Bug in build-gpgmount.sh

[Jari Ruusu <jari.ruusu@pp.inet.fi>]

Loop-AES contains build-gpgmount.sh script that can be used to create a
program to mount loop devices using GnuPG encrypted loop key. Intent is for
created program to start both gpg and mount programs in a way that non-root
users decrypt loop encryption key from GnuPG encrypted file without non-root
users having access to actual loop encryption key.

Latest released version (from loop-AES-v1.6d tarball) has a bug that reveals
the loop encryption key to non-root users: all they need to do is add a line
"output fubar.txt" to their gpg options file. That causes gpg to write the
loop encryption key to fubar.txt file instead of piping it to mount.

A fix is to pass "--options /dev/null" option to gpg so it won't read
non-root supplied options file. A fixed version of the script is attached
to this mail.

Regards,
Jari Ruusu <jari.ruusu@pp.inet.fi>

build-gpgmount.sh.gz

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