Yubikey NEO/4 GPG Setup

99-yubikey-neo.rules

SUBSYSTEMS=="usb", ATTRS{idVendor}=="1050", ATTRS{idProduct}=="0115", OWNER="USERNAME"

scp.sh

#!/bin/bash

#Connect to an SSH server using the gpg agent for authentication
SSH_AUTH_SOCK=~/.gnupg/S.gpg-agent.ssh scp ${@:2}

ssh.sh

#!/bin/bash

#Connect to an SSH server using the gpg agent for authentication
SSH_AUTH_SOCK=~/.gnupg/S.gpg-agent.ssh ssh ${@:2}

yubikey-setup.sh

#!/bin/bash
# Script to setup Yubikey PGP for SSH authentication on Linux
# MacOS works similarly, though gpgtools must be installed from https://gpgtools.org/ and udev rules are not required
# 
# See https://www.esev.com/blog/post/2015-01-pgp-ssh-key-on-yubikey-neo/ for more details.
# If you're using gnome, you also need to follow the instructions here: 
# http://blog.josefsson.org/2015/01/02/openpgp-smartcards-and-gnome/
#
# To convert GPG public key to SSH public key for ~/.ssh/authorized_keys use `gpgkey2ssh FINGERPRINT`

# Check user id is not root
if [ "$(id -u)" == "0" ]; then
   echo "This script should be run as a user" 1>&2
   exit 1
fi

USER=$(whoami)

# Copy and reload udev rules
sudo cp 99-yubikey-neo.rules /etc/udev/rules.d
sudo sed -i '.bkp' "s/USERNAME/$USER/g" /etc/udev/rules.d/99-yubikey-neo.rules
sudo udevadm control --reload-rules

# Force GPG to fetch keys from the device
# This will try to fetch the keys from the provided public key URL
gpg --list-keys

# Enable gpg-agent as an SSH authentication provider
echo "use-agent" >> ~/.gnupg/gpg.conf
echo "enable-ssh-support" >> ~/.gnupg/gpg-agent.conf