Add Device::factory_reset method

This patch adds the factory_reset_method to the Device trait that uses
the NK_factory_reset function to perform a factory reset.  The tests
verify that the user and admin PIN are reset and that the OTP storage
and the password safe are deleted.

1 files changed, 33 insertions, 3 deletions

diff --git a/src/device.rs b/src/device.rs
index 4b8cc5c..8702405 100644
--- a/src/device.rs
+++ b/src/device.rs
@@ -510,6 +510,36 @@ pub trait Device: Authenticate + GetPasswordSafe + GenerateOtp {
     fn lock(&self) -> Result<(), CommandError> {
         unsafe { get_command_result(nitrokey_sys::NK_lock_device()) }
     }
+
+    /// Performs a factory reset on the Nitrokey device.
+    ///
+    /// This commands performs a factory reset on the smart card (like the factory reset via `gpg
+    /// --card-edit`) and then clears the flash memory (password safe, one-time passwords etc.).
+    ///
+    /// # Errors
+    ///
+    /// - [`InvalidString`][] if the provided password contains a null byte
+    /// - [`WrongPassword`][] if the admin password is wrong
+    ///
+    /// # Example
+    ///
+    /// ```no_run
+    /// use nitrokey::Device;
+    /// # use nitrokey::CommandError;
+    ///
+    /// # fn try_main() -> Result<(), CommandError> {
+    /// let device = nitrokey::connect()?;
+    /// match device.factory_reset("12345678") {
+    ///     Ok(()) => println!("Performed a factory reset."),
+    ///     Err(err) => println!("Could not perform a factory reset: {}", err),
+    /// };
+    /// #     Ok(())
+    /// # }
+    /// ```
+    fn factory_reset(&self, admin_pin: &str) -> Result<(), CommandError> {
+        let admin_pin_string = get_cstring(admin_pin)?;
+        unsafe { get_command_result(nitrokey_sys::NK_factory_reset(admin_pin_string.as_ptr())) }
+    }
 }
 
 /// Connects to a Nitrokey device.  This method can be used to connect to any connected device,
@@ -700,9 +730,9 @@ impl Storage {
         let new_string = get_cstring(new)?;
         unsafe {
             get_command_result(nitrokey_sys::NK_change_update_password(
-                    current_string.as_ptr(),
-                    new_string.as_ptr(),
-                    ))
+                current_string.as_ptr(),
+                new_string.as_ptr(),
+            ))
         }
     }