Curtis Free

Blog

Using the TrueCrypt CLI @ 04 Jul 2011

TrueCrypt is a great utility for hiding sensitive data – whether in an encrypted disk image or on an entire encrypted partition.

I encourage you to check out TrueCrypt, but that is not the point of this post.

Most TrueCrypt users are likely accustomed to its GUI. In fact, I very much like it. That said, some users do not realize that there is also a command-line interface (CLI) to TrueCrypt.

The key to using TrueCrypt from a terminal is the -t flag – which signals to the utility that you wish to use its textual interface.

After an encrypted volume has been created (a task that can also be accomplished via terminal), the two most common tasks will be mounting and unmounting the volume.

Mounting is simple and is the "default" option (requiring no special flags/commands). Simply tell TrueCrypt the location of the encrypted volume (disk image or device) and the mountpoint:

% truecrypt -t /dev/sdc /media/my_volume
Enter password for /dev/sdc:
Enter keyfile [none]:
Protect hidden volume (if any)? (y=Yes/n=No) [No]:
Enter your user password or administrator password:

Note that this makes it easy to choose an arbitrary mountpoint for the volume (rather than the default, which for me is /media/truecrypt1 for the first mounted volume). You can use a more complex command to avoid some of the prompts seen in that example.

Dismounting is also a simple task:

% truecrypt -t -d /media/my_volume
Enter your user password or administrator password:

For a full description of how to use TrueCrypt's CLI, check out the built-in help (N.B., there's no man page):

% truecrypt --help # Opens GUI containing help info and prints to terminal.

% truecrypt -t --help # Prints to terminal only.

% truecrypt -t --help | less # Nicer. :-)

If you begin using the CLI interface regularly, then do yourself a little favor and add an alias to your shell config: alias truecrypt='truecrypt -t'.