Add command line argument for signature verification key

crates/rrg/Cargo.toml

@@ -130,3 +130,12 @@ features = [
     "Win32_Foundation",
     "Win32_Storage_FileSystem",
 ]
+
+[dependencies.ed25519-dalek]
+version = "2.1.1"
+features = [
+    "rand_core",
+]
+
+[dependencies.hex]
+version = "0.4.3"

crates/rrg/src/args.rs

@@ -49,6 +49,14 @@ pub struct Args {
            arg_name="PATH",
            description="whether to log to a file")]
     pub log_to_file: Option<std::path::PathBuf>,
+
+    /// The public key for verfying signed commands.
+    #[argh(option,
+       long="command-verification-key",
+       arg_name="KEY",
+       description="verification key for signed commands",
+       from_str_fn(parse_verfication_key))]
+    pub command_verification_key: Option<ed25519_dalek::VerifyingKey>,
 }
 
 /// Parses command-line arguments.
@@ -66,3 +74,10 @@ pub fn from_env_args() -> Args {
 fn parse_duration(value: &str) -> Result<Duration, String> {
     humantime::parse_duration(value).map_err(|error| error.to_string())
 }
+
+/// Parses a ed25519 verification key from hex data given as string to a `VerifyingKey` object.
+fn parse_verfication_key(key: &str) -> Result<ed25519_dalek::VerifyingKey, String> {
+    let bytes = hex::decode(key).map_err(|error| error.to_string())?;
+    ed25519_dalek::VerifyingKey::try_from(&bytes[..])
+       .map_err(|error| error.to_string())
+}

crates/rrg/src/session/fake.rs

@@ -23,6 +23,7 @@ impl FakeSession {
     pub fn new() -> FakeSession {
         FakeSession::with_args(crate::args::Args {
             heartbeat_rate: std::time::Duration::from_secs(0),
+            command_verification_key: Some(ed25519_dalek::SigningKey::generate(&mut rand::rngs::OsRng).verifying_key()),
             verbosity: log::LevelFilter::Debug,
             log_to_stdout: false,
             log_to_file: None,