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Arch Linux Full Encryption Installation Guide

·497 words·3 mins
Security Linux Arch Linux Linux Encryption
Nathan Higley
Author
Nathan Higley
just a guy who likes cyber
Table of Contents

Arch Linux w/ Fully Encrypted Filesystem
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This guide will show step by step how to create a clean Arch Linux install with a fully encrypted filesystem. This means that even the boot partition will be encrypted. The only unencrypted partition on the disk will be the EFI partition which could be configured later to use secure boot.

Assuming an EFI system with GPT disk.

Basic Install Stuff
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Make sure you can hit the outside world:

ping google.com

If not run dhcpcd:

dhcpcd

Set the time:

timedatectl set-ntp true

Setup the Disk (where the magic happens)
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Create Partitions
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Assuming /dev/sda is the device you want to install to.

parted /dev/sda

mklabel gpt

mkpart ESP fat32 1MiB 200MiB

set 1 boot on

name 1 efi

mkpart primary 800MiB 100%

set 2 lvm on

name 2 lvm

print

Setup LUKS
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Encrypt the partition

cryptsetup luksFormat –type luks1 /dev/sda2

Open the partition

cryptsetup open /dev/sda2 encrypted-lvm

Setup LVM
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Create a Physical Volume

pvcreate /dev/mapper/encrypted-lvm

Create a volume group

vgcreate arch /dev/mapper/encrypted-lvm

Create logical volumes in group

lvcreate -n home -L <SIZE>G arch

lvcreate -n root -L <SIZE>G arch

lvcreate -n boot -L 600M arch

lvcreate -n swap -L <SIZE> -C y arch

Format Partitions
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Format the EFI partition

mkfs.fat -F32 /dev/sda1

Format the Volume Groups

mkfs.ext4 -L boot /dev/mapper/arch-boot

mkfs.btrfs -L root /dev/mapper/arch-root

mkfs.btrfs -L home /dev/mapper/arch-home

mkswap /dev/mapper/arch-swap

Mount Partitions
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Configure Swap

swapon /dev/mapper/arch-swap swapon -a; swapon -s

Mount the filesystem

mount /dev/mapper/arch-root /mnt

mkdir -p /mnt/{home,boot}

mount /dev/mapper/boot /mnt/boot

mount /dev/mapper/arch-home /mnt/home

mkdir /mnt/boot/efi

mount /dev/sda1 /mnt/boot/efi

Check how everything is mounted

lsblk -f

Install the Base System
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Install base packages

pacstrap /mnt base efibootmgr btrfs-progs grub linux-zen linux-firmware lvm2

Generate Fstab

genfstab -U -p /mnt > /mnt/etc/fstab

Chroot into new install

arch-chroot /mnt /bin/bash

Configure the Install
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Normal Things
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Set the time zone

ln -sf /usr/share/zoneinfo/Region/City /etc/localtime

hwclock –systohc

Localization Uncomment “en_US.UTF-8 UTF-8” from /etc/locale.gen

locale-gen

echo “LANG=en_US.UTF-8” > /etc/locale.conf

Set the hostname

echo “hostname” > /etc/hostname

Edit /etc/hosts to

127.0.0.1	localhost
::1	        localhost
127.0.1.1	hostname.localdomain	hostname

Encryption Unlock
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Generate a keyfile for the root filesystem:

dd bs=512 count=4 if=/dev/random of=/root/encrypted-lvm.keyfile iflag=fullblock

chmod 000 /root/encrypt-lvm.keyfile

cryptsetup -v luksAddKey /dev/sda2 /root/encrypted-lvm.keyfile

Edit /etc/mkinitcpio.conf and add keyboard keymap encrypt lvm2 to hooks and add keyfile to files

FILES=(/root/encrypted-lvm.keyfile)
HOOKS=(base udev autodetect keyboard keymap consolefont modconf block encrypt lvm2 filesystems fsck)

Then generate the initramfs image:

mkinitcpio -p linux-zen

Secure the embedded keyfile:

chmod 600 /boot/initramfs-linux*

Configure grub, edit /etc/default/grub:

GRUB_ENABLE_CRYPTODISK=y
GRUB_CMDLINE_LINUX="... cryptdevice=/dev/sda2:encrypted-lvm ... cryptkey=rootfs:/root/encrypted-lvm.keyfile"

Install grub:

grub-install –target=x86_64-efi –efi-directory=/boot/efi –bootloader-id=GRUB –recheck

grub-mkconfig -o /boot/grub/grub.cfg

Final Cleanup
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Set a root password

passwd Add a normal user account if desired.

Reboot into New Install
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exit

umount -R /mnt

reboot

The system should be configured with full disk encryption and an encrypted boot partition.

References
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  1. Installation guide - ArchWiki
  2. dm-crypt/Encrypting an entire system - ArchWiki
  3. Install Arch Linux with full hard drive encryption using luks encryption | ComputingForGeeks