RFC 9095

Extensible Provisioning Protocol (EPP) Domain Name Mapping Extension for Strict Bundling Registration

📅 published July 2021, from ietf

Extensible Provisioning Protocol (EPP) Domain Name Mapping Extension for Strict Bundling Registration 🎀

Okay bestie, here's the title block tea ☕✨

  • RFC number: 9095
  • Stream: Independent Submission, so it came in from outside the usual IETF working groups 💅
  • Category: Informational, which means it is not a Standards Track spec 🌸
  • Date: July 2021 📅
  • ISSN: 2070-1721
  • Authors: J. Yao, L. Zhou, H. Li (CNNIC), N. Kong (Consultant), and J. Xie 🫶
  • Obsoletes / Updates: the title block doesn't list any, so this doc isn't replacing or updating another RFC 💜

Abstract 🌸

Okay so this doc describes an extension of EPP domain name mapping for provisioning and managing strict bundling registration of domain names 🧚. It's specified in XML, and it extends the EPP domain name mapping to give extra features needed for provisioning bundled domain names. It's a nonstandard proprietary extension, so keep that in mind 👀.

Status of This Memo 🎀

This document is not an Internet Standards Track specification. It's published for informational purposes 📖.

This is a contribution to the RFC Series, independently of any other RFC stream. The RFC Editor chose to publish this doc at its discretion, and they make no statement about its value for implementation or deployment 🤷‍♀️. Documents approved for publication by the RFC Editor are not candidates for any level of Internet Standard. See Section 2 of RFC 7841 for the details 🔍.

Want the current status, any errata, or a way to send feedback? Check https://www.rfc-editor.org/info/rfc9095 🌈.

Copyright (c) 2021 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 carefully, since they describe your rights and restrictions with respect to this document 📜✨.

Table of Contents 🍓

   1.  Introduction
   2.  Terminology
   3.  Overview
   4.  Requirement for Bundling Registration of Names
   5.  Object Attributes
     5.1.  RDN
     5.2.  BDN
   6.  EPP Command Mapping
     6.1.  EPP Query Commands
       6.1.1.  EPP <check> Command
       6.1.2.  EPP <info> Command
       6.1.3.  EPP <transfer> Query Command
     6.2.  EPP Transform Commands
       6.2.1.  EPP <create> Command
       6.2.2.  EPP <delete> Command
       6.2.3.  EPP <renew> Command
       6.2.4.  EPP <transfer> Command
       6.2.5.  EPP <update> Command
   7.  Formal Syntax
   8.  Internationalization Considerations
   9.  IANA Considerations
     9.1.  XML Namespace and XML Schema
       9.1.1.  BDN Namespace
       9.1.2.  BDN XML Schema
     9.2.  EPP Extension
   10. Security Considerations
   11. References
     11.1.  Normative References
     11.2.  Informative References
   Acknowledgements
   Authors' Addresses

1. Introduction ✨

Okay so in RFC 4290 [RFC4290], a "variant(s)" is a character or string (or several of them) that gets treated as equivalent to the base character 🫶. In this document, variants are the strings that are treated as equivalent to each other according to the domain name registration policy 💅.

Bundled domain names are the ones that share the same Top-Level Domain (TLD) but have variant second-level labels, or the ones that have identical second-level labels where certain parameters are shared across different TLDs 🎀. For example, the Public Interest Registry has requested to implement bundling of second-level domains for .NGO and .ONG 🌸. So we get two kinds of bundled domain names:

  • The first one is in the form of "V-label.TLD", where the second-level label (V-label) is a variant sharing the same TLD.
  • The second one is in the form of "LABEL.V-tld", where the second-level label (LABEL) stays the same but ends with a different TLD (V-tld), and these different V-tlds are managed by the same entity 🦋.

Bundled domain names normally share some attributes 💖. Policy-wise, bundling can be implemented in three ways:

  • Strict bundling requires all bundled names to share many of the same attributes. When creating, updating, or transferring any of the bundled domain names, all bundled domain names will be created, updated, or transferred atomically ⚡.
  • Partial bundling requires the bundled domain names to be registered by the same registrant 🧑‍💻.
  • Relaxed bundling has no specific requirements on the domain registration 🌈.

This document mainly addresses the strict bundling name registration, so that's our main character 👑.

For name variants, different registries have different policies 🍓. Some registries adopt the policy that variant Internationalized Domain Names (IDNs) should be blocked 🚫. But some registries adopt the policy that variant IDNs identified as equivalent are allocated or delegated to the same registrant 🫶. For example, most registries offering a Chinese Domain Name (CDN) adopt a registration policy where a registrant can apply for an original CDN in any form: Simplified Chinese (SC) form, Traditional Chinese (TC) form, or other variant forms 🧧. The corresponding variant CDN in SC form and in TC form will also be delegated to the same registrant 💅. All variant names in the same TLD share a common set of attributes 🔗. This document mainly discusses the situation in which variant IDNs identified as equivalent are allocated or delegated to the same registrant ✨.

The basic Extensible Provisioning Protocol (EPP) domain name mapping [RFC5731] gives you the facility for single domain name registration 🦋. It does not specify how to register strict bundled names that share many of the attributes 😤.

So to meet those requirements of strict bundled name registration, this document describes an extension of the EPP domain name mapping [RFC5731] for provisioning and managing bundled names 🧚. It's a nonstandard proprietary extension 🙈. This extension is especially useful for registries doing Chinese Domain Name registration 🇨🇳, and it's also useful for other language domain names that have similar issues to Chinese Domain Names 🌏. This document is specified using Extensible Markup Language (XML) 1.0 as described in [W3C.REC-xml-20040204], and XML Schema notation as described in [W3C.REC-xmlschema-1-20041028] and [W3C.REC-xmlschema-2-20041028] 📐.

The EPP core protocol specification [RFC5730] gives a complete description of EPP command and response structures 💜. A thorough understanding of the base protocol specification is necessary to understand the extension mapping described in this document 📚.

This document uses many IDN concepts, so a thorough understanding of IDNs for Application (IDNA, described in [RFC5890], [RFC5891], and [RFC5892]) and the variant approach discussed in [RFC4290] is assumed 🧠.

2. Terminology 💅

Variants in this document are the strings that are treated as equivalent to each other according to the domain name registration policy for certain TLDs 🎀.

Bundled domain names are bundled together according to the domain name registration policy 🌸. For example, many Chinese Domain Name registries follow the principle described in RFC 3743 [RFC3743] 📜. Bundled domain names should belong to the same owner. If bundled domain names are under different TLDs, those TLDs should be managed by the same entity 🫶.

The terms "registered domain name" (RDN) and "bundled domain name" (BDN) are used in this document 🦋. The RDN is the valid domain name that registrants submitted for the initial registration. The BDN is the bundled domain name produced according to the bundled domain name registration policy 🧚. In current practice, the number of BDNs is usually kept at one, according to the registration policy set by the registry 🍓. Both the RDN and BDN specified in this document will be registered via EPP. All other domain names related to the RDN will be blocked 🚫.

The uLabel attribute in this document is used to express the U-label of an Internationalized Domain Name as a series of characters, where non-ASCII characters are represented in the format &#xXXXX;, where XXXX is a Unicode point, using the XML escaping mechanism 🌈. The U-label is defined in [RFC5890]. This document chooses this format of literal HTML ampersand codes, not the expected Unicode character codes 🤓. Unicode characters may not display correctly in some text file readers, while HTML numeric character references are easy for HTML processors 🧩. The implementation following this document should use Unicode characters directly 💖.

This document uses the prefix b-dn for the namespace urn:ietf:params:xml:ns:epp:b-dn throughout 🎀. Implementations cannot assume that any particular prefix is used, and they must employ a namespace-aware XML parser and serializer to interpret and output the XML documents 🙌.

In the examples, C: represents lines sent by a protocol client, and S: represents lines returned by a protocol server 💬. Indentation and spacing in the examples are provided only to illustrate element relationships, and they are not a required feature of this specification ✨.

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

3. Overview 🦋

Domain registries have usually adopted a registration model where metadata relating to a domain name, such as its expiration date and sponsoring registrar, is stored as properties of the domain object 📦. The domain object is then considered an atomic unit of registration, on which operations such as update, renewal, and deletion may be performed 🔧.

Bundled names brought about the need for multiple domain names to be registered and managed as a single package 🎁. In this model, the registry typically accepts a domain registration request (i.e., EPP domain <create> command) containing the domain name to be registered 📨. This domain name is referred to as the RDN in this document 🦋. As part of processing the registration request, the registry generates a set of bundled names related to the RDN, either programmatically or with the guidance of registration policies, and places them in the registration package together with the RDN 🧚.

The bundled names share many properties, such as expiration date and sponsoring registrar, by sharing the same domain object 💖. So when registrants update any property of a domain object within a bundle package, that property will be updated at the same time for all other domain objects in the bundle package 🌸✨.

4. Requirement for Bundling Registration of Names 🎀

okay so the bundled names, whether they look like "V-label.TLD" or "LABEL.V-tld", should share some parameters or attributes that go with domain names 💅 Typically, bundled names share these:

  • Registrar ownership
  • Registration and expiry dates
  • Registrant, admin, billing, and technical contacts
  • Name server association
  • Domain status
  • Applicable grace periods (add grace period, renew grace period, auto-renew grace period, transfer grace period, and redemption grace period) [RFC3915]

Since the domain names are bundled and share the same parameters or attributes, the EPP command should do some processing for these requirements ✨

  • When performing a domain <check> command, either the BDN or RDN can be queried with the EPP command, and it will return the same response 🦋
  • When performing a domain <info> command, either the BDN or RDN can be queried, and the same response will include both BDN and RDN information with the same attributes 🧚
  • When performing a domain <create> command, if the domain name is available, both the BDN and RDN will be registered 🌸
  • When performing a domain <delete> command, either the BDN or RDN will be accepted. If the domain name is registered, both the BDN and RDN will be deleted 💀
  • When performing a domain <renew> command, either the BDN or RDN will be accepted. Upon a successful domain renewal, both the BDN and RDN will have their expiry date extended by the requested term. Upon a successful domain renewal, both the BDN and RDN will conform to the same renew grace period 🍓
  • When performing a domain <transfer> command, either the BDN or RDN will be accepted. Upon successful completion of a domain transfer request, both the BDN and RDN will enter a pendingTransfer status. Upon approval of the transfer request, both the BDN and RDN will be owned and managed by the same new registrant 🔥
  • When performing a domain <update> command, either the BDN or RDN will be accepted. Any modifications to contact associations, name server associations, domain status values, and authorization information will be applied to both the BDN and RDN 👑

5. Object Attributes 💜

okay this extension adds the following extra elements to the EPP domain name mapping [RFC5731], and every one of them gets returned from the <domain:info> command 🫶

5.1. RDN 🌈

The RDN is an ASCII name or an IDN in the A-label [RFC5890] form. In this document, its corresponding element is <b-dn:rdn>. There's an optional attribute "uLabel" on <b-dn:rdn> that shows the U-label [RFC5890] form ✨

For example:

<b-dn:rdn uLabel="&#x5B9E;&#x4F8B;.example"> xn--
   fsq270a.example</b-dn:rdn>

5.2. BDN 🦋

The BDN is an ASCII name or an IDN in the A-label [RFC5890] form, converted from the corresponding BDN. In this document, its corresponding element is <b-dn:bdn>. There's an optional attribute "uLabel" on <b-dn:bdn> that shows the U-label [RFC5890] form 💖

For example:

<b-dn:bdn uLabel="&#x5BE6;&#x4F8B;.example"> xn--
   fsqz41a.example</b-dn:bdn>

6. EPP Command Mapping 🌸

the full EPP syntax and semantics are in the EPP core protocol specification [RFC5730], so go read that if you want the whole story 📖 The command mappings in this section are specifically for provisioning and managing bundled names via EPP 🧚

6.1. EPP Query Commands 🔍

EPP gives you three commands to retrieve domain information. <check> tells you whether a domain object can be provisioned within a repository. <info> gets you the detailed information for a domain object. <transfer> gets you the transfer status information for a domain object 💅

6.1.1. EPP <check> Command ✨

This extension doesn't add any element to the EPP <check> command or the <check> response described in the EPP domain name mapping [RFC5731]. BUT when either the RDN or BDN is sent for a check, the response should contain both RDN and BDN information. It can also give a little explanation in the reason field to let the registrant know the domain name is a produced name based on some bundle domain name policy 🎀

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:chkData
S:        xmlns:domain="urn:ietf:params:xml:ns:domain-1.0">
S:          <domain:cd>
S:           <domain:name avail="1">
S:            xn--fsq270a.example</domain:name>
S:          </domain:cd>
S:          <domain:cd>
S:            <domain:name avail="1">
S:              xn--fsqz41a.example
S:            </domain:name>
S:            <domain:reason>This associated domain name is
S:              a produced name based on bundle name policy.
S:            </domain:reason>
S:          </domain:cd>
S:      </domain:chkData>
S:    </resData>
S:    <trID>
S:      <clTRID>ABC-12345</clTRID>
S:      <svTRID>54322-XYZ</svTRID>
S:    </trID>
S:  </response>
S:</epp>

                 Figure 1: Example <check> Response

6.1.2. EPP <info> Command 🧁

This extension doesn't add any element to the EPP <info> command described in the EPP domain mapping [RFC5731]. However, extra elements are defined for the <info> response 💖

When an <info> command has been processed successfully, the EPP <resData> element should contain the child elements described in the EPP domain mapping [RFC5731]. Also, unless some registration policy has special processing, the EPP <extension> element should contain a child <b-dn:infData> element that identifies the extension namespace, if the domain object has data associated with this extension and based on its registration policy. The <b-dn:infData> element contains the <b-dn:bundle>, which has these child elements:

  • A <b-dn:rdn> element that contains the RDN, along with the attribute described below.
  • An optional <b-dn:bdn> element that contains the BDN, along with the attribute described below.

The elements above have this attribute:

  • An optional "uLabel" attribute that represents the U-label of the element.
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>xn--fsq270a.example</domain:name>
S:        <domain:roid>58812678-domain</domain:roid>
S:        <domain:status s="ok"/>
S:        <domain:registrant>123</domain:registrant>
S:        <domain:contact type="admin">123</domain:contact>
S:        <domain:contact type="tech">123</domain:contact>
S:        <domain:ns>
S:          <domain:hostObj>ns1.example.cn
S:          </domain:hostObj>
S:        </domain:ns>
S:        <domain:clID>ClientX</domain:clID>
S:        <domain:crID>ClientY</domain:crID>
S:        <domain:crDate>2019-04-03T22:00:00.0Z
S:        </domain:crDate>
S:        <domain:exDate>2022-04-03T22:00:00.0Z
S:        </domain:exDate>
S:        <domain:authInfo>
S:          <domain:pw>2fooBAR</domain:pw>
S:        </domain:authInfo>
S:      </domain:infData>
S:    </resData>
S:    <extension>
S:      <b-dn:infData
S:        xmlns:b-dn="urn:ietf:params:xml:ns:epp:b-dn">
S:        <b-dn:bundle>
S:          <b-dn:rdn uLabel="&#x5B9E;&#x4F8B;.example">
S:            xn--fsq270a.example
S:          </b-dn:rdn>
S:          <b-dn:bdn uLabel="&#x5BE6;&#x4F8B;.example">
S:            xn--fsqz41a.example
S:          </b-dn:bdn>
S:        </b-dn:bundle>
S:      </b-dn:infData>
S:    </extension>
S:    <trID>
S:      <clTRID>ABC-12345</clTRID>
S:      <svTRID>54322-XYZ</svTRID>
S:    </trID>
S:  </response>
S:</epp>

         Figure 2: Example <info> Response for an Authorized Client

The <info> response for the unauthorized client hasn't changed, so check [RFC5731] for the details 🙈

An EPP error response must be returned if an <info> command can't be processed for any reason 😭

6.1.3. EPP <transfer> Query Command 🦋

This extension doesn't add any element to the EPP <transfer> command or the <transfer> response described in the EPP domain mapping [RFC5731]. Nothing new here, bestie 💅

6.2. EPP Transform Commands ⭐

EPP gives you five commands to transform domain objects. <create> creates an instance of a domain object. <delete> deletes an instance of a domain object. <renew> extends the validity period of a domain object. <transfer> manages domain object sponsorship changes. <update> changes information associated with a domain object 🔥

When these commands are processed successfully, the EPP <resData> element should contain the child elements described in the EPP domain mapping [RFC5731]. Unless some registration policy has special processing, this EPP <extension> element should contain the <b-dn:bundle>, which has these child elements:

  • A <b-dn:rdn> element that contains the RDN, along with the attribute described below.
  • An optional <b-dn:bdn> element that contains the BDN, along with the attribute described below.

The elements above have this attribute:

  • An optional "uLabel" attribute that represents the U-label of the element.

6.2.1. EPP <create> Command ✨

okay so this extension adds extra stuff to the EPP <create> command from the EPP domain name mapping [RFC5731] so you can register bundled names 🎀

on top of the usual EPP command elements from [RFC5731], the <create> command shall contain an <extension> element 💅 unless some registration policy has some special processing, that <extension> should hold a child <b-dn:create> element (which identifies the bundle namespace) and a child <b-dn:rdn> element (the U-label form of the registered domain name, tagged with the "uLabel" attribute) 🦋 the U-label is there so registrants can read it easily and registrars and registries can debug it easily 🤓

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>xn--fsq270a.example</domain:name>
C:        <domain:period unit="y">2</domain:period>
C:        <domain:registrant>123</domain:registrant>
C:        <domain:contact type="admin">123</domain:contact>
C:        <domain:contact type="tech">123</domain:contact>
C:        <domain:authInfo>
C:          <domain:pw>2fooBAR</domain:pw>
C:        </domain:authInfo>
C:      </domain:create>
C:    </create>
C:    <extension>
C:      <b-dn:create
C:        xmlns:b-dn="urn:ietf:params:xml:ns:epp:b-dn">
C:        <b-dn:rdn uLabel="&#x5B9E;&#x4F8B;.example">
C:          xn--fsq270a.example
C:        </b-dn:rdn>
C:      </b-dn:create>
C:    </extension>
C:    <clTRID>ABC-12345</clTRID>
C:  </command>
C:</epp>

Figure 3: Example <create> Command

when a <create> command has been processed successfully, the EPP <creData> element must contain child elements as described in [RFC5731] 🌸 on top of that, unless some registration policy has some special processing, the EPP <extension> element should contain a child <b-dn:creData> element that identifies the extension namespace, but only if the domain object has data tied to this extension and based on its registration policy 💖 the <b-dn:creData> element holds the <b-dn:bundle> element 🧚

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:creData
S:        xmlns:domain="urn:ietf:params:xml:ns:domain-1.0">
S:        <domain:name>xn--fsq270a.example</domain:name>
S:        <domain:crDate>2019-04-03T22:00:00.0Z</domain:crDate>
S:        <domain:exDate>2021-04-03T22:00:00.0Z</domain:exDate>
S:      </domain:creData>
S:    </resData>
S:    <extension>
S:      <b-dn:creData
S:        xmlns:b-dn="urn:ietf:params:xml:ns:epp:b-dn">
S:        <b-dn:bundle>
S:          <b-dn:rdn uLabel="&#x5B9E;&#x4F8B;.example">
S:            xn--fsq270a.example
S:          </b-dn:rdn>
S:          <b-dn:bdn uLabel="&#x5BE6;&#x4F8B;.example" >
S:            xn--fsqz41a.example
S:          </b-dn:bdn>
S:        </b-dn:bundle>
S:      </b-dn:creData>
S:    </extension>
S:    <trID>
S:      <clTRID>ABC-12345</clTRID>
S:      <svTRID>54322-XYZ</svTRID>
S:    </trID>
S:  </response>
S:</epp>

Figure 4: Example <create> Response

an EPP error response must be returned if a <create> command cannot be processed for any reason 🙈

6.2.2. EPP <delete> Command 🍓

this extension doesn't add any element to the EPP <delete> command from [RFC5731] 💅 BUT it does define extra elements for the <delete> response, so pay attention to that part 👀

when a <delete> command has been processed successfully, the EPP <delData> element must contain child elements as described in [RFC5731] 🌈 and unless some registration policy has some special processing, the EPP <extension> element should contain a child <b-dn:delData> element that identifies the extension namespace, if the domain object has data tied to this extension and based on its registration policy 🦋 the <b-dn:delData> element should contain the <b-dn:bundle> element ✨

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:    <extension>
S:      <b-dn:delData
S:        xmlns:b-dn="urn:ietf:params:xml:ns:epp:b-dn">
S:        <b-dn:bundle>
S:          <b-dn:rdn uLabel="&#x5B9E;&#x4F8B;.example">
S:            xn--fsq270a.example
S:          </b-dn:rdn>
S:          <b-dn:bdn uLabel="&#x5BE6;&#x4F8B;.example">
S:            xn--fsqz41a.example
S:          </b-dn:bdn>
S:        </b-dn:bundle>
S:      </b-dn:delData>
S:    </extension>
S:    <trID>
S:      <clTRID>ABC-12345</clTRID>
S:      <svTRID>54321-XYZ</svTRID>
S:    </trID>
S:  </response>
S:</epp>

Figure 5: Example <delete> Response

an EPP error response must be returned if a <delete> command cannot be processed for any reason 💀

6.2.3. EPP <renew> Command 🔥

this extension doesn't add any element to the EPP <renew> command from [RFC5731] 🫶 but here's the tea: when either the RDN or the BDN is sent for renewal, the response should contain both the RDN and BDN info 💜 when the command succeeds, the EPP <extension> element shall be contained in the response if the domain object has data tied to bundled names 🌸 and unless some registration policy has some special processing, that <extension> should contain the <b-dn:renData>, which holds the <b-dn:bundle> element 👑

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:renData
S:        xmlns:domain="urn:ietf:params:xml:ns:domain-1.0">
S:        <domain:name>xn--fsq270a.example</domain:name>
S:        <domain:exDate>2022-04-03T22:00:00.0Z</domain:exDate>
S:      </domain:renData>
S:    </resData>
S:    <extension>
S:      <b-dn:renData
S:        xmlns:b-dn="urn:ietf:params:xml:ns:epp:b-dn">
S:        <b-dn:bundle>
S:          <b-dn:rdn uLabel="&#x5B9E;&#x4F8B;.example">
S:            xn--fsq270a.example
S:          </b-dn:rdn>
S:          <b-dn:bdn uLabel="&#x5BE6;&#x4F8B;.example" >
S:            xn--fsqz41a.example
S:          </b-dn:bdn>
S:        </b-dn:bundle>
S:      </b-dn:renData>
S:    </extension>
S:    <trID>
S:      <clTRID>ABC-12345</clTRID>
S:      <svTRID>54322-XYZ</svTRID>
S:    </trID>
S:  </response>
S:</epp>

Figure 6: Example <renew> Response

6.2.4. EPP <transfer> Command 🦋

this extension doesn't add any element to the EPP <transfer> command from [RFC5731] ✨ however, extra elements are defined for the <transfer> response in the EPP object mapping, so keep your eyes peeled 👀 when the command has been processed successfully, the EPP <extension> element shall be contained in the response if the domain object has data tied to bundled names 🎀 unless some registration policy has some special processing, this <extension> should contain the <b-dn:trnData>, which holds the <b-dn:bundle> element 🌈

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="1001">
S:      <msg>Command completed successfully; action pending</msg>
S:    </result>
S:    <resData>
S:      <domain:trnData
S:        xmlns:domain="urn:ietf:params:xml:ns:domain-1.0">
S:        <domain:name>xn--fsq270a.example</domain:name>
S:        <domain:trStatus>pending</domain:trStatus>
S:        <domain:reID>ClientX</domain:reID>
S:        <domain:reDate>2021-04-03T22:00:00.0Z</domain:reDate>
S:        <domain:acID>ClientY</domain:acID>
S:        <domain:acDate>2021-04-08T22:00:00.0Z</domain:acDate>
S:        <domain:exDate>2022-04-03T22:00:00.0Z</domain:exDate>
S:      </domain:trnData>
S:    </resData>
S:    <extension>
S:      <b-dn:trnData
S:        xmlns:b-dn="urn:ietf:params:xml:ns:epp:b-dn">
S:        <b-dn:bundle>
S:          <b-dn:rdn uLabel="&#x5B9E;&#x4F8B;.example">
S:            xn--fsq270a.example
S:          </b-dn:rdn>
S:          <b-dn:bdn uLabel="&#x5BE6;&#x4F8B;.example">
S:            xn--fsqz41a.example
S:          </b-dn:bdn>
S:        </b-dn:bundle>
S:      </b-dn:trnData>
S:    </extension>
S:    <trID>
S:      <clTRID>ABC-12345</clTRID>
S:      <svTRID>54322-XYZ</svTRID>
S:    </trID>
S:  </response>
S:</epp>

Figure 7: Example <transfer> Response

6.2.5. EPP <update> Command 🧚

this extension doesn't add any element to the EPP <update> command from [RFC5731] 💅 but additional elements are defined for the <update> response in the EPP object mapping, so that's where the new stuff lives 🍓 when the command has been processed successfully, the EPP <extension> element shall be contained in the response if the domain object has data tied to bundled names 💖 and unless some registration policy has some special processing, this EPP <extension> element should contain the <b-dn:upData>, which holds the <b-dn:bundle> element 🫶

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:    <extension>
S:      <b-dn:upData
S:        xmlns:b-dn="urn:ietf:params:xml:ns:epp:b-dn">
S:        <b-dn:bundle>
S:          <b-dn:rdn uLabel="&#x5B9E;&#x4F8B;.example" >
S:            xn--fsq270a.example
S:          </b-dn:rdn>
S:          <b-dn:bdn uLabel="&#x5BE6;&#x4F8B;.example">
S:            xn--fsqz41a.example
S:          </b-dn:bdn>
S:        </b-dn:bundle>
S:      </b-dn:upData>
S:    </extension>
S:    <trID>
S:      <clTRID>ABC-12345</clTRID>
S:      <svTRID>54322-XYZ</svTRID>
S:    </trID>
S:  </response>
S:</epp>

Figure 8: Example <update> Response

7. Formal Syntax ✨

okay bestie, this part is the actual XML Schema for bundled names, and it's the thing validators check your EPP XML against 💅 It's the complete schema, so a tool can check instances automatically. The <CODE BEGINS> and <CODE ENDS> lines are just markers for URI registration, and they aren't part of the schema itself 🧚

<CODE BEGINS>

<?xml version="1.0" encoding="UTF-8"?>

<schema targetNamespace="urn:ietf:params:xml:ns:epp:b-dn"
  xmlns:b-dn="urn:ietf:params:xml:ns:epp:b-dn"
  xmlns:eppcom="urn:ietf:params:xml:ns:eppcom-1.0"
  xmlns="http://www.w3.org/2001/XMLSchema"
  elementFormDefault="qualified">

<!--
  Import common element types.
-->
<import namespace="urn:iana:xml:ns:eppcom-1.0"/>

<annotation>
  <documentation>
    Extensible Provisioning Protocol v1.0
    Bundle Domain Extension Schema v1.0
  </documentation>
</annotation>

<!--
  Child elements found in EPP commands.
-->
<element name="create" type="b-dn:createDataType"/>

<!--
  Child elements of the <b-dn:create> command.
  All elements must be present at time of creation
-->
<complexType name="createDataType">
  <sequence>
    <element name="rdn" type="b-dn:rdnType"
      minOccurs="0"/>
  </sequence>
</complexType>

<!--
  Child response elements in <b-dn:infData>, <b-dn:delData>,
  <b-dn:creData>, <b-dn:renData>, <b-dn:trnData> and <b-dn:upData>.
-->
<element name="infData" type="b-dn:bundleDataType"/>
<element name="delData" type="b-dn:bundleDataType"/>
<element name="creData" type="b-dn:bundleDataType"/>
<element name="renData" type="b-dn:bundleDataType"/>
<element name="trnData" type="b-dn:bundleDataType"/>
<element name="upData" type="b-dn:bundleDataType"/>

<complexType name="bundleDataType">
  <sequence>
    <element name="bundle" type="b-dn:bundleType" />
  </sequence>
</complexType>

<complexType name="bundleType">
  <sequence>
    <element name="rdn" type="b-dn:rdnType" />
    <element name="bdn" type="b-dn:rdnType"
      minOccurs="0" maxOccurs="unbounded" />
  </sequence>
</complexType>

<complexType name="rdnType">
  <simpleContent>
    <extension base="eppcom:labelType">
      <attribute name="uLabel" type="eppcom:labelType"/>
    </extension>
  </simpleContent>
</complexType>

<!--
  End of schema.
-->
</schema>

<CODE ENDS>

8. Internationalization Considerations 🌸

okay so EPP is written in XML, and XML can handle the whole Unicode character set 🌈 The compact way to store it is UTF-8, and conformant XML processors recognize both UTF-8 and UTF-16. XML does let you pick another encoding with the encoding attribute in the <?xml?> declaration, but UTF-8 is recommended, so that's the move 💖

And because this is an extension of the EPP domain name mapping, the elements and element content in this document have to follow the same internationalization rules as the higher-layer domain and core protocol structures in any XML instance that uses this extension. Main character energy for consistency 👑

9. IANA Considerations 🎀

9.1. XML Namespace and XML Schema

okay, the namespaces and schemas here are written as URNs, and they follow the registry mechanism from [RFC3688] 🦋

9.1.1. BDN Namespace

IANA went ahead and assigned the BDN namespace in the "ns" subregistry of the "IETF XML Registry", with this document as the reference ✨

URI:  urn:ietf:params:xml:ns:epp:b-dn
Registrant Contact:  See the "Authors' Addresses" section of this
   document.
XML:  None.  The namespace URI does not represent an XML
   specification.

9.1.2. BDN XML Schema

Then there's the BDN XML schema, which IANA put in the "schema" subregistry of the "IETF XML Registry", again with this document as the reference 🧚

URI:  urn:ietf:params:xml:schema:epp:b-dn
Registrant Contact:  See the "Authors' Addresses" section of this
   document.
XML:  See the "Formal Syntax" section of this document.

9.2. EPP Extension

IANA also registered this EPP extension in the "Extensions for the Extensible Provisioning Protocol (EPP)" registry from [RFC7451]. Here's the whole registration, no cap 💅

Name of Extension:  "Domain Name Mapping Extension for Strict
   Bundling Registration"
Document Status:  Informational
Reference:  This document
Registrant Name and Email Address:  See the "Authors' Addresses"
   section of this document.
TLDs:  Any
IPR Disclosure:  https://datatracker.ietf.org/ipr/2479
Status:  Active
Notes:  None

10. Security Considerations 💀

okay this section is serious, so read it carefully bestie 🚨

Normally the EPP server only gets connected to by the authorized EPP client, and that client knows whether the server supports this extension through out-of-band service. The EPP client should avoid sending this extension to a server that doesn't implement it. If a client that supports this document sends a request to a server that doesn't support it, the server returns result code 2103, as described in Section 3 of [RFC5730]. Here's what Section 3 of [RFC5730] says about result code 2103 🙈

|  2103 "Unimplemented extension"
|
|  This response code MUST be returned when a server receives a valid
|  EPP command element that contains a protocol command extension
|  that is not implemented by the server.

Some registries and registrars have more than 15 years' experience with bundled registration of domain names (especially Chinese Domain Names), and they haven't found any significant security issues 🙌 Still, one principle that registries and registrars should tell registrants is that bundled domain names get created, transferred, updated, and deleted together as a group. Registrants should keep this in mind whenever they operate on these domain names. [RFC5730] also brings in some security considerations of its own.

⚠️ The big one: this document doesn't say whether bundled domain names share a key for Delegation Signer (DS) and/or DNS Public Key (DNSKEY) resource records. That's up to the DNS administrator, who can choose whether DS/DNSKEY information gets shared. If a DS/DNSKEY key is shared, then the bundled domain names share fate if there's a key compromise. Yikes 😭

11. References 📚

11.1. Normative References

11.2. Informative References

Acknowledgements 🫶

The authors especially thank the authors of [RFC5730] and [RFC5731], and the following members of the China Internet Network Information Center (CNNIC): Weiping Yang, Chao Qi. 💜

Useful comments came from John Klensin, Scott Hollenbeck, Patrick Mevzek, Edward Lewis, Wil Tan, and Adrian Farrel. Iconic crew 👑

Authors' Addresses 🦋

Jiankang Yao
CNNIC
4 South 4th Street, Zhongguancun, Haidian District
Beijing
Beijing, 100190
China

Phone: +86 10 5881 3007
Email: yaojk@cnnic.cn


Linlin Zhou
CNNIC
4 South 4th Street, Zhongguancun, Haidian District
Beijing
Beijing, 100190
China

Phone: +86 10 5881 2677
Email: zhoulinlin@cnnic.cn


Hongtao Li
CNNIC
4 South 4th Street, Zhongguancun, Haidian District
Beijing
Beijing, 100190
China

Email: lihongtao@cnnic.cn


Ning Kong
Consultant

Email: ietfing@gmail.com


Jiagui Xie

Email: jiagui1984@163.com
📦 where this page comes from