Update nitrokey crate to 0.4.0-alpha.3

This change updates the version of the nitrokey crate that we use to
0.4.0-alpha.3. This version is the supposedly last pre-release before
0.4.0, with no further major anticipated changes.
In order to integrate with this new version we have to adjust the way we
connect to a Nitrokey device by funneling those connection requests
through a global manager object. The rationale behind that step being
that the underlying libnitrokey actually cannot handle access of
multiple devices at the same time, and so the manager object is used to
prevent accidental wrong concurrent usage.
Because a device object now effectively keeps a reference to the
manager, we need to provide an additional lifetime to that and derived
objects.
Lastly, the use of a manager is also the reason why the tests had to be
adjusted to no longer accept device objects in their signatures, but
only the respective model for which to invoke the test. That is required
because, as elaborated earlier on, having a device object implies having
taken a reference to a manager (in that case owned by nitrokey-test),
and that reference clashes with the nitrocli code itself attempting to
take the manager. We side step this problem by merely accepting a Model
object, which can be passed around independently of the manager itself,
meaning that nitrokey-test does not need to hold such a reference while
the test is run.

Import subrepo nitrokey/:nitrokey at f150d59410eefdec2ae69b2422906a3d1d88aa07
Import subrepo nitrokey-sys/:nitrokey-sys at 8695e2c762807e033a86c8d03974b686d20cdd72
Import subrepo lazy-static/:lazy-static at b4b2b16aaa79dd7548e288455a0dbe4065bf4e1a

1 files changed, 288 insertions, 13 deletions

diff --git a/nitrokey/src/lib.rs b/nitrokey/src/lib.rs
index c35829c..a4402c5 100644
--- a/nitrokey/src/lib.rs
+++ b/nitrokey/src/lib.rs
@@ -9,13 +9,16 @@
 //! performed without authentication, some require user access, and some require admin access.
 //! This is modelled using the types [`User`][] and [`Admin`][].
 //!
-//! Use [`connect`][] to connect to any Nitrokey device.  The method will return a
+//! You can only connect to one Nitrokey at a time.  Use the global [`take`][] function to obtain
+//! an reference to the [`Manager`][] singleton that keeps track of the connections.  Then use the
+//! [`connect`][] method to connect to any Nitrokey device.  The method will return a
 //! [`DeviceWrapper`][] that abstracts over the supported Nitrokey devices.  You can also use
-//! [`Pro::connect`][] or [`Storage::connect`][] to connect to a specific device.
+//! [`connect_model`][], [`connect_pro`][] or [`connect_storage`][] to connect to a specific
+//! device.
 //!
-//! You can then use [`authenticate_user`][] or [`authenticate_admin`][] to get an authenticated
-//! device that can perform operations that require authentication.  You can use [`device`][] to go
-//! back to the unauthenticated device.
+//! You can call [`authenticate_user`][] or [`authenticate_admin`][] to get an authenticated device
+//! that can perform operations that require authentication.  You can use [`device`][] to go back
+//! to the unauthenticated device.
 //!
 //! This makes sure that you can only execute a command if you have the required access rights.
 //! Otherwise, your code will not compile.  The only exception are the methods to generate one-time
@@ -31,7 +34,8 @@
 //! # use nitrokey::Error;
 //!
 //! # fn try_main() -> Result<(), Error> {
-//! let device = nitrokey::connect()?;
+//! let mut manager = nitrokey::take()?;
+//! let device = manager.connect()?;
 //! println!("{}", device.get_serial_number()?);
 //! #     Ok(())
 //! # }
@@ -44,7 +48,8 @@
 //! # use nitrokey::Error;
 //!
 //! # fn try_main() -> Result<(), Error> {
-//! let device = nitrokey::connect()?;
+//! let mut manager = nitrokey::take()?;
+//! let device = manager.connect()?;
 //! let slot_data = OtpSlotData::new(1, "test", "01234567890123456689", OtpMode::SixDigits);
 //! match device.authenticate_admin("12345678") {
 //!     Ok(mut admin) => {
@@ -66,7 +71,8 @@
 //! # use nitrokey::Error;
 //!
 //! # fn try_main() -> Result<(), Error> {
-//! let mut device = nitrokey::connect()?;
+//! let mut manager = nitrokey::take()?;
+//! let mut device = manager.connect()?;
 //! match device.get_hotp_code(1) {
 //!     Ok(code) => println!("Generated HOTP code: {}", code),
 //!     Err(err) => eprintln!("Could not generate HOTP code: {}", err),
@@ -77,9 +83,12 @@
 //!
 //! [`authenticate_admin`]: trait.Authenticate.html#method.authenticate_admin
 //! [`authenticate_user`]: trait.Authenticate.html#method.authenticate_user
-//! [`connect`]: fn.connect.html
-//! [`Pro::connect`]: struct.Pro.html#fn.connect.html
-//! [`Storage::connect`]: struct.Storage.html#fn.connect.html
+//! [`take`]: fn.take.html
+//! [`connect`]: struct.Manager.html#method.connect
+//! [`connect_model`]: struct.Manager.html#method.connect_model
+//! [`connect_pro`]: struct.Manager.html#method.connect_pro
+//! [`connect_storage`]: struct.Manager.html#method.connect_storage
+//! [`manager`]: trait.Device.html#method.manager
 //! [`device`]: struct.User.html#method.device
 //! [`get_hotp_code`]: trait.GenerateOtp.html#method.get_hotp_code
 //! [`get_totp_code`]: trait.GenerateOtp.html#method.get_totp_code
@@ -89,6 +98,9 @@
 
 #![warn(missing_docs, rust_2018_compatibility, rust_2018_idioms, unused)]
 
+#[macro_use(lazy_static)]
+extern crate lazy_static;
+
 mod auth;
 mod config;
 mod device;
@@ -98,14 +110,16 @@ mod pws;
 mod util;
 
 use std::fmt;
+use std::marker;
+use std::sync;
 
 use nitrokey_sys;
 
 pub use crate::auth::{Admin, Authenticate, User};
 pub use crate::config::Config;
 pub use crate::device::{
-    connect, connect_model, Device, DeviceWrapper, Model, Pro, SdCardData, Storage,
-    StorageProductionInfo, StorageStatus, VolumeMode, VolumeStatus,
+    Device, DeviceWrapper, Model, Pro, SdCardData, Storage, StorageProductionInfo, StorageStatus,
+    VolumeMode, VolumeStatus,
 };
 pub use crate::error::{CommandError, CommunicationError, Error, LibraryError};
 pub use crate::otp::{ConfigureOtp, GenerateOtp, OtpMode, OtpSlotData};
@@ -117,6 +131,10 @@ pub const DEFAULT_ADMIN_PIN: &str = "12345678";
 /// The default user PIN for all Nitrokey devices.
 pub const DEFAULT_USER_PIN: &str = "123456";
 
+lazy_static! {
+    static ref MANAGER: sync::Mutex<Manager> = sync::Mutex::new(Manager::new());
+}
+
 /// A version of the libnitrokey library.
 ///
 /// Use the [`get_library_version`](fn.get_library_version.html) function to query the library
@@ -147,6 +165,263 @@ impl fmt::Display for Version {
     }
 }
 
+/// A manager for connections to Nitrokey devices.
+///
+/// Currently, libnitrokey only provides access to one Nitrokey device at the same time.  This
+/// manager struct makes sure that `nitrokey-rs` does not try to connect to two devices at the same
+/// time.
+///
+/// To obtain a reference to an instance of this manager, use the [`take`][] function.  Use one of
+/// the connect methods – [`connect`][], [`connect_model`][], [`connect_pro`][] or
+/// [`connect_storage`][] – to retrieve a [`Device`][] instance.
+///
+/// # Examples
+///
+/// Connect to a single device:
+///
+/// ```no_run
+/// use nitrokey::Device;
+/// # use nitrokey::Error;
+///
+/// # fn try_main() -> Result<(), Error> {
+/// let mut manager = nitrokey::take()?;
+/// let device = manager.connect()?;
+/// println!("{}", device.get_serial_number()?);
+/// #     Ok(())
+/// # }
+/// ```
+///
+/// Connect to a Pro and a Storage device:
+///
+/// ```no_run
+/// use nitrokey::{Device, Model};
+/// # use nitrokey::Error;
+///
+/// # fn try_main() -> Result<(), Error> {
+/// let mut manager = nitrokey::take()?;
+/// let device = manager.connect_model(Model::Pro)?;
+/// println!("Pro: {}", device.get_serial_number()?);
+/// drop(device);
+/// let device = manager.connect_model(Model::Storage)?;
+/// println!("Storage: {}", device.get_serial_number()?);
+/// #     Ok(())
+/// # }
+/// ```
+///
+/// [`connect`]: #method.connect
+/// [`connect_model`]: #method.connect_model
+/// [`connect_pro`]: #method.connect_pro
+/// [`connect_storage`]: #method.connect_storage
+/// [`manager`]: trait.Device.html#method.manager
+/// [`take`]: fn.take.html
+/// [`Device`]: trait.Device.html
+#[derive(Debug)]
+pub struct Manager {
+    marker: marker::PhantomData<()>,
+}
+
+impl Manager {
+    fn new() -> Self {
+        Manager {
+            marker: marker::PhantomData,
+        }
+    }
+
+    /// Connects to a Nitrokey device.
+    ///
+    /// This method can be used to connect to any connected device, both a Nitrokey Pro and a
+    /// Nitrokey Storage.
+    ///
+    /// # Errors
+    ///
+    /// - [`NotConnected`][] if no Nitrokey device is connected
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// use nitrokey::DeviceWrapper;
+    ///
+    /// fn do_something(device: DeviceWrapper) {}
+    ///
+    /// # fn main() -> Result<(), nitrokey::Error> {
+    /// let mut manager = nitrokey::take()?;
+    /// match manager.connect() {
+    ///     Ok(device) => do_something(device),
+    ///     Err(err) => println!("Could not connect to a Nitrokey: {}", err),
+    /// }
+    /// #     Ok(())
+    /// # }
+    /// ```
+    ///
+    /// [`NotConnected`]: enum.CommunicationError.html#variant.NotConnected
+    pub fn connect(&mut self) -> Result<DeviceWrapper<'_>, Error> {
+        if unsafe { nitrokey_sys::NK_login_auto() } == 1 {
+            device::get_connected_device(self)
+        } else {
+            Err(CommunicationError::NotConnected.into())
+        }
+    }
+
+    /// Connects to a Nitrokey device of the given model.
+    ///
+    /// # Errors
+    ///
+    /// - [`NotConnected`][] if no Nitrokey device of the given model is connected
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// use nitrokey::DeviceWrapper;
+    /// use nitrokey::Model;
+    ///
+    /// fn do_something(device: DeviceWrapper) {}
+    ///
+    /// # fn main() -> Result<(), nitrokey::Error> {
+    /// match nitrokey::take()?.connect_model(Model::Pro) {
+    ///     Ok(device) => do_something(device),
+    ///     Err(err) => println!("Could not connect to a Nitrokey Pro: {}", err),
+    /// }
+    /// #     Ok(())
+    /// # }
+    /// ```
+    ///
+    /// [`NotConnected`]: enum.CommunicationError.html#variant.NotConnected
+    pub fn connect_model(&mut self, model: Model) -> Result<DeviceWrapper<'_>, Error> {
+        if device::connect_enum(model) {
+            Ok(device::create_device_wrapper(self, model))
+        } else {
+            Err(CommunicationError::NotConnected.into())
+        }
+    }
+
+    /// Connects to a Nitrokey Pro.
+    ///
+    /// # Errors
+    ///
+    /// - [`NotConnected`][] if no Nitrokey device of the given model is connected
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// use nitrokey::Pro;
+    ///
+    /// fn use_pro(device: Pro) {}
+    ///
+    /// # fn main() -> Result<(), nitrokey::Error> {
+    /// match nitrokey::take()?.connect_pro() {
+    ///     Ok(device) => use_pro(device),
+    ///     Err(err) => println!("Could not connect to the Nitrokey Pro: {}", err),
+    /// }
+    /// #     Ok(())
+    /// # }
+    /// ```
+    ///
+    /// [`NotConnected`]: enum.CommunicationError.html#variant.NotConnected
+    pub fn connect_pro(&mut self) -> Result<Pro<'_>, Error> {
+        if device::connect_enum(device::Model::Pro) {
+            Ok(device::Pro::new(self))
+        } else {
+            Err(CommunicationError::NotConnected.into())
+        }
+    }
+
+    /// Connects to a Nitrokey Storage.
+    ///
+    /// # Errors
+    ///
+    /// - [`NotConnected`][] if no Nitrokey device of the given model is connected
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// use nitrokey::Storage;
+    ///
+    /// fn use_storage(device: Storage) {}
+    ///
+    /// # fn main() -> Result<(), nitrokey::Error> {
+    /// match nitrokey::take()?.connect_storage() {
+    ///     Ok(device) => use_storage(device),
+    ///     Err(err) => println!("Could not connect to the Nitrokey Storage: {}", err),
+    /// }
+    /// #     Ok(())
+    /// # }
+    /// ```
+    ///
+    /// [`NotConnected`]: enum.CommunicationError.html#variant.NotConnected
+    pub fn connect_storage(&mut self) -> Result<Storage<'_>, Error> {
+        if device::connect_enum(Model::Storage) {
+            Ok(Storage::new(self))
+        } else {
+            Err(CommunicationError::NotConnected.into())
+        }
+    }
+}
+
+/// Take an instance of the connection manager, blocking until an instance is available.
+///
+/// There may only be one [`Manager`][] instance at the same time.  If there already is an
+/// instance, this method blocks.  If you want a non-blocking version, use [`take`][].
+///
+/// # Errors
+///
+/// - [`PoisonError`][] if the lock is poisoned
+///
+/// [`take`]: fn.take.html
+/// [`PoisonError`]: struct.Error.html#variant.PoisonError
+/// [`Manager`]: struct.Manager.html
+pub fn take_blocking() -> Result<sync::MutexGuard<'static, Manager>, Error> {
+    MANAGER.lock().map_err(Into::into)
+}
+
+/// Try to take an instance of the connection manager.
+///
+/// There may only be one [`Manager`][] instance at the same time.  If there already is an
+/// instance, a [`ConcurrentAccessError`][] is returned.  If you want a blocking version, use
+/// [`take_blocking`][].  If you want to access the manager instance even if the cache is poisoned,
+/// use [`force_take`][].
+///
+/// # Errors
+///
+/// - [`ConcurrentAccessError`][] if the token for the `Manager` instance cannot be locked
+/// - [`PoisonError`][] if the lock is poisoned
+///
+/// [`take_blocking`]: fn.take_blocking.html
+/// [`force_take`]: fn.force_take.html
+/// [`ConcurrentAccessError`]: struct.Error.html#variant.ConcurrentAccessError
+/// [`PoisonError`]: struct.Error.html#variant.PoisonError
+/// [`Manager`]: struct.Manager.html
+pub fn take() -> Result<sync::MutexGuard<'static, Manager>, Error> {
+    MANAGER.try_lock().map_err(Into::into)
+}
+
+/// Try to take an instance of the connection manager, ignoring a poisoned cache.
+///
+/// There may only be one [`Manager`][] instance at the same time.  If there already is an
+/// instance, a [`ConcurrentAccessError`][] is returned.  If you want a blocking version, use
+/// [`take_blocking`][].
+///
+/// If a thread has previously panicked while accessing the manager instance, the cache is
+/// poisoned.  The default implementation, [`take`][], returns a [`PoisonError`][] on subsequent
+/// calls.  This implementation ignores the poisoned cache and returns the manager instance.
+///
+/// # Errors
+///
+/// - [`ConcurrentAccessError`][] if the token for the `Manager` instance cannot be locked
+///
+/// [`take`]: fn.take.html
+/// [`take_blocking`]: fn.take_blocking.html
+/// [`ConcurrentAccessError`]: struct.Error.html#variant.ConcurrentAccessError
+/// [`Manager`]: struct.Manager.html
+pub fn force_take() -> Result<sync::MutexGuard<'static, Manager>, Error> {
+    match take() {
+        Ok(guard) => Ok(guard),
+        Err(err) => match err {
+            Error::PoisonError(err) => Ok(err.into_inner()),
+            err => Err(err),
+        },
+    }
+}
+
 /// Enables or disables debug output.  Calling this method with `true` is equivalent to setting the
 /// log level to `Debug`; calling it with `false` is equivalent to the log level `Error` (see
 /// [`set_log_level`][]).