use the nth YubiKey found.-1
change the first configuration. This is the default and is normally used for true OTP generation. In this configuration, the option flag -oappend-cr is set by default.-2
change the second configuration. This is for YubiKey II only and is then normally used for static key generation. In this configuration, the option flags -oappend-cr, -ostatic-ticket, -ostrong-pw1, -ostrong-pw2 and -oman-update are set by default.-z
delete configuration in selected slot-sfile
save configuration to file instead of key. (if file is -, send to stdout)-ifile
read configuration from file. (if file is -, read from stdin) Configuration import is only valid for the ycfg format.-fformat
format to be used with -s and -i. Valid options are ycfg and legacy.-a[xxx]
the AES secret key as a 32 (or 40 for OATH-HOTP/HMAC CHAL-RESP) char hex value (not modhex) (none to prompt for key on stdin) If -a is not used a random key will be generated.-c[xxx]
A 12 char hex value (not modhex) to use as access code for programming. NOTE: this does NOT SET the access code, that’s done with -oaccess=. If no argument is provided code is prompted for on stdin.-ooption
change configuration option. Possible option arguments are: fixed=fffffffffff-y
The modhex public identity of the YubiKey, 0-32 characters long (encoding up to 16 bytes). It’s possible to give the identity in hex as well, just prepend the value with ’h:’. The fixed part is emitted before the OTP when the button on the YubiKey is pressed. It can be used as an identifier for the user, for example.uid[=uuuuuu]
The uid part of the generated OTP, also called private identity, in hex. Must be 12 characters long. The uid is 6 bytes of static data that is included (encrypted) in every OTP, and is used to validate that an OTP was in fact encrypted with the AES key shared between the YubiKey and the validation service. It cannot be used to identify the YubiKey as it is only readable to those that know the AES key. If no argument is provided the uid is prompted for on stdin.access[=fffffffffff]
New hex access code to set. Must be 12 characters long. If an access code is set, it will be required for subsequent reprogramming of the YubiKey. If no argument is provided code is prompted for on stdin.oath-imf=xxx
Set OATH Initial Moving Factor. This is the initial counter value for the YubiKey. This should be a value between 0 and 1048560, evenly dividable by 16.ticket-flag
Set/clear ticket flag, see the section Ticket flagsconfiguration-flag
Set/clear ticket flag, see the section Configuration flags
always commit without prompting-d
dry-run, run without writing a YubiKey-v
Be more verbose-h
Program NFC NDEF URI-t text
Program NFC NDEF text
set device configuration for the YubiKey. It is parsed in the form mode:cr_timeout:autoeject_timeout where mode is: 0Removing OTP mode also disable communication between ykpersonalize and the YubiKey, further mode changes will have to be done with ykneomgr (for CCID mode) or u2f-host (for U2F mode)
OTP device only.1
CCID device only.2
OTP/CCID composite device.3
U2F device only.4
OTP/U2F composite device.5
U2F/CCID composite device.6
OTP/U2F/CCID composite device. Add 80 to set MODE_FLAG_EJECT, for example: 81 cr_timeout is the timeout in seconds for the YubiKey to wait on button press for challenge response (default is 15) autoeject_timeout is the timeout in seconds before the card is automatically ejected in mode 81
set the scanmap to be used with the YubiKey. It must be 45 unique bytes as 90 characters. Leave argument empty to reset to the YubiKey’s default. The scanmap must be sent in the order:
Set the deviceinfo to use with this YubiKey.
Update existing configuration, rather than overwriting. Only possible if the slot is configured as updatable.-x
Swap configuration slot 1 and 2 inside the YubiKey. Only possible if both slots are configured as updatable.
Send a tab character as the first character. This is usually used to move to the next input field.append-tab1
Send a tab character between the fixed part and the one-time password part. This is useful if you have the fixed portion equal to the user name and two input fields that you navigate between using tab.append-tab2
Send a tab character as the last character.append-delay1
add a half-second delay before sending the one-time password part. This option is only valid for firmware 1.x and 2.x.append-delay2
a half-second delay after sending the one-time password part. This option is only valid for firmware 1.x and 2.x.append-cr
a carriage return after sending the one-time password part.
When written to configuration 1, block later updates to configuration 2. When written to configuration 2, prevent configuration 1 from having the lock bit set.
Set OATH-HOTP mode rather than YubiKey mode. In this mode, the token functions according to the OATH-HOTP standard.
Set challenge-response mode.
Send a reference string of all 16 modhex characters before the fixed part. When combined with -ostrong-pw2 this sends a ! before the rest of the string.pacing-10ms
Add a 10ms delay between key presses.pacing-20ms
Add a 20ms delay between key presses.static-ticket
Output a fixed string rather than a one-time password. The password is still based on the AES key and should be hard to guess and impossible to remember.
Send the one-time password rather than the fixed part first.allow-hidtrig
Allow trigger through HID/keyboard by pressing caps-, num or scroll-lock twice. Not recommended for security reasons.
Limit the length of the static string to max 16 digits. This flag only makes sense with the -ostatic-ticket option. When -oshort-ticket is used without -ostatic-ticket it will program the YubiKey in "scan-code mode", in this mode the key sends the contents of fixed, uid and key as raw keyboard scancodes. For example, by using the fixed string h:8b080f0f122c9a12150f079e in this mode it will send Hello World! on a qwerty keyboard. This mode sends raw scan codes, so output will differ between keyboard layouts.strong-pw1
Upper-case the two first letters of the output string. This is for compatibility with legacy systems that enforce both uppercase and lowercase characters in a password and does not add any security.strong-pw2
Replace the first eight characters of the modhex alphabet with the numbers 0 to 7. Like -ostrong-pw1, this is intended to support legacy systems.man-update
Enable user-initiated update of the static password. Only makes sense with the -ostatic-ticket option. This is only valid for firmware 2.x.
When set, generate an 8-digit HOTP rather than a 6-digit one.oath-fixed-modhex1
When set, the first byte of the fixed part is sent as modhex.oath-fixed-modhex2
When set, the first two bytes of the fixed part is sent as modhex.oath-fixed-modhex
When set, the fixed part is sent as modhex.oath-id=m:OOTTUUUUUUUU
Configure OATH token id with a provided value. See description of this option under the 2.2 section for details, but note that a YubiKey 2.1 key can’t report its serial number and thus a token identifier value must be specified.
Yubico OTP challenge-response mode.chal-hmac
Generate HMAC-SHA1 challenge responses.hmac-lt64
Calculate HMAC on less than 64 bytes input. Whatever is in the last byte of the challenge is used as end of input marker (backtracking from end of payload).chal-btn-trig
The YubiKey will wait for the user to press the key (within 15 seconds) before answering the challenge.serial-btn-visible
The YubiKey will emit its serial number if the button is pressed during power-up. This option is only valid for the 2.x firmware line.serial-usb-visible
The YubiKey will indicate its serial number in the USB iSerial field. This option is not available in the 3.0 and 3.1 firmwares.serial-api-visible
The YubiKey will allow its serial number to be read using an API call.oath-id[=m:OOTTUUUUUUUU]
Configure OATH token id with a provided value, or if used without a value use the standard YubiKey token identifier.The standard OATH token id for a Yubico YubiKey is (modhex) OO=ub, TT=he, (decimal) UUUUUUUU=serial number. The reason for the decimal serial number is to make it easy for humans to correlate the serial number on the back of the YubiKey to an entry in a list of associated tokens for example. Other encodings can be accomplished using the appropriate oath-fixed-modhex options. Note that the YubiKey must be programmed to allow reading its serial number, otherwise automatic token id creation is not possible. See section "5.3.4 - OATH-HOTP Token Identifier" of the YubiKey manual http://yubico.com/files/YubiKey_manual-2.0.pdf for further details.
Send scancodes for numeric keypad keypresses when sending digits - helps with some keyboard layouts. This option is only valid for the 2.x firmware line.fast-trig
Faster triggering when only configuration 1 is available. This option is always in effect on firmware versions 3.0 and above.allow-update
Allow updating (or swapping) of certain parameters in a configuration at a later time.dormant
Hides/unhides a configuration stored in a YubiKey.
Inverts the behaviour of the led on the YubiKey.
tr "[0123456789abcdef]" "[cbdefghijklnrtuv]"
tr "[cbdefghijklnrtuv]" "[0123456789abcdef]"
ykpersonalize -1 -ouid=h:`dd if=/dev/urandom bs=1 count=6 status=none | hexdump -e '/1 "%02x"'` -ofixed=h:ff`dd if=/dev/urandom bs=1 count=5 status=none | hexdump -e '/1 "%02x"'`