Implement Drop for PasswordSafe

By calling NK_lock_device when dropping a PasswordSafe instance, we can
make sure that the password safe cannot be reused without
authentication.

3 files changed, 30 insertions, 2 deletions

diff --git a/TODO.md b/TODO.md
index a2b6395..992b501 100644
--- a/TODO.md
+++ b/TODO.md
@@ -1,6 +1,5 @@
 - Add support for the currently unsupported commands:
   - `NK_set_unencrypted_volume_rorw_pin_type_user`
-  - `NK_lock_device`
   - `NK_factory_reset`
   - `NK_build_aes_key`
   - `NK_is_AES_supported`
@@ -38,3 +37,5 @@
 - Differentiate empty strings and errors (see `result_from_string`).
 - Check integer conversions.
 - Consider implementing `Into<CommandError>` for `(Device, CommandError)`
+- Check error handling in PasswordSafe::drop().
+- Disable creation of multiple password safes at the same time.
diff --git a/src/pws.rs b/src/pws.rs
index 87a71dd..85726c5 100644
--- a/src/pws.rs
+++ b/src/pws.rs
@@ -315,6 +315,14 @@ impl<'a> PasswordSafe<'a> {
     }
 }
 
+impl<'a> Drop for PasswordSafe<'a> {
+    fn drop(&mut self) {
+        unsafe {
+            nitrokey_sys::NK_lock_device();
+        }
+    }
+}
+
 impl GetPasswordSafe for Pro {
     fn get_password_safe(&self, user_pin: &str) -> Result<PasswordSafe, CommandError> {
         get_password_safe(self, user_pin)
diff --git a/src/tests/pws.rs b/src/tests/pws.rs
index 30d6853..d6125a9 100644
--- a/src/tests/pws.rs
+++ b/src/tests/pws.rs
@@ -1,6 +1,7 @@
+use nitrokey_sys;
 use pws::{GetPasswordSafe, PasswordSafe, SLOT_COUNT};
 use tests::util::{Target, ADMIN_PASSWORD, USER_PASSWORD};
-use util::{CommandError, CommandStatus};
+use util::{result_from_string, CommandError, CommandStatus};
 
 fn get_pws(device: &Target) -> PasswordSafe {
     device.get_password_safe(USER_PASSWORD).unwrap()
@@ -22,6 +23,24 @@ fn enable() {
 
 #[test]
 #[cfg_attr(not(any(feature = "test-pro", feature = "test-storage")), ignore)]
+fn drop() {
+    let device = Target::connect().unwrap();
+    {
+        let pws = get_pws(&device);
+        assert_eq!(
+            CommandStatus::Success,
+            pws.write_slot(1, "name", "login", "password")
+        );
+        assert_eq!("name", pws.get_slot_name(1).unwrap());
+        let result = result_from_string(unsafe { nitrokey_sys::NK_get_password_safe_slot_name(1) });
+        assert_eq!(Ok(String::from("name")), result);
+    }
+    let result = result_from_string(unsafe { nitrokey_sys::NK_get_password_safe_slot_name(1) });
+    assert_eq!(Err(CommandError::NotAuthorized), result);
+}
+
+#[test]
+#[cfg_attr(not(any(feature = "test-pro", feature = "test-storage")), ignore)]
 fn get_status() {
     let device = Target::connect().unwrap();
     let pws = get_pws(&device);