use std::io::{self, Read, Write};
use futures::{Poll, Future, Async};
use native_tls::{self, HandshakeError, Error, TlsConnector};
use tokio_io::{AsyncRead, AsyncWrite};
/// A wrapper around an underlying raw stream which implements the TLS or SSL
/// protocol.
///
/// A `TlsStream<S>` represents a handshake that has been completed successfully
/// and both the server and the client are ready for receiving and sending
/// data. Bytes read from a `TlsStream` are decrypted from `S` and bytes written
/// to a `TlsStream` are encrypted when passing through to `S`.
#[derive(Debug)]
pub struct TlsStream<S> {
inner: native_tls::TlsStream<S>,
}
/// Future returned from `TlsConnectorExt::connect_async` which will resolve
/// once the connection handshake has finished.
pub struct ConnectAsync<S> {
inner: MidHandshake<S>,
}
struct MidHandshake<S> {
inner: Option<Result<native_tls::TlsStream<S>, HandshakeError<S>>>,
}
/// Extension trait for the `TlsConnector` type in the `native_tls` crate.
pub trait TlsConnectorExt: sealed::Sealed {
/// Connects the provided stream with this connector, assuming the provided
/// domain.
///
/// This function will internally call `TlsConnector::connect` to connect
/// the stream and returns a future representing the resolution of the
/// connection operation. The returned future will resolve to either
/// `TlsStream<S>` or `Error` depending if it's successful or not.
///
/// This is typically used for clients who have already established, for
/// example, a TCP connection to a remote server. That stream is then
/// provided here to perform the client half of a connection to a
/// TLS-powered server.
///
/// # Compatibility notes
///
/// Note that this method currently requires `S: Read + Write` but it's
/// highly recommended to ensure that the object implements the `AsyncRead`
/// and `AsyncWrite` traits as well, otherwise this function will not work
/// properly.
fn connect_async<S>(&self, domain: &str, stream: S) -> ConnectAsync<S>
where S: Read + Write; // TODO: change to AsyncRead + AsyncWrite
}
mod sealed {
pub trait Sealed {}
}
impl<S: Read + Write> Read for TlsStream<S> {
fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
self.inner.read(buf)
}
}
impl<S: Read + Write> Write for TlsStream<S> {
fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
self.inner.write(buf)
}
fn flush(&mut self) -> io::Result<()> {
self.inner.flush()
}
}
impl<S: AsyncRead + AsyncWrite> AsyncRead for TlsStream<S> {
}
impl<S: AsyncRead + AsyncWrite> AsyncWrite for TlsStream<S> {
fn shutdown(&mut self) -> Poll<(), io::Error> {
try_nb!(self.inner.shutdown());
self.inner.get_mut().shutdown()
}
}
impl TlsConnectorExt for TlsConnector {
fn connect_async<S>(&self, domain: &str, stream: S) -> ConnectAsync<S>
where S: Read + Write,
{
ConnectAsync {
inner: MidHandshake {
inner: Some(self.connect(domain, stream)),
},
}
}
}
impl sealed::Sealed for TlsConnector {}
// TODO: change this to AsyncRead/AsyncWrite on next major version
impl<S: Read + Write> Future for ConnectAsync<S> {
type Item = TlsStream<S>;
type Error = Error;
fn poll(&mut self) -> Poll<TlsStream<S>, Error> {
self.inner.poll()
}
}
// TODO: change this to AsyncRead/AsyncWrite on next major version
impl<S: Read + Write> Future for MidHandshake<S> {
type Item = TlsStream<S>;
type Error = Error;
fn poll(&mut self) -> Poll<TlsStream<S>, Error> {
match self.inner.take().expect("cannot poll MidHandshake twice") {
Ok(stream) => Ok(TlsStream { inner: stream }.into()),
Err(HandshakeError::Failure(e)) => Err(e),
Err(HandshakeError::WouldBlock(s)) => {
match s.handshake() {
Ok(stream) => Ok(TlsStream { inner: stream }.into()),
Err(HandshakeError::Failure(e)) => Err(e),
Err(HandshakeError::WouldBlock(s)) => {
self.inner = Some(Err(HandshakeError::WouldBlock(s)));
Ok(Async::NotReady)
}
}
}
}
}
}