MAN page from Fedora 16 ykpers-1.6.0-2.fc16.i686.rpm


Section: Misc. Reference Manual Pages (1)
Updated: August 2009


ykpersonalize - personalize Yubikey OTP tokens 


ykpersonalize[-1 | -2] [-sfile] [-ifile] [-axxx] [-cxxx] [-ooption] [-v] [-h] 


Set the AES key, user ID and other settings in a Yubikey. For the completeexplanation of the meaning of all parameters, see the referencemanual: laURL: L raYubikey manual

change the first configuration. This is the default and isnormally used for true OTP generation. In this configuration,TKTFLAG_APPEND_CR is set by default.
change the second configuration. This is for Yubikey II only and isthen normally used for static key generation. In this configuration,TKTFLAG_APPEND_CR, CFGFLAG_STATIC_TICKET, CFGFLAG_STRONG_PW1,CFGFLAG_STRONG_PW2 and CFGFLAG_MAN_UPDATE are set by default.
save configuration to file instead of key.(if file is -, send to stdout)
read configuration from file.(if file is -, read from stdin)
A 32 char (40 for OATH-HOTP and HMAC challenge-response) hex value (not modhex) of a fixed AES key to use.
A 12 char hex value (not modhex) to use as access code forprogramming.NOTE: this does NOT SET the access code, that's done with -oaccess=.
change configuration option. Possible option arguments are
Salt to be used when deriving key from a password.If none is given, a unique random one will be generated.
The modhex public identity of the Yubikey, 0-16 characters long.It's possible to give the identity in hex as well, just prepend thevalue with `h:'. The fixed part is emitted before the OTP when thebutton on the Yubikey is pressed. It can be used as an identifier forthe user, for example.
The uid part of the generated OTP, 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 encryptedwith the AES key shared between the Yubikey and the validation service. It cannotbe used to identify the Yubikey as it is only readable to those that knowthe AES key.
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.
Set/clear ticket flag, see the section `Ticket flags'
Set/clear ticket flag, see the section `Configuration flags'
always commit without prompting
Be more verbose

Ticket flags

Send a tab character as the first character. This is usually used to moveto the next input field.
Send a tab character between the fixed part and the one-time passwordpart. This is useful if you have the fixed portion equal to the username and two input fields that you navigate between using tab.
Send a tab character as the last character.
Add a half-second delay before sending the one-time password part.
Add a half-second delay after sending the one-time password part.
Send a carriage return after sending the one-time password part.
Yubikey 2.0 firmware and above
When written to configuration 1, block later updates to configuration2. When written to configuration 2, prevent configuration 1 fromhaving the lock bit set.
Yubikey 2.1 firmware and above
Set OATH-HOTP mode rather than Yubikey mode. In this mode, the tokenfunctions according to the OATH-HOTP standard.
Yubikey 2.2 firmware and above
Set challenge-response mode.

Configuration flags

[-]send-refSend a reference string of all 16 modhex characters before the fixedpart. This can not be combined with the strong-pw2 flag.
Add a 10ms delay between key presses.
Add a 20ms delay between key presses.
Output a fixed string rather than a one-time password. The passwordis still based on the AES key and should be hard to guess andimpossible to remember.
Yubikey 1.x firmware only
Send the one-time password rather than the fixed part first.
Allow trigger through HID/keyboard by pressing caps-, num orscroll-lock twice. Not recommended for security reasons.
Yubikey 2.0 firmware and above
Limit the length of the static string to max 16 digits. This flagonly makes sense with the -ostatic-ticket option.
Upper-case the two first letters of the output string. This is forcompatibility with legacy systems that enforce both uppercase andlowercase characters in a password and does not add any security.
Replace the first eight characters of the modhex alphabet with thenumbers 0 to 7. Like strong-pw1, this is intended to supportlegacy systems.
Enable user-initiated update of the static password. Only makes sensewith the -ostatic-ticket option.
Yubikey 2.1 firmware and above
When set, generate an 8-digit HOTP rather than a 6-digit one.
When set, the first byte of the fixed part is sent as modhex.
When set, the first two bytes of the fixed part is sent as modhex.
When set, the fixed part is sent as modhex.
Yubikey 2.2 firmware and above
Yubico OTP challenge-response mode.
Generate HMAC-SHA1 challenge responses.
Calculate HMAC on less than 64 bytes input. Whatever is in the last byteof the challenge is used as end of input marker (backtracking from end of payload).
The Yubikey will wait for the user to press the key (within 15 seconds) beforeanswering the challenge.



When using OATH-HOTP mode, a HMAC key of 160 bits (20 bytes, 40 chars of hex)can be supplied with -a.

The token identifier can be set with the -ofixed= option.See section "5.3.4 - OATH-HOTP Token Identifier" of the laURL: L raYubikey manualfor details, but in short the token identifier is 2 bytes manufacturer prefix,2 bytes token type and then 8 bytes manufacturer unique ID.


Challenge-response Mode

In CHAL-RESP mode, the token will NOT generate any keypresses when the buttonis pressed (although it is perfectly possible to have one slot with a keypress-generatingconfiguration, and the other in challenge-response mode). Instead, a program capable ofsending USB HID feature reports to the token must be used to send it a challenge, andread the response.



Modhex is a way of writing hex digits where the lqdigitsrq arechosen for being in the same place on most keyboard layouts.
To convert from hex to modhex, you can use
tr "[0123456789abcdef]" "[cbdefghijklnrtuv]"
To convert the other way, use
tr "[cbdefghijklnrtuv]" "[0123456789abcdef]"



Report ykpersonalize bugs in laURL: L rathe issue tracker 


The laURL: L raykpersonalize home page

Yubikeys can be obtained from laURL: L raYubico



Ticket flags
Configuration flags
Challenge-response Mode

This document was created byman2html,using the manual pages.