Internet Engineering Task Force (IETF) S. Kille

Internet Engineering Task Force (IETF) S. Kille
Request for Comments: 8284 Isode Ltd
Category: Informational November 2017
ISSN: 2070-1721

Lightweight Directory Access Protocol (LDAP) Schema for Supporting
the Extensible Messaging and Presence Protocol (XMPP) in White Pages

Abstract

The Extensible Messaging and Presence Protocol (XMPP) identifies
users by use of Jabber IDs (JIDs). The Lightweight Directory Access
Protocol (LDAP) enables provision of a white pages service with a
schema relating to users and support for Internet protocols. This
specification defines a schema to enable XMPP JIDs to be associated
with objects in an LDAP directory so that this information can be
used with white pages applications.

Status of This Memo

This document is not an Internet Standards Track specification; it is
published for informational purposes.

This document is a product of the Internet Engineering Task Force
(IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Not all documents
approved by the IESG are a candidate for any level of Internet
Standard; see Section 2 of RFC 7841.

Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
https://www.rfc-editor.org/info/rfc8284.

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Copyright Notice

Copyright (c) 2017 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, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.

Table of Contents

1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Conventions Used in This Document . . . . . . . . . . . . . . 3
3. Schema Definition . . . . . . . . . . . . . . . . . . . . . . 3
3.1. Object Class . . . . . . . . . . . . . . . . . . . . . . 3
3.2. Attribute . . . . . . . . . . . . . . . . . . . . . . . . 3
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4
5. Security Considerations . . . . . . . . . . . . . . . . . . . 5
6. Normative References . . . . . . . . . . . . . . . . . . . . 5
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 6
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 6

1. Introduction

Extensible Messaging and Presence Protocol (XMPP) [RFC6120]
identifies users by use of Jabber IDs (JIDs). The Lightweight
Directory Access Protocol (LDAP) [RFC4510] enables provision of a
white pages service with a schema relating to users and support for
Internet protocols defined in [RFC4519]. This specification defines
a schema to enable XMPP JIDs to be associated with LDAP directory
objects so that this information can be used with white pages
applications.

The LDAP schema for storing JIDs is defined to enable JIDs to be
associated with any object stored in the directory. This is done by
associating the new JID Attribute with a new Auxiliary Object Class
called JIDObject.

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2. 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.

3. Schema Definition

This section defines the schema used to store JIDs in the directory.

3.1. Object Class

This section defines a new Auxiliary Object Class called JIDObject,
which MAY be associated with any structural Object Class. This
Object Class is used to augment entries for objects that act or may
act as an XMPP client. The JID attribute is optional in order to
enable configuring an object that is allowed to have an associated
JID but does not currently have one.

( 1.3.6.1.1.23.1 NAME 'JIDObject'
AUXILIARY
MAY jid )

3.2. Attribute

This section defines the JID attribute referenced by the JIDObject
Auxiliary Object Class. The syntax of the JID attribute MUST follow
the rules of [RFC7622]. The JID stored MUST be a bare JID (e.g., a
JID such as [email protected] representing a human user)
and not a full JID (e.g., a JID such as
[email protected]/AABBCC, which represents a specific XMPP
client used by the human user and is identified by the resource
AABBCC). Note that the LDAP directory server is not expected to
enforce this syntax. The syntax rules are for LDAP clients setting
this attribute, noting that human usage is a key target.
Applications using this attribute should format that string in a
manner appropriate to the application, and XMPP applications SHOULD
apply [RFC7622] to the attribute. The directory service doesn't
enforce the JID syntax, and values are compared according to the
matching rules specified in the attribute definition.

Note that for the convenience of users and administrators as well as
implementers, the Directory String syntax and the caseIgnoreMatch
matching rule are chosen to allow entry and matching of values
according to common rules used within the directory. As this syntax
and matching rule differ from [RFC7622], false positives and false

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negatives can possibly occur. This is not anticipated to cause
operational issues (based on implementation experience with similar
syntax/matching rule mismatches).

( 1.3.6.1.1.23.2 NAME 'jid'
EQUALITY caseIgnoreMatch
SUBSTR caseIgnoreSubstringsMatch
SYNTAX 1.3.6.1.4.1.1466.115.121.1.15 )

1.3.6.1.4.1.1466.115.121.1.15 refers to the Directory String syntax
defined in [RFC4517].

4. IANA Considerations

The following registrations have been made in the "Lightweight
Directory Access Protocol (LDAP) Parameters" registry
<https://www.iana.org/assignments/ldap-parameters> in line with
BCP 64 [RFC4520].

Object Identifier Registration

An object identifier has been assigned to support the registrations
necessary for this specification by an entry in the Internet
Directory Numbers (iso.org.dod.internet.directory [1.3.6.1.1.])
registry:

Decimal: 23
Name: xmpp
Description: LDAP schema for XMPP

Two object identifiers have been assigned:

'JIDObject' Descriptor Registration

Name: JIDObject
Type: O
OID: 1.3.6.1.1.23.1

'jid' Descriptor Registration

Name: jid
Type: A
OID: 1.3.6.1.1.23.2

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5. Security Considerations

XMPP JIDs are often personal identifiers enabling electronic
communication and have similar considerations to email addresses.
This schema enables publishing of this information in LDAP
directories, which may be corporate or public services. Care should
be taken to only publish JID information that is acceptable both to
be linked to the LDAP object and to be made accessible to all LDAP
users. The general LDAP security considerations specified in
[RFC4510] also apply.

6. 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>.

[RFC4510] Zeilenga, K., Ed., "Lightweight Directory Access Protocol
(LDAP): Technical Specification Road Map", RFC 4510,
DOI 10.17487/RFC4510, June 2006,
<https://www.rfc-editor.org/info/rfc4510>.

[RFC4517] Legg, S., Ed., "Lightweight Directory Access Protocol
(LDAP): Syntaxes and Matching Rules", RFC 4517,
DOI 10.17487/RFC4517, June 2006,
<https://www.rfc-editor.org/info/rfc4517>.

[RFC4519] Sciberras, A., Ed., "Lightweight Directory Access Protocol
(LDAP): Schema for User Applications", RFC 4519,
DOI 10.17487/RFC4519, June 2006,
<https://www.rfc-editor.org/info/rfc4519>.

[RFC4520] Zeilenga, K., "Internet Assigned Numbers Authority (IANA)
Considerations for the Lightweight Directory Access
Protocol (LDAP)", BCP 64, RFC 4520, DOI 10.17487/RFC4520,
June 2006, <https://www.rfc-editor.org/info/rfc4520>.

[RFC6120] Saint-Andre, P., "Extensible Messaging and Presence
Protocol (XMPP): Core", RFC 6120, DOI 10.17487/RFC6120,
March 2011, <https://www.rfc-editor.org/info/rfc6120>.

[RFC7622] Saint-Andre, P., "Extensible Messaging and Presence
Protocol (XMPP): Address Format", RFC 7622,
DOI 10.17487/RFC7622, September 2015,
<https://www.rfc-editor.org/info/rfc7622>.

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[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>.

Acknowledgements

Thanks to Alexey Melnikov for suggestions on preparing this document.
Thanks to Alan Murdock, Yoav Nir, Peter Saint-Andre, and Kurt
Zeilenga for their review comments.

Author's Address

Steve Kille
Isode Ltd
14 Castle Mews
Hampton, Middlesex TW12 2NP
United Kingdom

Email: [email protected]

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