XEP-0267: Server Rosters

Abstract:This specification defines a convention for trust between XMPP server deployments.
Authors:Artur Hefczyc, Florian Jensen, Mickaël Rémond, Peter Saint-Andre, Matthew Wild
Copyright:© 1999 - 2011 XMPP Standards Foundation. SEE LEGAL NOTICES.
Type:Standards Track
Last Updated:2009-04-30

WARNING: Consideration of this document has been Deferred by the XMPP Standards Foundation. Implementation of the protocol described herein is not recommended.

Table of Contents

1. Description
2. Security Considerations
3. IANA Considerations
4. XMPP Registrar Considerations

    A: Document Information
    B: Author Information
    C: Legal Notices
    D: Relation to XMPP
    E: Discussion Venue
    F: Requirements Conformance
    G: Notes
    H: Revision History

1. Description

In XMPP, rosters and presence subscriptions have been used to date only among IM users (see XMPP IM [1]). However, nothing prevents the application of these concepts to other XMPP entities, such as components and servers. Given that a presence subscription typically indicates some level of trust in a peer, server deployments can use the sharing of XMPP presence information as a way to indicate that a given server has a trust relationship with a peer server. The server might then share certain kinds of additional information only with trusted peers, for example Incident Reporting [2].

To establish a trust relationship with a peer, a server shall send a presence subscription request to the peer, just as is done between XMPP users.

Example 1. Service sends subscription request to peer

<presence from='montague.lit'

A server MUST NOT send such a presence subscription request unless explicitly requested to do so by the server administrator(s).

Upon receiving such a presence subscription request, the XMPP server software running at the peer MUST prompt the server administrator(s) to approve the request, rather than automatically approving it. Methods for doing so are out of scope for this specification.

If the server administrator(s) approve the request, the peer server shall then inform the originating server that the request has been approved.

Example 2. Peer sends approval to server

<presence from='capulet.lit'

The peer SHOULD also send a subscription request to the originating server.

Example 3. Peer sends subscription request to server

<presence from='capulet.lit'

If an XMPP server implementation supports this usage of presence subscriptions, it MUST keep a list of approved entities, which we denote a "server roster". The implementation MAY use that roster for access control purposes defined in other specifications.

2. Security Considerations

To follow.

3. IANA Considerations

This document requires no interaction with the Internet Assigned Numbers Authority (IANA) [3].

4. XMPP Registrar Considerations

This document requires no interaction with the XMPP Registrar [4].


Appendix A: Document Information

Series: XEP
Number: 0267
Publisher: XMPP Standards Foundation
Status: Deferred
Type: Standards Track
Version: 0.1
Last Updated: 2009-04-30
Approving Body: XMPP Council
Dependencies: XMPP Core
Supersedes: None
Superseded By: None
Source Control: HTML
This document in other formats: XML  PDF

Appendix B: Author Information

Artur Hefczyc

Email: artur.hefczyc@gmail.com
JabberID: artur.hefczyc@tigase.org

Florian Jensen

Email: admin@flosoft.biz
JabberID: admin@im.flosoft.biz

Mickaël Rémond

Email: mickael.remond@process-one.net
JabberID: mremond@process-one.net

Peter Saint-Andre

Email: stpeter@jabber.org
JabberID: stpeter@jabber.org
URI: https://stpeter.im/

Matthew Wild

Email: mwild1@gmail.com
JabberID: mwild1@jaim.at

Appendix C: Legal Notices


This XMPP Extension Protocol is copyright © 1999 - 2011 by the XMPP Standards Foundation (XSF).


Permission is hereby granted, free of charge, to any person obtaining a copy of this specification (the "Specification"), to make use of the Specification without restriction, including without limitation the rights to implement the Specification in a software program, deploy the Specification in a network service, and copy, modify, merge, publish, translate, distribute, sublicense, or sell copies of the Specification, and to permit persons to whom the Specification is furnished to do so, subject to the condition that the foregoing copyright notice and this permission notice shall be included in all copies or substantial portions of the Specification. Unless separate permission is granted, modified works that are redistributed shall not contain misleading information regarding the authors, title, number, or publisher of the Specification, and shall not claim endorsement of the modified works by the authors, any organization or project to which the authors belong, or the XMPP Standards Foundation.

Disclaimer of Warranty

## NOTE WELL: This Specification is provided on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, express or implied, including, without limitation, any warranties or conditions of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A PARTICULAR PURPOSE. ##

Limitation of Liability

In no event and under no legal theory, whether in tort (including negligence), contract, or otherwise, unless required by applicable law (such as deliberate and grossly negligent acts) or agreed to in writing, shall the XMPP Standards Foundation or any author of this Specification be liable for damages, including any direct, indirect, special, incidental, or consequential damages of any character arising from, out of, or in connection with the Specification or the implementation, deployment, or other use of the Specification (including but not limited to damages for loss of goodwill, work stoppage, computer failure or malfunction, or any and all other commercial damages or losses), even if the XMPP Standards Foundation or such author has been advised of the possibility of such damages.

IPR Conformance

This XMPP Extension Protocol has been contributed in full conformance with the XSF's Intellectual Property Rights Policy (a copy of which can be found at <http://xmpp.org/about-xmpp/xsf/xsf-ipr-policy/> or obtained by writing to XMPP Standards Foundation, 1899 Wynkoop Street, Suite 600, Denver, CO 80202 USA).

Appendix D: Relation to XMPP

The Extensible Messaging and Presence Protocol (XMPP) is defined in the XMPP Core (RFC 3920) and XMPP IM (RFC 3921) specifications contributed by the XMPP Standards Foundation to the Internet Standards Process, which is managed by the Internet Engineering Task Force in accordance with RFC 2026. Any protocol defined in this document has been developed outside the Internet Standards Process and is to be understood as an extension to XMPP rather than as an evolution, development, or modification of XMPP itself.

Appendix E: Discussion Venue

The primary venue for discussion of XMPP Extension Protocols is the <standards@xmpp.org> discussion list.

Discussion on other xmpp.org discussion lists might also be appropriate; see <http://xmpp.org/about/discuss.shtml> for a complete list.

Errata can be sent to <editor@xmpp.org>.

Appendix F: Requirements Conformance

The following requirements keywords as used in this document are to be interpreted as described in RFC 2119: "MUST", "SHALL", "REQUIRED"; "MUST NOT", "SHALL NOT"; "SHOULD", "RECOMMENDED"; "SHOULD NOT", "NOT RECOMMENDED"; "MAY", "OPTIONAL".

Appendix G: Notes

1. RFC 6121: Extensible Messaging and Presence Protocol (XMPP): Instant Messaging and Presence <http://tools.ietf.org/html/rfc6121>.

2. XEP-0268: Incident Reporting <http://xmpp.org/extensions/xep-0268.html>.

3. The Internet Assigned Numbers Authority (IANA) is the central coordinator for the assignment of unique parameter values for Internet protocols, such as port numbers and URI schemes. For further information, see <http://www.iana.org/>.

4. The XMPP Registrar maintains a list of reserved protocol namespaces as well as registries of parameters used in the context of XMPP extension protocols approved by the XMPP Standards Foundation. For further information, see <http://xmpp.org/registrar/>.

Appendix H: Revision History

Note: Older versions of this specification might be available at http://xmpp.org/extensions/attic/

Version 0.1 (2009-04-30)

Initial published version.


Version 0.0.1 (2009-04-30)

First draft, split from the incident reporting proposal.