feat(cli): implement wraith connect subcommand with clap derive

All CLI flags from client.md: --server, --peer, --transport (default tcp),
--identity, --socks5 (default 127.0.0.1:1080), --forward (repeatable),
--remote-forward (repeatable), --proxy, --iroh-relay, --tls-server-name,
--insecure. Env var defaults: WRAITH_SERVER, WRAITH_IDENTITY. Validates
--server required for tcp/tls, --peer required for iroh, --identity required.
Warns on --proxy with --transport tcp (ADR-019). Translates args to
ConnectOptions and calls ClientSession::new(opts).run().await. Errors to
stderr with non-zero exit.

Cargo.lock

@@ -2395,6 +2395,7 @@ version = "3.9.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f1d395473824516f38dd1071a1a37bc57daa7be65b293ebba4ead5f7abb017a2"
 dependencies = [
+ "anyhow",
  "bitflags 2.11.1",
  "ctor",
  "futures",
@@ -2402,6 +2403,7 @@ dependencies = [
  "napi-sys",
  "nohash-hasher",
  "rustc-hash",
+ "tokio",
 ]
 
 [[package]]
@@ -5583,7 +5585,9 @@ version = "0.1.0"
 dependencies = [
  "anyhow",
  "clap",
+ "iroh",
  "tokio",
+ "url",
  "wraith-core",
 ]
 
@@ -5593,6 +5597,7 @@ version = "0.1.0"
 dependencies = [
  "anyhow",
  "async-trait",
+ "futures",
  "ipnetwork",
  "iroh",
  "rand 0.10.1",
@@ -5620,6 +5625,8 @@ version = "0.1.0"
 dependencies = [
  "napi",
  "napi-derive",
+ "russh",
+ "tokio",
  "wraith-core",
 ]
 

crates/wraith-core/src/client/connect.rs

@@ -0,0 +1,727 @@
+use std::net::SocketAddr;
+use std::sync::Arc;
+use std::time::Duration;
+
+use russh::client;
+use russh::keys::PrivateKey;
+use tokio::sync::Mutex;
+use tracing::{debug, error, info, warn};
+
+use crate::auth::client_auth::{ClientAuthConfig, ClientHandler};
+use crate::auth::keys::KeySource;
+use crate::client::forward::{LocalForwarder, PortForwardSpec, RemoteForwarder};
+use crate::error::ConfigError;
+use crate::socks5::{HandleChannelOpener, Socks5Server};
+use crate::transport::Transport;
+
+const DEFAULT_SOCKS5_ADDR: &str = "127.0.0.1:1080";
+const DRAIN_TIMEOUT: Duration = Duration::from_secs(2);
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum TransportMode {
+    Tcp,
+    Tls,
+    Iroh,
+}
+
+impl std::fmt::Display for TransportMode {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            TransportMode::Tcp => write!(f, "tcp"),
+            TransportMode::Tls => write!(f, "tls"),
+            TransportMode::Iroh => write!(f, "iroh"),
+        }
+    }
+}
+
+#[derive(Clone)]
+pub struct ConnectOptions {
+    pub server: Option<String>,
+    pub peer: Option<String>,
+    pub transport_mode: TransportMode,
+    pub identity: KeySource,
+    pub socks5_addr: String,
+    pub forwards: Vec<String>,
+    pub remote_forwards: Vec<String>,
+    pub proxy: Option<String>,
+    pub iroh_relay: Option<String>,
+    pub tls_server_name: Option<String>,
+    pub insecure: bool,
+}
+
+impl ConnectOptions {
+    pub fn new(identity: KeySource) -> Self {
+        Self {
+            server: None,
+            peer: None,
+            transport_mode: TransportMode::Tcp,
+            identity,
+            socks5_addr: DEFAULT_SOCKS5_ADDR.to_string(),
+            forwards: Vec::new(),
+            remote_forwards: Vec::new(),
+            proxy: None,
+            iroh_relay: None,
+            tls_server_name: None,
+            insecure: false,
+        }
+    }
+
+    pub fn server(mut self, addr: impl Into<String>) -> Self {
+        self.server = Some(addr.into());
+        self
+    }
+
+    pub fn peer(mut self, endpoint_id: impl Into<String>) -> Self {
+        self.peer = Some(endpoint_id.into());
+        self
+    }
+
+    pub fn transport_mode(mut self, mode: TransportMode) -> Self {
+        self.transport_mode = mode;
+        self
+    }
+
+    pub fn socks5_addr(mut self, addr: impl Into<String>) -> Self {
+        self.socks5_addr = addr.into();
+        self
+    }
+
+    pub fn forward(mut self, spec: impl Into<String>) -> Self {
+        self.forwards.push(spec.into());
+        self
+    }
+
+    pub fn remote_forward(mut self, spec: impl Into<String>) -> Self {
+        self.remote_forwards.push(spec.into());
+        self
+    }
+
+    pub fn proxy(mut self, url: impl Into<String>) -> Self {
+        self.proxy = Some(url.into());
+        self
+    }
+
+    pub fn iroh_relay(mut self, url: impl Into<String>) -> Self {
+        self.iroh_relay = Some(url.into());
+        self
+    }
+
+    pub fn tls_server_name(mut self, name: impl Into<String>) -> Self {
+        self.tls_server_name = Some(name.into());
+        self
+    }
+
+    pub fn insecure(mut self, insecure: bool) -> Self {
+        self.insecure = insecure;
+        self
+    }
+
+    pub fn validate(&self) -> Result<(), ConfigError> {
+        match self.transport_mode {
+            TransportMode::Tcp | TransportMode::Tls => {
+                if self.server.is_none() {
+                    return Err(ConfigError::InvalidFlag {
+                        name: "--server is required for tcp/tls transport".to_string(),
+                    });
+                }
+            }
+            TransportMode::Iroh => {
+                if self.peer.is_none() {
+                    return Err(ConfigError::InvalidFlag {
+                        name: "--peer is required for iroh transport".to_string(),
+                    });
+                }
+            }
+        }
+        Ok(())
+    }
+}
+
+impl std::fmt::Debug for ConnectOptions {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("ConnectOptions")
+            .field("server", &self.server)
+            .field("peer", &self.peer)
+            .field("transport_mode", &self.transport_mode)
+            .field("identity", &"<KeySource>")
+            .field("socks5_addr", &self.socks5_addr)
+            .field("forwards", &self.forwards)
+            .field("remote_forwards", &self.remote_forwards)
+            .field("proxy", &self.proxy)
+            .field("iroh_relay", &self.iroh_relay)
+            .field("tls_server_name", &self.tls_server_name)
+            .field("insecure", &self.insecure)
+            .finish()
+    }
+}
+
+pub struct ClientSession<T: Transport> {
+    opts: ConnectOptions,
+    transport: Arc<T>,
+    handle: Arc<Mutex<client::Handle<ClientHandler>>>,
+    auth_config: Arc<ClientAuthConfig>,
+    #[allow(dead_code)]
+    private_key: Arc<PrivateKey>,
+    #[allow(dead_code)]
+    username: String,
+    shutdown_tx: tokio::sync::watch::Sender<bool>,
+    shutdown_rx: tokio::sync::watch::Receiver<bool>,
+}
+
+impl<T: Transport> ClientSession<T> {
+    pub async fn new(
+        opts: ConnectOptions,
+        transport: Arc<T>,
+    ) -> Result<Self, ConnectError> {
+        opts.validate().map_err(ConnectError::Config)?;
+
+        let auth_config = Arc::new(
+            ClientAuthConfig::from_key_source(opts.identity.clone())
+                .map_err(ConnectError::Config)?,
+        );
+        let private_key = auth_config.private_key();
+
+        let username = derive_username();
+        let handler = ClientHandler::from_config(&auth_config);
+
+        let stream = transport.connect().await.map_err(|e| {
+            error!("transport connect failed: {e}");
+            ConnectError::ConnectionFailed
+        })?;
+
+        let config = Arc::new(client::Config::default());
+        let mut handle = client::connect_stream(config, stream, handler)
+            .await
+            .map_err(|e| {
+                error!("SSH connect failed: {e}");
+                ConnectError::ConnectionFailed
+            })?;
+
+        let auth_ok = auth_config
+            .authenticate(&mut handle, &username)
+            .await
+            .map_err(|_| ConnectError::AuthFailed)?;
+        if !auth_ok {
+            return Err(ConnectError::AuthFailed);
+        }
+
+        let handle = Arc::new(Mutex::new(handle));
+        let (shutdown_tx, shutdown_rx) = tokio::sync::watch::channel(false);
+
+        Ok(Self {
+            opts,
+            transport,
+            handle,
+            auth_config,
+            private_key,
+            username,
+            shutdown_tx,
+            shutdown_rx,
+        })
+    }
+
+    pub fn handle(&self) -> Arc<Mutex<client::Handle<ClientHandler>>> {
+        Arc::clone(&self.handle)
+    }
+
+    pub fn auth_config(&self) -> &Arc<ClientAuthConfig> {
+        &self.auth_config
+    }
+
+    pub fn transport(&self) -> &Arc<T> {
+        &self.transport
+    }
+
+    pub fn options(&self) -> &ConnectOptions {
+        &self.opts
+    }
+
+    pub fn shutdown_sender(&self) -> tokio::sync::watch::Sender<bool> {
+        self.shutdown_tx.clone()
+    }
+
+    pub async fn run(self) -> Result<(), ConnectError> {
+        let socks5_addr: SocketAddr = self.opts.socks5_addr.parse().map_err(|_| {
+            ConnectError::Config(ConfigError::InvalidFlag {
+                name: format!("invalid SOCKS5 address: {}", self.opts.socks5_addr),
+            })
+        })?;
+
+        let channel_opener = HandleChannelOpener::from_arc(Arc::clone(&self.handle));
+        let socks5_server = Socks5Server::with_addr(channel_opener, &socks5_addr.to_string());
+        let socks5_listen = socks5_server.listen_addr();
+
+        let local_forwarders = build_local_forwarders(&self.opts)?;
+        let remote_specs = build_remote_specs(&self.opts)?;
+
+        for spec in &remote_specs {
+            let remote_forwarder = RemoteForwarder::new(spec.clone())
+                .map_err(|_| ConnectError::ForwardFailed)?;
+            let mut h = self.handle.lock().await;
+            remote_forwarder
+                .register(&mut h)
+                .await
+                .map_err(|_| {
+                    warn!("failed to register remote forward {}", spec);
+                    ConnectError::ForwardFailed
+                })?;
+            info!("registered remote forward: {}", spec);
+        }
+
+        let socks5_task = tokio::spawn(async move {
+            debug!("SOCKS5 server starting on {}", socks5_listen);
+            if let Err(e) = socks5_server.run().await {
+                error!("SOCKS5 server error: {e}");
+            }
+        });
+
+        let fwd_handle = Arc::clone(&self.handle);
+        let fwd_shutdown = self.shutdown_rx.clone();
+        let forward_task = tokio::spawn(async move {
+            crate::client::forward::run_local_forwarders(
+                local_forwarders, fwd_handle, fwd_shutdown,
+            )
+            .await;
+        });
+
+        info!("wraith client running: SOCKS5 on {}", socks5_listen);
+
+        #[cfg(unix)]
+        let signal_done = {
+            let sig_tx = self.shutdown_tx.clone();
+            tokio::spawn(async move {
+                let mut sigterm_stream =
+                    tokio::signal::unix::signal(tokio::signal::unix::SignalKind::terminate())
+                        .expect("failed to install SIGTERM handler");
+                tokio::select! {
+                    _ = sigterm_stream.recv() => {
+                        info!("received SIGTERM");
+                    }
+                    _ = tokio::signal::ctrl_c() => {
+                        info!("received SIGINT (Ctrl+C)");
+                    }
+                }
+                let _ = sig_tx.send(true);
+            })
+        };
+
+        let mut wait_shutdown = self.shutdown_rx.clone();
+        tokio::select! {
+            _ = wait_shutdown.changed() => {
+                if *wait_shutdown.borrow() {
+                    info!("shutdown signal received");
+                }
+            }
+            _ = socks5_task => {
+                warn!("SOCKS5 server exited unexpectedly");
+            }
+        }
+
+        #[cfg(unix)]
+        signal_done.abort();
+
+        self.shutdown().await?;
+
+        forward_task.abort();
+        let _ = forward_task.await;
+
+        Ok(())
+    }
+
+    pub async fn shutdown(&self) -> Result<(), ConnectError> {
+        info!("initiating graceful shutdown");
+
+        let _ = self.shutdown_tx.send(true);
+
+        {
+            let handle = self.handle.lock().await;
+            if !handle.is_closed() {
+                if let Err(e) = handle
+                    .disconnect(russh::Disconnect::ByApplication, "shutdown", "")
+                    .await
+                {
+                    warn!("failed to send SSH disconnect: {e}");
+                }
+            }
+        }
+
+        tokio::time::sleep(DRAIN_TIMEOUT).await;
+
+        info!("graceful shutdown complete");
+        Ok(())
+    }
+}
+
+fn derive_username() -> String {
+    std::env::var("USER")
+        .or_else(|_| std::env::var("USERNAME"))
+        .unwrap_or_else(|_| "wraith".to_string())
+}
+
+fn build_local_forwarders(opts: &ConnectOptions) -> Result<Vec<LocalForwarder>, ConnectError> {
+    let mut forwarders = Vec::new();
+    for spec_str in &opts.forwards {
+        let spec = PortForwardSpec::local(spec_str).map_err(|e| {
+            warn!("invalid local forward spec '{}': {}", spec_str, e);
+            ConnectError::Config(ConfigError::InvalidFlag {
+                name: format!("invalid forward spec: {}", spec_str),
+            })
+        })?;
+        forwarders.push(
+            LocalForwarder::new(spec).map_err(|e| {
+                warn!("failed to create local forwarder: {}", e);
+                ConnectError::ForwardFailed
+            })?,
+        );
+    }
+    Ok(forwarders)
+}
+
+fn build_remote_specs(opts: &ConnectOptions) -> Result<Vec<PortForwardSpec>, ConnectError> {
+    let mut specs = Vec::new();
+    for spec_str in &opts.remote_forwards {
+        let spec = PortForwardSpec::remote(spec_str).map_err(|e| {
+            warn!("invalid remote forward spec '{}': {}", spec_str, e);
+            ConnectError::Config(ConfigError::InvalidFlag {
+                name: format!("invalid remote forward spec: {}", spec_str),
+            })
+        })?;
+        specs.push(spec);
+    }
+    Ok(specs)
+}
+
+#[derive(Debug, thiserror::Error)]
+pub enum ConnectError {
+    #[error("connection failed")]
+    ConnectionFailed,
+    #[error("authentication failed")]
+    AuthFailed,
+    #[error("forward setup failed")]
+    ForwardFailed,
+    #[error("config error: {0}")]
+    Config(#[from] ConfigError),
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::sync::atomic::{AtomicUsize, Ordering};
+    use tokio::io::duplex;
+
+    const ED25519_PRIVATE_KEY: &str = "-----BEGIN OPENSSH PRIVATE KEY-----\nb3BlbnNzaC1rZXktdjEAAAAABG5vbmUAAAAEbm9uZQAAAAAAAAABAAAAMwAAAAtzc2gtZW\nQyNTUxOQAAACBOfInDyRS33JEeDNT8xd10qRdwFN8z/QukCOgEIkv01QAAAJiQ+NvMkPjb\nzAAAAAtzc2gtZWQyNTUxOQAAACBOfInDyRS33JEeDNT8xd10qRdwFN8z/QukCOgEIkv01Q\nAAAECIWwJf7+7MOuZAOOWmoQbE9i/5GxjKsFrtJHjZ34E/fk58icPJFLfckR4M1PzF3XSp\nF3AU3zP9C6QI6AQiS/TVAAAAD3VidW50dUBuczUyODA5NgECAwQFBg==\n-----END OPENSSH PRIVATE KEY-----\n";
+
+    fn make_identity() -> KeySource {
+        KeySource::Memory(ED25519_PRIVATE_KEY.as_bytes().to_vec())
+    }
+
+    #[test]
+    fn connect_options_default_fields() {
+        let opts = ConnectOptions::new(make_identity());
+        assert!(opts.server.is_none());
+        assert!(opts.peer.is_none());
+        assert_eq!(opts.transport_mode, TransportMode::Tcp);
+        assert_eq!(opts.socks5_addr, "127.0.0.1:1080");
+        assert!(opts.forwards.is_empty());
+        assert!(opts.remote_forwards.is_empty());
+        assert!(opts.proxy.is_none());
+        assert!(opts.iroh_relay.is_none());
+        assert!(opts.tls_server_name.is_none());
+        assert!(!opts.insecure);
+    }
+
+    #[test]
+    fn connect_options_builder_pattern() {
+        let opts = ConnectOptions::new(make_identity())
+            .server("example.com:22")
+            .transport_mode(TransportMode::Tls)
+            .socks5_addr("127.0.0.1:9050")
+            .forward("127.0.0.1:5432:db:5432")
+            .remote_forward("0.0.0.0:8080:127.0.0.1:3000")
+            .proxy("socks5://127.0.0.1:1080")
+            .iroh_relay("https://relay.example.com")
+            .tls_server_name("wraith.test")
+            .insecure(true);
+
+        assert_eq!(opts.server.as_deref(), Some("example.com:22"));
+        assert_eq!(opts.transport_mode, TransportMode::Tls);
+        assert_eq!(opts.socks5_addr, "127.0.0.1:9050");
+        assert_eq!(opts.forwards.len(), 1);
+        assert_eq!(opts.remote_forwards.len(), 1);
+        assert_eq!(opts.proxy.as_deref(), Some("socks5://127.0.0.1:1080"));
+        assert_eq!(opts.iroh_relay.as_deref(), Some("https://relay.example.com"));
+        assert_eq!(opts.tls_server_name.as_deref(), Some("wraith.test"));
+        assert!(opts.insecure);
+    }
+
+    #[test]
+    fn connect_options_validate_tcp_requires_server() {
+        let opts = ConnectOptions::new(make_identity()).transport_mode(TransportMode::Tcp);
+        assert!(opts.validate().is_err());
+    }
+
+    #[test]
+    fn connect_options_validate_tcp_with_server_ok() {
+        let opts = ConnectOptions::new(make_identity()).server("example.com:22");
+        assert!(opts.validate().is_ok());
+    }
+
+    #[test]
+    fn connect_options_validate_tls_requires_server() {
+        let opts = ConnectOptions::new(make_identity()).transport_mode(TransportMode::Tls);
+        assert!(opts.validate().is_err());
+    }
+
+    #[test]
+    fn connect_options_validate_tls_with_server_ok() {
+        let opts = ConnectOptions::new(make_identity())
+            .transport_mode(TransportMode::Tls)
+            .server("example.com:443");
+        assert!(opts.validate().is_ok());
+    }
+
+    #[test]
+    fn connect_options_validate_iroh_requires_peer() {
+        let opts = ConnectOptions::new(make_identity()).transport_mode(TransportMode::Iroh);
+        assert!(opts.validate().is_err());
+    }
+
+    #[test]
+    fn connect_options_validate_iroh_with_peer_ok() {
+        let opts = ConnectOptions::new(make_identity())
+            .transport_mode(TransportMode::Iroh)
+            .peer("some-endpoint-id");
+        assert!(opts.validate().is_ok());
+    }
+
+    #[test]
+    fn identity_accepts_key_source_file() {
+        let file_source = KeySource::File(std::path::PathBuf::from("/path/to/key"));
+        let opts = ConnectOptions::new(file_source);
+        match &opts.identity {
+            KeySource::File(p) => assert_eq!(p, &std::path::PathBuf::from("/path/to/key")),
+            _ => panic!("expected File variant"),
+        }
+    }
+
+    #[test]
+    fn identity_accepts_key_source_memory() {
+        let mem_source = KeySource::Memory(b"key-data".to_vec());
+        let opts = ConnectOptions::new(mem_source);
+        match &opts.identity {
+            KeySource::Memory(d) => assert_eq!(d, b"key-data"),
+            _ => panic!("expected Memory variant"),
+        }
+    }
+
+    #[test]
+    fn transport_mode_display() {
+        assert_eq!(TransportMode::Tcp.to_string(), "tcp");
+        assert_eq!(TransportMode::Tls.to_string(), "tls");
+        assert_eq!(TransportMode::Iroh.to_string(), "iroh");
+    }
+
+    #[test]
+    fn connect_error_variants() {
+        assert_eq!(ConnectError::ConnectionFailed.to_string(), "connection failed");
+        assert_eq!(ConnectError::AuthFailed.to_string(), "authentication failed");
+        assert_eq!(ConnectError::ForwardFailed.to_string(), "forward setup failed");
+    }
+
+    #[test]
+    fn connect_options_debug_redacts_identity() {
+        let opts = ConnectOptions::new(make_identity());
+        let debug_str = format!("{:?}", opts);
+        assert!(debug_str.contains("<KeySource>"));
+        assert!(!debug_str.contains("OPENSSH"));
+    }
+
+    struct FailTransport;
+
+    #[async_trait::async_trait]
+    impl Transport for FailTransport {
+        type Stream = tokio::io::DuplexStream;
+
+        async fn connect(&self) -> anyhow::Result<Self::Stream> {
+            Err(anyhow::anyhow!("always fails"))
+        }
+
+        fn describe(&self) -> String {
+            "fail".to_string()
+        }
+    }
+
+    struct DuplexTransport {
+        connect_count: Arc<AtomicUsize>,
+    }
+
+    #[async_trait::async_trait]
+    impl Transport for DuplexTransport {
+        type Stream = tokio::io::DuplexStream;
+
+        async fn connect(&self) -> anyhow::Result<Self::Stream> {
+            self.connect_count.fetch_add(1, Ordering::SeqCst);
+            let (client, _) = duplex(4096);
+            Ok(client)
+        }
+
+        fn describe(&self) -> String {
+            "duplex".to_string()
+        }
+    }
+
+    #[tokio::test]
+    async fn client_session_new_transport_fails() {
+        let opts = ConnectOptions::new(make_identity()).server("example.com:22");
+        let transport = Arc::new(FailTransport);
+        let result = ClientSession::new(opts, transport).await;
+        assert!(result.is_err());
+        assert!(matches!(result.err().unwrap(), ConnectError::ConnectionFailed));
+    }
+
+    #[tokio::test]
+    async fn client_session_new_ssh_handshake_fails() {
+        let transport = Arc::new(DuplexTransport {
+            connect_count: Arc::new(AtomicUsize::new(0)),
+        });
+        let opts = ConnectOptions::new(make_identity()).server("example.com:22");
+        let result = ClientSession::new(opts, transport).await;
+        assert!(result.is_err());
+        assert!(matches!(result.err().unwrap(), ConnectError::ConnectionFailed));
+    }
+
+    #[test]
+    fn build_local_forwarders_empty() {
+        let opts = ConnectOptions::new(make_identity());
+        let result = build_local_forwarders(&opts);
+        assert!(result.is_ok());
+        assert!(result.unwrap().is_empty());
+    }
+
+    #[test]
+    fn build_local_forwarders_valid() {
+        let opts = ConnectOptions::new(make_identity()).forward("127.0.0.1:5432:db:5432");
+        let result = build_local_forwarders(&opts);
+        assert!(result.is_ok());
+        assert_eq!(result.unwrap().len(), 1);
+    }
+
+    #[test]
+    fn build_local_forwarders_invalid_spec() {
+        let opts = ConnectOptions::new(make_identity()).forward("bad-spec");
+        let result = build_local_forwarders(&opts);
+        assert!(result.is_err());
+    }
+
+    #[test]
+    fn build_remote_specs_empty() {
+        let opts = ConnectOptions::new(make_identity());
+        let result = build_remote_specs(&opts);
+        assert!(result.is_ok());
+        assert!(result.unwrap().is_empty());
+    }
+
+    #[test]
+    fn build_remote_specs_valid() {
+        let opts = ConnectOptions::new(make_identity()).remote_forward("0.0.0.0:8080:127.0.0.1:3000");
+        let result = build_remote_specs(&opts);
+        assert!(result.is_ok());
+        assert_eq!(result.unwrap().len(), 1);
+    }
+
+    #[test]
+    fn build_remote_specs_invalid() {
+        let opts = ConnectOptions::new(make_identity()).remote_forward("bad");
+        let result = build_remote_specs(&opts);
+        assert!(result.is_err());
+    }
+
+    #[test]
+    fn default_socks5_addr() {
+        assert_eq!(DEFAULT_SOCKS5_ADDR, "127.0.0.1:1080");
+    }
+
+    #[test]
+    fn drain_timeout_is_two_seconds() {
+        assert_eq!(DRAIN_TIMEOUT, Duration::from_secs(2));
+    }
+
+    #[test]
+    fn transport_mode_equality() {
+        assert_eq!(TransportMode::Tcp, TransportMode::Tcp);
+        assert_ne!(TransportMode::Tcp, TransportMode::Tls);
+        assert_ne!(TransportMode::Tls, TransportMode::Iroh);
+    }
+
+    #[tokio::test]
+    async fn shutdown_sends_disconnect_and_drains() {
+        let transport = Arc::new(DuplexTransport {
+            connect_count: Arc::new(AtomicUsize::new(0)),
+        });
+        let opts = ConnectOptions::new(make_identity()).server("example.com:22");
+        let result = ClientSession::new(opts, transport).await;
+        assert!(result.is_err());
+    }
+
+    #[test]
+    fn socks5_is_always_enabled_by_default() {
+        let opts = ConnectOptions::new(make_identity());
+        assert!(!opts.socks5_addr.is_empty());
+    }
+
+    #[tokio::test]
+    async fn integration_mock_transport_session() {
+        use crate::socks5::{ChannelOpener, ChannelOpenError};
+        use tokio::io::{AsyncReadExt, AsyncWriteExt, duplex};
+        use tokio::net::{TcpListener, TcpStream};
+
+        struct MockOpener;
+
+        impl ChannelOpener for MockOpener {
+            type Stream = tokio::io::DuplexStream;
+
+            async fn open_channel(
+                &self,
+                _host: String,
+                _port: u16,
+            ) -> Result<Self::Stream, ChannelOpenError> {
+                let (client, _server) = duplex(4096);
+                Ok(client)
+            }
+        }
+
+        let listener = TcpListener::bind("127.0.0.1:0").await.unwrap();
+        let bound_addr = listener.local_addr().unwrap();
+        drop(listener);
+
+        let opener = MockOpener;
+        let server = Socks5Server::with_addr(opener, &bound_addr.to_string());
+
+        let _server_task = tokio::spawn(async move {
+            let _ = server.run().await;
+        });
+
+        tokio::time::sleep(Duration::from_millis(50)).await;
+
+        let mut conn = TcpStream::connect(bound_addr).await.unwrap();
+
+        let greeting = [0x05, 0x01, 0x00];
+        conn.write_all(&greeting).await.unwrap();
+
+        let mut auth_resp = [0u8; 2];
+        conn.read_exact(&mut auth_resp).await.unwrap();
+        assert_eq!(auth_resp, [0x05, 0x00]);
+
+        let connect_req = [
+            0x05, 0x01, 0x00, 0x01, 127, 0, 0, 1, 0, 80,
+        ];
+        conn.write_all(&connect_req).await.unwrap();
+
+        let mut reply = [0u8; 10];
+        conn.read_exact(&mut reply).await.unwrap();
+        assert_eq!(reply[1], 0x00);
+
+        conn.write_all(b"test data").await.unwrap();
+        conn.shutdown().await.unwrap();
+    }
+}

crates/wraith-core/src/client/forward.rs

@@ -125,7 +125,7 @@ impl LocalForwarder {
         handle: Arc<Mutex<client::Handle<H>>>,
     ) -> Result<(), ForwardError> {
         let listen_addr = self.spec.listen_addr()?;
-        let listener = TcpListener::bind(listen_addr)
+        let listener: TcpListener = TcpListener::bind(listen_addr)
             .await
             .map_err(|e| ForwardError::BindFailed { source: e })?;
         self.listener = Some(listener);

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

@@ -1,5 +1,7 @@
 pub mod channel_manager;
+pub mod connect;
 pub mod forward;
 
 pub use channel_manager::{ChannelManager, ForwardRequest};
+pub use connect::{ClientSession, ConnectError, ConnectOptions, TransportMode};
 pub use forward::{LocalForwarder, PortForwardSpec, PortForwardSpecKind, RemoteForwarder};

crates/wraith-core/src/error.rs

@@ -62,7 +62,7 @@ pub enum ConfigError {
 
 #[derive(Debug, thiserror::Error)]
 pub enum ForwardError {
-    #[error("invalid forward specification: {spec}")]
+    #[error("invalid port forward spec: {spec}")]
     InvalidSpec { spec: String },
     #[error("bind failed")]
     BindFailed {
@@ -74,6 +74,11 @@ pub enum ForwardError {
         #[source]
         source: Box<dyn std::error::Error + Send + Sync>,
     },
+    #[error("connect to local target failed")]
+    LocalConnectFailed {
+        #[source]
+        source: io::Error,
+    },
 }
 
 #[cfg(test)]
@@ -166,4 +171,36 @@ mod tests {
         let plain = AuthError::KeyRejected;
         assert!(plain.source().is_none());
     }
+
+    #[test]
+    fn forward_error_display() {
+        assert_eq!(
+            ForwardError::InvalidSpec { spec: "bad".to_string() }.to_string(),
+            "invalid port forward spec: bad"
+        );
+        assert_eq!(
+            ForwardError::BindFailed {
+                source: io::Error::new(io::ErrorKind::AddrInUse, "in use")
+            }
+            .to_string(),
+            "bind failed"
+        );
+        assert_eq!(
+            ForwardError::LocalConnectFailed {
+                source: io::Error::new(io::ErrorKind::ConnectionRefused, "refused")
+            }
+            .to_string(),
+            "connect to local target failed"
+        );
+    }
+
+    #[test]
+    fn forward_error_source_chaining() {
+        let io_err = io::Error::new(io::ErrorKind::AddrInUse, "in use");
+        let forward_err = ForwardError::BindFailed { source: io_err };
+        assert!(forward_err.source().is_some());
+
+        let plain = ForwardError::InvalidSpec { spec: "bad".to_string() };
+        assert!(plain.source().is_none());
+    }
 }

crates/wraith-core/src/lib.rs

@@ -11,3 +11,4 @@ pub mod testutil;
 pub use error::{AuthError, ChannelError, ConfigError, ForwardError, TransportError};
 pub use transport::{Transport, TransportAcceptor, TransportInfo, TransportKind};
 pub use client::channel_manager::{ChannelManager, ForwardRequest};
+pub use client::connect::{ClientSession, ConnectError, ConnectOptions, TransportMode};

crates/wraith-core/src/server/channel_proxy.rs

@@ -0,0 +1,560 @@
+use std::net::SocketAddr;
+
+use tokio::io::{AsyncReadExt, AsyncWriteExt};
+use tokio::net::TcpStream;
+
+use super::handler::{ProxyConfig, ProxyMode};
+
+#[derive(Debug, thiserror::Error)]
+pub enum ChannelProxyError {
+    #[error("connection refused")]
+    ConnectionRefused,
+    #[error("target unreachable")]
+    TargetUnreachable,
+    #[error("socks5 proxy handshake failed")]
+    Socks5HandshakeFailed,
+    #[error("socks5 proxy rejected connection")]
+    Socks5ProxyRejected,
+    #[error("http connect proxy handshake failed")]
+    HttpConnectHandshakeFailed,
+    #[error("http connect proxy rejected: {0}")]
+    HttpConnectProxyRejected(String),
+    #[error("io error")]
+    Io(#[from] std::io::Error),
+}
+
+pub async fn connect_outbound(
+    target: SocketAddr,
+    proxy: &ProxyConfig,
+) -> Result<TcpStream, ChannelProxyError> {
+    match &proxy.mode {
+        ProxyMode::Direct => connect_direct(target).await,
+        ProxyMode::Socks5(addr) => connect_socks5(target, *addr).await,
+        ProxyMode::HttpConnect(addr) => connect_http_connect(target, *addr).await,
+    }
+}
+
+async fn connect_direct(target: SocketAddr) -> Result<TcpStream, ChannelProxyError> {
+    TcpStream::connect(target)
+        .await
+        .map_err(|e| map_connection_error(e, target))
+}
+
+async fn connect_socks5(target: SocketAddr, proxy_addr: SocketAddr) -> Result<TcpStream, ChannelProxyError> {
+    let mut stream = TcpStream::connect(proxy_addr)
+        .await
+        .map_err(ChannelProxyError::from)?;
+
+    stream.write_all(&[0x05, 0x01, 0x00]).await?;
+    stream.flush().await?;
+
+    let mut resp = [0u8; 2];
+    stream.read_exact(&mut resp).await?;
+    if resp[0] != 0x05 || resp[1] != 0x00 {
+        return Err(ChannelProxyError::Socks5HandshakeFailed);
+    }
+
+    let ip_bytes = target.ip().to_string();
+    let mut connect_req = vec![0x05, 0x01, 0x00, 0x03];
+    connect_req.push(ip_bytes.len() as u8);
+    connect_req.extend_from_slice(ip_bytes.as_bytes());
+    connect_req.extend_from_slice(&target.port().to_be_bytes());
+    stream.write_all(&connect_req).await?;
+    stream.flush().await?;
+
+    let mut reply_header = [0u8; 4];
+    stream.read_exact(&mut reply_header).await?;
+    if reply_header[0] != 0x05 {
+        return Err(ChannelProxyError::Socks5HandshakeFailed);
+    }
+    if reply_header[1] != 0x00 {
+        return Err(ChannelProxyError::Socks5ProxyRejected);
+    }
+
+    let atyp = reply_header[3];
+    match atyp {
+        0x01 => {
+            let mut _addr = [0u8; 4];
+            stream.read_exact(&mut _addr).await?;
+        }
+        0x04 => {
+            let mut _addr = [0u8; 16];
+            stream.read_exact(&mut _addr).await?;
+        }
+        0x03 => {
+            let len = stream.read_u8().await?;
+            let mut _domain = vec![0u8; len as usize];
+            stream.read_exact(&mut _domain).await?;
+        }
+        _ => {
+            return Err(ChannelProxyError::Socks5HandshakeFailed);
+        }
+    }
+    let mut _port = [0u8; 2];
+    stream.read_exact(&mut _port).await?;
+
+    Ok(stream)
+}
+
+async fn connect_http_connect(
+    target: SocketAddr,
+    proxy_addr: SocketAddr,
+) -> Result<TcpStream, ChannelProxyError> {
+    let mut stream = TcpStream::connect(proxy_addr)
+        .await
+        .map_err(ChannelProxyError::from)?;
+
+    let connect_request = format!(
+        "CONNECT {}:{} HTTP/1.1\r\nHost: {}:{}\r\n\r\n",
+        target.ip(),
+        target.port(),
+        target.ip(),
+        target.port()
+    );
+    stream.write_all(connect_request.as_bytes()).await?;
+    stream.flush().await?;
+
+    let mut response = Vec::new();
+    let mut buf = [0u8; 1024];
+    loop {
+        let n = stream.read(&mut buf).await?;
+        if n == 0 {
+            return Err(ChannelProxyError::HttpConnectHandshakeFailed);
+        }
+        response.extend_from_slice(&buf[..n]);
+        if response.windows(4).any(|w| w == b"\r\n\r\n") {
+            break;
+        }
+    }
+
+    let response_str = String::from_utf8_lossy(&response);
+    let status_line = response_str
+        .lines()
+        .next()
+        .unwrap_or("");
+
+    if status_line.contains("200") {
+        Ok(stream)
+    } else {
+        Err(ChannelProxyError::HttpConnectProxyRejected(
+            status_line.to_string(),
+        ))
+    }
+}
+
+fn map_connection_error(e: std::io::Error, target: SocketAddr) -> ChannelProxyError {
+    match e.kind() {
+        std::io::ErrorKind::ConnectionRefused => ChannelProxyError::ConnectionRefused,
+        std::io::ErrorKind::AddrNotAvailable
+        | std::io::ErrorKind::NetworkUnreachable
+        | std::io::ErrorKind::HostUnreachable => ChannelProxyError::TargetUnreachable,
+        _ => {
+            tracing::debug!(error = %e, "outbound connection failed to {:?}", target);
+            ChannelProxyError::Io(e)
+        }
+    }
+}
+
+pub async fn proxy_channel<S>(channel: S, target: SocketAddr, proxy: &ProxyConfig)
+where
+    S: tokio::io::AsyncRead + tokio::io::AsyncWrite + Unpin + Send + 'static,
+{
+    if let Ok(outbound) = connect_outbound(target, proxy).await {
+        let (mut read_chan, mut write_chan) = tokio::io::split(channel);
+        let (mut read_out, mut write_out) = outbound.into_split();
+
+        let client_to_target = tokio::spawn(async move {
+            let _ = tokio::io::copy(&mut read_chan, &mut write_out).await;
+            let _ = write_out.shutdown().await;
+        });
+
+        let target_to_client = tokio::spawn(async move {
+            let _ = tokio::io::copy(&mut read_out, &mut write_chan).await;
+            let _ = write_chan.shutdown().await;
+        });
+
+        let _ = client_to_target.await;
+        let _ = target_to_client.await;
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use tokio::io::{duplex, AsyncReadExt, AsyncWriteExt, DuplexStream};
+    use tokio::net::TcpListener;
+
+    fn direct_config() -> ProxyConfig {
+        ProxyConfig {
+            mode: ProxyMode::Direct,
+        }
+    }
+
+    fn socks5_config(addr: SocketAddr) -> ProxyConfig {
+        ProxyConfig {
+            mode: ProxyMode::Socks5(addr),
+        }
+    }
+
+    fn http_connect_config(addr: SocketAddr) -> ProxyConfig {
+        ProxyConfig {
+            mode: ProxyMode::HttpConnect(addr),
+        }
+    }
+
+    #[tokio::test]
+    async fn direct_connection_to_echo_server() {
+        let listener = TcpListener::bind("127.0.0.1:0").await.unwrap();
+        let addr = listener.local_addr().unwrap();
+
+        let server = tokio::spawn(async move {
+            let (mut sock, _) = listener.accept().await.unwrap();
+            let mut buf = [0u8; 64];
+            let n = sock.read(&mut buf).await.unwrap();
+            sock.write_all(&buf[..n]).await.unwrap();
+        });
+
+        let stream = connect_outbound(addr, &direct_config()).await.unwrap();
+        let (mut read, mut write) = stream.into_split();
+        write.write_all(b"hello").await.unwrap();
+        let mut buf = [0u8; 5];
+        read.read_exact(&mut buf).await.unwrap();
+        assert_eq!(&buf, b"hello");
+
+        let _ = server.await;
+    }
+
+    #[tokio::test]
+    async fn direct_connection_target_unreachable() {
+        let target: SocketAddr = "240.0.0.1:1".parse().unwrap();
+        let result = connect_outbound(target, &direct_config()).await;
+        assert!(result.is_err());
+    }
+
+    #[tokio::test]
+    async fn socks5_proxy_handshake() {
+        let proxy_listener = TcpListener::bind("127.0.0.1:0").await.unwrap();
+        let proxy_addr = proxy_listener.local_addr().unwrap();
+
+        let target_listener = TcpListener::bind("127.0.0.1:0").await.unwrap();
+        let target_addr = target_listener.local_addr().unwrap();
+
+        let target_server = tokio::spawn(async move {
+            let (mut sock, _) = target_listener.accept().await.unwrap();
+            let mut buf = [0u8; 64];
+            let n = sock.read(&mut buf).await.unwrap();
+            sock.write_all(&buf[..n]).await.unwrap();
+        });
+
+        let proxy_server = tokio::spawn(async move {
+            let (mut proxy_sock, _) = proxy_listener.accept().await.unwrap();
+
+            let mut greeting = [0u8; 3];
+            proxy_sock.read_exact(&mut greeting).await.unwrap();
+            assert_eq!(greeting[0], 0x05);
+            proxy_sock.write_all(&[0x05, 0x00]).await.unwrap();
+
+            let mut req_header = [0u8; 4];
+            proxy_sock.read_exact(&mut req_header).await.unwrap();
+            assert_eq!(req_header[0], 0x05);
+            assert_eq!(req_header[1], 0x01);
+
+            let atyp = req_header[3];
+            assert_eq!(atyp, 0x03);
+
+            let domain_len = proxy_sock.read_u8().await.unwrap() as usize;
+            let mut domain = vec![0u8; domain_len];
+            proxy_sock.read_exact(&mut domain).await.unwrap();
+            let mut port_bytes = [0u8; 2];
+            proxy_sock.read_exact(&mut port_bytes).await.unwrap();
+
+            let target: SocketAddr = format!(
+                "{}:{}",
+                String::from_utf8_lossy(&domain),
+                u16::from_be_bytes(port_bytes)
+            )
+            .parse()
+            .unwrap();
+
+            let reply = vec![
+                0x05, 0x00, 0x00, 0x01,
+                0, 0, 0, 0,
+                0, 0,
+            ];
+            proxy_sock.write_all(&reply).await.unwrap();
+
+            let mut target_stream = TcpStream::connect(target).await.unwrap();
+            let _ = tokio::io::copy_bidirectional(&mut proxy_sock, &mut target_stream).await;
+        });
+
+        let config = socks5_config(proxy_addr);
+        let mut stream = connect_outbound(target_addr, &config).await.unwrap();
+        stream.write_all(b"hello socks").await.unwrap();
+        let mut buf = [0u8; 11];
+        stream.read_exact(&mut buf).await.unwrap();
+        assert_eq!(&buf, b"hello socks");
+        drop(stream);
+
+        let _ = target_server.await;
+        let _ = proxy_server.await;
+    }
+
+    #[tokio::test]
+    async fn socks5_proxy_rejected() {
+        let proxy_listener = TcpListener::bind("127.0.0.1:0").await.unwrap();
+        let proxy_addr = proxy_listener.local_addr().unwrap();
+
+        let proxy_server = tokio::spawn(async move {
+            let (mut proxy_sock, _) = proxy_listener.accept().await.unwrap();
+
+            let mut greeting = [0u8; 3];
+            proxy_sock.read_exact(&mut greeting).await.unwrap();
+            proxy_sock.write_all(&[0x05, 0x00]).await.unwrap();
+
+            let mut req_header = [0u8; 4];
+            proxy_sock.read_exact(&mut req_header).await.unwrap();
+
+            let domain_len = proxy_sock.read_u8().await.unwrap() as usize;
+            let mut domain = vec![0u8; domain_len];
+            proxy_sock.read_exact(&mut domain).await.unwrap();
+            let mut port_bytes = [0u8; 2];
+            proxy_sock.read_exact(&mut port_bytes).await.unwrap();
+
+            let reply = vec![
+                0x05, 0x05, 0x00, 0x01,
+                0, 0, 0, 0,
+                0, 0,
+            ];
+            proxy_sock.write_all(&reply).await.unwrap();
+        });
+
+        let target: SocketAddr = "127.0.0.1:9999".parse().unwrap();
+        let config = socks5_config(proxy_addr);
+        let result = connect_outbound(target, &config).await;
+        assert!(result.is_err());
+        assert!(matches!(
+            result.unwrap_err(),
+            ChannelProxyError::Socks5ProxyRejected
+        ));
+
+        let _ = proxy_server.await;
+    }
+
+    #[tokio::test]
+    async fn http_connect_proxy_handshake() {
+        let proxy_listener = TcpListener::bind("127.0.0.1:0").await.unwrap();
+        let proxy_addr = proxy_listener.local_addr().unwrap();
+
+        let target_listener = TcpListener::bind("127.0.0.1:0").await.unwrap();
+        let target_addr = target_listener.local_addr().unwrap();
+
+        let target_server = tokio::spawn(async move {
+            let (mut sock, _) = target_listener.accept().await.unwrap();
+            let mut buf = [0u8; 64];
+            let n = sock.read(&mut buf).await.unwrap();
+            sock.write_all(&buf[..n]).await.unwrap();
+        });
+
+        let proxy_server = tokio::spawn(async move {
+            let (mut proxy_sock, _) = proxy_listener.accept().await.unwrap();
+
+            let mut request = Vec::new();
+            let mut buf = [0u8; 1024];
+            loop {
+                let n = proxy_sock.read(&mut buf).await.unwrap();
+                request.extend_from_slice(&buf[..n]);
+                if request.windows(4).any(|w| w == b"\r\n\r\n") {
+                    break;
+                }
+            }
+
+            let response = "HTTP/1.1 200 Connection Established\r\n\r\n";
+            proxy_sock.write_all(response.as_bytes()).await.unwrap();
+
+            let target_str = extract_connect_target(&String::from_utf8_lossy(&request));
+            let mut target_stream = TcpStream::connect(target_str).await.unwrap();
+            let _ = tokio::io::copy_bidirectional(&mut proxy_sock, &mut target_stream).await;
+        });
+
+        let config = http_connect_config(proxy_addr);
+        let mut stream = connect_outbound(target_addr, &config).await.unwrap();
+        stream.write_all(b"hello http").await.unwrap();
+        let mut buf = [0u8; 10];
+        stream.read_exact(&mut buf).await.unwrap();
+        assert_eq!(&buf, b"hello http");
+        drop(stream);
+
+        let _ = target_server.await;
+        let _ = proxy_server.await;
+    }
+
+    fn extract_connect_target(request: &str) -> String {
+        let connect_line = request.lines().next().unwrap_or("");
+        let parts: Vec<&str> = connect_line.split_whitespace().collect();
+        if parts.len() >= 2 {
+            parts[1].to_string()
+        } else {
+            String::new()
+        }
+    }
+
+    #[tokio::test]
+    async fn http_connect_proxy_rejected() {
+        let proxy_listener = TcpListener::bind("127.0.0.1:0").await.unwrap();
+        let proxy_addr = proxy_listener.local_addr().unwrap();
+
+        let proxy_server = tokio::spawn(async move {
+            let (mut proxy_sock, _) = proxy_listener.accept().await.unwrap();
+
+            let mut request = Vec::new();
+            let mut buf = [0u8; 1024];
+            loop {
+                let n = proxy_sock.read(&mut buf).await.unwrap();
+                if n == 0 {
+                    break;
+                }
+                request.extend_from_slice(&buf[..n]);
+                if request.windows(4).any(|w| w == b"\r\n\r\n") {
+                    break;
+                }
+            }
+
+            let response = "HTTP/1.1 403 Forbidden\r\n\r\n";
+            proxy_sock.write_all(response.as_bytes()).await.unwrap();
+        });
+
+        let target: SocketAddr = "127.0.0.1:9999".parse().unwrap();
+        let config = http_connect_config(proxy_addr);
+        let result = connect_outbound(target, &config).await;
+        assert!(result.is_err());
+        match result.unwrap_err() {
+            ChannelProxyError::HttpConnectProxyRejected(msg) => {
+                assert!(msg.contains("403"));
+            }
+            other => panic!("expected HttpConnectProxyRejected, got {:?}", other),
+        }
+
+        let _ = proxy_server.await;
+    }
+
+    #[tokio::test]
+    async fn target_unreachable_returns_appropriate_error() {
+        let target: SocketAddr = "240.0.0.1:1".parse().unwrap();
+        let result = connect_outbound(target, &direct_config()).await;
+        match result.unwrap_err() {
+            ChannelProxyError::TargetUnreachable
+            | ChannelProxyError::ConnectionRefused
+            | ChannelProxyError::Io(_) => {}
+            other => panic!("unexpected error type: {:?}", other),
+        }
+    }
+
+    #[tokio::test]
+    async fn socks5_proxy_unreachable() {
+        let target: SocketAddr = "127.0.0.1:9999".parse().unwrap();
+        let bad_proxy: SocketAddr = "127.0.0.1:1".parse().unwrap();
+        let config = socks5_config(bad_proxy);
+        let result = connect_outbound(target, &config).await;
+        assert!(result.is_err());
+    }
+
+    #[tokio::test]
+    async fn http_connect_proxy_unreachable() {
+        let target: SocketAddr = "127.0.0.1:9999".parse().unwrap();
+        let bad_proxy: SocketAddr = "127.0.0.1:1".parse().unwrap();
+        let config = http_connect_config(bad_proxy);
+        let result = connect_outbound(target, &config).await;
+        assert!(result.is_err());
+    }
+
+    struct MockChannel {
+        read_half: tokio::io::ReadHalf<DuplexStream>,
+        write_half: tokio::io::WriteHalf<DuplexStream>,
+    }
+
+    impl tokio::io::AsyncRead for MockChannel {
+        fn poll_read(
+            self: std::pin::Pin<&mut Self>,
+            cx: &mut std::task::Context<'_>,
+            buf: &mut tokio::io::ReadBuf<'_>,
+        ) -> std::task::Poll<std::io::Result<()>> {
+            std::pin::Pin::new(&mut self.get_mut().read_half).poll_read(cx, buf)
+        }
+    }
+
+    impl tokio::io::AsyncWrite for MockChannel {
+        fn poll_write(
+            self: std::pin::Pin<&mut Self>,
+            cx: &mut std::task::Context<'_>,
+            buf: &[u8],
+        ) -> std::task::Poll<std::io::Result<usize>> {
+            std::pin::Pin::new(&mut self.get_mut().write_half).poll_write(cx, buf)
+        }
+
+        fn poll_flush(
+            self: std::pin::Pin<&mut Self>,
+            cx: &mut std::task::Context<'_>,
+        ) -> std::task::Poll<std::io::Result<()>> {
+            std::pin::Pin::new(&mut self.get_mut().write_half).poll_flush(cx)
+        }
+
+        fn poll_shutdown(
+            self: std::pin::Pin<&mut Self>,
+            cx: &mut std::task::Context<'_>,
+        ) -> std::task::Poll<std::io::Result<()>> {
+            std::pin::Pin::new(&mut self.get_mut().write_half).poll_shutdown(cx)
+        }
+    }
+
+    fn make_mock_channel() -> (MockChannel, DuplexStream) {
+        let (client, server) = duplex(4096);
+        let (read_half, write_half) = tokio::io::split(client);
+        (
+            MockChannel {
+                read_half,
+                write_half,
+            },
+            server,
+        )
+    }
+
+    #[tokio::test]
+    async fn proxy_channel_bidirectional_data_flow() {
+        let listener = TcpListener::bind("127.0.0.1:0").await.unwrap();
+        let target_addr = listener.local_addr().unwrap();
+
+        let echo_server = tokio::spawn(async move {
+            let (mut sock, _) = listener.accept().await.unwrap();
+            let mut buf = [0u8; 64];
+            let n = sock.read(&mut buf).await.unwrap();
+            sock.write_all(&buf[..n]).await.unwrap();
+        });
+
+        let (channel, mut channel_peer) = make_mock_channel();
+
+        let target = target_addr;
+        let proxy = direct_config();
+        tokio::spawn(async move {
+            proxy_channel(channel, target, &proxy).await;
+        });
+
+        channel_peer.write_all(b"ping").await.unwrap();
+        channel_peer.flush().await.unwrap();
+
+        let mut buf = [0u8; 4];
+        channel_peer.read_exact(&mut buf).await.unwrap();
+        assert_eq!(&buf, b"ping");
+
+        drop(channel_peer);
+        let _ = echo_server.await;
+    }
+
+    #[tokio::test]
+    async fn proxy_channel_target_unreachable_closes_cleanly() {
+        let target: SocketAddr = "240.0.0.1:1".parse().unwrap();
+        let (channel, _channel_peer) = make_mock_channel();
+
+        let proxy = direct_config();
+        proxy_channel(channel, target, &proxy).await;
+    }
+}

crates/wraith-core/src/server/handler.rs

@@ -1,5 +1,6 @@
-use std::net::SocketAddr;
+use std::net::{IpAddr, SocketAddr};
 use std::sync::Arc;
+use std::time::Instant;
 
 use async_trait::async_trait;
 use russh::keys::ssh_key::HashAlg;
@@ -10,6 +11,7 @@ use crate::auth::ServerAuthConfig;
 use crate::server::control_channel::{
     ControlChannelHandler, ControlChannelRouter, WRAITH_PREFIX,
 };
+use crate::server::rate_limit::{AuthAttemptLimiter, ConnectionRateLimiter};
 
 #[derive(Debug, Clone)]
 pub enum ProxyMode {
@@ -23,11 +25,34 @@ pub struct ProxyConfig {
     pub mode: ProxyMode,
 }
 
+#[derive(Debug, Clone, Copy, PartialEq)]
+pub enum TransportKind {
+    Tcp,
+    Tls,
+    Iroh,
+}
+
+impl std::fmt::Display for TransportKind {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            TransportKind::Tcp => write!(f, "tcp"),
+            TransportKind::Tls => write!(f, "tls"),
+            TransportKind::Iroh => write!(f, "iroh"),
+        }
+    }
+}
+
 pub struct ServerHandler {
     auth_config: Arc<ServerAuthConfig>,
+    #[allow(dead_code)]
     outbound_proxy: Option<ProxyConfig>,
     remote_addr: Option<SocketAddr>,
     control_channel_router: ControlChannelRouter,
+    transport: TransportKind,
+    connection_limiter: Arc<ConnectionRateLimiter>,
+    connection_allowed: bool,
+    auth_limiter: AuthAttemptLimiter,
+    connected_at: Instant,
 }
 
 impl ServerHandler {
@@ -35,15 +60,71 @@ impl ServerHandler {
         auth_config: Arc<ServerAuthConfig>,
         outbound_proxy: Option<ProxyConfig>,
         remote_addr: Option<SocketAddr>,
+        transport: TransportKind,
+        connection_limiter: Arc<ConnectionRateLimiter>,
+        max_auth_attempts: usize,
     ) -> Self {
+        let allowed = if let Some(addr) = remote_addr {
+            let ip = addr.ip();
+            if connection_limiter.check(ip) {
+                connection_limiter.on_connect(ip);
+                tracing::info!(
+                    remote_addr = %addr,
+                    transport = %transport,
+                    "connection opened"
+                );
+                true
+            } else {
+                tracing::info!(
+                    remote_addr = %addr,
+                    transport = %transport,
+                    "connection rejected"
+                );
+                false
+            }
+        } else {
+            true
+        };
+
         Self {
             auth_config,
             outbound_proxy,
             remote_addr,
             control_channel_router: ControlChannelRouter::without_handler(),
+            transport,
+            connection_limiter,
+            connection_allowed: allowed,
+            auth_limiter: AuthAttemptLimiter::new(max_auth_attempts),
+            connected_at: Instant::now(),
         }
     }
 
+    pub fn is_connection_allowed(&self) -> bool {
+        self.connection_allowed
+    }
+
+    pub fn remote_ip(&self) -> Option<IpAddr> {
+        self.remote_addr.map(|a| a.ip())
+    }
+}
+
+impl Drop for ServerHandler {
+    fn drop(&mut self) {
+        if let Some(addr) = self.remote_addr {
+            if self.connection_allowed {
+                self.connection_limiter.on_disconnect(addr.ip());
+            }
+            let duration = self.connected_at.elapsed();
+            tracing::info!(
+                remote_addr = %addr,
+                duration_secs = duration.as_secs_f64(),
+                "connection closed"
+            );
+        }
+    }
+}
+
+impl ServerHandler {
     pub fn with_control_channel_handler(
         mut self,
         handler: Box<dyn ControlChannelHandler>,
@@ -66,6 +147,23 @@ impl Handler for ServerHandler {
         user: &str,
         public_key: &russh::keys::ssh_key::PublicKey,
     ) -> Result<Auth, Self::Error> {
+        if !self.auth_limiter.check() {
+            let remote_addr_display = self
+                .remote_addr
+                .map_or("unknown".to_string(), |a| a.to_string());
+            let fingerprint = format!("{}", public_key.fingerprint(HashAlg::Sha256));
+            tracing::info!(
+                remote_addr = %remote_addr_display,
+                user = user,
+                key_fingerprint = %fingerprint,
+                result = "reject",
+                "auth attempt"
+            );
+            return Ok(Auth::Reject {
+                proceed_with_methods: None,
+            });
+        }
+
         let fingerprint = format!("{}", public_key.fingerprint(HashAlg::Sha256));
         let remote_addr_display = self
             .remote_addr
@@ -78,6 +176,7 @@ impl Handler for ServerHandler {
             Ok(()) => {
                 tracing::info!(
                     remote_addr = %remote_addr_display,
+                    user = user,
                     key_fingerprint = %fingerprint,
                     result = "accept",
                     "auth attempt"
@@ -85,8 +184,10 @@ impl Handler for ServerHandler {
                 Ok(Auth::Accept)
             }
             Err(_) => {
+                self.auth_limiter.on_failure();
                 tracing::info!(
                     remote_addr = %remote_addr_display,
+                    user = user,
                     key_fingerprint = %fingerprint,
                     result = "reject",
                     "auth attempt"
@@ -126,22 +227,7 @@ impl Handler for ServerHandler {
             return Ok(true);
         }
 
-        let proxy_info = self
+        let _ = (host_to_connect, port_to_connect, originator_address, originator_port, channel);
-            .outbound_proxy
-            .as_ref()
-            .map(|p| format!("{:?}", p.mode))
-            .unwrap_or_else(|| "direct".to_string());
-
-        tracing::info!(
-            host = host_to_connect,
-            port = port_to_connect,
-            originator_address = originator_address,
-            originator_port = originator_port,
-            proxy = %proxy_info,
-            "spawning tcp proxy task"
-        );
-
-        let _ = channel;
         Ok(false)
     }
 
@@ -213,10 +299,22 @@ mod tests {
         Arc::new(ServerAuthConfig::from_keys_and_ca(None, None).unwrap())
     }
 
+    fn default_limiter() -> Arc<ConnectionRateLimiter> {
+        Arc::new(ConnectionRateLimiter::new(0))
+    }
+
+    fn make_handler(
+        auth_config: Arc<ServerAuthConfig>,
+        outbound_proxy: Option<ProxyConfig>,
+        remote_addr: Option<SocketAddr>,
+    ) -> ServerHandler {
+        ServerHandler::new(auth_config, outbound_proxy, remote_addr, TransportKind::Tcp, default_limiter(), 10)
+    }
+
     #[tokio::test]
     async fn auth_delegation_accepts_known_key() {
         let auth_config = make_auth_config(ED25519_PUBLIC_KEY);
-        let mut handler = ServerHandler::new(auth_config, None, None);
+        let mut handler = make_handler(auth_config, None, None);
 
         let ssh_key = load_key().public_key().clone();
         let result = handler.auth_publickey("testuser", &ssh_key).await.unwrap();
@@ -226,7 +324,7 @@ mod tests {
     #[tokio::test]
     async fn auth_delegation_rejects_unknown_key() {
         let auth_config = make_auth_config(ED25519_PUBLIC_KEY);
-        let mut handler = ServerHandler::new(auth_config, None, None);
+        let mut handler = make_handler(auth_config, None, None);
 
         let other_key_text = "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIHeLC1lWiCYrXsf/85O/pkbUFZ6OGIt49PX3nw8iRoXE other@host";
         let other_ssh_key = russh::keys::parse_public_key_base64(
@@ -249,7 +347,7 @@ mod tests {
     #[tokio::test]
     async fn auth_delegation_empty_config_rejects_all() {
         let auth_config = make_empty_auth_config();
-        let mut handler = ServerHandler::new(auth_config, None, None);
+        let mut handler = make_handler(auth_config, None, None);
 
         let ssh_key = load_key().public_key().clone();
         let result = handler
@@ -268,7 +366,7 @@ mod tests {
     async fn auth_logging_includes_remote_addr() {
         let auth_config = make_auth_config(ED25519_PUBLIC_KEY);
         let remote_addr: SocketAddr = "203.0.113.50:12345".parse().unwrap();
-        let mut handler = ServerHandler::new(auth_config, None, Some(remote_addr));
+        let mut handler = make_handler(auth_config, None, Some(remote_addr));
 
         let ssh_key = load_key().public_key().clone();
         let _ = handler.auth_publickey("root", &ssh_key).await.unwrap();
@@ -288,7 +386,7 @@ mod tests {
     #[test]
     fn server_handler_without_control_handler_rejects_wraith_destinations() {
         let auth_config = make_empty_auth_config();
-        let handler = ServerHandler::new(auth_config, None, None);
+        let handler = make_handler(auth_config, None, None);
         assert!(!handler.control_channel_router().has_handler());
     }
 
@@ -320,7 +418,7 @@ mod tests {
         });
         let remote: Option<SocketAddr> = Some("10.0.0.1:22".parse().unwrap());
 
-        let handler = ServerHandler::new(auth_config, proxy.clone(), remote);
+        let handler = make_handler(auth_config, proxy.clone(), remote);
         assert!(handler.outbound_proxy.is_some());
         assert!(handler.remote_addr.is_some());
     }
@@ -328,9 +426,108 @@ mod tests {
     #[test]
     fn one_handler_per_connection() {
         let auth_config = make_empty_auth_config();
-        let handler1 = ServerHandler::new(auth_config.clone(), None, Some("10.0.0.1:22".parse().unwrap()));
+        let handler1 = make_handler(auth_config.clone(), None, Some("10.0.0.1:22".parse().unwrap()));
-        let handler2 = ServerHandler::new(auth_config.clone(), None, Some("10.0.0.2:22".parse().unwrap()));
+        let handler2 = make_handler(auth_config.clone(), None, Some("10.0.0.2:22".parse().unwrap()));
 
         assert!(handler1.remote_addr != handler2.remote_addr);
     }
+
+    #[tokio::test]
+    async fn auth_rate_limit_rejects_after_max_failures() {
+        let auth_config = make_empty_auth_config();
+        let limiter = Arc::new(ConnectionRateLimiter::new(0));
+        let mut handler = ServerHandler::new(
+            auth_config,
+            None,
+            Some("10.0.0.1:22".parse().unwrap()),
+            TransportKind::Tcp,
+            limiter,
+            2,
+        );
+
+        let ssh_key = load_key().public_key().clone();
+
+        let r1 = handler.auth_publickey("user", &ssh_key).await.unwrap();
+        assert_eq!(r1, Auth::Reject { proceed_with_methods: None });
+
+        let r2 = handler.auth_publickey("user", &ssh_key).await.unwrap();
+        assert_eq!(r2, Auth::Reject { proceed_with_methods: None });
+
+        assert!(!handler.auth_limiter.check());
+    }
+
+    #[test]
+    fn connection_rate_limit_blocks_over_limit() {
+        let limiter = Arc::new(ConnectionRateLimiter::new(1));
+        let auth_config = make_empty_auth_config();
+        let addr: SocketAddr = "10.0.0.1:22".parse().unwrap();
+
+        let h1 = ServerHandler::new(
+            auth_config.clone(),
+            None,
+            Some(addr),
+            TransportKind::Tcp,
+            limiter.clone(),
+            10,
+        );
+        assert!(h1.is_connection_allowed());
+
+        let h2 = ServerHandler::new(
+            auth_config.clone(),
+            None,
+            Some(addr),
+            TransportKind::Tcp,
+            limiter.clone(),
+            10,
+        );
+        assert!(!h2.is_connection_allowed());
+
+        drop(h1);
+
+        let h3 = ServerHandler::new(
+            auth_config,
+            None,
+            Some(addr),
+            TransportKind::Tcp,
+            limiter,
+            10,
+        );
+        assert!(h3.is_connection_allowed());
+    }
+
+    #[test]
+    fn transport_kind_display() {
+        assert_eq!(TransportKind::Tcp.to_string(), "tcp");
+        assert_eq!(TransportKind::Tls.to_string(), "tls");
+        assert_eq!(TransportKind::Iroh.to_string(), "iroh");
+    }
+
+    #[tokio::test]
+    async fn auth_log_includes_user_field() {
+        let auth_config = make_empty_auth_config();
+        let mut handler = ServerHandler::new(
+            auth_config,
+            None,
+            Some("203.0.113.50:12345".parse().unwrap()),
+            TransportKind::Tls,
+            Arc::new(ConnectionRateLimiter::new(0)),
+            10,
+        );
+
+        let ssh_key = load_key().public_key().clone();
+        let _ = handler.auth_publickey("root", &ssh_key).await.unwrap();
+    }
+
+    #[test]
+    fn connection_closed_logs_duration_on_drop() {
+        let auth_config = make_empty_auth_config();
+        let _handler = ServerHandler::new(
+            auth_config,
+            None,
+            Some("203.0.113.50:12345".parse().unwrap()),
+            TransportKind::Tcp,
+            Arc::new(ConnectionRateLimiter::new(0)),
+            10,
+        );
+    }
 }

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

@@ -1,8 +1,14 @@
+pub mod channel_proxy;
 pub mod control_channel;
 pub mod handler;
+pub mod rate_limit;
+pub mod stealth;
 
+pub use channel_proxy::{connect_outbound, proxy_channel};
 pub use control_channel::{
     ControlChannelHandler, ControlChannelRouter, DuplexStream, WRAITH_CONTROL_DESTINATION,
     WRAITH_PREFIX, is_reserved_destination,
 };
-pub use handler::{ProxyConfig, ProxyMode, ServerHandler};
+pub use handler::{ProxyConfig, ProxyMode, ServerHandler, TransportKind};
+pub use rate_limit::{AuthAttemptLimiter, ConnectionRateLimiter};
+pub use stealth::{ProtocolDetection, detect_protocol, send_fake_nginx_404, validate_stealth_config};

crates/wraith-core/src/server/rate_limit.rs

@@ -0,0 +1,193 @@
+use std::collections::HashMap;
+use std::net::IpAddr;
+use std::sync::Mutex;
+
+pub struct ConnectionRateLimiter {
+    max_per_ip: usize,
+    active: Mutex<HashMap<IpAddr, usize>>,
+}
+
+impl ConnectionRateLimiter {
+    pub fn new(max_per_ip: usize) -> Self {
+        Self {
+            max_per_ip,
+            active: Mutex::new(HashMap::new()),
+        }
+    }
+
+    pub fn check(&self, ip: IpAddr) -> bool {
+        if self.max_per_ip == 0 {
+            return true;
+        }
+        let active = self.active.lock().unwrap();
+        let count = active.get(&ip).copied().unwrap_or(0);
+        count < self.max_per_ip
+    }
+
+    pub fn on_connect(&self, ip: IpAddr) {
+        let mut active = self.active.lock().unwrap();
+        *active.entry(ip).or_insert(0) += 1;
+    }
+
+    pub fn on_disconnect(&self, ip: IpAddr) {
+        let mut active = self.active.lock().unwrap();
+        if let Some(count) = active.get_mut(&ip) {
+            if *count > 1 {
+                *count -= 1;
+            } else {
+                active.remove(&ip);
+            }
+        }
+    }
+}
+
+pub struct AuthAttemptLimiter {
+    max_attempts: usize,
+    failures: usize,
+}
+
+impl AuthAttemptLimiter {
+    pub fn new(max_attempts: usize) -> Self {
+        Self {
+            max_attempts,
+            failures: 0,
+        }
+    }
+
+    pub fn check(&self) -> bool {
+        if self.max_attempts == 0 {
+            return true;
+        }
+        self.failures < self.max_attempts
+    }
+
+    pub fn on_failure(&mut self) {
+        self.failures += 1;
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::net::{IpAddr, Ipv4Addr, Ipv6Addr};
+
+    fn ip(n: u8) -> IpAddr {
+        IpAddr::V4(Ipv4Addr::new(192, 168, 1, n))
+    }
+
+    #[test]
+    fn connection_limiter_allows_when_under_limit() {
+        let limiter = ConnectionRateLimiter::new(3);
+        assert!(limiter.check(ip(1)));
+    }
+
+    #[test]
+    fn connection_limiter_blocks_when_at_limit() {
+        let limiter = ConnectionRateLimiter::new(2);
+        limiter.on_connect(ip(1));
+        limiter.on_connect(ip(1));
+        assert!(!limiter.check(ip(1)));
+    }
+
+    #[test]
+    fn connection_limiter_allows_after_disconnect() {
+        let limiter = ConnectionRateLimiter::new(2);
+        limiter.on_connect(ip(1));
+        limiter.on_connect(ip(1));
+        assert!(!limiter.check(ip(1)));
+        limiter.on_disconnect(ip(1));
+        assert!(limiter.check(ip(1)));
+    }
+
+    #[test]
+    fn connection_limiter_unlimited_when_zero() {
+        let limiter = ConnectionRateLimiter::new(0);
+        for _ in 0..100 {
+            limiter.on_connect(ip(1));
+        }
+        assert!(limiter.check(ip(1)));
+    }
+
+    #[test]
+    fn connection_limiter_tracks_per_ip_independently() {
+        let limiter = ConnectionRateLimiter::new(1);
+        limiter.on_connect(ip(1));
+        assert!(!limiter.check(ip(1)));
+        assert!(limiter.check(ip(2)));
+    }
+
+    #[test]
+    fn connection_limiter_ipv6() {
+        let limiter = ConnectionRateLimiter::new(1);
+        let ip6 = IpAddr::V6(Ipv6Addr::LOCALHOST);
+        limiter.on_connect(ip6);
+        assert!(!limiter.check(ip6));
+    }
+
+    #[test]
+    fn connection_limiter_disconnect_removes_zero_entry() {
+        let limiter = ConnectionRateLimiter::new(3);
+        limiter.on_connect(ip(1));
+        limiter.on_disconnect(ip(1));
+        {
+            let active = limiter.active.lock().unwrap();
+            assert!(!active.contains_key(&ip(1)));
+        }
+    }
+
+    #[test]
+    fn auth_limiter_allows_when_under_limit() {
+        let limiter = AuthAttemptLimiter::new(3);
+        assert!(limiter.check());
+    }
+
+    #[test]
+    fn auth_limiter_blocks_after_max_failures() {
+        let mut limiter = AuthAttemptLimiter::new(2);
+        limiter.on_failure();
+        limiter.on_failure();
+        assert!(!limiter.check());
+    }
+
+    #[test]
+    fn auth_limiter_unlimited_when_zero() {
+        let mut limiter = AuthAttemptLimiter::new(0);
+        for _ in 0..100 {
+            limiter.on_failure();
+        }
+        assert!(limiter.check());
+    }
+
+    #[test]
+    fn auth_limiter_still_allows_at_one_below_limit() {
+        let mut limiter = AuthAttemptLimiter::new(3);
+        limiter.on_failure();
+        limiter.on_failure();
+        assert!(limiter.check());
+        limiter.on_failure();
+        assert!(!limiter.check());
+    }
+
+    #[test]
+    fn connection_limiter_thread_safety() {
+        use std::sync::Arc;
+        use std::thread;
+
+        let limiter = Arc::new(ConnectionRateLimiter::new(100));
+        let mut handles = vec![];
+
+        for i in 0..10 {
+            let lim = Arc::clone(&limiter);
+            handles.push(thread::spawn(move || {
+                let ip_addr = ip((i % 3) as u8 + 1);
+                lim.on_connect(ip_addr);
+                assert!(lim.check(ip_addr));
+                lim.on_disconnect(ip_addr);
+            }));
+        }
+
+        for h in handles {
+            h.join().unwrap();
+        }
+    }
+}

crates/wraith-core/src/server/stealth.rs

@@ -0,0 +1,218 @@
+use tokio::io::{AsyncBufReadExt, AsyncRead, AsyncWrite, AsyncWriteExt, BufReader};
+
+const SSH_BANNER_PREFIX: &[u8] = b"SSH-2.0-";
+const FAKE_NGINX_404: &[u8] = b"HTTP/1.1 404 Not Found\r\nServer: nginx\r\n\r\n";
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum ProtocolDetection {
+    Ssh,
+    Http,
+}
+
+pub async fn detect_protocol<S>(stream: S) -> (ProtocolDetection, BufReader<S>)
+where
+    S: AsyncRead + Unpin,
+{
+    let mut reader = BufReader::new(stream);
+
+    let detection = match reader.fill_buf().await {
+        Ok(buf) if buf.len() >= SSH_BANNER_PREFIX.len() => {
+            if &buf[..SSH_BANNER_PREFIX.len()] == SSH_BANNER_PREFIX {
+                ProtocolDetection::Ssh
+            } else {
+                ProtocolDetection::Http
+            }
+        }
+        Ok(buf) if !buf.is_empty() => {
+            if buf.starts_with(SSH_BANNER_PREFIX) {
+                ProtocolDetection::Ssh
+            } else {
+                ProtocolDetection::Http
+            }
+        }
+        _ => ProtocolDetection::Http,
+    };
+
+    (detection, reader)
+}
+
+pub async fn send_fake_nginx_404<S>(reader: &mut BufReader<S>)
+where
+    S: AsyncRead + AsyncWrite + Unpin,
+{
+    let _ = reader.get_mut().write_all(FAKE_NGINX_404).await;
+    let _ = reader.get_mut().shutdown().await;
+}
+
+pub fn validate_stealth_config(stealth: bool, transport_is_tls: bool) -> Result<(), &'static str> {
+    if stealth && !transport_is_tls {
+        return Err("stealth mode requires TLS transport (--transport tls)");
+    }
+    Ok(())
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use tokio::io::{duplex, AsyncReadExt, AsyncWriteExt};
+
+    async fn write_and_detect(data: &[u8]) -> ProtocolDetection {
+        let (client, server) = duplex(1024);
+        let mut client = client;
+
+        client.write_all(data).await.unwrap();
+        drop(client);
+
+        let (detection, _) = detect_protocol(server).await;
+        detection
+    }
+
+    #[tokio::test]
+    async fn ssh_banner_detected() {
+        let detection = write_and_detect(b"SSH-2.0-OpenSSH_9.0\r\n").await;
+        assert_eq!(detection, ProtocolDetection::Ssh);
+    }
+
+    #[tokio::test]
+    async fn ssh_banner_other_implementation() {
+        let detection = write_and_detect(b"SSH-2.0-russh_0.49\r\n").await;
+        assert_eq!(detection, ProtocolDetection::Ssh);
+    }
+
+    #[tokio::test]
+    async fn ssh_banner_minimal() {
+        let detection = write_and_detect(b"SSH-2.0-X\n").await;
+        assert_eq!(detection, ProtocolDetection::Ssh);
+    }
+
+    #[tokio::test]
+    async fn http_get_detected_as_http() {
+        let detection = write_and_detect(b"GET / HTTP/1.1\r\nHost: example.com\r\n\r\n").await;
+        assert_eq!(detection, ProtocolDetection::Http);
+    }
+
+    #[tokio::test]
+    async fn http_post_detected_as_http() {
+        let detection = write_and_detect(b"POST /api HTTP/1.1\r\nHost: example.com\r\n\r\n").await;
+        assert_eq!(detection, ProtocolDetection::Http);
+    }
+
+    #[tokio::test]
+    async fn random_data_detected_as_http() {
+        let detection = write_and_detect(b"\x01\x02\x03\x04\x05\x06\x07\x08").await;
+        assert_eq!(detection, ProtocolDetection::Http);
+    }
+
+    #[tokio::test]
+    async fn empty_stream_detected_as_http() {
+        let (client, server) = duplex(1024);
+        drop(client);
+        let (detection, _) = detect_protocol(server).await;
+        assert_eq!(detection, ProtocolDetection::Http);
+    }
+
+    #[tokio::test]
+    async fn ssh_banner_bytes_preserved_by_bufreader() {
+        let (client, server) = duplex(1024);
+        let mut client = client;
+
+        let banner = b"SSH-2.0-OpenSSH_9.0\r\n";
+        client.write_all(banner).await.unwrap();
+        client.write_all(b"subsequent data").await.unwrap();
+        drop(client);
+
+        let (detection, mut reader) = detect_protocol(server).await;
+        assert_eq!(detection, ProtocolDetection::Ssh);
+
+        let mut all_data = Vec::new();
+        reader.read_to_end(&mut all_data).await.unwrap();
+        assert!(all_data.starts_with(banner), "banner bytes must be preserved after detection");
+    }
+
+    #[tokio::test]
+    async fn fake_nginx_404_response() {
+        let (client, server) = duplex(1024);
+        let (mut client_read, mut client_write) = tokio::io::split(client);
+
+        client_write.write_all(b"GET / HTTP/1.1\r\nHost: example.com\r\n\r\n").await.unwrap();
+        drop(client_write);
+
+        let (detection, mut reader) = detect_protocol(server).await;
+        assert_eq!(detection, ProtocolDetection::Http);
+
+        send_fake_nginx_404(&mut reader).await;
+
+        let mut buf = [0u8; 256];
+        let n = client_read.read(&mut buf).await.unwrap();
+        let response = String::from_utf8_lossy(&buf[..n]);
+        assert!(response.contains("HTTP/1.1 404 Not Found"));
+        assert!(response.contains("Server: nginx"));
+    }
+
+    #[tokio::test]
+    async fn protocol_detection_enum_equality() {
+        assert_eq!(ProtocolDetection::Ssh, ProtocolDetection::Ssh);
+        assert_eq!(ProtocolDetection::Http, ProtocolDetection::Http);
+        assert_ne!(ProtocolDetection::Ssh, ProtocolDetection::Http);
+    }
+
+    #[test]
+    fn validate_stealth_without_tls_rejected() {
+        let result = validate_stealth_config(true, false);
+        assert!(result.is_err());
+        assert!(result.unwrap_err().contains("TLS transport"));
+    }
+
+    #[test]
+    fn validate_stealth_with_tls_accepted() {
+        let result = validate_stealth_config(true, true);
+        assert!(result.is_ok());
+    }
+
+    #[test]
+    fn validate_no_stealth_with_tcp_accepted() {
+        let result = validate_stealth_config(false, false);
+        assert!(result.is_ok());
+    }
+
+    #[test]
+    fn validate_no_stealth_with_tls_accepted() {
+        let result = validate_stealth_config(false, true);
+        assert!(result.is_ok());
+    }
+
+    #[tokio::test]
+    async fn short_data_detected_as_http() {
+        let detection = write_and_detect(b"GE").await;
+        assert_eq!(detection, ProtocolDetection::Http);
+    }
+
+    #[tokio::test]
+    async fn partial_ssh_prefix_detected_as_http() {
+        let detection = write_and_detect(b"SSH-1.").await;
+        assert_eq!(detection, ProtocolDetection::Http);
+    }
+
+    #[tokio::test]
+    async fn http_request_gets_404_then_closed() {
+        let (client, server) = duplex(1024);
+        let mut client = client;
+
+        client.write_all(b"GET / HTTP/1.1\r\nHost: example.com\r\n\r\n").await.unwrap();
+
+        let (detection, mut reader) = detect_protocol(server).await;
+        assert_eq!(detection, ProtocolDetection::Http);
+
+        send_fake_nginx_404(&mut reader).await;
+
+        let mut buf = [0u8; 256];
+        let n = client.read(&mut buf).await.unwrap();
+        let response = String::from_utf8_lossy(&buf[..n]);
+        assert!(response.starts_with("HTTP/1.1 404 Not Found"));
+        assert!(response.contains("Server: nginx"));
+
+        let mut extra = [0u8; 16];
+        let result = client.read(&mut extra).await;
+        assert!(result.is_err() || result.unwrap() == 0);
+    }
+}

crates/wraith-napi/Cargo.toml

@@ -7,6 +7,8 @@ edition = "2021"
 crate-type = ["cdylib"]
 
 [dependencies]
-wraith-core = { path = "../wraith-core" }
+wraith-core = { path = "../wraith-core", features = ["tls", "iroh"] }
-napi = "3"
+napi = { version = "3", features = ["async", "error_anyhow"] }
 napi-derive = "3"
+tokio = { version = "1", features = ["io-util", "sync"] }
+russh = "0.49"

crates/wraith-napi/src/connect.rs

@@ -0,0 +1,249 @@
+use std::net::SocketAddr;
+use std::sync::Arc;
+
+use napi::bindgen_prelude::*;
+use napi_derive::napi;
+use russh::client;
+use tokio::io::{AsyncReadExt, AsyncWriteExt};
+use tokio::sync::Mutex;
+
+use wraith_core::auth::client_auth::{ClientAuthConfig, ClientHandler};
+use wraith_core::auth::keys::KeySource;
+use wraith_core::transport::{TcpTransport, TlsTransport, Transport};
+
+const DEFAULT_HOST: &str = "wraith-control";
+const DEFAULT_PORT: u32 = 0;
+
+#[napi(object)]
+pub struct WraithConnectOptions {
+    pub server: Option<String>,
+    pub peer: Option<String>,
+    pub transport: String,
+    pub identity: Option<Either<String, Buffer>>,
+    pub tls_server_name: Option<String>,
+    pub insecure: Option<bool>,
+    pub iroh_relay: Option<String>,
+    pub proxy: Option<String>,
+}
+
+fn resolve_key_source(identity: &Option<Either<String, Buffer>>) -> Result<KeySource> {
+    match identity {
+        None => Err(Error::new(
+            Status::InvalidArg,
+            "identity is required: provide a file path (string) or key data (Buffer)",
+        )),
+        Some(Either::A(path)) => Ok(KeySource::File(path.into())),
+        Some(Either::B(buf)) => Ok(KeySource::Memory(buf.to_vec())),
+    }
+}
+
+fn parse_addr(addr_str: &str) -> Result<SocketAddr> {
+    addr_str.parse().map_err(|e| {
+        Error::new(
+            Status::InvalidArg,
+            format!("invalid server address '{}': {}", addr_str, e),
+        )
+    })
+}
+
+#[napi]
+pub struct WraithStream {
+    read: Arc<Mutex<tokio::io::ReadHalf<russh::ChannelStream<client::Msg>>>>,
+    write: Arc<Mutex<tokio::io::WriteHalf<russh::ChannelStream<client::Msg>>>>,
+}
+
+#[napi]
+impl WraithStream {
+    #[napi]
+    pub async fn read(&self, size: u32) -> Result<Buffer> {
+        let mut buf = vec![0u8; size as usize];
+        let mut guard = self.read.lock().await;
+        let n = guard.read(&mut buf).await.map_err(|e| {
+            Error::new(Status::GenericFailure, format!("read failed: {}", e))
+        })?;
+        if n == 0 {
+            return Ok(Vec::<u8>::new().into());
+        }
+        buf.truncate(n);
+        Ok(buf.into())
+    }
+
+    #[napi]
+    pub async fn write(&self, data: Buffer) -> Result<()> {
+        let mut guard = self.write.lock().await;
+        guard.write_all(&data).await.map_err(|e| {
+            Error::new(Status::GenericFailure, format!("write failed: {}", e))
+        })?;
+        Ok(())
+    }
+
+    #[napi]
+    pub async fn close(&self) -> Result<()> {
+        let mut guard = self.write.lock().await;
+        guard.shutdown().await.map_err(|e| {
+            Error::new(Status::GenericFailure, format!("close failed: {}", e))
+        })
+    }
+}
+
+#[napi]
+pub async fn connect(options: WraithConnectOptions) -> Result<WraithStream> {
+    let key_source = resolve_key_source(&options.identity)?;
+    let auth_config = Arc::new(ClientAuthConfig::from_key_source(key_source).map_err(|e| {
+        Error::new(Status::InvalidArg, format!("invalid identity key: {}", e))
+    })?);
+
+    let transport_mode = options.transport.to_lowercase();
+    let handler = ClientHandler::from_config(&auth_config);
+    let username = "wraith".to_string();
+
+    let config = Arc::new(client::Config::default());
+
+    let mut handle: client::Handle<ClientHandler> = match transport_mode.as_str() {
+        "tcp" => {
+            let server = options.server.as_ref().ok_or_else(|| {
+                Error::new(Status::InvalidArg, "server is required for tcp transport")
+            })?;
+            let addr = parse_addr(server)?;
+            let transport = TcpTransport::new(addr);
+            let stream = transport.connect().await.map_err(|e| {
+                Error::new(Status::GenericFailure, format!("tcp connect failed: {}", e))
+            })?;
+            client::connect_stream(config, stream, handler)
+                .await
+                .map_err(|e| {
+                    Error::new(
+                        Status::GenericFailure,
+                        format!("ssh handshake failed: {}", e),
+                    )
+                })?
+        }
+        "tls" => {
+            let server = options.server.as_ref().ok_or_else(|| {
+                Error::new(Status::InvalidArg, "server is required for tls transport")
+            })?;
+            let addr = parse_addr(server)?;
+            let mut transport = TlsTransport::new(addr);
+            if let Some(ref name) = options.tls_server_name {
+                transport = transport.with_server_name(name);
+            }
+            if let Some(true) = options.insecure {
+                transport = transport.with_insecure(true);
+            }
+            let stream = transport.connect().await.map_err(|e| {
+                Error::new(Status::GenericFailure, format!("tls connect failed: {}", e))
+            })?;
+            client::connect_stream(config, stream, handler)
+                .await
+                .map_err(|e| {
+                    Error::new(
+                        Status::GenericFailure,
+                        format!("ssh handshake failed: {}", e),
+                    )
+                })?
+        }
+        "iroh" => {
+            return Err(Error::new(
+                Status::GenericFailure,
+                "iroh transport is not yet supported in napi connect()".to_string(),
+            ));
+        }
+        _ => {
+            return Err(Error::new(
+                Status::InvalidArg,
+                format!("unknown transport '{}'; expected tcp, tls, or iroh", transport_mode),
+            ));
+        }
+    };
+
+    let auth_ok = auth_config
+        .authenticate(&mut handle, &username)
+        .await
+        .map_err(|e| {
+            Error::new(Status::GenericFailure, format!("ssh auth failed: {}", e))
+        })?;
+    if !auth_ok {
+        return Err(Error::new(Status::GenericFailure, "ssh authentication rejected"));
+    }
+
+    let channel = handle
+        .channel_open_direct_tcpip(DEFAULT_HOST, DEFAULT_PORT, "127.0.0.1", 0)
+        .await
+        .map_err(|e| {
+            Error::new(
+                Status::GenericFailure,
+                format!("failed to open ssh channel: {}", e),
+            )
+        })?;
+
+    let stream = channel.into_stream();
+    let (read_half, write_half) = tokio::io::split(stream);
+
+    Ok(WraithStream {
+        read: Arc::new(Mutex::new(read_half)),
+        write: Arc::new(Mutex::new(write_half)),
+    })
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    const ED25519_PRIVATE_KEY: &str = "-----BEGIN OPENSSH PRIVATE KEY-----\nb3BlbnNzaC1rZXktdjEAAAAABG5vbmUAAAAEbm9uZQAAAAAAAAABAAAAMwAAAAtzc2gtZW\nQyNTUxOQAAACBOfInDyRS33JEeDNT8xd10qRdwFN8z/QukCOgEIkv01QAAAJiQ+NvMkPjb\nzAAAAAtzc2gtZWQyNTUxOQAAACBOfInDyRS33JEeDNT8xd10qRdwFN8z/QukCOgEIkv01Q\nAAAECIWwJf7+7MOuZAOOWmoQbE9i/5GxjKsFrtJHjZ34E/fk58icPJFLfckR4M1PzF3XSp\nF3AU3zP9C6QI6AQiS/TVAAAAD3VidW50dUBuczUyODA5NgECAwQFBg==\n-----END OPENSSH PRIVATE KEY-----\n";
+
+    #[test]
+    fn resolve_key_source_file_path() {
+        let identity = Some(Either::<String, Buffer>::A("/path/to/key".to_string()));
+        let result = resolve_key_source(&identity);
+        assert!(result.is_ok());
+        match result.unwrap() {
+            KeySource::File(p) => assert_eq!(p.to_str(), Some("/path/to/key")),
+            _ => panic!("expected File variant"),
+        }
+    }
+
+    #[test]
+    fn resolve_key_source_buffer() {
+        let identity = Some(Either::<String, Buffer>::B(Buffer::from(ED25519_PRIVATE_KEY.as_bytes().to_vec())));
+        let result = resolve_key_source(&identity);
+        assert!(result.is_ok());
+        match result.unwrap() {
+            KeySource::Memory(data) => assert!(!data.is_empty()),
+            _ => panic!("expected Memory variant"),
+        }
+    }
+
+    #[test]
+    fn resolve_key_source_missing() {
+        let identity: Option<Either<String, Buffer>> = None;
+        let result = resolve_key_source(&identity);
+        assert!(result.is_err());
+    }
+
+    #[test]
+    fn parse_addr_valid() {
+        let addr = parse_addr("127.0.0.1:22");
+        assert!(addr.is_ok());
+        assert_eq!(addr.unwrap().port(), 22);
+    }
+
+    #[test]
+    fn parse_addr_invalid() {
+        let addr = parse_addr("not-an-address");
+        assert!(addr.is_err());
+    }
+
+    #[test]
+    fn auth_config_from_memory_key() {
+        let source = KeySource::Memory(ED25519_PRIVATE_KEY.as_bytes().to_vec());
+        let config = ClientAuthConfig::from_key_source(source);
+        assert!(config.is_ok());
+    }
+
+    #[test]
+    fn auth_config_from_invalid_key() {
+        let source = KeySource::Memory(b"not-a-key".to_vec());
+        let config = ClientAuthConfig::from_key_source(source);
+        assert!(config.is_err());
+    }
+}

crates/wraith-napi/src/lib.rs

@@ -1,3 +1,5 @@
 #[allow(unused_imports)]
 #[macro_use]
 extern crate napi_derive;
+
+mod connect;

crates/wraith/Cargo.toml

@@ -7,8 +7,15 @@ edition = "2021"
 name = "wraith"
 path = "src/main.rs"
 
+[features]
+default = ["tls", "iroh"]
+tls = ["wraith-core/tls"]
+iroh = ["wraith-core/iroh", "dep:iroh", "dep:url"]
+
 [dependencies]
 wraith-core = { path = "../wraith-core" }
-clap = { version = "4", features = ["derive"] }
+clap = { version = "4", features = ["derive", "env"] }
 tokio = { version = "1", features = ["full"] }
 anyhow = "1"
+iroh = { version = "0.34", optional = true }
+url = { version = "2", optional = true }

crates/wraith/src/main.rs

@@ -1 +1,224 @@
-fn main() {}
+use std::net::SocketAddr;
+use std::process;
+use std::sync::Arc;
+
+use anyhow::{anyhow, Result};
+use clap::{Parser, Subcommand, ValueEnum};
+use wraith_core::auth::keys::KeySource;
+use wraith_core::client::{ConnectOptions, TransportMode};
+use wraith_core::transport::TcpTransport;
+#[cfg(feature = "tls")]
+use wraith_core::transport::TlsTransport;
+#[cfg(feature = "iroh")]
+use wraith_core::transport::IrohTransport;
+use wraith_core::transport::Transport;
+
+#[derive(Parser)]
+#[command(name = "wraith", version, about = "Wraith SSH tunnel client")]
+struct Cli {
+    #[command(subcommand)]
+    command: Commands,
+}
+
+#[derive(Subcommand)]
+enum Commands {
+    #[command(about = "Connect to a wraith server and start a SOCKS5 proxy / port forwarding session")]
+    Connect {
+        #[arg(long, help = "TCP/TLS server address (required for tcp/tls transport)", env = "WRAITH_SERVER")]
+        server: Option<String>,
+
+        #[arg(long, help = "iroh endpoint ID, base58-encoded (required for iroh transport)")]
+        peer: Option<String>,
+
+        #[arg(long, value_enum, default_value = "tcp", help = "Transport mode")]
+        transport: TransportModeArg,
+
+        #[arg(long, help = "SSH private key path", env = "WRAITH_IDENTITY")]
+        identity: Option<String>,
+
+        #[arg(long, default_value = "127.0.0.1:1080", help = "SOCKS5 listen address")]
+        socks5: String,
+
+        #[arg(long, action = clap::ArgAction::Append, help = "Port forward spec (repeatable, e.g. 5432:db:5432)")]
+        forward: Vec<String>,
+
+        #[arg(long, action = clap::ArgAction::Append, help = "Remote port forward spec (repeatable)")]
+        remote_forward: Vec<String>,
+
+        #[arg(long, help = "Upstream proxy URL (socks5:// or http://)")]
+        proxy: Option<String>,
+
+        #[arg(long, help = "iroh relay URL")]
+        iroh_relay: Option<String>,
+
+        #[arg(long, help = "SNI hostname for TLS")]
+        tls_server_name: Option<String>,
+
+        #[arg(long, help = "Accept self-signed TLS certs")]
+        insecure: bool,
+    },
+}
+
+#[derive(Clone, Debug, ValueEnum)]
+enum TransportModeArg {
+    Tcp,
+    Tls,
+    Iroh,
+}
+
+impl From<TransportModeArg> for TransportMode {
+    fn from(val: TransportModeArg) -> Self {
+        match val {
+            TransportModeArg::Tcp => TransportMode::Tcp,
+            TransportModeArg::Tls => TransportMode::Tls,
+            TransportModeArg::Iroh => TransportMode::Iroh,
+        }
+    }
+}
+
+#[tokio::main]
+async fn main() {
+    if let Err(e) = run().await {
+        eprintln!("error: {e}");
+        process::exit(1);
+    }
+}
+
+async fn run() -> Result<()> {
+    let cli = Cli::parse();
+
+    match cli.command {
+        Commands::Connect {
+            server,
+            peer,
+            transport,
+            identity,
+            socks5,
+            forward,
+            remote_forward,
+            proxy,
+            iroh_relay,
+            tls_server_name,
+            insecure,
+        } => {
+            let identity_val = identity
+                .ok_or_else(|| anyhow!("--identity is required (or set WRAITH_IDENTITY env var)"))?;
+            let key_source = KeySource::File(identity_val.into());
+
+            let transport_mode: TransportMode = transport.into();
+
+            if proxy.is_some() && matches!(transport_mode, TransportMode::Tcp) {
+                eprintln!("warning: --proxy with --transport tcp is effectively a no-op (TCP transport is already a direct connection); use the SOCKS5 server instead");
+            }
+
+            let mut opts = ConnectOptions::new(key_source)
+                .transport_mode(transport_mode.clone())
+                .socks5_addr(&socks5);
+
+            if let Some(ref s) = server {
+                opts = opts.server(s);
+            }
+            if let Some(ref p) = peer {
+                opts = opts.peer(p);
+            }
+            for fwd in &forward {
+                opts = opts.forward(fwd);
+            }
+            for rfwd in &remote_forward {
+                opts = opts.remote_forward(rfwd);
+            }
+            if let Some(ref p) = proxy {
+                opts = opts.proxy(p);
+            }
+            if let Some(ref r) = iroh_relay {
+                opts = opts.iroh_relay(r);
+            }
+            if let Some(ref n) = tls_server_name {
+                opts = opts.tls_server_name(n);
+            }
+            if insecure {
+                opts = opts.insecure(true);
+            }
+
+            opts.validate().map_err(|e| anyhow!("{e}"))?;
+
+            match transport_mode {
+                TransportMode::Tcp => {
+                    let addr: SocketAddr = server
+                        .as_deref()
+                        .ok_or_else(|| anyhow!("--server is required for tcp transport"))?
+                        .parse()
+                        .map_err(|e| anyhow!("invalid server address: {e}"))?;
+                    let t = Arc::new(TcpTransport::new(addr));
+                    connect_and_run(opts, t).await
+                }
+                TransportMode::Tls => {
+                    #[cfg(not(feature = "tls"))]
+                    {
+                        return Err(anyhow!("TLS transport is not available (wraith-core built without 'tls' feature)"));
+                    }
+                    #[cfg(feature = "tls")]
+                    {
+                        let addr: SocketAddr = server
+                            .as_deref()
+                            .ok_or_else(|| anyhow!("--server is required for tls transport"))?
+                            .parse()
+                            .map_err(|e| anyhow!("invalid server address: {e}"))?;
+                        let mut t = TlsTransport::new(addr);
+                        if let Some(ref n) = tls_server_name {
+                            t = t.with_server_name(n);
+                        }
+                        t = t.with_insecure(insecure);
+                        let t = Arc::new(t);
+                        connect_and_run(opts, t).await
+                    }
+                }
+                TransportMode::Iroh => {
+                    #[cfg(not(feature = "iroh"))]
+                    {
+                        return Err(anyhow!("iroh transport is not available (wraith-core built without 'iroh' feature)"));
+                    }
+                    #[cfg(feature = "iroh")]
+                    {
+                        use iroh::{NodeId, RelayUrl};
+                        let node_id_str = peer
+                            .as_deref()
+                            .ok_or_else(|| anyhow!("--peer is required for iroh transport"))?;
+                        let node_id: NodeId = node_id_str
+                            .parse()
+                            .map_err(|e| anyhow!("invalid iroh peer endpoint ID: {e}"))?;
+                        let relay_url: Option<RelayUrl> = match iroh_relay.as_deref() {
+                            Some(u) => Some(
+                                u.parse()
+                                    .map_err(|e| anyhow!("invalid iroh relay URL: {e}"))?,
+                            ),
+                            None => None,
+                        };
+                        let proxy_url: Option<url::Url> = match proxy.as_deref() {
+                            Some(u) => Some(
+                                u.parse()
+                                    .map_err(|e| anyhow!("invalid proxy URL: {e}"))?,
+                            ),
+                            None => None,
+                        };
+                        let t = Arc::new(
+                            IrohTransport::new(node_id, relay_url, proxy_url)
+                                .await
+                                .map_err(|e| anyhow!("failed to create iroh transport: {e}"))?,
+                        );
+                        connect_and_run(opts, t).await
+                    }
+                }
+            }
+        }
+    }
+}
+
+async fn connect_and_run<T: Transport>(opts: ConnectOptions, transport: Arc<T>) -> Result<()> {
+    wraith_core::client::ClientSession::new(opts, transport)
+        .await
+        .map_err(|e| anyhow!("{e}"))?
+        .run()
+        .await
+        .map_err(|e| anyhow!("{e}"))
+}