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, 171 insertions, 0 deletions

diff --git a/nitrokey/src/util.rs b/nitrokey/src/util.rs
new file mode 100644
index 0000000..6f4fbb0
--- /dev/null
+++ b/nitrokey/src/util.rs
@@ -0,0 +1,171 @@
+use libc::{c_void, free};
+use nitrokey_sys;
+use rand::{OsRng, Rng};
+use std;
+use std::ffi::{CStr, CString};
+use std::fmt;
+use std::os::raw::{c_char, c_int};
+
+/// Error types returned by Nitrokey device or by the library.
+#[derive(Debug, PartialEq)]
+pub enum CommandError {
+    /// A packet with a wrong checksum has been sent or received.
+    WrongCrc,
+    /// A command tried to access an OTP slot that does not exist.
+    WrongSlot,
+    /// A command tried to generate an OTP on a slot that is not configured.
+    SlotNotProgrammed,
+    /// The provided password is wrong.
+    WrongPassword,
+    /// You are not authorized for this command or provided a wrong temporary
+    /// password.
+    NotAuthorized,
+    /// An error occured when getting or setting the time.
+    Timestamp,
+    /// You did not provide a name for the OTP slot.
+    NoName,
+    /// This command is not supported by this device.
+    NotSupported,
+    /// This command is unknown.
+    UnknownCommand,
+    /// AES decryption failed.
+    AesDecryptionFailed,
+    /// An unknown error occured.
+    Unknown,
+    /// You passed a string containing a null byte.
+    InvalidString,
+    /// You passed an invalid slot.
+    InvalidSlot,
+    /// An error occured during random number generation.
+    RngError,
+}
+
+/// Log level for libnitrokey.
+///
+/// Setting the log level to a lower level enables all output from higher levels too.  Currently,
+/// only the log levels `Warning`, `DebugL1`, `Debug` and `DebugL2` are actually used.
+#[derive(Debug, PartialEq)]
+pub enum LogLevel {
+    /// Error messages.  Currently not used.
+    Error,
+    /// Warning messages.
+    Warning,
+    /// Informational messages.  Currently not used.
+    Info,
+    /// Basic debug messages, especially basic information on the sent and received packets.
+    DebugL1,
+    /// Detailed debug messages, especially detailed information on the sent and received packets.
+    Debug,
+    /// Very detailed debug messages, especially detailed information about the control flow for
+    /// device communication (for example function entries and exits).
+    DebugL2,
+}
+
+pub fn owned_str_from_ptr(ptr: *const c_char) -> String {
+    unsafe {
+        return CStr::from_ptr(ptr).to_string_lossy().into_owned();
+    }
+}
+
+pub fn result_from_string(ptr: *const c_char) -> Result<String, CommandError> {
+    if ptr.is_null() {
+        return Err(CommandError::Unknown);
+    }
+    unsafe {
+        let s = owned_str_from_ptr(ptr);
+        free(ptr as *mut c_void);
+        if s.is_empty() {
+            return Err(get_last_error());
+        }
+        return Ok(s);
+    }
+}
+
+pub fn get_command_result(value: c_int) -> Result<(), CommandError> {
+    match value {
+        0 => Ok(()),
+        other => Err(CommandError::from(other)),
+    }
+}
+
+pub fn get_last_result() -> Result<(), CommandError> {
+    let value = unsafe { nitrokey_sys::NK_get_last_command_status() } as c_int;
+    get_command_result(value)
+}
+
+pub fn get_last_error() -> CommandError {
+    return match get_last_result() {
+        Ok(()) => CommandError::Unknown,
+        Err(err) => err,
+    };
+}
+
+pub fn generate_password(length: usize) -> std::io::Result<Vec<u8>> {
+    let mut rng = match OsRng::new() {
+        Ok(rng) => rng,
+        Err(err) => return Err(err),
+    };
+    let mut data = vec![0u8; length];
+    rng.fill_bytes(&mut data[..]);
+    return Ok(data);
+}
+
+pub fn get_cstring<T: Into<Vec<u8>>>(s: T) -> Result<CString, CommandError> {
+    CString::new(s).or(Err(CommandError::InvalidString))
+}
+
+impl fmt::Display for CommandError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        let msg = match *self {
+            CommandError::WrongCrc => "A packet with a wrong checksum has been sent or received",
+            CommandError::WrongSlot => "The given OTP slot does not exist",
+            CommandError::SlotNotProgrammed => "The given OTP slot is not programmed",
+            CommandError::WrongPassword => "The given password is wrong",
+            CommandError::NotAuthorized => {
+                "You are not authorized for this command or provided a wrong temporary password"
+            }
+            CommandError::Timestamp => "An error occured when getting or setting the time",
+            CommandError::NoName => "You did not provide a name for the OTP slot",
+            CommandError::NotSupported => "This command is not supported by this device",
+            CommandError::UnknownCommand => "This command is unknown",
+            CommandError::AesDecryptionFailed => "AES decryption failed",
+            CommandError::Unknown => "An unknown error occured",
+            CommandError::InvalidString => "You passed a string containing a null byte",
+            CommandError::InvalidSlot => "The given slot is invalid",
+            CommandError::RngError => "An error occured during random number generation",
+        };
+        write!(f, "{}", msg)
+    }
+}
+
+impl From<c_int> for CommandError {
+    fn from(value: c_int) -> Self {
+        match value {
+            1 => CommandError::WrongCrc,
+            2 => CommandError::WrongSlot,
+            3 => CommandError::SlotNotProgrammed,
+            4 => CommandError::WrongPassword,
+            5 => CommandError::NotAuthorized,
+            6 => CommandError::Timestamp,
+            7 => CommandError::NoName,
+            8 => CommandError::NotSupported,
+            9 => CommandError::UnknownCommand,
+            10 => CommandError::AesDecryptionFailed,
+            201 => CommandError::InvalidSlot,
+            _ => CommandError::Unknown,
+        }
+    }
+}
+
+impl Into<i32> for LogLevel {
+    fn into(self) -> i32 {
+        match self {
+            LogLevel::Error => 0,
+            LogLevel::Warning => 1,
+            LogLevel::Info => 2,
+            LogLevel::DebugL1 => 3,
+            LogLevel::Debug => 4,
+            LogLevel::DebugL2 => 5,
+        }
+    }
+}