Add nitrokey as a dependency to nitrocli

The nitrokey crate provides a simple interface to the Nitrokey Storage
and the Nitrokey Pro based on the libnitrokey library developed by
Nitrokey UG.  The low-level bindings to this library are available in
the nitrokey-sys crate.

This patch adds version v0.2.1 of the nitrokey crate as a dependency
for nitrocli.  It includes the indirect dependencies nitrokey-sys
(version 3.4.1) and rand (version 0.4.3).

Import subrepo nitrokey/:nitrokey at 2eccc96ceec2282b868891befe9cda7f941fbe7b
Import subrepo nitrokey-sys/:nitrokey-sys at f1a11ebf72610fb9cf80ac7f9f147b4ba1a5336f
Import subrepo rand/:rand at d7d5da49daf7ceb3e5940072940d495cced3a1b3

1 files changed, 99 insertions, 0 deletions

diff --git a/nitrokey/src/config.rs b/nitrokey/src/config.rs
new file mode 100644
index 0000000..33bf256
--- /dev/null
+++ b/nitrokey/src/config.rs
@@ -0,0 +1,99 @@
+use util::CommandError;
+
+/// The configuration for a Nitrokey.
+#[derive(Clone, Copy, Debug, PartialEq)]
+pub struct Config {
+    /// If set, the stick will generate a code from the HOTP slot with the given number if numlock
+    /// is pressed.  The slot number must be 0, 1 or 2.
+    pub numlock: Option<u8>,
+    /// If set, the stick will generate a code from the HOTP slot with the given number if capslock
+    /// is pressed.  The slot number must be 0, 1 or 2.
+    pub capslock: Option<u8>,
+    /// If set, the stick will generate a code from the HOTP slot with the given number if
+    /// scrollock is pressed.  The slot number must be 0, 1 or 2.
+    pub scrollock: Option<u8>,
+    /// If set, OTP generation using [`get_hotp_code`][] or [`get_totp_code`][] requires user
+    /// authentication.  Otherwise, OTPs can be generated without authentication.
+    ///
+    /// [`get_hotp_code`]: trait.ProvideOtp.html#method.get_hotp_code
+    /// [`get_totp_code`]: trait.ProvideOtp.html#method.get_totp_code
+    pub user_password: bool,
+}
+
+#[derive(Debug)]
+pub struct RawConfig {
+    pub numlock: u8,
+    pub capslock: u8,
+    pub scrollock: u8,
+    pub user_password: bool,
+}
+
+fn config_otp_slot_to_option(value: u8) -> Option<u8> {
+    if value < 3 {
+        return Some(value);
+    }
+    None
+}
+
+fn option_to_config_otp_slot(value: Option<u8>) -> Result<u8, CommandError> {
+    match value {
+        Some(value) => {
+            if value < 3 {
+                Ok(value)
+            } else {
+                Err(CommandError::InvalidSlot)
+            }
+        }
+        None => Ok(255),
+    }
+}
+
+impl Config {
+    /// Constructs a new instance of this struct.
+    pub fn new(
+        numlock: Option<u8>,
+        capslock: Option<u8>,
+        scrollock: Option<u8>,
+        user_password: bool,
+    ) -> Config {
+        Config {
+            numlock,
+            capslock,
+            scrollock,
+            user_password,
+        }
+    }
+}
+
+impl RawConfig {
+    pub fn try_from(config: Config) -> Result<RawConfig, CommandError> {
+        Ok(RawConfig {
+            numlock: option_to_config_otp_slot(config.numlock)?,
+            capslock: option_to_config_otp_slot(config.capslock)?,
+            scrollock: option_to_config_otp_slot(config.scrollock)?,
+            user_password: config.user_password,
+        })
+    }
+}
+
+impl From<[u8; 5]> for RawConfig {
+    fn from(data: [u8; 5]) -> Self {
+        RawConfig {
+            numlock: data[0],
+            capslock: data[1],
+            scrollock: data[2],
+            user_password: data[3] != 0,
+        }
+    }
+}
+
+impl Into<Config> for RawConfig {
+    fn into(self) -> Config {
+        Config {
+            numlock: config_otp_slot_to_option(self.numlock),
+            capslock: config_otp_slot_to_option(self.capslock),
+            scrollock: config_otp_slot_to_option(self.scrollock),
+            user_password: self.user_password,
+        }
+    }
+}