[Docs] [txt|pdf] [Tracker] [Email] [Nits]

Versions: 00

Network Working Group                                        K. Fujiwara
Internet-Draft                                                      JPRS
Intended status: Standards Track                       November 03, 2020
Expires: May 7, 2021


          Delegation Information (Referrals) Signer for DNSSEC
         draft-fujiwara-dnsop-delegation-information-signer-00

Abstract

   DNSSEC does not protect delegation information, it contains NS RRSet
   on the parent side and glue records.  This document defines
   delegation information signer (DiS) resource record for protecting
   the delegation information, by inserting on the parent side of zone
   cut to hold a hash of delegation information.  The DiS resource
   record reuses the type code and wire format of DS resource record,
   and distinguishes it from existing DS RRSet by using a new digest
   type.  This document also describes the usage of DiS resource record
   and shows the implications on security-aware resolvers.  The
   definition and usage are compatible with current DNSSEC.

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 May 7, 2021.

Copyright Notice

   Copyright (c) 2020 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



Fujiwara                   Expires May 7, 2021                  [Page 1]


Internet-Draft               referral-signer               November 2020


   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
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   3
   3.  Specification of the Delegation information Signer  . . . . .   3
     3.1.  New DS RR Usage: Delegation information signer (DiS)  . .   3
     3.2.  DiS resource record in a Zone . . . . . . . . . . . . . .   4
     3.3.  Change of Authoritative servers . . . . . . . . . . . . .   4
     3.4.  Change of validating resolvers  . . . . . . . . . . . . .   4
   4.  Compatibility with the current DNSSEC . . . . . . . . . . . .   4
   5.  Signing Priming Responses . . . . . . . . . . . . . . . . . .   5
   6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   5
   7.  Security Considerations . . . . . . . . . . . . . . . . . . .   5
   8.  Acknowledgments . . . . . . . . . . . . . . . . . . . . . . .   5
   9.  Normative References  . . . . . . . . . . . . . . . . . . . .   5
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . .   6

1.  Introduction

   The current DNSSEC specifications [RFC4033], [RFC4034], [RFC4035] do
   not protect the parent side NS RRSet and glue contained in the
   delegation information.

   Recently, the word "in-domain" is defined by [RFC8499].  The in-
   domain glue is necessary and sufficient glue information for name
   resolution.  [I-D.ietf-dnsop-glue-is-not-optional] proposes that Glue
   records are expected to be returned as part of a referral and if they
   cannot be fitted into the UDP response, TC=1 MUST be set to inform
   the client that the response is incomplete and that TCP SHOULD be
   used to retrieve the full response.

   Then, we can define complete delegation information set that contains
   the parent side NS RRSet and all in-domain glue.  We can generate a
   hash of the parent side NS RRSet and in-domain glue, and put it in
   DNS as a parent side information.

   The delegation information signer (DiS) resource record (RR) is
   inserted at a zone cut (i.e., a delegation point) to hold a hash of
   delegation information (parent side NS RRSet) and required glue.  The
   DiS resource record reuses DS resource record and distinguishes it
   from DS RRSet by using a new digest type and a new algorithm number.




Fujiwara                   Expires May 7, 2021                  [Page 2]


Internet-Draft               referral-signer               November 2020


   Recent DNSSEC validators ignore DS resource records whose algorithm
   and digest type are unknown.  Therefore, DiS resource record does not
   affect current DNSSEC validation.

   DNSSEC validators that support DiS resource record can verify NS
   RRSet and in-domain glue.

   This document defines new DS RR usage, gives examples of how it is
   used and describes the implications on resolvers.  This change is
   compatible with current DNSSEC.

   The meaning and processing the delegation information (parent side NS
   RRSet and glue) are not changed.  The delegation information is used
   for name resolution process, and not used as the result of the name
   resolution.

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
   BCP14 [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

   Many of the specialized terms used in this document are defined in
   DNS Terminology [RFC8499].

3.  Specification of the Delegation information Signer

   This section defines a new usage of the Delegation Signer (DS) RR
   type.

3.1.  New DS RR Usage: Delegation information signer (DiS)

   This document specifies that the new DNSSEC Digest Type XX (it will
   be assigned by IANA) to the Delegation information Signer with
   SHA-256 (DISSHA256) for another DS usage.

   The key tag and algorithm field may require further discussion.

   The digest field is calculated over the parent side NS RRSet
   corresponding to the owner name of the DiS resource record and whole
   in-domain glue for its delegation.

     digest = SHA-256 hash( NS RRSet | in-domain glue RRSets)

   NS RRSet and in-domain glue RRSets are ordered as
   [I-D.ietf-dnsop-dns-zone-digest].



Fujiwara                   Expires May 7, 2021                  [Page 3]


Internet-Draft               referral-signer               November 2020


   Sibling glue and out-of-bailiwick glue are not the data to be signed.

   Wire format and Presentation format are the same as DS Resource
   Record.

3.2.  DiS resource record in a Zone

   The DiS resource record enables delegation information (parent side
   NS RRSet and in-domain glue records) signature validation in a
   validating resolver.

   A DiS RRSet is present at all delegation point even if there is no DS
   RRSet.  Since DiS RRSet has the same type code as DS RRSet except for
   digest type and hash data, details of DiS resource record is the same
   as DS resource record defined in [RFC4035].

   When DNSSEC signer signes a zone, DNSSEC signer

   o  Remove all DiS resource records

   o  for all delegation points, generate new DiS resource record

   o  sign all DS RRSets

3.3.  Change of Authoritative servers

   Authoritative servers need to support
   [I-D.ietf-dnsop-glue-is-not-optional].  Then, referral responses MUST
   contain parent side NS RRSet and whole in-domain glue.

3.4.  Change of validating resolvers

   When a validating resolver receives a referral response with DS RRSet
   and the DS RRSet contains a DS resource record that have DISSHA256
   digest type, the validating resolver SHOULD validate referral NS
   RRSet and in-domain glue.  First, calculate digest from NS RRSet and
   in-domain glue from the referral response.  Compare the digest and
   the digest field from the DiS resource record.  If the digests
   differ, the referral is compromised or modified.  The validating
   resolver can drop the referral.

4.  Compatibility with the current DNSSEC

   Current DNSSEC validators do not know DS resource records with digest
   type DISSHA256 and these DS records should be ignored.  (See
   Section 5.2 of [RFC4035]).





Fujiwara                   Expires May 7, 2021                  [Page 4]


Internet-Draft               referral-signer               November 2020


5.  Signing Priming Responses

   Another use case for DiS resource record is the protection of priming
   responses.

   The priming response is not a referral.  However, it is similar to
   the referral and the priming response is deterministic.

   Then we can put DiS resource record in the root and it can be signed.

   The root DiS resource record contains digest consist of the root NS
   RRSet and all root servers' A and AAAA resource records.

   Currently, TTL value of root servers' A/AAAA differ between root
   servers.  Before considering DiS resource record in root, the TTL
   value of each root server A/AAAA for the root zone and root-
   servers.net zone must match.

6.  IANA Considerations

   IANA is requested to allocate new digest type code for DS resource
   record.

7.  Security Considerations

8.  Acknowledgments

9.  Normative References

   [I-D.ietf-dnsop-dns-zone-digest]
              Wessels, D., Barber, P., Weinberg, M., Kumari, W., and W.
              Hardaker, "Message Digest for DNS Zones", draft-ietf-
              dnsop-dns-zone-digest-14 (work in progress), October 2020.

   [I-D.ietf-dnsop-glue-is-not-optional]
              Andrews, M., "Glue In DNS Referral Responses Is Not
              Optional", draft-ietf-dnsop-glue-is-not-optional-00 (work
              in progress), June 2020.

   [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>.



Fujiwara                   Expires May 7, 2021                  [Page 5]


Internet-Draft               referral-signer               November 2020


   [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>.

   [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>.

   [RFC8499]  Hoffman, P., Sullivan, A., and K. Fujiwara, "DNS
              Terminology", BCP 219, RFC 8499, DOI 10.17487/RFC8499,
              January 2019, <https://www.rfc-editor.org/info/rfc8499>.

Author's Address

   Kazunori Fujiwara
   Japan Registry Services Co., Ltd.
   Chiyoda First Bldg. East 13F, 3-8-1 Nishi-Kanda
   Chiyoda-ku, Tokyo  101-0065
   Japan

   Phone: +81 3 5215 8451
   Email: fujiwara@jprs.co.jp























Fujiwara                   Expires May 7, 2021                  [Page 6]


Html markup produced by rfcmarkup 1.129d, available from https://tools.ietf.org/tools/rfcmarkup/