Why does Truecrypt ask for administrator password?

Question

When I login on my Ubuntu system a script will mount a truecrypt container. To decrypt the container I have of course to enter the decryption password. But Truecrypt also asks for my "administrator password". Why does Truecrypt ask for my administrator password and how can I disable this?

This is the script which runs on startup:

#!/bin/sh -e
/usr/bin/truecrypt /media/windows/data.tc /media/data
/usr/bin/dropbox start

/media/windows is a NTFS partition. /media/data is writable by the user.

Answer 1

TrueCrypt asks you for a password because mounting a filesystem requires superuser privileges. Do not circumvent it by allowing to run truecrypt as root without password, this is insecure as a malicious script can get elevated privileges by mounting a special-crafted container, and gain root privileges from it (e.g. setsuid binaries on in an ext2 filesystem or mounting on /).

Answer 2

Here is a quick fix you can use:

sudo visudo 

Add the line <yourusername> ALL=NOPASSWD: /usr/bin/truecrypt and save the file. truecrypt wont ask for your admin password anymore for . It quick and dirty, probably not safe, but works.