Multiple Algorithm Rules in DNSSEC
draft-huque-dnsop-multi-alg-rules-02

Internet Engineering Task Force                                 S. Huque
Internet-Draft                                                Salesforce
Updates: 4035, 6840, 8624 (if approved)                     P. Thomassen
Intended status: Standards Track                              deSEC, SSE
Expires: 10 May 2024                                         V. Dukhovni
                                                              Google LLC
                                                              D. Wessels
                                                                Verisign
                                                         7 November 2023

                   Multiple Algorithm Rules in DNSSEC
                  draft-huque-dnsop-multi-alg-rules-02

Abstract

   This document restates the requirements on DNSSEC signing and
   validation and makes small adjustments in order to allow for more
   flexible handling of configurations that advertise multiple Secure
   Entry Points (SEP) with different signing algorithms via their DS
   record or trust anchor set.  The adjusted rules allow both for multi-
   signer operation and for the transfer of signed DNS zones between
   providers, where the providers support disjoint DNSSEC algorithm
   sets.  In addition, the proposal enables pre-publication of a trust
   anchor in preparation for an algorithm rollover, such as of the root
   zone.

   This document updates RFCs 4035, 6840, and 8624.

Discussion Venues

   This note is to be removed before publishing as an RFC.

   Source for this draft and an issue tracker can be found at
   https://github.com/shuque/draft-dnsop-multi-alg-rules.

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/.

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Table of Contents

   1.  Introduction and Motivation . . . . . . . . . . . . . . . . .   3
   2.  Proposed Updates to RFCs  . . . . . . . . . . . . . . . . . .   4
     2.1.  Minimal Approach  . . . . . . . . . . . . . . . . . . . .   4
     2.2.  Comprehensive Approach  . . . . . . . . . . . . . . . . .   5
       2.2.1.  Updates to RFC 8624 . . . . . . . . . . . . . . . . .   5
       2.2.2.  Signer Requirements . . . . . . . . . . . . . . . . .   6
       2.2.3.  Validator Requirements  . . . . . . . . . . . . . . .   6
       2.2.4.  Discussion  . . . . . . . . . . . . . . . . . . . . .   7
   3.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   7
   4.  Security Considerations . . . . . . . . . . . . . . . . . . .   8
     4.1.  Minimal approach  . . . . . . . . . . . . . . . . . . . .   8
     4.2.  Comprehensive approach  . . . . . . . . . . . . . . . . .   8
       4.2.1.  Time Dependency of UNIVERSAL Algorithms . . . . . . .   9
     4.3.  Variable Key Size Algorithms  . . . . . . . . . . . . . .  10
   5.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  10
   6.  Normative References  . . . . . . . . . . . . . . . . . . . .  10
   7.  Informative References  . . . . . . . . . . . . . . . . . . .  11
   Appendix A.  Current Multiple Algorithm Rules . . . . . . . . . .  11
     A.1.  Signing Requirements  . . . . . . . . . . . . . . . . . .  11
     A.2.  Validator Requirements  . . . . . . . . . . . . . . . . .  12
     A.3.  Incompatible Use Cases  . . . . . . . . . . . . . . . . .  12
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  13

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1.  Introduction and Motivation

   The Domain Name System Security Extensions (DNSSEC) [RFC4033]
   [RFC4034] [RFC4035] add data origin authentication and integrity
   protection to the Domain Name System (DNS), by having DNS zone owners
   (or their operators) crytographically sign their zone data.

   Current specifications [RFC4035][RFC6840] require that a zone be
   signed with each signing algorithm listed in a zone's DS RRset or
   appearing via its trust anchors (TAs).  This poses a problem for (at
   least) the following cases:

   *  In multi-signer setups (Multi-Signer Extensions [RFC8901]
      Section 2.1.2), multiple providers using distinct DNSSEC keys can
      cooperatively serve the same DNS zone.  This methods does not work
      however if the providers involved employ different DNSSEC
      algorithms.

   *  DNSSEC Automation [DNSSEC-AUTO] further describes how to fully
      automate Multi-Signer operations, including how to use a
      transitional state of a multi-signer configuration to non-
      disruptively transfer a signed zone from one provider to another.
      If the old and the new provider do not use the same signing
      algorithms, the same problem is encountered.

   *  When performing an algorithm rollover for a zone with a trust
      anchor, current specifications mandate that the zone has to be
      double-signed with both the old and the new algorithm before
      publishing the new trust anchor.  For the root zone, this could
      lead to a potentially rather long phase of double-signing (on the
      order of a year).  As this comes with both financial and
      operational risks, it seems desirable to find a way for publishing
      the new trust anchor without introducing the new algorithm into
      the zone just yet.

   *  Furthermore, for online signers, producing on the fly signatures
      for several algorithms imposes a significant computational burden.

   The above issues are not just a theoretical problem.  Real situations
   in the field have occurred where the existing requirements have posed
   an obstacle to DNSSEC deployment and operations.

   That said, the existing signing requirements are well motivated: When
   a zone's DS RRset or trust anchor set includes multiple DNSKEY
   algorithms, an attacker who can strip all the supported RRSIGs from a
   signed response from that zone, leaving just the unsupported
   signatures, must not be able to disable validation for that zone,
   effectively downgrading the zone to "insecure".  The rules therefore

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   ensure the downgrade resistance of DNSSEC when only some, but not
   all, of a zone's DS RRset or trust anchor set DNSKEY algorithms are
   supported by a validating resolver.

   This document proposes modifications of the signing and validation
   rules to accommodate additional use cases, without compromising the
   security guarantees given by DNSSEC.

2.  Proposed Updates to RFCs

   The heart of the issue is that even though any one acceptable
   signature suffices for validation, the signer cannot, in the general
   case, know which particular signing algorithm(s) the validator will
   support; and hence, providing a "large enough set" (read: all of
   them) is the approach that had been taken so far.

   This is set down in Section 2.2 of [RFC4035]:

   |  There MUST be an RRSIG for each RRset using at least one DNSKEY of
   |  each algorithm in the zone apex DNSKEY RRset.  The apex DNSKEY
   |  RRset itself MUST be signed by each algorithm appearing in the DS
   |  RRset located at the delegating parent (if any).

   In the following, two different ways of amending this existing
   specification are described.  Both methods advocate that signers
   adopt a more liberal approach to the requirement of signatures by
   algorithm sets.  The minimal approach provides cautionary advice to
   zone owners about the selection of appropriate algorithm sets.  The
   comprehensive approach more precisely defines which algorithms are
   safe to use in this way, and additionally places some of the burden
   on validating resolvers to ensure this safety.

2.1.  Minimal Approach

   The most straightforward proposal is to relax the rule quoted from
   RFC 4035 by changing the MUST to a SHOULD, and state that there are
   valid configurations where this rule could be disregarded.

   This approach puts the burden on the zone owners/ signers to only
   select suitably strong and well supported algorithms (such as
   algorithms 8 and 13).  It does not require any new changes to
   validating resolvers - they just have to follow the clarifying rule
   in RFC 6840 that any valid authentication path is acceptable.  It
   thus represents a minimal approach to achieving the goals outlined in
   the abstract.

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   If zone owners do not carefully select such a set of widely supported
   algorithms, this can cause problems.  For example, if they choose 7
   as one of the algorithms, it may cause validators to return SERVFAIL
   under certain circumstances.

   More explicitly, a zone that is using such an algorithm as its sole
   signing algorithm is (correctly) treated as insecure by resolvers
   that do not support that algorithm.  When attempting to transfer the
   domain to another DNS provider through a multi-signer setup with a
   supported algorithm, affected resolvers will return SERVFAIL when
   presented with the unsupported signature only.  Zone owners and
   signers thus must take great care to not leave a validating resolver
   without a valid supported path when transitioning e.g. from algorithm
   7 to 13.

2.2.  Comprehensive Approach

   This approach establishes a mechanism allowing the signer to
   determine which RRSIGs can be skipped, without risking validation
   failures.  It does not require all algorithms' RRSIGs to be present,
   while ensuring that the set of signatures provided is still "large
   enough" for reliable DNSSEC operation, so that robust multi-signer
   operation and TA pre-publication are made possible, without risking
   validation failures.

   For the case of a multi-signer setup with two generally supported
   algorithms (such as 8 and 13), the scheme requires only one of the
   two signatures.  Similarly, when pre-publishing a trust anchor,
   associated signatures don't need to be published immediately,
   provided that the existing TA's algorithm is generally supported.

2.2.1.  Updates to RFC 8624

   The notion of UNIVERSAL signing algorithms is introduced, and defined
   as follows:

   *  The information contained in the table of [RFC8624] Section 3.1 is
      transferred into a to-be-erected IANA registry, and a boolean
      column is added with the heading "universal validation support".
      Signing algorithms where this column is TRUE are called
      "UNIVERSAL".

   *  "MUST validate" is a prerequisite for UNIVERSAL.  Changes that
      affect whether an algorithm is UNIVERSAL require standards action.

   *  Algorithms 8 and 13 are the only algorithms initially declared
      UNIVERSAL.

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   Also, the notion of FORMERLY UNIVERSAL signing algorithms is
   introduced:

   *  As soon as a UNIVERSAL algorithm is known or expected to have
      declining validation support, it should be moved to FORMERLY
      UNIVERSAL.

   *  Algorithms 5 and 7 are the only algorithms initially declared
      FORMERLY UNIVERSAL.  [ TODO Were 1, 3, 6, 12 ever universally
      supported? ]

2.2.2.  Signer Requirements

   1.  Absent any UNIVERSAL algorithms in the DS RRset or trust anchor
       set, or when any FORMERLY UNIVERSAL algorithms are present,
       signers MUST sign with all algorithms listed.

   2.  Otherwise, signers MUST sign with at least one UNIVERSAL
       algorithm listed in the DS RRset or trust anchor set.  Other
       signatures are OPTIONAL.

   UNIVERSAL and FORMERLY UNIVERSAL algorithms SHOULD NOT appear
   together in a DS RRset or trust anchor set.  In fact, FORMERLY
   UNIVERSAL algorithms are best avoided: signers SHOULD transition to
   other algorithms that are UNIVERSAL.

2.2.3.  Validator Requirements

   1.  When the DS RRset or trust anchor set for a zone includes an
       unsupported FORMERLY UNIVERSAL algorithm, validators MUST treat
       the zone as unsigned, even if the DS RRset or trust anchor set
       lists another supported algorithm.

   2.  Otherwise, validators MUST accept any valid path.

   Implementing these rules requires validators to keep a record of
   unsupported FORMERLY UNIVERSAL algorithms, so that the zone's
   security status can be established upon inspection of a DS record or
   TA set.

   Any UNIVERSAL algorithms that a validator supports by default but are
   disabled on the validator as a matter of local policy SHOULD also be
   considered FORMERLY UNIVERSAL unless explicitly configured as
   "unsupported".  The choice should be made with care.  Disabling an
   algorithm to FORMERLY UNIVERSAL downgrades zones signed with the
   disabled algorithm, while disabling it as "unsupported" risks making
   some zones "bogus", if it was used as the only signing algorithm by
   one of the signers in a multi-signer, multi-algorithm setup.

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2.2.4.  Discussion

   It is observed that validators need only to know the concept of
   "FORMERLY UNIVERSAL"; knowledge of which algorithms are UNIVERSAL is
   not required.  This limits the implementation effort.

   The new validation requirements enable stable multi-signer setups
   using UNIVERSAL algorithms as well as robust provider transfers and
   algorithm upgrades from FORMERLY UNIVERSAL to UNIVERSAL algorithms
   (such as algorithm 7 to 13), without risking SERVFAIL responses in
   the event that a validator no longer supports one of the algorithms
   (e.g. 7).  For a detailed discussion, see Security Considerations
   (Section 4.2).

   DNS operators in a multi-signer setup are free to limit their
   responses to serve signatures for one UNIVERSAL algorithm only.  This
   one signature is sufficient to provide a valid path everywhere.

   When a UNIVERSAL algorithm is in use, signatures of other algorithms
   are not required.  DNS providers are thus free to introduce
   additional algorithms (which were never UNIVERSAL) without forcing
   other participating providers to do the same.

   When trust anchors are in use for a zone and there is one with a
   UNIVERSAL algorithm, it is permissible to introduce a new trust
   anchor for a different algorithm before introducing the corresponding
   DNSKEY and RRSIGs into the zone.  (Of course, they need to be added
   before the old trust anchor is removed.)

   If the added trust anchor is also for a UNIVERSAL algorithm, it is
   permissible to eventually switch to returning just the RRSIGs for the
   new algorithm, without an intermediate dual-signing period.  If the
   new trust anchor is not yet UNIVERSAL, a dual signing period is
   required in order to complete the algorithm rollover.

   In typical cases, particularly in the case of the root zone, both
   algorithms will be UNIVERSAL.  In a hypothetical emergency situation
   where only the new algorithm is UNIVERSAL and the old was just
   downgraded to FORMERLY UNIVERSAL, the new signatures would need to be
   introduced immediately.  A short dual signing period would then be
   required for continuity.  Validators would be expected to defer
   disabling the old algorithm until after the root zone rollover is
   completed.

3.  IANA Considerations

   The minimal approach (Section 2.1) has no IANA actions.

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   When the comprehensive approach (Section 2.2) is taken, this section
   will need to be updated to describe the construction of the new IANA
   registry for the implementation status and requirements of DNSSEC
   signing algorithms.

4.  Security Considerations

4.1.  Minimal approach

   The minimal approach requires the zone owner and signer(s) to take
   great care in order to not break working setups by entering a multi-
   signer setup.  In particular, when transferring a zone to another DNS
   provider and switching from e.g. algorithm 7 to 13 in the process,
   resolvers that do no longer support algorithm 7 will expect a valid
   path for algorithm 13.  If the response only contains an RRSIG for
   algorithm 7, the result will be SERVFAIL.

   The minimal approach is thus only workable in cases where the multi-
   signer setup involves universally supported algorithms exclusively.
   As the set of universally supported algorithms evolves over time,
   zone owners and signers need to monitor developments and upgrade
   algorithms before validation support for the involved algorithms is
   declining and SERVFAIL looms.

4.2.  Comprehensive approach

   The new validation requirements presume that zones using multiple
   algorithms are either in a state of transition (e.g. when switching
   providers) or in a permanent multi-provider configuration.  In the
   first case, if the outgoing algorithm is not supported by the
   validator, the zone would have been treated as insecure before the
   transition.  For the second case, it is noted that the purpose of
   multi-provider setups is to provide resilience against any single
   provider's failure.  Consequently, the zone owner is assumed to
   consider the security guarantees given by any single provider to be
   acceptable for the whole zone.  By implication, if one of the
   providers has fallen behind and is signing with an algorithm that is
   no longer supported by some resolvers (and thus promises no
   security), there is no guarantee of DNSSEC security for the zone.

   In other words, the validation requirements guarantee that a zone in
   a multi-provider setup has the same security level as if all but one
   of the involved providers would be unavailable.  Consequently, when
   the configuration involves an algorithm that is no longer universally
   supported, non-supporting validators may treat the zone as insecure.
   This resolves undue SERVFAIL issues that could occur with certain
   algorithm combinations under the previous rules.

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   For example, a zone using only algorithm 7 is treated as insecure by
   validators that do not support this algorithm.  (This is as before.)
   When transferring the domain to another provider via a multi-signer
   setup with algorithm 13, however, the zone's security status will now
   remain "insecure", as the DS RRset still includes FORMERLY UNIVERSAL
   algorithm 7.  The presence of algorithm 13 is inconsequential at this
   point.  Only once algorithm 7 is removed, the zone turns secure.

   This rule acknowledges the fact that the signer is using a FORMERLY
   UNIVERSAL algorithm that SHOULD NOT be used for signing, which might
   render the zone insecure for validators that lack support.  This
   prevents validation breakage when the validator encounters an
   unsupported RRSIG from an outdated algorithm, and allows for glitch-
   free algorithm upgrades with the security status of the zone changing
   only once the transition is complete.

   Validators supporting both algorithms retain security throughtout the
   transition.  In case of a permanent multi-signer setup, the zone
   maintainer needs to move from the FORMERLY UNIVERSAL algorithm to a
   UNIVERSAL one in order to restore universal validation.

4.2.1.  Time Dependency of UNIVERSAL Algorithms

   The same situation occurs when an algorithm is removed from the set
   of UNIVERSAL algorithms.  In this case, the algorithm will become
   FORMERLY UNIVERSAL.  If the zone continues to use the FORMERLY
   UNIVERSAL algorithm, it will continue to be accepted by supporting
   validators, while non-supporting validators will treat the zone as
   insecure until the algorithm is replaced.

   Conversely, when an algorithm is added to the set of UNIVERSAL ones,
   signers MAY begin to return signatures for just that algorithm.  This
   is, in fact, not a problem, as validators do not need to know the
   concept of UNIVERSAL; they just need to support that algorithm (or,
   typically, explicitly classify it as FORMERLY UNIVERSAL).  A problem
   could only occur if the corresponding RRSIG was not supported by a
   non-negligible population of validators; however, in that case
   labeling the algorithm as UNIVERSAL would have been premature.
   Determining universal support cannot be solved on the protocol level,
   and it is the community's responsibility to only advance an algorithm
   to UNIVERSAL when safe enough, i.e. when the population of validators
   lacking support is deemed negligible.

   Validators dropping support for FORMERLY UNIVERSAL algorithms (e.g.
   7) without implementing this specification will produce SERVFAIL
   responses for multi-signer setups involving the disabled algorithm.
   Implementation of the new validation rules is thus advised as soon as
   support for an algorithm is dropped.

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4.3.  Variable Key Size Algorithms

   Since algorithm 8 supports variable key sizes, multi-signer
   configurations involving 8 and 13 should take care to employ an RSA
   keylength that is computationally infeasible to attack.

5.  Acknowledgements

   The minimal proposal in this draft was originally proposed in
   [ICANN-TALK] by Shumon Huque at the ICANN73 DNSSEC and Security
   workshop.

   The comprehensive approach was originally proposed by Peter Thomassen
   and Viktor Dukhovni after discussions on the problem space with
   Edward Lewis, Jakob Schlyter, Johan Stenstam, Shumon Huque, Steve
   Crocker, and Duane Wessels.

6.  Normative References

   [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>.

   [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>.

   [RFC8624]  Wouters, P. and O. Sury, "Algorithm Implementation
              Requirements and Usage Guidance for DNSSEC", RFC 8624,
              DOI 10.17487/RFC8624, June 2019,
              <https://www.rfc-editor.org/info/rfc8624>.

   [RFC8901]  Huque, S., Aras, P., Dickinson, J., Vcelak, J., and D.
              Blacka, "Multi-Signer DNSSEC Models", RFC 8901,
              DOI 10.17487/RFC8901, September 2020,
              <https://www.rfc-editor.org/info/rfc8901>.

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7.  Informative References

   [DNSSEC-AUTO]
              Wisser, U. and S. Huque, "DNSSEC Automation",
              <https://www.ietf.org/archive/id/draft-ietf-dnsop-dnssec-
              automation-01.html>.

   [ICANN-TALK]
              Huque, S., "RFC Adjustments for Multi-Signer",
              <https://tinyurl.com/multisigner-rfc-adjustments>.

Appendix A.  Current Multiple Algorithm Rules

   This section discusses the multi-algorithm requirements on signers
   and validators, as specified by the original DNSSEC specification and
   in effect until updated by this document.  It is included for purely
   informational purposes and context.

A.1.  Signing Requirements

   In addition to the last paragraph of [RFC4035] Section 2.2 quoted
   earlier, Section 5.11 of [RFC6840] clarifies:

   |  A signed zone MUST include a DNSKEY for each algorithm present in
   |  the zone's DS RRset and expected trust anchors for the zone.

   While it might seem tempting, relaxing this rule without any further
   adjustments may not be safe depending on the algorithm combination
   involved.  In particular, when using an algorithm that is not
   universally supported among the resolver population (such as
   algorithm 7) together with a supported one (such as algorithm 13),
   resolvers may return SERVFAIL under certain circumstances.  Zone
   owners and signers thus would have to take great care to not leave a
   validating resolver without a valid supported path in such
   situations, e.g. when transitioning from algorithm 7 to 13.

   More explicitly, when the sole signing algorithm used by a zone is
   not supported by a given resolver, the resolver will (correctly)
   treat that zone as unsigned.  However, when attempting to transfer
   the domain to another DNS provider through a multi-signer setup with
   a supported algorithm, affected resolvers presented with the
   unsupported signature only will not be able to distinguish this
   situation from a downgrade-to-insecure attack where the second
   signature has been stripped, and will return SERVFAIL.

   Although unstated in that document, the above rule prevents this kind
   of downgrade-to-insecure attack by requiring RRSIGs for all
   advertised algorithms; a validator can thus assume that something is

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   wrong when supported signatures are missing.  As a side effect, the
   rule also protects against downgrade-to-weaker attacks, where an
   attacker would strip away signatures from signed DNS responses and
   only attach one for an algorithm that the attacker is able to forge.
   This property is not a core guarantee of DNSSEC (see below).

A.2.  Validator Requirements

   In general, when a validating resolver supporting any of the
   algorithms listed in a given zone's DS record or TA set responds to a
   query without the CD flag set, it may not treat that zone as
   insecure, but must return either validated data (AD=1) or RCODE=2
   (SERVFAIL).  For this purpose, any valid path suffices; the validator
   may not apply a "logical AND" approach to all advertised algorithms.

   Accordingly, Section 5.11 of DNSSEC Clarifications [RFC6840] states:

   |  This requirement applies to servers, not validators.  Validators
   |  SHOULD accept any single valid path.  They SHOULD NOT insist that
   |  all algorithms signaled in the DS RRset work, and they MUST NOT
   |  insist that all algorithms signaled in the DNSKEY RRset work.

   At first glance, the assertions that (1) the signer provide
   signatures for all advertised algorithms while (2) the resolver shall
   be content with just one seems somewhat contradictory.  However, the
   role of the RRSIG rules is to ensure that the resolver will find a
   valid path (using a "logical OR" strategy), regardless of which
   particular algorithm(s) it supports, and thus be able to distinguish
   reliably between "all is in order" (validated data) and a downgrade-
   to-insecure attack (SERVFAIL).

A.3.  Incompatible Use Cases

   The above rules are incompatible with certain use cases:

   *  They are impractical to satisfy if DNS providers deployed in a
      multi-signer configuration are using different signing algorithms.
      By extension, it also means that multi-signer techniques cannot be
      employed to non-disruptively transfer a signed zone from one DNS
      provider to another if the providers use differing algorithms.

   *  The rules further collide with the conflicting goal of pre-
      publishing the new trust anchor during a zone's algorithm
      rollover, while introducing the new algorithm into the zone only
      later in the process.

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   *  Furthermore, for online signers attempting to deploy multiple
      algorithms, producing signatures for several algorithms also
      imposes a significant computational burden, unless a selective
      algorithm negotiation mechanism is also developed.

   As the above rules present a severe limitation for these use cases,
   this document proposes to relax them in a way so that the set of
   signatures provided is still "large enough" to ensure reliable DNSSEC
   operation, while facilitating the above use cases.

Authors' Addresses

   Shumon Huque
   Salesforce
   Email: shuque@gmail.com

   Peter Thomassen
   deSEC, SSE
   Email: peter@desec.io

   Viktor Dukhovni
   Google LLC
   Email: ietf-dane@dukhovni.org

   Duane Wessels
   Verisign
   Email: dwessels@verisign.com

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