Some of you may remember my OCLUG talk on tools for carrying encrypted
files on USB. Still on this topic, I'm wondering the best way (for the
moment just in Linux) to simply view the contents of an encrypted plain
text file (my password list!) in a way that doesn't leave a backup file
around, and clears memory etc.
The script below is a start. There are several notes at the end about
things I don't like about it. Perhaps someone knows a better way.
Ideally I want a set of cross-platform programs on my USB key with data
that let me view safely on practically any machine, though I recognize
that a machine that is compromised would be dangerous.
Suggest folk respond off-list and then I'll collect the answers in a few
days and post them in summary form. I'm sure someone has done this before.
# v -- view contents of encrypted text file
# first argument is name of file
# sudo mount -t tmpfs -o size=500k,nr_inodes=200,mode=0700 tmpfs
sudo mount -t tmpfs -o size=500k,nr_inodes=200 tmpfs /home/john/tspace
# Use backquote to execute date
echo "$tpw\n" > tpass
echo "$tpw\n" >> tpass
cat tpass | encfs -S ~/tspace/ ~/etspace/
echo "Destroy this?\n"
rm tpass # for security
cp $1.cpt ~/etspace/$1.cpt
ccrypt -d ~/etspace/$1.cpt
echo "Now scrub it\n"
echo "and unmount stuff\n"
sudo umount ~/etspace
sudo umount ~/tspace
mount # to check we have got rid of stuff
# This has a couple of problems:
## need sudo access for mounting
## need sudo access for unmounting
## need to sort out how to get file from subdir to correct location and
extract root of name