[JDEV] MUC problems

Constantin Nickonov Nickonov at jabber.com
Tue Feb 11 11:28:55 CST 2003


I understand what you're trying to do. The problem is that your methods
conflict with the intent of JEP-0045, which will eventually result in
fragmentation of the standard, i.e., when two or more implementations of MUC
accomplish the same thing in incompatible ways. Perhaps the JEP should be
more specific when it comes to laying out the 'jabber:iq:browse'
capabilities (which are being phased out in favor of disco), but it seems to
me the re-introduction of SHA-hashing for this purpose is not a good thing.

Sure, you can talk about race conditions, like when I browse to get a list
of users and one of them chooses that moment to change his nick, making my
subsequent user-level browse requests invalid. But why not just return the
real JID (if it's allowed by the room) in the room-level browse result?
Something like this:

SENT: <iq type='get' to='room at muc.server'>
        <query xmlns='jabber:iq:browse'/>
      </iq>
READ: <iq type='result' to='user at server/resource' from='room at muc.server'>
        <conference xmlns='jabber:iq:browse' name='room' type='public'>
          <ns>http://jabber.org/protocol/muc</ns>
          <user name='nick1' jid='user2 at server/resource'/>
        </conference>
      </iq>

In the case of an anonymous room, the 'jid' attribute could be omitted (or
contain the in-room JID for that user, i.e., 'room at muc.server/nick2').

> -----Original Message-----
> From: David Sutton [mailto:jabber at dsutton.legend.uk.com]
> Sent: Tuesday, February 11, 2003 8:59 AM
> To: jdev at jabber.org
> Subject: Re: [JDEV] MUC problems
> 
> 
> Hello there,
> 
>   We are both correct in this situation. The JEP does define 
> how the jid
>   is to be handled for a presence packet, and MU-Conference follows
>   that. You will never see the SHA1 string in a presence packet. 
> 
>   On the other hand, the system of using an iq request, xmlns
>   jabber:iq:browse, to discover the room roster is not covered by the 
>   JEP. In order to maintain sanity, I have opted to continue using the
>   existing methods. If you require to see the real jid, and you are
>   allowed, then browsing the SHA1 resource will reveal the true jid. I
>   have to use the sha1, since it allows you to track the user more
>   consistantly - as I tried to explain before, I could use
>   'girls at conference.localhost/NICK' for the nickname reported 
> by browse,
>   the problem is that if users swap nicknames, I have no way 
> of knowing
>   that is what happened. The SHA1 string is unique to that user.
> 
> Regards,
> 
>   David
> 
> On Tue, Feb 11, 2003 at 08:12:16AM -0700, Constantin Nickonov wrote:
> > see below
> > 
> > > -----Original Message-----
> > > From: David Sutton [mailto:jabber at dsutton.legend.uk.com]
> > > Sent: Monday, February 10, 2003 8:51 PM
> > > To: jdev at jabber.org
> > > Subject: Re: [JDEV] MUC problems
> > 
> > <snip>
> > 
> > > The hex string is actually a SHA1 hash of the users real 
> jid. Its used
> > > to reference a user, but not reveal the true jid. If the room 
> > > is set up to allow people to see the real jid, then just browse
> > > 
> girls at conference.localhost/13c6a01dc31309e331c2b018640b9c03b85
> 34327 and
> > > it will show you the true jid. This also helps to keep 
> compatability to
> > > existing clients that are used to this form with the
> > > groupchat/conferencing module. The real jid is used as 
> the reference, as
> > > a person can keep changing their nick throughout a 
> session, but they
> > > can't change their real jid
> > 
> > The problem with this is that the MUC standard (JEP-0045) 
> specifies how
> > nicknames are passed along with presence information, and 
> how they are
> > changed -- and SHA-hashing isn't the way.
> > 
> > Entering a room (JEP-0045, section 6.2):
> > 
> >   SENT: <presence to='foo at muc.server/nick1'>
> >           <x xmlns='http://jabber.org/protocol/muc'/>
> >         </presence>
> >   READ: <presence from='foo at muc.server/nick1' 
> to='user at server/resource'>
> >           <x xmlns='http://jabber.org/protocol/muc#user'>
> >             <item affiliation='owner' jid='user at server/resource'
> > role='moderator'/>
> >           </x>
> >         </presence>
> > 
> > Changing the nick (JEP-0045, section 6.4):
> > 
> >   SENT: <presence to='foo at muc.server/nick2'/>
> >   READ: <presence type='unavailable' from='foo at muc.server/nick1'
> > to='user at server/resource'>
> >           <x xmlns='http://jabber.org/protocol/muc#user'>
> >             <item nick='nick2' affiliation='owner'
> > jid='user at server/resource' role='moderator'/>
> >             <status code='303'/>
> >           </x>
> >         </presence>
> >         <presence from='foo at muc.server/nick2' 
> to='user at server/resource'>
> >           <x xmlns='http://jabber.org/protocol/muc#user'>
> >             <item affiliation='owner' jid='user at server/resource'
> > role='moderator'/>
> >           </x>
> >         </presence>
> > 
> > The MUC protocol wasn't designed to be fully 
> backward-compatible with the
> > JCF draft.
> > 
> > Constantin
> > _______________________________________________
> > jdev mailing list
> > jdev at jabber.org
> > http://mailman.jabber.org/listinfo/jdev
> 
> -- 
> David Sutton
> Email: dsutton at legend.co.uk
> Jabber: peregrine at legend.net.uk
> 



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