Full disk encryption secure boot
This material is work-in-progress ... Do not follow instructions here until this notice is removed. |
This guide is to explain step by step how to setup Alpine Linux with Full Disk Encryption using LUKS2, /boot & / together on the same partition, encrypted swap for hibernation on a nvme drive, with UEFI & Secure Boot. The goal of this guide is to follow the KISS principle, lvm can be added, another file system can be used, multiple partitions for /home; /var/log etc.. can also be added, if running everything in one partition is not meeting your requirements.
Sequence of Events
- Installing packages
- Partitioning the disk
- Configuring LUKS
- Mounting points and File System
- Installing Alpine
- Grub settings
- mkinitfs settings & modules
- Configuring Secure Boot
Installing packages
To facilitate the partitioning we will use gdisk :
# apk add lsblk gptfdisk
For encryption, we will use cryptsetup :
# apk add cryptsetup
For using and managing UEFI, multiple packages are needed :
# apk add e2fsprogs grub grub-efi
Partitioning the disk
Let's assume the disk is /dev/nvme0n1 and no partition is present, we will create three partitions :
- one for UEFI
- one for /
- one for swap (hibernation)
# gdisk /dev/nvme0n1 GPT fdisk (gdisk) version 1.0.9.1 Partition table scan: MBR: protective BSD: not present APM: not present GPT: present Found valid GPT with protective MBR; using GPT. Command (? for help): d No partitions Command (? for help): n Partition number (1-128, default 1): First sector (2048-1000215182, default = 2048) or {+-}size{KMGTP}: Last sector (2048-1000215182, default = 1000214527) or {+-}size{KMGTP}: 512M Current type is 8300 (Linux filesystem) Hex code or GUID (L to show codes, Enter = 8300): ef00 Changed type of partition to 'EFI system partition' Command (? for help): n Partition number (2-128, default 2): First sector (1048577-1000215182, default = 1050624) or {+-}size{KMGTP}: Last sector (1050624-1000215182, default = 1000214527) or {+-}size{KMGTP}: 16G Current type is 8300 (Linux filesystem) Hex code or GUID (L to show codes, Enter = 8300): 8200 Changed type of partition to 'Linux swap' Command (? for help): n Partition number (3-128, default 3): First sector (1048577-1000215182, default = 33556480) or {+-}size{KMGTP}: Last sector (33556480-1000215182, default = 1000214527) or {+-}size{KMGTP}: Current type is 8300 (Linux filesystem) Hex code or GUID (L to show codes, Enter = 8300): 8309 Changed type of partition to 'Linux LUKS' Command (? for help): w Final checks complete. About to write GPT data. THIS WILL OVERWRITE EXISTING PARTITIONS!! Do you want to proceed? (Y/N): Y OK; writing new GUID partition table (GPT) to /dev/nvme0n1. The operation has completed successfully.
Configuring LUKS
# cryptsetup -v -c aes-xts-plain64 -s 512 --hash sha512 --pbkdf pbkdf2 --iter-time 5000 --use-random luksFormat /dev/nvme0n1p2 WARNING! ======== This will overwrite data on /dev/nvme0n1p2 irrevocably. Are you sure? (Type 'yes' in capital letters): YES Enter passphrase for /dev/nvme0n1p2: Verify passphrase: Key slot 0 created. Command successful. cryptsetup -v -c aes-xts-plain64 -s 512 --hash sha512 --pbkdf pbkdf2 --iter-time 5000 --use-random luksFormat /dev/nvme0n1p3 WARNING! ======== This will overwrite data on /dev/nvme0n1p3 irrevocably. Are you sure? (Type 'yes' in capital letters): YES Enter passphrase for /dev/nvme0n1p3: Verify passphrase: Key slot 0 created. Command successful.
Mounting points and File System
Open the LUKS partitiond we just created:
# cryptsetup luksOpen /dev/nvme0n1p2 nvme0n1p2-crypt # cryptsetup luksOpen /dev/nvme0n1p3 nvme0n1p3-crypt
Create vfat file system for UEFI partition:
# mkfs.vfat /dev/nvme0n1p1
Create ext4 file system for / partition:
# mkfs.ext4 /dev/mapper/nvme0n1p2-crypt
Create ext4 file system for swap partition:
# mkfs.ext4 /dev/mapper/nvme0n1p3-crypt
Create mounting points and mount partitions : Mount / partition to /mnt :
# mount -t ext4 /dev/mapper/nvme0n1p2-crypt /mnt
Create /boot/efi:
# mkdir /mnt/boot/efi -p
Mount UEFI partition to /mnt/boot/efi :
# mount -t vfat /dev/nvme0n1p1 /mnt/boot/efi
Activate SWAP:
# mkswap /dev/mapper/nvme0n1p3-crypt # swapon /dev/mapper/nvme0n1p3-crypt
Check partition scheme:
# lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINTS loop0 7:0 0 105.2M 1 loop /.modloop sda 8:0 1 7.6G 0 disk /media/sda ├─sda1 8:1 1 148M 0 part └─sda2 8:2 1 1.4M 0 part nvme0n1 259:0 0 476.9G 0 disk ├─nvme0n1p1 259:1 0 511M 0 part /mnt/boot/efi ├─nvme0n1p2 259:2 0 15.5G 0 part │ └─nvme0n1p2-crypt 253:0 0 15.5G 0 crypt /mnt └─nvme0n1p3 259:3 0 460.9G 0 part └─nvme0n1p3-crypt 253:1 0 460.9G 0 crypt [SWAP]
Installing Alpine
# setup-disk -m sys /mnt/ MOUNTPOINT=/mnt setup-alpine