facebook chat authentication using the X-FACEBOOK-PLATFORM SASL authentication

Question

I'm dealing with the facebook chat authentication using the X-FACEBOOK-PLATFORM SASL authentication mechanism.

I'm forming the user and password as explained in the facebook developer forum and the stackoverflow question.

The point is if I use the application_secret as password I can login, but according to the stackoverflow question (link below) it should be a session generated from the old rest api method auth.promoteSession

I want to use the old rest api method, in order to avoid distributing the application_secret in our desktop application jars.

So the question is, how have you managed to login with the auth.promoteSession????

I have read the following posts which have been of great help:

http://community.igniterealtime.org/message/205739#205739
XMPP with Java Asmack library supporting X-FACEBOOK-PLATFORM

And I'm using the class SASLXFacebookPlatformMechanism.java which comes fromt the igniterealtime post and it is registered correclty.

I have the xmpp_login and offline_access permisions. And I have disabled the Remove Deprecated Auth Methods, so I can called the old rest api methods, in this case: auth.promoteSession I'm using the client-side flow authentication into facebook as well.

So, using the application_secret as password I get:

<stream:features><mechanisms xmlns="urn:ietf:params:xml:ns:xmpp-sasl"><mechanism>X-FACEBOOK-PLATFORM</mechanism><mechanism>DIGEST-MD5</mechanism></mechanisms></stream:features>
<challenge xmlns="urn:ietf:params:xml:ns:xmpp-sasl">dmVyc2lvbj0xJm1ldGhvZD1hdXRoLnhtcHBfbG9naW4mbm9uY2U9NEIxRUQzNTA5MTQ5MDQxRTE4N0QyNTA0NTUzNjBDQjc=</challenge>
<success xmlns="urn:ietf:params:xml:ns:xmpp-sasl"/>

But if I use the value returned by the auth.promoteSession I get:

<stream:features><mechanisms xmlns="urn:ietf:params:xml:ns:xmpp-sasl"><mechanism>X-FACEBOOK-PLATFORM</mechanism><mechanism>DIGEST-MD5</mechanism></mechanisms></stream:features>
<challenge xmlns="urn:ietf:params:xml:ns:xmpp-sasl">dmVyc2lvbj0xJm1ldGhvZD1hdXRoLnhtcHBfbG9naW4mbm9uY2U9MzhFQkUxOTUxNENGRUU4ODc2NzRDREQ0RjhBMUQ0QjI=</challenge>
<failure xmlns="urn:ietf:params:xml:ns:xmpp-sasl"><not-authorized/></failure>

Answer 1

I have changed the version for Android and it works for me now

public class SASLXFacebookPlatformMechanism extends SASLMechanism {

    private static final String NAME              = "X-FACEBOOK-PLATFORM";

    private String              apiKey            = "";
    private String              accessToken        = "";

    /**
     * Constructor.
     */
    public SASLXFacebookPlatformMechanism(SASLAuthentication saslAuthentication) {
        super(saslAuthentication);
    }

    @Override
    protected void authenticate() throws IOException, XMPPException {
        getSASLAuthentication().send(new AuthMechanism(NAME, ""));
    }

    @Override
    public void authenticate(String apiKey, String host, String accessToken) throws IOException, XMPPException {
        if (apiKey == null || accessToken == null) {
            throw new IllegalArgumentException("Invalid parameters");
        }

        this.apiKey = apiKey;
        this.accessToken = accessToken;
        this.hostname = host;

        String[] mechanisms = { "DIGEST-MD5" };
        Map<String, String> props = new HashMap<String, String>();
        this.sc = Sasl.createSaslClient(mechanisms, null, "xmpp", host, props, this);
        authenticate();
    }

    @Override
    public void authenticate(String username, String host, CallbackHandler cbh) throws IOException, XMPPException {
        String[] mechanisms = { "DIGEST-MD5" };
        Map<String, String> props = new HashMap<String, String>();
        this.sc = Sasl.createSaslClient(mechanisms, null, "xmpp", host, props, cbh);
        authenticate();
    }

    @Override
    protected String getName() {
        return NAME;
    }

    @Override
    public void challengeReceived(String challenge) throws IOException {
        byte[] response = null;

        if (challenge != null) {
            String decodedChallenge = new String(Base64.decode(challenge));
            Map<String, String> parameters = getQueryMap(decodedChallenge);

            String version = "1.0";
            String nonce = parameters.get("nonce");
            String method = parameters.get("method");

            String composedResponse =
                "method=" + URLEncoder.encode(method, "utf-8") +
                        "&nonce=" + URLEncoder.encode(nonce, "utf-8") +
                        "&access_token=" + URLEncoder.encode(accessToken, "utf-8") +
                        "&api_key=" + URLEncoder.encode(apiKey, "utf-8") +
                        "&call_id=0" +
                        "&v=" + URLEncoder.encode(version, "utf-8");
            response = composedResponse.getBytes();
        }

        String authenticationText = "";

        if (response != null) {
            authenticationText = Base64.encodeBytes(response);
        }

        // Send the authentication to the server
        getSASLAuthentication().send(new Response(authenticationText));
    }

    private Map<String, String> getQueryMap(String query) {
        Map<String, String> map = new HashMap<String, String>();
        String[] params = query.split("\\&");

        for (String param : params) {
            String[] fields = param.split("=", 2);
            map.put(fields[0], (fields.length > 1 ? fields[1] : null));
        }

        return map;
    }
}

This version requires only application id and access token

ConnectionConfiguration config = new ConnectionConfiguration("chat.facebook.com", 5222);
config.setSASLAuthenticationEnabled(true);
mFbConnection = new XMPPConnection(config);

try {
    SASLAuthentication.registerSASLMechanism("X-FACEBOOK-PLATFORM", SASLXFacebookPlatformMechanism.class);
    SASLAuthentication.supportSASLMechanism("X-FACEBOOK-PLATFORM", 0);
    mFbConnection.connect();
    mFbConnection.login(apiKey, accessToken, "Application");
} catch (XMPPException e) {
    mFbConnection.disconnect();
    e.printStackTrace();
}

I hope this will help.

Answer 2

Yes it apears to me, you need both. The code from XMPP with Java Asmack library supporting X-FACEBOOK-PLATFORM needed adjusting to include the application secret, as well as the session secret (as the password).

this.apiKey = keyArray[0];
    Log.d("API_KEY", apiKey);
    this.applicationSecret = "################################";
    Log.d("SECRET_KEY", applicationSecret);
    this.sessionKey = keyArray[1];
    Log.d("SESSION_KEY", sessionKey);

    this.authenticationId = sessionKey;
    this.password = applicationSecret;
    this.hostname = host;

swaping out the ######################## for your appSecret (found in your dev area)

This is not clear from the docs or the post IMO. Session secret was aquired through FB.getSession() but other options work too.