Update nitrokey crate to 0.4.0-alpha.0

This is patch marks the first step in the process of updating the
nitrokey dependency to version 0.4. In particular, it integrates with
the first alpha version.
The main change on the nitrocli side accompanying the version bump is
that the nitrokey::CommandError got replaced by a more general
nitrokey::Error which includes the former variant.

Import subrepo nitrokey/:nitrokey at d433189caefe6bd6c88da7fbb1d6e9304353eb83

5 files changed, 325 insertions, 258 deletions

diff --git a/nitrokey/tests/device.rs b/nitrokey/tests/device.rs
index 849d2ff..c790049 100644
--- a/nitrokey/tests/device.rs
+++ b/nitrokey/tests/device.rs
@@ -1,3 +1,6 @@
+// Copyright (C) 2018-2019 Robin Krahl <robin.krahl@ireas.org>
+// SPDX-License-Identifier: MIT
+
 mod util;
 
 use std::ffi::CStr;
@@ -5,8 +8,8 @@ use std::process::Command;
 use std::{thread, time};
 
 use nitrokey::{
-    Authenticate, CommandError, Config, ConfigureOtp, Device, GenerateOtp, GetPasswordSafe,
-    OtpMode, OtpSlotData, Storage, VolumeMode,
+    Authenticate, CommandError, CommunicationError, Config, ConfigureOtp, Device, Error,
+    GenerateOtp, GetPasswordSafe, LibraryError, OtpMode, OtpSlotData, Storage, VolumeMode,
 };
 use nitrokey_test::test as test_device;
 
@@ -31,11 +34,20 @@ fn count_nitrokey_block_devices() -> usize {
 
 #[test_device]
 fn connect_no_device() {
-    assert!(nitrokey::connect().is_err());
-    assert!(nitrokey::connect_model(nitrokey::Model::Pro).is_err());
-    assert!(nitrokey::connect_model(nitrokey::Model::Storage).is_err());
-    assert!(nitrokey::Pro::connect().is_err());
-    assert!(nitrokey::Storage::connect().is_err());
+    assert_cmu_err!(CommunicationError::NotConnected, nitrokey::connect());
+    assert_cmu_err!(
+        CommunicationError::NotConnected,
+        nitrokey::connect_model(nitrokey::Model::Pro)
+    );
+    assert_cmu_err!(
+        CommunicationError::NotConnected,
+        nitrokey::connect_model(nitrokey::Model::Storage)
+    );
+    assert_cmu_err!(CommunicationError::NotConnected, nitrokey::Pro::connect());
+    assert_cmu_err!(
+        CommunicationError::NotConnected,
+        nitrokey::Storage::connect()
+    );
 }
 
 #[test_device]
@@ -124,23 +136,21 @@ fn get_retry_count(device: DeviceWrapper) {
 #[test_device]
 fn config(device: DeviceWrapper) {
     let admin = device.authenticate_admin(ADMIN_PASSWORD).unwrap();
+
     let config = Config::new(None, None, None, true);
-    assert_eq!(Ok(()), admin.write_config(config));
-    let get_config = admin.get_config().unwrap();
-    assert_eq!(config, get_config);
+    assert_ok!((), admin.write_config(config));
+    assert_ok!(config, admin.get_config());
 
     let config = Config::new(None, Some(9), None, true);
-    assert_eq!(Err(CommandError::InvalidSlot), admin.write_config(config));
+    assert_lib_err!(LibraryError::InvalidSlot, admin.write_config(config));
 
     let config = Config::new(Some(1), None, Some(0), false);
-    assert_eq!(Ok(()), admin.write_config(config));
-    let get_config = admin.get_config().unwrap();
-    assert_eq!(config, get_config);
+    assert_ok!((), admin.write_config(config));
+    assert_ok!(config, admin.get_config());
 
     let config = Config::new(None, None, None, false);
-    assert_eq!(Ok(()), admin.write_config(config));
-    let get_config = admin.get_config().unwrap();
-    assert_eq!(config, get_config);
+    assert_ok!((), admin.write_config(config));
+    assert_ok!(config, admin.get_config());
 }
 
 #[test_device]
@@ -148,9 +158,7 @@ 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;
 
-    assert!(device
-        .change_user_pin(USER_PASSWORD, USER_NEW_PASSWORD)
-        .is_ok());
+    assert_ok!((), device.change_user_pin(USER_PASSWORD, USER_NEW_PASSWORD));
 
     let device = device.authenticate_user(USER_PASSWORD).unwrap_err().0;
     let device = device
@@ -159,11 +167,9 @@ fn change_user_pin(device: DeviceWrapper) {
         .device();
 
     let result = device.change_user_pin(USER_PASSWORD, USER_PASSWORD);
-    assert_eq!(Err(CommandError::WrongPassword), result);
+    assert_cmd_err!(CommandError::WrongPassword, result);
 
-    assert!(device
-        .change_user_pin(USER_NEW_PASSWORD, USER_PASSWORD)
-        .is_ok());
+    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());
@@ -174,9 +180,10 @@ 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;
 
-    assert!(device
-        .change_admin_pin(ADMIN_PASSWORD, ADMIN_NEW_PASSWORD)
-        .is_ok());
+    assert_ok!(
+        (),
+        device.change_admin_pin(ADMIN_PASSWORD, ADMIN_NEW_PASSWORD)
+    );
 
     let device = device.authenticate_admin(ADMIN_PASSWORD).unwrap_err().0;
     let device = device
@@ -184,14 +191,15 @@ fn change_admin_pin(device: DeviceWrapper) {
         .unwrap()
         .device();
 
-    assert_eq!(
-        Err(CommandError::WrongPassword),
+    assert_cmd_err!(
+        CommandError::WrongPassword,
         device.change_admin_pin(ADMIN_PASSWORD, ADMIN_PASSWORD)
     );
 
-    assert!(device
-        .change_admin_pin(ADMIN_NEW_PASSWORD, ADMIN_PASSWORD)
-        .is_ok());
+    assert_ok!(
+        (),
+        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();
@@ -205,18 +213,19 @@ where
     let result = device.authenticate_user(password);
     assert!(result.is_err());
     let err = result.unwrap_err();
-    assert_eq!(error, err.1);
+    match err.1 {
+        Error::CommandError(err) => assert_eq!(error, err),
+        _ => assert!(false),
+    };
     err.0
 }
 
 #[test_device]
 fn unlock_user_pin(device: DeviceWrapper) {
     let device = device.authenticate_user(USER_PASSWORD).unwrap().device();
-    assert!(device
-        .unlock_user_pin(ADMIN_PASSWORD, USER_PASSWORD)
-        .is_ok());
-    assert_eq!(
-        Err(CommandError::WrongPassword),
+    assert_ok!((), device.unlock_user_pin(ADMIN_PASSWORD, USER_PASSWORD));
+    assert_cmd_err!(
+        CommandError::WrongPassword,
         device.unlock_user_pin(USER_PASSWORD, USER_PASSWORD)
     );
 
@@ -228,13 +237,11 @@ fn unlock_user_pin(device: DeviceWrapper) {
     let device = require_failed_user_login(device, USER_PASSWORD, CommandError::WrongPassword);
 
     // unblock with current PIN
-    assert_eq!(
-        Err(CommandError::WrongPassword),
+    assert_cmd_err!(
+        CommandError::WrongPassword,
         device.unlock_user_pin(USER_PASSWORD, USER_PASSWORD)
     );
-    assert!(device
-        .unlock_user_pin(ADMIN_PASSWORD, USER_PASSWORD)
-        .is_ok());
+    assert_ok!((), device.unlock_user_pin(ADMIN_PASSWORD, USER_PASSWORD));
     let device = device.authenticate_user(USER_PASSWORD).unwrap().device();
 
     // block user PIN
@@ -244,57 +251,50 @@ fn unlock_user_pin(device: DeviceWrapper) {
     let device = require_failed_user_login(device, USER_PASSWORD, CommandError::WrongPassword);
 
     // unblock with new PIN
-    assert_eq!(
-        Err(CommandError::WrongPassword),
+    assert_cmd_err!(
+        CommandError::WrongPassword,
         device.unlock_user_pin(USER_PASSWORD, USER_PASSWORD)
     );
-    assert!(device
-        .unlock_user_pin(ADMIN_PASSWORD, USER_NEW_PASSWORD)
-        .is_ok());
+    assert_ok!(
+        (),
+        device.unlock_user_pin(ADMIN_PASSWORD, USER_NEW_PASSWORD)
+    );
 
     // reset user PIN
-    assert!(device
-        .change_user_pin(USER_NEW_PASSWORD, USER_PASSWORD)
-        .is_ok());
+    assert_ok!((), device.change_user_pin(USER_NEW_PASSWORD, USER_PASSWORD));
 }
 
 #[test_device]
 fn factory_reset(device: DeviceWrapper) {
     let admin = device.authenticate_admin(ADMIN_PASSWORD).unwrap();
     let otp_data = OtpSlotData::new(1, "test", "0123468790", OtpMode::SixDigits);
-    assert_eq!(Ok(()), admin.write_totp_slot(otp_data, 30));
+    assert_ok!((), admin.write_totp_slot(otp_data, 30));
 
     let device = admin.device();
     let pws = device.get_password_safe(USER_PASSWORD).unwrap();
-    assert_eq!(Ok(()), pws.write_slot(0, "test", "testlogin", "testpw"));
+    assert_ok!((), pws.write_slot(0, "test", "testlogin", "testpw"));
     drop(pws);
 
-    assert_eq!(
-        Ok(()),
-        device.change_user_pin(USER_PASSWORD, USER_NEW_PASSWORD)
-    );
-    assert_eq!(
-        Ok(()),
+    assert_ok!((), device.change_user_pin(USER_PASSWORD, USER_NEW_PASSWORD));
+    assert_ok!(
+        (),
         device.change_admin_pin(ADMIN_PASSWORD, ADMIN_NEW_PASSWORD)
     );
 
-    assert_eq!(
-        Err(CommandError::WrongPassword),
+    assert_cmd_err!(
+        CommandError::WrongPassword,
         device.factory_reset(USER_NEW_PASSWORD)
     );
-    assert_eq!(
-        Err(CommandError::WrongPassword),
+    assert_cmd_err!(
+        CommandError::WrongPassword,
         device.factory_reset(ADMIN_PASSWORD)
     );
-    assert_eq!(Ok(()), device.factory_reset(ADMIN_NEW_PASSWORD));
+    assert_ok!((), device.factory_reset(ADMIN_NEW_PASSWORD));
 
     let device = device.authenticate_admin(ADMIN_PASSWORD).unwrap().device();
 
     let user = device.authenticate_user(USER_PASSWORD).unwrap();
-    assert_eq!(
-        Err(CommandError::SlotNotProgrammed),
-        user.get_totp_slot_name(1)
-    );
+    assert_cmd_err!(CommandError::SlotNotProgrammed, user.get_totp_slot_name(1));
 
     let device = user.device();
     let pws = device.get_password_safe(USER_PASSWORD).unwrap();
@@ -302,20 +302,20 @@ fn factory_reset(device: DeviceWrapper) {
     assert_ne!("testlogin".to_string(), pws.get_slot_login(0).unwrap());
     assert_ne!("testpw".to_string(), pws.get_slot_password(0).unwrap());
 
-    assert_eq!(Ok(()), device.build_aes_key(ADMIN_PASSWORD));
+    assert_ok!((), device.build_aes_key(ADMIN_PASSWORD));
 }
 
 #[test_device]
 fn build_aes_key(device: DeviceWrapper) {
     let pws = device.get_password_safe(USER_PASSWORD).unwrap();
-    assert_eq!(Ok(()), pws.write_slot(0, "test", "testlogin", "testpw"));
+    assert_ok!((), pws.write_slot(0, "test", "testlogin", "testpw"));
     drop(pws);
 
-    assert_eq!(
-        Err(CommandError::WrongPassword),
+    assert_cmd_err!(
+        CommandError::WrongPassword,
         device.build_aes_key(USER_PASSWORD)
     );
-    assert_eq!(Ok(()), device.build_aes_key(ADMIN_PASSWORD));
+    assert_ok!((), device.build_aes_key(ADMIN_PASSWORD));
 
     let device = device.authenticate_admin(ADMIN_PASSWORD).unwrap().device();
 
@@ -327,74 +327,71 @@ fn build_aes_key(device: DeviceWrapper) {
 
 #[test_device]
 fn change_update_pin(device: Storage) {
-    assert_eq!(
-        Err(CommandError::WrongPassword),
+    assert_cmd_err!(
+        CommandError::WrongPassword,
         device.change_update_pin(UPDATE_NEW_PIN, UPDATE_PIN)
     );
-    assert_eq!(Ok(()), device.change_update_pin(UPDATE_PIN, UPDATE_NEW_PIN));
-    assert_eq!(Ok(()), device.change_update_pin(UPDATE_NEW_PIN, UPDATE_PIN));
+    assert_ok!((), device.change_update_pin(UPDATE_PIN, UPDATE_NEW_PIN));
+    assert_ok!((), device.change_update_pin(UPDATE_NEW_PIN, UPDATE_PIN));
 }
 
 #[test_device]
 fn encrypted_volume(device: Storage) {
-    assert_eq!(Ok(()), device.lock());
+    assert_ok!((), device.lock());
 
     assert_eq!(1, count_nitrokey_block_devices());
-    assert_eq!(Ok(()), device.disable_encrypted_volume());
+    assert_ok!((), device.disable_encrypted_volume());
     assert_eq!(1, count_nitrokey_block_devices());
-    assert_eq!(
-        Err(CommandError::WrongPassword),
+    assert_cmd_err!(
+        CommandError::WrongPassword,
         device.enable_encrypted_volume("123")
     );
     assert_eq!(1, count_nitrokey_block_devices());
-    assert_eq!(Ok(()), device.enable_encrypted_volume(USER_PASSWORD));
+    assert_ok!((), device.enable_encrypted_volume(USER_PASSWORD));
     assert_eq!(2, count_nitrokey_block_devices());
-    assert_eq!(Ok(()), device.disable_encrypted_volume());
+    assert_ok!((), device.disable_encrypted_volume());
     assert_eq!(1, count_nitrokey_block_devices());
 }
 
 #[test_device]
 fn hidden_volume(device: Storage) {
-    assert_eq!(Ok(()), device.lock());
+    assert_ok!((), device.lock());
 
     assert_eq!(1, count_nitrokey_block_devices());
-    assert_eq!(Ok(()), device.disable_hidden_volume());
+    assert_ok!((), device.disable_hidden_volume());
     assert_eq!(1, count_nitrokey_block_devices());
 
-    assert_eq!(Ok(()), device.enable_encrypted_volume(USER_PASSWORD));
+    assert_ok!((), device.enable_encrypted_volume(USER_PASSWORD));
     assert_eq!(2, count_nitrokey_block_devices());
 
     // TODO: why this error code?
-    assert_eq!(
-        Err(CommandError::WrongPassword),
+    assert_cmd_err!(
+        CommandError::WrongPassword,
         device.create_hidden_volume(5, 0, 100, "hiddenpw")
     );
-    assert_eq!(Ok(()), device.create_hidden_volume(0, 20, 21, "hidden-pw"));
-    assert_eq!(
-        Ok(()),
-        device.create_hidden_volume(0, 20, 21, "hiddenpassword")
-    );
-    assert_eq!(Ok(()), device.create_hidden_volume(1, 0, 1, "otherpw"));
+    assert_ok!((), device.create_hidden_volume(0, 20, 21, "hidden-pw"));
+    assert_ok!((), device.create_hidden_volume(0, 20, 21, "hiddenpassword"));
+    assert_ok!((), device.create_hidden_volume(1, 0, 1, "otherpw"));
     // TODO: test invalid range (not handled by libnitrokey)
     assert_eq!(2, count_nitrokey_block_devices());
 
-    assert_eq!(
-        Err(CommandError::WrongPassword),
+    assert_cmd_err!(
+        CommandError::WrongPassword,
         device.enable_hidden_volume("blubb")
     );
-    assert_eq!(Ok(()), device.enable_hidden_volume("hiddenpassword"));
+    assert_ok!((), device.enable_hidden_volume("hiddenpassword"));
     assert_eq!(2, count_nitrokey_block_devices());
-    assert_eq!(Ok(()), device.enable_hidden_volume("otherpw"));
+    assert_ok!((), device.enable_hidden_volume("otherpw"));
     assert_eq!(2, count_nitrokey_block_devices());
 
-    assert_eq!(Ok(()), device.disable_hidden_volume());
+    assert_ok!((), device.disable_hidden_volume());
     assert_eq!(1, count_nitrokey_block_devices());
 }
 
 #[test_device]
 fn lock(device: Storage) {
-    assert_eq!(Ok(()), device.enable_encrypted_volume(USER_PASSWORD));
-    assert_eq!(Ok(()), device.lock());
+    assert_ok!((), device.enable_encrypted_volume(USER_PASSWORD));
+    assert_ok!((), device.lock());
     assert_eq!(1, count_nitrokey_block_devices());
 }
 
@@ -410,17 +407,14 @@ fn set_unencrypted_volume_mode(device: Storage) {
     }
 
     fn assert_success(device: &Storage, mode: VolumeMode) {
-        assert_eq!(
-            Ok(()),
-            device.set_unencrypted_volume_mode(ADMIN_PASSWORD, mode)
-        );
+        assert_ok!((), device.set_unencrypted_volume_mode(ADMIN_PASSWORD, mode));
         assert_mode(&device, mode);
     }
 
     assert_success(&device, VolumeMode::ReadOnly);
 
-    assert_eq!(
-        Err(CommandError::WrongPassword),
+    assert_cmd_err!(
+        CommandError::WrongPassword,
         device.set_unencrypted_volume_mode(USER_PASSWORD, VolumeMode::ReadOnly)
     );
     assert_mode(&device, VolumeMode::ReadOnly);
@@ -441,8 +435,8 @@ fn get_storage_status(device: Storage) {
 #[test_device]
 fn get_production_info(device: Storage) {
     let info = device.get_production_info().unwrap();
-    assert_eq!(0, info.firmware_version_major);
-    assert!(info.firmware_version_minor != 0);
+    assert_eq!(0, info.firmware_version.major);
+    assert!(info.firmware_version.minor != 0);
     assert!(info.serial_number_cpu != 0);
     assert!(info.sd_card.serial_number != 0);
     assert!(info.sd_card.size > 0);
@@ -454,24 +448,23 @@ fn get_production_info(device: Storage) {
     assert!(info.sd_card.manufacturer != 0);
 
     let status = device.get_status().unwrap();
-    assert_eq!(status.firmware_version_major, info.firmware_version_major);
-    assert_eq!(status.firmware_version_minor, info.firmware_version_minor);
+    assert_eq!(status.firmware_version, info.firmware_version);
     assert_eq!(status.serial_number_sd_card, info.sd_card.serial_number);
 }
 
 #[test_device]
 fn clear_new_sd_card_warning(device: Storage) {
-    assert_eq!(Ok(()), device.factory_reset(ADMIN_PASSWORD));
+    assert_ok!((), device.factory_reset(ADMIN_PASSWORD));
     thread::sleep(time::Duration::from_secs(3));
-    assert_eq!(Ok(()), device.build_aes_key(ADMIN_PASSWORD));
+    assert_ok!((), device.build_aes_key(ADMIN_PASSWORD));
 
     // We have to perform an SD card operation to reset the new_sd_card_found field
-    assert_eq!(Ok(()), device.lock());
+    assert_ok!((), device.lock());
 
     let status = device.get_status().unwrap();
     assert!(status.new_sd_card_found);
 
-    assert_eq!(Ok(()), device.clear_new_sd_card_warning(ADMIN_PASSWORD));
+    assert_ok!((), device.clear_new_sd_card_warning(ADMIN_PASSWORD));
 
     let status = device.get_status().unwrap();
     assert!(!status.new_sd_card_found);
@@ -479,18 +472,18 @@ fn clear_new_sd_card_warning(device: Storage) {
 
 #[test_device]
 fn export_firmware(device: Storage) {
-    assert_eq!(
-        Err(CommandError::WrongPassword),
+    assert_cmd_err!(
+        CommandError::WrongPassword,
         device.export_firmware("someadminpn")
     );
-    assert_eq!(Ok(()), device.export_firmware(ADMIN_PASSWORD));
-    assert_eq!(
-        Ok(()),
+    assert_ok!((), device.export_firmware(ADMIN_PASSWORD));
+    assert_ok!(
+        (),
         device.set_unencrypted_volume_mode(ADMIN_PASSWORD, VolumeMode::ReadWrite)
     );
-    assert_eq!(Ok(()), device.export_firmware(ADMIN_PASSWORD));
-    assert_eq!(
-        Ok(()),
+    assert_ok!((), device.export_firmware(ADMIN_PASSWORD));
+    assert_ok!(
+        (),
         device.set_unencrypted_volume_mode(ADMIN_PASSWORD, VolumeMode::ReadOnly)
     );
 }
diff --git a/nitrokey/tests/lib.rs b/nitrokey/tests/lib.rs
index c92e224..697024d 100644
--- a/nitrokey/tests/lib.rs
+++ b/nitrokey/tests/lib.rs
@@ -1,6 +1,9 @@
+// Copyright (C) 2019 Robin Krahl <robin.krahl@ireas.org>
+// SPDX-License-Identifier: MIT
+
 #[test]
 fn get_library_version() {
-    let version = nitrokey::get_library_version();
+    let version = nitrokey::get_library_version().unwrap();
 
     assert!(version.git.is_empty() || version.git.starts_with("v"));
     assert!(version.major > 0);
diff --git a/nitrokey/tests/otp.rs b/nitrokey/tests/otp.rs
index 712f7a2..e424673 100644
--- a/nitrokey/tests/otp.rs
+++ b/nitrokey/tests/otp.rs
@@ -1,11 +1,14 @@
+// Copyright (C) 2018-2019 Robin Krahl <robin.krahl@ireas.org>
+// SPDX-License-Identifier: MIT
+
 mod util;
 
 use std::fmt::Debug;
 use std::ops::Deref;
 
 use nitrokey::{
-    Admin, Authenticate, CommandError, Config, ConfigureOtp, Device, GenerateOtp, OtpMode,
-    OtpSlotData,
+    Admin, Authenticate, CommandError, Config, ConfigureOtp, Device, GenerateOtp, LibraryError,
+    OtpMode, OtpSlotData,
 };
 use nitrokey_test::test as test_device;
 
@@ -20,13 +23,13 @@ static HOTP_CODES: &[&str] = &[
 
 // test suite according to RFC 6238, Appendix B
 static TOTP_SECRET: &str = "3132333435363738393031323334353637383930";
-static TOTP_CODES: &[(u64, &str)] = &[
-    (59, "94287082"),
-    (1111111109, "07081804"),
-    (1111111111, "14050471"),
-    (1234567890, "89005924"),
-    (2000000000, "69279037"),
-    (20000000000, "65353130"),
+static TOTP_CODES: &[(u64, &[&str])] = &[
+    (59, &["94287082", "37359152"]),
+    (1111111109, &["07081804"]),
+    (1111111111, &["14050471"]),
+    (1234567890, &["89005924"]),
+    (2000000000, &["69279037"]),
+    (20000000000, &["65353130"]),
 ];
 
 #[derive(PartialEq)]
@@ -38,7 +41,7 @@ enum TotpTimestampSize {
 fn make_admin_test_device<T>(device: T) -> Admin<T>
 where
     T: Device,
-    (T, nitrokey::CommandError): Debug,
+    (T, nitrokey::Error): Debug,
 {
     device
         .authenticate_admin(ADMIN_PASSWORD)
@@ -47,7 +50,7 @@ where
 
 fn configure_hotp(admin: &ConfigureOtp, counter: u8) {
     let slot_data = OtpSlotData::new(1, "test-hotp", HOTP_SECRET, OtpMode::SixDigits);
-    assert_eq!(Ok(()), admin.write_hotp_slot(slot_data, counter.into()));
+    assert_ok!((), admin.write_hotp_slot(slot_data, counter.into()));
 }
 
 fn check_hotp_codes(device: &GenerateOtp, offset: u8) {
@@ -61,20 +64,17 @@ fn check_hotp_codes(device: &GenerateOtp, offset: u8) {
 
 #[test_device]
 fn set_time(device: DeviceWrapper) {
-    assert_eq!(Ok(()), device.set_time(1546385382, true));
-    assert_eq!(Ok(()), device.set_time(1546385392, false));
-    assert_eq!(
-        Err(CommandError::Timestamp),
-        device.set_time(1546385292, false)
-    );
-    assert_eq!(Ok(()), device.set_time(1546385382, true));
+    assert_ok!((), device.set_time(1546385382, true));
+    assert_ok!((), device.set_time(1546385392, false));
+    assert_cmd_err!(CommandError::Timestamp, device.set_time(1546385292, false));
+    assert_ok!((), device.set_time(1546385382, true));
 }
 
 #[test_device]
 fn hotp_no_pin(device: DeviceWrapper) {
     let admin = make_admin_test_device(device);
     let config = Config::new(None, None, None, false);
-    assert_eq!(Ok(()), admin.write_config(config));
+    assert_ok!((), admin.write_config(config));
 
     configure_hotp(&admin, 0);
     check_hotp_codes(admin.deref(), 0);
@@ -90,67 +90,64 @@ fn hotp_no_pin(device: DeviceWrapper) {
 fn hotp_pin(device: DeviceWrapper) {
     let admin = make_admin_test_device(device);
     let config = Config::new(None, None, None, true);
-    assert_eq!(Ok(()), admin.write_config(config));
+    assert_ok!((), admin.write_config(config));
 
     configure_hotp(&admin, 0);
     let user = admin.device().authenticate_user(USER_PASSWORD).unwrap();
     check_hotp_codes(&user, 0);
 
-    assert!(user.device().get_hotp_code(1).is_err());
+    assert_cmd_err!(CommandError::NotAuthorized, user.device().get_hotp_code(1));
 }
 
 #[test_device]
 fn hotp_slot_name(device: DeviceWrapper) {
     let admin = make_admin_test_device(device);
     let slot_data = OtpSlotData::new(1, "test-hotp", HOTP_SECRET, OtpMode::SixDigits);
-    assert_eq!(Ok(()), admin.write_hotp_slot(slot_data, 0));
+    assert_ok!((), admin.write_hotp_slot(slot_data, 0));
 
     let device = admin.device();
     let result = device.get_hotp_slot_name(1);
     assert_eq!("test-hotp", result.unwrap());
     let result = device.get_hotp_slot_name(4);
-    assert_eq!(CommandError::InvalidSlot, result.unwrap_err());
+    assert_lib_err!(LibraryError::InvalidSlot, result);
 }
 
 #[test_device]
 fn hotp_error(device: DeviceWrapper) {
     let admin = make_admin_test_device(device);
     let slot_data = OtpSlotData::new(1, "", HOTP_SECRET, OtpMode::SixDigits);
-    assert_eq!(
-        Err(CommandError::NoName),
-        admin.write_hotp_slot(slot_data, 0)
-    );
+    assert_cmd_err!(CommandError::NoName, admin.write_hotp_slot(slot_data, 0));
     let slot_data = OtpSlotData::new(4, "test", HOTP_SECRET, OtpMode::SixDigits);
-    assert_eq!(
-        Err(CommandError::InvalidSlot),
+    assert_lib_err!(
+        LibraryError::InvalidSlot,
         admin.write_hotp_slot(slot_data, 0)
     );
     let slot_data = OtpSlotData::new(1, "test", "foobar", OtpMode::SixDigits);
-    assert_eq!(
-        Err(CommandError::InvalidHexString),
+    assert_lib_err!(
+        LibraryError::InvalidHexString,
         admin.write_hotp_slot(slot_data, 0)
     );
     let code = admin.get_hotp_code(4);
-    assert_eq!(CommandError::InvalidSlot, code.unwrap_err());
+    assert_lib_err!(LibraryError::InvalidSlot, code);
 }
 
 #[test_device]
 fn hotp_erase(device: DeviceWrapper) {
     let admin = make_admin_test_device(device);
     let config = Config::new(None, None, None, false);
-    assert_eq!(Ok(()), admin.write_config(config));
+    assert_ok!((), admin.write_config(config));
     let slot_data = OtpSlotData::new(1, "test1", HOTP_SECRET, OtpMode::SixDigits);
-    assert_eq!(Ok(()), admin.write_hotp_slot(slot_data, 0));
+    assert_ok!((), admin.write_hotp_slot(slot_data, 0));
     let slot_data = OtpSlotData::new(2, "test2", HOTP_SECRET, OtpMode::SixDigits);
-    assert_eq!(Ok(()), admin.write_hotp_slot(slot_data, 0));
+    assert_ok!((), admin.write_hotp_slot(slot_data, 0));
 
-    assert_eq!(Ok(()), admin.erase_hotp_slot(1));
+    assert_ok!((), admin.erase_hotp_slot(1));
 
     let device = admin.device();
     let result = device.get_hotp_slot_name(1);
-    assert_eq!(CommandError::SlotNotProgrammed, result.unwrap_err());
+    assert_cmd_err!(CommandError::SlotNotProgrammed, result);
     let result = device.get_hotp_code(1);
-    assert_eq!(CommandError::SlotNotProgrammed, result.unwrap_err());
+    assert_cmd_err!(CommandError::SlotNotProgrammed, result);
 
     assert_eq!("test2", device.get_hotp_slot_name(2).unwrap());
 }
@@ -158,25 +155,25 @@ fn hotp_erase(device: DeviceWrapper) {
 fn configure_totp(admin: &ConfigureOtp, factor: u64) {
     let slot_data = OtpSlotData::new(1, "test-totp", TOTP_SECRET, OtpMode::EightDigits);
     let time_window = 30u64.checked_mul(factor).unwrap();
-    assert_eq!(Ok(()), admin.write_totp_slot(slot_data, time_window as u16));
+    assert_ok!((), admin.write_totp_slot(slot_data, time_window as u16));
 }
 
 fn check_totp_codes(device: &GenerateOtp, factor: u64, timestamp_size: TotpTimestampSize) {
-    for (i, &(base_time, code)) in TOTP_CODES.iter().enumerate() {
+    for (base_time, codes) in TOTP_CODES {
         let time = base_time.checked_mul(factor).unwrap();
         let is_u64 = time > u32::max_value() as u64;
         if is_u64 != (timestamp_size == TotpTimestampSize::U64) {
             continue;
         }
 
-        assert_eq!(Ok(()), device.set_time(time, true));
-        let result = device.get_totp_code(1);
-        assert!(result.is_ok());
-        let result_code = result.unwrap();
-        assert_eq!(
-            code, result_code,
-            "TOTP code {} should be {} but is {}",
-            i, code, result_code
+        assert_ok!((), device.set_time(time, true));
+        let code = device.get_totp_code(1).unwrap();
+        assert!(
+            code.contains(&code),
+            "Generated TOTP code {} for {}, but expected one of {}",
+            code,
+            base_time,
+            codes.join(", ")
         );
     }
 }
@@ -186,7 +183,7 @@ 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 config = Config::new(None, None, None, false);
-    assert_eq!(Ok(()), admin.write_config(config));
+    assert_ok!((), admin.write_config(config));
 
     configure_totp(&admin, 1);
     check_totp_codes(admin.deref(), 1, TotpTimestampSize::U32);
@@ -204,7 +201,7 @@ fn totp_no_pin(device: DeviceWrapper) {
 fn totp_no_pin_64(device: Pro) {
     let admin = make_admin_test_device(device);
     let config = Config::new(None, None, None, false);
-    assert_eq!(Ok(()), admin.write_config(config));
+    assert_ok!((), admin.write_config(config));
 
     configure_totp(&admin, 1);
     check_totp_codes(admin.deref(), 1, TotpTimestampSize::U64);
@@ -221,13 +218,13 @@ fn totp_pin(device: DeviceWrapper) {
     // TODO: this test may fail due to bad timing --> find solution
     let admin = make_admin_test_device(device);
     let config = Config::new(None, None, None, true);
-    assert_eq!(Ok(()), admin.write_config(config));
+    assert_ok!((), admin.write_config(config));
 
     configure_totp(&admin, 1);
     let user = admin.device().authenticate_user(USER_PASSWORD).unwrap();
     check_totp_codes(&user, 1, TotpTimestampSize::U32);
 
-    assert!(user.device().get_totp_code(1).is_err());
+    assert_cmd_err!(CommandError::NotAuthorized, user.device().get_totp_code(1));
 }
 
 #[test_device]
@@ -235,68 +232,64 @@ fn totp_pin(device: DeviceWrapper) {
 fn totp_pin_64(device: Pro) {
     let admin = make_admin_test_device(device);
     let config = Config::new(None, None, None, true);
-    assert_eq!(Ok(()), admin.write_config(config));
+    assert_ok!((), admin.write_config(config));
 
     configure_totp(&admin, 1);
     let user = admin.device().authenticate_user(USER_PASSWORD).unwrap();
     check_totp_codes(&user, 1, TotpTimestampSize::U64);
 
-    assert!(user.device().get_totp_code(1).is_err());
+    assert_cmd_err!(CommandError::NotAuthorized, user.device().get_totp_code(1));
 }
 
 #[test_device]
 fn totp_slot_name(device: DeviceWrapper) {
     let admin = make_admin_test_device(device);
     let slot_data = OtpSlotData::new(1, "test-totp", TOTP_SECRET, OtpMode::EightDigits);
-    assert_eq!(Ok(()), admin.write_totp_slot(slot_data, 0));
+    assert_ok!((), admin.write_totp_slot(slot_data, 0));
 
     let device = admin.device();
     let result = device.get_totp_slot_name(1);
-    assert!(result.is_ok());
-    assert_eq!("test-totp", result.unwrap());
+    assert_ok!("test-totp", result);
     let result = device.get_totp_slot_name(16);
-    assert_eq!(CommandError::InvalidSlot, result.unwrap_err());
+    assert_lib_err!(LibraryError::InvalidSlot, result);
 }
 
 #[test_device]
 fn totp_error(device: DeviceWrapper) {
     let admin = make_admin_test_device(device);
     let slot_data = OtpSlotData::new(1, "", TOTP_SECRET, OtpMode::SixDigits);
-    assert_eq!(
-        Err(CommandError::NoName),
-        admin.write_totp_slot(slot_data, 0)
-    );
+    assert_cmd_err!(CommandError::NoName, admin.write_totp_slot(slot_data, 0));
     let slot_data = OtpSlotData::new(20, "test", TOTP_SECRET, OtpMode::SixDigits);
-    assert_eq!(
-        Err(CommandError::InvalidSlot),
+    assert_lib_err!(
+        LibraryError::InvalidSlot,
         admin.write_totp_slot(slot_data, 0)
     );
     let slot_data = OtpSlotData::new(4, "test", "foobar", OtpMode::SixDigits);
-    assert_eq!(
-        Err(CommandError::InvalidHexString),
+    assert_lib_err!(
+        LibraryError::InvalidHexString,
         admin.write_totp_slot(slot_data, 0)
     );
     let code = admin.get_totp_code(20);
-    assert_eq!(CommandError::InvalidSlot, code.unwrap_err());
+    assert_lib_err!(LibraryError::InvalidSlot, code);
 }
 
 #[test_device]
 fn totp_erase(device: DeviceWrapper) {
     let admin = make_admin_test_device(device);
     let config = Config::new(None, None, None, false);
-    assert_eq!(Ok(()), admin.write_config(config));
+    assert_ok!((), admin.write_config(config));
     let slot_data = OtpSlotData::new(1, "test1", TOTP_SECRET, OtpMode::SixDigits);
-    assert_eq!(Ok(()), admin.write_totp_slot(slot_data, 0));
+    assert_ok!((), admin.write_totp_slot(slot_data, 0));
     let slot_data = OtpSlotData::new(2, "test2", TOTP_SECRET, OtpMode::SixDigits);
-    assert_eq!(Ok(()), admin.write_totp_slot(slot_data, 0));
+    assert_ok!((), admin.write_totp_slot(slot_data, 0));
 
-    assert_eq!(Ok(()), admin.erase_totp_slot(1));
+    assert_ok!((), admin.erase_totp_slot(1));
 
     let device = admin.device();
     let result = device.get_totp_slot_name(1);
-    assert_eq!(CommandError::SlotNotProgrammed, result.unwrap_err());
+    assert_cmd_err!(CommandError::SlotNotProgrammed, result);
     let result = device.get_totp_code(1);
-    assert_eq!(CommandError::SlotNotProgrammed, result.unwrap_err());
+    assert_cmd_err!(CommandError::SlotNotProgrammed, result);
 
     assert_eq!("test2", device.get_totp_slot_name(2).unwrap());
 }
diff --git a/nitrokey/tests/pws.rs b/nitrokey/tests/pws.rs
index fbcc0c1..df99e1c 100644
--- a/nitrokey/tests/pws.rs
+++ b/nitrokey/tests/pws.rs
@@ -1,18 +1,23 @@
+// Copyright (C) 2018-2019 Robin Krahl <robin.krahl@ireas.org>
+// SPDX-License-Identifier: MIT
+
 mod util;
 
 use std::ffi::CStr;
 
 use libc::{c_int, c_void, free};
-use nitrokey::{CommandError, Device, GetPasswordSafe, PasswordSafe, SLOT_COUNT};
+use nitrokey::{
+    CommandError, Device, Error, GetPasswordSafe, LibraryError, PasswordSafe, SLOT_COUNT,
+};
 use nitrokey_sys;
 use nitrokey_test::test as test_device;
 
 use crate::util::{ADMIN_PASSWORD, USER_PASSWORD};
 
-fn get_slot_name_direct(slot: u8) -> Result<String, CommandError> {
+fn get_slot_name_direct(slot: u8) -> Result<String, Error> {
     let ptr = unsafe { nitrokey_sys::NK_get_password_safe_slot_name(slot) };
     if ptr.is_null() {
-        return Err(CommandError::Undefined);
+        return Err(Error::UnexpectedError);
     }
     let s = unsafe { CStr::from_ptr(ptr).to_string_lossy().into_owned() };
     unsafe { free(ptr as *mut c_void) };
@@ -21,7 +26,7 @@ fn get_slot_name_direct(slot: u8) -> Result<String, CommandError> {
             let error = unsafe { nitrokey_sys::NK_get_last_command_status() } as c_int;
             match error {
                 0 => Ok(s),
-                other => Err(CommandError::from(other)),
+                other => Err(Error::from(other)),
             }
         }
         false => Ok(s),
@@ -37,11 +42,15 @@ where
 
 #[test_device]
 fn enable(device: DeviceWrapper) {
-    assert!(device
-        .get_password_safe(&(USER_PASSWORD.to_owned() + "123"))
-        .is_err());
+    assert_cmd_err!(
+        CommandError::WrongPassword,
+        device.get_password_safe(&(USER_PASSWORD.to_owned() + "123"))
+    );
     assert!(device.get_password_safe(USER_PASSWORD).is_ok());
-    assert!(device.get_password_safe(ADMIN_PASSWORD).is_err());
+    assert_cmd_err!(
+        CommandError::WrongPassword,
+        device.get_password_safe(ADMIN_PASSWORD)
+    );
     assert!(device.get_password_safe(USER_PASSWORD).is_ok());
 }
 
@@ -49,35 +58,35 @@ fn enable(device: DeviceWrapper) {
 fn drop(device: DeviceWrapper) {
     {
         let pws = get_pws(&device);
-        assert_eq!(Ok(()), pws.write_slot(1, "name", "login", "password"));
+        assert_ok!((), pws.write_slot(1, "name", "login", "password"));
         assert_eq!("name", pws.get_slot_name(1).unwrap());
         let result = get_slot_name_direct(1);
-        assert_eq!(Ok(String::from("name")), result);
+        assert_ok!(String::from("name"), result);
     }
     let result = get_slot_name_direct(1);
-    assert_eq!(Ok(String::from("name")), result);
-    assert_eq!(Ok(()), device.lock());
+    assert_ok!(String::from("name"), result);
+    assert_ok!((), device.lock());
     let result = get_slot_name_direct(1);
-    assert_eq!(Err(CommandError::NotAuthorized), result);
+    assert_cmd_err!(CommandError::NotAuthorized, result);
 }
 
 #[test_device]
 fn get_status(device: DeviceWrapper) {
     let pws = get_pws(&device);
     for i in 0..SLOT_COUNT {
-        assert_eq!(Ok(()), pws.erase_slot(i), "Could not erase slot {}", i);
+        assert_ok!((), pws.erase_slot(i));
     }
     let status = pws.get_slot_status().unwrap();
     assert_eq!(status, [false; SLOT_COUNT as usize]);
 
-    assert_eq!(Ok(()), pws.write_slot(1, "name", "login", "password"));
+    assert_ok!((), pws.write_slot(1, "name", "login", "password"));
     let status = pws.get_slot_status().unwrap();
     for i in 0..SLOT_COUNT {
         assert_eq!(i == 1, status[i as usize]);
     }
 
     for i in 0..SLOT_COUNT {
-        assert_eq!(Ok(()), pws.write_slot(i, "name", "login", "password"));
+        assert_ok!((), pws.write_slot(i, "name", "login", "password"));
     }
     let status = pws.get_slot_status().unwrap();
     assert_eq!(status, [true; SLOT_COUNT as usize]);
@@ -86,76 +95,61 @@ fn get_status(device: DeviceWrapper) {
 #[test_device]
 fn get_data(device: DeviceWrapper) {
     let pws = get_pws(&device);
-    assert_eq!(Ok(()), pws.write_slot(1, "name", "login", "password"));
+    assert_ok!((), pws.write_slot(1, "name", "login", "password"));
     assert_eq!("name", pws.get_slot_name(1).unwrap());
     assert_eq!("login", pws.get_slot_login(1).unwrap());
     assert_eq!("password", pws.get_slot_password(1).unwrap());
 
-    assert_eq!(Ok(()), pws.erase_slot(1));
-    assert_eq!(Err(CommandError::SlotNotProgrammed), pws.get_slot_name(1));
-    assert_eq!(Err(CommandError::SlotNotProgrammed), pws.get_slot_login(1));
-    assert_eq!(
-        Err(CommandError::SlotNotProgrammed),
-        pws.get_slot_password(1)
-    );
+    assert_ok!((), pws.erase_slot(1));
+    assert_cmd_err!(CommandError::SlotNotProgrammed, pws.get_slot_name(1));
+    assert_cmd_err!(CommandError::SlotNotProgrammed, pws.get_slot_login(1));
+    assert_cmd_err!(CommandError::SlotNotProgrammed, pws.get_slot_password(1));
 
     let name = "with å";
     let login = "pär@test.com";
     let password = "'i3lJc[09?I:,[u7dWz9";
-    assert_eq!(Ok(()), pws.write_slot(1, name, login, password));
+    assert_ok!((), pws.write_slot(1, name, login, password));
     assert_eq!(name, pws.get_slot_name(1).unwrap());
     assert_eq!(login, pws.get_slot_login(1).unwrap());
     assert_eq!(password, pws.get_slot_password(1).unwrap());
 
-    assert_eq!(
-        Err(CommandError::InvalidSlot),
-        pws.get_slot_name(SLOT_COUNT)
-    );
-    assert_eq!(
-        Err(CommandError::InvalidSlot),
-        pws.get_slot_login(SLOT_COUNT)
-    );
-    assert_eq!(
-        Err(CommandError::InvalidSlot),
-        pws.get_slot_password(SLOT_COUNT)
-    );
+    assert_lib_err!(LibraryError::InvalidSlot, pws.get_slot_name(SLOT_COUNT));
+    assert_lib_err!(LibraryError::InvalidSlot, pws.get_slot_login(SLOT_COUNT));
+    assert_lib_err!(LibraryError::InvalidSlot, pws.get_slot_password(SLOT_COUNT));
 }
 
 #[test_device]
 fn write(device: DeviceWrapper) {
     let pws = get_pws(&device);
 
-    assert_eq!(
-        Err(CommandError::InvalidSlot),
+    assert_lib_err!(
+        LibraryError::InvalidSlot,
         pws.write_slot(SLOT_COUNT, "name", "login", "password")
     );
 
-    assert_eq!(Ok(()), pws.write_slot(0, "", "login", "password"));
-    assert_eq!(Err(CommandError::SlotNotProgrammed), pws.get_slot_name(0));
-    assert_eq!(Ok(String::from("login")), pws.get_slot_login(0));
-    assert_eq!(Ok(String::from("password")), pws.get_slot_password(0));
-
-    assert_eq!(Ok(()), pws.write_slot(0, "name", "", "password"));
-    assert_eq!(Ok(String::from("name")), pws.get_slot_name(0));
-    assert_eq!(Err(CommandError::SlotNotProgrammed), pws.get_slot_login(0));
-    assert_eq!(Ok(String::from("password")), pws.get_slot_password(0));
-
-    assert_eq!(Ok(()), pws.write_slot(0, "name", "login", ""));
-    assert_eq!(Ok(String::from("name")), pws.get_slot_name(0));
-    assert_eq!(Ok(String::from("login")), pws.get_slot_login(0));
-    assert_eq!(
-        Err(CommandError::SlotNotProgrammed),
-        pws.get_slot_password(0)
-    );
+    assert_ok!((), pws.write_slot(0, "", "login", "password"));
+    assert_cmd_err!(CommandError::SlotNotProgrammed, pws.get_slot_name(0));
+    assert_ok!(String::from("login"), pws.get_slot_login(0));
+    assert_ok!(String::from("password"), pws.get_slot_password(0));
+
+    assert_ok!((), pws.write_slot(0, "name", "", "password"));
+    assert_ok!(String::from("name"), pws.get_slot_name(0));
+    assert_cmd_err!(CommandError::SlotNotProgrammed, pws.get_slot_login(0));
+    assert_ok!(String::from("password"), pws.get_slot_password(0));
+
+    assert_ok!((), pws.write_slot(0, "name", "login", ""));
+    assert_ok!(String::from("name"), pws.get_slot_name(0));
+    assert_ok!(String::from("login"), pws.get_slot_login(0));
+    assert_cmd_err!(CommandError::SlotNotProgrammed, pws.get_slot_password(0));
 }
 
 #[test_device]
 fn erase(device: DeviceWrapper) {
     let pws = get_pws(&device);
-    assert_eq!(Err(CommandError::InvalidSlot), pws.erase_slot(SLOT_COUNT));
+    assert_lib_err!(LibraryError::InvalidSlot, pws.erase_slot(SLOT_COUNT));
 
-    assert_eq!(Ok(()), pws.write_slot(0, "name", "login", "password"));
-    assert_eq!(Ok(()), pws.erase_slot(0));
-    assert_eq!(Ok(()), pws.erase_slot(0));
-    assert_eq!(Err(CommandError::SlotNotProgrammed), pws.get_slot_name(0));
+    assert_ok!((), pws.write_slot(0, "name", "login", "password"));
+    assert_ok!((), pws.erase_slot(0));
+    assert_ok!((), pws.erase_slot(0));
+    assert_cmd_err!(CommandError::SlotNotProgrammed, pws.get_slot_name(0));
 }
diff --git a/nitrokey/tests/util/mod.rs b/nitrokey/tests/util/mod.rs
index cbf6b93..49ec13e 100644
--- a/nitrokey/tests/util/mod.rs
+++ b/nitrokey/tests/util/mod.rs
@@ -1,2 +1,86 @@
+// Copyright (C) 2018-2019 Robin Krahl <robin.krahl@ireas.org>
+// SPDX-License-Identifier: MIT
+
 pub static ADMIN_PASSWORD: &str = "12345678";
 pub static USER_PASSWORD: &str = "123456";
+
+#[macro_export]
+macro_rules! assert_ok {
+    ($left:expr, $right:expr) => {{
+        match &$right {
+            Ok(right) => match &$left {
+                left => {
+                    if !(*left == *right) {
+                        panic!(
+                            r#"assertion failed: `(left == right)`
+  left: `{:?}`,
+ right: `{:?}`"#,
+                            left, right
+                        )
+                    }
+                }
+            },
+            Err(right_err) => panic!(
+                r#"assertion failed: `(left == right)`
+  left: `Ok({:?})`,
+ right: `Err({:?})`"#,
+                $left, right_err
+            ),
+        }
+    }};
+}
+
+#[macro_export]
+macro_rules! assert_err {
+    ($err:path, $left:expr, $right:expr) => {
+        match &$right {
+            Err($err(ref right_err)) => match &$left {
+                left_err => {
+                    if !(*left_err == *right_err) {
+                        panic!(
+                            r#"assertion failed: `(left == right)`
+  left: `{:?}`,
+ right: `{:?}`"#,
+                            left_err, right_err
+                        )
+                    }
+                }
+            },
+            Err(ref right_err) => panic!(
+                r#"assertion failed: `(left == right)`
+  left: `{:?}`,
+ right: `{:?}`"#,
+                $err($left),
+                right_err
+            ),
+            Ok(right_ok) => panic!(
+                r#"assertion failed: `(left == right)`
+  left: `Err({:?})`,
+ right: `Ok({:?})`"#,
+                $err($left),
+                right_ok
+            ),
+        }
+    };
+}
+
+#[macro_export]
+macro_rules! assert_cmd_err {
+    ($left:expr, $right:expr) => {
+        assert_err!(::nitrokey::Error::CommandError, $left, $right);
+    };
+}
+
+#[macro_export]
+macro_rules! assert_cmu_err {
+    ($left:expr, $right:expr) => {
+        assert_err!(::nitrokey::Error::CommunicationError, $left, $right);
+    };
+}
+
+#[macro_export]
+macro_rules! assert_lib_err {
+    ($left:expr, $right:expr) => {
+        assert_err!(::nitrokey::Error::LibraryError, $left, $right);
+    };
+}