reth_ecies/
stream.rs

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1//! The ECIES Stream implementation which wraps over [`AsyncRead`] and [`AsyncWrite`].
2
3use crate::{
4    codec::ECIESCodec, error::ECIESErrorImpl, ECIESError, EgressECIESValue, IngressECIESValue,
5};
6use alloy_primitives::{
7    bytes::{Bytes, BytesMut},
8    B512 as PeerId,
9};
10use futures::{ready, Sink, SinkExt};
11use secp256k1::SecretKey;
12use std::{
13    fmt::Debug,
14    io,
15    pin::Pin,
16    task::{Context, Poll},
17    time::Duration,
18};
19use tokio::{
20    io::{AsyncRead, AsyncWrite},
21    time::timeout,
22};
23use tokio_stream::{Stream, StreamExt};
24use tokio_util::codec::{Decoder, Framed};
25use tracing::{instrument, trace};
26
27const HANDSHAKE_TIMEOUT: Duration = Duration::from_secs(10);
28
29/// `ECIES` stream over TCP exchanging raw bytes
30#[derive(Debug)]
31#[pin_project::pin_project]
32pub struct ECIESStream<Io> {
33    #[pin]
34    stream: Framed<Io, ECIESCodec>,
35    remote_id: PeerId,
36}
37
38impl<Io> ECIESStream<Io>
39where
40    Io: AsyncRead + AsyncWrite + Unpin,
41{
42    /// Connect to an `ECIES` server
43    #[instrument(skip(transport, secret_key))]
44    pub async fn connect(
45        transport: Io,
46        secret_key: SecretKey,
47        remote_id: PeerId,
48    ) -> Result<Self, ECIESError> {
49        Self::connect_with_timeout(transport, secret_key, remote_id, HANDSHAKE_TIMEOUT).await
50    }
51
52    /// Wrapper around `connect_no_timeout` which enforces a timeout.
53    pub async fn connect_with_timeout(
54        transport: Io,
55        secret_key: SecretKey,
56        remote_id: PeerId,
57        timeout_limit: Duration,
58    ) -> Result<Self, ECIESError> {
59        timeout(timeout_limit, Self::connect_without_timeout(transport, secret_key, remote_id))
60            .await
61            .map_err(|_| ECIESError::from(ECIESErrorImpl::StreamTimeout))?
62    }
63
64    /// Connect to an `ECIES` server with no timeout.
65    pub async fn connect_without_timeout(
66        transport: Io,
67        secret_key: SecretKey,
68        remote_id: PeerId,
69    ) -> Result<Self, ECIESError> {
70        let ecies = ECIESCodec::new_client(secret_key, remote_id)
71            .map_err(|_| io::Error::other("invalid handshake"))?;
72
73        let mut transport = ecies.framed(transport);
74
75        trace!("sending ecies auth ...");
76        transport.send(EgressECIESValue::Auth).await?;
77
78        trace!("waiting for ecies ack ...");
79
80        let msg = transport.try_next().await?;
81
82        // `Framed` returns `None` if the underlying stream is no longer readable, and the codec is
83        // unable to decode another message from the (partially filled) buffer. This usually happens
84        // if the remote drops the TcpStream.
85        let msg = msg.ok_or(ECIESErrorImpl::UnreadableStream)?;
86
87        trace!("parsing ecies ack ...");
88        if matches!(msg, IngressECIESValue::Ack) {
89            Ok(Self { stream: transport, remote_id })
90        } else {
91            Err(ECIESErrorImpl::InvalidHandshake {
92                expected: IngressECIESValue::Ack,
93                msg: Some(msg),
94            }
95            .into())
96        }
97    }
98
99    /// Listen on a just connected ECIES client
100    pub async fn incoming(transport: Io, secret_key: SecretKey) -> Result<Self, ECIESError> {
101        let ecies = ECIESCodec::new_server(secret_key)?;
102
103        trace!("incoming ecies stream");
104        let mut transport = ecies.framed(transport);
105        let msg = transport.try_next().await?;
106
107        trace!("receiving ecies auth");
108        let remote_id = match &msg {
109            Some(IngressECIESValue::AuthReceive(remote_id)) => *remote_id,
110            _ => {
111                return Err(ECIESErrorImpl::InvalidHandshake {
112                    expected: IngressECIESValue::AuthReceive(Default::default()),
113                    msg,
114                }
115                .into())
116            }
117        };
118
119        trace!("sending ecies ack");
120        transport.send(EgressECIESValue::Ack).await?;
121
122        Ok(Self { stream: transport, remote_id })
123    }
124
125    /// Get the remote id
126    pub const fn remote_id(&self) -> PeerId {
127        self.remote_id
128    }
129}
130
131impl<Io> Stream for ECIESStream<Io>
132where
133    Io: AsyncRead + Unpin,
134{
135    type Item = Result<BytesMut, io::Error>;
136
137    fn poll_next(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
138        match ready!(self.project().stream.poll_next(cx)) {
139            Some(Ok(IngressECIESValue::Message(body))) => Poll::Ready(Some(Ok(body))),
140            Some(other) => Poll::Ready(Some(Err(io::Error::other(format!(
141                "ECIES stream protocol error: expected message, received {other:?}"
142            ))))),
143            None => Poll::Ready(None),
144        }
145    }
146}
147
148impl<Io> Sink<Bytes> for ECIESStream<Io>
149where
150    Io: AsyncWrite + Unpin,
151{
152    type Error = io::Error;
153
154    fn poll_ready(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
155        self.project().stream.poll_ready(cx)
156    }
157
158    fn start_send(self: Pin<&mut Self>, item: Bytes) -> Result<(), Self::Error> {
159        self.project().stream.start_send(EgressECIESValue::Message(item))?;
160        Ok(())
161    }
162
163    fn poll_flush(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
164        self.project().stream.poll_flush(cx)
165    }
166
167    fn poll_close(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
168        self.project().stream.poll_close(cx)
169    }
170}
171
172#[cfg(test)]
173mod tests {
174    use super::*;
175    use reth_network_peers::pk2id;
176    use secp256k1::SECP256K1;
177    use tokio::net::{TcpListener, TcpStream};
178
179    #[tokio::test]
180    async fn can_write_and_read() {
181        let listener = TcpListener::bind("127.0.0.1:0").await.unwrap();
182        let addr = listener.local_addr().unwrap();
183        let server_key = SecretKey::new(&mut rand_08::thread_rng());
184
185        let handle = tokio::spawn(async move {
186            // roughly based off of the design of tokio::net::TcpListener
187            let (incoming, _) = listener.accept().await.unwrap();
188            let mut stream = ECIESStream::incoming(incoming, server_key).await.unwrap();
189
190            // use the stream to get the next message
191            let message = stream.next().await.unwrap().unwrap();
192            assert_eq!(message, Bytes::from("hello"));
193        });
194
195        // create the server pubkey
196        let server_id = pk2id(&server_key.public_key(SECP256K1));
197
198        let client_key = SecretKey::new(&mut rand_08::thread_rng());
199        let outgoing = TcpStream::connect(addr).await.unwrap();
200        let mut client_stream =
201            ECIESStream::connect(outgoing, client_key, server_id).await.unwrap();
202        client_stream.send(Bytes::from("hello")).await.unwrap();
203
204        // make sure the server receives the message and asserts before ending the test
205        handle.await.unwrap();
206    }
207
208    #[tokio::test]
209    async fn connection_should_timeout() {
210        let listener = TcpListener::bind("127.0.0.1:0").await.unwrap();
211        let addr = listener.local_addr().unwrap();
212        let server_key = SecretKey::new(&mut rand_08::thread_rng());
213
214        let _handle = tokio::spawn(async move {
215            // Delay accepting the connection for longer than the client's timeout period
216            tokio::time::sleep(Duration::from_secs(11)).await;
217            let (incoming, _) = listener.accept().await.unwrap();
218            let mut stream = ECIESStream::incoming(incoming, server_key).await.unwrap();
219
220            // use the stream to get the next message
221            let message = stream.next().await.unwrap().unwrap();
222            assert_eq!(message, Bytes::from("hello"));
223        });
224
225        // create the server pubkey
226        let server_id = pk2id(&server_key.public_key(SECP256K1));
227
228        let client_key = SecretKey::new(&mut rand_08::thread_rng());
229        let outgoing = TcpStream::connect(addr).await.unwrap();
230
231        // Attempt to connect, expecting a timeout due to the server's delayed response
232        let connect_result = ECIESStream::connect_with_timeout(
233            outgoing,
234            client_key,
235            server_id,
236            Duration::from_secs(1),
237        )
238        .await;
239
240        // Assert that a timeout error occurred
241        assert!(
242            matches!(connect_result, Err(e) if e.to_string() == ECIESErrorImpl::StreamTimeout.to_string())
243        );
244    }
245}
reth_ecies/stream.rs

reth_ecies/
stream.rs
