add client_auth using sasl

src/client_auth.rs

@@ -0,0 +1,160 @@
+use std::mem::replace;
+use futures::*;
+use futures::sink;
+use tokio_io::{AsyncRead, AsyncWrite};
+use xml;
+use sasl::common::Credentials;
+use sasl::common::scram::*;
+use sasl::client::Mechanism;
+use sasl::client::mechanisms::*;
+use serialize::base64::{self, ToBase64, FromBase64};
+
+use xmpp_codec::*;
+use xmpp_stream::*;
+
+const NS_XMPP_SASL: &str = "urn:ietf:params:xml:ns:xmpp-sasl";
+
+pub struct ClientAuth<S: AsyncWrite> {
+    state: ClientAuthState<S>,
+    mechanism: Box<Mechanism>,
+}
+
+enum ClientAuthState<S: AsyncWrite> {
+    WaitSend(sink::Send<XMPPStream<S>>),
+    WaitRecv(XMPPStream<S>),
+    Invalid,
+}
+
+impl<S: AsyncWrite> ClientAuth<S> {
+    pub fn new(stream: XMPPStream<S>, creds: Credentials) -> Result<Self, String> {
+        let mechs: Vec<Box<Mechanism>> = vec![
+            Box::new(Scram::<Sha256>::from_credentials(creds.clone()).unwrap()),
+            Box::new(Scram::<Sha1>::from_credentials(creds.clone()).unwrap()),
+            Box::new(Plain::from_credentials(creds).unwrap()),
+            Box::new(Anonymous::new()),
+        ];
+
+        println!("stream_features: {}", stream.stream_features);
+        let mech_names: Vec<String> =
+            match stream.stream_features.get_child("mechanisms", Some(NS_XMPP_SASL)) {
+                None =>
+                    return Err("No auth mechanisms".to_owned()),
+                Some(mechs) =>
+                    mechs.get_children("mechanism", Some(NS_XMPP_SASL))
+                    .map(|mech_el| mech_el.content_str())
+                    .collect(),
+            };
+        println!("Offered mechanisms: {:?}", mech_names);
+
+        for mut mech in mechs {
+            let name = mech.name().to_owned();
+            if mech_names.iter().any(|name1| *name1 == name) {
+                println!("Selected mechanism: {:?}", name);
+                let initial = try!(mech.initial());
+                let mut this = ClientAuth {
+                    state: ClientAuthState::Invalid,
+                    mechanism: mech,
+                };
+                this.send(
+                    stream,
+                    "auth", &[("mechanism".to_owned(), name)],
+                    &initial
+                );
+                return Ok(this);
+            }
+        }
+
+        Err("No supported SASL mechanism available".to_owned())
+    }
+
+    fn send(&mut self, stream: XMPPStream<S>, nonza_name: &str, attrs: &[(String, String)], content: &[u8]) {
+        let mut nonza = xml::Element::new(
+            nonza_name.to_owned(),
+            Some(NS_XMPP_SASL.to_owned()),
+            attrs.iter()
+                .map(|&(ref name, ref value)| (name.clone(), None, value.clone()))
+                .collect()
+        );
+        nonza.text(content.to_base64(base64::URL_SAFE));
+
+        println!("send {}", nonza);
+        let send = stream.send(Packet::Stanza(nonza));
+
+        self.state = ClientAuthState::WaitSend(send);
+    }
+}
+
+impl<S: AsyncRead + AsyncWrite> Future for ClientAuth<S> {
+    type Item = XMPPStream<S>;
+    type Error = String;
+
+    fn poll(&mut self) -> Poll<Self::Item, Self::Error> {
+        let state = replace(&mut self.state, ClientAuthState::Invalid);
+
+        match state {
+            ClientAuthState::WaitSend(mut send) =>
+                match send.poll() {
+                    Ok(Async::Ready(stream)) => {
+                        println!("send done");
+                        self.state = ClientAuthState::WaitRecv(stream);
+                        self.poll()
+                    },
+                    Ok(Async::NotReady) => {
+                        self.state = ClientAuthState::WaitSend(send);
+                        Ok(Async::NotReady)
+                    },
+                    Err(e) =>
+                        Err(format!("{}", e)),
+                },
+            ClientAuthState::WaitRecv(mut stream) =>
+                match stream.poll() {
+                    Ok(Async::Ready(Some(Packet::Stanza(ref stanza))))
+                        if stanza.name == "challenge"
+                        && stanza.ns == Some(NS_XMPP_SASL.to_owned()) =>
+                    {
+                        let content = try!(
+                            stanza.content_str()
+                                .from_base64()
+                                .map_err(|e| format!("{}", e))
+                        );
+                        let response = try!(self.mechanism.response(&content));
+                        self.send(stream, "response", &[], &response);
+                        self.poll()
+                    },
+                    Ok(Async::Ready(Some(Packet::Stanza(ref stanza))))
+                        if stanza.name == "success"
+                        && stanza.ns == Some(NS_XMPP_SASL.to_owned()) =>
+                        Ok(Async::Ready(stream)),
+                    Ok(Async::Ready(Some(Packet::Stanza(ref stanza))))
+                        if stanza.name == "failure"
+                        && stanza.ns == Some(NS_XMPP_SASL.to_owned()) =>
+                    {
+                        let mut e = None;
+                        for child in &stanza.children {
+                            match child {
+                                &xml::Xml::ElementNode(ref child) => {
+                                    e = Some(child.name.clone());
+                                    break
+                                },
+                                _ => (),
+                            }
+                        }
+                        let e = e.unwrap_or_else(|| "Authentication failure".to_owned());
+                        Err(e)
+                    },
+                    Ok(Async::Ready(event)) => {
+                        println!("ClientAuth ignore {:?}", event);
+                        Ok(Async::NotReady)
+                    },
+                    Ok(_) => {
+                        self.state = ClientAuthState::WaitRecv(stream);
+                        Ok(Async::NotReady)
+                    },
+                    Err(e) =>
+                        Err(format!("{}", e)),
+                },
+            ClientAuthState::Invalid =>
+                unreachable!(),
+        }
+    }
+}