tcplay

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tcplay is a free, fully featured and stable TrueCrypt implementation including multiple keyfiles and cipher cascades.

Source: github project home

Installation

Install the tcplay package.

Encrypting a file as a virtual volume

Invoke 

$ losetup -f

to find the first unused loopback device; in this example, /dev/loop0.

Note: As of udev 181-5, the loop device module is no longer auto-loaded.

Create a new container foo.tc, 20M in size for instance, in the working directory: 

# fallocate -l 20M foo.tc
# losetup /dev/loop0 foo.tc
# tcplay -c -d /dev/loop0 -a whirlpool -b AES-256-XTS

Enter a secure password for the volume, and confirm the query to overwrite foo.tc with the new volume. tcplay will then write random data into the volume. Map the volume and create a filesystem on it in order to mount 

# tcplay -m foo.tc -d /dev/loop0
# mkfs.ext4 /dev/mapper/foo.tc
# mount /dev/mapper/foo.tc /mnt/truecrypt/

To unset the container, 

# umount /mnt/truecrypt
# dmsetup remove foo.tc
# losetup -d /dev/loop0

Mounting an existing container for a user

Consider /dev/loop0 the first unused loop device, foo.tc the TrueCrypt container, /home/you/truecrypt/ the desired mount point. The user you in this example has uid=1000 and gid=100. The steps for mounting the container as a virtual volume are:

  1. Associate loop device with the container
  2. Map the container to the loop device
  3. Mount the container in the filesystem

The following commands perform the above actions. 

# losetup /dev/loop0 foo.tc
# tcplay -m foo.tc -d /dev/loop0
# mount -o nodev,nosuid,uid=1000,gid=100 /dev/mapper/foo.tc /home/you/truecrypt/

Note, if the container uses ext4 or another filesystem that supports file ownership, the uid and gid parameters are not needed and will not work. Therefore the third command would be simply: 

 # mount -o nodev,nosuid /dev/mapper/foo.tc /home/you/truecrypt/

To reverse them: 

# umount /home/you/truecrypt/
# dmsetup remove foo.tc
# losetup -d /dev/loop0

Using tcplay-helper

The tcplay-helper script simplifies the process of creating, mounting and unmounting tc-play containers. The script is basic, but should work fine for most users wanting to work with simple secure tc-play containers.

The following command creates a 3Mb container called foo.tc. 

# tcplay-helper create foo.tc 3M

To mount the container file we can either mount it as root with the following command. The container will be mounted under /mnt/truecrypt/ 

# tcplay-helper open foo.tc

Alternatively, we can supply a username to mount the container as. 

# tcplay-helper open foo.tc archie

Finally, to close the container this command does the trick. 

# tcplay-helper close foo.tc

See also