<?xml version='1.0' encoding='UTF-8'?> <!DOCTYPE xep SYSTEM 'xep.dtd' [ <!ENTITY % ents SYSTEM 'xep.ent'> %ents; ]> <?xml-stylesheet type='text/xsl' href='xep.xsl'?> <xep> <header> <title>Unique Room Names for Multi-User Chat</title> <abstract>This specification defines an XMPP protocol extension for requesting a unique room ID from a multi-user chat service.</abstract> &LEGALNOTICE; <number>0307</number> <status>Deferred</status> <type>Standards Track</type> <sig>Standards</sig> <dependencies> <spec>XMPP Core</spec> <spec>XEP-0045</spec> </dependencies> <supersedes/> <supersededby/> <shortname>muc-unique</shortname> <schemaloc> <url>http://www.xmpp.org/schemas/muc-unique.xsd</url> </schemaloc> &stpeter; <revision> <version>0.1</version> <date>2011-11-10</date> <initials>psa</initials> <remark><p>Initial published version.</p></remark> </revision> <revision> <version>0.0.1</version> <date>2011-09-26</date> <initials>psa</initials> <remark><p>First version, moved from XEP-0045.</p></remark> </revision> </header> <section1 topic='Introduction' anchor='intro'> <p>&xep0045; defines the protocol for groupchat in XMPP. In some situations, the room creator may want to request a unique room name before attempting to create the room (e.g., to avoid the possibility of a room conflict). Naturally, one way to do so is for the creator's client to generate a globally unique identifier, for example as defined in &rfc4122;. Another way is for the client to ask the MUC service for a unique room ID (which the service will thus reserve for that user).</p> </section1> <section1 topic='Protocol' anchor='proto'> <p>The room creator requests a unique room name by sending an IQ-get to the service itself, containing an empty <unique/> element qualified by the 'http://jabber.org/protocol/muc#unique' namespace:</p> <example caption='Entity Requests Unique Room Name'><![CDATA[ <iq from='crone1@shakespeare.lit/desktop' id='unique1' to='chat.shakespeare.lit' type='get'> <unique xmlns='http://jabber.org/protocol/muc#unique'/> </iq> ]]></example> <p>If the service supports this feature, it SHOULD return a unique room name as the XML character data of the <unique/> element (but not create the room):</p> <example caption='Service Returns Unique Room Name'><![CDATA[ <iq from='chat.shakespeare.lit' id='unique1' to='crone1@shakespeare.lit/desktop' type='result'> <unique xmlns='http://jabber.org/protocol/muc#unique'> 6d9423a55f499b29ad20bf7b2bdea4f4b885ead1 </unique> </iq> ]]></example> <p>The service MAY refuse to return a unique room name to entities that are not entitled to create rooms, entities that have sent an excessive number of requests for unique room names, etc.</p> <p>The service MAY use any algorithm that ensures the creation of a room name that will be permanently unique in the context of the service (e.g., a cryptographic hash of the requesting JID, datetime, and random salt), or simply use a UUID as defined by <cite>RFC 4122</cite>.</p> <p>The room creator would then use the XML character data of the <unique/> element as the node identifier portion of the room JID it requests:</p> <example caption='Owner Creates Room With Unique Name'><![CDATA[ <presence from='crone1@shakespeare.lit/desktop' to='6d9423a55f499b29ad20bf7b2bdea4f4b885ead1@chat.shakespeare.lit/firstwitch'> <x xmlns='http://jabber.org/protocol/muc'/> </presence> ]]></example> </section1> <section1 topic='Determining Support' anchor='support'> <p>If a MUC service supports the protocol specified herein, it MUST advertise that fact by returning a feature of "http://jabber.org/protocol/muc#unique" in response to &xep0030; information requests &NSNOTE;.</p> <example caption="Service discovery information request"><![CDATA[ <iq from='crone1@shakespeare.lit/desktop' id='disco1' to='chat.shakespeare.lit' type='get'> <query xmlns='http://jabber.org/protocol/disco#info'/> </iq> ]]></example> <example caption="Service discovery information response"><![CDATA[ <iq from='chat.shakespeare.lit' id='disco1' to='crone1@shakespeare.lit/desktop' type='result'> <query xmlns='http://jabber.org/protocol/disco#info'> [...] <feature var='http://jabber.org/protocol/muc#unique'/> [...] </query> </iq> ]]></example> </section1> <section1 topic='XML Schema' anchor='schema'> <code><![CDATA[ <?xml version='1.0' encoding='UTF-8'?> <xs:schema xmlns:xs='http://www.w3.org/2001/XMLSchema' targetNamespace='http://jabber.org/protocol/muc#unique' xmlns='http://jabber.org/protocol/muc#unique' elementFormDefault='qualified'> <xs:element name='unique' type='xs:string'/> </xs:schema> ]]></code> </section1> </xep>