Improve Windows client parity

Cargo.lock

@@ -463,6 +463,7 @@ dependencies = [
  "tokio",
  "toml",
  "vt100",
+ "windows-sys 0.59.0",
  "x25519-dalek",
 ]
 

Cargo.toml

@@ -31,6 +31,9 @@ toml = "0.8"
 vt100 = "0.15"
 x25519-dalek = { version = "2.0.1", features = ["static_secrets", "getrandom"] }
 
+[target.'cfg(windows)'.dependencies]
+windows-sys = { version = "0.59", features = ["Win32_Foundation", "Win32_System_Console"] }
+
 [dev-dependencies]
 tempfile = "3.14"
 

src/bin/dosh-client.rs

@@ -9929,7 +9929,22 @@ fn flush_local_terminal_input() {
     }
 }
 
-#[cfg(not(unix))]
+#[cfg(windows)]
+fn flush_local_terminal_input() {
+    unsafe {
+        use windows_sys::Win32::Foundation::INVALID_HANDLE_VALUE;
+        use windows_sys::Win32::System::Console::{
+            FlushConsoleInputBuffer, GetStdHandle, STD_INPUT_HANDLE,
+        };
+
+        let handle = GetStdHandle(STD_INPUT_HANDLE);
+        if !handle.is_null() && handle != INVALID_HANDLE_VALUE {
+            let _ = FlushConsoleInputBuffer(handle);
+        }
+    }
+}
+
+#[cfg(all(not(unix), not(windows)))]
 fn flush_local_terminal_input() {}
 
 #[cfg(unix)]
@@ -9954,7 +9969,12 @@ fn drain_local_terminal_input() {
     }
 }
 
-#[cfg(not(unix))]
+#[cfg(windows)]
+fn drain_local_terminal_input() {
+    flush_local_terminal_input();
+}
+
+#[cfg(all(not(unix), not(windows)))]
 fn drain_local_terminal_input() {}
 
 impl Drop for RawMode {

src/ssh_agent.rs

@@ -1,31 +1,28 @@
 use crate::native::{ForwardingRequest, NativeClientHello, NativeServerHello, NativeUserAuth};
-#[cfg(unix)]
 use crate::native::{
     is_supported_user_key_algorithm, parse_ssh_ed25519_public_blob, user_auth_transcript,
 };
-#[cfg(unix)]
 use anyhow::{Context, bail};
 use anyhow::{Result, anyhow};
-#[cfg(unix)]
+#[cfg(windows)]
+use std::fs::OpenOptions;
 use std::io::{Read, Write};
 #[cfg(unix)]
 use std::os::unix::net::UnixStream;
 use std::path::Path;
 
-#[cfg(unix)]
 const SSH_AGENT_FAILURE: u8 = 5;
-#[cfg(unix)]
 const SSH2_AGENTC_REQUEST_IDENTITIES: u8 = 11;
-#[cfg(unix)]
 const SSH2_AGENT_IDENTITIES_ANSWER: u8 = 12;
-#[cfg(unix)]
 const SSH2_AGENTC_SIGN_REQUEST: u8 = 13;
-#[cfg(unix)]
 const SSH2_AGENT_SIGN_RESPONSE: u8 = 14;
-#[cfg(unix)]
 const SSH_AGENT_RSA_SHA2_512: u32 = 4;
-#[cfg(unix)]
 const MAX_AGENT_PACKET: usize = 256 * 1024;
+#[cfg(windows)]
+const WINDOWS_OPENSSH_AGENT_PIPE: &str = r"\\.\pipe\openssh-ssh-agent";
+
+trait AgentStream: Read + Write {}
+impl<T: Read + Write> AgentStream for T {}
 
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct AgentIdentity {
@@ -47,7 +44,21 @@ pub fn sign_user_auth_with_agent(
     sign_user_auth_with_agent_at(sock, client, server, requested_forwardings)
 }
 
-#[cfg(not(unix))]
+#[cfg(windows)]
+pub fn sign_user_auth_with_agent(
+    client: &NativeClientHello,
+    server: &NativeServerHello,
+    requested_forwardings: Vec<ForwardingRequest>,
+) -> Result<NativeUserAuth> {
+    sign_user_auth_with_agent_at(
+        WINDOWS_OPENSSH_AGENT_PIPE,
+        client,
+        server,
+        requested_forwardings,
+    )
+}
+
+#[cfg(not(any(unix, windows)))]
 pub fn sign_user_auth_with_agent(
     _client: &NativeClientHello,
     _server: &NativeServerHello,
@@ -67,23 +78,30 @@ pub fn sign_user_auth_with_agent_at(
 ) -> Result<NativeUserAuth> {
     let mut agent = UnixStream::connect(socket_path.as_ref())
         .with_context(|| format!("connect ssh-agent {}", socket_path.as_ref().display()))?;
-    let identities = request_supported_identities(&mut agent)?;
-    let identity = identities
-        .first()
-        .ok_or_else(|| anyhow!("ssh-agent has no supported identities"))?;
-    let mut auth = NativeUserAuth {
-        public_key_algorithm: identity.sign_algorithm.clone(),
-        public_key: identity.public_key.clone(),
-        signature: Vec::new(),
-        requested_forwardings,
-    };
-    let transcript = user_auth_transcript(client, server, &auth)?;
-    auth.signature = sign_with_agent(&mut agent, identity, &transcript)
-        .with_context(|| format!("ssh-agent sign with {}", identity.comment))?;
-    Ok(auth)
+    sign_user_auth_with_agent_stream(&mut agent, client, server, requested_forwardings)
 }
 
-#[cfg(not(unix))]
+#[cfg(windows)]
+pub fn sign_user_auth_with_agent_at(
+    pipe_path: impl AsRef<Path>,
+    client: &NativeClientHello,
+    server: &NativeServerHello,
+    requested_forwardings: Vec<ForwardingRequest>,
+) -> Result<NativeUserAuth> {
+    let mut agent = OpenOptions::new()
+        .read(true)
+        .write(true)
+        .open(pipe_path.as_ref())
+        .with_context(|| {
+            format!(
+                "connect Windows OpenSSH agent pipe {}",
+                pipe_path.as_ref().display()
+            )
+        })?;
+    sign_user_auth_with_agent_stream(&mut agent, client, server, requested_forwardings)
+}
+
+#[cfg(not(any(unix, windows)))]
 pub fn sign_user_auth_with_agent_at(
     _socket_path: impl AsRef<Path>,
     _client: &NativeClientHello,
@@ -95,8 +113,29 @@ pub fn sign_user_auth_with_agent_at(
     ))
 }
 
-#[cfg(unix)]
-fn request_supported_identities(agent: &mut UnixStream) -> Result<Vec<AgentIdentity>> {
+fn sign_user_auth_with_agent_stream(
+    agent: &mut impl AgentStream,
+    client: &NativeClientHello,
+    server: &NativeServerHello,
+    requested_forwardings: Vec<ForwardingRequest>,
+) -> Result<NativeUserAuth> {
+    let identities = request_supported_identities(agent)?;
+    let identity = identities
+        .first()
+        .ok_or_else(|| anyhow!("ssh-agent has no supported identities"))?;
+    let mut auth = NativeUserAuth {
+        public_key_algorithm: identity.sign_algorithm.clone(),
+        public_key: identity.public_key.clone(),
+        signature: Vec::new(),
+        requested_forwardings,
+    };
+    let transcript = user_auth_transcript(client, server, &auth)?;
+    auth.signature = sign_with_agent(agent, identity, &transcript)
+        .with_context(|| format!("ssh-agent sign with {}", identity.comment))?;
+    Ok(auth)
+}
+
+fn request_supported_identities(agent: &mut impl AgentStream) -> Result<Vec<AgentIdentity>> {
     write_agent_packet(agent, &[SSH2_AGENTC_REQUEST_IDENTITIES])?;
     let payload = read_agent_packet(agent)?;
     let mut cursor = payload.as_slice();
@@ -122,7 +161,6 @@ fn request_supported_identities(agent: &mut UnixStream) -> Result<Vec<AgentIdent
     Ok(identities)
 }
 
-#[cfg(unix)]
 fn supported_identity(key_blob: Vec<u8>, comment: String) -> Result<Option<AgentIdentity>> {
     let algorithm = key_blob_algorithm(&key_blob)?;
     if !is_supported_user_key_algorithm(&algorithm) {
@@ -158,9 +196,8 @@ fn supported_identity(key_blob: Vec<u8>, comment: String) -> Result<Option<Agent
     Ok(Some(identity))
 }
 
-#[cfg(unix)]
 fn sign_with_agent(
-    agent: &mut UnixStream,
+    agent: &mut impl AgentStream,
     identity: &AgentIdentity,
     transcript: &[u8],
 ) -> Result<Vec<u8>> {
@@ -203,8 +240,7 @@ fn sign_with_agent(
     Ok(signature.to_vec())
 }
 
-#[cfg(unix)]
-fn read_agent_packet(stream: &mut UnixStream) -> Result<Vec<u8>> {
+fn read_agent_packet(stream: &mut impl AgentStream) -> Result<Vec<u8>> {
     let mut len = [0u8; 4];
     stream
         .read_exact(&mut len)
@@ -218,8 +254,7 @@ fn read_agent_packet(stream: &mut UnixStream) -> Result<Vec<u8>> {
     Ok(payload)
 }
 
-#[cfg(unix)]
-fn write_agent_packet(stream: &mut UnixStream, payload: &[u8]) -> Result<()> {
+fn write_agent_packet(stream: &mut impl AgentStream, payload: &[u8]) -> Result<()> {
     anyhow::ensure!(
         payload.len() <= MAX_AGENT_PACKET,
         "ssh-agent request too large"
@@ -229,7 +264,6 @@ fn write_agent_packet(stream: &mut UnixStream, payload: &[u8]) -> Result<()> {
     Ok(())
 }
 
-#[cfg(unix)]
 fn read_u8(cursor: &mut &[u8]) -> Result<u8> {
     anyhow::ensure!(!cursor.is_empty(), "truncated u8");
     let value = cursor[0];
@@ -237,7 +271,6 @@ fn read_u8(cursor: &mut &[u8]) -> Result<u8> {
     Ok(value)
 }
 
-#[cfg(unix)]
 fn read_u32(cursor: &mut &[u8]) -> Result<u32> {
     anyhow::ensure!(cursor.len() >= 4, "truncated u32");
     let value = u32::from_be_bytes(cursor[..4].try_into().unwrap());
@@ -245,7 +278,6 @@ fn read_u32(cursor: &mut &[u8]) -> Result<u32> {
     Ok(value)
 }
 
-#[cfg(unix)]
 fn read_ssh_string<'a>(cursor: &mut &'a [u8]) -> Result<&'a [u8]> {
     let len = read_u32(cursor)? as usize;
     anyhow::ensure!(cursor.len() >= len, "truncated SSH string");
@@ -254,13 +286,11 @@ fn read_ssh_string<'a>(cursor: &mut &'a [u8]) -> Result<&'a [u8]> {
     Ok(value)
 }
 
-#[cfg(unix)]
 fn write_ssh_string(out: &mut Vec<u8>, value: &[u8]) {
     out.extend_from_slice(&(value.len() as u32).to_be_bytes());
     out.extend_from_slice(value);
 }
 
-#[cfg(unix)]
 fn key_blob_algorithm(blob: &[u8]) -> Result<String> {
     let mut cursor = blob;
     let algorithm = read_ssh_string(&mut cursor)?;