8.9 KiB
Install Arch Linux
This chapter describes how to install a minimal Arch Linux. You will find an appropriated page in the Arch Wiki en / de.
Basic stuff
The base package and some additional packages for the YubiKey and full disk encryption will be installed to the /mnt folder.
If you want to know more about the individual package, please take a look at the Arch package site.
pacstrap /mnt base yubikey-manager yubikey-personalization pcsc-tools libu2f-host acpid dbus grub-efi-x86_64 efibootmgr lvm2
Generate fstab
The following command will generate the fstab entries of the currently mounted partitions.
genfstab -U -p /mnt >> /mnt/etc/fstab
Check it out with cat /mnt/etc/fstab and verify it.
YubiKey Full Disk Encryption
Next step is to copy the yubikey-full-disk-encryption folder
to the /mnt folder because it will be installed later. The YubiKey challenge is stored in a file to make it
available inside the new system. More on that later. Replace [Your YubiKey password] with your YubiKey password.
cp -r yubikey-full-disk-encryption /mnt/home/
echo "export YKFDE_CHALLENGE=$(printf [Your YubiKey password] | sha256sum | awk '{print $1}')" > /mnt/home/challenge.txt
Copy /etc/ykde.conf to /mnt/home so you can use this file later in your new environment.
Mount run folder
When running grub-mkconfig you will see the error /run/lvm/lvmetad.socket: connect failed: No such file or directory.
That's why the host /run folder must be available inside the chroot environment. This is prepared with the following
lines and finished later on.
mkdir /mnt/hostrun/
mount --bind /run /mnt/hostrun
chroot
It's time to switch into your new system with arch-chroot /mnt and prepare some stuff. After successfully changed root to
the new system, execute the following lines to make the hosts lvm available here for grub-mkconfig.
mkdir /run/lvm
mount --bind /hostrun/lvm /run/lvm
Next step is to install the yubikey-full-disk-encryption helper scripts. If they are not already copied in your home folder, you can it download from the GitHub repository yubikey-full-disk-encryption.
cd /home/yubikey-full-disk-encryption
make install
Copy /home/ykde.conf to /etc/ykde.conf so you have your previous settings or configure the file as described
in chapter Prepare YubiKey. The YubiKey challenge will now be stored in the ykde.conf
file. The environment variable with the YubiKey challenge is loaded into the environment so it can be set
into the ykde.conf file with the command sed.
source /home/challenge.txt
sed -i "s/#YKFDE_CHALLENGE=/YKFDE_CHALLENGE=$YKFDE_CHALLENGE/g" /etc/ykde.conf
Check that the YubiKey challenge was successfully saved to /etc/ykde.conf with cat /etc/ykde.conf.
mkinitcpio
The next step is to prepare the mkinitcpio.conf to encrypt the partition at boot. Open the file with
vi /etc/mkinitcpio.conf and replace the HOOKS line with the following content.
Don't add
encrypthook, because we ues ykfde and respect the order !!!
HOOKS=(base udev autodetect consolefont modconf block keymap lvm2 filesystems fsck keyboard ykfde)
Additionally the ext4 module is needed. Add ext4 to the MODULES. It should look like this line:
MODULES=(ext4)
GRUB
The next part is a bit tricky, because you have to figure out the correct device UUIDs. First, get a list of your device
IDs with lsblk -f it should look something like this:
NAME FSTYPE LABEL UUID MOUNTPOINT
nvme0n1
├─nvme0n1p1
├─nvme0n1p2 vfat AB24-1550 /boot/efi
├─nvme0n1p3 crypto_LUKS 434a512a-1b76-449e-8cb0-f93aee46e85c
│ └─cryptboot ext4 5fe2b9c5-ac2b-4f6e-8f3e-5e45c45d0b02 /boot
└─nvme0n1p4 crypto_LUKS a86c6534-6643-4afa-b3ae-c78a0a5dc50f
└─cryptlvm LVM2_member heTIE6-0pLH-8J8Y-67T7-1vPW-4f1V-SqHeOA
├─MyVolGroup-root ext4 49a833a2-4a3b-4a1b-a7d9-75ab50910a8e /
└─MyVolGroup-home ext4 ec626537-c6a5-4df9-9ad9-3a344bc8c86f /home
You will need the UUID from the device 4th partition (in this example a86c6534-6643-4afa-b3ae-c78a0a5dc50f) and the
UUID of MyVolGroup-root (in this example 49a833a2-4a3b-4a1b-a7d9-75ab50910a8e). Open the GRUB config file with vi /etc/default/grub
and add these two lines with your UUIDs.
GRUB_CMDLINE_LINUX="cryptdevice=UUID=[4th partition UUID]:cryptlvm root=UUID=[MyVolGroup-root UUID]"
GRUB_ENABLE_CRYPTODISK=y
Finally the GRUB_CMDLINE_LINUX line should look like this line with your UUIDs.
GRUB_CMDLINE_LINUX="cryptdevice=UUID=a86c6534-6643-4afa-b3ae-c78a0a5dc50f:cryptlvm root=UUID=49a833a2-4a3b-4a1b-a7d9-75ab50910a8e"
Generate initramfs
The last step is to generate a new initramfs and the GRUB boot loader. The first one is done with mkinitcpio -p linux
and the second one with the following lines (replace [your device] with your device e.g. nvme0n1):
grub-install --target=i386-pc --recheck /dev/[your device]
grub-install --target=x86_64-efi --efi-directory=/boot/efi --bootloader-id=GRUB --recheck
grub-mkconfig -o /boot/grub/grub.cfg
Add the crypto_keyfile.bin to the crypttab, otherwise you have to unlock the boot partition twice. Open the file with
vi /etc/crypttab and add the following line (replace [UUID 3rd partition] with the UUID of the 3rd partition e.g. 434a512a-1b76-449e-8cb0-f93aee46e85c ).
cryptboot UUID=[UUID 3rd partition] /crypto_keyfile.bin luks
It should look like this with your UUID of the 3rd partition.
cryptboot UUID=434a512a-1b76-449e-8cb0-f93aee46e85c /crypto_keyfile.bin luks
Configure ykde.conf
Open the file with vi /etc/ykde.conf and enable/set YKFDE_LUKS_NAME="cryptlvm" and YKFDE_DISK_UUID=[4th partition UUID]
(replace [4th partition UUID] with the UUID of the 4th partition e.g. a86c6534-6643-4afa-b3ae-c78a0a5dc50f).
Feel free to modify it to your needs e.g. enable TRIM (but be warned, there are potential security implications) support.
It should look something like this
# Configuration for yubikey-full-disk-encryption. ("") means an empty value.
### *REQUIRED* ###
# Set to non-empty value to use 'Automatic mode with stored challenge (1FA)'.
YKFDE_CHALLENGE="8fa0acf6233b92d2d48a30a315cd213748d48f28eaa63d7590509392316b3016"
# Use 'Manual mode with secret challenge (2FA)'.
YKFDE_CHALLENGE_PASSWORD_NEEDED="1"
# Choose YubiKey slot configured for 'HMAC-SHA1 Challenge-Response' mode. Possible values are "1" or "2".
YKFDE_CHALLENGE_SLOT="2"
### OPTIONAL ###
# Set partition UUID. Leave empty to use 'cryptdevice' kernel parameter.
YKFDE_DISK_UUID="a86c6534-6643-4afa-b3ae-c78a0a5dc50f"
# Set LUKS encrypted volume name. Leave empty to use 'cryptdevice' kernel parameter.
YKFDE_LUKS_NAME="cryptlvm"
# If left empty this will be set as "/dev/disk/by-uuid/$YKFDE_DISK_UUID" -- device to unlock with 'cryptsetup luksOpen'.
#YKFDE_LUKS_DEV=""
# Optional flags passed to 'cryptsetup luksOpen'. Example: "--allow-discards" for TRIM support. Leave empty to use cryptdevice kernel parameter.
#YKFDE_LUKS_OPTIONS=""
# Number of times to assemble passphrase and run 'cryptsetup luksOpen'. Defaults to "5".
#YKFDE_CRYPTSETUP_TRIALS="5"
# Number of seconds to wait for inserting YubiKey, "-1" means 'unlimited'. Defaults to "30".
#YKFDE_CHALLENGE_YUBIKEY_INSERT_TIMEOUT="30"
# Number of seconds passed to 'sleep' after succesful decryption. Defaults to empty, meaning NO sleep.
#YKFDE_SLEEP_AFTER_SUCCESSFUL_CRYPTSETUP=""
# Enable verbose output. It will print all secrets to terminal. Use only for debugging.
#DBG="1"
Test it
It's time to check you settings with a graceful reboot. If you have done all things right you will be asked for your boot parition password to see the GRUB boot menu and after that the YubiKey password with YubiKey touch button to unlock the root partition.
Good luck! Don't worry if something doesn't work, simply boot from the Arch Linux medium, install the necessary software to mount your encrypted partitions and check the configs. Maybe an UUID is wrong.
Now you can setup your Arch Linux e.g. create own user or add additional stuff en / de. The next chapter describes how to setup UEFI secure boot. The last piece to bullet proof your full disk encryption.