Merge branch 'mutable-references' into next

RFC:
	https://lists.sr.ht/~ireas/nitrokey-rs-dev/%3C20190126174327.tbuyk2s535kfiqm4%40localhost%3E
	https://lists.sr.ht/~ireas/nitrokey-rs-dev/%3C43cc304d-23e8-7f95-2167-ce3f0530b81e%40posteo.net%3E

* mutable-references:
  Store mutable reference to Device in PasswordSafe
  Refactor User and Admin to use a mutable reference
  Require mutable reference if method changes device state
  Add device_mut method to DeviceWrapper
  Implement DerefMut for User and Admin

4 files changed, 166 insertions, 148 deletions

diff --git a/tests/device.rs b/tests/device.rs
index 969a7df..bffd767 100644
--- a/tests/device.rs
+++ b/tests/device.rs
@@ -98,42 +98,35 @@ fn get_firmware_version(device: Pro) {
     assert!(version.minor > 0);
 }
 
-fn admin_retry<T: Authenticate + Device>(device: T, suffix: &str, count: u8) -> T {
-    let result = device.authenticate_admin(&(ADMIN_PASSWORD.to_owned() + suffix));
-    let device = match result {
-        Ok(admin) => admin.device(),
-        Err((device, _)) => device,
-    };
+fn admin_retry<T: Authenticate + Device>(device: &mut T, suffix: &str, count: u8) {
+    assert_any_ok!(device.authenticate_admin(&(ADMIN_PASSWORD.to_owned() + suffix)));
     assert_ok!(count, device.get_admin_retry_count());
-    return device;
 }
 
-fn user_retry<T: Authenticate + Device>(device: T, suffix: &str, count: u8) -> T {
-    let result = device.authenticate_user(&(USER_PASSWORD.to_owned() + suffix));
-    let device = match result {
-        Ok(admin) => admin.device(),
-        Err((device, _)) => device,
-    };
+fn user_retry<T: Authenticate + Device>(device: &mut T, suffix: &str, count: u8) {
+    assert_any_ok!(device.authenticate_user(&(USER_PASSWORD.to_owned() + suffix)));
     assert_ok!(count, device.get_user_retry_count());
-    return device;
 }
 
 #[test_device]
 fn get_retry_count(device: DeviceWrapper) {
-    let device = admin_retry(device, "", 3);
-    let device = admin_retry(device, "123", 2);
-    let device = admin_retry(device, "456", 1);
-    let device = admin_retry(device, "", 3);
-
-    let device = user_retry(device, "", 3);
-    let device = user_retry(device, "123", 2);
-    let device = user_retry(device, "456", 1);
-    user_retry(device, "", 3);
+    let mut device = device;
+
+    admin_retry(&mut device, "", 3);
+    admin_retry(&mut device, "123", 2);
+    admin_retry(&mut device, "456", 1);
+    admin_retry(&mut device, "", 3);
+
+    user_retry(&mut device, "", 3);
+    user_retry(&mut device, "123", 2);
+    user_retry(&mut device, "456", 1);
+    user_retry(&mut device, "", 3);
 }
 
 #[test_device]
 fn config(device: DeviceWrapper) {
-    let admin = unwrap_ok!(device.authenticate_admin(ADMIN_PASSWORD));
+    let mut device = device;
+    let mut admin = unwrap_ok!(device.authenticate_admin(ADMIN_PASSWORD));
 
     let config = Config::new(None, None, None, true);
     assert_ok!((), admin.write_config(config));
@@ -153,41 +146,52 @@ fn config(device: DeviceWrapper) {
 
 #[test_device]
 fn change_user_pin(device: DeviceWrapper) {
-    let device = device.authenticate_user(USER_PASSWORD).unwrap().device();
-    let device = device.authenticate_user(USER_NEW_PASSWORD).unwrap_err().0;
+    let mut device = device;
+    assert_any_ok!(device.authenticate_user(USER_PASSWORD));
+    assert_cmd_err!(
+        CommandError::WrongPassword,
+        device.authenticate_user(USER_NEW_PASSWORD)
+    );
 
     assert_ok!((), device.change_user_pin(USER_PASSWORD, USER_NEW_PASSWORD));
 
-    let device = device.authenticate_user(USER_PASSWORD).unwrap_err().0;
-    let device = device
-        .authenticate_user(USER_NEW_PASSWORD)
-        .unwrap()
-        .device();
+    assert_cmd_err!(
+        CommandError::WrongPassword,
+        device.authenticate_user(USER_PASSWORD)
+    );
+    assert_any_ok!(device.authenticate_user(USER_NEW_PASSWORD));
 
     let result = device.change_user_pin(USER_PASSWORD, USER_PASSWORD);
     assert_cmd_err!(CommandError::WrongPassword, result);
 
     assert_ok!((), device.change_user_pin(USER_NEW_PASSWORD, USER_PASSWORD));
 
-    let device = device.authenticate_user(USER_PASSWORD).unwrap().device();
-    assert!(device.authenticate_user(USER_NEW_PASSWORD).is_err());
+    assert_any_ok!(device.authenticate_user(USER_PASSWORD));
+    assert_cmd_err!(
+        CommandError::WrongPassword,
+        device.authenticate_user(USER_NEW_PASSWORD)
+    );
 }
 
 #[test_device]
 fn change_admin_pin(device: DeviceWrapper) {
-    let device = device.authenticate_admin(ADMIN_PASSWORD).unwrap().device();
-    let device = device.authenticate_admin(ADMIN_NEW_PASSWORD).unwrap_err().0;
+    let mut device = device;
+    assert_any_ok!(device.authenticate_admin(ADMIN_PASSWORD));
+    assert_cmd_err!(
+        CommandError::WrongPassword,
+        device.authenticate_admin(ADMIN_NEW_PASSWORD)
+    );
 
     assert_ok!(
         (),
         device.change_admin_pin(ADMIN_PASSWORD, ADMIN_NEW_PASSWORD)
     );
 
-    let device = device.authenticate_admin(ADMIN_PASSWORD).unwrap_err().0;
-    let device = device
-        .authenticate_admin(ADMIN_NEW_PASSWORD)
-        .unwrap()
-        .device();
+    assert_cmd_err!(
+        CommandError::WrongPassword,
+        device.authenticate_admin(ADMIN_PASSWORD)
+    );
+    assert_any_ok!(device.authenticate_admin(ADMIN_NEW_PASSWORD));
 
     assert_cmd_err!(
         CommandError::WrongPassword,
@@ -199,28 +203,24 @@ fn change_admin_pin(device: DeviceWrapper) {
         device.change_admin_pin(ADMIN_NEW_PASSWORD, ADMIN_PASSWORD)
     );
 
-    let device = device.authenticate_admin(ADMIN_PASSWORD).unwrap().device();
-    device.authenticate_admin(ADMIN_NEW_PASSWORD).unwrap_err();
+    assert_any_ok!(device.authenticate_admin(ADMIN_PASSWORD));
+    assert_cmd_err!(
+        CommandError::WrongPassword,
+        device.authenticate_admin(ADMIN_NEW_PASSWORD)
+    );
 }
 
-fn require_failed_user_login<D>(device: D, password: &str, error: CommandError) -> D
-where
-    D: Device + Authenticate,
-    nitrokey::User<D>: std::fmt::Debug,
-{
-    let result = device.authenticate_user(password);
-    assert!(result.is_err());
-    let err = result.unwrap_err();
-    match err.1 {
-        Error::CommandError(err) => assert_eq!(error, err),
-        _ => assert!(false),
-    };
-    err.0
+fn require_failed_user_login<D: Authenticate + Device>(device: &mut D, password: &str) {
+    assert_cmd_err!(
+        CommandError::WrongPassword,
+        device.authenticate_user(password)
+    );
 }
 
 #[test_device]
 fn unlock_user_pin(device: DeviceWrapper) {
-    let device = device.authenticate_user(USER_PASSWORD).unwrap().device();
+    let mut device = device;
+    assert_any_ok!(device.authenticate_user(USER_PASSWORD));
     assert_ok!((), device.unlock_user_pin(ADMIN_PASSWORD, USER_PASSWORD));
     assert_cmd_err!(
         CommandError::WrongPassword,
@@ -229,10 +229,10 @@ fn unlock_user_pin(device: DeviceWrapper) {
 
     // block user PIN
     let wrong_password = USER_PASSWORD.to_owned() + "foo";
-    let device = require_failed_user_login(device, &wrong_password, CommandError::WrongPassword);
-    let device = require_failed_user_login(device, &wrong_password, CommandError::WrongPassword);
-    let device = require_failed_user_login(device, &wrong_password, CommandError::WrongPassword);
-    let device = require_failed_user_login(device, USER_PASSWORD, CommandError::WrongPassword);
+    require_failed_user_login(&mut device, &wrong_password);
+    require_failed_user_login(&mut device, &wrong_password);
+    require_failed_user_login(&mut device, &wrong_password);
+    require_failed_user_login(&mut device, USER_PASSWORD);
 
     // unblock with current PIN
     assert_cmd_err!(
@@ -240,13 +240,13 @@ fn unlock_user_pin(device: DeviceWrapper) {
         device.unlock_user_pin(USER_PASSWORD, USER_PASSWORD)
     );
     assert_ok!((), device.unlock_user_pin(ADMIN_PASSWORD, USER_PASSWORD));
-    let device = device.authenticate_user(USER_PASSWORD).unwrap().device();
+    assert_any_ok!(device.authenticate_user(USER_PASSWORD));
 
     // block user PIN
-    let device = require_failed_user_login(device, &wrong_password, CommandError::WrongPassword);
-    let device = require_failed_user_login(device, &wrong_password, CommandError::WrongPassword);
-    let device = require_failed_user_login(device, &wrong_password, CommandError::WrongPassword);
-    let device = require_failed_user_login(device, USER_PASSWORD, CommandError::WrongPassword);
+    require_failed_user_login(&mut device, &wrong_password);
+    require_failed_user_login(&mut device, &wrong_password);
+    require_failed_user_login(&mut device, &wrong_password);
+    require_failed_user_login(&mut device, USER_PASSWORD);
 
     // unblock with new PIN
     assert_cmd_err!(
@@ -272,12 +272,12 @@ fn assert_utf8_err_or_ne(left: &str, right: Result<String, Error>) {
 
 #[test_device]
 fn factory_reset(device: DeviceWrapper) {
-    let admin = unwrap_ok!(device.authenticate_admin(ADMIN_PASSWORD));
+    let mut device = device;
+    let mut admin = unwrap_ok!(device.authenticate_admin(ADMIN_PASSWORD));
     let otp_data = OtpSlotData::new(1, "test", "0123468790", OtpMode::SixDigits);
     assert_ok!((), admin.write_totp_slot(otp_data, 30));
 
-    let device = admin.device();
-    let pws = unwrap_ok!(device.get_password_safe(USER_PASSWORD));
+    let mut pws = unwrap_ok!(device.get_password_safe(USER_PASSWORD));
     assert_ok!((), pws.write_slot(0, "test", "testlogin", "testpw"));
     drop(pws);
 
@@ -297,23 +297,24 @@ fn factory_reset(device: DeviceWrapper) {
     );
     assert_ok!((), device.factory_reset(ADMIN_NEW_PASSWORD));
 
-    let device = device.authenticate_admin(ADMIN_PASSWORD).unwrap().device();
+    assert_any_ok!(device.authenticate_admin(ADMIN_PASSWORD));
 
     let user = unwrap_ok!(device.authenticate_user(USER_PASSWORD));
     assert_cmd_err!(CommandError::SlotNotProgrammed, user.get_totp_slot_name(1));
 
-    let device = user.device();
     let pws = unwrap_ok!(device.get_password_safe(USER_PASSWORD));
     assert_utf8_err_or_ne("test", pws.get_slot_name(0));
     assert_utf8_err_or_ne("testlogin", pws.get_slot_login(0));
     assert_utf8_err_or_ne("testpw", pws.get_slot_password(0));
+    drop(pws);
 
     assert_ok!((), device.build_aes_key(ADMIN_PASSWORD));
 }
 
 #[test_device]
 fn build_aes_key(device: DeviceWrapper) {
-    let pws = unwrap_ok!(device.get_password_safe(USER_PASSWORD));
+    let mut device = device;
+    let mut pws = unwrap_ok!(device.get_password_safe(USER_PASSWORD));
     assert_ok!((), pws.write_slot(0, "test", "testlogin", "testpw"));
     drop(pws);
 
@@ -323,7 +324,7 @@ fn build_aes_key(device: DeviceWrapper) {
     );
     assert_ok!((), device.build_aes_key(ADMIN_PASSWORD));
 
-    let device = device.authenticate_admin(ADMIN_PASSWORD).unwrap().device();
+    assert_any_ok!(device.authenticate_admin(ADMIN_PASSWORD));
 
     let pws = unwrap_ok!(device.get_password_safe(USER_PASSWORD));
     assert_utf8_err_or_ne("test", pws.get_slot_name(0));
@@ -333,6 +334,7 @@ fn build_aes_key(device: DeviceWrapper) {
 
 #[test_device]
 fn change_update_pin(device: Storage) {
+    let mut device = device;
     assert_cmd_err!(
         CommandError::WrongPassword,
         device.change_update_pin(UPDATE_NEW_PIN, UPDATE_PIN)
@@ -343,6 +345,7 @@ fn change_update_pin(device: Storage) {
 
 #[test_device]
 fn encrypted_volume(device: Storage) {
+    let mut device = device;
     assert_ok!((), device.lock());
 
     assert_eq!(1, count_nitrokey_block_devices());
@@ -361,6 +364,7 @@ fn encrypted_volume(device: Storage) {
 
 #[test_device]
 fn hidden_volume(device: Storage) {
+    let mut device = device;
     assert_ok!((), device.lock());
 
     assert_eq!(1, count_nitrokey_block_devices());
@@ -396,6 +400,7 @@ fn hidden_volume(device: Storage) {
 
 #[test_device]
 fn lock(device: Storage) {
+    let mut device = device;
     assert_ok!((), device.enable_encrypted_volume(USER_PASSWORD));
     assert_ok!((), device.lock());
     assert_eq!(1, count_nitrokey_block_devices());
@@ -405,6 +410,7 @@ fn lock(device: Storage) {
 fn set_encrypted_volume_mode(device: Storage) {
     // This test case does not check the device status as the command only works with firmware
     // version 0.49.  For later versions, it does not do anything and always returns Ok(()).
+    let mut device = device;
 
     assert_ok!(
         (),
@@ -441,12 +447,13 @@ fn set_unencrypted_volume_mode(device: Storage) {
         );
     }
 
-    fn assert_success(device: &Storage, mode: VolumeMode) {
+    fn assert_success(device: &mut Storage, mode: VolumeMode) {
         assert_ok!((), device.set_unencrypted_volume_mode(ADMIN_PASSWORD, mode));
         assert_mode(&device, mode);
     }
 
-    assert_success(&device, VolumeMode::ReadOnly);
+    let mut device = device;
+    assert_success(&mut device, VolumeMode::ReadOnly);
 
     assert_cmd_err!(
         CommandError::WrongPassword,
@@ -454,9 +461,9 @@ fn set_unencrypted_volume_mode(device: Storage) {
     );
     assert_mode(&device, VolumeMode::ReadOnly);
 
-    assert_success(&device, VolumeMode::ReadWrite);
-    assert_success(&device, VolumeMode::ReadWrite);
-    assert_success(&device, VolumeMode::ReadOnly);
+    assert_success(&mut device, VolumeMode::ReadWrite);
+    assert_success(&mut device, VolumeMode::ReadWrite);
+    assert_success(&mut device, VolumeMode::ReadOnly);
 }
 
 #[test_device]
@@ -488,6 +495,7 @@ fn get_production_info(device: Storage) {
 
 #[test_device]
 fn clear_new_sd_card_warning(device: Storage) {
+    let mut device = device;
     assert_ok!((), device.factory_reset(ADMIN_PASSWORD));
     thread::sleep(time::Duration::from_secs(3));
     assert_ok!((), device.build_aes_key(ADMIN_PASSWORD));
@@ -506,6 +514,7 @@ fn clear_new_sd_card_warning(device: Storage) {
 
 #[test_device]
 fn export_firmware(device: Storage) {
+    let mut device = device;
     assert_cmd_err!(
         CommandError::WrongPassword,
         device.export_firmware("someadminpn")
diff --git a/tests/otp.rs b/tests/otp.rs
index fc0e79e..8ca8311 100644
--- a/tests/otp.rs
+++ b/tests/otp.rs
@@ -3,8 +3,7 @@
 
 mod util;
 
-use std::fmt::Debug;
-use std::ops::Deref;
+use std::ops::DerefMut;
 
 use nitrokey::{
     Admin, Authenticate, CommandError, Config, ConfigureOtp, Device, GenerateOtp, LibraryError,
@@ -38,22 +37,19 @@ enum TotpTimestampSize {
     U64,
 }
 
-fn make_admin_test_device<T>(device: T) -> Admin<T>
+fn make_admin_test_device<'a, T>(device: &'a mut T) -> Admin<'a, T>
 where
     T: Device,
-    (T, nitrokey::Error): Debug,
 {
-    device
-        .authenticate_admin(ADMIN_PASSWORD)
-        .expect("Could not login as admin.")
+    unwrap_ok!(device.authenticate_admin(ADMIN_PASSWORD))
 }
 
-fn configure_hotp(admin: &ConfigureOtp, counter: u8) {
+fn configure_hotp(admin: &mut ConfigureOtp, counter: u8) {
     let slot_data = OtpSlotData::new(1, "test-hotp", HOTP_SECRET, OtpMode::SixDigits);
     assert_ok!((), admin.write_hotp_slot(slot_data, counter.into()));
 }
 
-fn check_hotp_codes(device: &GenerateOtp, offset: u8) {
+fn check_hotp_codes(device: &mut GenerateOtp, offset: u8) {
     HOTP_CODES.iter().enumerate().for_each(|(i, code)| {
         if i >= offset as usize {
             assert_ok!(code.to_string(), device.get_hotp_code(1));
@@ -63,6 +59,7 @@ fn check_hotp_codes(device: &GenerateOtp, offset: u8) {
 
 #[test_device]
 fn set_time(device: DeviceWrapper) {
+    let mut device = device;
     assert_ok!((), device.set_time(1546385382, true));
     assert_ok!((), device.set_time(1546385392, false));
     assert_cmd_err!(CommandError::Timestamp, device.set_time(1546385292, false));
@@ -71,47 +68,50 @@ fn set_time(device: DeviceWrapper) {
 
 #[test_device]
 fn hotp_no_pin(device: DeviceWrapper) {
-    let admin = make_admin_test_device(device);
+    let mut device = device;
+    let mut admin = make_admin_test_device(&mut device);
     let config = Config::new(None, None, None, false);
     assert_ok!((), admin.write_config(config));
 
-    configure_hotp(&admin, 0);
-    check_hotp_codes(admin.deref(), 0);
+    configure_hotp(&mut admin, 0);
+    check_hotp_codes(admin.deref_mut(), 0);
 
-    configure_hotp(&admin, 5);
-    check_hotp_codes(admin.deref(), 5);
+    configure_hotp(&mut admin, 5);
+    check_hotp_codes(admin.deref_mut(), 5);
 
-    configure_hotp(&admin, 0);
-    check_hotp_codes(&admin.device(), 0);
+    configure_hotp(&mut admin, 0);
+    check_hotp_codes(&mut device, 0);
 }
 
 #[test_device]
 fn hotp_pin(device: DeviceWrapper) {
-    let admin = make_admin_test_device(device);
+    let mut device = device;
+    let mut admin = make_admin_test_device(&mut device);
     let config = Config::new(None, None, None, true);
     assert_ok!((), admin.write_config(config));
 
-    configure_hotp(&admin, 0);
-    let user = unwrap_ok!(admin.device().authenticate_user(USER_PASSWORD));
-    check_hotp_codes(&user, 0);
+    configure_hotp(&mut admin, 0);
+    let mut user = unwrap_ok!(device.authenticate_user(USER_PASSWORD));
+    check_hotp_codes(&mut user, 0);
 
-    assert_cmd_err!(CommandError::NotAuthorized, user.device().get_hotp_code(1));
+    assert_cmd_err!(CommandError::NotAuthorized, user.get_hotp_code(1));
 }
 
 #[test_device]
 fn hotp_slot_name(device: DeviceWrapper) {
-    let admin = make_admin_test_device(device);
+    let mut device = device;
+    let mut admin = make_admin_test_device(&mut device);
     let slot_data = OtpSlotData::new(1, "test-hotp", HOTP_SECRET, OtpMode::SixDigits);
     assert_ok!((), admin.write_hotp_slot(slot_data, 0));
 
-    let device = admin.device();
     assert_ok!("test-hotp".to_string(), device.get_hotp_slot_name(1));
     assert_lib_err!(LibraryError::InvalidSlot, device.get_hotp_slot_name(4));
 }
 
 #[test_device]
 fn hotp_error(device: DeviceWrapper) {
-    let admin = make_admin_test_device(device);
+    let mut device = device;
+    let mut admin = make_admin_test_device(&mut device);
     let slot_data = OtpSlotData::new(1, "", HOTP_SECRET, OtpMode::SixDigits);
     assert_cmd_err!(CommandError::NoName, admin.write_hotp_slot(slot_data, 0));
     let slot_data = OtpSlotData::new(4, "test", HOTP_SECRET, OtpMode::SixDigits);
@@ -130,7 +130,8 @@ fn hotp_error(device: DeviceWrapper) {
 
 #[test_device]
 fn hotp_erase(device: DeviceWrapper) {
-    let admin = make_admin_test_device(device);
+    let mut device = device;
+    let mut admin = make_admin_test_device(&mut device);
     let config = Config::new(None, None, None, false);
     assert_ok!((), admin.write_config(config));
     let slot_data = OtpSlotData::new(1, "test1", HOTP_SECRET, OtpMode::SixDigits);
@@ -140,7 +141,6 @@ fn hotp_erase(device: DeviceWrapper) {
 
     assert_ok!((), admin.erase_hotp_slot(1));
 
-    let device = admin.device();
     let result = device.get_hotp_slot_name(1);
     assert_cmd_err!(CommandError::SlotNotProgrammed, result);
     let result = device.get_hotp_code(1);
@@ -149,13 +149,13 @@ fn hotp_erase(device: DeviceWrapper) {
     assert_ok!("test2".to_string(), device.get_hotp_slot_name(2));
 }
 
-fn configure_totp(admin: &ConfigureOtp, factor: u64) {
+fn configure_totp(admin: &mut ConfigureOtp, factor: u64) {
     let slot_data = OtpSlotData::new(1, "test-totp", TOTP_SECRET, OtpMode::EightDigits);
     let time_window = 30u64.checked_mul(factor).unwrap();
     assert_ok!((), admin.write_totp_slot(slot_data, time_window as u16));
 }
 
-fn check_totp_codes(device: &GenerateOtp, factor: u64, timestamp_size: TotpTimestampSize) {
+fn check_totp_codes(device: &mut GenerateOtp, factor: u64, timestamp_size: TotpTimestampSize) {
     for (base_time, codes) in TOTP_CODES {
         let time = base_time.checked_mul(factor).unwrap();
         let is_u64 = time > u32::max_value() as u64;
@@ -177,74 +177,76 @@ fn check_totp_codes(device: &GenerateOtp, factor: u64, timestamp_size: TotpTimes
 
 #[test_device]
 fn totp_no_pin(device: DeviceWrapper) {
-    // TODO: this test may fail due to bad timing --> find solution
-    let admin = make_admin_test_device(device);
+    let mut device = device;
+    let mut admin = make_admin_test_device(&mut device);
     let config = Config::new(None, None, None, false);
     assert_ok!((), admin.write_config(config));
 
-    configure_totp(&admin, 1);
-    check_totp_codes(admin.deref(), 1, TotpTimestampSize::U32);
+    configure_totp(&mut admin, 1);
+    check_totp_codes(admin.deref_mut(), 1, TotpTimestampSize::U32);
 
-    configure_totp(&admin, 2);
-    check_totp_codes(admin.deref(), 2, TotpTimestampSize::U32);
+    configure_totp(&mut admin, 2);
+    check_totp_codes(admin.deref_mut(), 2, TotpTimestampSize::U32);
 
-    configure_totp(&admin, 1);
-    check_totp_codes(&admin.device(), 1, TotpTimestampSize::U32);
+    configure_totp(&mut admin, 1);
+    check_totp_codes(&mut device, 1, TotpTimestampSize::U32);
 }
 
 #[test_device]
 // Nitrokey Storage does only support timestamps that fit in a 32-bit
 // unsigned integer, so don't test with it.
 fn totp_no_pin_64(device: Pro) {
-    let admin = make_admin_test_device(device);
+    let mut device = device;
+    let mut admin = make_admin_test_device(&mut device);
     let config = Config::new(None, None, None, false);
     assert_ok!((), admin.write_config(config));
 
-    configure_totp(&admin, 1);
-    check_totp_codes(admin.deref(), 1, TotpTimestampSize::U64);
+    configure_totp(&mut admin, 1);
+    check_totp_codes(admin.deref_mut(), 1, TotpTimestampSize::U64);
 
-    configure_totp(&admin, 2);
-    check_totp_codes(admin.deref(), 2, TotpTimestampSize::U64);
+    configure_totp(&mut admin, 2);
+    check_totp_codes(admin.deref_mut(), 2, TotpTimestampSize::U64);
 
-    configure_totp(&admin, 1);
-    check_totp_codes(&admin.device(), 1, TotpTimestampSize::U64);
+    configure_totp(&mut admin, 1);
+    check_totp_codes(&mut device, 1, TotpTimestampSize::U64);
 }
 
 #[test_device]
 fn totp_pin(device: DeviceWrapper) {
-    // TODO: this test may fail due to bad timing --> find solution
-    let admin = make_admin_test_device(device);
+    let mut device = device;
+    let mut admin = make_admin_test_device(&mut device);
     let config = Config::new(None, None, None, true);
     assert_ok!((), admin.write_config(config));
 
-    configure_totp(&admin, 1);
-    let user = unwrap_ok!(admin.device().authenticate_user(USER_PASSWORD));
-    check_totp_codes(&user, 1, TotpTimestampSize::U32);
+    configure_totp(&mut admin, 1);
+    let mut user = unwrap_ok!(device.authenticate_user(USER_PASSWORD));
+    check_totp_codes(&mut user, 1, TotpTimestampSize::U32);
 
-    assert_cmd_err!(CommandError::NotAuthorized, user.device().get_totp_code(1));
+    assert_cmd_err!(CommandError::NotAuthorized, user.get_totp_code(1));
 }
 
 #[test_device]
 // See comment for totp_no_pin_64.
 fn totp_pin_64(device: Pro) {
-    let admin = make_admin_test_device(device);
+    let mut device = device;
+    let mut admin = make_admin_test_device(&mut device);
     let config = Config::new(None, None, None, true);
     assert_ok!((), admin.write_config(config));
 
-    configure_totp(&admin, 1);
-    let user = unwrap_ok!(admin.device().authenticate_user(USER_PASSWORD));
-    check_totp_codes(&user, 1, TotpTimestampSize::U64);
+    configure_totp(&mut admin, 1);
+    let mut user = unwrap_ok!(admin.authenticate_user(USER_PASSWORD));
+    check_totp_codes(&mut user, 1, TotpTimestampSize::U64);
 
-    assert_cmd_err!(CommandError::NotAuthorized, user.device().get_totp_code(1));
+    assert_cmd_err!(CommandError::NotAuthorized, device.get_totp_code(1));
 }
 
 #[test_device]
 fn totp_slot_name(device: DeviceWrapper) {
-    let admin = make_admin_test_device(device);
+    let mut device = device;
+    let mut admin = make_admin_test_device(&mut device);
     let slot_data = OtpSlotData::new(1, "test-totp", TOTP_SECRET, OtpMode::EightDigits);
     assert_ok!((), admin.write_totp_slot(slot_data, 0));
 
-    let device = admin.device();
     let result = device.get_totp_slot_name(1);
     assert_ok!("test-totp", result);
     let result = device.get_totp_slot_name(16);
@@ -253,7 +255,8 @@ fn totp_slot_name(device: DeviceWrapper) {
 
 #[test_device]
 fn totp_error(device: DeviceWrapper) {
-    let admin = make_admin_test_device(device);
+    let mut device = device;
+    let mut admin = make_admin_test_device(&mut device);
     let slot_data = OtpSlotData::new(1, "", TOTP_SECRET, OtpMode::SixDigits);
     assert_cmd_err!(CommandError::NoName, admin.write_totp_slot(slot_data, 0));
     let slot_data = OtpSlotData::new(20, "test", TOTP_SECRET, OtpMode::SixDigits);
@@ -272,7 +275,8 @@ fn totp_error(device: DeviceWrapper) {
 
 #[test_device]
 fn totp_erase(device: DeviceWrapper) {
-    let admin = make_admin_test_device(device);
+    let mut device = device;
+    let mut admin = make_admin_test_device(&mut device);
     let config = Config::new(None, None, None, false);
     assert_ok!((), admin.write_config(config));
     let slot_data = OtpSlotData::new(1, "test1", TOTP_SECRET, OtpMode::SixDigits);
@@ -282,7 +286,6 @@ fn totp_erase(device: DeviceWrapper) {
 
     assert_ok!((), admin.erase_totp_slot(1));
 
-    let device = admin.device();
     let result = device.get_totp_slot_name(1);
     assert_cmd_err!(CommandError::SlotNotProgrammed, result);
     let result = device.get_totp_code(1);
diff --git a/tests/pws.rs b/tests/pws.rs
index 32dc8f7..7805803 100644
--- a/tests/pws.rs
+++ b/tests/pws.rs
@@ -33,7 +33,7 @@ fn get_slot_name_direct(slot: u8) -> Result<String, Error> {
     }
 }
 
-fn get_pws<T>(device: &T) -> PasswordSafe
+fn get_pws<T>(device: &mut T) -> PasswordSafe
 where
     T: Device,
 {
@@ -42,6 +42,7 @@ where
 
 #[test_device]
 fn enable(device: DeviceWrapper) {
+    let mut device = device;
     assert_cmd_err!(
         CommandError::WrongPassword,
         device.get_password_safe(&(USER_PASSWORD.to_owned() + "123"))
@@ -56,8 +57,9 @@ fn enable(device: DeviceWrapper) {
 
 #[test_device]
 fn drop(device: DeviceWrapper) {
+    let mut device = device;
     {
-        let pws = get_pws(&device);
+        let mut pws = get_pws(&mut device);
         assert_ok!((), pws.write_slot(1, "name", "login", "password"));
         assert_ok!("name".to_string(), pws.get_slot_name(1));
         let result = get_slot_name_direct(1);
@@ -72,7 +74,8 @@ fn drop(device: DeviceWrapper) {
 
 #[test_device]
 fn get_status(device: DeviceWrapper) {
-    let pws = get_pws(&device);
+    let mut device = device;
+    let mut pws = get_pws(&mut device);
     for i in 0..SLOT_COUNT {
         assert_ok!((), pws.erase_slot(i));
     }
@@ -93,7 +96,8 @@ fn get_status(device: DeviceWrapper) {
 
 #[test_device]
 fn get_data(device: DeviceWrapper) {
-    let pws = get_pws(&device);
+    let mut device = device;
+    let mut pws = get_pws(&mut device);
     assert_ok!((), pws.write_slot(1, "name", "login", "password"));
     assert_ok!("name".to_string(), pws.get_slot_name(1));
     assert_ok!("login".to_string(), pws.get_slot_login(1));
@@ -119,7 +123,8 @@ fn get_data(device: DeviceWrapper) {
 
 #[test_device]
 fn write(device: DeviceWrapper) {
-    let pws = get_pws(&device);
+    let mut device = device;
+    let mut pws = get_pws(&mut device);
 
     assert_lib_err!(
         LibraryError::InvalidSlot,
@@ -144,7 +149,8 @@ fn write(device: DeviceWrapper) {
 
 #[test_device]
 fn erase(device: DeviceWrapper) {
-    let pws = get_pws(&device);
+    let mut device = device;
+    let mut pws = get_pws(&mut device);
     assert_lib_err!(LibraryError::InvalidSlot, pws.erase_slot(SLOT_COUNT));
 
     assert_ok!((), pws.write_slot(0, "name", "login", "password"));
diff --git a/tests/util/mod.rs b/tests/util/mod.rs
index bd207a9..f80372d 100644
--- a/tests/util/mod.rs
+++ b/tests/util/mod.rs
@@ -8,7 +8,7 @@ pub static USER_PASSWORD: &str = "123456";
 
 #[macro_export]
 macro_rules! unwrap_ok {
-    ($val:expr) => {{
+    ($val:expr) => {
         match $val {
             Ok(val) => val,
             Err(err) => panic!(
@@ -18,12 +18,12 @@ macro_rules! unwrap_ok {
                 err
             ),
         }
-    }};
+    };
 }
 
 #[macro_export]
 macro_rules! assert_any_ok {
-    ($val:expr) => {{
+    ($val:expr) => {
         match &$val {
             Ok(_) => {}
             Err(err) => panic!(
@@ -33,12 +33,12 @@ macro_rules! assert_any_ok {
                 err
             ),
         }
-    }};
+    };
 }
 
 #[macro_export]
 macro_rules! assert_ok {
-    ($left:expr, $right:expr) => {{
+    ($left:expr, $right:expr) => {
         match &$right {
             Ok(right) => match &$left {
                 left => {
@@ -59,7 +59,7 @@ macro_rules! assert_ok {
                 $left, right_err
             ),
         }
-    }};
+    };
 }
 
 #[macro_export]