How can I send an image on the web in an XMPP (Jabber) message?

Question

For the XMPP interface for the Stack Overflow chat, I am currently taking the HTML of the chat messages and converting to valid XML, and setting that as the html child element of the XMPP message object. In my Mac OS X jabber client this was working great! It meant that when users in the SO chat posted a oneboxed image, the image would show up in my XMPP client (Adium for OS X):

However I just updated Adium to the latest version and apparently they considered what I was doing to be a security hole and against XMPP specs, and changed that behavior. Their reasoning was that XMPP should not reveal your Ip address, and to fetch an image over HTTP would reveal my IP address.

So now the chats are imageless over XMPP. How can I make images work over XMPP? Should my XMPP component download the images and embed them into the <Message> stanzas? Can the images be proxied through the XMPP server? Or is this an impossibility?

Answer 1

Adium, iChat and Pidgin all support XEP-0231, which allows you to send the provide binary data, including images to this purpose. Basically, it allows you to specify a unique identifier as the source for an image, and then the other client can decide if he wants to request the data in a <iq> request.

I've been working with this in python's Twisted, but meeting with some frustration. I do know that Adium and iChat at least use it to request the data.