disk encryption (ext4)

This is a log on minimal setup of dm-crypt.

ref: Archwiki/dm-encrypt

# Setup

delete existing fs (use with caution).

wipefs -a /dev/sdx

Lock the partition with dm-crypt; see man page for options

crypt setup [Options] luksFormat /dev/sdx

Decrypt(open) the partition:

cryptsetup open /dev/sdx name

After unlocking the partition, it will be available at /dev/mapper/name

Create ext4 filesystem:

mkfs.ext4 /dev/mapper/name

# Mounting and Unmounting

# Mounting
cryptsetup open [device] [name]
mount -t [fstype] /dev/mapper/name /mnt/mntpoint

# Unmounting
umount /mnt/mntpoint
cryptsetup close [name]

# A SIMPLE SCRIPT

gpgwiz (I call it gpgwiz because i store my gpg keypair on a usb stick). The script itself doesn’t necessarily have anything to do with GPG.

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#!/bin/sh

# I WROTE ONLY FOR MY PERSONAL USE. IT WON'T WORK FOR YOU
# OUT OF THE BOX. TWEAK THE VARIABLES FOR YOURSELF.

UUID=xxxxgggg-cccc-bbbb-aaaa-ddddeeeeffff
NAME=GPGDATA
MOUNTPOINT=/mnt/GPGDATA_MNT

bold=$(tput bold)
normal=$(tput sgr0)

print_usage(){
    echo "${bold}USAGE${normal}"
    echo "gpgwiz open: unlock partition and mount"
    echo "gpgwiz close: unmount partition and lock"
}

open_dev(){
    echo "PREPARING DEVICE"
    echo "MOUNTPOINT: $MOUNTPOINT"
    cryptsetup open /dev/disk/by-uuid/$UUID $NAME
    mkdir -p /mnt/$MOUNTPOINT
    mount -t ext4 /dev/mapper/$NAME $MOUNTPOINT
    echo "ceating symbolinks... TODO"
}

close_dev(){
    umount $MOUNTPOINT
    cryptsetup close $NAME
}

if [ -z $1 ]
then
    print_usage
    exit
fi

if [ $1 == 'open' ]; then
    open_dev
elif [ $1 == 'close' ]; then
    close_dev
else
    print_usage
fi