/*
* 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 .
*
* SPDX-License-Identifier: LGPL-3.0
*/
#ifndef LIBNITROKEY_NK_C_API_H
#define LIBNITROKEY_NK_C_API_H
#include
#include
#include "deprecated.h"
#ifdef _MSC_VER
#define NK_C_API __declspec(dllexport)
#else
#define NK_C_API
#endif
#ifdef __cplusplus
extern "C" {
#endif
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
};
/**
* 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;
};
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
* @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.
* @return command processing error code
*/
NK_C_API char * NK_status();
/**
* 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();
/**
* 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);
/**
* Get currently set config - status of function Numlock/Capslock/Scrollock OTP sending and is enabled PIN protected OTP
* @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();
//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}
* > {@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
* @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();
/**
* 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 int 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 int 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 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
*/
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();
/**
* 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();
#ifdef __cplusplus
}
#endif
#endif //LIBNITROKEY_NK_C_API_H