tcplay

From ArchWiki
The printable version is no longer supported and may have rendering errors. Please update your browser bookmarks and please use the default browser print function instead.

Related articles

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