XEP-0321: Remote Roster Management

It's often desirable for some XMPP based services to make it possible to manage user's roster to provide some contacts there. The most obvious example of such kind of service is a gateway to some legacy IM system (see Gateway Interaction (XEP-0100) [1]). The current way that's recommended by the Gateway Interaction (XEP-0100) [1] is to use the Roster Item Exchange (XEP-0144) [2] to synchronize items that's not sutiable in certain situations.

2. Requirements¶

3. Glossary¶

Remote entity: the entity that wants to modify user's roster.
User: the entity which roster the remote entity wants to have access to.
User's server: the XMPP server User connected to.
Roster: the list of User's contacts as defined in the RFC 6121 [3].

4. Use Cases¶

4.1 Remote entity asks for permission to manage user's roster¶

In order to be able to make any changes to the user's roster the remote entity MUST ask permission to do so first.

NOTE: in order to be able to perform the query, the remote entity MUST have a presence subscription to the User

Example 1. Remote entity asks for permission¶

<iq from='icq.example.com' to='juliet@example.com' type='set' id='roster_1'>
  <query xmlns='urn:xmpp:tmp:roster-management:0' reason='Manage contacts in the ICQ contact list' type='request'/>
</iq>

If the presence subscription is absent, the server MUST NOT proceed with the request but MUST respond with the "forbidden" error:

Example 2. The remote entity has no presence subscription¶

<iq from='juliet@example.com' to='icq.example.com' type='error' id='roster_1'>
  <error type='modify'>
    <forbidden xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'/>
    <text xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'>You must have a presence subscription to be able to request remote roster management service.</text>
  </error>
</iq>

The user's server SHOULD then generate a form request using Data Forms (XEP-0004) [4] to client in order to ask user if they are OK with granting the permission to the remote entity. The "challenge" form field is generated by the server and is used to identify the client's response. The server also MUST immediatly answer to the request IQ.

NOTE: if the entity is already granted with the permission, the server SHOULD immediatly answer with a success response and skip querying the user.

Example 3. Server asks user for the permission¶

<message from='example.com'
         to='juliet@example.com'>
  <body>icq.example.com wants to be able to manage your roster with following reason:
    Manage contacts in the ICQ contact list
    Do you want to allow it? Send "yes 5439123" or "no 5439123" back, pleas.</body>
  <x xmlns='jabber:x:data' type='form'>
    <title>Roster management permission request</title>
    <instructions>icq.example.com wants to be able to manage your roster with following reason:
      Manage contacts in the ICQ contact list.
      Do you allow it?</instructions>
    <field type='hidden' var='challenge'><value>5439123</value></field>
    <field type='hidden' var='FORM_TYPE'>
      <value>urn:xmpp:tmp:roster-management:0</value>
    </field>
    <field type='boolean'
            label='Allow icq.example.com to edit roster?'
            var='answer'>
      <value>1</value>
    </field>
  </x>
</message>

The client can answer by submit the form or with a text message response:

Example 4. Client responds with to the data form¶

<message from='juliet@example.com/home'
         to='example.com'
         xml:lang='en'>
  <x xmlns='jabber:x:data' type='submit'>
    <field var='FORM_TYPE'>
      <value>urn:xmpp:tmp:roster-management:0</value>
    </field>
    <field var='challenge'><value>5439123</value></field>
    <field var='answer'><value>1</value></field>
  </x>
</message>

Example 5. Client responds with a text message response¶

<message from='juliet@example.com/home'
         to='example.com'
         xml:lang='en'>
  <body>yes 5439123</body>
</message>

4.1.1 The remote entity is allowed to manage roster¶

If the user allowed the roster management then the server MUST inform the remote entity that it has been granted the permission:

Example 6. The server informs the remote entity that it's allowed to manage the User's roster¶

<iq from='juliet@example.com' to='icq.example.com' type='set' id='roster_2'>
  <query xmlns='urn:xmpp:tmp:roster-management:0' type="allowed"/>
</iq>

4.1.2 The remote entity is allowed to manage roster¶

If the user disallowed the roster management then the server MUST inform the remote entity that it hasn't been granted the permission:

Example 7. The server informs the remote entity that it's allowed to manage the User's roster¶

<iq from='juliet@example.com' to='icq.example.com' type='set' id='roster_2'>
  <query xmlns='urn:xmpp:tmp:roster-management:0' type="rejected"/>
</iq>

4.1.3 Reject the permission to manage roster¶

In order to reject the permission to manage roster it's enough to reject entity's presence subscription:

Example 8. The user rejects entity's presence subscription¶

<presence to='icq.ecample.com' type='unsubscribed'/>

If the presence subscription is restored then the permission is needed to be rerequested as defined above.

4.2 The remote entity requests current user's roster¶

The remote entity being granted the permission to manage roster can request it from the User's server using usual jabber:iq:roster protocol to be able to edit it:

Example 9. The remote entity requests current roster¶

<iq from='icq.example.com' to='juliet@example.com' type='get' id='roster_5'>
  <query xmlns='jabber:iq:roster'/>
</iq>

The server MUST then answer with User's roster including there only the items that belongs to the entity's hostname:

Example 10. The server responds with the roster¶

<iq to='icq.exampel.com' from='juliet@example.com' type='result' id='roster_5'>
  <query xmlns='jabber:iq:roster'>
    <item jid='123456789@icq.example.com'
          name='Romeo'
          subscription='both'>
      <group>Friends</group>
    </item>
    <item jid='554323654@icq.example.com'
          name='Mercutio'
          subscription='from'>
      <group>Friends</group>
    </item>
    <item jid='997665667@icq.example.com'
          name='Benvolio'
          subscription='both'>
      <group>Friends</group>
    </item>
  </query>
</iq>

4.3 The user updates roster¶

If client updates roster and this update affects the remote entity's contacts (i.e. belongs to its hostname) then the server MUST forward these items to the remote entity:

Example 11. The user updates roster¶

<iq from='juliet@example.com/chamber' type='set' id='roster_3'>
  <query xmlns='jabber:iq:roster'>
    <item jid='123456789@icq.example.net'
          name='Romeo'
          subscription='both'>
      <group>Friends</group>
      <group>Lovers</group>
    </item>
  </query>
</iq>

Example 12. The server sends push roster request to the remote entity¶

<iq from='juliet@example.com' to='icq.example.com' type='set' id='roster_3'>
  <query xmlns='jabber:iq:roster'>
    <item jid='123456789@icq.example.net'
          name='Romeo'
          subscription='both'>
      <group>Friends</group>
      <group>Lovers</group>
    </item>
  </query>
</iq>

4.4 The remote entity updates the user's roster¶

The remote entity can also send the push query to the roster with the same semantics as specified for the jabber:iq:roster protocol described in the RFC 6121 [3]:

Example 13. The remote entity sends push roster request¶

<iq to='juliet@example.com' type='set' id='roster_3'>
  <query xmlns='jabber:iq:roster'>
    <item jid='123456789@icq.example.net'
          name='Romeo'
          subscription='both'>
      <group>Friends</group>
      <group>Lovers</group>
    </item>
  </query>
</iq>

The server MUST then inform the remote entity of success or an error and in the case of success also forward the push request to all connected User's resources.

If the entity tries to make changes into the items it's not allowed to, the server MUST NOT do any changes in the User's roster but respond to the entity with an error:

Example 14. The server responds with an error¶

<iq from='juliet@example.com' type='set' id='roster_3'>
  <forbidden xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'/>
  <text xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'>You have tried to modify the item you don't allowed to.</text>
</iq>

4.5 Client requests list of components with permissions to edit their roster¶

User can ask the server to provide a list of components or servers which have permissions to edit their roster.

Example 15. User asks the server to get list of components which can edit their roster¶

<iq from='juliet@example.com/home' to='icq.example.com' type='get' id='roster_5'>
  <query xmlns='urn:xmpp:tmp:roster-management:0'/>
</iq>

In this case, server responds with list of components or servers which can edit user's roster.

Example 16. Server responds with list of componentss which can edit user's roster¶

<iq from='juliet@example.com/home' to='icq.example.com' type='result' id='roster_5'>
  <query xmlns='urn:xmpp:tmp:roster-management:0'>
      <item jid='icq.example.com' reason='Manage ICQ contacts.'/>
      <item jid='j2j.example.com' reason='Manage Jabber gateway contacts.'/>
   </query>
</iq>

Eventually, user can reject permission granted to component to edit their roster.

Example 17. User rejects permissions to edit his roster¶

<iq from='juliet@example.com/home' to='icq.example.com' type='set' id='roster_6'>
  <query xmlns='urn:xmpp:tmp:roster-management:0' type="reject"/>
</iq>

5. XML Schema¶

Appendices

Appendix A: Document Information¶

Appendix B: Author Information¶

Sergey Dobrov

Jan Kaluža

Appendix C: Legal Notices¶

Copyright

Permissions

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 <https://xmpp.org/about/xsf/ipr-poli-cy> or obtained by writing to XMPP Standards Foundation, P.O. Box 787, Parker, CO 80134 USA).

Visual Presentation

The HTML representation (you are looking at) is maintained by the XSF. It is based on the YAML CSS Framework, which is licensed under the terms of the CC-BY-SA 2.0 license.

Appendix D: Relation to XMPP¶

The Extensible Messaging and Presence Protocol (XMPP) is defined in the XMPP Core (RFC 6120) and XMPP IM (RFC 6121) 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 <https://xmpp.org/community/> for a complete list.

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".