<auth mechanism="X-FACEBOOK-PLATFORM" xmlns="urn:ietf:params:xml:ns:xmpp-sasl"></auth>
<challenge xmlns="urn:ietf:params:xml:ns:xmpp-sasl">dmVyc2lvbj0xJm1ldGhvZD1hdXRoLnhtcHBfbG9naW4mbm9uY2U9RDlBMTExNUIyQjVEMUQ2MTYyREQ3RDI4QUQ1QTQzN0U=</challenge>
<response xmlns="urn:ietf:params:xml:ns:xmpp-sasl">YXBpX2tleT1kYjJlYTljYzQ4YWI3OGQ5YTRhMmM5ODZiMjZiMGU4MSZjYWxsX2lkPTEyODQ2MTcxMTEmbWV0aG9kPWF1dGgueG1wcF9sb2dpbiZub25jZT1EOUExMTE1QjJCNUQxRDYxNjJERDdEMjhBRDVBNDM3RSZzZXNzaW9uX2tleT0xNjIxNzE0NjA0NTk5ODUlMjU3Y2IzNGNhMjk3MmEzYmY4YTNhYWM3OGQ3MS01MDMxNTk3MzIlMjU3Y3V4Ym1fenNraXN0Y2p3ZXdndHZmejZsdGw0OCZ2PTEuMCZzaWc9ZjA0YTFmODk1YzA0ZWE5NDIzODhjNDU4YjQzMzkzMDQ=</response>
<failure xmlns="urn:ietf:params:xml:ns:xmpp-sasl"><not-authorized/></failure>
That's the response I get :(
I use the API_KEY, Application Secret, and the session key..to generate the response...
It's all in the code. I can tell you what classes are important.