Additionally, these algorithms not being
supported in implementations simplifies those implementations and
reduces the accidental use of these deprecated algorithms through
misconfiguration or downgrade attacks.
7. IANA Considerations
This document instructs IANA to insert the following line at the top
of the Notes section of the 'Internet Key Exchange (IKE) Attributes'
registry and the '"Magic Numbers" for ISAKMP Protocol' registry: All
registries listed below have been closed, see RFCxxxx. [Note to RFC
Editor: change RFCxxx to this document's RFC number]
This document further instructs IANA to add an additional Status
column to the IKEv2 Transform Type registries and mark the following
entries as DEPRECATED:
Transform Type 1 - Encryption Algorithm IDs
Number Name Status
------ --------------- ------
1 ENCR_DES_IV64 DEPRECATED [this document]
2 ENCR_DES DEPRECATED [RFC8247]
4 ENCR_RC5 DEPRECATED [this document]
5 ENCR_IDEA DEPRECATED [this document]
6 ENCR_CAST DEPRECATED [this document]
7 ENCR_BLOWFISH DEPRECATED [this document]
8 ENCR_3IDEA DEPRECATED [this document]
9 ENCR_DES_IV32 DEPRECATED [this document]
Figure 1
Transform Type 2 - Pseudorandom Function Transform IDs
Number Name Status
------ ------------ ----------
1 PRF_HMAC_MD5 DEPRECATED [RFC8247]
3 PRF_HMAC_TIGER DEPRECATED [this document]
Figure 2
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Transform Type 3 - Integrity Algorithm Transform IDs
Number Name Status
------ ----------------- ----------
1 AUTH_HMAC_MD5_96 DEPRECATED [RFC8247]
3 AUTH_DES_MAC DEPRECATED [RFC8247]
4 AUTH_KPDK_MD5 DEPRECATED [RFC8247]
6 AUTH_HMAC_MD5_128 DEPRECATED [this document]
7 AUTH_HMAC_SHA1_160 DEPRECATED [this document]
Figure 3
Transform Type 4 - Diffie Hellman Group Transform IDs
Number Name Status
------ ---------------------------- ----------
1 768-bit MODP Group DEPRECATED [RFC8247]
22 1024-bit MODP Group with
160-bit Prime Order Subgroup DEPRECATED [RFC8247]
Figure 4
All entries not mentioned here should receive no value in the new
Status field.
8. References
8.1. Normative References
[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>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
[RFC8247] Nir, Y., Kivinen, T., Wouters, P., and D. Migault,
"Algorithm Implementation Requirements and Usage Guidance
for the Internet Key Exchange Protocol Version 2 (IKEv2)",
RFC 8247, DOI 10.17487/RFC8247, September 2017,
<https://www.rfc-editor.org/info/rfc8247>.
8.2. Informative References
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[CVE-2016-5361]
National Institute of Science and Technology (NIST),
"National Vulnerability Database - CVE-2016-5361", 16 June
2016, <https://nvd.nist.gov/vuln/detail/CVE-2016-5361>.
[draft-ietf-ipsecme-g-ikev2]
Smyslov, V. and B. Weis, "Group Key Management using
IKEv2", Work in Progress, Internet-Draft, draft-ietf-
ipsecme-g-ikev2, 11 January 2021,
<https://www.ietf.org/archive/id/draft-ietf-ipsecme-
g-ikev2-03.txt>.
[draft-ietf-ipsecme-labeled-ipsec]
Wouters, P. and S. Prasad, "Labeled IPsec Traffic Selector
support for IKEv2", Work in Progress, Internet-Draft,
draft-ietf-ipsecme-labeled-ipsec, 25 October 2021,
<https://tools.ietf.org/id/draft-ietf-ipsecme-labeled-
ipsec-06.txt>.
[RFC2407] Piper, D., "The Internet IP Security Domain of
Interpretation for ISAKMP", RFC 2407,
DOI 10.17487/RFC2407, November 1998,
<https://www.rfc-editor.org/info/rfc2407>.
[RFC2408] Maughan, D., Schertler, M., Schneider, M., and J. Turner,
"Internet Security Association and Key Management Protocol
(ISAKMP)", RFC 2408, DOI 10.17487/RFC2408, November 1998,
<https://www.rfc-editor.org/info/rfc2408>.
[RFC2409] Harkins, D. and D. Carrel, "The Internet Key Exchange
(IKE)", RFC 2409, DOI 10.17487/RFC2409, November 1998,
<https://www.rfc-editor.org/info/rfc2409>.
[RFC4306] Kaufman, C., Ed., "Internet Key Exchange (IKEv2)
Protocol", RFC 4306, DOI 10.17487/RFC4306, December 2005,
<https://www.rfc-editor.org/info/rfc4306>.
[RFC6407] Weis, B., Rowles, S., and T. Hardjono, "The Group Domain
of Interpretation", RFC 6407, DOI 10.17487/RFC6407,
October 2011, <https://www.rfc-editor.org/info/rfc6407>.
[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>.
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[RFC8221] Wouters, P., Migault, D., Mattsson, J., Nir, Y., and T.
Kivinen, "Cryptographic Algorithm Implementation
Requirements and Usage Guidance for Encapsulating Security
Payload (ESP) and Authentication Header (AH)", RFC 8221,
DOI 10.17487/RFC8221, October 2017,
<https://www.rfc-editor.org/info/rfc8221>.
[RFC8784] Fluhrer, S., Kampanakis, P., McGrew, D., and V. Smyslov,
"Mixing Preshared Keys in the Internet Key Exchange
Protocol Version 2 (IKEv2) for Post-quantum Security",
RFC 8784, DOI 10.17487/RFC8784, June 2020,
<https://www.rfc-editor.org/info/rfc8784>.
Author's Address
Paul Wouters (editor)
Aiven
Email: paul.wouters@aiven.io
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