Implement SOCKS5 server: local proxy forwarding through SSH channels

Convert socks5.rs to directory module with protocol parsing and server
implementation. Socks5Server binds to configurable address (default
127.0.0.1:1080), handles SOCKS5 handshake (no-auth), parses IPv4/IPv6/domain
addresses, and proxies bidirectionally via SSH direct_tcpip channels.
Domain names sent unresolved (SOCKS5h) to prevent DNS leaks (ADR-006).
No logging of request targets per privacy requirements.

crates/wraith-core/Cargo.toml

@@ -10,7 +10,7 @@ name = "wraith_core"
 default = []
 tls = ["dep:tokio-rustls", "dep:rustls", "dep:rustls-pki-types", "dep:webpki-roots"]
 iroh = ["dep:iroh", "dep:url"]
-acme = ["dep:rustls-acme", "dep:futures", "tls"]
+acme = ["dep:rustls-acme", "tls"]
 testutil = []
 transport-traits = []
 
@@ -25,7 +25,6 @@ tokio-rustls = { version = "0.26", optional = true }
 rustls = { version = "0.23", optional = true, features = ["aws_lc_rs"] }
 rustls-pki-types = { version = "1", optional = true }
 rustls-acme = { version = "0.12", optional = true }
-futures = { version = "0.3", optional = true }
 webpki-roots = { version = "0.26", optional = true }
 iroh = { version = "0.34", optional = true }
 url = { version = "2", optional = true }

crates/wraith-core/src/socks5/mod.rs

@@ -0,0 +1,490 @@
+mod protocol;
+
+use std::net::SocketAddr;
+use std::sync::Arc;
+
+use tokio::io::{AsyncRead, AsyncWrite, AsyncWriteExt};
+use tokio::net::TcpListener;
+use tokio::sync::Mutex;
+use tracing::debug;
+
+use protocol::{Socks5Reply, Socks5Request, Socks5VersionMethod};
+
+pub use protocol::Socks5Address;
+
+const DEFAULT_SOCKS5_ADDR: &str = "127.0.0.1:1080";
+
+pub trait ChannelOpener: Send + Sync + 'static {
+    type Stream: AsyncRead + AsyncWrite + Unpin + Send + 'static;
+
+    fn open_channel(
+        &self,
+        host: String,
+        port: u16,
+    ) -> impl std::future::Future<Output = Result<Self::Stream, ChannelOpenError>> + Send;
+}
+
+#[derive(Debug, thiserror::Error)]
+pub enum ChannelOpenError {
+    #[error("session closed")]
+    SessionClosed,
+    #[error("channel open failed")]
+    ChannelOpenFailed,
+    #[error("connection refused")]
+    ConnectionRefused,
+}
+
+pub struct Socks5Server<C: ChannelOpener> {
+    listen_addr: SocketAddr,
+    channel_opener: Arc<C>,
+}
+
+impl<C: ChannelOpener> Socks5Server<C> {
+    pub fn new(channel_opener: C) -> Self {
+        Self::with_addr(channel_opener, DEFAULT_SOCKS5_ADDR)
+    }
+
+    pub fn with_addr(channel_opener: C, addr: &str) -> Self {
+        let listen_addr: SocketAddr = addr
+            .parse()
+            .expect("invalid SOCKS5 listen address");
+        Self {
+            listen_addr,
+            channel_opener: Arc::new(channel_opener),
+        }
+    }
+
+    pub fn listen_addr(&self) -> SocketAddr {
+        self.listen_addr
+    }
+
+    pub async fn run(self) -> Result<(), std::io::Error> {
+        let listener = TcpListener::bind(self.listen_addr).await?;
+        debug!("socks5 server listening on {}", self.listen_addr);
+        loop {
+            let (socket, _peer) = listener.accept().await?;
+            let opener = Arc::clone(&self.channel_opener);
+            tokio::spawn(async move {
+                if let Err(e) = handle_socks5_connection(socket, opener).await {
+                    debug!("socks5 connection error: {e}");
+                }
+            });
+        }
+    }
+}
+
+async fn handle_socks5_connection<S, C>(
+    mut socket: S,
+    opener: Arc<C>,
+) -> Result<(), Socks5Error>
+where
+    S: AsyncRead + AsyncWrite + Unpin,
+    C: ChannelOpener,
+{
+    let vm = Socks5VersionMethod::read_from(&mut socket).await?;
+    if vm.version != 0x05 {
+        return Err(Socks5Error::InvalidVersion(vm.version));
+    }
+    if !vm.methods.contains(&0x00) {
+        let reply = [0x05, 0xFF];
+        socket.write_all(&reply).await?;
+        socket.shutdown().await?;
+        return Err(Socks5Error::NoAcceptableAuth);
+    }
+    let reply = [0x05, 0x00];
+    socket.write_all(&reply).await?;
+
+    let request = Socks5Request::read_from(&mut socket).await?;
+    if request.version != 0x05 {
+        return Err(Socks5Error::InvalidVersion(request.version));
+    }
+    if request.command != 0x01 {
+        send_error_reply(&mut socket, Socks5Reply::command_not_supported()).await?;
+        return Err(Socks5Error::UnsupportedCommand(request.command));
+    }
+
+    let (host, port) = match &request.address {
+        Socks5Address::Ipv4(addr) => (addr.to_string(), request.port),
+        Socks5Address::Ipv6(addr) => (addr.to_string(), request.port),
+        Socks5Address::Domain(name) => (name.clone(), request.port),
+    };
+
+    match opener.open_channel(host, port).await {
+        Ok(mut ssh_stream) => {
+            let bind_addr = Socks5Address::Ipv4(std::net::Ipv4Addr::UNSPECIFIED);
+            let reply = Socks5Reply::success(bind_addr, 0);
+            reply.write_to(&mut socket).await?;
+            tokio::io::copy_bidirectional(&mut socket, &mut ssh_stream).await?;
+            Ok(())
+        }
+        Err(_) => {
+            send_error_reply(&mut socket, Socks5Reply::connection_refused()).await?;
+            Err(Socks5Error::ChannelOpenFailed)
+        }
+    }
+}
+
+async fn send_error_reply<S: AsyncRead + AsyncWrite + Unpin>(
+    socket: &mut S,
+    reply: Socks5Reply,
+) -> Result<(), Socks5Error> {
+    reply.write_to(socket).await?;
+    let _ = socket.shutdown().await;
+    Ok(())
+}
+
+#[derive(Debug, thiserror::Error)]
+pub enum Socks5Error {
+    #[error("invalid SOCKS version: {0}")]
+    InvalidVersion(u8),
+    #[error("no acceptable auth method")]
+    NoAcceptableAuth,
+    #[error("unsupported command: {0}")]
+    UnsupportedCommand(u8),
+    #[error("channel open failed")]
+    ChannelOpenFailed,
+    #[error("io error")]
+    Io(#[from] std::io::Error),
+}
+
+pub struct HandleChannelOpener<H: russh::client::Handler> {
+    handle: Arc<Mutex<russh::client::Handle<H>>>,
+}
+
+impl<H: russh::client::Handler> HandleChannelOpener<H> {
+    pub fn new(handle: russh::client::Handle<H>) -> Self {
+        Self {
+            handle: Arc::new(Mutex::new(handle)),
+        }
+    }
+
+    pub fn from_arc(handle: Arc<Mutex<russh::client::Handle<H>>>) -> Self {
+        Self { handle }
+    }
+}
+
+impl<H: russh::client::Handler + Send + Sync + 'static> ChannelOpener for HandleChannelOpener<H> {
+    type Stream = russh::ChannelStream<russh::client::Msg>;
+
+    async fn open_channel(&self, host: String, port: u16) -> Result<Self::Stream, ChannelOpenError> {
+        let handle = self.handle.lock().await;
+        if handle.is_closed() {
+            return Err(ChannelOpenError::SessionClosed);
+        }
+        let channel = handle
+            .channel_open_direct_tcpip(host, port as u32, "127.0.0.1", 0)
+            .await
+            .map_err(|_| ChannelOpenError::ChannelOpenFailed)?;
+        Ok(channel.into_stream())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use tokio::io::{duplex, AsyncReadExt, AsyncWriteExt, DuplexStream};
+
+    struct MockChannelOpener {
+        fail: bool,
+    }
+
+    impl ChannelOpener for MockChannelOpener {
+        type Stream = DuplexStream;
+
+        async fn open_channel(
+            &self,
+            _host: String,
+            _port: u16,
+        ) -> Result<Self::Stream, ChannelOpenError> {
+            if self.fail {
+                Err(ChannelOpenError::ChannelOpenFailed)
+            } else {
+                let (client, _server) = duplex(4096);
+                Ok(client)
+            }
+        }
+    }
+
+    fn build_socks5_greeting(methods: &[u8]) -> Vec<u8> {
+        let mut buf = vec![0x05, methods.len() as u8];
+        buf.extend_from_slice(methods);
+        buf
+    }
+
+    fn build_socks5_connect_ipv4(addr: [u8; 4], port: u16) -> Vec<u8> {
+        let mut buf = vec![0x05, 0x01, 0x00, 0x01];
+        buf.extend_from_slice(&addr);
+        buf.extend_from_slice(&port.to_be_bytes());
+        buf
+    }
+
+    fn build_socks5_connect_domain(domain: &str, port: u16) -> Vec<u8> {
+        let mut buf = vec![0x05, 0x01, 0x00, 0x03];
+        buf.push(domain.len() as u8);
+        buf.extend_from_slice(domain.as_bytes());
+        buf.extend_from_slice(&port.to_be_bytes());
+        buf
+    }
+
+    fn build_socks5_connect_ipv6(addr: [u8; 16], port: u16) -> Vec<u8> {
+        let mut buf = vec![0x05, 0x01, 0x00, 0x04];
+        buf.extend_from_slice(&addr);
+        buf.extend_from_slice(&port.to_be_bytes());
+        buf
+    }
+
+    async fn do_handshake(client: &mut DuplexStream) -> [u8; 2] {
+        client.write_all(&build_socks5_greeting(&[0x00])).await.unwrap();
+        client.flush().await.unwrap();
+        let mut resp = [0u8; 2];
+        client.read_exact(&mut resp).await.unwrap();
+        resp
+    }
+
+    async fn do_connect_ipv4(client: &mut DuplexStream, addr: [u8; 4], port: u16) -> Vec<u8> {
+        client
+            .write_all(&build_socks5_connect_ipv4(addr, port))
+            .await
+            .unwrap();
+        client.flush().await.unwrap();
+        let mut reply_buf = [0u8; 10];
+        client.read_exact(&mut reply_buf).await.unwrap();
+        reply_buf.to_vec()
+    }
+
+    #[tokio::test]
+    async fn handshake_no_auth_method() {
+        let (mut client, server) = duplex(4096);
+        let opener = MockChannelOpener { fail: false };
+
+        let server_handle = tokio::spawn(async move {
+            handle_socks5_connection(server, Arc::new(opener)).await
+        });
+
+        let resp = do_handshake(&mut client).await;
+        assert_eq!(resp, [0x05, 0x00]);
+
+        let reply_buf = do_connect_ipv4(&mut client, [127, 0, 0, 1], 80).await;
+        assert_eq!(reply_buf[0], 0x05);
+        assert_eq!(reply_buf[1], 0x00);
+
+        drop(client);
+        let _ = server_handle.await;
+    }
+
+    #[tokio::test]
+    async fn handshake_rejects_no_acceptable_method() {
+        let (mut client, server) = duplex(4096);
+        let opener = MockChannelOpener { fail: false };
+
+        let server_handle = tokio::spawn(async move {
+            handle_socks5_connection(server, Arc::new(opener)).await
+        });
+
+        client
+            .write_all(&build_socks5_greeting(&[0x02]))
+            .await
+            .unwrap();
+        client.flush().await.unwrap();
+
+        let mut resp = [0u8; 2];
+        client.read_exact(&mut resp).await.unwrap();
+        assert_eq!(resp, [0x05, 0xFF]);
+
+        drop(client);
+        let result = server_handle.await.unwrap();
+        assert!(result.is_err());
+        assert!(matches!(
+            result.unwrap_err(),
+            Socks5Error::NoAcceptableAuth
+        ));
+    }
+
+    #[tokio::test]
+    async fn address_type_ipv4() {
+        let (mut client, server) = duplex(4096);
+        let opener = MockChannelOpener { fail: false };
+
+        let server_handle = tokio::spawn(async move {
+            handle_socks5_connection(server, Arc::new(opener)).await
+        });
+
+        do_handshake(&mut client).await;
+        let reply_buf = do_connect_ipv4(&mut client, [10, 0, 0, 1], 443).await;
+        assert_eq!(reply_buf[1], 0x00);
+
+        drop(client);
+        let _ = server_handle.await;
+    }
+
+    #[tokio::test]
+    async fn address_type_domain() {
+        let (mut client, server) = duplex(4096);
+        let opener = MockChannelOpener { fail: false };
+
+        let server_handle = tokio::spawn(async move {
+            handle_socks5_connection(server, Arc::new(opener)).await
+        });
+
+        do_handshake(&mut client).await;
+
+        client
+            .write_all(&build_socks5_connect_domain("example.com", 443))
+            .await
+            .unwrap();
+        client.flush().await.unwrap();
+
+        let mut reply_buf = [0u8; 10];
+        client.read_exact(&mut reply_buf).await.unwrap();
+        assert_eq!(reply_buf[1], 0x00);
+
+        drop(client);
+        let _ = server_handle.await;
+    }
+
+    #[tokio::test]
+    async fn address_type_ipv6() {
+        let (mut client, server) = duplex(4096);
+        let opener = MockChannelOpener { fail: false };
+
+        let server_handle = tokio::spawn(async move {
+            handle_socks5_connection(server, Arc::new(opener)).await
+        });
+
+        do_handshake(&mut client).await;
+
+        let ipv6_addr = [0x20, 0x01, 0x0d, 0xb8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1];
+        client
+            .write_all(&build_socks5_connect_ipv6(ipv6_addr, 443))
+            .await
+            .unwrap();
+        client.flush().await.unwrap();
+
+        let mut reply_buf = [0u8; 10];
+        client.read_exact(&mut reply_buf).await.unwrap();
+        assert_eq!(reply_buf[0], 0x05);
+        assert_eq!(reply_buf[1], 0x00);
+
+        drop(client);
+        let _ = server_handle.await;
+    }
+
+    #[tokio::test]
+    async fn channel_open_failure_returns_socks5_error() {
+        let (mut client, server) = duplex(4096);
+        let opener = MockChannelOpener { fail: true };
+
+        let server_handle = tokio::spawn(async move {
+            handle_socks5_connection(server, Arc::new(opener)).await
+        });
+
+        do_handshake(&mut client).await;
+        let reply_buf = do_connect_ipv4(&mut client, [10, 0, 0, 1], 80).await;
+        assert_eq!(reply_buf[0], 0x05);
+        assert_eq!(reply_buf[1], 0x05);
+
+        drop(client);
+        let _ = server_handle.await;
+    }
+
+    #[tokio::test]
+    async fn unsupported_command_returns_error() {
+        let (mut client, server) = duplex(4096);
+        let opener = MockChannelOpener { fail: false };
+
+        let server_handle = tokio::spawn(async move {
+            handle_socks5_connection(server, Arc::new(opener)).await
+        });
+
+        do_handshake(&mut client).await;
+
+        let mut bind_req = vec![0x05, 0x02, 0x00, 0x01];
+        bind_req.extend_from_slice(&[127, 0, 0, 1]);
+        bind_req.extend_from_slice(&80u16.to_be_bytes());
+        client.write_all(&bind_req).await.unwrap();
+        client.flush().await.unwrap();
+
+        let mut reply_buf = [0u8; 10];
+        client.read_exact(&mut reply_buf).await.unwrap();
+        assert_eq!(reply_buf[1], 0x07);
+
+        drop(client);
+        let _ = server_handle.await;
+    }
+
+    #[tokio::test]
+    async fn bidirectional_proxy_flow() {
+        let (mut client_sock, server_sock) = duplex(4096);
+        let (ssh_client, mut ssh_server) = duplex(4096);
+
+        let ssh_stream = Arc::new(Mutex::new(Some(ssh_client)));
+
+        struct ProxyOpener {
+            stream: Arc<Mutex<Option<DuplexStream>>>,
+        }
+
+        impl ChannelOpener for ProxyOpener {
+            type Stream = DuplexStream;
+
+            async fn open_channel(
+                &self,
+                _host: String,
+                _port: u16,
+            ) -> Result<Self::Stream, ChannelOpenError> {
+                self.stream
+                    .lock()
+                    .await
+                    .take()
+                    .ok_or(ChannelOpenError::ChannelOpenFailed)
+            }
+        }
+
+        let opener = ProxyOpener {
+            stream: Arc::clone(&ssh_stream),
+        };
+
+        let server_handle = tokio::spawn(async move {
+            handle_socks5_connection(server_sock, Arc::new(opener)).await
+        });
+
+        do_handshake(&mut client_sock).await;
+        let reply_buf = do_connect_ipv4(&mut client_sock, [127, 0, 0, 1], 80).await;
+        assert_eq!(reply_buf[1], 0x00);
+
+        let test_data = b"hello through tunnel";
+        client_sock.write_all(test_data).await.unwrap();
+        client_sock.flush().await.unwrap();
+
+        let mut received = vec![0u8; test_data.len()];
+        AsyncReadExt::read_exact(&mut ssh_server, &mut received)
+            .await
+            .unwrap();
+        assert_eq!(&received, test_data);
+
+        let echo_data = b"response from tunnel";
+        ssh_server.write_all(echo_data).await.unwrap();
+        ssh_server.flush().await.unwrap();
+
+        let mut received_back = vec![0u8; echo_data.len()];
+        client_sock.read_exact(&mut received_back).await.unwrap();
+        assert_eq!(&received_back, echo_data);
+
+        drop(client_sock);
+        drop(ssh_server);
+        let _ = server_handle.await;
+    }
+
+    #[tokio::test]
+    async fn default_listen_address() {
+        let opener = MockChannelOpener { fail: false };
+        let server = Socks5Server::new(opener);
+        assert_eq!(server.listen_addr(), "127.0.0.1:1080".parse().unwrap());
+    }
+
+    #[tokio::test]
+    async fn custom_listen_address() {
+        let opener = MockChannelOpener { fail: false };
+        let server = Socks5Server::with_addr(opener, "127.0.0.1:9050");
+        assert_eq!(server.listen_addr(), "127.0.0.1:9050".parse().unwrap());
+    }
+}

crates/wraith-core/src/socks5/protocol.rs

@@ -0,0 +1,304 @@
+use std::net::{Ipv4Addr, Ipv6Addr};
+
+use tokio::io::{AsyncRead, AsyncReadExt, AsyncWrite, AsyncWriteExt};
+
+#[derive(Debug, Clone, PartialEq)]
+pub enum Socks5Address {
+    Ipv4(Ipv4Addr),
+    Ipv6(Ipv6Addr),
+    Domain(String),
+}
+
+#[derive(Debug)]
+pub struct Socks5VersionMethod {
+    pub version: u8,
+    pub methods: Vec<u8>,
+}
+
+impl Socks5VersionMethod {
+    pub async fn read_from<R: AsyncRead + Unpin>(reader: &mut R) -> std::io::Result<Self> {
+        let version = reader.read_u8().await?;
+        let nmethods = reader.read_u8().await?;
+        let mut methods = vec![0u8; nmethods as usize];
+        reader.read_exact(&mut methods).await?;
+        Ok(Self { version, methods })
+    }
+}
+
+#[derive(Debug)]
+pub struct Socks5Request {
+    pub version: u8,
+    pub command: u8,
+    pub address: Socks5Address,
+    pub port: u16,
+}
+
+impl Socks5Request {
+    pub async fn read_from<R: AsyncRead + Unpin>(reader: &mut R) -> std::io::Result<Self> {
+        let version = reader.read_u8().await?;
+        let command = reader.read_u8().await?;
+        let _rsv = reader.read_u8().await?;
+        let atyp = reader.read_u8().await?;
+
+        let address = match atyp {
+            0x01 => {
+                let mut octets = [0u8; 4];
+                reader.read_exact(&mut octets).await?;
+                Socks5Address::Ipv4(Ipv4Addr::from(octets))
+            }
+            0x04 => {
+                let mut octets = [0u8; 16];
+                reader.read_exact(&mut octets).await?;
+                Socks5Address::Ipv6(Ipv6Addr::from(octets))
+            }
+            0x03 => {
+                let len = reader.read_u8().await?;
+                let mut domain = vec![0u8; len as usize];
+                reader.read_exact(&mut domain).await?;
+                Socks5Address::Domain(String::from_utf8_lossy(&domain).into_owned())
+            }
+            _ => {
+                return Err(std::io::Error::new(
+                    std::io::ErrorKind::InvalidData,
+                    format!("unsupported address type: {atyp}"),
+                ))
+            }
+        };
+
+        let port = reader.read_u16().await?;
+
+        Ok(Self {
+            version,
+            command,
+            address,
+            port,
+        })
+    }
+}
+
+#[derive(Debug)]
+pub struct Socks5Reply {
+    pub version: u8,
+    pub reply: u8,
+    pub address: Socks5Address,
+    pub port: u16,
+}
+
+impl Socks5Reply {
+    pub fn success(address: Socks5Address, port: u16) -> Self {
+        Self {
+            version: 0x05,
+            reply: 0x00,
+            address,
+            port,
+        }
+    }
+
+    pub fn connection_refused() -> Self {
+        Self {
+            version: 0x05,
+            reply: 0x05,
+            address: Socks5Address::Ipv4(Ipv4Addr::UNSPECIFIED),
+            port: 0,
+        }
+    }
+
+    pub fn command_not_supported() -> Self {
+        Self {
+            version: 0x05,
+            reply: 0x07,
+            address: Socks5Address::Ipv4(Ipv4Addr::UNSPECIFIED),
+            port: 0,
+        }
+    }
+
+    pub async fn write_to<W: AsyncWrite + Unpin>(&self, writer: &mut W) -> std::io::Result<()> {
+        writer.write_u8(self.version).await?;
+        writer.write_u8(self.reply).await?;
+        writer.write_u8(0x00).await?;
+        match &self.address {
+            Socks5Address::Ipv4(addr) => {
+                writer.write_u8(0x01).await?;
+                writer.write_all(&addr.octets()).await?;
+            }
+            Socks5Address::Ipv6(addr) => {
+                writer.write_u8(0x04).await?;
+                writer.write_all(&addr.octets()).await?;
+            }
+            Socks5Address::Domain(name) => {
+                writer.write_u8(0x03).await?;
+                writer.write_u8(name.len() as u8).await?;
+                writer.write_all(name.as_bytes()).await?;
+            }
+        }
+        writer.write_u16(self.port).await?;
+        writer.flush().await?;
+        Ok(())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::io::Cursor;
+
+    #[tokio::test]
+    async fn parse_version_method_no_auth() {
+        let data = [0x05, 0x01, 0x00];
+        let mut cursor = Cursor::new(&data[..]);
+        let vm = Socks5VersionMethod::read_from(&mut cursor).await.unwrap();
+        assert_eq!(vm.version, 0x05);
+        assert_eq!(vm.methods, vec![0x00]);
+    }
+
+    #[tokio::test]
+    async fn parse_version_method_multiple() {
+        let data = [0x05, 0x02, 0x00, 0x02];
+        let mut cursor = Cursor::new(&data[..]);
+        let vm = Socks5VersionMethod::read_from(&mut cursor).await.unwrap();
+        assert_eq!(vm.version, 0x05);
+        assert_eq!(vm.methods, vec![0x00, 0x02]);
+    }
+
+    #[tokio::test]
+    async fn parse_request_ipv4() {
+        let mut data = vec![0x05, 0x01, 0x00, 0x01];
+        data.extend_from_slice(&[10, 0, 0, 1]);
+        data.extend_from_slice(&443u16.to_be_bytes());
+        let mut cursor = Cursor::new(&data[..]);
+        let req = Socks5Request::read_from(&mut cursor).await.unwrap();
+        assert_eq!(req.version, 0x05);
+        assert_eq!(req.command, 0x01);
+        assert_eq!(
+            req.address,
+            Socks5Address::Ipv4(Ipv4Addr::new(10, 0, 0, 1))
+        );
+        assert_eq!(req.port, 443);
+    }
+
+    #[tokio::test]
+    async fn parse_request_ipv6() {
+        let mut data = vec![0x05, 0x01, 0x00, 0x04];
+        let octets: [u8; 16] = [0x20, 0x01, 0x0d, 0xb8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1];
+        data.extend_from_slice(&octets);
+        data.extend_from_slice(&443u16.to_be_bytes());
+        let mut cursor = Cursor::new(&data[..]);
+        let req = Socks5Request::read_from(&mut cursor).await.unwrap();
+        assert_eq!(req.version, 0x05);
+        assert_eq!(req.command, 0x01);
+        assert!(matches!(req.address, Socks5Address::Ipv6(_)));
+        assert_eq!(req.port, 443);
+    }
+
+    #[tokio::test]
+    async fn parse_request_domain() {
+        let domain = "example.com";
+        let mut data = vec![0x05, 0x01, 0x00, 0x03];
+        data.push(domain.len() as u8);
+        data.extend_from_slice(domain.as_bytes());
+        data.extend_from_slice(&443u16.to_be_bytes());
+        let mut cursor = Cursor::new(&data[..]);
+        let req = Socks5Request::read_from(&mut cursor).await.unwrap();
+        assert_eq!(req.version, 0x05);
+        assert_eq!(req.command, 0x01);
+        assert_eq!(req.address, Socks5Address::Domain("example.com".to_string()));
+        assert_eq!(req.port, 443);
+    }
+
+    #[tokio::test]
+    async fn parse_request_unsupported_address_type() {
+        let data = [0x05, 0x01, 0x00, 0x05];
+        let mut cursor = Cursor::new(&data[..]);
+        let result = Socks5Request::read_from(&mut cursor).await;
+        assert!(result.is_err());
+    }
+
+    #[tokio::test]
+    async fn reply_success_ipv4() {
+        let reply = Socks5Reply::success(Socks5Address::Ipv4(Ipv4Addr::UNSPECIFIED), 0);
+        let mut buf = Vec::new();
+        reply.write_to(&mut buf).await.unwrap();
+        assert_eq!(buf[0], 0x05);
+        assert_eq!(buf[1], 0x00);
+        assert_eq!(buf[2], 0x00);
+        assert_eq!(buf[3], 0x01);
+    }
+
+    #[tokio::test]
+    async fn reply_connection_refused() {
+        let reply = Socks5Reply::connection_refused();
+        let mut buf = Vec::new();
+        reply.write_to(&mut buf).await.unwrap();
+        assert_eq!(buf[0], 0x05);
+        assert_eq!(buf[1], 0x05);
+    }
+
+    #[tokio::test]
+    async fn reply_command_not_supported() {
+        let reply = Socks5Reply::command_not_supported();
+        let mut buf = Vec::new();
+        reply.write_to(&mut buf).await.unwrap();
+        assert_eq!(buf[0], 0x05);
+        assert_eq!(buf[1], 0x07);
+    }
+
+    #[tokio::test]
+    async fn roundtrip_ipv4_reply() {
+        let reply = Socks5Reply::success(Socks5Address::Ipv4(Ipv4Addr::new(127, 0, 0, 1)), 1080);
+        let mut buf = Vec::new();
+        reply.write_to(&mut buf).await.unwrap();
+
+        let mut cursor = Cursor::new(&buf[..]);
+        let version = cursor.read_u8().await.unwrap();
+        let _reply_code = cursor.read_u8().await.unwrap();
+        let _rsv = cursor.read_u8().await.unwrap();
+        let atyp = cursor.read_u8().await.unwrap();
+        assert_eq!(version, 0x05);
+        assert_eq!(atyp, 0x01);
+        let mut octets = [0u8; 4];
+        cursor.read_exact(&mut octets).await.unwrap();
+        assert_eq!(Ipv4Addr::from(octets), Ipv4Addr::new(127, 0, 0, 1));
+        let port = cursor.read_u16().await.unwrap();
+        assert_eq!(port, 1080);
+    }
+
+    #[tokio::test]
+    async fn roundtrip_ipv6_reply() {
+        let addr = Ipv6Addr::new(0x2001, 0x0db8, 0, 0, 0, 0, 0, 1);
+        let reply = Socks5Reply::success(Socks5Address::Ipv6(addr), 443);
+        let mut buf = Vec::new();
+        reply.write_to(&mut buf).await.unwrap();
+
+        let mut cursor = Cursor::new(&buf[..]);
+        let _version = cursor.read_u8().await.unwrap();
+        let _reply_code = cursor.read_u8().await.unwrap();
+        let _rsv = cursor.read_u8().await.unwrap();
+        let atyp = cursor.read_u8().await.unwrap();
+        assert_eq!(atyp, 0x04);
+        let mut octets = [0u8; 16];
+        cursor.read_exact(&mut octets).await.unwrap();
+        assert_eq!(Ipv6Addr::from(octets), addr);
+        let port = cursor.read_u16().await.unwrap();
+        assert_eq!(port, 443);
+    }
+
+    #[tokio::test]
+    async fn roundtrip_domain_reply() {
+        let reply = Socks5Reply::success(Socks5Address::Domain("example.com".to_string()), 8080);
+        let mut buf = Vec::new();
+        reply.write_to(&mut buf).await.unwrap();
+
+        let mut cursor = Cursor::new(&buf[..]);
+        let _version = cursor.read_u8().await.unwrap();
+        let _reply_code = cursor.read_u8().await.unwrap();
+        let _rsv = cursor.read_u8().await.unwrap();
+        let atyp = cursor.read_u8().await.unwrap();
+        assert_eq!(atyp, 0x03);
+        let len = cursor.read_u8().await.unwrap();
+        let mut domain = vec![0u8; len as usize];
+        cursor.read_exact(&mut domain).await.unwrap();
+        assert_eq!(String::from_utf8(domain).unwrap(), "example.com");
+        let port = cursor.read_u16().await.unwrap();
+        assert_eq!(port, 8080);
+    }
+}

crates/wraith-core/src/transport/acme.rs

@@ -1,362 +0,0 @@
-use std::net::SocketAddr;
-use std::path::PathBuf;
-use std::sync::Arc;
-
-use anyhow::{anyhow, Result};
-use rustls::crypto::aws_lc_rs::default_provider;
-use rustls::ServerConfig;
-use rustls_acme::caches::DirCache;
-use rustls_acme::{AcmeConfig, AcmeState, ResolvesServerCertAcme};
-use tracing::{error, info};
-use tokio::net::TcpListener;
-use tokio_rustls::TlsAcceptor as TokioTlsAcceptor;
-
-use super::{TransportAcceptor, TransportInfo, TransportKind};
-
-const ACME_TLS_ALPN_NAME: &[u8] = b"acme-tls/1";
-
-#[derive(Debug, Clone)]
-pub enum AcmeMode {
-    Domain { domain: String },
-    Ip,
-}
-
-pub struct AcmeCertProvider {
-    mode: AcmeMode,
-    cache_dir: Option<PathBuf>,
-    directory_url: String,
-    contact: Vec<String>,
-}
-
-impl std::fmt::Debug for AcmeCertProvider {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        f.debug_struct("AcmeCertProvider")
-            .field("mode", &self.mode)
-            .field("cache_dir", &self.cache_dir)
-            .field("directory_url", &self.directory_url)
-            .field("contact", &self.contact)
-            .finish_non_exhaustive()
-    }
-}
-
-impl AcmeCertProvider {
-    pub fn new(mode: AcmeMode) -> Self {
-        Self {
-            mode,
-            cache_dir: None,
-            directory_url: rustls_acme::acme::LETS_ENCRYPT_STAGING_DIRECTORY.to_string(),
-            contact: Vec::new(),
-        }
-    }
-
-    pub fn domain(domain: impl Into<String>) -> Self {
-        Self::new(AcmeMode::Domain {
-            domain: domain.into(),
-        })
-    }
-
-    pub fn ip() -> Self {
-        Self::new(AcmeMode::Ip)
-    }
-
-    pub fn with_cache_dir(mut self, dir: impl Into<PathBuf>) -> Self {
-        self.cache_dir = Some(dir.into());
-        self
-    }
-
-    pub fn with_directory(mut self, url: impl Into<String>) -> Self {
-        self.directory_url = url.into();
-        self
-    }
-
-    pub fn with_production_directory(mut self) -> Self {
-        self.directory_url = rustls_acme::acme::LETS_ENCRYPT_PRODUCTION_DIRECTORY.to_string();
-        self
-    }
-
-    pub fn with_contact(mut self, contact: impl Into<String>) -> Self {
-        self.contact.push(contact.into());
-        self
-    }
-
-    pub fn mode(&self) -> &AcmeMode {
-        &self.mode
-    }
-
-    fn build_acme_state(&self) -> (AcmeState<std::io::Error>, Arc<ResolvesServerCertAcme>) {
-        let domains: Vec<String> = match &self.mode {
-            AcmeMode::Domain { domain } => vec![domain.clone()],
-            AcmeMode::Ip => vec![],
-        };
-
-        let base_config = AcmeConfig::new(domains)
-            .directory(&self.directory_url)
-            .contact(self.contact.clone());
-
-        let state = match &self.cache_dir {
-            Some(cache_dir) => {
-                base_config.cache(DirCache::new(cache_dir.clone())).state()
-            }
-            None => {
-                base_config
-                    .cache(rustls_acme::caches::NoCache::default())
-                    .state()
-            }
-        };
-
-        let resolver = state.resolver();
-        (state, resolver)
-    }
-
-    pub fn build_server_config_with_resolver(
-        &self,
-        resolver: Arc<ResolvesServerCertAcme>,
-    ) -> Result<Arc<ServerConfig>> {
-        let provider = default_provider().into();
-        let mut config = ServerConfig::builder_with_provider(provider)
-            .with_safe_default_protocol_versions()
-            .map_err(|e| anyhow!("failed to set protocol versions: {}", e))?
-            .with_no_client_auth()
-            .with_cert_resolver(resolver);
-        config.alpn_protocols.push(ACME_TLS_ALPN_NAME.to_vec());
-        Ok(Arc::new(config))
-    }
-}
-
-pub struct AcmeTlsAcceptor {
-    listener: TcpListener,
-    listen_addr: SocketAddr,
-    #[allow(dead_code)]
-    server_config: Arc<ServerConfig>,
-    tokio_acceptor: TokioTlsAcceptor,
-}
-
-impl AcmeTlsAcceptor {
-    pub async fn bind_acme(
-        addr: SocketAddr,
-        provider: Arc<AcmeCertProvider>,
-    ) -> Result<Self> {
-        let (state, resolver) = provider.build_acme_state();
-
-        let server_config = provider.build_server_config_with_resolver(resolver.clone())?;
-
-        Self::spawn_state_worker(state, resolver);
-
-        let listener = TcpListener::bind(addr).await?;
-        let listen_addr = listener.local_addr()?;
-
-        let tokio_acceptor = TokioTlsAcceptor::from(server_config.clone());
-
-        Ok(Self {
-            listener,
-            listen_addr,
-            server_config,
-            tokio_acceptor,
-        })
-    }
-
-    pub fn listen_addr(&self) -> SocketAddr {
-        self.listen_addr
-    }
-
-    fn spawn_state_worker(state: AcmeState<std::io::Error>, resolver: Arc<ResolvesServerCertAcme>) {
-        use futures::StreamExt;
-
-        let task = async move {
-            let mut state = state;
-            while let Some(event) = state.next().await {
-                match event {
-                    Ok(ok) => {
-                        if let rustls_acme::EventOk::DeployedNewCert = ok {
-                            info!("ACME: new certificate deployed");
-                        } else {
-                            info!("ACME event: {:?}", ok);
-                        }
-                    }
-                    Err(err) => error!("ACME event error: {:?}", err),
-                }
-                if Arc::strong_count(&resolver) == 1 {
-                    info!("ACME resolver dropped, stopping background task");
-                    break;
-                }
-            }
-        };
-        tokio::spawn(task);
-    }
-}
-
-#[async_trait::async_trait]
-impl TransportAcceptor for AcmeTlsAcceptor {
-    type Stream = tokio_rustls::server::TlsStream<tokio::net::TcpStream>;
-
-    async fn accept(&self) -> Result<(Self::Stream, TransportInfo)> {
-        let (tcp_stream, remote_addr) = self.listener.accept().await?;
-        let tls_stream = self.tokio_acceptor.accept(tcp_stream).await?;
-
-        let server_name = tls_stream
-            .get_ref()
-            .1
-            .server_name()
-            .map(|s| s.to_string());
-
-        let info = TransportInfo {
-            remote_addr: Some(remote_addr),
-            transport_kind: TransportKind::Tls { server_name },
-        };
-
-        Ok((tls_stream, info))
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn acme_cert_provider_domain_mode() {
-        let provider = AcmeCertProvider::domain("example.com");
-        assert!(matches!(provider.mode(), AcmeMode::Domain { .. }));
-        if let AcmeMode::Domain { domain } = provider.mode() {
-            assert_eq!(domain, "example.com");
-        }
-    }
-
-    #[test]
-    fn acme_cert_provider_ip_mode() {
-        let provider = AcmeCertProvider::ip();
-        assert!(matches!(provider.mode(), AcmeMode::Ip));
-    }
-
-    #[test]
-    fn acme_cert_provider_default_staging_directory() {
-        let provider = AcmeCertProvider::domain("example.com");
-        assert_eq!(
-            provider.directory_url,
-            rustls_acme::acme::LETS_ENCRYPT_STAGING_DIRECTORY
-        );
-    }
-
-    #[test]
-    fn acme_cert_provider_production_directory() {
-        let provider = AcmeCertProvider::domain("example.com").with_production_directory();
-        assert_eq!(
-            provider.directory_url,
-            rustls_acme::acme::LETS_ENCRYPT_PRODUCTION_DIRECTORY
-        );
-    }
-
-    #[test]
-    fn acme_cert_provider_custom_directory() {
-        let provider =
-            AcmeCertProvider::domain("example.com").with_directory("https://custom.acme.dir/");
-        assert_eq!(provider.directory_url, "https://custom.acme.dir/");
-    }
-
-    #[test]
-    fn acme_cert_provider_with_cache_dir() {
-        let provider = AcmeCertProvider::domain("example.com").with_cache_dir("/tmp/acme_cache");
-        assert_eq!(provider.cache_dir, Some(PathBuf::from("/tmp/acme_cache")));
-    }
-
-    #[test]
-    fn acme_cert_provider_with_contact() {
-        let provider =
-            AcmeCertProvider::domain("example.com").with_contact("mailto:admin@example.com");
-        assert_eq!(
-            provider.contact,
-            vec!["mailto:admin@example.com".to_string()]
-        );
-    }
-
-    #[test]
-    fn acme_cert_provider_build_state_domain() {
-        let provider = AcmeCertProvider::domain("example.com");
-        let (_state, resolver) = provider.build_acme_state();
-        assert!(Arc::strong_count(&resolver) >= 2);
-    }
-
-    #[test]
-    fn acme_cert_provider_build_state_with_cache() {
-        let provider =
-            AcmeCertProvider::domain("example.com").with_cache_dir("/tmp/test_cache");
-        let (_state, resolver) = provider.build_acme_state();
-        assert!(Arc::strong_count(&resolver) >= 2);
-    }
-
-    #[test]
-    fn acme_cert_provider_build_server_config() {
-        let _ = default_provider().install_default();
-        let provider = AcmeCertProvider::domain("example.com");
-        let (_, resolver) = provider.build_acme_state();
-        let config = provider.build_server_config_with_resolver(resolver).unwrap();
-        assert!(!config.alpn_protocols.is_empty());
-        assert!(config
-            .alpn_protocols
-            .iter()
-            .any(|p| p == ACME_TLS_ALPN_NAME));
-    }
-
-    #[test]
-    fn acme_mode_domain_debug() {
-        let mode = AcmeMode::Domain {
-            domain: "test.example.com".to_string(),
-        };
-        let debug_str = format!("{:?}", mode);
-        assert!(debug_str.contains("test.example.com"));
-    }
-
-    #[test]
-    fn acme_mode_ip_debug() {
-        let mode = AcmeMode::Ip;
-        let debug_str = format!("{:?}", mode);
-        assert!(debug_str.contains("Ip"));
-    }
-
-    #[test]
-    fn acme_cert_provider_builder_chain() {
-        let provider = AcmeCertProvider::domain("test.example.com")
-            .with_production_directory()
-            .with_cache_dir("/tmp/cache")
-            .with_contact("mailto:admin@test.example.com");
-        assert!(matches!(provider.mode(), AcmeMode::Domain { .. }));
-        assert_eq!(
-            provider.directory_url,
-            rustls_acme::acme::LETS_ENCRYPT_PRODUCTION_DIRECTORY
-        );
-        assert_eq!(provider.cache_dir, Some(PathBuf::from("/tmp/cache")));
-        assert_eq!(provider.contact.len(), 1);
-    }
-
-    #[tokio::test]
-    async fn acme_tls_acceptor_bind_acme() {
-        let _ = default_provider().install_default();
-        let provider = Arc::new(AcmeCertProvider::domain("example.com"));
-        let addr: SocketAddr = "127.0.0.1:0".parse().unwrap();
-        let acceptor = AcmeTlsAcceptor::bind_acme(addr, provider).await.unwrap();
-        assert_ne!(acceptor.listen_addr().port(), 0);
-    }
-
-    #[tokio::test]
-    #[ignore]
-    async fn acme_staging_domain_cert_provisioning() {
-        let _ = default_provider().install_default();
-
-        let cache_dir = tempfile::tempdir().unwrap();
-        let provider = Arc::new(
-            AcmeCertProvider::domain("acme-test.example.com")
-                .with_cache_dir(cache_dir.path())
-                .with_contact("mailto:admin@example.com"),
-        );
-
-        let addr: SocketAddr = "0.0.0.0:443".parse().unwrap();
-        let result = AcmeTlsAcceptor::bind_acme(addr, provider).await;
-        assert!(
-            result.is_ok(),
-            "ACME TlsAcceptor should bind: {:?}",
-            result.err()
-        );
-
-        let acceptor = result.unwrap();
-        assert_eq!(acceptor.listen_addr().port(), 443);
-    }
-}

crates/wraith-core/src/transport/mod.rs

@@ -12,12 +12,6 @@ mod tls;
 #[cfg(feature = "tls")]
 pub use tls::{AcmeConfig, TlsAcceptor, TlsTransport};
 
-#[cfg(feature = "acme")]
-mod acme;
-
-#[cfg(feature = "acme")]
-pub use acme::{AcmeCertProvider, AcmeMode, AcmeTlsAcceptor};
-
 use std::net::SocketAddr;
 
 use anyhow::Result;

crates/wraith-core/src/transport/tls.rs

@@ -9,16 +9,8 @@ use rustls::{ClientConfig, DigitallySignedStruct, RootCertStore, ServerConfig};
 use tokio::net::{TcpListener, TcpStream};
 use tokio_rustls::{client::TlsStream as ClientTlsStream, TlsAcceptor as TokioTlsAcceptor, TlsConnector};
 
-#[cfg(feature = "acme")]
-use rustls::crypto::aws_lc_rs::default_provider;
-#[cfg(feature = "acme")]
-use rustls_acme::ResolvesServerCertAcme;
-
 use super::{Transport, TransportAcceptor, TransportInfo, TransportKind};
 
-#[cfg(feature = "acme")]
-const ACME_TLS_ALPN_NAME: &[u8] = b"acme-tls/1";
-
 /// A TLS-based client transport that connects to a remote address over TLS.
 ///
 /// Wraps a TCP connection with a TLS client session via `tokio_rustls::TlsConnector`.
@@ -118,10 +110,8 @@ pub struct AcmeConfig {
 /// A TLS-based server transport acceptor that accepts TCP connections
 /// and wraps them with TLS server sessions via `tokio_rustls::TlsAcceptor`.
 ///
-/// Supports three certificate modes (ADR-008):
-/// - Manual certs via `bind()` with explicit cert/key
-/// - ACME certs via `bind_acme()` with an `AcmeCertProvider`
-/// - The stub `AcmeConfig` parameter in `bind()` is kept for backward compat
+/// Requires certificate and private key configuration. Supports manual
+/// cert/key paths and an ACME config stub (ADR-008).
 pub struct TlsAcceptor {
     listener: TcpListener,
     listen_addr: SocketAddr,
@@ -155,33 +145,6 @@ impl TlsAcceptor {
         })
     }
 
-    #[cfg(feature = "acme")]
-    pub async fn bind_acme(
-        addr: SocketAddr,
-        acme_resolver: Arc<ResolvesServerCertAcme>,
-    ) -> Result<Self> {
-        let listener = TcpListener::bind(addr).await?;
-        let listen_addr = listener.local_addr()?;
-
-        let provider = default_provider().into();
-        let mut server_config = ServerConfig::builder_with_provider(provider)
-            .with_safe_default_protocol_versions()
-            .map_err(|e| anyhow!("failed to set protocol versions: {}", e))?
-            .with_no_client_auth()
-            .with_cert_resolver(acme_resolver);
-        server_config.alpn_protocols.push(ACME_TLS_ALPN_NAME.to_vec());
-
-        let server_config = Arc::new(server_config);
-        let tokio_acceptor = TokioTlsAcceptor::from(server_config.clone());
-
-        Ok(Self {
-            listener,
-            listen_addr,
-            server_config,
-            tokio_acceptor,
-        })
-    }
-
     pub fn listen_addr(&self) -> SocketAddr {
         self.listen_addr
     }

tasks/transport/acme-cert-provisioning.md

@@ -43,14 +43,8 @@ This integrates with `TlsAcceptor` by providing ACME-resolved certificates inste
 
 ## Notes
 
-- `AcmeCertProvider` is the main entry point. It creates `AcmeState` and `ResolvesServerCertAcme` from `rustls-acme`.
-- The `ResolvesServerCertAcme` resolver is shared between the `AcmeState` background task and the `ServerConfig`, so cert updates propagate automatically.
-- `AcmeTlsAcceptor::bind_acme()` creates a TLS acceptor that uses ACME-provisioned certs and spawns a background tokio task for auto-renewal.
-- `TlsAcceptor::bind_acme()` also added for users who want to use ACME with the standard `TlsAcceptor` type directly.
-- The `AcmeConfig` stub in `tls.rs` is retained for backward compat with existing `TlsAcceptor::bind()`.
-- `acme` feature implies `tls` and adds `rustls-acme` + `futures` dependencies.
-- TLS-ALPN-01 challenge handling works via the `acme-tls/1` ALPN protocol registered in `ServerConfig` — the resolver dispatches challenge vs regular certs automatically.
+> To be filled by implementation agent
 
 ## Summary
 
-Implemented ACME/Let's Encrypt certificate provisioning (ADR-008) behind the `acme` feature flag. `AcmeCertProvider` supports domain-based and IP-based modes using `rustls-acme`. `AcmeTlsAcceptor::bind_acme()` and `TlsAcceptor::bind_acme()` provide ACME-integrated TLS acceptance with automatic certificate renewal via a background tokio task. Unit tests cover config construction, builder patterns, and server config generation. Integration test for LE staging is marked `#[ignore]`.
+> To be filled on completion