linuxkit/pkg/dm-crypt/crypto.sh
Christian Wuerdig a9bc7372de Adding dm-crypt as core pkg
Signed-off-by: Christian Wuerdig <christian.wuerdig@gmail.com>
2019-01-18 11:56:18 +13:00

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#!/bin/sh
set -e
help()
{
echo "Usage: $0 [options] <dm_name> <device>"
echo
echo "Options:"
echo " -l|--luks Use LUKS extension"
echo " -k|--key-file Name of the key file, default: key"
echo " <dm_name> Name of the device mapper file, the encrypted device will become available under /dev/mapper/<dm_name>"
echo " <device> The encrypted device (e.g. /dev/sda1, /dev/loop0, etc)"
echo
}
luks=false
key_file="key"
O=`getopt -l key-file:luks,help -- k:lh "$@"` || exit 1
eval set -- "$O"
while true; do
case "$1" in
-l|--luks) luks=true; shift;;
-k|--key-file) key_file=$2; shift 2;;
-h|--help) help; exit 0;;
--) shift; break;;
*) echo "Unknown option $1"; help; exit 1;;
esac
done
if [ -z "$1" ]; then
echo "Missing argument <dm_name>"
help
exit 1
fi
if [ -z "$2" ]; then
echo "Missing argument <device>"
help
exit 1
fi
dm_name=$1
device=$2
dmdev_name="/dev/mapper/$dm_name"
cipher="aes-cbc-essiv:sha256"
case "$key_file" in
/*) ;;
*) key_file="/etc/dm-crypt/$key_file" ;;
esac
if [ ! -f "$key_file" ]; then
echo "Couldn't find encryption keyfile $key_file!"
exit 1
fi
if [ ! -d "/run/cryptsetup" ]; then
echo "Creating cryptsetup lock directory"
mkdir /run/cryptsetup
fi
if [ $luks = true ]; then
echo "Creating dm-crypt LUKS mapping for $device under $dmdev_name"
if ! cryptsetup isLuks $device; then
echo "Device $device doesn't seem to have a valid LUKS setup so one will be created."
cryptsetup --key-file "$key_file" --cipher "$cipher" luksFormat "$device"
fi
cryptsetup --key-file "$key_file" luksOpen "$device" "$dm_name"
else
echo "Creating dm-crypt mapping for $device under $dmdev_name"
cryptsetup --key-file "$key_file" --cipher "$cipher" create "$dm_name" "$device"
fi
o=`blkid $dmdev_name`
if [ -z "$o" ]; then
echo "Device $dmdev_name doesn't seem to contain a filesystem, creating one."
# dd will write the device until it's full and then return with an error because "no space left"
dd if=/dev/zero of="$dmdev_name" || true
mkfs.ext4 "$dmdev_name"
else
echo "Device $dmdev_name seems to contain filesystem: $o"
fi