feat(cli): improvements to outputs & bind options

It is now possible to specify the host and port the SSH server listens
to using CLI arguments. Also improved host key naming and some inline
strings within the CLI version menu.

.gitignore

@@ -1,3 +1,2 @@
 /target
 .data/*.log
-*.pem*

Cargo.lock

@@ -3434,6 +3434,7 @@ dependencies = [
  "directories",
  "futures",
  "human-panic",
+ "indoc",
  "json5",
  "lazy_static",
  "libc",
@@ -3443,6 +3444,7 @@ dependencies = [
  "serde",
  "serde_json",
  "signal-hook",
+ "ssh-key",
  "strip-ansi-escapes",
  "strum",
  "tokio",

Cargo.toml

@@ -26,6 +26,7 @@ derive_deref = "1.1.1"
 directories = "5.0.1"
 futures = "0.3.31"
 human-panic = "2.0.2"
+indoc = "2.0.5"
 json5 = "0.4.1"
 lazy_static = "1.5.0"
 libc = "0.2.161"
@@ -45,4 +46,5 @@ tracing-subscriber = { version = "0.3.18", features = ["env-filter", "serde"] }
 
 [build-dependencies]
 anyhow = "1.0.90"
+ssh-key = { version = "0.6.7", features = ["getrandom", "crypto"] }
 vergen-gix = { version = "1.0.2", features = ["build", "cargo"] }

build.rs

@@ -1,7 +1,43 @@
+use std::{env, path::PathBuf};
+
 use anyhow::Result;
+use ssh_key::{rand_core, Algorithm, EcdsaCurve, LineEnding, PrivateKey};
 use vergen_gix::{BuildBuilder, CargoBuilder, Emitter, GixBuilder};
 
+const SSH_KEY_ALGOS: &[(&'static str, Algorithm)] = &[
+    ("rsa.pem", Algorithm::Rsa { hash: None }),
+    ("ed25519.pem", Algorithm::Ed25519),
+    ("ecdsa.pem", Algorithm::Ecdsa {
+        curve: EcdsaCurve::NistP256,
+    }),
+];
+
 fn main() -> Result<()> {
+    println!("cargo:rerun-if-changed=build.rs");
+
+    // Generate openSSH host keys
+    let mut rng = rand_core::OsRng::default();
+    let keys = SSH_KEY_ALGOS
+        .iter()
+        .map(|(file_name, algo)| (*file_name, PrivateKey::random(&mut rng, algo.to_owned()).map_err(anyhow::Error::from)))
+        .collect::<Vec<(&str, Result<PrivateKey>)>>();
+
+    let out_dir = PathBuf::from(env::var("OUT_DIR").unwrap());
+    for (file_name, key_res) in keys {
+        if let Ok(ref key) = key_res {
+            let path = out_dir.join(file_name);
+            if path.exists() {
+                println!("cargo:warning=Skipping existing host key: {:?}", path.file_stem());
+                continue;
+            }
+            
+            key.write_openssh_file(&path, LineEnding::default())?;
+        } else {
+            println!("cargo:warning=Failed to generate host key: {:?}", key_res);
+        }
+    }
+
+    // Emit the build information
     let build = BuildBuilder::all_build()?;
     let gix = GixBuilder::all_git()?;
     let cargo = CargoBuilder::all_cargo()?;

src/cli.rs

@@ -1,4 +1,5 @@
 use clap::Parser;
+use indoc::formatdoc;
 
 use crate::config::{get_config_dir, get_data_dir};
 
@@ -12,6 +13,13 @@ pub struct Cli {
     /// Frame rate, i.e. number of frames per second
     #[arg(short, long, value_name = "FLOAT", default_value_t = 60.0)]
     pub frame_rate: f64,
+
+    /// The host address to start the SSH server on
+    #[arg(short = 'H', long, value_name = "ADDRESS", default_value_t = String::from("127.0.0.1"))]
+    pub host: String,
+    /// The port to start the SSH server on
+    #[arg(short, long, value_name = "PORT", default_value_t = 2222)]
+    pub port: u16,
 }
 
 const VERSION_MESSAGE: &str = concat!(
@@ -30,13 +38,12 @@ pub fn version() -> String {
     let config_dir_path = get_config_dir().display().to_string();
     let data_dir_path = get_data_dir().display().to_string();
 
-    format!(
+    formatdoc! {"
-        "\
+        {VERSION_MESSAGE}
-{VERSION_MESSAGE}
 
-Authors: {author}
+        Authors: {author}
 
-Config directory: {config_dir_path}
+        Config directory: {config_dir_path}
-Data directory: {data_dir_path}"
+        Data directory: {data_dir_path}
-    )
+    "}
 }

src/keycode.rs

@@ -110,6 +110,7 @@ impl KeyCodeExt for KeyCode {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use pretty_assertions::assert_eq;
 
     #[test]
     fn test_keycode_from_control_chars() {

src/main.rs

@@ -24,23 +24,42 @@ mod ssh;
 mod tui;
 
 const SSH_KEYS: &[&[u8]] = &[
-    include_bytes!("../rsa.pem"),
+    include_bytes!(concat!(env!("OUT_DIR"), "/rsa.pem")),
-    include_bytes!("../ed25519.pem"),
+    include_bytes!(concat!(env!("OUT_DIR"), "/ecdsa.pem")),
+    include_bytes!(concat!(env!("OUT_DIR"), "/ed25519.pem")),
 ];
 lazy_static! {
     pub(crate) static ref OPTIONS: Cli = Cli::parse();
-    pub(crate) static ref SOCKET_ADDR: SocketAddr = SocketAddr::from(([127, 0, 0, 1], 2222));
+    pub(crate) static ref SOCKET_ADDR: Option<SocketAddr> = Some(SocketAddr::from((
+        // Convert the hostname IP to a fixed size array of [u8; 4]
+        TryInto::<[u8; 4]>::try_into(
+            OPTIONS
+                .host
+                .splitn(4, ".")
+                .map(|octet_str| u8::from_str_radix(octet_str, 10)
+                    .map_err(|_| eyre!("Octet component out of range (expected u8)")))
+                .collect::<Result<Vec<u8>>>()
+                .ok()?
+        )
+        .ok()?,
+
+        // The port to listen on
+        OPTIONS.port
+    )));
 }
 
 #[tokio::main]
 async fn main() -> Result<()> {
     crate::errors::init()?;
     crate::logging::init()?;
+    let _ = *OPTIONS; // force clap to run by evaluating it
 
+    let socket_addr = SOCKET_ADDR.ok_or(eyre!("Invalid host IP provided"))?;
     let config = ssh_config();
-    tracing::info!("Attempting to listen on {}", *SOCKET_ADDR);
+
+    tracing::info!("Attempting to listen on {}", socket_addr);
     SshServer::default()
-        .run_on_socket(Arc::new(config), &TcpListener::bind(*SOCKET_ADDR).await?)
+        .run_on_socket(Arc::new(config), &TcpListener::bind(socket_addr).await?)
         .await
         .map_err(|err| eyre!(err))
 }