add async_rustls

This crate inherits from the `async-rustls` crate and replaces its
dependency on std with 'rust-std-stub' using the prelude.

Signed-off-by: Jiaqi Gao <[email protected]>

Cargo.toml

@@ -1,6 +1,7 @@
 [workspace]
 
 members = [
+    "src/async_rustls",
     "src/attestation",
     "src/crypto",
     "src/devices/pci",

src/async_rustls/Cargo.toml

@@ -0,0 +1,15 @@
+[package]
+name = "async_rustls"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+rust_std_stub = { path = "../std-support/rust-std-stub" }
+futures-io = { path = "../std-support/futures-io" }
+rustls = { path = "../../deps/rustls/rustls", default-features = false, features = ["no_std", "alloc"] }
+
+[features]
+dangerous_configuration = ["rustls/dangerous_configuration"]
+early-data = []

src/async_rustls/src/client.rs

@@ -0,0 +1,220 @@
+use super::*;
+use crate::common::IoSession;
+
+/// A wrapper around an underlying raw stream which implements the TLS or SSL
+/// protocol.
+#[derive(Debug)]
+pub struct TlsStream<IO> {
+    pub(crate) io: IO,
+    pub(crate) session: ClientConnection,
+    pub(crate) state: TlsState,
+
+    #[cfg(feature = "early-data")]
+    pub(crate) early_waker: Option<core::task::Waker>,
+}
+
+impl<IO> TlsStream<IO> {
+    #[inline]
+    pub fn get_ref(&self) -> (&IO, &ClientConnection) {
+        (&self.io, &self.session)
+    }
+
+    #[inline]
+    pub fn get_mut(&mut self) -> (&mut IO, &mut ClientConnection) {
+        (&mut self.io, &mut self.session)
+    }
+
+    #[inline]
+    pub fn into_inner(self) -> (IO, ClientConnection) {
+        (self.io, self.session)
+    }
+}
+
+impl<IO> IoSession for TlsStream<IO> {
+    type Io = IO;
+    type Session = ClientConnection;
+
+    #[inline]
+    fn skip_handshake(&self) -> bool {
+        self.state.is_early_data()
+    }
+
+    #[inline]
+    fn get_mut(&mut self) -> (&mut TlsState, &mut Self::Io, &mut Self::Session) {
+        (&mut self.state, &mut self.io, &mut self.session)
+    }
+
+    #[inline]
+    fn into_io(self) -> Self::Io {
+        self.io
+    }
+}
+
+impl<IO> AsyncRead for TlsStream<IO>
+where
+    IO: AsyncRead + AsyncWrite + Unpin,
+{
+    fn poll_read(
+        self: Pin<&mut Self>,
+        cx: &mut Context<'_>,
+        buf: &mut [u8],
+    ) -> Poll<io::Result<usize>> {
+        match self.state {
+            #[cfg(feature = "early-data")]
+            TlsState::EarlyData(..) => {
+                let this = self.get_mut();
+
+                // In the EarlyData state, we have not really established a Tls connection.
+                // Before writing data through `AsyncWrite` and completing the tls handshake,
+                // we ignore read readiness and return to pending.
+                //
+                // In order to avoid event loss,
+                // we need to register a waker and wake it up after tls is connected.
+                if this
+                    .early_waker
+                    .as_ref()
+                    .filter(|waker| cx.waker().will_wake(waker))
+                    .is_none()
+                {
+                    this.early_waker = Some(cx.waker().clone());
+                }
+
+                Poll::Pending
+            }
+            TlsState::Stream | TlsState::WriteShutdown => {
+                let this = self.get_mut();
+                let mut stream =
+                    Stream::new(&mut this.io, &mut this.session).set_eof(!this.state.readable());
+
+                match stream.as_mut_pin().poll_read(cx, buf) {
+                    Poll::Ready(Ok(n)) => {
+                        if n == 0 || stream.eof {
+                            this.state.shutdown_read();
+                        }
+
+                        Poll::Ready(Ok(n))
+                    }
+                    Poll::Ready(Err(err)) if err.kind() == io::ErrorKind::ConnectionAborted => {
+                        this.state.shutdown_read();
+                        Poll::Ready(Err(err))
+                    }
+                    output => output,
+                }
+            }
+            TlsState::ReadShutdown | TlsState::FullyShutdown => Poll::Ready(Ok(0)),
+        }
+    }
+}
+
+impl<IO> AsyncWrite for TlsStream<IO>
+where
+    IO: AsyncRead + AsyncWrite + Unpin,
+{
+    /// Note: that it does not guarantee the final data to be sent.
+    /// To be cautious, you must manually call `flush`.
+    fn poll_write(
+        self: Pin<&mut Self>,
+        cx: &mut Context<'_>,
+        buf: &[u8],
+    ) -> Poll<io::Result<usize>> {
+        let this = self.get_mut();
+        let mut stream =
+            Stream::new(&mut this.io, &mut this.session).set_eof(!this.state.readable());
+
+        #[allow(clippy::match_single_binding)]
+        match this.state {
+            #[cfg(feature = "early-data")]
+            TlsState::EarlyData(ref mut pos, ref mut data) => {
+                use rust_std_stub::io::Write;
+
+                // write early data
+                if let Some(mut early_data) = stream.session.early_data() {
+                    let len = match early_data.write(buf) {
+                        Ok(n) => n,
+                        Err(ref err) if err.kind() == io::ErrorKind::WouldBlock => {
+                            return Poll::Pending
+                        }
+                        Err(err) => return Poll::Ready(Err(err)),
+                    };
+                    if len != 0 {
+                        data.extend_from_slice(&buf[..len]);
+                        return Poll::Ready(Ok(len));
+                    }
+                }
+
+                // complete handshake
+                while stream.session.is_handshaking() {
+                    ready!(stream.handshake(cx))?;
+                }
+
+                // write early data (fallback)
+                if !stream.session.is_early_data_accepted() {
+                    while *pos < data.len() {
+                        let len = ready!(stream.as_mut_pin().poll_write(cx, &data[*pos..]))?;
+                        *pos += len;
+                    }
+                }
+
+                // end
+                this.state = TlsState::Stream;
+
+                if let Some(waker) = this.early_waker.take() {
+                    waker.wake();
+                }
+
+                stream.as_mut_pin().poll_write(cx, buf)
+            }
+            _ => stream.as_mut_pin().poll_write(cx, buf),
+        }
+    }
+
+    fn poll_flush(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<io::Result<()>> {
+        let this = self.get_mut();
+        let mut stream =
+            Stream::new(&mut this.io, &mut this.session).set_eof(!this.state.readable());
+
+        #[cfg(feature = "early-data")]
+        {
+            if let TlsState::EarlyData(ref mut pos, ref mut data) = this.state {
+                // complete handshake
+                while stream.session.is_handshaking() {
+                    ready!(stream.handshake(cx))?;
+                }
+
+                // write early data (fallback)
+                if !stream.session.is_early_data_accepted() {
+                    while *pos < data.len() {
+                        let len = ready!(stream.as_mut_pin().poll_write(cx, &data[*pos..]))?;
+                        *pos += len;
+                    }
+                }
+
+                this.state = TlsState::Stream;
+
+                if let Some(waker) = this.early_waker.take() {
+                    waker.wake();
+                }
+            }
+        }
+
+        stream.as_mut_pin().poll_flush(cx)
+    }
+
+    fn poll_close(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<io::Result<()>> {
+        // complete handshake
+        #[cfg(feature = "early-data")]
+        if matches!(self.state, TlsState::EarlyData(..)) {
+            ready!(self.as_mut().poll_flush(cx))?;
+        }
+
+        if self.state.writeable() {
+            self.session.send_close_notify();
+            self.state.shutdown_write();
+        }
+
+        let this = self.get_mut();
+        let mut stream =
+            Stream::new(&mut this.io, &mut this.session).set_eof(!this.state.readable());
+        stream.as_mut_pin().poll_close(cx)
+    }
+}

src/async_rustls/src/common/handshake.rs

@@ -0,0 +1,70 @@
+use crate::common::{Stream, TlsState};
+use core::future::Future;
+use core::ops::{Deref, DerefMut};
+use core::pin::Pin;
+use core::task::{Context, Poll};
+use futures_io::{AsyncRead, AsyncWrite};
+use rust_std_stub::{io, mem};
+use rustls::{ConnectionCommon, SideData};
+
+pub(crate) trait IoSession {
+    type Io;
+    type Session;
+
+    fn skip_handshake(&self) -> bool;
+    fn get_mut(&mut self) -> (&mut TlsState, &mut Self::Io, &mut Self::Session);
+    fn into_io(self) -> Self::Io;
+}
+
+pub(crate) enum MidHandshake<IS: IoSession> {
+    Handshaking(IS),
+    End,
+    Error { io: IS::Io, error: io::Error },
+}
+
+impl<IS, SD> Future for MidHandshake<IS>
+where
+    IS: IoSession + Unpin,
+    IS::Io: AsyncRead + AsyncWrite + Unpin,
+    IS::Session: DerefMut + Deref<Target = ConnectionCommon<SD>> + Unpin,
+    SD: SideData,
+{
+    type Output = Result<IS, (io::Error, IS::Io)>;
+
+    fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
+        let this = self.get_mut();
+
+        let mut stream = match mem::replace(this, MidHandshake::End) {
+            MidHandshake::Handshaking(stream) => stream,
+            // Starting the handshake returned an error; fail the future immediately.
+            MidHandshake::Error { io, error } => return Poll::Ready(Err((error, io))),
+            _ => panic!("unexpected polling after handshake"),
+        };
+
+        if !stream.skip_handshake() {
+            let (state, io, session) = stream.get_mut();
+            let mut tls_stream = Stream::new(io, session).set_eof(!state.readable());
+
+            macro_rules! try_poll {
+                ( $e:expr ) => {
+                    match $e {
+                        Poll::Ready(Ok(_)) => (),
+                        Poll::Ready(Err(err)) => return Poll::Ready(Err((err, stream.into_io()))),
+                        Poll::Pending => {
+                            *this = MidHandshake::Handshaking(stream);
+                            return Poll::Pending;
+                        }
+                    }
+                };
+            }
+
+            while tls_stream.session.is_handshaking() {
+                try_poll!(tls_stream.handshake(cx));
+            }
+
+            try_poll!(Pin::new(&mut tls_stream).poll_flush(cx));
+        }
+
+        Poll::Ready(Ok(stream))
+    }
+}