Add WASI SSH CLI and in-process Git SSH transport

userland/ssh/src/main.rs

@@ -0,0 +1,54 @@
+//! One noninteractive SSH command with host-mediated authentication.
+use clap::Parser;
+use std::{
+    io::{self, Read, Write},
+    time::{Duration, Instant},
+};
+#[derive(Parser)]
+struct Args {
+    #[arg(short = 'p', default_value_t = 22)]
+    port: u16,
+    #[arg(short = 'l')]
+    user: Option<String>,
+    #[arg(short = 'o')]
+    options: Vec<String>,
+    host: String,
+    #[arg(required = true, trailing_var_arg = true)]
+    command: Vec<String>,
+}
+fn run(args: Args) -> io::Result<u32> {
+    let mut accept_new = false;
+    for option in args.options {
+        match option.as_str() {
+            "StrictHostKeyChecking=accept-new" => accept_new = true,
+            "StrictHostKeyChecking=yes" => accept_new = false,
+            _ => return Err(io::Error::other("unsupported SSH option")),
+        }
+    }
+    let (user, host) = match args.host.split_once('@') {
+        Some((user, host)) => (Some(user), host),
+        None => (args.user.as_deref(), args.host.as_str()),
+    };
+    let session = sausage_ssh::identity::connect(host, args.port, user, accept_new)?;
+    let mut input = Vec::new();
+    io::stdin().read_to_end(&mut input)?;
+    let output = session.execute_input(
+        args.command.join(" ").as_bytes(),
+        &input,
+        usize::MAX,
+        Instant::now() + Duration::from_secs(300),
+    )?;
+    io::stdout().write_all(&output.stdout)?;
+    io::stderr().write_all(&output.stderr)?;
+    Ok(output.exit_code.unwrap_or(255))
+}
+fn main() {
+    let status = match run(Args::parse()) {
+        Ok(status) => status,
+        Err(error) => {
+            eprintln!("{error}");
+            255
+        }
+    };
+    std::process::exit(status.min(255) as i32);
+}