Re: [gentoo-user] Re: [OT crypto] How to encrypt a directory without root?

On Tue, Jan 05, 2010 at 04:09:03PM -0600, Harry Putnam wrote:

> For example, if I wanted a forgotten password laying in a text file
> but encfs encrypted and on the remote.  When for one or another reason
> I cannot get it from the home machine.

I hate saying something when I don't know the full circumstances, but
here is how I do mine, and how I have recovered data from the backup.
I mount the plaintext with this command (actual details have been
changed because I do it in a shell script which does other things):

    encfs ~/.encrypted ~/.plaintext

~/.encrypted is the encrypted dir, ~/.plaintest is what I lok at when
I want to see the plaintext.  I have various symlinks elsewhere which
point into ~/.plaintext.

When I backup this data, I only backup ~/.encrypted.  In fact, since
backup is done as a part of root's nightly backup, and root cannot
look into ~/.plaintext, ~/.encrypted is all that can be backupped (did
I just invent a new verb? :-).

Now once I lost a file which I knew existed in the backup.  All I had
to do was

    1.  As root, mount the backup, in this case as /mnt/backup.

    2.  As myself, mount as usual but change the names:

    	encfs /mnt/backup/home/felix/.encrypted ~/tmp/plaintext

    3.  Copy the file as plaintext:

    	cp -p ~/tmp/plaintext/path/to/file ~/.plaintext/path/to/file

Of course, if you backup as yourself, the root step is easily adjusted
to yourself.

It's been so long since I set this up that I do not remember the
details.  There's a kernel module, maybe dm-crypt.  You probably have
to enable something in the kernel config.  But once done, it's easy as
pi and just as tasty, and I really like the fact that root cannot get
access to the plaintext.  For some reason, that just tinkles me pink.

-- 
            ... _._. ._ ._. . _._. ._. ___ .__ ._. . .__. ._ .. ._.
     Felix Finch: scarecrow repairman & rocket surgeon / felix@×××××××.com
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I've found a solution to Fermat's Last Theorem but I see I've run out of room o