libp2p_plaintext/
handshake.rs

1// Copyright 2019 Parity Technologies (UK) Ltd.
2//
3// Permission is hereby granted, free of charge, to any person obtaining a
4// copy of this software and associated documentation files (the "Software"),
5// to deal in the Software without restriction, including without limitation
6// the rights to use, copy, modify, merge, publish, distribute, sublicense,
7// and/or sell copies of the Software, and to permit persons to whom the
8// Software is furnished to do so, subject to the following conditions:
9//
10// The above copyright notice and this permission notice shall be included in
11// all copies or substantial portions of the Software.
12//
13// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
14// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
15// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
16// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
17// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
18// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
19// DEALINGS IN THE SOFTWARE.
20
21use std::io::{Error as IoError, ErrorKind as IoErrorKind};
22
23use asynchronous_codec::{Framed, FramedParts};
24use bytes::Bytes;
25use futures::prelude::*;
26use libp2p_identity::{PeerId, PublicKey};
27
28use crate::{
29    error::{DecodeError, Error},
30    proto::Exchange,
31    Config,
32};
33
34pub(crate) async fn handshake<S>(socket: S, config: Config) -> Result<(S, PublicKey, Bytes), Error>
35where
36    S: AsyncRead + AsyncWrite + Send + Unpin,
37{
38    // The handshake messages all start with a variable-length integer indicating the size.
39    let mut framed_socket = Framed::new(socket, quick_protobuf_codec::Codec::<Exchange>::new(100));
40
41    tracing::trace!("sending exchange to remote");
42    framed_socket
43        .send(Exchange {
44            id: Some(config.local_public_key.to_peer_id().to_bytes()),
45            pubkey: Some(config.local_public_key.encode_protobuf()),
46        })
47        .await
48        .map_err(DecodeError)?;
49
50    tracing::trace!("receiving the remote's exchange");
51    let public_key = match framed_socket
52        .next()
53        .await
54        .transpose()
55        .map_err(DecodeError)?
56    {
57        Some(remote) => {
58            let public_key = PublicKey::try_decode_protobuf(&remote.pubkey.unwrap_or_default())?;
59            let peer_id = PeerId::from_bytes(&remote.id.unwrap_or_default())?;
60
61            if peer_id != public_key.to_peer_id() {
62                return Err(Error::PeerIdMismatch);
63            }
64
65            public_key
66        }
67        None => {
68            tracing::debug!("unexpected eof while waiting for remote's exchange");
69            let err = IoError::new(IoErrorKind::BrokenPipe, "unexpected eof");
70            return Err(err.into());
71        }
72    };
73
74    tracing::trace!(?public_key, "received exchange from remote");
75
76    let FramedParts {
77        io,
78        read_buffer,
79        write_buffer,
80        ..
81    } = framed_socket.into_parts();
82    assert!(write_buffer.is_empty());
83    Ok((io, public_key, read_buffer.freeze()))
84}
libp2p_plaintext/handshake.rs

libp2p_plaintext/
handshake.rs
