Internet DRAFT - draft-pwouters-ikev1-ipsec-graveyard
draft-pwouters-ikev1-ipsec-graveyard
Network P. Wouters, Ed.
Internet-Draft Red Hat
Updates: 7296,8221,8247 (if approved) February 21, 2021
Intended status: Standards Track
Expires: August 25, 2021
Deprecation of IKEv1 and obsoleted algorithms
draft-pwouters-ikev1-ipsec-graveyard-06
Abstract
Internet Key Exchange version 1 (IKEv1) is deprecated. Accordingly,
IKEv1 has been moved to Historic status. A number of old algorithms
that are associated with IKEv1, and not widely implemented for IKEv2
are deprecated as well. IANA is instructed to close all IKEv1
registries.
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 August 25, 2021.
Copyright Notice
Copyright (c) 2021 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 extracted from this document must
include Simplified BSD License text as described in Section 4.e of
Wouters Expires August 25, 2021 [Page 1]
Internet-Draft Deprecation of IKEv1 and some algorithms February 2021
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Requirements Language . . . . . . . . . . . . . . . . . . . . 2
3. RFC 2409 to Historic . . . . . . . . . . . . . . . . . . . . 3
4. Deprecating obsolete algorithms . . . . . . . . . . . . . . . 3
5. Security Considerations . . . . . . . . . . . . . . . . . . . 3
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 5
7.1. Normative References . . . . . . . . . . . . . . . . . . 5
7.2. Informative References . . . . . . . . . . . . . . . . . 6
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 6
1. Introduction
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. IKEv1 has been moved to Historic status, and
this document requests IANA to close all IKEv1 registries.
Algorithm implementation requirements and usage guidelines for IKEv2
[RFC8247] and ESP/AH [RFC8223] gives guidance to implementors but
limits that guidance to avoid broken or weak algorithms. It does not
deprecate algorithms that have aged and are not in use, but leave
these algorithms in a state of "MAY be used". This document
deprecates those algorithms that are no longer advised but for which
there are no known attacks resulting in their earlier deprecation.
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.
Wouters Expires August 25, 2021 [Page 2]
Internet-Draft Deprecation of IKEv1 and some algorithms February 2021
3. RFC 2409 to 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.
Such unsupported systems have a much higher chance of containing an
implementation vulnerability that will never be patched. IKEv1
systems can be abused for packet amplification attacks. IKEv1
systems most likely do not support modern algorithms such as AES-GCM
or CHACHA20_POLY1305 and quite often only support or have been
configured to use the very weak Diffie-Hellman Groups 2 and 5. IKEv1
systems should be upgraded or replaced by IKEv2 systems.
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]
Some IKEv1 implementations support Labeled IPsec, a method to
negotiate an addition Security Context selector to the SPD, but this
method was never standarized 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. Deprecating obsolete algorithms
This document deprecates the following algorithms:
o Encryption Algorithms: RC5, IDEA, CAST, Blowfish, and the
unspecified 3IDEA, ENCR_DES_IV64 and ENCR_DES_IV32
o PRF Algorithms: the unspecified PRF_HMAC_TIGER
o Integrity Algorithms: HMAC-MD5-128
o Diffie-Hellman groups: none
5. Security Considerations
There are only security benefits by deprecating IKEv1 for IKEv2.
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.
Wouters Expires August 25, 2021 [Page 3]
Internet-Draft Deprecation of IKEv1 and some algorithms February 2021
6. IANA Considerations
This document instructs IANA to mark all IKEv1 registries as
DEPRECATED.
Additionally, this document 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]
1 PRF_HMAC_TIGER DEPRECATED [this document]
Figure 2
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
Wouters Expires August 25, 2021 [Page 4]
Internet-Draft Deprecation of IKEv1 and some algorithms February 2021
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.
This document instructs IANA to close and mark as obsolete the
Internet Key Exchange (IKE) Attributes registries as well as the
"Magic Numbers" for ISAKMP Protocol registries.
The IESG is requested to designate IKEv1 to Historic.
7. References
7.1. 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>.
[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>.
Wouters Expires August 25, 2021 [Page 5]
Internet-Draft Deprecation of IKEv1 and some algorithms February 2021
[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>.
[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>.
[RFC8223] Esale, S., Torvi, R., Jalil, L., Chunduri, U., and K.
Raza, "Application-Aware Targeted LDP", RFC 8223,
DOI 10.17487/RFC8223, August 2017,
<https://www.rfc-editor.org/info/rfc8223>.
[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>.
[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>.
7.2. Informative References
[draft-ietf-ipsecme-labeled-ipsec]
Wouters, P. and S. Prasad, "Labeled IPsec Traffic Selector
support for IKEv2", draft-ietf-ipsecme-labeled-ipsec (work
in progress), March 2019.
Author's Address
Paul Wouters (editor)
Red Hat
Email: pwouters@redhat.com
Wouters Expires August 25, 2021 [Page 6]
