Moved starttls connector to tokio_xmpp::connect::starttls module

tokio-xmpp/src/connect/starttls.rs

@@ -0,0 +1,206 @@
+//! `starttls::ServerConfig` provides a `ServerConnector` for starttls connections
+
+#[cfg(feature = "tls-native")]
+use native_tls::Error as TlsError;
+use std::error::Error as StdError;
+use std::fmt;
+#[cfg(all(feature = "tls-rust", not(feature = "tls-native")))]
+use tokio_rustls::rustls::pki_types::InvalidDnsNameError;
+#[cfg(all(feature = "tls-rust", not(feature = "tls-native")))]
+use tokio_rustls::rustls::Error as TlsError;
+
+use futures::{sink::SinkExt, stream::StreamExt};
+
+#[cfg(all(feature = "tls-rust", not(feature = "tls-native")))]
+use {
+    std::sync::Arc,
+    tokio_rustls::{
+        client::TlsStream,
+        rustls::pki_types::ServerName,
+        rustls::{ClientConfig, RootCertStore},
+        TlsConnector,
+    },
+};
+
+#[cfg(feature = "tls-native")]
+use {
+    native_tls::TlsConnector as NativeTlsConnector,
+    tokio_native_tls::{TlsConnector, TlsStream},
+};
+
+use minidom::Element;
+use sasl::common::ChannelBinding;
+use tokio::{
+    io::{AsyncRead, AsyncWrite},
+    net::TcpStream,
+};
+use xmpp_parsers::{jid::Jid, ns};
+
+use crate::{
+    connect::{ServerConnector, ServerConnectorError, Tcp},
+    error::{Error, ProtocolError},
+    xmpp_codec::Packet,
+    xmpp_stream::XMPPStream,
+    AsyncClient,
+};
+
+/// AsyncClient that connects over StartTls
+pub type StartTlsAsyncClient = AsyncClient<ServerConfig>;
+
+/// StartTLS XMPP server connection configuration
+#[derive(Clone, Debug)]
+pub enum ServerConfig {
+    /// Use SRV record to find server host
+    UseSrv,
+    #[allow(unused)]
+    /// Manually define server host and port
+    Manual {
+        /// Server host name
+        host: String,
+        /// Server port
+        port: u16,
+    },
+}
+
+impl ServerConnector for ServerConfig {
+    type Stream = TlsStream<TcpStream>;
+    async fn connect(&self, jid: &Jid, ns: &str) -> Result<XMPPStream<Self::Stream>, Error> {
+        // TCP connection
+        let tcp_stream = match self {
+            ServerConfig::UseSrv => {
+                Tcp::resolve_with_srv(jid.domain().as_str(), "_xmpp-client._tcp", 5222).await?
+            }
+            ServerConfig::Manual { host, port } => Tcp::resolve(host.as_str(), *port).await?,
+        };
+
+        // Unencryped XMPPStream
+        let xmpp_stream = XMPPStream::start(tcp_stream, jid.clone(), ns.to_owned()).await?;
+
+        if xmpp_stream.stream_features.can_starttls() {
+            // TlsStream
+            let tls_stream = starttls(xmpp_stream).await?;
+            // Encrypted XMPPStream
+            Ok(XMPPStream::start(tls_stream, jid.clone(), ns.to_owned()).await?)
+        } else {
+            return Err(crate::Error::Protocol(ProtocolError::NoTls).into());
+        }
+    }
+
+    fn channel_binding(
+        #[allow(unused_variables)] stream: &Self::Stream,
+    ) -> Result<sasl::common::ChannelBinding, Error> {
+        #[cfg(feature = "tls-native")]
+        {
+            log::warn!("tls-native doesn’t support channel binding, please use tls-rust if you want this feature!");
+            Ok(ChannelBinding::None)
+        }
+        #[cfg(all(feature = "tls-rust", not(feature = "tls-native")))]
+        {
+            let (_, connection) = stream.get_ref();
+            Ok(match connection.protocol_version() {
+                // TODO: Add support for TLS 1.2 and earlier.
+                Some(tokio_rustls::rustls::ProtocolVersion::TLSv1_3) => {
+                    let data = vec![0u8; 32];
+                    let data = connection
+                        .export_keying_material(data, b"EXPORTER-Channel-Binding", None)
+                        .map_err(|e| StartTlsError::Tls(e))?;
+                    ChannelBinding::TlsExporter(data)
+                }
+                _ => ChannelBinding::None,
+            })
+        }
+    }
+}
+
+#[cfg(feature = "tls-native")]
+async fn get_tls_stream<S: AsyncRead + AsyncWrite + Unpin>(
+    xmpp_stream: XMPPStream<S>,
+) -> Result<TlsStream<S>, Error> {
+    let domain = xmpp_stream.jid.domain().to_owned();
+    let stream = xmpp_stream.into_inner();
+    let tls_stream = TlsConnector::from(NativeTlsConnector::builder().build().unwrap())
+        .connect(&domain, stream)
+        .await
+        .map_err(|e| StartTlsError::Tls(e))?;
+    Ok(tls_stream)
+}
+
+#[cfg(all(feature = "tls-rust", not(feature = "tls-native")))]
+async fn get_tls_stream<S: AsyncRead + AsyncWrite + Unpin>(
+    xmpp_stream: XMPPStream<S>,
+) -> Result<TlsStream<S>, Error> {
+    let domain = xmpp_stream.jid.domain().to_string();
+    let domain = ServerName::try_from(domain).map_err(|e| StartTlsError::DnsNameError(e))?;
+    let stream = xmpp_stream.into_inner();
+    let root_store = RootCertStore {
+        roots: webpki_roots::TLS_SERVER_ROOTS.into(),
+    };
+    let config = ClientConfig::builder()
+        .with_root_certificates(root_store)
+        .with_no_client_auth();
+    let tls_stream = TlsConnector::from(Arc::new(config))
+        .connect(domain, stream)
+        .await
+        .map_err(|e| Error::from(crate::Error::Io(e)))?;
+    Ok(tls_stream)
+}
+
+/// Performs `<starttls/>` on an XMPPStream and returns a binary
+/// TlsStream.
+pub async fn starttls<S: AsyncRead + AsyncWrite + Unpin>(
+    mut xmpp_stream: XMPPStream<S>,
+) -> Result<TlsStream<S>, Error> {
+    let nonza = Element::builder("starttls", ns::TLS).build();
+    let packet = Packet::Stanza(nonza);
+    xmpp_stream.send(packet).await?;
+
+    loop {
+        match xmpp_stream.next().await {
+            Some(Ok(Packet::Stanza(ref stanza))) if stanza.name() == "proceed" => break,
+            Some(Ok(Packet::Text(_))) => {}
+            Some(Err(e)) => return Err(e.into()),
+            _ => {
+                return Err(crate::Error::Protocol(ProtocolError::NoTls).into());
+            }
+        }
+    }
+
+    get_tls_stream(xmpp_stream).await
+}
+
+/// StartTLS ServerConnector Error
+#[derive(Debug)]
+pub enum StartTlsError {
+    /// TLS error
+    Tls(TlsError),
+    #[cfg(all(feature = "tls-rust", not(feature = "tls-native")))]
+    /// DNS name parsing error
+    DnsNameError(InvalidDnsNameError),
+}
+
+impl ServerConnectorError for StartTlsError {}
+
+impl fmt::Display for StartTlsError {
+    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            Self::Tls(e) => write!(fmt, "TLS error: {}", e),
+            #[cfg(all(feature = "tls-rust", not(feature = "tls-native")))]
+            Self::DnsNameError(e) => write!(fmt, "DNS name error: {}", e),
+        }
+    }
+}
+
+impl StdError for StartTlsError {}
+
+impl From<TlsError> for StartTlsError {
+    fn from(e: TlsError) -> Self {
+        Self::Tls(e)
+    }
+}
+
+#[cfg(all(feature = "tls-rust", not(feature = "tls-native")))]
+impl From<InvalidDnsNameError> for StartTlsError {
+    fn from(e: InvalidDnsNameError) -> Self {
+        Self::DnsNameError(e)
+    }
+}