aboutsummaryrefslogtreecommitdiff
path: root/NK_C_API.h
blob: c79b8a260204d6803b6e68297f78370e950f4b00 (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
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
/*
 * Copyright (c) 2015-2018 Nitrokey UG
 *
 * This file is part of libnitrokey.
 *
 * libnitrokey is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * any later version.
 *
 * libnitrokey 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 Lesser General Public License
 * along with libnitrokey. If not, see <http://www.gnu.org/licenses/>.
 *
 * SPDX-License-Identifier: LGPL-3.0
 */

#ifndef LIBNITROKEY_NK_C_API_H
#define LIBNITROKEY_NK_C_API_H

#include <stdbool.h>
#include <stdint.h>

#include "deprecated.h"

#ifdef _MSC_VER
#define NK_C_API __declspec(dllexport)
#else
#define NK_C_API
#endif

/**
 * \file
 *
 * C API for libnitrokey
 *
 * \mainpage
 *
 * **libnitrokey** provides access to Nitrokey Pro and Nitrokey Storage devices.
 * This documentation describes libnitrokey’s C API.  For a list of the
 * available functions, see the NK_C_API.h file.
 *
 * \section getting_started Example
 *
 * \code{.c}
 * #include <stdio.h>
 * #include <stdlib.h>
 * #include <libnitrokey/NK_C_API.h>
 *
 * int main(void)
 * {
 *         if (NK_login_auto() != 1) {
 *                 fprintf(stderr, "No Nitrokey found.\n");
 *                 return 1;
 *         }
 *
 *         NK_device_model model = NK_get_device_model();
 *         printf("Connected to ");
 *         switch (model) {
 *         case NK_PRO:
 *                 printf("a Nitrokey Pro");
 *                 break;
 *         case NK_STORAGE:
 *                 printf("a Nitrokey Storage");
 *                 break;
 *         case NK_LIBREM:
 *                 printf("a Librem Key");
 *                 break;
 *         default:
 *                 printf("an unsupported Nitrokey");
 *                 break;
 *         }
 *
 *         char* serial_number = NK_device_serial_number();
 *         if (serial_number)
 *             printf(" with serial number %s\n", serial_number);
 *         else
 *             printf(" -- could not query serial number!\n");
 *         free(serial_number);
 *
 *         NK_logout();
 *         return 0;
 * }
 * \endcode
 */

#ifdef __cplusplus
extern "C" {
#endif

  /**
   * The number of slots in the password safe.
   */
  extern const uint8_t NK_PWS_SLOT_COUNT;

  static const int MAXIMUM_STR_REPLY_LENGTH = 8192;

        /**
         * The Nitrokey device models supported by the API.
         */
        enum NK_device_model {
						/**
						 * Use, if no supported device is connected
						 */
        		NK_DISCONNECTED = 0,
            /**
             * Nitrokey Pro.
             */
            NK_PRO = 1,
            /**
             * Nitrokey Storage.
             */
            NK_STORAGE = 2,
            /**
             * Librem Key.
             */
            NK_LIBREM = 3
        };

        /**
	 * The connection info for a Nitrokey device as a linked list.
	 */
	struct NK_device_info {
		/**
		 * The model of the Nitrokey device.
		 */
		enum NK_device_model model;
		/**
		 * The USB device path for NK_connect_with_path.
		 */
		char* path;
		/**
		 * The serial number.
		 */
		char* serial_number;
		/**
		 * The pointer to the next element of the linked list or null
		 * if this is the last element in the list.
		 */
		struct NK_device_info* next;
	};

	/**
	 * Stores the common device status for all Nitrokey devices.
	 */
	struct NK_status {
		/**
		 * The major firmware version, e. g. 0 in v0.40.
		 */
		uint8_t firmware_version_major;
		/**
		 * The minor firmware version, e. g. 40 in v0.40.
		 */
		uint8_t firmware_version_minor;
		/**
		 * The serial number of the smart card.
		 */
		uint32_t serial_number_smart_card;
		/**
		 * The HOTP slot to generate a password from if the numlock
		 * key is pressed twice (slot 0-1, or any other value to
		 * disable the function).
		 */
		uint8_t config_numlock;
		/**
		 * The HOTP slot to generate a password from if the capslock
		 * key is pressed twice (slot 0-1, or any other value to
		 * disable the function).
		 */
		uint8_t config_capslock;
		/**
		 * The HOTP slot to generate a password from if the scrolllock
		 * key is pressed twice (slot 0-1, or any other value to
		 * disable the function).
		 */
		uint8_t config_scrolllock;
		/**
		 * Indicates whether the user password is required to generate
		 * an OTP value.
		 */
		bool otp_user_password;
	};

	/**
	 * Stores the status of a Storage device.
	 */
        struct NK_storage_status {
		/**
		 * Indicates whether the unencrypted volume is read-only.
		 */
		bool unencrypted_volume_read_only;
		/**
		 * Indicates whether the unencrypted volume is active.
		 */
		bool unencrypted_volume_active;
		/**
		 * Indicates whether the encrypted volume is read-only.
		 */
		bool encrypted_volume_read_only;
		/**
		 * Indicates whether the encrypted volume is active.
		 */
		bool encrypted_volume_active;
		/**
		 * Indicates whether the hidden volume is read-only.
		 */
		bool hidden_volume_read_only;
		/**
		 * Indicates whether the hidden volume is active.
		 */
		bool hidden_volume_active;
		/**
		 * The major firmware version, e. g. 0 in v0.40.
		 */
		uint8_t firmware_version_major;
		/**
		 * The minor firmware version, e. g. 40 in v0.40.
		 */
		uint8_t firmware_version_minor;
		/**
		 * Indicates whether the firmware is locked.
		 */
		bool firmware_locked;
		/**
		 * The serial number of the SD card in the Storage stick.
		 */
		uint32_t serial_number_sd_card;
		/**
		 * The serial number of the smart card in the Storage stick.
		 */
		uint32_t serial_number_smart_card;
		/**
		 * The number of remaining login attempts for the user PIN.
		 */
		uint8_t user_retry_count;
		/**
		 * The number of remaining login attempts for the admin PIN.
		 */
		uint8_t admin_retry_count;
		/**
		 * Indicates whether a new SD card was found.
		 */
		bool new_sd_card_found;
		/**
		 * Indicates whether the SD card is filled with random characters.
		 */
		bool filled_with_random;
		/**
		 * Indicates whether the stick has been initialized by generating
		 * the AES keys.
		 */
		bool stick_initialized;
        };

	/**
	 * Data about the usage of the SD card.
	 */
	struct NK_SD_usage_data {
		/**
		 * The minimum write level, as a percentage of the total card
		 * size.
		 */
		uint8_t write_level_min;
		/**
		 * The maximum write level, as a percentage of the total card
		 * size.
		 */
		uint8_t write_level_max;
	};

        /**
         * The general configuration of a Nitrokey device.
         */
        struct NK_config {
            /**
             * value in range [0-1] to send HOTP code from slot 'numlock' after double pressing numlock
             * or outside the range to disable this function
             */
            uint8_t numlock;
            /**
	     * similar to numlock but with capslock
             */
            uint8_t capslock;
            /**
	     * similar to numlock but with scrolllock
             */
            uint8_t scrolllock;
            /**
             * True to enable OTP PIN protection (require PIN each OTP code request)
             */
            bool enable_user_password;
            /**
             * Unused.
             */
            bool disable_user_password;
        };

   struct NK_storage_ProductionTest{
    uint8_t FirmwareVersion_au8[2];
    uint8_t FirmwareVersionInternal_u8;
    uint8_t SD_Card_Size_u8;
    uint32_t CPU_CardID_u32;
    uint32_t SmartCardID_u32;
    uint32_t SD_CardID_u32;
    uint8_t SC_UserPwRetryCount;
    uint8_t SC_AdminPwRetryCount;
    uint8_t SD_Card_ManufacturingYear_u8;
    uint8_t SD_Card_ManufacturingMonth_u8;
    uint16_t SD_Card_OEM_u16;
    uint16_t SD_WriteSpeed_u16;
    uint8_t SD_Card_Manufacturer_u8;
  };

  NK_C_API int NK_get_storage_production_info(struct NK_storage_ProductionTest * out);


/**
 * Set debug level of messages written on stderr
 * @param state state=True - most messages, state=False - only errors level
 */
	NK_C_API void NK_set_debug(bool state);

	/**
	 * Set debug level of messages written on stderr
	 * @param level (int) 0-lowest verbosity, 5-highest verbosity
	 */
	NK_C_API void NK_set_debug_level(const int level);

	/**
	 * Get the major library version, e. g. the 3 in v3.2.
	 * @return the major library version
	 */
	NK_C_API unsigned int NK_get_major_library_version();

	/**
	 * Get the minor library version, e. g. the 2 in v3.2.
	 * @return the minor library version
	 */
	NK_C_API unsigned int NK_get_minor_library_version();

	/**
	 * Get the library version as a string.  This is the output of
	 * `git describe --always` at compile time, for example "v3.3" or
	 * "v3.3-19-gaee920b".
	 * The return value is a string literal and must not be freed.
	 * @return the library version as a string
	 */
	NK_C_API const char* NK_get_library_version();

	/**
	 * Connect to device of given model. Currently library can be connected only to one device at once.
	 * @param device_model char 'S': Nitrokey Storage, 'P': Nitrokey Pro
	 * @return 1 if connected, 0 if wrong model or cannot connect
	 */
	NK_C_API int NK_login(const char *device_model);

	/**
	 * Connect to device of given model. Currently library can be connected only to one device at once.
	 * @param device_model NK_device_model: NK_PRO: Nitrokey Pro, NK_STORAGE: Nitrokey Storage, NK_LIBREM: Librem Key
	 * @return 1 if connected, 0 if wrong model or cannot connect
	 */
        NK_C_API int NK_login_enum(enum NK_device_model device_model);

	/**
	 * Connect to first available device, starting checking from Pro 1st to Storage 2nd.
	 * @return 1 if connected, 0 if wrong model or cannot connect
	 */
	NK_C_API int NK_login_auto();

	/**
	 * Disconnect from the device.
	 * @return command processing error code
	 */
	NK_C_API int NK_logout();

	/**
	 * Query the model of the connected device.
	 * Returns the model of the connected device or NK_DISCONNECTED.
	 *
	 * @return true if a device is connected and the out argument has been set
	 */
	NK_C_API enum NK_device_model NK_get_device_model();

	/**
	 * Return the debug status string. Debug purposes.  This function is
	 * deprecated in favor of NK_get_status_as_string.
	 * @return string representation of the status or an empty string
	 *         if the command failed
	 */
	DEPRECATED
	NK_C_API char * NK_status();

	/**
	 * Return the debug status string. Debug purposes.
	 * @return string representation of the status or an empty string
	 *         if the command failed
	 */
	NK_C_API char * NK_get_status_as_string();

	/**
	 * Get the stick status common to all Nitrokey devices and return the
	 * command processing error code.  If the code is zero, i. e. the
	 * command was successful, the storage status is written to the output
	 * pointer's target.  The output pointer must not be null.
	 *
	 * @param out the output pointer for the status
	 * @return command processing error code
	 */
	NK_C_API int NK_get_status(struct NK_status* out);

	/**
	 * Return the device's serial number string in hex.
	 * @return string device's serial number in hex
	 */
	NK_C_API char * NK_device_serial_number();

	/**
	 * Return the device's serial number string as an integer.  Use
         * NK_last_command_status to check for an error if this function
         * returns zero.
	 * @return device's serial number as an integer
	 */
	NK_C_API uint32_t NK_device_serial_number_as_u32();

	/**
	 * Get last command processing status. Useful for commands which returns the results of their own and could not return
	 * an error code.
	 * @return previous command processing error code
	 */
	NK_C_API uint8_t NK_get_last_command_status();

	/**
	 * Lock device - cancel any user device unlocking.
	 * @return command processing error code
	 */
	NK_C_API int NK_lock_device();

	/**
	 * Authenticates the user on USER privilages with user_password and sets user's temporary password on device to user_temporary_password.
	 * @param user_password char[25] current user password
	 * @param user_temporary_password char[25] user temporary password to be set on device for further communication (authentication command)
	 * @return command processing error code
	 */
	NK_C_API int NK_user_authenticate(const char* user_password, const char* user_temporary_password);

	/**
	 * Authenticates the user on ADMIN privilages with admin_password and sets user's temporary password on device to admin_temporary_password.
	 * @param admin_password char[25] current administrator PIN
	 * @param admin_temporary_password char[25] admin temporary password to be set on device for further communication (authentication command)
	 * @return command processing error code
	 */
	NK_C_API int NK_first_authenticate(const char* admin_password, const char* admin_temporary_password);

	/**
	 * Execute a factory reset.
	 * @param admin_password char[20] current administrator PIN
	 * @return command processing error code
	 */
	NK_C_API int NK_factory_reset(const char* admin_password);

	/**
	 * Generates AES key on the device
	 * @param admin_password char[20] current administrator PIN
	 * @return command processing error code
	 */
	NK_C_API int NK_build_aes_key(const char* admin_password);

	/**
	 * Unlock user PIN locked after 3 incorrect codes tries.
	 * @param admin_password char[20] current administrator PIN
	 * @return command processing error code
	 */
	NK_C_API int NK_unlock_user_password(const char *admin_password, const char *new_user_password);

	/**
	 * Write general config to the device
	 * @param numlock set value in range [0-1] to send HOTP code from slot 'numlock' after double pressing numlock
	 * or outside the range to disable this function
	 * @param capslock similar to numlock but with capslock
	 * @param scrolllock similar to numlock but with scrolllock
	 * @param enable_user_password set True to enable OTP PIN protection (require PIN each OTP code request)
	 * @param delete_user_password (unused)
	 * @param admin_temporary_password current admin temporary password
	 * @return command processing error code
	 */
	NK_C_API int NK_write_config(uint8_t numlock, uint8_t capslock, uint8_t scrolllock,
		bool enable_user_password, bool delete_user_password, const char *admin_temporary_password);

	/**
	 * Write general config to the device
	 * @param config the configuration data
	 * @param admin_temporary_password current admin temporary password
	 * @return command processing error code
	 */
	NK_C_API int NK_write_config_struct(struct NK_config config, const char *admin_temporary_password);

	/**
	 * Get currently set config - status of function Numlock/Capslock/Scrollock OTP sending and is enabled PIN protected OTP
         * The return value must be freed using NK_free_config.
	 * @see NK_write_config
	 * @return  uint8_t general_config[5]:
	 *            uint8_t numlock;
				  uint8_t capslock;
				  uint8_t scrolllock;
				  uint8_t enable_user_password;
				  uint8_t delete_user_password;

	 */
	NK_C_API uint8_t* NK_read_config();

        /**
         * Free a value returned by NK_read_config.  May be called with a NULL
         * argument.
         */
        NK_C_API void NK_free_config(uint8_t* config);

	/**
	 * Get currently set config and write it to the given pointer.
         * @see NK_read_config
	 * @see NK_write_config_struct
         * @param out a pointer to the struct that should be written to
	 * @return command processing error code
	 */
	NK_C_API int NK_read_config_struct(struct NK_config* out);

	//OTP

	/**
	 * Get name of given TOTP slot
	 * @param slot_number TOTP slot number, slot_number<15
	 * @return char[20] the name of the slot
	 */
	NK_C_API char * NK_get_totp_slot_name(uint8_t slot_number);

	/**
	 *
	 * @param slot_number HOTP slot number, slot_number<3
	 * @return char[20] the name of the slot
	 */
	NK_C_API char * NK_get_hotp_slot_name(uint8_t slot_number);

	/**
	 * Erase HOTP slot data from the device
	 * @param slot_number HOTP slot number, slot_number<3
	 * @param temporary_password admin temporary password
	 * @return command processing error code
	 */
	NK_C_API int NK_erase_hotp_slot(uint8_t slot_number, const char *temporary_password);

	/**
	 * Erase TOTP slot data from the device
	 * @param slot_number TOTP slot number, slot_number<15
	 * @param temporary_password admin temporary password
	 * @return command processing error code
	 */
	NK_C_API int NK_erase_totp_slot(uint8_t slot_number, const char *temporary_password);

	/**
	 * Write HOTP slot data to the device
	 * @param slot_number HOTP slot number, slot_number<3, 0-numbered
	 * @param slot_name char[15] desired slot name. C string (requires ending '\0'; 16 bytes).
	 * @param secret char[40] 160-bit or 320-bit (currently Pro v0.8 only) secret as a hex string. C string (requires ending '\0'; 41 bytes).
	 * See NitrokeyManager::is_320_OTP_secret_supported.
	 * @param hotp_counter uint32_t starting value of HOTP counter
	 * @param use_8_digits should returned codes be 6 (false) or 8 digits (true)
	 * @param use_enter press ENTER key after sending OTP code using double-pressed scroll/num/capslock
	 * @param use_tokenID @see token_ID
	 * @param token_ID @see https://openauthentication.org/token-specs/, 'Class A' section
	 * @param temporary_password char[25] admin temporary password
	 * @return command processing error code
	 */
	NK_C_API int NK_write_hotp_slot(uint8_t slot_number, const char *slot_name, const char *secret, uint64_t hotp_counter,
		bool use_8_digits, bool use_enter, bool use_tokenID, const char *token_ID,
		const char *temporary_password);

	/**
	 * Write TOTP slot data to the device
	 * @param slot_number TOTP slot number, slot_number<15, 0-numbered
	 * @param slot_name char[15] desired slot name. C string (requires ending '\0'; 16 bytes).
	 * @param secret char[40] 160-bit or 320-bit (currently Pro v0.8 only) secret as a hex string. C string (requires ending '\0'; 41 bytes).
	 * See NitrokeyManager::is_320_OTP_secret_supported.
	 * @param time_window uint16_t time window for this TOTP
	 * @param use_8_digits should returned codes be 6 (false) or 8 digits (true)
	 * @param use_enter press ENTER key after sending OTP code using double-pressed scroll/num/capslock
	 * @param use_tokenID @see token_ID
	 * @param token_ID @see https://openauthentication.org/token-specs/, 'Class A' section
	 * @param temporary_password char[20] admin temporary password
	 * @return command processing error code
	 */
	NK_C_API int NK_write_totp_slot(uint8_t slot_number, const char *slot_name, const char *secret, uint16_t time_window,
		bool use_8_digits, bool use_enter, bool use_tokenID, const char *token_ID,
		const char *temporary_password);

	/**
	 * Get HOTP code from the device
	 * @param slot_number HOTP slot number, slot_number<3
	 * @return HOTP code
	 */
	NK_C_API char * NK_get_hotp_code(uint8_t slot_number);

	/**
	 * Get HOTP code from the device (PIN protected)
	 * @param slot_number HOTP slot number, slot_number<3
	 * @param user_temporary_password char[25] user temporary password if PIN protected OTP codes are enabled,
	 * otherwise should be set to empty string - ''
	 * @return HOTP code
	 */
	NK_C_API char * NK_get_hotp_code_PIN(uint8_t slot_number, const char *user_temporary_password);

	/**
	 * Get TOTP code from the device
	 * @param slot_number TOTP slot number, slot_number<15
	 * @param challenge TOTP challenge -- unused
	 * @param last_totp_time last time -- unused
	 * @param last_interval last interval --unused
	 * @return TOTP code
	 */
	NK_C_API char * NK_get_totp_code(uint8_t slot_number, uint64_t challenge, uint64_t last_totp_time,
		uint8_t last_interval);

	/**
	 * Get TOTP code from the device (PIN protected)
	 * @param slot_number TOTP slot number, slot_number<15
	 * @param challenge TOTP challenge -- unused
	 * @param last_totp_time last time -- unused
	 * @param last_interval last interval -- unused
	 * @param user_temporary_password char[25] user temporary password if PIN protected OTP codes are enabled,
	 * otherwise should be set to empty string - ''
	 * @return TOTP code
	 */
	NK_C_API char * NK_get_totp_code_PIN(uint8_t slot_number, uint64_t challenge,
		uint64_t last_totp_time, uint8_t last_interval,
		const char *user_temporary_password);

	/**
	 * Set time on the device (for TOTP requests)
	 * @param time seconds in unix epoch (from 01.01.1970)
	 * @return command processing error code
	 */
	NK_C_API int NK_totp_set_time(uint64_t time);

	/**
	 * Set the device time used for TOTP to the given time.  Contrary to
	 * {@code set_time(uint64_t)}, this command fails if {@code old_time}
	 * &gt; {@code time} or if {@code old_time} is zero (where {@code
	 * old_time} is the current time on the device).
	 *
	 * @param time new device time as Unix timestamp (seconds since
	 *        1970-01-01)
	 * @return command processing error code
	 */
	NK_C_API int NK_totp_set_time_soft(uint64_t time);

	// NK_totp_get_time is deprecated -- use NK_totp_set_time_soft instead
	DEPRECATED
	NK_C_API int NK_totp_get_time();

	//passwords
	/**
	 * Change administrator PIN
	 * @param current_PIN char[25] current PIN
	 * @param new_PIN char[25] new PIN
	 * @return command processing error code
	 */
	NK_C_API int NK_change_admin_PIN(const char *current_PIN, const char *new_PIN);

	/**
	 * Change user PIN
	 * @param current_PIN char[25] current PIN
	 * @param new_PIN char[25] new PIN
	 * @return command processing error code
	*/
	NK_C_API int NK_change_user_PIN(const char *current_PIN, const char *new_PIN);


	/**
	 * Get retry count of user PIN
	 * @return user PIN retry count
	 */
	NK_C_API uint8_t NK_get_user_retry_count();

	/**
	 * Get retry count of admin PIN
	 * @return admin PIN retry count
	 */
	NK_C_API uint8_t NK_get_admin_retry_count();
	//password safe

	/**
	 * Enable password safe access
	 * @param user_pin char[30] current user PIN
	 * @return command processing error code
	 */
	NK_C_API int NK_enable_password_safe(const char *user_pin);

	/**
	 * Get password safe slots' status
         * The return value must be freed using NK_free_password_safe_slot_status.
	 * @return uint8_t[16] slot statuses - each byte represents one slot with 0 (not programmed) and 1 (programmed)
	 */
	NK_C_API uint8_t * NK_get_password_safe_slot_status();

        /**
         * Free a value returned by NK_get_password_safe_slot_status.  May be
         * called with a NULL argument.
         */
        NK_C_API void NK_free_password_safe_slot_status(uint8_t* status);

	/**
	 * Get password safe slot name
	 * @param slot_number password safe slot number, slot_number<16
	 * @return slot name
	 */
	NK_C_API char *NK_get_password_safe_slot_name(uint8_t slot_number);

	/**
	 * Get password safe slot login
	 * @param slot_number password safe slot number, slot_number<16
	 * @return login from the PWS slot
	 */
	NK_C_API char *NK_get_password_safe_slot_login(uint8_t slot_number);

	/**
	 * Get the password safe slot password
	 * @param slot_number password safe slot number, slot_number<16
	 * @return password from the PWS slot
	 */
	NK_C_API char *NK_get_password_safe_slot_password(uint8_t slot_number);

	/**
	 * Write password safe data to the slot
	 * @param slot_number password safe slot number, slot_number<16
	 * @param slot_name char[11] name of the slot
	 * @param slot_login char[32] login string
	 * @param slot_password char[20] password string
	 * @return command processing error code
	 */
	NK_C_API int NK_write_password_safe_slot(uint8_t slot_number, const char *slot_name,
		const char *slot_login, const char *slot_password);

	/**
	 * Erase the password safe slot from the device
	 * @param slot_number password safe slot number, slot_number<16
	 * @return command processing error code
	 */
	NK_C_API int NK_erase_password_safe_slot(uint8_t slot_number);

	/**
	 * Check whether AES is supported by the device
	 * @return 0 for no and 1 for yes
	 */
	NK_C_API int NK_is_AES_supported(const char *user_password);

	/**
	 * Get device's major firmware version
	 * @return major part of the version number (e.g. 0 from 0.48, 0 from 0.7 etc.)
	 */
	NK_C_API uint8_t NK_get_major_firmware_version();

	/**
	 * Get device's minor firmware version
	 * @return minor part of the version number (e.g. 7 from 0.7, 48 from 0.48 etc.)
	 */
	NK_C_API uint8_t NK_get_minor_firmware_version();

  /**
   * Function to determine unencrypted volume PIN type
   * @param minor_firmware_version
   * @return Returns 1, if set unencrypted volume ro/rw pin type is User, 0 otherwise.
   */
	NK_C_API int NK_set_unencrypted_volume_rorw_pin_type_user();


	/**
	 * This command is typically run to initiate
	 * communication with the device (altough not required).
	 * It sets time on device and returns its current status
	 * - a combination of set_time and get_status_storage commands
	 * Storage only
	 * @param seconds_from_epoch date and time expressed in seconds
	 */
	NK_C_API int NK_send_startup(uint64_t seconds_from_epoch);

	/**
	 * Unlock encrypted volume.
	 * Storage only
	 * @param user_pin user pin 20 characters
	 * @return command processing error code
	 */
	NK_C_API int NK_unlock_encrypted_volume(const char* user_pin);

	/**
	 * Locks encrypted volume
	 * @return command processing error code
	 */
	NK_C_API int NK_lock_encrypted_volume();

	/**
	 * Unlock hidden volume and lock encrypted volume.
	 * Requires encrypted volume to be unlocked.
	 * Storage only
	 * @param hidden_volume_password 20 characters
	 * @return command processing error code
	 */
	NK_C_API int NK_unlock_hidden_volume(const char* hidden_volume_password);

	/**
	 * Locks hidden volume
	 * @return command processing error code
	 */
	NK_C_API int NK_lock_hidden_volume();

	/**
	 * Create hidden volume.
	 * Requires encrypted volume to be unlocked.
	 * Storage only
	 * @param slot_nr slot number in range 0-3
	 * @param start_percent volume begin expressed in percent of total available storage, int in range 0-99
	 * @param end_percent volume end expressed in percent of total available storage, int in range 1-100
	 * @param hidden_volume_password 20 characters
	 * @return command processing error code
	 */
	NK_C_API int NK_create_hidden_volume(uint8_t slot_nr, uint8_t start_percent, uint8_t end_percent,
		const char *hidden_volume_password);

	/**
	 * Make unencrypted volume read-only.
	 * Device hides unencrypted volume for a second therefore make sure
	 * buffers are flushed before running.
	 * Does nothing if firmware version is not matched
	 * Firmware range: Storage v0.50, v0.48 and below
	 * Storage only
	 * @param user_pin 20 characters User PIN
	 * @return command processing error code
	 */
	NK_C_API int NK_set_unencrypted_read_only(const char *user_pin);

	/**
	 * Make unencrypted volume read-write.
	 * Device hides unencrypted volume for a second therefore make sure
	 * buffers are flushed before running.
	 * Does nothing if firmware version is not matched
	 * Firmware range: Storage v0.50, v0.48 and below
	 * Storage only
	 * @param user_pin 20 characters User PIN
	 * @return command processing error code
	 */
	NK_C_API int NK_set_unencrypted_read_write(const char *user_pin);

	/**
	 * Make unencrypted volume read-only.
	 * Device hides unencrypted volume for a second therefore make sure
	 * buffers are flushed before running.
	 * Does nothing if firmware version is not matched
	 * Firmware range: Storage v0.49, v0.51+
	 * Storage only
	 * @param admin_pin 20 characters Admin PIN
	 * @return command processing error code
	 */
	NK_C_API int NK_set_unencrypted_read_only_admin(const char* admin_pin);

	/**
	 * Make unencrypted volume read-write.
	 * Device hides unencrypted volume for a second therefore make sure
	 * buffers are flushed before running.
	 * Does nothing if firmware version is not matched
	 * Firmware range: Storage v0.49, v0.51+
	 * Storage only
	 * @param admin_pin 20 characters Admin PIN
	 * @return command processing error code
	 */
	NK_C_API int NK_set_unencrypted_read_write_admin(const char* admin_pin);

	/**
	 * Make encrypted volume read-only.
	 * Device hides encrypted volume for a second therefore make sure
	 * buffers are flushed before running.
	 * Firmware range: v0.49 only, future (see firmware release notes)
	 * Storage only
	 * @param admin_pin 20 characters
	 * @return command processing error code
	 */
	NK_C_API int NK_set_encrypted_read_only(const char* admin_pin);

	/**
	 * Make encrypted volume read-write.
	 * Device hides encrypted volume for a second therefore make sure
	 * buffers are flushed before running.
	 * Firmware range: v0.49 only, future (see firmware release notes)
	 * Storage only
	 * @param admin_pin 20 characters
	 * @return command processing error code
	 */
	NK_C_API int NK_set_encrypted_read_write(const char* admin_pin);

	/**
	 * Exports device's firmware to unencrypted volume.
	 * Storage only
	 * @param admin_pin 20 characters
	 * @return command processing error code
	 */
	NK_C_API int NK_export_firmware(const char* admin_pin);

	/**
	 * Clear new SD card notification. It is set after factory reset.
	 * Storage only
	 * @param admin_pin 20 characters
	 * @return command processing error code
	 */
	NK_C_API int NK_clear_new_sd_card_warning(const char* admin_pin);

	/**
	 * Fill SD card with random data.
	 * Should be done on first stick initialization after creating keys.
	 * Storage only
	 * @param admin_pin 20 characters
	 * @return command processing error code
	 */
	NK_C_API int NK_fill_SD_card_with_random_data(const char* admin_pin);

	/**
	 * Change update password.
	 * Update password is used for entering update mode, where firmware
	 * could be uploaded using dfu-programmer or other means.
	 * Storage only
	 * @param current_update_password 20 characters
	 * @param new_update_password 20 characters
	 * @return command processing error code
	 */
	NK_C_API int NK_change_update_password(const char* current_update_password,
		const char* new_update_password);

	/**
	 * Enter update mode. Needs update password.
	 * When device is in update mode it no longer accepts any HID commands until
	 * firmware is launched (regardless of being updated or not).
	 * Smartcard (through CCID interface) and its all volumes are not visible as well.
	 * Its VID and PID are changed to factory-default (03eb:2ff1 Atmel Corp.)
	 * to be detected by flashing software. Result of this command can be reversed
	 * by using 'launch' command.
	 * For dfu-programmer it would be: 'dfu-programmer at32uc3a3256s launch'.
	 * Storage only
	 * @param update_password 20 characters
	 * @return command processing error code
	 */
	NK_C_API int NK_enable_firmware_update(const char* update_password);

	/**
	 * Get Storage stick status as string.
	 * Storage only
	 * @return string with devices attributes
	 */
	NK_C_API char* NK_get_status_storage_as_string();

	/**
	 * Get the Storage stick status and return the command processing
	 * error code.  If the code is zero, i. e. the command was successful,
	 * the storage status is written to the output pointer's target.
	 * The output pointer must not be null.
	 *
	 * @param out the output pointer for the storage status
	 * @return command processing error code
	 */
	NK_C_API int NK_get_status_storage(struct NK_storage_status* out);

	/**
	 * Get SD card usage attributes. Usable during hidden volumes creation.
	 * If the command was successful (return value 0), the usage data is
	 * written to the output pointer’s target.  The output pointer must
	 * not be null.
	 * Storage only
	 * @param out the output pointer for the usage data
	 * @return command processing error code
	 */
	NK_C_API int NK_get_SD_usage_data(struct NK_SD_usage_data* out);

	/**
	 * Get SD card usage attributes as string.
	 * Usable during hidden volumes creation.
	 * Storage only
	 * @return string with SD card usage attributes
	 */
	NK_C_API char* NK_get_SD_usage_data_as_string();

	/**
	 * Get progress value of current long operation.
	 * Storage only
	 * @return int in range 0-100 or -1 if device is not busy or -2 if an
	 *         error occured
	 */
	NK_C_API int NK_get_progress_bar_value();

/**
 * Returns a list of connected devices' id's, delimited by ';' character. Empty string is returned on no device found.
 * Each ID could consist of:
 * 1. SC_id:SD_id_p_path (about 40 bytes)
 * 2. path (about 10 bytes)
 * where 'path' is USB path (bus:num), 'SC_id' is smartcard ID, 'SD_id' is storage card ID and
 * '_p_' and ':' are field delimiters.
 * Case 2 (USB path only) is used, when the device cannot be asked about its status data (e.g. during a long operation,
 * like clearing SD card.
 * Internally connects to all available devices and creates a map between ids and connection objects.
 * Side effects: changes active device to last detected Storage device.
 * Storage only
 * @example Example of returned data: '00005d19:dacc2cb4_p_0001:0010:02;000037c7:4cf12445_p_0001:000f:02;0001:000c:02'
 * @return string delimited id's of connected devices
 */
	NK_C_API char* NK_list_devices_by_cpuID();

	/**
	 * Returns a linked list of all connected devices, or null if no devices
	 * are connected or an error occured.  The linked list must be freed by
	 * calling NK_free_device_info.
	 * @return a linked list of all connected devices
	 */
	NK_C_API struct NK_device_info* NK_list_devices();

	/**
	 * Free a linked list returned by NK_list_devices.
	 * @param the linked list to free or null
	 */
	NK_C_API void NK_free_device_info(struct NK_device_info* device_info);

/**
 * Connects to the device with given ID. ID's list could be created with NK_list_devices_by_cpuID.
 * Requires calling to NK_list_devices_by_cpuID first. Connecting to arbitrary ID/USB path is not handled.
 * On connection requests status from device and disconnects it / removes from map on connection failure.
 * Storage only
 * @param id Target device ID (example: '00005d19:dacc2cb4_p_0001:0010:02')
 * @return 1 on successful connection, 0 otherwise
 */
	NK_C_API int NK_connect_with_ID(const char* id);

	/**
	 * Connects to a device with the given path.  The path is a USB device
	 * path as returned by hidapi.
	 * @param path the device path
	 * @return 1 on successful connection, 0 otherwise
	 */
        NK_C_API int NK_connect_with_path(const char* path);

	/**
	 * Blink red and green LED alternatively and infinitely (until device is reconnected).
	 * @return command processing error code
	 */
	NK_C_API int NK_wink();


	/**
	 * Enable update mode on Nitrokey Pro.
	 * Supported from v0.11.
	 * @param update_password 20 bytes update password
   * @return command processing error code
	 */
	NK_C_API int NK_enable_firmware_update_pro(const char* update_password);

  /**
   * Change update-mode password on Nitrokey Pro.
   * Supported from v0.11.
   * @param current_firmware_password 20 bytes update password
   * @param new_firmware_password 20 bytes update password
   * @return command processing error code
   */
  NK_C_API int NK_change_firmware_password_pro(const char *current_firmware_password, const char *new_firmware_password);


// as in ReadSlot::ResponsePayload
struct ReadSlot_t {
  uint8_t slot_name[15];
  uint8_t _slot_config;
  uint8_t slot_token_id[13];
  uint64_t slot_counter;
};


NK_C_API int NK_read_HOTP_slot(const uint8_t slot_num, struct ReadSlot_t* out);

#ifdef __cplusplus
}
#endif
extern uint8_t NK_last_command_status;

#endif //LIBNITROKEY_NK_C_API_H