[JDEV] General Jabber Questions

[Schuyler Heath]

Hi Michael,

"Michael Brown" wrote:
> 
> A few general questions that I have been wondering about for a while.
> If this is documented somewhere and I have missed it, feel free to 
> point me in the right direction...
> 
http://docs.jabber.org has a lot of info.
>  
> 
> 1) Is there any support in the Jabber protocol to do a "Who is 
> watching me" query?  This would return a list of users who are 
> receiving your presence online (or who have subscribed to your 
> presence, even if they are not line at the time).  I think this would 
> be a great security feature, and something that ICQ has always been 
> lacking.
> 
Yep.  But you don't need to do a special query, it's all in your roster.
Look at http://docs.jabber.org/jpg/refiqroster.html (Roster) and http: 
//docs.jabber.org/jpg/refitem.html (Roster items).  The
'subscription' attribute contains this info.

>  
> 
> 2) Is there any way in the process of adding someone to your 
> roster/requesting a subscription to find out what their nickname is?  
> I know there is a nickname field in the vCard, but for most of the 
> clients I have seen you have to make up a nickname when you are adding 
> someone.  Is there an elegant way to handle this?
> 
Clients should do a vCard lookup and use the nickname field as the 
default.  But some clients don't support vCard yet.

>  
> 
> 3) Has anyone come up with a standard client-to-client encryption 
> standard that is recommended for each client to support?  I believe 
> encryption is left up to the client, but I am very worried that unless 
> this is coordinated it will result in the same insecure incompatible 
> mess that we currently have with email encryption systems.  I seem to 
> remember (from years ago) that the original vCard spec included a 
> field for a public key of some sort.  If we could use this to 
> implement a PGP (style) encryption method that would be very nice.  
> Maybe someone could point us to some standard Win32 libraries so that 
> we are all using the same method.
> 
Not yet, but we are working on doing this and PGP is a definite possibility.
>  
> 
> 4) Is it possible to implement an "Invisible" mode like ICQ's?  Maybe 
> I am doing something wrong, but if I connect and just don't send an 
> Available to the server, I can still send messages fine but I don't 
> seem to receive any until I go back Available again.  Presumably the 
> server holds onto the message until it thinks you are ready to read it...
> 
Yes, use a jabber:iq:filter query (mod_filter).  But mod_filter is post 
1.0 and not "officially" supported yet.
This  allows you to create a set of rules, that are stored on the 
server, to filter/redirect presence and messages.  You could add a rule 
that will prevent your presence from being sent to a single user, a 
group, or all.  So 'invisibility' in Jabber is achieved by filtering 
presence, not a special status mode.  AFAIK, the only mod_filter 
documentation that exists right now are the comments in the source.

Schuyler Heath
>  
> 
> Thanks,
> 
>  
> 
> Michael.
>