feat: register works

.gitignore

@@ -1,3 +1,4 @@
+.idea/
 # ---> Rust
 # Generated by Cargo
 # will have compiled files and executables

Cargo.lock

@@ -1,5 +1,25 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
+[[package]]
+name = "ansi_term"
+version = "0.11.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ee49baf6cb617b853aa8d93bf420db2383fab46d314482ca2803b40d5fde979b"
+dependencies = [
+ "winapi",
+]
+
+[[package]]
+name = "atty"
+version = "0.2.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d9b39be18770d11421cdb1b9947a45dd3f37e93092cbf377614828a319d5fee8"
+dependencies = [
+ "hermit-abi",
+ "libc",
+ "winapi",
+]
+
 [[package]]
 name = "authenticator"
 version = "0.3.1"
@@ -12,23 +32,53 @@ dependencies = [
  "libc",
  "libudev",
  "log",
- "rand",
+ "rand 0.7.3",
  "runloop",
  "winapi",
 ]
 
+[[package]]
+name = "base64"
+version = "0.13.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "904dfeac50f3cdaba28fc6f57fdcddb75f49ed61346676a78c4ffe55877802fd"
+
 [[package]]
 name = "bitflags"
 version = "1.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "cf1de2fe8c75bc145a2f577add951f8134889b4795d47466a54a5c846d691693"
 
+[[package]]
+name = "block-buffer"
+version = "0.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4152116fd6e9dadb291ae18fc1ec3575ed6d84c29642d97890f4b4a3417297e4"
+dependencies = [
+ "generic-array",
+]
+
 [[package]]
 name = "cfg-if"
 version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
 
+[[package]]
+name = "clap"
+version = "2.33.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "37e58ac78573c40708d45522f0d80fa2f01cc4f9b4e2bf749807255454312002"
+dependencies = [
+ "ansi_term",
+ "atty",
+ "bitflags",
+ "strsim",
+ "textwrap",
+ "unicode-width",
+ "vec_map",
+]
+
 [[package]]
 name = "core-foundation"
 version = "0.9.1"
@@ -45,6 +95,15 @@ version = "0.8.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ea221b5284a47e40033bf9b66f35f984ec0ea2931eb03505246cd27a963f981b"
 
+[[package]]
+name = "cpufeatures"
+version = "0.1.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "66c99696f6c9dd7f35d486b9d04d7e6e202aa3e8c40d553f2fdf5e7e0c6a71ef"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "devd-rs"
 version = "0.3.1"
@@ -55,6 +114,46 @@ dependencies = [
  "nom",
 ]
 
+[[package]]
+name = "digest"
+version = "0.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d3dd60d1080a57a05ab032377049e0591415d2b31afd7028356dbf3cc6dcb066"
+dependencies = [
+ "generic-array",
+]
+
+[[package]]
+name = "dirs-next"
+version = "2.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b98cf8ebf19c3d1b223e151f99a4f9f0690dca41414773390fc824184ac833e1"
+dependencies = [
+ "cfg-if",
+ "dirs-sys-next",
+]
+
+[[package]]
+name = "dirs-sys-next"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4ebda144c4fe02d1f7ea1a7d9641b6fc6b580adcfa024ae48797ecdeb6825b4d"
+dependencies = [
+ "libc",
+ "redox_users",
+ "winapi",
+]
+
+[[package]]
+name = "generic-array"
+version = "0.14.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "501466ecc8a30d1d3b7fc9229b122b2ce8ed6e9d9223f1138d4babb253e51817"
+dependencies = [
+ "typenum",
+ "version_check",
+]
+
 [[package]]
 name = "getrandom"
 version = "0.1.16"
@@ -63,9 +162,41 @@ checksum = "8fc3cb4d91f53b50155bdcfd23f6a4c39ae1969c2ae85982b135750cccaf5fce"
 dependencies = [
  "cfg-if",
  "libc",
- "wasi",
+ "wasi 0.9.0+wasi-snapshot-preview1",
 ]
 
+[[package]]
+name = "getrandom"
+version = "0.2.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7fcd999463524c52659517fe2cea98493cfe485d10565e7b0fb07dbba7ad2753"
+dependencies = [
+ "cfg-if",
+ "libc",
+ "wasi 0.10.2+wasi-snapshot-preview1",
+]
+
+[[package]]
+name = "hermit-abi"
+version = "0.1.19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "62b467343b94ba476dcb2500d242dadbb39557df889310ac77c5d99100aaac33"
+dependencies = [
+ "libc",
+]
+
+[[package]]
+name = "itoa"
+version = "0.4.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dd25036021b0de88a0aff6b850051563c6516d0bf53f8638938edbb9de732736"
+
+[[package]]
+name = "lazy_static"
+version = "1.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
+
 [[package]]
 name = "libc"
 version = "0.2.97"
@@ -117,6 +248,12 @@ dependencies = [
  "version_check",
 ]
 
+[[package]]
+name = "opaque-debug"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "624a8340c38c1b80fd549087862da4ba43e08858af025b236e509b6649fc13d5"
+
 [[package]]
 name = "pkg-config"
 version = "0.3.19"
@@ -129,17 +266,47 @@ version = "0.2.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ac74c624d6b2d21f425f752262f42188365d7b8ff1aff74c82e45136510a4857"
 
+[[package]]
+name = "proc-macro2"
+version = "1.0.27"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f0d8caf72986c1a598726adc988bb5984792ef84f5ee5aa50209145ee8077038"
+dependencies = [
+ "unicode-xid",
+]
+
+[[package]]
+name = "quote"
+version = "1.0.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c3d0b9745dc2debf507c8422de05d7226cc1f0644216dfdfead988f9b1ab32a7"
+dependencies = [
+ "proc-macro2",
+]
+
 [[package]]
 name = "rand"
 version = "0.7.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6a6b1679d49b24bbfe0c803429aa1874472f50d9b363131f0e89fc356b544d03"
 dependencies = [
- "getrandom",
+ "getrandom 0.1.16",
  "libc",
- "rand_chacha",
+ "rand_chacha 0.2.2",
- "rand_core",
+ "rand_core 0.5.1",
- "rand_hc",
+ "rand_hc 0.2.0",
+]
+
+[[package]]
+name = "rand"
+version = "0.8.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2e7573632e6454cf6b99d7aac4ccca54be06da05aca2ef7423d22d27d4d4bcd8"
+dependencies = [
+ "libc",
+ "rand_chacha 0.3.1",
+ "rand_core 0.6.3",
+ "rand_hc 0.3.1",
 ]
 
 [[package]]
@@ -149,7 +316,17 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f4c8ed856279c9737206bf725bf36935d8666ead7aa69b52be55af369d193402"
 dependencies = [
  "ppv-lite86",
- "rand_core",
+ "rand_core 0.5.1",
+]
+
+[[package]]
+name = "rand_chacha"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e6c10a63a0fa32252be49d21e7709d4d4baf8d231c2dbce1eaa8141b9b127d88"
+dependencies = [
+ "ppv-lite86",
+ "rand_core 0.6.3",
 ]
 
 [[package]]
@@ -158,7 +335,16 @@ version = "0.5.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "90bde5296fc891b0cef12a6d03ddccc162ce7b2aff54160af9338f8d40df6d19"
 dependencies = [
- "getrandom",
+ "getrandom 0.1.16",
+]
+
+[[package]]
+name = "rand_core"
+version = "0.6.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d34f1408f55294453790c48b2f1ebbb1c5b4b7563eb1f418bcfcfdbb06ebb4e7"
+dependencies = [
+ "getrandom 0.2.3",
 ]
 
 [[package]]
@@ -167,7 +353,35 @@ version = "0.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ca3129af7b92a17112d59ad498c6f81eaf463253766b90396d39ea7a39d6613c"
 dependencies = [
- "rand_core",
+ "rand_core 0.5.1",
+]
+
+[[package]]
+name = "rand_hc"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d51e9f596de227fda2ea6c84607f5558e196eeaf43c986b724ba4fb8fdf497e7"
+dependencies = [
+ "rand_core 0.6.3",
+]
+
+[[package]]
+name = "redox_syscall"
+version = "0.2.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5ab49abadf3f9e1c4bc499e8845e152ad87d2ad2d30371841171169e9d75feee"
+dependencies = [
+ "bitflags",
+]
+
+[[package]]
+name = "redox_users"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "528532f3d801c87aec9def2add9ca802fe569e44a544afe633765267840abe64"
+dependencies = [
+ "getrandom 0.2.3",
+ "redox_syscall",
 ]
 
 [[package]]
@@ -176,6 +390,145 @@ version = "0.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5d79b4b604167921892e84afbbaad9d5ad74e091bf6c511d9dbfb0593f09fabd"
 
+[[package]]
+name = "rust_util"
+version = "0.6.40"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "38bab12142950cb1b14790648b024708f628908e90eeab1a1d38022fb3d52b2e"
+dependencies = [
+ "lazy_static",
+ "libc",
+ "term",
+ "term_size",
+]
+
+[[package]]
+name = "rustversion"
+version = "1.0.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "61b3909d758bb75c79f23d4736fac9433868679d3ad2ea7a61e3c25cfda9a088"
+
+[[package]]
+name = "ryu"
+version = "1.0.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "71d301d4193d031abdd79ff7e3dd721168a9572ef3fe51a1517aba235bd8f86e"
+
+[[package]]
+name = "serde"
+version = "1.0.126"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ec7505abeacaec74ae4778d9d9328fe5a5d04253220a85c4ee022239fc996d03"
+dependencies = [
+ "serde_derive",
+]
+
+[[package]]
+name = "serde_derive"
+version = "1.0.126"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "963a7dbc9895aeac7ac90e74f34a5d5261828f79df35cbed41e10189d3804d43"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "serde_json"
+version = "1.0.64"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "799e97dc9fdae36a5c8b8f2cae9ce2ee9fdce2058c57a93e6099d919fd982f79"
+dependencies = [
+ "itoa",
+ "ryu",
+ "serde",
+]
+
+[[package]]
+name = "sha2"
+version = "0.9.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b362ae5752fd2137731f9fa25fd4d9058af34666ca1966fb969119cc35719f12"
+dependencies = [
+ "block-buffer",
+ "cfg-if",
+ "cpufeatures",
+ "digest",
+ "opaque-debug",
+]
+
+[[package]]
+name = "strsim"
+version = "0.8.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8ea5119cdb4c55b55d432abb513a0429384878c15dde60cc77b1c99de1a95a6a"
+
+[[package]]
+name = "syn"
+version = "1.0.73"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f71489ff30030d2ae598524f61326b902466f72a0fb1a8564c001cc63425bcc7"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-xid",
+]
+
+[[package]]
+name = "term"
+version = "0.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c59df8ac95d96ff9bede18eb7300b0fda5e5d8d90960e76f8e14ae765eedbf1f"
+dependencies = [
+ "dirs-next",
+ "rustversion",
+ "winapi",
+]
+
+[[package]]
+name = "term_size"
+version = "0.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1e4129646ca0ed8f45d09b929036bafad5377103edd06e50bf574b353d2b08d9"
+dependencies = [
+ "libc",
+ "winapi",
+]
+
+[[package]]
+name = "textwrap"
+version = "0.11.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d326610f408c7a4eb6f51c37c330e496b08506c9457c9d34287ecc38809fb060"
+dependencies = [
+ "unicode-width",
+]
+
+[[package]]
+name = "typenum"
+version = "1.13.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "879f6906492a7cd215bfa4cf595b600146ccfac0c79bcbd1f3000162af5e8b06"
+
+[[package]]
+name = "unicode-width"
+version = "0.1.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9337591893a19b88d8d87f2cec1e73fad5cdfd10e5a6f349f498ad6ea2ffb1e3"
+
+[[package]]
+name = "unicode-xid"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8ccb82d61f80a663efe1f787a51b16b5a51e3314d6ac365b08639f52387b33f3"
+
+[[package]]
+name = "vec_map"
+version = "0.8.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f1bddf1187be692e79c5ffeab891132dfb0f236ed36a43c7ed39f1165ee20191"
+
 [[package]]
 name = "version_check"
 version = "0.9.3"
@@ -188,11 +541,24 @@ version = "0.9.0+wasi-snapshot-preview1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "cccddf32554fecc6acb585f82a32a72e28b48f8c4c1883ddfeeeaa96f7d8e519"
 
+[[package]]
+name = "wasi"
+version = "0.10.2+wasi-snapshot-preview1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fd6fbd9a79829dd1ad0cc20627bf1ed606756a7f77edff7b66b7064f9cb327c6"
+
 [[package]]
 name = "webauthn-cli"
 version = "0.1.0"
 dependencies = [
  "authenticator",
+ "base64",
+ "clap",
+ "rand 0.8.4",
+ "rust_util",
+ "serde",
+ "serde_json",
+ "sha2",
 ]
 
 [[package]]

Cargo.toml

@@ -7,5 +7,11 @@ edition = "2018"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-authenticator = "0.3.1"
+authenticator = "0.3"
-
+clap = "2.33"
+rust_util = "0.6"
+sha2 = "0.9"
+rand = "0.8"
+base64 = "0.13"
+serde = { version = "1.0", features = ["derive"] }
+serde_json = "1.0"

src/cmd.rs

@@ -0,0 +1,26 @@
+use clap::{ArgMatches, App, Arg};
+use rust_util::XResult;
+
+pub type CommandError = XResult<()>;
+
+pub trait Command {
+    fn name(&self) -> &str;
+    fn subcommand<'a>(&self) -> App<'a, 'a>;
+    fn run(&self, arg_matches: &ArgMatches, _: &ArgMatches) -> CommandError;
+}
+
+
+pub struct DefaultCommandImpl;
+
+impl DefaultCommandImpl {
+    pub fn process_command<'a>(app: App<'a, 'a>) -> App<'a, 'a> {
+        app.arg(Arg::with_name("verbose").long("verbose").short("v").multiple(true).help("Show verbose info"))
+    }
+    pub fn run(arg_matches: &ArgMatches) -> CommandError {
+        let verbose_count = arg_matches.occurrences_of("verbose");
+        information!("Verbose count: {}", verbose_count);
+        information!("This is default command cli ...");
+        // TODO ...
+        Ok(())
+    }
+}

src/main.rs

@@ -1,3 +1,30 @@
-fn main() {
+#[macro_use] extern crate rust_util;
-    println!("Hello, world!");
+
-}
+mod cmd;
+mod register;
+mod sign;
+
+use clap::App;
+use cmd::{Command, CommandError};
+use cmd::DefaultCommandImpl;
+
+fn main() -> CommandError {
+    let commands: Vec<Box<dyn Command>> = vec![
+        Box::new(register::CommandImpl),
+        Box::new(sign::CommandImpl),
+    ];
+    let mut app = App::new(env!("CARGO_PKG_NAME"))
+        .version(env!("CARGO_PKG_VERSION"))
+        .about(env!("CARGO_PKG_DESCRIPTION"));
+    app = DefaultCommandImpl::process_command(app);
+    for command in &commands {
+        app = app.subcommand(command.subcommand());
+    }
+    let matches = app.get_matches();
+    for command in &commands {
+        if let Some(sub_cmd_matches) = matches.subcommand_matches(command.name()) {
+            return command.run(&matches, sub_cmd_matches);
+        }
+    }
+    DefaultCommandImpl::run(&matches)
+}

src/register.rs

@@ -0,0 +1,135 @@
+use clap::{ArgMatches, SubCommand, App, Arg};
+use crate::cmd::{Command, CommandError};
+use authenticator::authenticatorservice::AuthenticatorService;
+use authenticator::statecallback::StateCallback;
+use authenticator::{RegisterFlags, StatusUpdate};
+use sha2::{Digest, Sha256};
+use std::sync::mpsc::{channel, RecvError};
+use std::thread;
+use rust_util::XResult;
+use rand::Rng;
+use base64::URL_SAFE_NO_PAD;
+use serde::{Deserialize, Serialize};
+
+#[derive(Clone, Debug, Serialize, Deserialize)]
+struct U2fV2Challenge {
+    challenge: String,
+    version: String,
+    #[serde(rename = "appId")]
+    app_id: String,
+}
+
+impl U2fV2Challenge {
+    fn new_random<S>(app_id: S) -> Self where S: Into<String> {
+        let mut rng = rand::thread_rng();
+        let mut rand_bytes = [0_u8; 32];
+        for i in 0..32 {
+            let b: u8 = rng.gen();
+            rand_bytes[i] = b;
+        }
+
+        let challenge = base64::encode_config(&rand_bytes, URL_SAFE_NO_PAD);
+        Self::new(challenge, app_id)
+    }
+
+    fn new<S1, S2>(challenge: S1, app_id: S2) -> Self where S1: Into<String>, S2: Into<String> {
+        Self {
+            challenge: challenge.into(),
+            version: "U2F_V2".into(),
+            app_id: app_id.into(),
+        }
+    }
+}
+
+pub struct CommandImpl;
+
+impl Command for CommandImpl {
+    fn name(&self) -> &str { "register" }
+
+    fn subcommand<'a>(&self) -> App<'a, 'a> {
+        SubCommand::with_name(self.name()).about("Register subcommand")
+            .arg(Arg::with_name("app-id").long("app-id").default_value("https://example.com").help("App id"))
+    }
+
+    fn run(&self, _arg_matches: &ArgMatches, sub_arg_matches: &ArgMatches) -> CommandError {
+        let mut manager = AuthenticatorService::new()?;
+        manager.add_u2f_usb_hid_platform_transports();
+
+        let app_id = sub_arg_matches.value_of("app-id").unwrap();
+        let timeout_ms = 10000;
+
+        let u2fv2_challenge = U2fV2Challenge::new_random(app_id);
+        let challenge_str = serde_json::to_string(&u2fv2_challenge).unwrap();
+
+        let mut challenge = Sha256::default();
+        Digest::update(&mut challenge, challenge_str.as_bytes());
+        let chall_bytes = challenge.finalize().to_vec();
+
+        let mut application = Sha256::default();
+        // application.update(app_id.as_bytes());
+        Digest::update(&mut application, app_id.as_bytes());
+        let app_bytes = application.finalize().to_vec();
+
+
+        let flags = RegisterFlags::empty();
+
+        let (status_tx, status_rx) = channel::<StatusUpdate>();
+        thread::spawn(move || loop {
+            match status_rx.recv() {
+                Ok(StatusUpdate::DeviceAvailable { dev_info }) => {
+                    debugging!("STATUS: device available: {}", dev_info)
+                }
+                Ok(StatusUpdate::DeviceUnavailable { dev_info }) => {
+                    debugging!("STATUS: device unavailable: {}", dev_info)
+                }
+                Ok(StatusUpdate::Success { dev_info }) => {
+                    debugging!("STATUS: success using device: {}", dev_info);
+                }
+                Err(RecvError) => {
+                    debugging!("STATUS: end");
+                    return;
+                }
+            }
+        });
+
+        let (register_tx, register_rx) = channel();
+        let callback = StateCallback::new(Box::new(move |rv| {
+            register_tx.send(rv).unwrap();
+        }));
+
+        information!("Start U2F register...");
+        information!("App id: {}", app_id);
+        manager.register(
+            flags,
+            timeout_ms,
+            chall_bytes.clone(),
+            app_bytes.clone(),
+            vec![],
+            status_tx.clone(),
+            callback,
+        )?;
+
+        let register_result = register_rx.recv()?;
+        let (register_data, device_info) = register_result?;
+
+        success!("Register result: {}", base64::encode(&register_data));
+        success!("Device info: {}", &device_info);
+        let credential = u2f_get_key_handle_from_register_response(&register_data).unwrap();
+        success!("Key handle: {}", base64::encode(&credential));
+
+        Ok(())
+    }
+}
+
+fn u2f_get_key_handle_from_register_response(register_response: &[u8]) -> XResult<Vec<u8>> {
+    if register_response[0] != 0x05 {
+        return simple_error!("Reserved byte not set correctly");
+    }
+
+    let key_handle_len = register_response[66] as usize;
+    let mut public_key = register_response.to_owned();
+    let mut key_handle = public_key.split_off(67);
+    let _attestation = key_handle.split_off(key_handle_len);
+
+    Ok(key_handle)
+}

src/sign.rs

@@ -0,0 +1,14 @@
+use clap::{ArgMatches, SubCommand, App};
+use crate::cmd::{Command, CommandError};
+
+pub struct CommandImpl;
+
+impl Command for CommandImpl {
+    fn name(&self) -> &str { "sign" }
+    fn subcommand<'a>(&self) -> App<'a, 'a> {
+        SubCommand::with_name(self.name()).about("Sign subcommand")
+    }
+    fn run(&self, _arg_matches: &ArgMatches, _sub_arg_matches: &ArgMatches) -> CommandError {
+        Ok(())
+    }
+}