Network Working Group R. Gieben
Internet-Draft M. Groeneweg
Intended status: Standards Track R. Ribbers
Expires: July 22, 2013 A.L.J. Verschuren
SIDN Labs
January 20, 2013
Key Relay Mapping for the Extensible Provisioning Protocol
draft-gieben-epp-keyrelay-00
Abstract
This document describes an Extensible Provisioning Protocol (EPP)
extension mapping for the purpose of relaying DNSSEC key material
from a one registrar to another. The mapping introduces <keyrelay>
as a new command in EPP.
This command will help facilitating a transfer of a domain while
keeping DNSSEC's 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
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This Internet-Draft will expire on July 22, 2013.
Copyright Notice
Copyright (c) 2013 IETF Trust and the persons identified as the
document authors. All rights reserved.
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Table of Contents
1. Conventions Used in This Document . . . . . . . . . . . . . . 2
2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 2
3. Relaying Key Material . . . . . . . . . . . . . . . . . . . . 3
4. Rational For a New Command . . . . . . . . . . . . . . . . . . 4
5. Key Relay Interface . . . . . . . . . . . . . . . . . . . . . 4
6. Example Key Relay Interface . . . . . . . . . . . . . . . . . 4
7. Server Reply . . . . . . . . . . . . . . . . . . . . . . . . . 5
8. Message Queue Interface . . . . . . . . . . . . . . . . . . . 6
9. Message Queue Format . . . . . . . . . . . . . . . . . . . . . 6
10. Formal Syntax . . . . . . . . . . . . . . . . . . . . . . . . 7
11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9
12. Security Considerations . . . . . . . . . . . . . . . . . . . 9
13. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 10
14. References . . . . . . . . . . . . . . . . . . . . . . . . . . 10
14.1. Normative References . . . . . . . . . . . . . . . . . . 10
14.2. Informative References . . . . . . . . . . . . . . . . . 10
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 10
1. Conventions Used in This Document
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in BCP 14, RFC 2119
[RFC2119].
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.
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
implementation.
The term "key material" denotes one more DNSKEY resource records
[RFC4034].
In Section 1.2 of [I-D.koch-dnsop-dnssec-operator-change] the terms
"losing DNS operator" and "gaining DNS operator" are defined. With
EPP a registry can only talk to its registrars, so in this document
we will use the terms "loosing registrar" and "gaining registrar".
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 or it is non-scalable.
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One of such transactions is changing the DNS operator for DNSSEC
signed zones ([I-D.koch-dnsop-dnssec-operator-change]. 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. Both 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| |gaining registrar|
+-----------------+ +-----------------+
^ |
EPP poll | | EPP keyrelay
| V
+----------------+
| registry |
+----------------+
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 through the registrar it can act as a relay for the key
material exchange.
Figure 1
The "<keyrelay>" command uploads a new key to the registry. This key
material is then relayed to the current registrar's message queue.
There is no need for the registry to store the relayed key in the
registry system, although the registry MAY save the key for
administrative purposes.
The registrar may upload multiple keys in one "<keyrelay>" message.
If keys are identical (Flags Field, Protocol Field, Algorithm Field
and Public Key Field are equal), the duplicate keys MUST be dropped.
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
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to the losing registrar to validate the correctness of the key
material.
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 (discarding any
duplicates) uploaded keys on to the losing registrars' message queue.
4. Rational For a New Command
The keyrelay command is different than the existing EPP commands,
because it allows someone to manipulate data without actually being
to owner of that data. The EPP transfer command comes close with
respect to this functionality. We did not want to overload the
transfer command for this purpose, because a keyrelay has nothing to
do with that operation.
5. Key Relay Interface
The Key Relay Interface uses a "<keyrelay>" element for relay the key
material. It needs a maximum of three elements: a domain name, the
key to upload and optionally a token which indicates a future
transfer is imminent.
The "<keyrelay>" element MUST contain the following child elements:
o A "<ext:name>" element that contains the domain name for which we
upload the key.
o A "<ext:keyData>" element that contains the key material as
described in [RFC5910], Section 4.2.
And MAY contain:
o A "<ext:authInfo>" that contains an authorization token
([RFC5931], Section 3.2.4) This can be used as an extra indication
that the losing and gaining registrar had prior contact and a
possible, future transfer is authorized.
6. Example Key Relay Interface
The following is an example of the "<keyrelay>" command:
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C:<?xml version="1.0" encoding="UTF-8"?>
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>example.org</ext:name>
C: <ext:authInfo>
C: <domain:pw>JnSdBAZSxxzJ</domain:pw>
C: </ext:authInfo>
C: <ext:keyData>
C: <secDNS:flags>256</secDNS:flags>
C: <secDNS:protocol>3</secDNS:protocol>
C: <secDNS:alg>8</secDNS:alg>
C: <secDNS:pubKey>AwEAAc////Vesz</secDNS:pubKey>
C: </ext:keyData>
C: </ext:keyrelay>
C: </ext:command>
C: </extension>
C:</epp>
7. Server Reply
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Example "<keyrelay>" response:
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 succesfully</msg>
S: </result>
S: <trID>
S: <clTRID>ABC-12345</clTRID>
S: <svTRID>54321-ZYX</svTRID>
S: </trID>
S: </response>
S:</epp>
As stated an EPP error response MUST be returned if a "<keyrelay>"
command can not be processed for any reason.
8. Message Queue Interface
9. Message Queue Format
Example "Key Relay" service message:
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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: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>
S: <keyrelay:response>
S: <keyrelay:panData>
S: <keyrelay:name paResult="true">example.org
S: </keyrelay:name>
S: <keyrelay:paTRID>
S: <clTRID>BCD-23456</clTRID>
S: <svTRID>65432-WXY</svTRID>
S: </keyrelay:paTRID>
S: <keyrelay:paDate>1999-04-04T22:01:00.0Z
S: </keyrelay:paDate>
S: <keyrelay:authInfo>
S: <domain:pw>JnSdBAZSxxzJ</domain:pw>
S: </keyrelay:authInfo>
S: <keyrelay:keyData>
S: <secDNS:flags>256</secDNS:flags>
S: <secDNS:protocol>3</secDNS:protocol>
S: <secDNS:alg>8</secDNS:alg>
S: <secDNS:pubKey>AwEAAc////Vesz</secDNS:pubKey>
S: </keyrelay:keyData>
S: </keyrelay:panData>
S: </keyrelay:response>
S: </resData>
S: <trID>
S: <clTRID>BCD-23456</clTRID>
S: <svTRID>65432-WXY</svTRID>
S: </trID>
S: </response>
S:</epp>
10. 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
instances.
"<keyrelay>" command schema:
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<?xml version="1.0" encoding="UTF-8"?>
<schema targetNamespace="urn:ietf:params:xml:ns:keyrelay-1.0"
xmlns:keyrelay="urn:ietf:params:xml:ns:keyrelay-1.0"
xmlns:secDNS="urn:ietf:params:xml:ns:secDNS-1.1"
xmlns:epp="urn:ietf:params:xml:ns:epp-1.0"
xmlns:eppcom="urn:ietf:params:xml:ns:eppcom-1.0"
xmlns:domain="urn:ietf:params:xml:ns:domain-1.0"
xmlns="http://www.w3.org/2001/XMLSchema"
elementFormDefault="qualified">
<annotation>
<documentation>
Extensible Provisioning Protocol v1.0 domain name
extension schema for relaying key material.
</documentation>
</annotation>
<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">
<sequence>
<element name="panData" type="keyrelay:panKeyRelayDataType" />
</sequence>
</complexType>
<complexType name="commandType">
<sequence>
<element name="keyrelay" type="keyrelay:keyRelayType" />
</sequence>
</complexType>
<complexType name="keyRelayType">
<sequence>
<element name="name" type="eppcom:labelType" />
<element name="authInfo" type="domain:authInfoType"
minOccurs="0" />
<element name="keyData" type="secDNS:keyDataType"
minOccurs="1" maxOccurs="unbounded" />
</sequence>
</complexType>
<complexType name="panKeyRelayDataType">
<sequence>
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<element name="name" type="domain:paNameType" />
<element name="paTRID" type="epp:trIDType" />
<element name="paDate" type="dateTime" />
<element name="authInfo" type="domain:authInfoType"
minOccurs="0" />
<element name="keyData" type="secDNS:keyDataType"
minOccurs="1" maxOccurs="unbounded" />
</sequence>
</complexType>
</schema>
11. 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.
12. Security Considerations
The "<keyrelay>" EPP extension does not allow for any object
transformations.
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.
The "<ext:authInfo>" element can be used as an indication that
putting the key material on the losing registar's message queue is
allowed.
Communication between a registrar and registry is mostly done over
EPP, but communication between dns-operators, registrants or
registrars mostly 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 other methods than EPP.
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13. Acknowledgements
Maarten Wullink, Marco Davids and Ed Lewis.
14. References
14.1. 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.
[RFC5910] Gould, J. and S. Hollenbeck, "Domain Name System (DNS)
Security Extensions Mapping for the Extensible
Provisioning Protocol (EPP)", RFC 5910, May 2010.
14.2. Informative References
[I-D.koch-dnsop-dnssec-operator-change]
Koch, P. and M. Sanz, "Changing DNS Operators for DNSSEC
signed Zones", Internet-Draft draft-koch-dnsop-dnssec-
operator-change-04, March 2012.
[RFC5931] Harkins, D. and G. Zorn, "Extensible Authentication
Protocol (EAP) Authentication Using Only a Password", RFC
5931, August 2010.
Authors' Addresses
R. (Miek) Gieben
SIDN Labs
Meander 501
Arnhem 6825 MD
NL
Email: miek@miek.nl
URI: http://miek.nl/
M. Groeneweg
SIDN Labs
Meander 501
Arnhem 6825 MD
NL
Email: marc.groeneweg@sidn.nl
URI: https://www.sidn.nl/
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Rik Ribbers
SIDN Labs
Meander 501
Arnhem 6825 MD
NL
Email: rik.ribbers@sidn.nl
URI: https://www.sidn.nl/
Antoin Verschuren
SIDN Labs
Meander 501
Arnhem 6825 MD
NL
Email: antoin.verschuren@sidn.nl
URI: https://www.sidn.nl/
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