XMPP Enumservice: IANA Registration for Enumservice 'XMPP'
Registers the XMPP Enumservice so a phone number's DNS entry can point to an xmpp address.
Mayrhofer, A., "IANA Registration for Enumservice 'XMPP'", RFC 4979, DOI 10.17487/RFC4979, August 2007, <https://www.rfc-editor.org/info/rfc4979>.
@misc{rfc4979,
series = {Request for Comments},
number = 4979,
howpublished = {RFC 4979},
publisher = {RFC Editor},
doi = {10.17487/RFC4979},
url = {https://www.rfc-editor.org/info/rfc4979},
author = {A. Mayrhofer},
title = {{IANA Registration for Enumservice 'XMPP'}},
pagetotal = 7,
year = 2007,
month = aug,
} RFC text
Contents
Network Working Group A. Mayrhofer
Request for Comments: 4979 enum.at
Category: Standards Track August 2007
IANA Registration for Enumservice 'XMPP'
Status of This Memo
This document specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.
Copyright Notice
Copyright (C) The IETF Trust (2007).
Abstract
This document requests IANA registration of an Enumservice for XMPP,
the Extensible Messaging and Presence Protocol. This Enumservice
specifically allows the use of 'xmpp' Uniform Resource Identifiers
(URIs) in the context of E.164 Number Mapping (ENUM).
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . 2
3. Enumservice Registration - XMPP . . . . . . . . . . . . . . . . 2
4. XMPP IRI/URI Considerations for ENUM . . . . . . . . . . . . . 3
4.1. Authority Component . . . . . . . . . . . . . . . . . . . . 3
4.2. IRI-to-URI mapping . . . . . . . . . . . . . . . . . . . . 3
5. Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
6. Security and Privacy Considerations . . . . . . . . . . . . . . 4
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 4
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 4
9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 5
9.1. Normative References . . . . . . . . . . . . . . . . . . . 5
9.2. Informative References . . . . . . . . . . . . . . . . . . 5
1. Introduction
E.164 Number Mapping (ENUM) [1] uses the Domain Name System (DNS) [6]
to refer from E.164 numbers [7] to Uniform Resource Identifiers
(URIs) [3]. Specific services to be used with ENUM must be
registered with IANA. Section 3 of RFC 3761 describes the process of
such an Enumservice registration.
The Extensible Messaging and Presence Protocol (XMPP) [9] provides
means for streaming Extensible Markup Language (XML) [8] elements
between endpoints in close to real time. The XMPP framework is
mainly used to provide instant messaging, presence, and streaming
media services.
RFC 4622 [5] registers a Uniform Resource Identifier (URI) scheme for
identifying an XMPP entity as a URI or as an Internationalized
Resource Identifier (IRI) [4]. The Enumservice specified in this
document allows the provisioning of such "xmpp" URIs (and the URI
representations of "xmpp" IRIs) in ENUM.
2. Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [2].
3. Enumservice Registration - XMPP
The following template contains information required for the IANA
registrations of the 'XMPP' Enumservice, according to Section 3 of
RFC 3761:
Enumservice Name: "XMPP"
Enumservice Type: "xmpp"
Enumservice Subtype: n/a
URI Schemes: "xmpp"
Functional Specification:
This Enumservice indicates that the resource identified is an XMPP
entity.
Security Considerations: see Section 6
Intended Usage: COMMON
Author: Alexander Mayrhofer <alexander.mayrhofer@enum.at>
4. XMPP IRI/URI Considerations for ENUM
4.1. Authority Component
XMPP IRIs/URIs optionally contain an "Authority Component" (see
Section 2.3 of RFC 4622). The presence of such an Authority
Component in an IRI/URI signals the processing application to
authenticate as the user indicated in the URI/IRI rather than using
the preconfigured identity.
In the context of this Enumservice, arbitrary clients may discover
and use the XMPP URIs/IRIs associated to an E.164 number. Hence, in
most cases, those clients will not be able to authenticate as
requested in the Authority Component.
Therefore, URIs/IRIs that result from processing an XMPP Enumservice
record SHOULD NOT contain an Authority Component.
4.2. IRI-to-URI mapping
While XMPP supports IRIs as well as 'plain' URIs, ENUM itself
supports only the use of URIs for Enumservices.
Therefore, XMPP IRIs MUST be mapped to URIs for use in an XMPP
Enumservice record. The mapping MUST follow the procedures outlined
in Section 3.1 of RFC 3987.
5. Example
An example ENUM entry referencing to a XMPP URI could look like:
$ORIGIN 6.9.4.0.6.9.4.5.1.1.4.4.e164.arpa.
@ IN NAPTR ( 100 10 "u"
"E2U+xmpp"
"!^.*$!xmpp:some-user@example.com!" .
)
6. Security and Privacy Considerations
General security considerations of the protocols on which this
Enumservice registration is based are addressed in Sections 3.1.3 and
6 of RFC 3761 (ENUM) and Section 14 of RFC 3920 (XMPP).
Since ENUM uses DNS -- a publicly available database -- any
information contained in records provisioned in ENUM domains must be
considered public as well. Even after revoking the DNS entry and
removing the referred resource, copies of the information could still
be available.
Information published in ENUM records could reveal associations
between E.164 numbers and their owners -- especially if IRIs/URIs
contain personal identifiers or domain names for which ownership
information can be obtained easily.
However, it is important to note that the ENUM record itself does not
need to contain any personal information. It just points to a
location where access to personal information could be granted.
ENUM records pointing to third-party resources can easily be
provisioned on purpose by the ENUM domain owner -- so any assumption
about the association between a number and an entity could therefore
be completely bogus unless some kind of identity verification is in
place. This verification is out of scope for this memo.
7. IANA Considerations
This memo requests IANA to add a new "XMPP" Enumservice to the
'Enumservice Registrations' registry, according to the definitions in
this document and RFC 3761 [1].
The required template is contained in Section 3.
8. Acknowledgements
Some text from RFC 4622 was used in the Introduction of this
document. Charles Clancy, Miguel Garcia, Andrew Newton, Jon
Peterson, and Peter Saint-Andre provided extensive reviews and
valuable feedback.
9. References
9.1. Normative References
[1] Faltstrom, P. and M. Mealling, "The E.164 to Uniform Resource
Identifiers (URI) Dynamic Delegation Discovery System (DDDS)
Application (ENUM)", RFC 3761, April 2004.
[2] Bradner, S., "Key words for use in RFCs to Indicate Requirement
Levels", BCP 14, RFC 2119, March 1997.
[3] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
Resource Identifier (URI): Generic Syntax", STD 66, RFC 3986,
January 2005.
[4] Duerst, M. and M. Suignard, "Internationalized Resource
Identifiers (IRIs)", RFC 3987, January 2005.
[5] Saint-Andre, P., "Internationalized Resource Identifiers (IRIs)
and Uniform Resource Identifiers (URIs) for the Extensible
Messaging and Presence Protocol (XMPP)", RFC 4622, July 2006.
9.2. Informative References
[6] Mockapetris, P., "Domain names - implementation and
specification", STD 13, RFC 1035, November 1987.
[7] ITU-T, "The international public telecommunication numbering
plan", Recommendation E.164 (02/05), Feb. 2005.
[8] Maler, E., Paoli, J., Bray, T., Yergeau, F., and C. Sperberg-
McQueen, "Extensible Markup Language (XML) 1.0 (Third Edition)",
World Wide Web Consortium FirstEdition REC-xml-20040204,
February 2004, <http://www.w3.org/TR/2004/REC-xml-20040204>.
[9] Saint-Andre, P., Ed., "Extensible Messaging and Presence
Protocol (XMPP): Core", RFC 3920, October 2004.
Author's Address
Alexander Mayrhofer
enum.at GmbH
Karlsplatz 1/2/9
Wien A-1010
Austria
Phone: +43 1 5056416 34
EMail: alexander.mayrhofer@enum.at
URI: http://www.enum.at/
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AI ELI5
On this page
§1Introduction
E.164 Number Mapping (ENUM) uses the Domain Name System to refer from E.164 telephone numbers to URIs. Services used with ENUM must be registered with IANA, following Section 3 of RFC 3761.
The Extensible Messaging and Presence Protocol (XMPP) streams XML elements between endpoints in close to real time. It is mainly used for instant messaging, presence and streaming media services.
RFC 4622 registers a URI scheme for identifying an XMPP entity, as a URI or an Internationalized Resource Identifier (IRI). This Enumservice allows such xmpp URIs, and the URI forms of xmpp IRIs, to be provisioned in ENUM.
Phone numbers can be looked up to find other addresses. This RFC adds chat addresses to the list of things you can find.
§3The Enumservice Registration
The registration template gives the Enumservice name XMPP, the type xmpp and no subtype. The only URI scheme is xmpp, and the intended usage is COMMON.
The functional specification is short: the resource identified is an XMPP entity.
The RFC fills in a form that names the new service and says its addresses start with xmpp.
§4XMPP IRI and URI Rules for ENUM
An XMPP IRI or URI may contain an Authority Component (Section 2.3 of RFC 4622). Its presence tells the application to authenticate as the user named in the URI instead of using its preconfigured identity. In ENUM, arbitrary clients may discover and use the URIs, so in most cases they cannot authenticate as requested. URIs that result from an XMPP Enumservice record therefore SHOULD NOT contain an Authority Component.
XMPP supports IRIs as well as plain URIs, but ENUM supports only URIs for Enumservices. XMPP IRIs MUST therefore be mapped to URIs for use in an XMPP Enumservice record, following Section 3.1 of RFC 3987.
Some chat addresses say 'log in as this person'. Strangers looking up a phone number cannot do that, so the RFC says to leave that part out.
§5Example Record
The RFC shows a NAPTR record under e164.arpa. Its service field is E2U+xmpp, and its rewrite rule yields the URI xmpp:some-user@example.com.
One line in the internet's phone book says: for this phone number, the chat address is some-user at example.com.
$ORIGIN 6.9.4.0.6.9.4.5.1.1.4.4.e164.arpa.
@ IN NAPTR ( 100 10 "u"
"E2U+xmpp"
"!^.*$!xmpp:some-user@example.com!" .
)§6Security and Privacy
General security considerations come from the protocols underneath: Sections 3.1.3 and 6 of RFC 3761 for ENUM and Section 14 of RFC 3920 for XMPP.
DNS is a public database, so anything in an ENUM record must be considered public, and copies could remain after the record is revoked. Records can reveal associations between numbers and their owners, especially if the URIs contain personal identifiers or easily traced domain names. The record itself need not contain personal information, since it just points to a location.
Records pointing to third-party resources can be provisioned on purpose by the domain owner, so a claimed association between a number and an entity could be bogus without identity verification, which is out of scope.
The phone book is public, so anyone can read it. Someone could also write a wrong chat address next to your number, so do not trust it blindly.
§7IANA Considerations
The memo asks IANA to add a new XMPP Enumservice to the 'Enumservice Registrations' registry, according to the definitions in this document and RFC 3761. The required template is in Section 3.
The RFC asks the keeper of internet lists to add one new entry using the form in Section 3.