Add the connect_path function to the Manager struct

This patch adds the connect_path function to the Manager struct that
uses NK_connect_with_path to connect to a Nitrokey device at a given USB
path.

1 files changed, 52 insertions, 2 deletions

diff --git a/src/lib.rs b/src/lib.rs
index 5600d24..7e8b3ef 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -16,6 +16,10 @@
 //! [`connect_model`][], [`connect_pro`][] or [`connect_storage`][] to connect to a specific
 //! device.
 //!
+//! To get a list of all connected Nitrokey devices, use the [`list_devices`][] function.  You can
+//! then connect to one of the connected devices using the [`connect_path`][] function of the
+//! `Manager` struct.
+//!
 //! 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.
@@ -86,8 +90,10 @@
 //! [`take`]: fn.take.html
 //! [`connect`]: struct.Manager.html#method.connect
 //! [`connect_model`]: struct.Manager.html#method.connect_model
+//! [`connect_path`]: struct.Manager.html#method.connect_path
 //! [`connect_pro`]: struct.Manager.html#method.connect_pro
 //! [`connect_storage`]: struct.Manager.html#method.connect_storage
+//! [`list_devices`]: fn.list_devices.html
 //! [`manager`]: trait.Device.html#method.manager
 //! [`device`]: struct.User.html#method.device
 //! [`get_hotp_code`]: trait.GenerateOtp.html#method.get_hotp_code
@@ -128,7 +134,7 @@ pub use crate::otp::{ConfigureOtp, GenerateOtp, OtpMode, OtpSlotData};
 pub use crate::pws::{GetPasswordSafe, PasswordSafe, SLOT_COUNT};
 pub use crate::util::LogLevel;
 
-use crate::util::get_last_result;
+use crate::util::{get_cstring, get_last_result};
 
 /// The default admin PIN for all Nitrokey devices.
 pub const DEFAULT_ADMIN_PIN: &str = "12345678";
@@ -296,6 +302,49 @@ impl Manager {
         }
     }
 
+    /// Connects to a Nitrokey device at the given USB path.
+    ///
+    /// To get a list of all connected Nitrokey devices, use the [`list_devices`][] function.  The
+    /// [`DeviceInfo`][] structs returned by that function contain the USB path in the `path`
+    /// field.
+    ///
+    /// # Errors
+    ///
+    /// - [`InvalidString`][] if the USB path contains a null byte
+    /// - [`NotConnected`][] if no Nitrokey device can be found at the given USB path
+    /// - [`UnsupportedModelError`][] if the model of the Nitrokey device at the given USB path is
+    ///   not supported by this crate
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// use nitrokey::DeviceWrapper;
+    ///
+    /// fn use_device(device: DeviceWrapper) {}
+    ///
+    /// let mut manager = nitrokey::take()?;
+    /// let devices = nitrokey::list_devices()?;
+    /// for device in devices {
+    ///     let device = manager.connect_path(device.path)?;
+    ///     use_device(device);
+    /// }
+    /// # Ok::<(), nitrokey::Error>(())
+    /// ```
+    ///
+    /// [`list_devices`]: fn.list_devices.html
+    /// [`DeviceInfo`]: struct.DeviceInfo.html
+    /// [`InvalidString`]: enum.LibraryError.html#variant.InvalidString
+    /// [`NotConnected`]: enum.CommunicationError.html#variant.NotConnected
+    /// [`UnsupportedModelError`]: enum.Error.html#variant.UnsupportedModelError
+    pub fn connect_path<S: Into<Vec<u8>>>(&mut self, path: S) -> Result<DeviceWrapper<'_>, Error> {
+        let path = get_cstring(path)?;
+        if unsafe { nitrokey_sys::NK_connect_with_path(path.as_ptr()) } == 1 {
+            device::get_connected_device(self)
+        } else {
+            Err(CommunicationError::NotConnected.into())
+        }
+    }
+
     /// Connects to a Nitrokey Pro.
     ///
     /// # Errors
@@ -424,7 +473,7 @@ pub fn force_take() -> Result<sync::MutexGuard<'static, Manager>, Error> {
 ///
 /// This functions returns a vector with [`DeviceInfo`][] structs that contain information about
 /// all connected Nitrokey devices.  It will even list unsupported models, although you cannot
-/// connect to them.
+/// connect to them.  To connect to a supported model, call the [`connect_path`][] function.
 ///
 /// # Errors
 ///
@@ -455,6 +504,7 @@ pub fn force_take() -> Result<sync::MutexGuard<'static, Manager>, Error> {
 /// # Ok::<(), nitrokey::Error>(())
 /// ```
 ///
+/// [`connect_path`]: struct.Manager.html#fn.connect_path
 /// [`DeviceInfo`]: struct.DeviceInfo.html
 /// [`NotConnected`]: enum.CommunicationError.html#variant.NotConnected
 /// [`Utf8Error`]: enum.Error.html#variant.Utf8Error