nitrocli man page

nitrocli — access Nitrokey devices

Synopsis

nitrocli [-m|--model pro|storage] [-v|--verbose] [-V|--version] command [arguments]

Description

nitrocli provides access to Nitrokey devices. It supports the Nitrokey Pro and the Nitrokey Storage. It can be used to access the encrypted volume, the one-time password generator, and the password safe.

Options

-m, --model pro|storage

Restrict connections to the given device model. If this option is not set, nitrocli will connect to any connected Nitrokey Pro or Nitrokey Storage device.

-v, --verbose

Enable additional logging and control its verbosity. Logging enabled through this option will appear on the standard error stream. This option can be supplied multiple times. A single occurrence will show additional warnings. Commands sent to the device will be shown when supplied three times and full device communication is available with four occurrences. Supplying this option five times enables the highest verbosity.

-V, --version

Print the nitrocli version and exit.

Commands

General

nitrocli status

Print the status of the connected Nitrokey device, including the stick serial number, the firmware version, and the PIN retry count.

nitrocli lock

Lock the Nitrokey. This command locks the password safe (see the Password safe section). On the Nitrokey Storage, it will also close any active encrypted or hidden volumes (see the Storage section).

nitrocli reset

Perform a factory reset on the Nitrokey. This command performs a factory reset on the OpenPGP smart card, clears the flash storage and builds a new AES key. The user PIN is reset to 123456, the admin PIN to 12345678.

This command requires the admin PIN. To avoid accidental calls of this command, the user has to enter the PIN even if it has been cached.

Storage

The Nitrokey Storage comes with a storage area. This area is comprised of an unencrypted region and an encrypted one of fixed sizes, each made available to the user in the form of block devices. The encrypted region can optionally further be overlayed with up to four hidden volumes. Because of this overlay (which is required to achieve plausible deniability of the existence of hidden volumes), the burden of ensuring that data on the encrypted volume does not overlap with data on one of the hidden volumes is on the user.

nitrocli storage open

Open the encrypted volume on the Nitrokey Storage. The user PIN that is required to open the volume is queried using pinentry(1) and cached by gpg-agent(1).

nitrocli storage close

Close the encrypted volume on the Nitrokey Storage.

nitrocli storage status

Print the status of the connected Nitrokey Storage device's storage. The printed information includes the SD card serial number, the encryption status, and the status of the volumes.

nitrocli storage hidden create slot start end

Create a new hidden volume inside the encrypted volume. slot must indicate one of the four available slots. start and end represent, respectively, the start and end position of the hidden volume inside the encrypted volume, as a percentage of the encrypted volume's size. This command requires a password which is later used to look up the hidden volume to open. Unlike a PIN, this password is not cached by gpg-agent(1).

nitrocli storage hidden open

Open a hidden volume. The volume to open is determined based on the password entered, which must have a minimum of six characters. Only one hidden volume can be active at any point in time and previously opened volumes will be automatically closed. Similarly, the encrypted volume will be closed if it was open.

nitrocli storage hidden close

Close a hidden volume.

One-time passwords

The Nitrokey Pro and the Nitrokey Storage support the generation of one-time passwords using the HOTP algorithm according to RFC 4226 or the TOTP algorithm according to RFC 6238. The required data – a name and the secret – is stored in slots. Currently, the Nitrokey devices provide three HOTP slots and 15 TOTP slots. The slots are numbered per algorithm starting at zero.

The TOTP algorithm is a modified version of the HOTP algorithm that also uses the current time. Therefore, the Nitrokey clock must be synchronized with the clock of the application that requests the one-time password.

nitrocli otp get slot [-a|--algorithm algorithm] [-t|--time time]

Generate a one-time password. slot is the number of the slot to generate the password from. algorithm is the OTP algorithm to use. Possible values are hotp for the HOTP algorithm according to RFC 4226 and totp for the TOTP algorithm according to RFC 6238 (default). Per default, this commands sets the Nitrokey's time to the system time if the TOTP algorithm is selected. If --time is set, it is set to time instead, which must be a Unix timestamp (i.e., the number of seconds since 1970-01-01 00:00:00 UTC). This command might require the user PIN (see the Configuration section).

nitrocli otp set slot name secret [-a|--algorithm algorithm] [-d|--digits digits] [-c|--counter counter] [-t|--time-window time-window] [-f|--format ascii|base32|hex]

Configure a one-time password slot. slot is the number of the slot to configure. name is the name of the slot (may not be empty). secret is the secret value to store in that slot.

The --format option specifies the format of the secret. If it is set to ascii, each character of the given secret is interpreted as the ASCII code of one byte. If it is set to base32, the secret is interpreted as a base32 string according to RFC 4648. If it is set to hex, every two characters are interpreted as the hexadecimal value of one byte. The default value is hex.

algorithm is the OTP algorithm to use. Possible values are hotp for the HOTP algorithm according to RFC 4226 and totp for the TOTP algorithm according to RFC 6238 (default). digits is the number of digits the one-time password should have. Allowed values are 6 and 8 (default: 6). counter is the initial counter if the HOTP algorithm is used (default: 0). time window is the time window used with TOTP in seconds (default: 30).

nitrocli otp clear slot [-a|--algorithm algorithm]

Delete the name and the secret stored in a one-time password slot. slot is the number of the slot to clear. algorithm is the OTP algorithm to use. Possible values are hotp for the HOTP algorithm according to RFC 4226 and totp for the TOTP algorithm according to RFC 6238 (default).

nitrocli otp status [-a|--all]

List all OTP slots. If --all is not set, empty slots are ignored.

Configuration

Nitrokey devices have four configuration settings:  the numlock, capslock and scrollock keys can be mapped to an HOTP slot, and OTP generation can be set to require the user PIN.

nitrocli config get

Print the current configuration.

nitrocli config set [[-n|--numlock slot] | [-N|--no-numlock]] [[-c|--capslock slot] | [-C|--no-capslock]] [[-s|--scrollock slot] | [-S|--no-scrollock]] [[-o|--otp-pin] | [-O|--no-otp-pin]]

Update the Nitrokey configuration. This command requires the admin PIN.

With the --numlock, --capslock and --scrollock options, the respective bindings can be set. slot is the number of the HOTP slot to bind the key to. If --no-numlock, --no-capslock or --no-scrollock is set, the respective binding is disabled. The two corresponding options are mutually exclusive.

If --otp-pin is set, the user PIN will be required to generate one-time passwords using the otp get command. If --no-otp-pin is set, OTP generation can be performed without PIN. These two options are mutually exclusive.

Password safe

The Nitrokey Pro and the Nitrokey Storage provide a password safe (PWS) with 20 slots. In each of these slots you can store a name, a login, and a password. The PWS is not encrypted, but it is protected with the user PIN by the firmware. Once the PWS is unlocked by one of the commands listed below, it can be accessed without authentication. You can use the lock command to lock the password safe.

nitrocli pws get slot [-n|--name] [-l|--login] [-p|--password] [-q|--quiet]

Print the content of one PWS slot. slot is the number of the slot. Per default, this command prints the name, the login and the password (in that order). If one or more of the options --name, --login, and --password are set, only the selected fields are printed. The order of the fields never changes.

The fields are printed together with a label. Use the --quiet option to suppress the labels and to only output the values stored in the PWS slot.

nitrocli pws set slot name login password

Set the content of a PWS slot. slot is the number of the slot to write. name, login, and password represent the data to write to the slot.

nitrocli pws clear slot

Delete the data stored in a PWS slot. slot is the number of the slot clear.

nitrocli pws status [-a|--all]

List all PWS slots. If --all is not set, empty slots are ignored.

PINs

Nitrokey devices have two PINs: the user PIN and the admin PIN. The user PIN must have at least six, the admin PIN at least eight characters. The user PIN is required for commands such as otp get (depending on the configuration) and for all pws commands. The admin PIN is usually required to change the device configuration.

Each PIN has a retry counter that is decreased with every wrong PIN entry and reset if the PIN was entered correctly. The initial retry counter is three. If the retry counter for the user PIN is zero, you can use the pin unblock command to unblock and reset the user PIN. If the retry counter for the admin PIN is zero, you have to perform a factory reset using the reset command or gpg(1). Use the status command to check the retry counters.

nitrocli pin clear

Clear the PINs cached by the other commands. Note that cached PINs are associated with the device they belong to and the clear command will only clear the PIN for the currently used device, not all others.

nitrocli pin set type

Change a PIN. type is the type of the PIN that will be changed:  admin to change the admin PIN or user to change the user PIN. This command only works if the retry counter for the PIN type is at least one. (Use the status command to check the retry counters.)

nitrocli pin unblock

Unblock and reset the user PIN. This command requires the admin PIN. The admin PIN cannot be unblocked. This operation is equivalent to the unblock PIN option provided by gpg(1) (using the --change-pin option).

Environment

The program honors a set of environment variables that can be used to suppress interactive PIN entry through pinentry(1). The following variables are recognized:

NITROCLI_ADMIN_PIN

The admin PIN to use.

NITROCLI_USER_PIN

The user PIN to use.

NITROCLI_NEW_ADMIN_PIN

The new admin PIN to set. This variable is only used by the pin set command for the admin type.

NITROCLI_NEW_USER_PIN

The new user PIN to set. This variable is only used by the pin set command for the user type.

NITROCLI_PASSWORD

A password used by commands that require one (e.g., storage hidden open).

NITROCLI_NO_CACHE

If this variable is present in the environment, do not cache any inquired secrets using gpg-agent(1) but ask for them each time they are needed. Note that this variable does not cause any cached secrets to be cleared. If a secret is already in the cache it will be ignored, but left otherwise untouched. Use the pin clear command to clear secrets from the cache.

Examples

Storage

Create a hidden volume in the first available slot, starting at half the size of the encrypted volume (i.e., 50%) and stretching all the way to its end (100%):
   $ nitrocli storage hidden create 0 50 100

One-time passwords

Configure a one-time password slot with a hexadecimal secret representation:
   $ nitrocli otp set 0 test-rfc4226 3132333435363738393031323334353637383930 --algorithm hotp
   $ nitrocli otp set 1 test-foobar 666F6F626172 --algorithm hotp
   $ nitrocli otp set 0 test-rfc6238 3132333435363738393031323334353637383930 --algorithm totp --digits 8

Configure a one-time password slot with an ASCII secret representation:
   $ nitrocli otp set 0 test-rfc4226 12345678901234567890 --format ascii --algorithm hotp
   $ nitrocli otp set 1 test-foobar foobar --format ascii --algorithm hotp
   $ nitrocli otp set 0 test-rfc6238 12345678901234567890 --format ascii --algorithm totp --digits 8

Configure a one-time password slot with a base32 secret representation:
   $ nitrocli otp set 0 test-rfc4226 gezdgnbvgy3tqojqgezdgnbvgy3tqojq --format base32 --algorithm hotp
   $ nitrocli otp set 1 test-foobar mzxw6ytboi====== --format base32 --algorithm hotp
   $ nitrocli otp set 0 test-rfc6238 gezdgnbvgy3tqojqgezdgnbvgy3tqojq --format base32 --algorithm totp --digits 8

Generate a one-time password:
   $ nitrocli otp get 0 --algorithm hotp
   755224
   $ nitrocli otp get 0 --algorithm totp --time 1234567890
   89005924

Clear a one-time password slot:
   $ nitrocli otp clear 0 --algorithm hotp

Configuration

Query the configuration:
   $ nitrocli config get
   Config:
     numlock binding:          not set
     capslock binding:         not set
     scrollock binding:        not set
     require user PIN for OTP: true

Change the configuration:
   $ nitrocli config set --otp-pin

Password safe

Configure a PWS slot:
   $ nitrocli pws set 0 example.org john.doe passw0rd

Get the data from a slot:
   $ nitrocli pws get 0
   name:     example.org
   login:    john.doe
   password: passw0rd

Copy the password to the clipboard (requires xclip(1)).
   $ nitrocli pws get 0 --password --quiet | xclip -in

Query the PWS slots:
   $ nitrocli pws status
   slot name
   0 example.org

Info

2019-05-26