Archive

Archive for October, 2010

a little (and probably short term) hope about detecting invisible buddies in Google Talk

a small variant of the first method to detect invisible buddies in Google Talk.


The first method consisted in starting a chat with the buddy we assumed invisible. If we got the message “[email protected] is offline and can’t receive messages right now.” then the buddy was offline but if didn’t appear any message then we could determine that our buddy was really invisible.


Now this bug has been fixed by Google but…


Let’s try to invite the invisible buddy in a group chat and see what happens…


In Pidgin this is quite easy: right click on the offline (invisible) buddy and click on “Start a chat”. This will start a group chat if the buddy is invisible.


Obviously this bug will have a short life and the method it’s not stealth (and difficult to apply to all buddies but not impossible) but for now…

Google fixed the “bug” to scan invisible buddies

It seems that Google has fixed what we used to consider a bug but was not properly a bug but simply an implementation choice.

From XMPP IM page:

5.1.3. Presence Probes

Upon receiving a presence probe from the user, the contact’s server SHOULD reply as follows:

3. Else, if the contact has no available resources, the server MUST either (1) reply to the presence probe by sending to the user the full XML of the last presence stanza of type “unavailable” received by the server from the contact, or (2) not reply at all.

obviously if we consider invisibility like a offline status we have to accept both cases. Until now we could scan invisible buddies because Google Server used two different behaviors for Offline and Invisible status.

And now?

Now the “half scan method” is no more useful. I don’t know any other method to do the same.

For now the only way I know to have information about invisible buddies is this plugin but it’s neither tested nor reliable and you have to be online when your buddies goes invisible.

Under Construction… ?

Now… installed WordPress to avoid that horrible index page but don’t expect too much from this little revolution. This site will probably be under construction for a looong long time.

Have fun!

Bulldozer