Network Working Group                                          R. Gieben
Internet-Draft                                                    Google
Intended status: Standards Track                            M. Groeneweg
Expires: July 23, 2014                                        R. Ribbers
                                                       A.L.J. Verschuren
                                                               SIDN Labs
                                                        January 19, 2014

       Key Relay Mapping for the Extensible Provisioning Protocol


   This document describes an Extensible Provisioning Protocol (EPP)
   extension mapping for the purpose of relaying DNSSEC key material
   from one DNS operator to another, by using the administrative
   registration channel through the registrant, registrar and registry.
   The mapping introduces "<keyrelay>" as a new command in EPP.

   This command will help facilitate changing the DNS operator of a
   domain while keeping the DNSSEC chain of trust intact.

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

   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 July 23, 2014.

Copyright Notice

   Copyright (c) 2014 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
   ( in effect on the date of

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

Table of Contents

   1.  Conventions Used in This Document . . . . . . . . . . . . . .   2
   2.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
   3.  Relaying Key Material . . . . . . . . . . . . . . . . . . . .   3
   4.  Rational For a New Command  . . . . . . . . . . . . . . . . .   4
   5.  Key Relay Interface . . . . . . . . . . . . . . . . . . . . .   4
     5.1.  Example Key Relay Interface . . . . . . . . . . . . . . .   6
   6.  Server Reply  . . . . . . . . . . . . . . . . . . . . . . . .   6
   7.  Message Queue Interface . . . . . . . . . . . . . . . . . . .   7
     7.1.  Message Queue Format  . . . . . . . . . . . . . . . . . .   7
   8.  Formal Syntax . . . . . . . . . . . . . . . . . . . . . . . .   8
   9.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  10
   10. Security Considerations . . . . . . . . . . . . . . . . . . .  11
   11. Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  11
   12. References  . . . . . . . . . . . . . . . . . . . . . . . . .  11
     12.1.  Normative References . . . . . . . . . . . . . . . . . .  11
     12.2.  Informative References . . . . . . . . . . . . . . . . .  12
   Appendix A.  Changelog  . . . . . . . . . . . . . . . . . . . . .  12
     A.1.  draft-gieben-epp-keyrelay-00  . . . . . . . . . . . . . .  12
     A.2.  draft-gieben-epp-keyrelay-01  . . . . . . . . . . . . . .  12
     A.3.  draft-gieben-epp-keyrelay-02  . . . . . . . . . . . . . .  12
     A.4.  draft-gieben-epp-keyrelay-03  . . . . . . . . . . . . . .  12
     A.5.  draft-eppext-epp-keyrelay-00  . . . . . . . . . . . . . .  13
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  13

1.  Conventions Used in This Document

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   document are to be interpreted as described in BCP 14, RFC 2119

   In examples, "C:" represents lines sent by a protocol client, and
   "S:" represents lines returned by a protocol server.  "////" is used
   to note element values that have been shortened to better fit page
   boundaries.  Indentation and white space in examples is provided only
   to illustrate element relationships and is not a mandatory feature of
   this protocol.

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   XML is case sensitive.  Unless stated otherwise, XML specifications
   and examples provided in this document MUST be interpreted in the
   character case presented in order to develop a conforming

   The term "key material" denotes one or more DNSKEY resource records

2.  Introduction

   Certain transactions for DNSSEC signed zones require an authenticated
   exchange of DNSSEC key material between DNS operators.  Often there
   is no direct secure channel between the two or it is non-scalable.

   One of such transactions is changing the DNS operator for DNSSEC
   signed zones ([I-D.koch-dnsop-dnssec-operator-change].  We suggest
   DNS operators use the administrative channel that is used to
   bootstrap the delegation to relay the key material for the zone.  In
   this document we define a protocol extension for use in EPP that
   helps to implement and automate this transaction.  This protocol
   extension introduces a new command called "<keyrelay>".

3.  Relaying Key Material

   The "<keyrelay>" command uses the existing authenticated EPP channel
   with the registry.  Registrars can securely talk to the registry and
   as such the registry can serve as a drop box for relaying key
   material between them (see Figure 1).

            +-------------------+  DNSKEY  +--------------------+
            |losing DNS operator| <~~~~~~~ |gaining DNS operator|
            +-------------------+          +--------------------+
                             ^              |
                             |              v
              +-----------------+          +---------+
              |current registrar|          |registrar|
              +-----------------+          +---------+
                             ^              |
                    EPP poll |              | EPP keyrelay
                             |              V
                            |    registry    |

    Figure 1: The gaining and losing DNS operators should talk directly
    to each other (the ~ arrow) to exchange the DNSKEY, but often there
    is no trusted path between the two.  As both can securely interact
       with the registry over the administrative channel through the

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      registrar, the registry can act as a relay for the key material

   The "<keyrelay>" command uploads new key(s) to the registry for a
   given domain.  This key material is then relayed to the current
   registrar's message queue.  This may be the same registrar as the one
   that submitted the "<keyrelay>" command in the situation where the
   DNS operators change, but the registrar stays the same.  There is no
   need for the registry to store the relayed key in the registry
   system, although the registry MAY save the "<keyrelay>" message for
   administrative purposes.

   The registrar may upload multiple keys in one "<keyrelay>" message.

   There is no restriction on the type (for instance Key Signing Keys or
   Zone Signing Keys) of keys that can be put in the message.  It is up
   to the gaining DNS operator to select the keys that are needed in the
   losing operator's zone for the intended transaction to complete
   successfully.  It is up to the losing DNS operator to validate the
   correctness of the key material, and remove duplicate keys (Flags
   Field, Protocol Field, Algorithm Field and Public Key Field are
   equal) when identical keys are already in the zone.

   If for some reason the registry can not process the "<keyrelay>"
   command an EPP error response MUST be returned.  If the registry does
   process the "<keyrelay>" command it MUST put all uploaded keys on to
   the current registrar's message queue.

4.  Rational For a New Command

   The existing commands in EPP all deal with data which either has an
   owner, or soon will have one (EPP create).  The "<keyrelay>" command
   is different, because it allows an upload of key material which will
   never have an owner (in the registry system).  All the "<keyrelay>"
   command does is relay data in preparation for one of the other
   existing EPP commands in a process.  This way, existing commands
   don't need to change, and backward compatibility for existing
   commands is guaranteed.  It allows the client to be flexible in
   timing the individual steps necessary to complete a complex process
   like changing the DNS operator for a zone.  Creating a separate
   command also allows the command to be used or extended to relay key
   or other data for other future processes besides DNS operator
   changes.  This new category of EPP commands can best be described as
   "communication command" as it only facilitates communication of data
   between two EPP clients without changing any objects at the registry.

5.  Key Relay Interface

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   The Key Relay Interface uses a "<keyrelay>" element for relaying the
   key material.  It needs a minimum of three elements: a domain name,
   the key(s) to upload, a token which indicates the request is
   authorized by the registrant, and an OPTIONAL expire element.

   Thus a "<keyrelay>" element MUST contain the following child

   o  A "<name>" element that contains the domain name for which we
      upload the key.

   o  A "<keyData>" element that contains the key material as described
      in [RFC5910], Section 4.2.

   o  An "<authInfo>" that contains an authorization token ([RFC5731],
      Section 3.2.4).  This indicates that the registrar has
      authorization from the registrant to change the zone data, and a
      possible future transfer is authorized.  The registry MAY check if
      the "<authInfo>" data is correct and if it does, it MUST return an
      EPP error response if the authorization token is not correct.

   And MAY contain:

   o  An "<expiry>" element that describes the expected lifetime of the
      relayed key(s) in the zone.  The losing DNS operator can use this
      as an indication when to safely remove the inserted key material
      from the zone.  This may be because the transaction that needed
      the insertion is either completed or has been abandoned if not
      completed before this expire time.  The <expiry> element MUST
      contain one of the following child elements:

      *  "<absolute/>": The policy is valid from the current date and
         time until it expires on the specified date and time.

      *  "<relative/>": The policy is valid from the current date and
         time until the end of the specified duration.

      The current date and time are taken from the "<keyrelay>" service
      message's "<qDate>" element, see Section 7.1.

   o  An "<clTRID>" (client transaction identifier) as described in
      [RFC5730], Section 2.5.

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5.1.  Example Key Relay Interface

   The following is an example of the "<keyrelay>" command, where a key
   is uploaded with a relative expire date of one month and 13 days.

   C:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0"
   C:  xmlns:secDNS="urn:ietf:params:xml:ns:secDNS-1.1"
   C:  xmlns:domain="urn:ietf:params:xml:ns:domain-1.0"
   C:  xmlns:ext="urn:ietf:params:xml:ns:keyrelay-1.0">
   C:  <extension>
   C:    <ext:command>
   C:      <ext:keyrelay>
   C:        <ext:name></ext:name>
   C:        <ext:keyData>
   C:           <secDNS:flags>256</secDNS:flags>
   C:           <secDNS:protocol>3</secDNS:protocol>
   C:           <secDNS:alg>8</secDNS:alg>
   C:           <secDNS:pubKey>cmlraXN0aGViZXN0</secDNS:pubKey>
   C:        </ext:keyData>
   C:        <ext:authInfo>
   C:           <domain:pw>JnSdBAZSxxzJ</domain:pw>
   C:        </ext:authInfo>
   C:        <ext:expiry>
   C:           <ext:relative>P1M13D</ext:relative>
   C:        </ext:expiry>
   C:      </ext:keyrelay>
   C:      <ext:clTRID>ABC-12345</ext:clTRID>
   C:    </ext:command>
   C:  </extension>

6.  Server Reply

   Example "<keyrelay>" response:

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   S:<?xml version="1.0" encoding="UTF-8" standalone="no"?>
   S:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
   S:  <response>
   S:    <result code="1000">
   S:       <msg>Command completed successfully</msg>
   S:    </result>
   S:    <trID>
   S:       <clTRID>ABC-12345</clTRID>
   S:       <svTRID>54321-ZYX</svTRID>
   S:    </trID>
   S:  </response>

   As stated an EPP error response MUST be returned if a "<keyrelay>"
   command can not be processed for any reason.

7.  Message Queue Interface

   The message queue interface uses the interface as defined in
   [RFC5730], Section 2.6.  All elements that are present in the
   "<keyrelay>" EPP message are put on the message queue of the current
   registrar for the domain in the "<name>" element.

   A "<keyrelay>" message MUST be delivered to the current registrar's
   message queue, even if the current registrar has indicated that it
   does not support "<keyrelay">.

7.1.  Message Queue Format

   This is an example "<keyrelay>" service message.  Note that the
   optional clTRID in this message is the clTRID value from the command
   that polls the message queue.  It is not the clTRID value used in the
   EPP "<keyrelay>" command.

   S:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0"
   S:  xmlns:secDNS="urn:ietf:params:xml:ns:secDNS-1.1"
   S:  xmlns:domain="urn:ietf:params:xml:ns:domain-1.0"
   S:  xmlns:keyrelay="urn:ietf:params:xml:ns:keyrelay-1.0">
   S:  <response>
   S:     <result code="1301">
   S:        <msg>Command completed successfully; ack to dequeue</msg>
   S:     </result>
   S:     <msgQ count="5" id="12345">
   S:        <qDate>1999-04-04T22:01:00.0Z</qDate>
   S:        <msg>Key Relay action completed successfully.</msg>
   S:     </msgQ>
   S:     <resData>

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   S:        <keyrelay:response>
   S:           <keyrelay:panData>
   S:              <keyrelay:name paResult="true">
   S:              </keyrelay:name>
   S:              <keyrelay:paDate>1999-04-04T22:01:00.0Z
   S:              </keyrelay:paDate>
   S:              <keyrelay:keyData>
   S:                 <secDNS:flags>256</secDNS:flags>
   S:                 <secDNS:protocol>3</secDNS:protocol>
   S:                 <secDNS:alg>8</secDNS:alg>
   S:                 <secDNS:pubKey>cmlraXN0aGViZXN0</secDNS:pubKey>
   S:              </keyrelay:keyData>
   S:              <keyrelay:authInfo>
   S:                 <domain:pw>JnSdBAZSxxzJ</domain:pw>
   S:              </keyrelay:authInfo>
   S:              <keyrelay:expiry>
   S:                 <keyrelay:relative>P24D</keyrelay:relative>
   S:              </keyrelay:expiry>
   S:              <keyrelay:reID>ClientX</keyrelay:reID>
   S:              <keyrelay:acID>ClientY</keyrelay:acID>
   S:           </keyrelay:panData>
   S:        </keyrelay:response>
   S:     </resData>
   S:     <trID>
   S:        <clTRID>BCD-23456</clTRID>
   S:        <svTRID>65432-WXY</svTRID>
   S:     </trID>
   S:  </response>

8.  Formal Syntax

   An EPP object mapping is specified in XML Schema notation.  The
   formal syntax presented here is a complete schema representation of
   the object mapping suitable for automated validation of EPP XML

   "<keyrelay>" command schema:

   <?xml version="1.0" encoding="UTF-8"?>
   <schema targetNamespace="urn:ietf:params:xml:ns:keyrelay-1.0"

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            Extensible Provisioning Protocol v1.0 domain name
            extension schema for relaying key material.

      <import namespace="urn:ietf:params:xml:ns:epp-1.0"
              schemaLocation="epp-1.0.xsd" />
      <import namespace="urn:ietf:params:xml:ns:eppcom-1.0"
              schemaLocation="eppcom-1.0.xsd" />
      <import namespace="urn:ietf:params:xml:ns:secDNS-1.1"
              schemaLocation="secdns-1.1.xsd" />
      <import namespace="urn:ietf:params:xml:ns:domain-1.0"
              schemaLocation="domain-1.0.xsd" />

      <element name="command" type="keyrelay:commandType" />
      <element name="response" type="keyrelay:responseType" />

      <complexType name="responseType">
            <element name="panData"

      <complexType name="commandType">
            <element name="keyrelay"
                     type="keyrelay:keyRelayType" />
            <element name="clTRID" type="epp:trIDStringType"

      <complexType name="keyRelayExpiryType">
            <element name="absolute" type="dateTime" />
            <element name="relative" type="duration" />

      <complexType name="keyRelayType">
            <element name="name" type="eppcom:labelType" />
            <element name="keyData" type="secDNS:keyDataType"

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                     minOccurs="1" maxOccurs="unbounded" />
            <element name="authInfo"
                     type="domain:authInfoType" />
            <element name="expiry"
               type="keyrelay:keyRelayExpiryType" minOccurs="0" />

      <complexType name="panKeyRelayDataType">
            <element name="name" type="domain:paNameType" />
            <element name="paDate" type="dateTime" />
            <element name="keyData" type="secDNS:keyDataType"
                     minOccurs="1" maxOccurs="unbounded" />
            <element name="authInfo" type="domain:authInfoType" />
            <element name="expiry"
               type="keyrelay:keyRelayExpiryType" minOccurs="0" />
            <element name="reID" type="eppcom:clIDType"/>
            <element name="acID" type="eppcom:clIDType"/>

9.  IANA Considerations

   This document uses URNs to describe XML namespaces and XML schemas
   conforming to a registry mechanism described in RFC 3688 [RFC3688].

   Two URI assignments must be completed by the IANA.

   Registration request for the extension namespace:

   URI: urn:ietf:params:xml:ns:keyrelay-1.0

   Registrant Contact: IESG

   XML: None.  Namespace URIs do not represent an XML specification.

   Registration request for the extension XML schema:

   URI: urn:ietf:params:xml:schema:keyrelay-1.0

   Registrant Contact: IESG

   XML: See the "Formal Syntax" section of this document.

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10.  Security Considerations

   The "<keyrelay>" EPP extension does not allow for any object

   Any registrar can use this mechanism to put key material on the
   message queue of another registrar, thus mounting a denial of service
   attack.  However this can, and should be detected by the registry.  A
   correct "<ext:authInfo>" element can be used as an indication that
   putting the key material on the losing registrar's message queue is
   authorized by the registrant of that registrar.  A registry MAY set a
   server policy which limits or rejects "<keyrelay>" messages if it
   detects the mechanism is being abused.

   Communication between a registrar and registry is mostly done over
   EPP, but communication between DNS operators, registrants or
   registrars often is not.  If EPP is not used between these entities,
   relaying the key between a DNS operator and registrar should be
   adequately authenticated for the complete relay channel to remain
   secure.  It's out of scope for this document to describe how to
   authenticate with other methods than EPP.

11.  Acknowledgements

   We like to thank the following individuals for their valuable input,
   review, constructive criticism in earlier revisions or support for
   the concepts described in this document:

   Maarten Wullink, Marco Davids, Ed Lewis, James Mitchell, David Peal,
   Patrik Faltstrom, Klaus Malorny, James Gould, Patrick Mevzek and Seth

12.  References

12.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC3688]  Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
              January 2004.

   [RFC4034]  Arends, R., Austein, R., Larson, M., Massey, D., and S.
              Rose, "Resource Records for the DNS Security Extensions",
              RFC 4034, March 2005.

   [RFC5730]  Hollenbeck, S., "Extensible Provisioning Protocol (EPP)",
              STD 69, RFC 5730, August 2009.

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   [RFC5910]  Gould, J. and S. Hollenbeck, "Domain Name System (DNS)
              Security Extensions Mapping for the Extensible
              Provisioning Protocol (EPP)", RFC 5910, May 2010.

12.2.  Informative References

              Koch, P., Sanz, M., and A. Verschuren, "Changing DNS
              Operators for DNSSEC signed Zones", draft-koch-dnsop-
              dnssec-operator-change-05 (work in progress), July 2013.

   [RFC5731]  Hollenbeck, S., "Extensible Provisioning Protocol (EPP)
              Domain Name Mapping", STD 69, RFC 5731, August 2009.

Appendix A.  Changelog

   [This section should be removed by the RFC editor before publishing]

A.1.  draft-gieben-epp-keyrelay-00

   1.  Initial document.

A.2.  draft-gieben-epp-keyrelay-01

   1.  Style and grammar changes;

   2.  Added an expire element as per suggestion by Klaus Malorny;

   3.  Make the authInfo element mandatory and make the registry check
       it as per feedback by Klaus Malorny and James Gould.

A.3.  draft-gieben-epp-keyrelay-02

   1.  Added element to identify the relaying EPP client as suggested by
       Klaus Malorny;

   2.  Corrected XML for missing and excess clTRID as noted by Patrick

   3.  Added clarifications for the examples based on feedback by
       Patrick Mevzeck;

   4.  Reviewed the consistency of using DNS operator versus registrar
       after review comments by Patrick Faltstrom and Ed Lewis.

A.4.  draft-gieben-epp-keyrelay-03

   1.  Style and grammar changes

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   2.  Corrected acknowledgement section

   3.  Corrected XML for Expire element to not be mandatory but only
       occur once.

A.5.  draft-eppext-epp-keyrelay-00

   1.  Added feedback from Seth Goldman and put him in the
       acknowledgement section.

   2.  IDnits formatting ajustments

Authors' Addresses

   R. (Miek) Gieben


   M. Groeneweg
   SIDN Labs
   Meander 501
   Arnhem  6825 MD


   Rik Ribbers
   SIDN Labs
   Meander 501
   Arnhem  6825 MD


   Antoin Verschuren
   SIDN Labs
   Meander 501
   Arnhem  6825 MD


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