[OTR-users] OTR for Facebook chat

Sat Mar 31 09:40:02 EDT 2012

Hello. Does OTR work for people using Facebook chat as the transport?

With Pidgin + OTR:
Gchat user -> Gchat user can OTR chat just fine.
Facebook user -> Facebook user : The initiator gets this:

<snip>
(14:33:17) jabber: Unable to find caps: nothing known about buddy

(14:33:17) jabber: Sending (ssl)
(HIDDEN at chat.facebook.com/Pidgin_09395de8_4BC89FC10217A): <message
type='chat' id='purplea497486' to='HIDDEN at chat.facebook.com'><active
xmlns='http://jabber.org/protocol/chatstates'/><body>?OTR?v2?
HIDDEN at chat.facebook.com/Pidgin has requested an Off-the-Record
private conversation <http://otr.cypherpunks.ca/>.  However, you
do not have a plugin to support that.
See http://otr.cypherpunks.ca/ for more information.</body><html
xmlns='http://jabber.org/protocol/xhtml-im'><body
xmlns='http://www.w3.org/1999/xhtml'><p>?OTR?v2?
<span style='font-weight:
bold;'>HIDDEN at chat.facebook.com/Pidgin</span> has requested an <a
href='http://otr.cypherpunks.ca/'>Off-the-Record private
conversation</a>.  However, you do not have a plugin to support that.
See <a href='http://otr.cypherpunks.ca/'>http://otr.cypherpunks.ca/</a>
for more information.</p></body></html></message>

(14:33:45) jabber: Sending (ssl)
(HIDDEN at chat.facebook.com/Pidgin_09395de8_4BC89FC10217A): <iq
type='get' id='purplea497487'><ping xmlns='urn:xmpp:ping'/></iq>

(14:33:46) jabber: Recv (ssl)(266): <iq
from="HIDDEN at chat.facebook.com"
to="HIDDEN at chat.facebook.com/Pidgin_09395de8_4BC89FC10217A"
type="error" id="purplea497487"><ping xmlns="urn:xmpp:ping"/><error
code="503" type="cancel"><service-unavailable
xmlns="urn:ietf:params:xml:ns:xmpp-stanzas"/></error></iq>

What does this 503 signify? Is OTR blocked/unsupported by FB's
implementation of XMPP, or something is temporarily down?

Thanks for any help,

Alex