Extensible Provisioning Protocol (EPP) mapping for DELEG records

Introduction The Internet-Draft "Extensible Delegation for DNS" () aims to provide an enhanced method of delegation in the DNS, as an alternative to the traditional NS record. This document describes an extension to the EPP domain mapping () to allow EPP clients to provision DELEG records for domain names in an EPP server. EPP provides mechanisms for extending the protocol by (a) adding new properties to existing object mappings and (b) definining new object mappings. Although EPP supports two different models for traditional NS records (host attributes and host objects, as described in ), this document only uses the former, and does not define a new object mapping for DELEG records because the DELEG specification itself implements many of the features that would otherwise require an object mapping: for example the "AliasMode" mode, which allows the delegation information for many domains to be managed as a single set.

Conventions used in this document 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 BCP 14 when, and only when, they appear in all capitals, as shown here. In examples, "C:" represents lines sent by a protocol client and "S:" represents lines returned by a protocol server. Indentation and white space in examples are provided only to illustrate element relationships and are not required features of this protocol. A protocol client that is authorized to manage an existing object is described as a "sponsoring" client throughout this document. 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. EPP uses XML namespaces to provide an extensible object management framework and to identify schemas required for XML instance parsing and validation. These namespaces and schema definitions are used to identify both the base protocol schema and the schemas for managed objects. The XML namespace prefixes used in examples (such as the string deleg in deleg:create) are solely for illustrative purposes. A conforming implementation MUST NOT require the use of these or any other specific namespace prefixes.

Extension elements This document defines a new element, <deleg:deleg>, which appears in query and transform commands for domain objects. This element is a representation of a DELEG record in XML. Note that DELEG records have the same presentation format as SVCB records (). The <deleg:deleg> element has the following attributes:

a priority attribute, which is an integer that corresponds to the SvcPriority field;
a target attribute, which corresponds to the TargetName field.

The <deleg:deleg> element MAY have a single child element, <deleg:params>, which corresponds to the svcParams field. DELEG record SvcParams are mapped onto this element's attributes, with SvcParamKey being the attribute name, and SvcParamValue being its value.

Examples Example "AliasMode" <deleg:deleg> element: ]]> Example "ServiceMode" <deleg:deleg> element: ]]>

EPP command mapping

EPP query commands

EPP <info> command This extension defines an additional element for EPP <info> responses for domain object. When a server receives a domain or host <info> command from a client which included the extension namespace in the <svcExtension> element of the <login> command, the response MUST contain an <extension> element, which MUST contain a <deleg:infData> element. This element MAY contain one or more <deleg:deleg> elements as described in . Example <info> 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 successfully</msg> S: </result> S: <resData> S: <domain:infData S: xmlns:domain="urn:ietf:params:xml:ns:domain-1.0"> S: <domain:name>example.com</domain:name> S: <domain:roid>EXAMPLE1-REP</domain:roid> S: <domain:status s="ok"/> S: <domain:clID>ClientX</domain:clID> S: <domain:crID>ClientX</domain:crID> S: <domain:crDate>2023-11-08T10:14:55.0Z</domain:crDate> S: <domain:exDate>2024-11-08T10:14:55.0Z</domain:exDate> S: </domain:infData> S: </resData> S: <extension> S: <deleg:infData S: xmlns:deleg="urn:ietf:params:xml:ns:epp:deleg-0.01"> S: <deleg:deleg priority="1" target="ns1.example.com"> S: <deleg:params S: ipv4hint="192.0.2.1" S: ipv6hint="2001:DB8::1"/> S: </deleg:deleg> S: <deleg:deleg priority="1" target="ns2.example.net"> S: <deleg:params S: ipv4hint="192.0.2.2" S: ipv6hint="2001:DB8::2"/> S: </deleg:deleg> S: </deleg:infData> S: </extension> S: <trID> S: <clTRID>ABC-12345</clTRID> S: <svTRID>54322-XYZ</svTRID> S: </trID> S: </response> S:</epp>

EPP transform commands

EPP <create> command This extension defines an additional element for EPP <create> commands for domain objects. The <command> element of the <create> command frame MAY contain an <extension> element which MAY contain a <deleg:create> element. This element MUST contain one or more <deleg:deleg> records as described in . Example <create> command: C:<?xml version="1.0" encoding="UTF-8" standalone="no"?> C:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0"> C: <command> C: <create> C: <domain:create C: xmlns:domain="urn:ietf:params:xml:ns:domain-1.0"> C: <domain:name>example.com</domain:name> C: <domain:period unit="y">1</domain:period> C: <domain:authInfo> C: <domain:pw/> C: </domain:authInfo> C: </domain:create> C: </create> C: <extension> C: <deleg:create C: xmlns:deleg="urn:ietf:params:xml:ns:epp:deleg-0.01"> C: <deleg:deleg priority="1" target="ns1.example.com"> C: <deleg:params C: ipv4hint="192.0.2.1" C: ipv6hint="2001:DB8::1"/> C: </deleg:deleg> C: <deleg:deleg priority="1" target="ns2.example.net"> C: <deleg:params C: ipv4hint="192.0.2.2" C: ipv6hint="2001:DB8::2"/> C: </deleg:deleg> C: </deleg:create> C: </extension> C: <clTRID>ABC-12345</clTRID> C: </command> C:</epp>

EPP <update> command This extension defines an additional element for EPP <update> commands for domain objects. The <command> element of the <create> command frame MAY contain an <extension> element which MAY contain a <deleg:update> element. The <deleg:update> element has the following child elements:

An OPTIONAL <deleg:add> element, containing any <deleg:deleg> records to be added to the domain; and
An OPTIONAL <deleg:rem> element, containing any <deleg:deleg> records to be removed from the domain.

Example <update> command, which removes one <deleg:deleg> record and adds another: C:<?xml version="1.0" encoding="UTF-8" standalone="no"?> C:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0"> C: <command> C: <update> C: <domain:update C: xmlns:domain="urn:ietf:params:xml:ns:domain-1.0"> C: <domain:name>example.com</domain:name> C: </domain:update> C: </update> C: <extension> C: <deleg:update xmlns:deleg="urn:ietf:params:xml:ns:epp:deleg-0.01"> C: <deleg:add> C: <deleg:deleg priority="1" target="ns3.example.org"> C: <deleg:params C: ipv4hint="192.0.2.3" C: ipv6hint="2001:DB8::3"/> C: </deleg:deleg> C: </deleg:add> C: <deleg:rem> C: <deleg:deleg priority="1" target="ns1.example.com"> C: <deleg:params C: ipv4hint="192.0.2.1" C: ipv6hint="2001:DB8::1"/> C: </deleg:deleg> C: </deleg:rem> C: </deleg:update> C: </extension> C: <clTRID>ABC-12345</clTRID> C: </command> C:</epp> Example <update> command, which removes one <deleg:deleg> record but does not add any: C:<?xml version="1.0" encoding="UTF-8" standalone="no"?> C:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0"> C: <command> C: <update> C: <domain:update C: xmlns:domain="urn:ietf:params:xml:ns:domain-1.0"> C: <domain:name>example.com</domain:name> C: </domain:update> C: </update> C: <extension> C: <deleg:update xmlns:deleg="urn:ietf:params:xml:ns:epp:deleg-0.01"> C: <deleg:rem> C: <deleg:deleg priority="1" target="ns3.example.org"> C: <deleg:params C: ipv4hint="192.0.2.3" C: ipv6hint="2001:DB8::3"/> C: </deleg:deleg> C: </deleg:rem> C: </deleg:update> C: </extension> C: <clTRID>ABC-12345</clTRID> C: </command> C:</epp> Example <update> command, which adds one <deleg:deleg> record but does not remove any: C:<?xml version="1.0" encoding="UTF-8" standalone="no"?> C:<epp xmlns="urn:ietf:params:xml:ns:epp-1.0"> C: <command> C: <update> C: <domain:update C: xmlns:domain="urn:ietf:params:xml:ns:domain-1.0"> C: <domain:name>example.com</domain:name> C: </domain:update> C: </update> C: <extension> C: <deleg:update xmlns:deleg="urn:ietf:params:xml:ns:epp:deleg-0.01"> C: <deleg:add> C: <deleg:deleg priority="1" target="ns3.example.org"> C: <deleg:params C: ipv4hint="192.0.2.3" C: ipv6hint="2001:DB8::3"/> C: </deleg:deleg> C: </deleg:add> C: </deleg:update> C: </extension> C: <clTRID>ABC-12345</clTRID> C: </command> C:</epp>

Relationship between DELEG and host objects/attributes It is anticpated that most domains will need both DELEG and traditional NS records published in their parent zone for the foreseeable future. Therefore, EPP servers SHOULD allow clients to configure domain names to have both DELEG records and host objects or host attributes.

Security Considerations Under the initial design of the DELEG record, the security implications of propoerly carrying the record in EPP, and name servers using such information in zones, are similar to the security implications for NS records. If there are later extensions to the DELEG record, those extension may have different security considerations that will need to be documented.

Formal syntax The formal syntax presented here is a complete schema representation of the extension suitable for automated validation of EPP XML instances. <?xml version="1.0" encoding="UTF-8"?> <schema xmlns="http://www.w3.org/2001/XMLSchema" targetNamespace="urn:ietf:params:xml:ns:epp:deleg-0.01" xmlns:deleg="urn:ietf:params:xml:ns:epp:deleg-0.01" xmlns:eppcom="urn:ietf:params:xml:ns:eppcom-1.0" elementFormDefault="qualified"> <annotation> <documentation> Extensible Provisioning Protocol v1.0 extension schema for DELEG records. </documentation> </annotation> <import namespace="urn:ietf:params:xml:ns:eppcom-1.0"/> <element name="infData" type="deleg:containerType"/> <element name="create" type="deleg:containerType"/> <element name="update" type="deleg:updateType"/> <complexType name="updateType"> <sequence> <element name="add" type="deleg:containerType" minOccurs="0"/> <element name="rem" type="deleg:containerType" minOccurs="0"/> </sequence> </complexType> <complexType name="containerType"> <sequence> <element name="deleg" type="deleg:delegType" minOccurs="0" maxOccurs="unbounded"/> </sequence> </complexType> <complexType name="delegType"> <sequence> <element name="params" type="deleg:paramType" minOccurs="0"/> </sequence> <attribute name="priority" type="unsignedShort"/> <attribute name="target" type="eppcom:labelType"/> </complexType> <complexType name="paramType"> <anyAttribute processContents="skip"/> </complexType> </schema>

IANA considerations

XML Namespace This document uses URNs to describe XML namespaces and XML schemas conforming to a registry mechanism described in . The following URI assignment has been made by IANA: Registration for the DELEG namespace: URI: urn:ietf:params:xml:ns:epp:deleg-&VERSION; Registrant Contact: See the author(s) of this document XML: None. Namespace URIs do not represent an XML specification Registration for the DELEG XML schema: URI: urn:ietf:params:xml:schema:epp:deleg-&VERSION; Registrant Contact: See the author(s) of this document XML: See the "" section of this document

EPP Extension Registry The EPP extension described in this document has been registered by the IANA in the Extensions for the "Extensible Provisioning Protocol (EPP)" registry described in . The details of the registration are as follows: Name of Extension: Extensible Provisioning Protocol (EPP) Mapping for DELEG records Document Status: Standards Track Reference: URL of this document Registrant Name and Email Address: See the author(s) of this document TLDs: Any IPR Disclosure: None Status: Active Notes: None