Internet DRAFT - draft-belyavskiy-epp-eai
draft-belyavskiy-epp-eai
Network Working Group D. Belyavskiy
Internet-Draft
Intended status: Standards Track J. Gould
Expires: 26 August 2021 VeriSign, Inc.
22 February 2021
Use of Internationalized Email Addresses in EPP protocol
draft-belyavskiy-epp-eai-04
Abstract
This document describes an EPP extension that permits usage of
Internationalized Email Addresses in the EPP protocol and specifies
the terms when it can be used by EPP clients and servers. The
Extensible Provisioning Protocol (EPP), being developed before
appearing the standards for Internationalized Email Addresses (EAI),
does not support such email addresses.
TO BE REMOVED on turning to RFC: The document is edited in the
dedicated github repo (https://github.com/beldmit/eppeai). Please
send your submissions via GitHub.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
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This Internet-Draft will expire on 26 August 2021.
Copyright Notice
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.
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Please review these documents carefully, as they describe your rights
and restrictions with respect to this document. Code Components
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Conventions Used in This Document . . . . . . . . . . . . 3
2. Migrating to Newer Versions of This Extension . . . . . . . . 3
3. Email Address Specification . . . . . . . . . . . . . . . . . 3
4. Functional Extension . . . . . . . . . . . . . . . . . . . . 4
5. Internationalized Email Addresses (EAI) Functional
Extension . . . . . . . . . . . . . . . . . . . . . . . . 4
5.1. Scope of Functional Extension . . . . . . . . . . . . . . 4
5.2. Signaling Client and Server Support . . . . . . . . . . . 5
5.3. Functional Extension Behavior . . . . . . . . . . . . . . 5
5.3.1. EAI Functional Extension Negotiated . . . . . . . . . 5
5.3.2. EAI Functional Extension Not Negotiated . . . . . . . 6
6. Security Considerations . . . . . . . . . . . . . . . . . . . 7
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7
7.1. XML Namespace . . . . . . . . . . . . . . . . . . . . . . 7
7.2. EPP Extension Registry . . . . . . . . . . . . . . . . . 7
8. Implementation Considerations . . . . . . . . . . . . . . . . 8
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 8
9.1. Normative References . . . . . . . . . . . . . . . . . . 8
9.2. Informative References . . . . . . . . . . . . . . . . . 9
Appendix A. Change History . . . . . . . . . . . . . . . . . . . 9
A.1. Change from 00 to 01 . . . . . . . . . . . . . . . . . . 9
A.2. Change from 01 to 02 . . . . . . . . . . . . . . . . . . 9
A.3. Change from 02 to 03 . . . . . . . . . . . . . . . . . . 10
A.4. Change from 03 to 04 . . . . . . . . . . . . . . . . . . 10
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 10
1. Introduction
[RFC6530] introduced the framework for Internationalized Email
Addresses. To make such addresses more widely accepted, the changes
to various protocols need to be introduced.
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This document describes an Extensible Provisioning Protocol (EPP)
extension that permits usage of Internationalized Email Addresses in
the EPP protocol and specifies the terms when it can be used by EPP
clients and servers. A new form of EPP extension, referred to as a
Functional Extension, is defined and used to apply the rules for the
handling of email address elements in all of the [RFC5730] extensions
negotiated in the EPP session, which include the object and command-
responses extensions. The described mechanism can be applied to any
object or command-response extension that uses an email address.
The Extensible Provisioning Protocol (EPP) specified in [RFC5730] is
a base document for object management operations and an extensible
framework that maps protocol operations to objects. The specifics of
various objects managed via EPP is described in separate documents.
This document is only referring to an email address as a property of
a managed object, such as the <contact:email> element in the EPP
contact mapping [RFC5733] or the <org:email> element in the EPP
organization mapping [RFC8543], and command-response extensions
applied to a managed object.
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.
2. Migrating to Newer Versions of This Extension
Servers that implement this extension SHOULD provide a way for
clients to progressively update their implementations when a new
version of the extension is deployed. A newer version of the
extension is expected to use an XML namespace with a higher version
number than the prior versions.
3. Email Address Specification
Support of non-ASCII email address syntax is defined in RFC 6530
[RFC6530]. This mapping does not prescribe minimum or maximum
lengths for character strings used to represent email addresses. The
exact syntax of such addresses is described in Section 3.3 of
[RFC6531]. The validation rules introduced in RFC 6531 are
considered to be followed.
The definition of email address in the EPP RFCs, including
Section 2.6 of [RFC5733] and Section 4.1.2, 4.2.1, and 4.2.5 of
[RFC8543], references [RFC5322] for the email address syntax. The
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XML schema definition in Section 4 of [RFC5733] and Section 5 of
[RFC8543] defines the "email" element using the type
"eppcom:minTokenType", which is defined in Section 4.2 of [RFC5730]
as an XML schema "token" type with minimal length of one. The XML
schema "token" type will fully support the use of EAI addresses, so
the primary application of the EAI extension is to apply the use of
[RFC6531] instead of [RFC5322] for the email address syntax. Other
EPP extensions may follow the formal syntax definition using the XML
schema type "eppcom:minTokenType" and the [RFC5322] format
specification, where this extension applies to all EPP extensions
with the same or similar definitions.
The email address format is formally defined in Section 3.4.1 of
[RFC5322], which only consists of printable US-ASCII characters for
both the local-part and the domain ABNF rules. In [RFC6531], the
extends the Mailbox, Local-part and Domain ABNF rules in [RFC5321] to
support "UTF8-non-ascii", defined in Section 3.1 of [RFC6532], for
the local-part and U-label, defined in Section 2.3.2.1 of [RFC5890],
for the domain. By applying the syntax rules of [RFC5322], the EPP
extensions will change from supporting only ASCII characters to
supporting Internationailzed characters in the email address local-
part and domain-part.
4. Functional Extension
[RFC5730] defines three types of extensions at the protocol, object,
and command-response level, which impact the structure of the EPP
messages. A Functional Extension applies a functional capability to
an existing set of EPP extensions and properties. The scope of the
applicable EPP extensions and applicable extension properties are
defined in the Functional Extension along with the requirements for
the servers and clients that support it. The Functional Extension
needs to cover the expected behavior of the supporting client or
server when interfacing with an unsupporting client or server.
Negotiating support for a Functional Extension is handled using the
EPP Greeting and EPP Login services.
5. Internationalized Email Addresses (EAI) Functional Extension
5.1. Scope of Functional Extension
The functional extension applies to all object extensions and
command-response extensions negotiated in the EPP session that
include email address properties. Examples include the
<contact:email> element in the EPP contact mapping [RFC5733] or the
<org:email> element in the EPP organization mapping [RFC8543]. All
registry zones (e.g., top-level domains) authorized for the client in
the EPP session apply. There is no concept of a per-client, per-
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zone, per-extension, or per-field setting that is used to indicate
support for EAI, but instead it's a global setting that applies to
the EPP session.
5.2. Signaling Client and Server Support
The client and the server can signal support for the functional
extension using a namespace URI in the login and greeting extension
services. The namespace URI "urn:ietf:params:xml:ns:epp:eai-0.2" is
used to signal support for the functional extension. The client
includes the namespace URI in an <svcExtension> <extURI> element of
the [RFC5730] <login> Command. The server includes the namespace URI
in an <svcExtension> <extURI> element of the [RFC5730] Greeting.
5.3. Functional Extension Behavior
5.3.1. EAI Functional Extension Negotiated
If both client and server have indicated the support of the EAI
addresses during the session establishment, it implies possibility to
process the EAI address in any message having an email property
during the established EPP session. Below are the server and client
obligations when the EAI extension has been successfuly negotiated in
the EPP session.
The server MUST satisfy the following obligations when the EAI
extension has been negotiated:
* Accept EAI compatible addresses for all email properties in the
EPP session negotiated object extensions and command-response
extensions. For example the <contact:email> element in [RFC5733]
and the <org:email> element in [RFC8543].
* Accept EAI compatible addresses for all registry zones (e.g., top-
level domains) authorized for the client in the EPP session.
* Email address validation based on EAI validation rules defined in
Section 3
* Storage of email properties that supports internationalized
characters.
* Return EAI compatible addresses for all email properties in the
EPP responses.
The server MUST satisfy the following obligations when THE EAI
extension has been negotiated:
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* Provide EAI compatible addresses for all e-mail properties in the
EPP session negotiated object extensions and command-response
extensions. For example the <contact:email> element in [RFC5733]
and the <org:email> element in [RFC8543].
* Provide EAI compatible addresses for all registry zones (e.g.,
top-level domains) authorized for the client in the EPP session.
* Accept EAI compatible addresses in the EPP responses for all email
properties in the EPP session negotiated object extensions and
command-response extensions.
5.3.2. EAI Functional Extension Not Negotiated
The lack of EAI support can cause data and functional issues, so an
EAI supporting client or server needs to handle cases where the
opposite party doesn't support EAI. Below are the server and client
obligations when the EAI extension is not negotiated due to the lack
of support by the opposite party.
The EAI supporting server MUST satisfy the following obligations when
the client does not support the EAI extension:
* When the email property is required in the EPP extension command,
the server SHOULD validate the email property by the client using
the ASCII email validation rules.
* When the email property is optional according the EPP extension
command, if the client supplies the email property the server
SHOULD validate the email property using the ASCII email
validation rules.
* When the email property is required in the EPP extension response,
the server MUST validate whether the email property is an EAI
address and if so return the predefined placeholder email TBD and
otherwise return the email property that has been set.
* When the email property is optional in the EPP extension response,
the server MUST validate whether the email property is an EAI
address and if so don't return the email property in the response
and otherwise return the email property that has been set based on
server policy.
The EAI supporting client MUST satisfy the following obligations when
the server does not support the EAI extension:
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* When the email property is required in the EPP extension command
and the email property is an EAI address with no alternative ASCII
address, the client MUST provide the predefined placeholder email
address TBD.
* When the email property is optional in the EPP extension command
and the email property is an EAI address with no alternative ASCII
address, the client SHOULD omit the email property.
6. Security Considerations
Registries SHOULD validate the domain names in the provided email
addresses. This can be done by validating all code points according
to IDNA2008 [RFC5892].
7. IANA Considerations
7.1. XML Namespace
This document uses URNs to describe XML namespaces and XML schemas
conforming to a registry mechanism described in RFC 3688 [RFC3688].
The following URI assignment should be made by IANA:
Registration request for the eai namespace:
URI: urn:ietf:params:xml:ns:epp:eai-0.2
Registrant Contact: IESG
XML: None. Namespace URIs do not represent an XML specification.
Registration request for the eai XML Schema:
URI: urn:ietf:params:xml:schema:epp:eai-0.2
Registrant Contact: IESG
XML: See the "Formal Syntax" section of this document.
7.2. EPP Extension Registry
The EPP extension described in this document should be 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:
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Name of Extension: Use of Internationalized Email Addresses
in EPP protocol
Document status: Standards Track
Reference: TBA
Registrant Name and Email Address: IESG, <iesg@ietf.org>
Top-Level Domains(TLDs): Any
IPR Disclosure: None
Status: Active
Notes: None
8. Implementation Considerations
Registries MAY apply extra limitation to the email address syntax
(e.g. the addresses can be limited to Left-to-Right scripts). These
limitations are out of scope of this document.
9. References
9.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.27487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
DOI 10.27487/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 10.27487/RFC5730, August 2009,
<https://www.rfc-editor.org/info/rfc5730>.
[RFC5733] Hollenbeck, S., "Extensible Provisioning Protocol (EPP)
Contact Mapping", STD 69, RFC 5733, DOI 10.27487/RFC5733,
August 2009, <https://www.rfc-editor.org/info/rfc5733>.
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[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 10.27487/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>.
[RFC7451] Hollenbeck, S., "Extension Registry for the Extensible
Provisioning Protocol", RFC 7451, DOI 10.27487/RFC7451,
February 2015, <https://www.rfc-editor.org/info/rfc7451>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.27487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
9.2. Informative References
[RFC5892] Faltstrom, P., Ed., "The Unicode Code Points and
Internationalized Domain Names for Applications (IDNA)",
RFC 5892, DOI 10.27487/RFC5892, August 2010,
<https://www.rfc-editor.org/info/rfc5892>.
[RFC8543] Zhou, L., Kong, N., Yao, J., Gould, J., and G. Zhou,
"Extensible Provisioning Protocol (EPP) Organization
Mapping", RFC 8543, DOI 10.27487/RFC8543, March 2019,
<https://www.rfc-editor.org/info/rfc8543>.
Appendix A. Change History
A.1. Change from 00 to 01
1. Changed from update of RFC 5733 to use the "Placeholder Text and
a New Email Element" EPP Extension approach.
A.2. Change from 01 to 02
1. Fixed the XML schema and the XML examples based on validating
them.
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2. Added James Gould as co-author.
3. Updated the language to apply to any EPP object mapping and to
use the EPP contact mapping as an example.
4. Updated the structure of document to be consistent with the other
Command-Response Extensions.
5. Replaced the use of "eppEAI" in the XML namespace and the XML
namespace prefix with "eai".
6. Changed to use a pointed XML namespace with "0.2" instead of
"1.0".
A.3. Change from 02 to 03
1. The approach has changed to use the concept of Functional EPP
Extension.
2. The examples are removed
A.4. Change from 03 to 04
1. More detailed reference to email syntax is provided
2. The shortened eai namespace reference is removed
Authors' Addresses
Dmitry Belyavskiy
8 marta st.
Moscow
127083
Russian Federation
Phone: +7 916 262 5593
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
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