Purpose

Configure YubiKey Nano to not send key press automatically:

1. Assuming your YubiKey Nano is already actively sitting in a USB slot, ensure you have ‘ykpers’ RPM, to get the ykinfo tool:

   $> rpm -qf ``which ykinfo``
   ykpers-1.18.0-2.fc26.x86_64

2. Run it to get all the information like active slots:

   $> ykinfo -a
   serial: 2816141
   serial_hex: 2af88d
   serial_modhex: dlvjjt
   version: 2.4.3
   touch_level: 2817
   programming_sequence: 1
   slot1_status: 1
   slot2_status: 0
   vendor_id: 1050
   product_id: 10

3. The tool to configure YubiKey Nano to not automatically send the key is ykpersonalize.

(NB: In my case above, the slot-1 was active, that’s why I chose “-1” below.)

4. Do a dry run of the magic incantation:

   $> ykpersonalize -u -1 -o-append-cr -d
   Firmware version 2.4.3 Touch level 2817 Program sequence 1
   
   Configuration data to be updated in key configuration 1:
   
   fixed: m:
   uid: 000000000000
   key: h:00000000000000000000000000000000
   acc_code: h:000000000000
   ticket_flags:
   config_flags:
   extended_flags: ALLOW_UPDATE
   
   Commit? (y/n) [n]: y
   Not writing anything to key due to dry_run requested.

5. Since the above works, now re-run, this time, without the dry-run option (-d):

   $> ykpersonalize -u -1 -o-append-cr Firmware version 2.4.3 Touch
   level 2817 Program sequence 1
   
   Configuration data to be updated in key configuration 1:
   
   fixed: m: uid: 000000000000 key: h:00000000000000000000000000000000
   acc_code: h:000000000000 ticket_flags: config_flags: extended_flags:
   ALLOW_UPDATE
   
   $> echo $? 0

Test it by tapping the YubiKey Nano, now you shouldn’t see an automatic key press.