added connected command

src/cli.rs

@@ -90,3 +90,7 @@ pub fn add_key_to_luks(conf: &Config) -> Fido2LuksResult<u8> {
     let slot = handle.add_keyslot(&secret, None, None)?;
     Ok(slot)
 }
+
+pub fn authenticator_connected() -> Fido2LuksResult<bool> {
+    Ok(!device::get_devices()?.is_empty())
+}

src/device.rs

@@ -2,7 +2,7 @@ use crate::error::*;
 
 use ctap;
 use ctap::extensions::hmac::{FidoHmacCredential, HmacExtension};
-use ctap::FidoDevice;
+use ctap::{FidoDevice, FidoError, FidoErrorKind};
 
 pub fn perform_challenge(credential_id: &str, salt: &[u8; 32]) -> Fido2LuksResult<[u8; 32]> {
     let cred = FidoHmacCredential {
@@ -10,16 +10,34 @@ pub fn perform_challenge(credential_id: &str, salt: &[u8; 32]) -> Fido2LuksResul
         rp_id: "hmac".to_string(),
     };
     let mut errs = Vec::new();
-    for di in ctap::get_devices()? {
-        let mut dev = FidoDevice::new(&di)?;
-        match dev.hmac_challange(&cred, &salt[..]) {
-            Ok(secret) => {
-                return Ok(secret);
-            }
-            Err(e) => {
-                errs.push(e);
+    match get_devices()? {
+        ref devs if devs.is_empty() => Err(Fido2LuksError::NoAuthenticatorError)?,
+        devs => {
+            for mut dev in devs.into_iter() {
+                match dev.hmac_challange(&cred, &salt[..]) {
+                    Ok(secret) => {
+                        return Ok(secret);
+                    }
+                    Err(e) => {
+                        errs.push(e);
+                    }
+                }
             }
         }
     }
     Err(errs.pop().ok_or(Fido2LuksError::NoAuthenticatorError)?)?
 }
+
+pub fn get_devices() -> Fido2LuksResult<Vec<FidoDevice>> {
+    let mut devices = Vec::with_capacity(2);
+    for di in ctap::get_devices()? {
+        match FidoDevice::new(&di) {
+            Err(e) => match e.kind() {
+                FidoErrorKind::ParseCtap | FidoErrorKind::DeviceUnsupported => (),
+                err => Err(FidoError::from(err))?,
+            },
+            Ok(dev) => devices.push(dev),
+        }
+    }
+    Ok(devices)
+}

src/main.rs

@@ -1,6 +1,5 @@
 #[macro_use]
 extern crate failure;
-#[macro_use]
 extern crate serde_derive;
 use crate::cli::*;
 use crate::config::*;
@@ -20,6 +19,7 @@ use std::env;
 
 use std::io::{self, Write};
 use std::path::PathBuf;
+use std::process::exit;
 
 mod cli;
 mod config;
@@ -104,8 +104,18 @@ fn main() -> Fido2LuksResult<()> {
         match args.first().map(|s| s.as_ref()).unwrap() {
             "addkey" => add_key_to_luks(&Config::load_default_location()?).map(|_| ()),
             "setup" => setup(),
+            "connected" => match authenticator_connected()? {
+                false => {
+                    println!("no");
+                    exit(1)
+                }
+                _ => {
+                    println!("yes");
+                    exit(0)
+                }
+            },
             _ => {
-                eprintln!("Usage: setup | addkey");
+                eprintln!("Usage: setup | addkey | connected");
                 Ok(())
             } //"selfcontain" => package_self()
         }