Network Working Group
Internet Engineering Task Force (IETF) D. Belyavskiy
Internet-Draft
Intended status:
Request for Comments: 9873
Category: Standards Track J. Gould
Expires: 20 November 2025
ISSN: 2070-1721 VeriSign, Inc.
S. Hollenbeck
Verisign Labs
19 May
September 2025
Additional Email Address Extension for the Extensible Provisioning
Protocol (EPP)
draft-ietf-regext-epp-eai-27
Abstract
The Extensible Provisioning Protocol (EPP) does not natively support
internationalized email addresses because the specifications for
these addresses did not exist when EPP was developed. This document
describes a command-response extension that adds support for
associating an additional email address with an EPP contact object.
That additional email address can be either an internationalized
email address or an all-ASCII address.
Status of This Memo
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This Internet-Draft will expire on 20 November 2025.
https://www.rfc-editor.org/info/rfc9873.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Conventions Used in This Document . . . . . . . . . . . . 4
2. Email Address Specification . . . . . . . . . . . . . . . . . 4
3. Additional Email Address Element . . . . . . . . . . . . . . 5
4. Extension Considerations . . . . . . . . . . . . . . . . . . 5
4.1. Signaling Client and Server Support . . . . . . . . . . . 5
4.2. Extension Behavior . . . . . . . . . . . . . . . . . . . 5
4.2.1. Extension Negotiated . . . . . . . . . . . . . . . . 6
4.2.2. Extension Not Negotiated . . . . . . . . . . . . . . 6
5. EPP Command Mapping . . . . . . . . . . . . . . . . . . . . . 7
5.1. EPP Query Commands . . . . . . . . . . . . . . . . . . . 7
5.1.1. EPP <check> Command . . . . . . . . . . . . . . . . . 7
5.1.2. EPP <info> Command . . . . . . . . . . . . . . . . . 7
5.1.3. EPP <transfer> Query Command . . . . . . . . . . . . 11
5.2. EPP Transform Commands . . . . . . . . . . . . . . . . . 11
5.2.1. EPP <create> Command . . . . . . . . . . . . . . . . 11
5.2.2. EPP <delete> Command . . . . . . . . . . . . . . . . 15
5.2.3. EPP <renew> Command . . . . . . . . . . . . . . . . . 15
5.2.4. EPP <transfer> Command . . . . . . . . . . . . . . . 15
5.2.5. EPP <update> Command . . . . . . . . . . . . . . . . 15
6. Formal Syntax . . . . . . . . . . . . . . . . . . . . . . . . 17
6.1. EPP Additional Email Address Extension Schema . . . . . . 17
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 18
7.1. XML Namespace . . . . . . . . . . . . . . . . . . . . . . 18
7.2. EPP Extension Registry . . . . . . . . . . . . . . . . . 19
8. Security Considerations . . . . . . . . . . . . . . . . . . . 20
9. Privacy Considerations . . . . . . . . . . . . . . . . . . . 21
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 21
10.1. Normative References . . . . . . . . . . . . . . . . . . 21
10.2. Informative References . . . . . . . . . . . . . . . . . 23
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 28
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 28
1. Introduction
The framework for internationalized email addresses is described in
[RFC6530]. This document describes an Extensible Provisioning
Protocol (EPP) [RFC5730] command-response extension that adds support
for adding a second email address to the EPP contact object [RFC5733]
mapping. mapping
[RFC5733]. The syntax for the email address associated with the base
contact object is described in Section 2.6 of [RFC5733]. The second
email address can be either an ASCII-only email address or an
internationalized,
internationalized SMTPUTF8 [RFC6530] email address. address [RFC6530]. This second
address can be used to identify an alternate ASCII-only email address
for use in case of primary address delivery issues. It can also be
used to identify an SMTPUTF8 address for contact purposes, in which
case the ASCII-only address can be used in case of SMTPUTF8 address
delivery issues.
While this extension adds support for an additional email address to
contact objects, and that additional email address can be an SMTPUTF8
address, it does not in any way update or change any other EPP
extension that includes an email address. Adding support for
SMTPUTF8 addresses to those extensions will require an update to the
relevant extension specifications. In cases where a contact object
contains two email addresses, all users of these addresses should be
aware that either address may be forwarded to the other. This
implies that a message sent to an all-ASCII address may receive a
reply from an SMTPUTF8 address, address or vice versa.
1.1. 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 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
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.
In examples, "C:" represents lines sent by a protocol client client, and
"S:" represents lines returned by a protocol server. Indentation and
white space in the examples are provided only to illustrate element
relationships and are not REQUIRED in the protocol.
The XML namespace prefix "addlEmail" is used for the namespace
"urn:ietf:params:xml:ns:epp:addlEmail-1.0", but implementations MUST
NOT depend on it and instead employ a proper namespace-aware XML
parser and serializer to interpret and output the XML documents.
2. Email Address Specification
The EPP contact object mapping [RFC5733] normatively references
[RFC5322] as the specification for email address syntax. That
specification does not include support for internationalized email
addresses. RFC 6530 [RFC6530] provides an overview and describes the
framework for internationalized email. SMTPUTF8 email address syntax
is described in Section 3.3 of [RFC6531]. [RFC6531] extends the
Mailbox, Local-part Local-part, and Domain ABNF rules in [RFC5321] to support
"UTF8-non-ascii", defined
"UTF8-non-ascii" (defined in Section 3.1 of [RFC6532], [RFC6532]) for the local-
part and U-label, defined to support U-label (defined in Section 2.3.2.1 of [RFC5890], [RFC5890])
for the domain. The validation rules described in RFC 6531 [RFC6531] MUST be
followed when processing internationalized email addresses associated
with this extension.
3. Additional Email Address Element
A second email address can be set using the <addlEmail:addlEmail>
element with the command and response extensions defined in
Section 5. The <addlEmail:addlEmail> element contains the following
child element:
<addlEmail:email>: An element following the syntax in Section 2 for
defining a second ASCII or SMTPUTF8 address. An empty
<addlEmail:email/> element unsets the second email address in the
Update Command (Section 5.2.5) and indicates the second email is
not set in the Info Response (Section 5.1.2). The
<addlEmail:email> element contains an OPTIONAL "primary"
attribute that can be used to indicate that the extension email
address should be treated as the primary email address for the
extended contact object. The "primary" attribute MUST NOT be
present if the <addlEmail:email> is empty.
Additional email address considerations:
* The value set for the <contact:disclose><contact:email/> "flag"
attribute (described in Section 2.9 of RFC 5733 [RFC5733]) MUST also be
applied to all additional email addresses that are added by a
contact extension.
* Any address included in an extension is intended to be an
additional address that's that is associated only with the primary
<contact:email> address, and that support for any other additional
email addresses MUST explicitly describe how the additional
addresses are associated with the existing addresses.
4. Extension Considerations
4.1. Signaling Client and Server Support
As described in Section 2.4 of [RFC5730], the client and the server
can signal support for the extension using a namespace URI in the
login and greeting extension services services, respectively. The namespace
URI "urn:ietf:params:xml:ns:epp:addlEmail-1.0" is used to signal
support for the extension. The client includes the namespace URI in
an <svcExtension> <extURI> element of the [RFC5730] <login> Command. command [RFC5730].
The server includes the namespace URI in an <svcExtension> <extURI>
element of the [RFC5730] greeting. greeting [RFC5730].
4.2. Extension Behavior
4.2.1. Extension Negotiated
If both client and server have indicated support for SMTPUTF8
addresses during session establishment, they MUST be able to process
an SMTPUTF8 address in any extended contact object during the
established EPP session. Server and client obligations when this
extension has been successfully negotiated in the EPP session are
described below.
The server MUST satisfy the following obligations when support for
this extension has been negotiated:
* Accept SMTPUTF8 compliant SMTPUTF8-compliant addresses for the extended contact
object in the EPP session.
* Support email address validation based on the SMTPUTF8 validation
rules defined in Section 2 2.
* Storage of email properties that support internationalized
characters.
* Return SMTPUTF8 compliant SMTPUTF8-compliant addresses for the extended contact
object in EPP responses.
* Support the SMTP extension for internationalized email described
in [RFC6531] when sending or receiving email.
The client MUST satisfy the following obligations when support for
this extension has been negotiated:
* Provide SMTPUTF8 compliant SMTPUTF8-compliant addresses for the extended contact
object in the EPP session.
* Accept SMTPUTF8 compliant SMTPUTF8-compliant addresses for the extended contact
object in EPP responses.
* Support the SMTP extension for internationalized email described
in [RFC6531] when sending or receiving email.
4.2.2. Extension Not Negotiated
An extended contact object MUST NOT be provided or returned by either
an EPP client or an EPP server when support for this extension is not
successfully negotiated at the start of an EPP session.
5. EPP Command Mapping
A detailed description of the EPP syntax and semantics can be found
in the EPP core protocol specification [RFC5730]. This section
defines the provisioning of an alternate email address.
5.1. EPP Query Commands
EPP provides three commands to retrieve object information: <check>
to determine if an object can be provisioned, <info> to retrieve
information associated with an object, and <transfer> to retrieve
object-transfer status information.
5.1.1. EPP <check> Command
This extension does not add any elements to the EPP <check> command
or <check> response described in [RFC5730].
5.1.2. EPP <info> Command
This extension does not add any elements to the EPP <info> command
response described in [RFC5730].
If the query was is successful, the server replies with an
<addlEmail:addlEmail> element (Section 3) along with the regular EPP
<resData>.
The following is an example <info> contact response using the
<addlEmail:addlEmail> extension with no alternate email address:
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: <contact:infData
S: xmlns:contact="urn:ietf:params:xml:ns:contact-1.0">
S: <contact:id>sh8013</contact:id>
S: <contact:roid>SH8013-REP</contact:roid>
S: <contact:status s="linked"/>
S: <contact:status s="clientDeleteProhibited"/>
S: <contact:postalInfo type="int">
S: <contact:name>John Doe</contact:name>
S: <contact:org>Example Inc.</contact:org>
S: <contact:addr>
S: <contact:street>123 Example Dr.</contact:street>
S: <contact:street>Suite 100</contact:street>
S: <contact:city>Dulles</contact:city>
S: <contact:sp>VA</contact:sp>
S: <contact:pc>20166-6503</contact:pc>
S: <contact:cc>US</contact:cc>
S: </contact:addr>
S: </contact:postalInfo>
S: <contact:voice x="1234">+1.7035555555</contact:voice>
S: <contact:fax>+1.7035555556</contact:fax>
S: <contact:email>jdoe@example.com</contact:email>
S: <contact:clID>ClientY</contact:clID>
S: <contact:crID>ClientX</contact:crID>
S: <contact:crDate>1999-04-03T22:00:00.0Z</contact:crDate>
S: <contact:upID>ClientX</contact:upID>
S: <contact:upDate>1999-12-03T09:00:00.0Z</contact:upDate>
S: <contact:trDate>2000-04-08T09:00:00.0Z</contact:trDate>
S: <contact:authInfo>
S: <contact:pw>2fooBAR</contact:pw>
S: </contact:authInfo>
S: <contact:disclose flag="0">
S: <contact:voice/>
S: <contact:email/>
S: </contact:disclose>
S: </contact:infData>
S: </resData>
S: <extension>
S: <addlEmail:addlEmail
S: xmlns:addlEmail="urn:ietf:params:xml:ns:epp:addlEmail-1.0">
S: <addlEmail:email/>
S: </addlEmail:addlEmail>
S: </extension>
S: <trID>
S: <clTRID>ABC-12345</clTRID>
S: <svTRID>54322-XYZ</svTRID>
S: </trID>
S: </response>
S:</epp>
Figure 1: Example <info> contact response using Contact Response Using the
<addlEmail:addlEmail> extension Extension with no alternate email address No Alternate Email Address
The following is an example <info> contact response using the
<addlEmail:addlEmail> extension with an ASCII alternate email
address:
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: <contact:infData
S: xmlns:contact="urn:ietf:params:xml:ns:contact-1.0">
S: <contact:id>sh8013</contact:id>
S: <contact:roid>SH8013-REP</contact:roid>
S: <contact:status s="linked"/>
S: <contact:status s="clientDeleteProhibited"/>
S: <contact:postalInfo type="int">
S: <contact:name>John Doe</contact:name>
S: <contact:org>Example Inc.</contact:org>
S: <contact:addr>
S: <contact:street>123 Example Dr.</contact:street>
S: <contact:street>Suite 100</contact:street>
S: <contact:city>Dulles</contact:city>
S: <contact:sp>VA</contact:sp>
S: <contact:pc>20166-6503</contact:pc>
S: <contact:cc>US</contact:cc>
S: </contact:addr>
S: </contact:postalInfo>
S: <contact:voice x="1234">+1.7035555555</contact:voice>
S: <contact:fax>+1.7035555556</contact:fax>
S: <contact:email>jdoe@example.com</contact:email>
S: <contact:clID>ClientY</contact:clID>
S: <contact:crID>ClientX</contact:crID>
S: <contact:crDate>1999-04-03T22:00:00.0Z</contact:crDate>
S: <contact:upID>ClientX</contact:upID>
S: <contact:upDate>1999-12-03T09:00:00.0Z</contact:upDate>
S: <contact:trDate>2000-04-08T09:00:00.0Z</contact:trDate>
S: <contact:authInfo>
S: <contact:pw>2fooBAR</contact:pw>
S: </contact:authInfo>
S: <contact:disclose flag="0">
S: <contact:voice/>
S: <contact:email/>
S: </contact:disclose>
S: </contact:infData>
S: </resData>
S: <extension>
S: <addlEmail:addlEmail
S: xmlns:addlEmail="urn:ietf:params:xml:ns:epp:addlEmail-1.0">
S: <addlEmail:email>jdoe-alt@example.net</addlEmail:email>
S: </addlEmail:addlEmail>
S: </extension>
S: <trID>
S: <clTRID>ABC-12345</clTRID>
S: <svTRID>54322-XYZ</svTRID>
S: </trID>
S: </response>
S:</epp>
Figure 2: Example <info> contact response using Contact Response Using the
<addlEmail:addlEmail> extension Extension with an ASCII alternate email
address Alternate Email
Address
The following is an example <info> contact response using the
<addlEmail:addlEmail> extension with an SMTPUTF8 primary email
address:
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: <contact:infData
S: xmlns:contact="urn:ietf:params:xml:ns:contact-1.0">
S: <contact:id>sh8013</contact:id>
S: <contact:roid>SH8013-REP</contact:roid>
S: <contact:status s="linked"/>
S: <contact:status s="clientDeleteProhibited"/>
S: <contact:postalInfo type="int">
S: <contact:name>John Doe</contact:name>
S: <contact:org>Example Inc.</contact:org>
S: <contact:addr>
S: <contact:street>123 Example Dr.</contact:street>
S: <contact:street>Suite 100</contact:street>
S: <contact:city>Dulles</contact:city>
S: <contact:sp>VA</contact:sp>
S: <contact:pc>20166-6503</contact:pc>
S: <contact:cc>US</contact:cc>
S: </contact:addr>
S: </contact:postalInfo>
S: <contact:voice x="1234">+1.7035555555</contact:voice>
S: <contact:fax>+1.7035555556</contact:fax>
S: <contact:email>jdoe@example.com</contact:email>
S: <contact:clID>ClientY</contact:clID>
S: <contact:crID>ClientX</contact:crID>
S: <contact:crDate>1999-04-03T22:00:00.0Z</contact:crDate>
S: <contact:upID>ClientX</contact:upID>
S: <contact:upDate>1999-12-03T09:00:00.0Z</contact:upDate>
S: <contact:trDate>2000-04-08T09:00:00.0Z</contact:trDate>
S: <contact:authInfo>
S: <contact:pw>2fooBAR</contact:pw>
S: </contact:authInfo>
S: <contact:disclose flag="0">
S: <contact:voice/>
S: <contact:email/>
S: </contact:disclose>
S: </contact:infData>
S: </resData>
S: <extension>
S: <addlEmail:addlEmail
S: xmlns:addlEmail="urn:ietf:params:xml:ns:epp:addlEmail-1.0">
S: <addlEmail:email
primary="true">麥克風@example.com</addlEmail:email>
S: </addlEmail:addlEmail>
S: </extension>
S: <trID>
S: <clTRID>ABC-12345</clTRID>
S: <svTRID>54322-XYZ</svTRID>
S: </trID>
S: </response>
S:</epp>
Figure 3: Example <info> contact response using Contact Response Using the
<addlEmail:addlEmail> extension Extension with an SMTPUTF8 primary email
address Primary Email
Address
5.1.3. EPP <transfer> Query Command
This extension does not add any elements to the EPP <transfer> query
command or <transfer> query response described in [RFC5730].
5.2. EPP Transform Commands
EPP provides five commands to transform objects: <create> to create
an instance of an object, <delete> to delete an instance of an
object, <renew> to extend the validity period of an object,
<transfer> to manage object sponsorship changes, and <update> to
change information associated with an object.
5.2.1. EPP <create> Command
This extension defines additional elements to extend the EPP <create>
command of an object mapping like [RFC5733].
The EPP <create> command provides a transform operation that allows a
client to create an instance of an object. In addition to the EPP
command elements described in an object mapping like [RFC5733], the
command MUST contain a child <addlEmail:addlEmail> element
(Section 3) for the client to set an alternate email address.
The following is an example <create> command to create a contact
object with an alternate ASCII email address:
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: <contact:create
C: xmlns:contact="urn:ietf:params:xml:ns:contact-1.0">
C: <contact:id>sh8013</contact:id>
C: <contact:postalInfo type="int">
C: <contact:name>John Doe</contact:name>
C: <contact:org>Example Inc.</contact:org>
C: <contact:addr>
C: <contact:street>123 Example Dr.</contact:street>
C: <contact:street>Suite 100</contact:street>
C: <contact:city>Dulles</contact:city>
C: <contact:sp>VA</contact:sp>
C: <contact:pc>20166-6503</contact:pc>
C: <contact:cc>US</contact:cc>
C: </contact:addr>
C: </contact:postalInfo>
C: <contact:voice x="1234">+1.7035555555</contact:voice>
C: <contact:fax>+1.7035555556</contact:fax>
C: <contact:email>jdoe@example.com</contact:email>
C: <contact:authInfo>
C: <contact:pw>2fooBAR</contact:pw>
C: </contact:authInfo>
C: <contact:disclose flag="0">
C: <contact:voice/>
C: <contact:email/>
C: </contact:disclose>
C: </contact:create>
C: </create>
C: <extension>
C: <addlEmail:addlEmail
C: xmlns:addlEmail="urn:ietf:params:xml:ns:epp:addlEmail-1.0">
C: <addlEmail:email>jdoe-alt@example.net</addlEmail:email>
C: </addlEmail:addlEmail>
C: </extension>
C: <clTRID>ABC-12345</clTRID>
C: </command>
C:</epp>
Figure 4: Example <create> command Command to create Create a contact object Contact Object
with an alternate Alternate ASCII email address Email Address
The following is an example <create> command to create a contact
object with a primary SMTPUTF8 email address:
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: <contact:create
C: xmlns:contact="urn:ietf:params:xml:ns:contact-1.0">
C: <contact:id>sh8013</contact:id>
C: <contact:postalInfo type="int">
C: <contact:name>John Doe</contact:name>
C: <contact:org>Example Inc.</contact:org>
C: <contact:addr>
C: <contact:street>123 Example Dr.</contact:street>
C: <contact:street>Suite 100</contact:street>
C: <contact:city>Dulles</contact:city>
C: <contact:sp>VA</contact:sp>
C: <contact:pc>20166-6503</contact:pc>
C: <contact:cc>US</contact:cc>
C: </contact:addr>
C: </contact:postalInfo>
C: <contact:voice x="1234">+1.7035555555</contact:voice>
C: <contact:fax>+1.7035555556</contact:fax>
C: <contact:email>jdoe@example.com</contact:email>
C: <contact:authInfo>
C: <contact:pw>2fooBAR</contact:pw>
C: </contact:authInfo>
C: <contact:disclose flag="0">
C: <contact:voice/>
C: <contact:email/>
C: </contact:disclose>
C: </contact:create>
C: </create>
C: <extension>
C: <addlEmail:addlEmail
C: xmlns:addlEmail="urn:ietf:params:xml:ns:epp:addlEmail-1.0">
C: <addlEmail:email
primary="true">麥克風@example.com</addlEmail:email>
C: </addlEmail:addlEmail>
C: </extension>
C: <clTRID>ABC-12345</clTRID>
C: </command>
C:</epp>
Figure 5: Example <create> command Command to create Create a contact object Contact Object
with a primary Primary SMTPUTF8 email address Email Address
This extension does not add any elements to the EPP <create> response
described in [RFC5730].
5.2.2. EPP <delete> Command
This extension does not add any elements to the EPP <delete> command
or <delete> response described in [RFC5730].
5.2.3. EPP <renew> Command
This extension does not add any elements to the EPP <renew> command
or <renew> response described in [RFC5730].
5.2.4. EPP <transfer> Command
This extension does not add any elements to the EPP <transfer>
command or <transfer> response described in [RFC5730].
5.2.5. EPP <update> Command
This extension defines additional elements to extend the EPP <update>
command of an object mapping like [RFC5733].
The EPP <update> command provides a transform operation that allows a
client to update an instance of an object. In addition to the EPP
command elements described in an object mapping like [RFC5733], the
command MUST contain a child <addlEmail:addlEmail> element
(Section 3) for the client to set or unset an alternate email
address. If the alternate email address cannot be applied to the
object, the server MUST return an EPP error result code of 2201.
The following is an example <update> command to set a contact object
with an alternate ASCII email address:
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: <contact:update
C: xmlns:contact="urn:ietf:params:xml:ns:contact-1.0">
C: <contact:id>sh8013</contact:id>
C: </contact:update>
C: </update>
C: <extension>
C: <addlEmail:addlEmail
C: xmlns:addlEmail="urn:ietf:params:xml:ns:epp:addlEmail-1.0">
C: <addlEmail:email>jdoe-alt@example.net</addlEmail:email>
C: </addlEmail:addlEmail>
C: </extension>
C: <clTRID>ABC-12345</clTRID>
C: </command>
C:</epp>
Figure 6: Example <update> command Command to set Set a contact object Contact Object with
an alternate Alternate ASCII email address Email Address
The following is an example <update> command to set a contact object
with an alternate SMTPUTF8 email address:
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: <contact:update
C: xmlns:contact="urn:ietf:params:xml:ns:contact-1.0">
C: <contact:id>sh8013</contact:id>
C: </contact:update>
C: </update>
C: <extension>
C: <addlEmail:addlEmail
C: xmlns:addlEmail="urn:ietf:params:xml:ns:epp:addlEmail-1.0">
C: <addlEmail:email>麥克風@example.com</addlEmail:email>
C: </addlEmail:addlEmail>
C: </extension>
C: <clTRID>ABC-12345</clTRID>
C: </command>
C:</epp>
Figure 7: Example <update> command Command to set Set a contact object Contact Object with
an alternate Alternate SMTPUTF8 email address Email Address
The following is an example <update> command to unset a contact
object alternate email address:
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: <contact:update
C: xmlns:contact="urn:ietf:params:xml:ns:contact-1.0">
C: <contact:id>sh8013</contact:id>
C: </contact:update>
C: </update>
C: <extension>
C: <addlEmail:addlEmail
C: xmlns:addlEmail="urn:ietf:params:xml:ns:epp:addlEmail-1.0">
C: <addlEmail:email/>
C: </addlEmail:addlEmail>
C: </extension>
C: <clTRID>ABC-12345</clTRID>
C: </command>
C:</epp>
Figure 8: Example <update> command Command to unset Unset a contact object
alternate email address Contact Object
Alternate Email Address
This extension does not add any elements to the EPP <update> response
described in [RFC5730].
6. Formal Syntax
The EPP Additional Email Address Extension schema is presented here.
The formal syntax shown here is a complete XML Schema
([W3C.REC-xmlschema-1-20041028], [W3C.REC-xmlschema-2-20041028])
[W3C.REC-xmlschema-1-20041028] [W3C.REC-xmlschema-2-20041028]
representation of the object mapping suitable for automated
validation of EPP XML instances. The <CODE BEGINS> and <CODE ENDS>
tags are not part of the XML Schema; they are used to note the
beginning and ending of the XML Schema for URI registration purposes.
6.1. EPP Additional Email Address Extension Schema
<CODE BEGINS>
<?xml version="1.0" encoding="UTF-8"?>
<schema xmlns="http://www.w3.org/2001/XMLSchema"
xmlns:addlEmail="urn:ietf:params:xml:ns:epp:addlEmail-1.0"
targetNamespace="urn:ietf:params:xml:ns:epp:addlEmail-1.0"
elementFormDefault="qualified">
<annotation>
<documentation>Extensible Provisioning Protocol v1.0
additional email address schema.</documentation>
</annotation>
<!-- Create, Update, and Info Response extension element -->
<element name="addlEmail" type="addlEmail:addlEmailType" />
<!--
Single email element that can be empty
-->
<complexType name="addlEmailType">
<sequence>
<element name="email" type="addlEmail:emailType"/>
</sequence>
</complexType>
<complexType name="emailType">
<simpleContent>
<extension base="token">
<attribute name="primary" type="boolean" default="false"/>
</extension>
</simpleContent>
</complexType>
<!--
End of schema.
-->
</schema>
<CODE ENDS>
7. IANA Considerations
7.1. XML Namespace
This document uses URNs to describe XML namespaces conforming to a
registry mechanism described in RFC 3688 [RFC3688]. The following URI assignment should be
assignments have been made by IANA:
Registration request for the addlEmail namespace:
URI: urn:ietf:params:xml:ns:epp:addlEmail-1.0
Registrant Contact: IESG
XML: None. Namespace URIs do not represent an XML specification.
Registration request for the addlEmail XML Schema:
URI: urn:ietf:params:xml:schema:epp:addlEmail-1.0
Registrant Contact: IESG
XML: See the "Formal Syntax" section Section 6 of this document.
7.2. EPP Extension Registry
The EPP extension described in this document should be have been registered by
IANA in the "Extensions for the Extensible Provisioning Protocol
(EPP)" registry described in RFC 7451 [RFC7451]. The details of the
registration are as follows:
Name of Extension: "Additional Additional Email Address Extension for the
Extensible Provisioning Protocol (EPP)" (EPP)
Document status: Status: Standards Track
Reference: (This specification) RFC 9873
Registrant Name and Email Address: IESG, <iesg@ietf.org>
Top-Level Domains(TLDs):
TLDs: Any
IPR Disclosure: None
Status: Active
Notes: None
8. Security Considerations
As is noted in Section Sections 10.1 and Section 13 of [RFC6530], unconstrained Unicode
in email addresses can introduce a class of security threats that do
not exist with all-ASCII email addresses. As EPP exists in
ecosystems where email addresses passed in EPP are displayed in RDAP the
Registration Data Access Protocol (RDAP) and other services, and
copy-and-paste of these email addresses is common for businesses
transferring domains via EPP, there should be safeguards against
these threats. Therefore, use of the SMTPUTF8 email addresses as
described in this document SHOULD be done with policies that disallow
the use of unconstrained Unicode. The domain-part of these SMTPUTF8
email addresses SHOULD conform to IDNA2008. The local-part of these
SMTPUTF8 email addresses SHOULD be restricted to Unicode that does
not introduce the threats noted in [RFC6530]. One such possible
solution would be to disallow characters outside of Unicode Annex 31
[Unicode-UAX31].
As an email address is often a primary end user contact, and an invalid
email address may put communication with the end user at risk when
such contact is necessary. In case of an invalid domain name in the
email address address, a malicious actor can register a valid domain name
with a similar U-label (homograph attack) and assume control over the
domain name associated with the contact using social engineering
techniques. To reduce the risk of the use of invalid domain names in
email addresses, registries SHOULD validate the domain name syntax in
the provided email addresses and validate whether the domain name
consists of the code points allowed by IDNA "IDNA Rules and Derived
Property Values Values" (https://www.iana.org/assignments/idna-tables).
Note that the syntax for internationalized email localparts is very
liberal. Domains are normalized during MX lookup, while localparts
are unconstrained. Implementers may wish to test that their database
is able to store difficult localparts such as U+0061 U+0300 U+00E0.
For more on normalization and these three code points, see [RFC5198] [RFC5198],
Section 3.
9. Privacy Considerations
The content of <addlEmail:email> elements can be processed by EPP
clients and servers in the same way that <contact:email> elements are
processed, including publication in directory services such as RDAP
[STD95]. Many data protection regulations recognize email addresses
as personal data, so any policies governing the collection,
transmission, and processing of contact information by EPP clients
and servers should apply equally to <addlEmail:email> elements.
10. References
10.1. Normative References
[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>.
[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
DOI 10.17487/RFC3688, January 2004,
<https://www.rfc-editor.org/info/rfc3688>.
[RFC5321] Klensin, J., "Simple Mail Transfer Protocol", RFC 5321,
DOI 10.17487/RFC5321, October 2008,
<https://www.rfc-editor.org/info/rfc5321>.
[RFC5322] Resnick, P., Ed., "Internet Message Format", RFC 5322,
DOI 10.17487/RFC5322, October 2008,
<https://www.rfc-editor.org/info/rfc5322>.
[RFC5730] Hollenbeck, S., "Extensible Provisioning Protocol (EPP)",
STD 69, RFC 5730, DOI 10.17487/RFC5730, August 2009,
<https://www.rfc-editor.org/info/rfc5730>.
[RFC5733] Hollenbeck, S., "Extensible Provisioning Protocol (EPP)
Contact Mapping", STD 69, RFC 5733, DOI 10.17487/RFC5733,
August 2009, <https://www.rfc-editor.org/info/rfc5733>.
[RFC5890] Klensin, J., "Internationalized Domain Names for
Applications (IDNA): Definitions and Document Framework",
RFC 5890, DOI 10.17487/RFC5890, August 2010,
<https://www.rfc-editor.org/info/rfc5890>.
[RFC6530] Klensin, J. and Y. Ko, "Overview and Framework for
Internationalized Email", RFC 6530, DOI 10.17487/RFC6530,
February 2012, <https://www.rfc-editor.org/info/rfc6530>.
[RFC6531] Yao, J. and W. Mao, "SMTP Extension for Internationalized
Email", RFC 6531, DOI 10.17487/RFC6531, February 2012,
<https://www.rfc-editor.org/info/rfc6531>.
[RFC6532] Yang, A., Steele, S., and N. Freed, "Internationalized
Email Headers", RFC 6532, DOI 10.17487/RFC6532, February
2012, <https://www.rfc-editor.org/info/rfc6532>.
[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>.
[W3C.REC-xmlschema-1-20041028]
Beech, D., Ed., Thompson, H., Ed., Maloney, M., Ed., and
N. Mendelsohn, Ed., "XML Schema Part 1: Structures Second
Edition", W3C REC REC-xmlschema-1-20041028, W3C REC-
xmlschema-1-20041028, Recommendation, 28 October 2004,
<https://www.w3.org/TR/2004/REC-xmlschema-1-20041028/>.
[W3C.REC-xmlschema-2-20041028]
Malhotra, A., Ed. and P. V. Biron, Ed., "XML Schema Part
2: Datatypes Second Edition", W3C REC REC-xmlschema-
2-20041028, W3C REC-xmlschema-2-20041028, Recommendation, 28
October 2004,
<https://www.w3.org/TR/2004/REC-xmlschema-2-20041028/>.
<https://www.w3.org/TR/2004/REC-xmlschema-2-20041028>.
10.2. Informative References
[RFC5198] Klensin, J. and M. Padlipsky, "Unicode Format for Network
Interchange", RFC 5198, DOI 10.17487/RFC5198, March 2008,
<https://www.rfc-editor.org/info/rfc5198>.
[RFC7451] Hollenbeck, S., "Extension Registry for the Extensible
Provisioning Protocol", RFC 7451, DOI 10.17487/RFC7451,
February 2015, <https://www.rfc-editor.org/info/rfc7451>.
[STD95] Internet Standard 95,
<https://www.rfc-editor.org/info/std95>.
At the time of writing, this STD comprises the following:
Newton, A., Ellacott, B., and N. Kong, "HTTP Usage in the
Registration Data Access Protocol (RDAP)", STD 95,
RFC 7480, DOI 10.17487/RFC7480, March 2015,
<https://www.rfc-editor.org/info/rfc7480>.
Hollenbeck, S. and N. Kong, "Security Services for the
Registration Data Access Protocol (RDAP)", STD 95,
RFC 7481, DOI 10.17487/RFC7481, March 2015,
<https://www.rfc-editor.org/info/rfc7481>.
Hollenbeck, S. and A. Newton, "Registration Data Access
Protocol (RDAP) Query Format", STD 95, RFC 9082,
DOI 10.17487/RFC9082, June 2021,
<https://www.rfc-editor.org/info/rfc9082>.
Hollenbeck, S. and A. Newton, "JSON Responses for the
Registration Data Access Protocol (RDAP)", STD 95,
RFC 9083, DOI 10.17487/RFC9083, June 2021,
<https://www.rfc-editor.org/info/rfc9083>.
Blanchet, M., "Finding the Authoritative Registration Data
Access Protocol (RDAP) Service", STD 95, RFC 9224,
DOI 10.17487/RFC9224, March 2022,
<https://www.rfc-editor.org/info/rfc9224>.
[Unicode-UAX31]
The Unicode Consortium,
Davis, M., Ed. and R. Leroy, Ed., "Unicode Standard Annex #31:
Unicode Identifiers and
Syntax", Version 16.0.0, Unicode Standard Annex #31,
September 2024,
<https://unicode.org/reports/tr31/>.
<https://www.unicode.org/reports/tr31/tr31-41.html>.
Latest version available at
<https://www.unicode.org/reports/tr31/>.
Acknowledgments
The authors would like to thank Alexander Mayrhofer, Chris Lonvick,
Gustavo Lozano, Jody Kolker, John C C. Klensin, John Levine, Klaus
Malorny, Marc Blanchet, Marco Schrieck, Mario Loffredo, Murray
S. Kucherawy, Patrick Mevzek, Pete Resnick, Takahiro Nemoto, Taras
Heichenko, Arnt Gulbrandsen, Thomas Corte, Gavin Brown, and Andrew
Newton for their careful review and valuable comments.
Authors' Addresses
Dmitry Belyavskiy
Karpatska 241/3
62500 Brno
Czech Republic
Phone: +420 603 261 036
Email: beldmit@gmail.com
James Gould
VeriSign, Inc.
12061 Bluemont Way
Reston, VA 20190
United States of America
Email: jgould@verisign.com
URI: http://www.verisigninc.com https://www.verisigninc.com
Scott Hollenbeck
Verisign Labs
12061 Bluemont Way
Reston, VA 20190
United States of America
Email: shollenbeck@verisign.com
URI: https://www.verisignlabs.com/