aboutsummaryrefslogtreecommitdiff
path: root/src/commands.rs
blob: a2b60045d40235163634211d432fe8322420177d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
// commands.rs

// *************************************************************************
// * Copyright (C) 2018-2020 Daniel Mueller (deso@posteo.net)              *
// *                                                                       *
// * This program is free software: you can redistribute it and/or modify  *
// * it under the terms of the GNU General Public License as published by  *
// * the Free Software Foundation, either version 3 of the License, or     *
// * (at your option) any later version.                                   *
// *                                                                       *
// * This program is distributed in the hope that it will be useful,       *
// * but WITHOUT ANY WARRANTY; without even the implied warranty of        *
// * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
// * GNU General Public License for more details.                          *
// *                                                                       *
// * You should have received a copy of the GNU General Public License     *
// * along with this program.  If not, see <http://www.gnu.org/licenses/>. *
// *************************************************************************

use std::fmt;
use std::mem;
use std::result;
use std::thread;
use std::time;
use std::u8;

use libc::sync;

use nitrokey::ConfigureOtp;
use nitrokey::Device;
use nitrokey::GenerateOtp;
use nitrokey::GetPasswordSafe;

use crate::args;
use crate::error;
use crate::error::Error;
use crate::pinentry;
use crate::ExecCtx;
use crate::Result;

/// Create an `error::Error` with an error message of the format `msg: err`.
fn get_error(msg: &'static str, err: nitrokey::Error) -> Error {
  Error::NitrokeyError(Some(msg), err)
}

/// Set `libnitrokey`'s log level based on the execution context's verbosity.
fn set_log_level(ctx: &mut ExecCtx<'_>) {
  let log_lvl = match ctx.verbosity {
    // The error log level is what libnitrokey uses by default. As such,
    // there is no harm in us setting that as well when the user did not
    // ask for higher verbosity.
    0 => nitrokey::LogLevel::Error,
    1 => nitrokey::LogLevel::Warning,
    2 => nitrokey::LogLevel::Info,
    3 => nitrokey::LogLevel::DebugL1,
    4 => nitrokey::LogLevel::Debug,
    _ => nitrokey::LogLevel::DebugL2,
  };
  nitrokey::set_log_level(log_lvl);
}

/// Connect to any Nitrokey device and do something with it.
fn with_device<F>(ctx: &mut ExecCtx<'_>, op: F) -> Result<()>
where
  F: FnOnce(&mut ExecCtx<'_>, nitrokey::DeviceWrapper<'_>) -> Result<()>,
{
  let mut manager = nitrokey::take()?;
  set_log_level(ctx);

  let device = match ctx.model {
    Some(model) => manager.connect_model(model.into()).map_err(|_| {
      let error = format!("Nitrokey {} device not found", model.as_user_facing_str());
      Error::Error(error)
    })?,
    None => manager
      .connect()
      .map_err(|_| Error::from("Nitrokey device not found"))?,
  };

  op(ctx, device)
}

/// Connect to a Nitrokey Storage device and do something with it.
fn with_storage_device<F>(ctx: &mut ExecCtx<'_>, op: F) -> Result<()>
where
  F: FnOnce(&mut ExecCtx<'_>, nitrokey::Storage<'_>) -> Result<()>,
{
  let mut manager = nitrokey::take()?;
  set_log_level(ctx);

  if let Some(model) = ctx.model {
    if model != args::DeviceModel::Storage {
      return Err(Error::from(
        "This command is only available on the Nitrokey Storage",
      ));
    }
  }

  let device = manager
    .connect_storage()
    .map_err(|_| Error::from("Nitrokey Storage device not found"))?;
  op(ctx, device)
}

/// Connect to any Nitrokey device, retrieve a password safe handle, and
/// do something with it.
fn with_password_safe<F>(ctx: &mut ExecCtx<'_>, mut op: F) -> Result<()>
where
  F: FnMut(&mut ExecCtx<'_>, nitrokey::PasswordSafe<'_, '_>) -> Result<()>,
{
  with_device(ctx, |ctx, mut device| {
    let pin_entry = pinentry::PinEntry::from(args::PinType::User, &device)?;
    try_with_pin_and_data(
      ctx,
      &pin_entry,
      "Could not access the password safe",
      (),
      move |ctx, _, pin| {
        let pws = device
          .get_password_safe(pin)
          .map_err(|err| ((), Error::from(err)))?;

        op(ctx, pws).map_err(|err| ((), err))
      },
    )
  })?;
  Ok(())
}

/// Authenticate the given device using the given PIN type and operation.
///
/// If an error occurs, the error message `msg` is used.
fn authenticate<'mgr, D, A, F>(
  ctx: &mut ExecCtx<'_>,
  device: D,
  pin_type: args::PinType,
  msg: &'static str,
  op: F,
) -> Result<A>
where
  D: Device<'mgr>,
  F: FnMut(&mut ExecCtx<'_>, D, &str) -> result::Result<A, (D, nitrokey::Error)>,
{
  let pin_entry = pinentry::PinEntry::from(pin_type, &device)?;

  try_with_pin_and_data(ctx, &pin_entry, msg, device, op)
}

/// Authenticate the given device with the user PIN.
fn authenticate_user<'mgr, T>(ctx: &mut ExecCtx<'_>, device: T) -> Result<nitrokey::User<'mgr, T>>
where
  T: Device<'mgr>,
{
  authenticate(
    ctx,
    device,
    args::PinType::User,
    "Could not authenticate as user",
    |_ctx, device, pin| device.authenticate_user(pin),
  )
}

/// Authenticate the given device with the admin PIN.
fn authenticate_admin<'mgr, T>(ctx: &mut ExecCtx<'_>, device: T) -> Result<nitrokey::Admin<'mgr, T>>
where
  T: Device<'mgr>,
{
  authenticate(
    ctx,
    device,
    args::PinType::Admin,
    "Could not authenticate as admin",
    |_ctx, device, pin| device.authenticate_admin(pin),
  )
}

/// Return a string representation of the given volume status.
fn get_volume_status(status: &nitrokey::VolumeStatus) -> &'static str {
  if status.active {
    if status.read_only {
      "read-only"
    } else {
      "active"
    }
  } else {
    "inactive"
  }
}

/// Try to execute the given function with a pin queried using pinentry.
///
/// This function will query the pin of the given type from the user
/// using pinentry.  It will then execute the given function.  If this
/// function returns a result, the result will be passed on.  If it
/// returns a `CommandError::WrongPassword`, the user will be asked
/// again to enter the pin.  Otherwise, this function returns an error
/// containing the given error message.  The user will have at most
/// three tries to get the pin right.
///
/// The data argument can be used to pass on data between the tries.  At
/// the first try, this function will call `op` with `data`.  At the
/// second or third try, it will call `op` with the data returned by the
/// previous call to `op`.
fn try_with_pin_and_data_with_pinentry<D, F, R, E>(
  ctx: &mut ExecCtx<'_>,
  pin_entry: &pinentry::PinEntry,
  msg: &'static str,
  data: D,
  mut op: F,
) -> Result<R>
where
  F: FnMut(&mut ExecCtx<'_>, D, &str) -> result::Result<R, (D, E)>,
  E: error::TryInto<nitrokey::Error>,
{
  let mut data = data;
  let mut retry = 3;
  let mut error_msg = None;
  loop {
    let pin = pinentry::inquire(ctx, pin_entry, pinentry::Mode::Query, error_msg)?;
    match op(ctx, data, &pin) {
      Ok(result) => return Ok(result),
      Err((new_data, err)) => match err.try_into() {
        Ok(err) => match err {
          nitrokey::Error::CommandError(nitrokey::CommandError::WrongPassword) => {
            pinentry::clear(pin_entry)?;
            retry -= 1;

            if retry > 0 {
              error_msg = Some("Wrong password, please reenter");
              data = new_data;
              continue;
            }
            return Err(get_error(msg, err));
          }
          err => return Err(get_error(msg, err)),
        },
        Err(err) => return Err(err),
      },
    };
  }
}

/// Try to execute the given function with a PIN.
fn try_with_pin_and_data<D, F, R, E>(
  ctx: &mut ExecCtx<'_>,
  pin_entry: &pinentry::PinEntry,
  msg: &'static str,
  data: D,
  mut op: F,
) -> Result<R>
where
  F: FnMut(&mut ExecCtx<'_>, D, &str) -> result::Result<R, (D, E)>,
  E: Into<Error> + error::TryInto<nitrokey::Error>,
{
  let pin = match pin_entry.pin_type() {
    // Ideally we would not clone here, but that would require us to
    // restrict op to work with an immutable ExecCtx, which is not
    // possible given that some clients print data.
    args::PinType::Admin => ctx.admin_pin.clone(),
    args::PinType::User => ctx.user_pin.clone(),
  };

  if let Some(pin) = pin {
    let pin = pin.to_str().ok_or_else(|| {
      Error::Error(format!(
        "{}: Failed to read PIN due to invalid Unicode data",
        msg
      ))
    })?;
    op(ctx, data, &pin).map_err(|(_, err)| err.into())
  } else {
    try_with_pin_and_data_with_pinentry(ctx, pin_entry, msg, data, op)
  }
}

/// Try to execute the given function with a pin queried using pinentry.
///
/// This function behaves exactly as `try_with_pin_and_data`, but
/// it refrains from passing any data to it.
fn try_with_pin<F, E>(
  ctx: &mut ExecCtx<'_>,
  pin_entry: &pinentry::PinEntry,
  msg: &'static str,
  mut op: F,
) -> Result<()>
where
  F: FnMut(&str) -> result::Result<(), E>,
  E: Into<Error> + error::TryInto<nitrokey::Error>,
{
  try_with_pin_and_data(ctx, pin_entry, msg, (), |_ctx, data, pin| {
    op(pin).map_err(|err| (data, err))
  })
}

/// Pretty print the status of a Nitrokey Storage.
fn print_storage_status(ctx: &mut ExecCtx<'_>, status: &nitrokey::StorageStatus) -> Result<()> {
  println!(
    ctx,
    r#"  Storage:
    SD card ID:        {id:#x}
    firmware:          {fw}
    storage keys:      {sk}
    volumes:
      unencrypted:     {vu}
      encrypted:       {ve}
      hidden:          {vh}"#,
    id = status.serial_number_sd_card,
    fw = if status.firmware_locked {
      "locked"
    } else {
      "unlocked"
    },
    sk = if status.stick_initialized {
      "created"
    } else {
      "not created"
    },
    vu = get_volume_status(&status.unencrypted_volume),
    ve = get_volume_status(&status.encrypted_volume),
    vh = get_volume_status(&status.hidden_volume),
  )?;
  Ok(())
}

/// Query and pretty print the status that is common to all Nitrokey devices.
fn print_status(
  ctx: &mut ExecCtx<'_>,
  model: &'static str,
  device: &nitrokey::DeviceWrapper<'_>,
) -> Result<()> {
  let serial_number = device
    .get_serial_number()
    .map_err(|err| get_error("Could not query the serial number", err))?;

  println!(
    ctx,
    r#"Status:
  model:             {model}
  serial number:     {id}
  firmware version:  {fwv}
  user retry count:  {urc}
  admin retry count: {arc}"#,
    model = model,
    id = serial_number,
    fwv = device.get_firmware_version()?,
    urc = device.get_user_retry_count()?,
    arc = device.get_admin_retry_count()?,
  )?;

  if let nitrokey::DeviceWrapper::Storage(device) = device {
    let status = device
      .get_storage_status()
      .map_err(|err| get_error("Getting Storage status failed", err))?;

    print_storage_status(ctx, &status)
  } else {
    Ok(())
  }
}

/// Inquire the status of the nitrokey.
pub fn status(ctx: &mut ExecCtx<'_>) -> Result<()> {
  with_device(ctx, |ctx, device| {
    let model = match device {
      nitrokey::DeviceWrapper::Pro(_) => "Pro",
      nitrokey::DeviceWrapper::Storage(_) => "Storage",
    };
    print_status(ctx, model, &device)
  })
}

/// List the attached Nitrokey devices.
pub fn list(ctx: &mut ExecCtx<'_>, no_connect: bool) -> Result<()> {
  set_log_level(ctx);

  let device_infos = nitrokey::list_devices()?;
  if device_infos.is_empty() {
    println!(ctx, "No Nitrokey device connected")?;
  } else {
    println!(ctx, "device path\tmodel\tserial number")?;
    let mut manager = nitrokey::take()?;

    for device_info in device_infos {
      let model = device_info
        .model
        .map(|m| m.to_string())
        .unwrap_or_else(|| "unknown".into());
      let serial_number = match device_info.serial_number {
        Some(serial_number) => serial_number.to_string(),
        None => {
          // Storage devices do not have the serial number present in
          // the device information. We have to connect to them to
          // retrieve the information.
          if no_connect {
            "N/A".to_string()
          } else {
            let device = manager.connect_path(device_info.path.clone())?;
            device.get_serial_number()?.to_string()
          }
        }
      };

      println!(ctx, "{}\t{}\t{}", device_info.path, model, serial_number)?;
    }
  }

  Ok(())
}

/// Perform a factory reset.
pub fn reset(ctx: &mut ExecCtx<'_>) -> Result<()> {
  with_device(ctx, |ctx, mut device| {
    let pin_entry = pinentry::PinEntry::from(args::PinType::Admin, &device)?;

    // To force the user to enter the admin PIN before performing a
    // factory reset, we clear the pinentry cache for the admin PIN.
    pinentry::clear(&pin_entry)?;

    try_with_pin(ctx, &pin_entry, "Factory reset failed", |pin| {
      device.factory_reset(&pin)?;
      // Work around for a timing issue between factory_reset and
      // build_aes_key, see
      // https://github.com/Nitrokey/nitrokey-storage-firmware/issues/80
      thread::sleep(time::Duration::from_secs(3));
      // Another work around for spurious WrongPassword returns of
      // build_aes_key after a factory reset on Pro devices.
      // https://github.com/Nitrokey/nitrokey-pro-firmware/issues/57
      let _ = device.get_user_retry_count();
      device.build_aes_key(nitrokey::DEFAULT_ADMIN_PIN)
    })
  })
}

/// Change the configuration of the unencrypted volume.
pub fn unencrypted_set(ctx: &mut ExecCtx<'_>, mode: args::UnencryptedVolumeMode) -> Result<()> {
  with_storage_device(ctx, |ctx, mut device| {
    let pin_entry = pinentry::PinEntry::from(args::PinType::Admin, &device)?;
    let mode = match mode {
      args::UnencryptedVolumeMode::ReadWrite => nitrokey::VolumeMode::ReadWrite,
      args::UnencryptedVolumeMode::ReadOnly => nitrokey::VolumeMode::ReadOnly,
    };

    // The unencrypted volume may reconnect, so be sure to flush caches to
    // disk.
    unsafe { sync() };

    try_with_pin(
      ctx,
      &pin_entry,
      "Changing unencrypted volume mode failed",
      |pin| device.set_unencrypted_volume_mode(&pin, mode),
    )
  })
}

/// Open the encrypted volume on the Nitrokey.
pub fn encrypted_open(ctx: &mut ExecCtx<'_>) -> Result<()> {
  with_storage_device(ctx, |ctx, mut device| {
    let pin_entry = pinentry::PinEntry::from(args::PinType::User, &device)?;

    // We may forcefully close a hidden volume, if active, so be sure to
    // flush caches to disk.
    unsafe { sync() };

    try_with_pin(ctx, &pin_entry, "Opening encrypted volume failed", |pin| {
      device.enable_encrypted_volume(&pin)
    })
  })
}

/// Close the previously opened encrypted volume.
pub fn encrypted_close(ctx: &mut ExecCtx<'_>) -> Result<()> {
  with_storage_device(ctx, |_ctx, mut device| {
    // Flush all filesystem caches to disk. We are mostly interested in
    // making sure that the encrypted volume on the Nitrokey we are
    // about to close is not closed while not all data was written to
    // it.
    unsafe { sync() };

    device
      .disable_encrypted_volume()
      .map_err(|err| get_error("Closing encrypted volume failed", err))
  })
}

/// Create a hidden volume.
pub fn hidden_create(ctx: &mut ExecCtx<'_>, slot: u8, start: u8, end: u8) -> Result<()> {
  with_storage_device(ctx, |ctx, mut device| {
    let pwd_entry = pinentry::PwdEntry::from(&device)?;
    let pwd = if let Some(pwd) = &ctx.password {
      pwd
        .to_str()
        .ok_or_else(|| Error::from("Failed to read password: invalid Unicode data found"))
        .map(ToOwned::to_owned)
    } else {
      pinentry::choose(ctx, &pwd_entry)
    }?;

    device
      .create_hidden_volume(slot, start, end, &pwd)
      .map_err(|err| get_error("Creating hidden volume failed", err))
  })
}

/// Open a hidden volume.
pub fn hidden_open(ctx: &mut ExecCtx<'_>) -> Result<()> {
  with_storage_device(ctx, |ctx, mut device| {
    let pwd_entry = pinentry::PwdEntry::from(&device)?;
    let pwd = if let Some(pwd) = &ctx.password {
      pwd
        .to_str()
        .ok_or_else(|| Error::from("Failed to read password: invalid Unicode data found"))
        .map(ToOwned::to_owned)
    } else {
      pinentry::inquire(ctx, &pwd_entry, pinentry::Mode::Query, None)
    }?;

    // We may forcefully close an encrypted volume, if active, so be sure
    // to flush caches to disk.
    unsafe { sync() };

    device
      .enable_hidden_volume(&pwd)
      .map_err(|err| get_error("Opening hidden volume failed", err))
  })
}

/// Close a previously opened hidden volume.
pub fn hidden_close(ctx: &mut ExecCtx<'_>) -> Result<()> {
  with_storage_device(ctx, |_ctx, mut device| {
    unsafe { sync() };

    device
      .disable_hidden_volume()
      .map_err(|err| get_error("Closing hidden volume failed", err))
  })
}

/// Return a String representation of the given Option.
fn format_option<T: fmt::Display>(option: Option<T>) -> String {
  match option {
    Some(value) => format!("{}", value),
    None => "not set".to_string(),
  }
}

/// Read the Nitrokey configuration.
pub fn config_get(ctx: &mut ExecCtx<'_>) -> Result<()> {
  with_device(ctx, |ctx, device| {
    let config = device
      .get_config()
      .map_err(|err| get_error("Could not get configuration", err))?;
    println!(
      ctx,
      r#"Config:
  numlock binding:          {nl}
  capslock binding:         {cl}
  scrollock binding:        {sl}
  require user PIN for OTP: {otp}"#,
      nl = format_option(config.numlock),
      cl = format_option(config.capslock),
      sl = format_option(config.scrollock),
      otp = config.user_password,
    )?;
    Ok(())
  })
}

/// Write the Nitrokey configuration.
pub fn config_set(ctx: &mut ExecCtx<'_>, args: args::ConfigSetArgs) -> Result<()> {
  let numlock = args::ConfigOption::try_from(args.no_numlock, args.numlock, "numlock")?;
  let capslock = args::ConfigOption::try_from(args.no_capslock, args.capslock, "capslock")?;
  let scrollock = args::ConfigOption::try_from(args.no_scrollock, args.scrollock, "scrollock")?;
  let otp_pin = if args.otp_pin {
    Some(true)
  } else if args.no_otp_pin {
    Some(false)
  } else {
    None
  };

  with_device(ctx, |ctx, device| {
    let mut device = authenticate_admin(ctx, device)?;
    let config = device
      .get_config()
      .map_err(|err| get_error("Could not get configuration", err))?;
    let config = nitrokey::Config {
      numlock: numlock.or(config.numlock),
      capslock: capslock.or(config.capslock),
      scrollock: scrollock.or(config.scrollock),
      user_password: otp_pin.unwrap_or(config.user_password),
    };
    device
      .write_config(config)
      .map_err(|err| get_error("Could not set configuration", err))
  })
}

/// Lock the Nitrokey device.
pub fn lock(ctx: &mut ExecCtx<'_>) -> Result<()> {
  with_device(ctx, |_ctx, mut device| {
    device
      .lock()
      .map_err(|err| get_error("Could not lock the device", err))
  })
}

fn get_otp<T>(slot: u8, algorithm: args::OtpAlgorithm, device: &mut T) -> Result<String>
where
  T: GenerateOtp,
{
  match algorithm {
    args::OtpAlgorithm::Hotp => device.get_hotp_code(slot),
    args::OtpAlgorithm::Totp => device.get_totp_code(slot),
  }
  .map_err(|err| get_error("Could not generate OTP", err))
}

fn get_unix_timestamp() -> Result<u64> {
  time::SystemTime::now()
    .duration_since(time::UNIX_EPOCH)
    .map_err(|_| Error::from("Current system time is before the Unix epoch"))
    .map(|duration| duration.as_secs())
}

/// Generate a one-time password on the Nitrokey device.
pub fn otp_get(
  ctx: &mut ExecCtx<'_>,
  slot: u8,
  algorithm: args::OtpAlgorithm,
  time: Option<u64>,
) -> Result<()> {
  with_device(ctx, |ctx, mut device| {
    if algorithm == args::OtpAlgorithm::Totp {
      device
        .set_time(
          match time {
            Some(time) => time,
            None => get_unix_timestamp()?,
          },
          true,
        )
        .map_err(|err| get_error("Could not set time", err))?;
    }
    let config = device
      .get_config()
      .map_err(|err| get_error("Could not get device configuration", err))?;
    let otp = if config.user_password {
      let mut user = authenticate_user(ctx, device)?;
      get_otp(slot, algorithm, &mut user)
    } else {
      get_otp(slot, algorithm, &mut device)
    }?;
    println!(ctx, "{}", otp)?;
    Ok(())
  })
}

/// Format a byte vector as a hex string.
fn format_bytes(bytes: &[u8]) -> String {
  bytes
    .iter()
    .map(|c| format!("{:02x}", c))
    .collect::<Vec<_>>()
    .join("")
}

/// Prepare an ASCII secret string for libnitrokey.
///
/// libnitrokey expects secrets as hexadecimal strings.  This function transforms an ASCII string
/// into a hexadecimal string or returns an error if the given string contains non-ASCII
/// characters.
fn prepare_ascii_secret(secret: &str) -> Result<String> {
  if secret.is_ascii() {
    Ok(format_bytes(&secret.as_bytes()))
  } else {
    Err(Error::from(
      "The given secret is not an ASCII string despite --format ascii being set",
    ))
  }
}

/// Prepare a base32 secret string for libnitrokey.
fn prepare_base32_secret(secret: &str) -> Result<String> {
  base32::decode(base32::Alphabet::RFC4648 { padding: false }, secret)
    .map(|vec| format_bytes(&vec))
    .ok_or_else(|| Error::from("Could not parse base32 secret"))
}

/// Configure a one-time password slot on the Nitrokey device.
pub fn otp_set(ctx: &mut ExecCtx<'_>, mut args: args::OtpSetArgs) -> Result<()> {
  let mut data = nitrokey::OtpSlotData {
    number: args.slot,
    name: mem::take(&mut args.name),
    secret: mem::take(&mut args.secret),
    mode: args.digits.into(),
    use_enter: false,
    token_id: None,
  };

  with_device(ctx, |ctx, device| {
    let secret = match args.format {
      args::OtpSecretFormat::Ascii => prepare_ascii_secret(&data.secret)?,
      args::OtpSecretFormat::Base32 => prepare_base32_secret(&data.secret)?,
      args::OtpSecretFormat::Hex => {
        // We need to ensure to provide a string with an even number of
        // characters in it, just because that's what libnitrokey
        // expects. So prepend a '0' if that is not the case.
        // TODO: This code can be removed once upstream issue #164
        //       (https://github.com/Nitrokey/libnitrokey/issues/164) is
        //       addressed.
        if data.secret.len() % 2 != 0 {
          data.secret.insert(0, '0')
        }
        data.secret
      }
    };
    let data = nitrokey::OtpSlotData { secret, ..data };
    let mut device = authenticate_admin(ctx, device)?;
    match args.algorithm {
      args::OtpAlgorithm::Hotp => device.write_hotp_slot(data, args.counter),
      args::OtpAlgorithm::Totp => device.write_totp_slot(data, args.time_window),
    }
    .map_err(|err| get_error("Could not write OTP slot", err))?;
    Ok(())
  })
}

/// Clear an OTP slot.
pub fn otp_clear(ctx: &mut ExecCtx<'_>, slot: u8, algorithm: args::OtpAlgorithm) -> Result<()> {
  with_device(ctx, |ctx, device| {
    let mut device = authenticate_admin(ctx, device)?;
    match algorithm {
      args::OtpAlgorithm::Hotp => device.erase_hotp_slot(slot),
      args::OtpAlgorithm::Totp => device.erase_totp_slot(slot),
    }
    .map_err(|err| get_error("Could not clear OTP slot", err))?;
    Ok(())
  })
}

fn print_otp_status(
  ctx: &mut ExecCtx<'_>,
  algorithm: args::OtpAlgorithm,
  device: &nitrokey::DeviceWrapper<'_>,
  all: bool,
) -> Result<()> {
  let mut slot: u8 = 0;
  loop {
    let result = match algorithm {
      args::OtpAlgorithm::Hotp => device.get_hotp_slot_name(slot),
      args::OtpAlgorithm::Totp => device.get_totp_slot_name(slot),
    };
    slot = match slot.checked_add(1) {
      Some(slot) => slot,
      None => {
        return Err(Error::from("Integer overflow when iterating OTP slots"));
      }
    };
    let name = match result {
      Ok(name) => name,
      Err(nitrokey::Error::LibraryError(nitrokey::LibraryError::InvalidSlot)) => return Ok(()),
      Err(nitrokey::Error::CommandError(nitrokey::CommandError::SlotNotProgrammed)) => {
        if all {
          "[not programmed]".to_string()
        } else {
          continue;
        }
      }
      Err(err) => return Err(get_error("Could not check OTP slot", err)),
    };
    println!(ctx, "{}\t{}\t{}", algorithm, slot - 1, name)?;
  }
}

/// Print the status of the OTP slots.
pub fn otp_status(ctx: &mut ExecCtx<'_>, all: bool) -> Result<()> {
  with_device(ctx, |ctx, device| {
    println!(ctx, "alg\tslot\tname")?;
    print_otp_status(ctx, args::OtpAlgorithm::Hotp, &device, all)?;
    print_otp_status(ctx, args::OtpAlgorithm::Totp, &device, all)?;
    Ok(())
  })
}

/// Clear the PIN stored by various operations.
pub fn pin_clear(ctx: &mut ExecCtx<'_>) -> Result<()> {
  with_device(ctx, |_ctx, device| {
    pinentry::clear(&pinentry::PinEntry::from(args::PinType::Admin, &device)?)?;
    pinentry::clear(&pinentry::PinEntry::from(args::PinType::User, &device)?)?;
    Ok(())
  })
}

/// Choose a PIN of the given type.
///
/// If the user has set the respective environment variable for the
/// given PIN type, it will be used.
fn choose_pin(ctx: &mut ExecCtx<'_>, pin_entry: &pinentry::PinEntry, new: bool) -> Result<String> {
  let new_pin = match pin_entry.pin_type() {
    args::PinType::Admin => {
      if new {
        &ctx.new_admin_pin
      } else {
        &ctx.admin_pin
      }
    }
    args::PinType::User => {
      if new {
        &ctx.new_user_pin
      } else {
        &ctx.user_pin
      }
    }
  };

  if let Some(new_pin) = new_pin {
    new_pin
      .to_str()
      .ok_or_else(|| Error::from("Failed to read PIN: invalid Unicode data found"))
      .map(ToOwned::to_owned)
  } else {
    pinentry::choose(ctx, pin_entry)
  }
}

/// Change a PIN.
pub fn pin_set(ctx: &mut ExecCtx<'_>, pin_type: args::PinType) -> Result<()> {
  with_device(ctx, |ctx, mut device| {
    let pin_entry = pinentry::PinEntry::from(pin_type, &device)?;
    let new_pin = choose_pin(ctx, &pin_entry, true)?;

    try_with_pin(
      ctx,
      &pin_entry,
      "Could not change the PIN",
      |current_pin| match pin_type {
        args::PinType::Admin => device.change_admin_pin(&current_pin, &new_pin),
        args::PinType::User => device.change_user_pin(&current_pin, &new_pin),
      },
    )?;

    // We just changed the PIN but confirmed the action with the old PIN,
    // which may have caused it to be cached. Since it no longer applies,
    // make sure to evict the corresponding entry from the cache.
    pinentry::clear(&pin_entry)
  })
}

/// Unblock and reset the user PIN.
pub fn pin_unblock(ctx: &mut ExecCtx<'_>) -> Result<()> {
  with_device(ctx, |ctx, mut device| {
    let pin_entry = pinentry::PinEntry::from(args::PinType::User, &device)?;
    let user_pin = choose_pin(ctx, &pin_entry, false)?;
    let pin_entry = pinentry::PinEntry::from(args::PinType::Admin, &device)?;

    try_with_pin(
      ctx,
      &pin_entry,
      "Could not unblock the user PIN",
      |admin_pin| device.unlock_user_pin(&admin_pin, &user_pin),
    )
  })
}

fn print_pws_data(
  ctx: &mut ExecCtx<'_>,
  description: &'static str,
  result: result::Result<String, nitrokey::Error>,
  quiet: bool,
) -> Result<()> {
  let value = result.map_err(|err| get_error("Could not access PWS slot", err))?;
  if quiet {
    println!(ctx, "{}", value)?;
  } else {
    println!(ctx, "{} {}", description, value)?;
  }
  Ok(())
}

fn check_slot(pws: &nitrokey::PasswordSafe<'_, '_>, slot: u8) -> Result<()> {
  if slot >= nitrokey::SLOT_COUNT {
    return Err(nitrokey::Error::from(nitrokey::LibraryError::InvalidSlot).into());
  }
  let status = pws
    .get_slot_status()
    .map_err(|err| get_error("Could not read PWS slot status", err))?;
  if status[slot as usize] {
    Ok(())
  } else {
    Err(get_error(
      "Could not access PWS slot",
      nitrokey::CommandError::SlotNotProgrammed.into(),
    ))
  }
}

/// Read a PWS slot.
pub fn pws_get(
  ctx: &mut ExecCtx<'_>,
  slot: u8,
  show_name: bool,
  show_login: bool,
  show_password: bool,
  quiet: bool,
) -> Result<()> {
  with_password_safe(ctx, |ctx, pws| {
    check_slot(&pws, slot)?;

    let show_all = !show_name && !show_login && !show_password;
    if show_all || show_name {
      print_pws_data(ctx, "name:    ", pws.get_slot_name(slot), quiet)?;
    }
    if show_all || show_login {
      print_pws_data(ctx, "login:   ", pws.get_slot_login(slot), quiet)?;
    }
    if show_all || show_password {
      print_pws_data(ctx, "password:", pws.get_slot_password(slot), quiet)?;
    }
    Ok(())
  })
}

/// Write a PWS slot.
pub fn pws_set(
  ctx: &mut ExecCtx<'_>,
  slot: u8,
  name: &str,
  login: &str,
  password: &str,
) -> Result<()> {
  with_password_safe(ctx, |_ctx, mut pws| {
    pws
      .write_slot(slot, name, login, password)
      .map_err(|err| get_error("Could not write PWS slot", err))
  })
}

/// Clear a PWS slot.
pub fn pws_clear(ctx: &mut ExecCtx<'_>, slot: u8) -> Result<()> {
  with_password_safe(ctx, |_ctx, mut pws| {
    pws
      .erase_slot(slot)
      .map_err(|err| get_error("Could not clear PWS slot", err))
  })
}

fn print_pws_slot(
  ctx: &mut ExecCtx<'_>,
  pws: &nitrokey::PasswordSafe<'_, '_>,
  slot: usize,
  programmed: bool,
) -> Result<()> {
  if slot > u8::MAX as usize {
    return Err(Error::from("Invalid PWS slot number"));
  }
  let slot = slot as u8;
  let name = if programmed {
    pws
      .get_slot_name(slot)
      .map_err(|err| get_error("Could not read PWS slot", err))?
  } else {
    "[not programmed]".to_string()
  };
  println!(ctx, "{}\t{}", slot, name)?;
  Ok(())
}

/// Print the status of all PWS slots.
pub fn pws_status(ctx: &mut ExecCtx<'_>, all: bool) -> Result<()> {
  with_password_safe(ctx, |ctx, pws| {
    let slots = pws
      .get_slot_status()
      .map_err(|err| get_error("Could not read PWS slot status", err))?;
    println!(ctx, "slot\tname")?;
    for (i, &value) in slots.iter().enumerate().filter(|(_, &value)| all || value) {
      print_pws_slot(ctx, &pws, i, value)?;
    }
    Ok(())
  })
}

#[cfg(test)]
mod tests {
  use super::*;

  #[test]
  fn prepare_secret_ascii() {
    let result = prepare_ascii_secret("12345678901234567890");
    assert_eq!(
      "3132333435363738393031323334353637383930".to_string(),
      result.unwrap()
    );
  }

  #[test]
  fn prepare_secret_non_ascii() {
    let result = prepare_ascii_secret("Österreich");
    assert!(result.is_err());
  }

  #[test]
  fn hex_string() {
    assert_eq!(format_bytes(&[b' ']), "20");
    assert_eq!(format_bytes(&[b' ', b' ']), "2020");
    assert_eq!(format_bytes(&[b'\n', b'\n']), "0a0a");
  }
}