added more channel binding infrastructure

src/client.rs

@@ -68,11 +68,12 @@ impl ClientBuilder {
     /// Connects to the server and returns a `Client` when succesful.
     pub fn connect(self) -> Result<Client, Error> {
         let host = &self.host.unwrap_or(self.jid.domain.clone());
-        // TODO: channel binding
         let mut transport = SslTransport::connect(host, self.port)?;
         C2S::init(&mut transport, &self.jid.domain, "before_sasl")?;
         let (sender_out, sender_in) = channel();
         let (dispatcher_out, dispatcher_in) = channel();
+        let mut credentials = self.credentials.expect("can't connect without credentials");
+        credentials.channel_binding = transport.channel_bind();
         let mut client = Client {
             jid: self.jid,
             transport: transport,
@@ -81,7 +82,7 @@ impl ClientBuilder {
             sender_in: sender_in,
             dispatcher_in: dispatcher_in,
         };
-        client.connect(self.credentials.expect("can't connect without credentials"))?;
+        client.connect(credentials)?;
         client.bind()?;
         Ok(client)
     }

src/transport.rs

@@ -35,6 +35,11 @@ pub trait Transport {
 
     /// Resets the stream.
     fn reset_stream(&mut self);
+
+    /// Gets channel binding data.
+    fn channel_bind(&self) -> Option<Vec<u8>> {
+        None
+    }
 }
 
 /// A transport which uses STARTTLS.
@@ -73,6 +78,11 @@ impl Transport for SslTransport {
             .. Default::default()
         });
     }
+
+    fn channel_bind(&self) -> Option<Vec<u8>> {
+        // TODO: channel binding
+        None
+    }
 }
 
 impl SslTransport {