====== Encrypt file container with cryptsetup-luks for Fedora  ======

Make sure you have the package cryptsetup-luks installed.

As root.

Prepare an empty file container. Here 10MB.
  # dd if=/dev/zero of=encrypted_file.bin bs=1024k count=10

Find the first available loop device:
  # losetup -f
  /dev/loop0

Map file container with loop device (in this case /dev/loop0):
  # losetup /dev/loop0 encrypted_file.bin
 
Initialize and encrypt loop device (file container) 
  # cryptsetup --verify-passphrase luksFormat /dev/loop0

  WARNING!
  ========
  This will overwrite data on /dev/loop0 irrevocably.
  Are you sure? (Type uppercase yes): YES
  Enter LUKS passphrase: <Enter password>
  Verify passphrase: <Enter password>


The verify-passphrase parameter will ask for a password twice which will minimize risk of typos.\\
The default encryption cipher method (at compile time) can be printed with:
   # cryptseup --help

Create device-mapper mapping and open loop device
  # cryptsetup luksOpen /dev/loop0 encrypted_container  
  Enter passphrase for /dev/loop0: <Enter password>
  
To check status of device mapper:
  # cryptsetup status encrypted_container
  /dev/mapper/encrypted_container is active:
  cipher:  aes-cbc-essiv:sha256
  keysize: 256 bits
  device:  /dev/loop0
  offset:  2056 sectors
  size:    18424 sectors
  mode:    read/write

Time to create file system inside container:
  # mkfs.ext3 /dev/mapper/encrypted_container

Mount device mapper. In this case to mountpoint /mnt:
  # mount /dev/mapper/encrypted_container /mnt

Use file system\\
Remeber to umount and close after container after use so other have no chance to look into your encrypted container.

  # umount /mnt
  # cryptsetup remove /dev/mapper/encrypted_container
  # losetup -d /dev/loop0
  
===== Mounting an Existing Encrypted Container File =====
  
Get loop device:
  # losetup -f

Map loop device and container file:
  # losetup /dev/loop0 encrypted_file.bin

Create device-mapper
  # cryptsetup luksOpen /dev/loop0 encrypted_container  
  <Enter password>
  
Mount device-mapper
  # mount /dev/mapper/encrypted_container /mnt