YUBISET

A collection of scripts to make OpenPGP key generation and YubiKey manipulation easy.

What does it do?

• create GPG keys on Yubikey
• Set user information for Yubikey (name, lang, etc)
• Set User and Admin PIN for Yubikey

Table of Contents

• YUBISET
• What does it do?
• Supported Environments
• Supported Yubikeys
• Prerequisites
  • Linux
  • Mac
• Usage
  • MacOS/Unix
    • Start here: Key generation & Yubikey setup (all in one script)
      • Move PGP keys to Yubikey only
      • Reset Yubikey's OpenPGP module
      • Find Yubikey Slot
• For Developers
  • Clone with git
  • Flush issues
  • README.md Table of Contents

Supported Environments

• Unix (Bash)

Supported Yubikeys

• Yubikey 5 (firmware >5.2)

Prerequisites

The only thing you'll need is a working gpg installation:

Linux

Use the GnuPG package provided with your distribution or follow the instructions on https://gnupg.org.

Mac

brew install gnupg pinentry-mac ykman

Usage

MacOS-Unix

Start here: Key generation & Yubikey setup (all in one script)

cd unix/bash
sh yubiset.sh

The following scripts may be used standalone but are also called from the yubiset main script:

Move PGP keys to Yubikey only

cd unix/bash
sh setupyubi.sh "Given Name Surname" "[email protected]" "PGP key id" "passphrase"

Due to security reasons the passphrase may also be omitted. In this case the user will be prompted to enter it.

Reset Yubikey's OpenPGP module

BE AWARE: Only tested with Yubikey 4 NEO and Yubikey 5

cd unix/bash
sh resetyubi.sh

Find Yubikey Slot

cd unix/bash
sh findyubi.sh

Key Branding

It is possible to "brand" your generated keys, i. e. give the user name and the comment a custom touch e. g. for your company. This can be controlled by editing the file unix/bash/lib/branding.sh.

The default will produce a key like this:

sec   rsa4096/0x94AF5E3D1575AC6A 2019-07-01 [C] [expires: 2020-06-30]
      Key fingerprint = 3B90 7B16 76E6 9F6F 59D1  D103 94AF 5E3D 1575 AC6A
uid                   [ultimate] Max Muster <[email protected]>

However a branding.sh like this:

declare -r branded_user_name="${user_name} (itemis AG)"
declare -r branded_user_comment="Vocational key of itemis AG's Max Muster"

will produce the following key:

sec   rsa4096/0x94AF5E3D1575AC6A 2019-07-01 [C] [expires: 2020-06-30]
      Key fingerprint = 3B90 7B16 76E6 9F6F 59D1  D103 94AF 5E3D 1575 AC6A
uid                   [ultimate] Max Muster (itemis AG) (Vocational OpenPGP key of itemis AG's Max Muster) <[email protected]>

Be aware: GPG does not support arbitrary charaters in key comments. Especially parantheses '(' and ')' will cause problems. Don't use them.

Flush issues

Be aware that on some file systems / operating systems generating (log) files may take some time and in order for the gpg-agent and scdaemon to recognize changes it may also take some time, so retrying probes etc. is advised in order to make sure the script does not unnecessarily fail.