Encrypted file systems¶
See mzlinux: Encrypted File System
DM-Crypt¶
DM-crypt encrypted loopback file device.¶
An example of creation and use of an aes encrypted loopback file device.
Fill a file with random bits:
dd if=/dev/urandom of=/tmp/crypt.img bs=1M count=10
Setup a loopback unencrypted device for the file system:
losetup /dev/loop0 /tmp/crypt.img
As the encryption is at the device mapper level the loop device is created unencrypted.
Setup the aes encrypted device mapper:
cryptsetup -v -c aes luksFormat /dev/loop0 cryptsetup luksOpen /dev/loop0 crypt
Create a filesystem and use it:
mkfs.ext3 /dev/mapper/crypt mkdir /tmp/mnt mount /dev/mapper/crypt /tmp/mnt echo "foo" >/tmp/mnt/file.txt cat /tmp/mnt/file.txt
Unmount the filesystem, close the device mapper and release the loopback device:
umount /tmp/mnt cryptsetup luksClose crypt losetup -d /dev/loop0