Add WASI SSH CLI and in-process Git SSH transport

userland/git/src/ssh.rs

@@ -0,0 +1,63 @@
+//! Git exec channels over the shared SSH library, with host-mediated signing.
+use crate::{Result, repo::error};
+use gix::bstr::ByteSlice;
+use std::io;
+fn parse(input: &str) -> io::Result<gix::Url> {
+    let url = gix::url::parse(input.as_bytes().as_bstr())
+        .map_err(|_| io::Error::other("invalid SSH URL"))?;
+    if url.scheme != gix::url::Scheme::Ssh
+        || url.host.as_deref().is_none_or(str::is_empty)
+        || url.password.is_some()
+        || url.path.is_empty()
+        || url.path.iter().any(|b| matches!(b, 0 | b'\n' | b'\r'))
+    {
+        return Err(io::Error::other(
+            "use ssh://[user@]host[:port]/path or [user@]host:path without a password",
+        ));
+    }
+    Ok(url)
+}
+pub fn clean_url(input: &str) -> io::Result<String> {
+    if input.starts_with("http://") || input.starts_with("https://") {
+        crate::http::clean_url(input).map(|url| url.to_string())
+    } else {
+        parse(input)?;
+        Ok(input.into())
+    }
+}
+pub fn is_ssh(input: &str) -> bool {
+    !input.starts_with("http://") && !input.starts_with("https://")
+}
+pub type Connection =
+    gix_transport::client::git::blocking_io::Connection<sausage_ssh::Reader, sausage_ssh::Writer>;
+pub fn connection(input: &str, service: gix_transport::Service) -> Result<Connection> {
+    let url = parse(input).map_err(|e| error("SSH URL", e))?;
+    let host = url.host.as_deref().unwrap();
+    let mut session =
+        sausage_ssh::identity::connect(host, url.port.unwrap_or(22), url.user.as_deref(), false)
+            .map_err(|e| error("SSH", e))?;
+    let mut command = service.as_str().as_bytes().to_vec();
+    command.extend_from_slice(b" '");
+    for byte in url.path.iter() {
+        if *byte == b'\'' {
+            command.extend_from_slice(b"'\\''");
+        } else {
+            command.push(*byte);
+        }
+    }
+    command.push(b'\'');
+    session
+        .open_command(&command)
+        .map_err(|e| error("SSH exec", e))?;
+    let (read, write) = session.split();
+    Ok(Connection::new(
+        read,
+        write,
+        gix_transport::Protocol::V1,
+        url.path,
+        None::<(&str, Option<u16>)>,
+        gix_transport::client::git::ConnectMode::Process,
+        false,
+    )
+    .custom_url(Some(input.into())))
+}