Internet DRAFT - draft-ietf-dnsop-obsolete-dlv
draft-ietf-dnsop-obsolete-dlv
DNS Operations W. Mekking
Internet-Draft D. Mahoney
Updates: 6698, 6840 (if approved) ISC
Intended status: Standards Track October 31, 2019
Expires: May 3, 2020
Moving DNSSEC Lookaside Validation (DLV) to Historic Status
draft-ietf-dnsop-obsolete-dlv-02
Abstract
This document obsoletes DNSSEC lookaside validation (DLV) and
reclassifies RFCs 4431 and 5074 as Historic. Furthermore, this
document updates RFC 6698 by excluding the DLV resource record from
certificates, and updates RFC 6840 by excluding the DLV registries
from the trust anchor selection.
Status of This Memo
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provisions of BCP 78 and BCP 79.
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This Internet-Draft will expire on May 3, 2020.
Copyright Notice
Copyright (c) 2019 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
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the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 2
3. Discussion . . . . . . . . . . . . . . . . . . . . . . . . . 2
4. Moving DLV to Historic Status . . . . . . . . . . . . . . . . 3
4.1. Documents that reference the DLV RFCs . . . . . . . . . . 3
4.1.1. Documents that reference RFC 4431 . . . . . . . . . . 3
4.1.2. Documents that reference RFC 5074 . . . . . . . . . . 4
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4
6. Security considerations . . . . . . . . . . . . . . . . . . . 4
7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 5
8. Normative References . . . . . . . . . . . . . . . . . . . . 5
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 6
1. Introduction
DNSSEC Lookaside Validation (DLV) was introduced to assist with the
adoption of DNSSEC [RFC4033] [RFC4034] [RFC4035] in a time where the
root zone and many top level domains (TLDs) were unsigned, to help
entities with signed zones under an unsigned parent zone, or that
have registrars that don't accept DS records. The root zone is
signed since July 2010 and as of May 2019, 1389 out of 1531 TLDs have
a secure delegation from the root; thus DLV has served its purpose
and can now retire.
2. Terminology
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
[RFC2119] and [RFC8174].
3. Discussion
One could argue that DLV is still useful because there are still some
unsigned TLDs and entities under those zones will not benefit from
signing their zone. However, keeping the DLV mechanism also has
disadvantages:
o It reduces the pressure to get the parent zone signed.
o It reduces the pressure on registrars to accept DS records.
o It complicates validation code.
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In addition, not every validator actually implemented DLV (only BIND
9 and Unbound) so even if an entity can use DLV to set up an
alternate path to its trust anchor, its effect is limited.
Furthermore, there was one well-known DLV registry (dlv.isc.org) and
that has been deprecated (replaced with a signed empty zone) on
September 30, 2017. With the absence of a well-known DLV registry
service it is unlikely that there is a real benefit for the protocol
on the Internet nowadays.
One other possible reason to keep DLV is to distribute trust anchors
for private enterprises. There are no known uses of DLV for this.
All things considered it is probably not worth the effort of
maintaining the DLV mechanism.
4. Moving DLV to Historic Status
There are two RFCs that specify DLV:
1. RFC 4431 [RFC4431] specifies the DLV resource record.
2. RFC 5074 [RFC5074] specifies the DLV mechanism for publishing
trust anchors outside the DNS delegation chain and how validators
can use them to validate DNSSEC-signed data.
This document moves both RFC 4431 [RFC4431] and RFC 5074 [RFC5074] to
Historic status. This is a clear signal to implementers that the DLV
resource record and the DLV mechanism SHOULD NOT be implemented or
deployed.
4.1. Documents that reference the DLV RFCs
The RFCs that are being moved to Historic status are referenced by a
couple of other documents. The sections below describe what changes
when the DLV RFCs have been reclassified as Historic.
4.1.1. Documents that reference RFC 4431
One RFC makes reference to RFC 4431 [RFC4431].
4.1.1.1. RFC 5074
RFC 5074 [RFC5074], "DNSSEC Lookaside Validation (DLV)" describes the
DLV mechanism itself, and is being moved to Historic status too.
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4.1.2. Documents that reference RFC 5074
Three RFCs make reference to RFC 5074 [RFC5074].
4.1.2.1. RFC 6698
RFC 6698, "The DNS-Based Authentication of Named Entities (DANE)
Transport Layer Security (TLS) Protocol: TLSA" [RFC6698] specifies:
DNSSEC forms certificates (the binding of an identity to a key) by
combining a DNSKEY, DS, or DLV resource record with an associated
RRSIG record. These records then form a signing chain extending from
the client's trust anchors to the RR of interest.
This document updates RFC 6698 to exclude the DLV resource record
from certificates.
4.1.2.2. RFC 6840
RFC 6840, "Clarifications and Implementation Notes for DNS Security
(DNSSEC)" [RFC6840] says that when trust anchors come from different
sources, a validator may choose between them based on the perceived
reliability of those sources. But in reality this does not happen in
validators (both BIND 9 and Unbound have a option for a DLV trust
anchor that can be used solely as a fallback).
This document updates RFC 6840 to exclude the DLV registries from the
trust anchor selection.
4.1.2.3. RFC 8198
RFC 8198, "Aggressive Use of DNSSEC-Validated Cache" [RFC8198] only
references RFC 5074 because aggressive negative caching was first
proposed there.
5. IANA Considerations
IANA should update the annotation of the DLV RR type (code 32769) to
"Obsolete" in the DNS Parameters registry.
6. Security considerations
When the DLV mechanism goes away, zones that rely on DLV for their
validation will be treated as insecure. The chance that this
scenario actually occurs is very low, since no well-known DLV
registry exists.
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7. Acknowledgements
Ondrej Sury for initial review.
8. 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>.
[RFC4033] Arends, R., Austein, R., Larson, M., Massey, D., and S.
Rose, "DNS Security Introduction and Requirements",
RFC 4033, DOI 10.17487/RFC4033, March 2005,
<https://www.rfc-editor.org/info/rfc4033>.
[RFC4034] Arends, R., Austein, R., Larson, M., Massey, D., and S.
Rose, "Resource Records for the DNS Security Extensions",
RFC 4034, DOI 10.17487/RFC4034, March 2005,
<https://www.rfc-editor.org/info/rfc4034>.
[RFC4035] Arends, R., Austein, R., Larson, M., Massey, D., and S.
Rose, "Protocol Modifications for the DNS Security
Extensions", RFC 4035, DOI 10.17487/RFC4035, March 2005,
<https://www.rfc-editor.org/info/rfc4035>.
[RFC4431] Andrews, M. and S. Weiler, "The DNSSEC Lookaside
Validation (DLV) DNS Resource Record", RFC 4431,
DOI 10.17487/RFC4431, February 2006,
<https://www.rfc-editor.org/info/rfc4431>.
[RFC5074] Weiler, S., "DNSSEC Lookaside Validation (DLV)", RFC 5074,
DOI 10.17487/RFC5074, November 2007,
<https://www.rfc-editor.org/info/rfc5074>.
[RFC6698] Hoffman, P. and J. Schlyter, "The DNS-Based Authentication
of Named Entities (DANE) Transport Layer Security (TLS)
Protocol: TLSA", RFC 6698, DOI 10.17487/RFC6698, August
2012, <https://www.rfc-editor.org/info/rfc6698>.
[RFC6840] Weiler, S., Ed. and D. Blacka, Ed., "Clarifications and
Implementation Notes for DNS Security (DNSSEC)", RFC 6840,
DOI 10.17487/RFC6840, February 2013,
<https://www.rfc-editor.org/info/rfc6840>.
[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>.
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[RFC8198] Fujiwara, K., Kato, A., and W. Kumari, "Aggressive Use of
DNSSEC-Validated Cache", RFC 8198, DOI 10.17487/RFC8198,
July 2017, <https://www.rfc-editor.org/info/rfc8198>.
Authors' Addresses
Matthijs Mekking
ISC
Netherlands
Email: matthijs@isc.org
Dan Mahoney
ISC
950 Charter St
Redwood City, CA 94063
USA
Email: dmahoney@isc.org
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