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I have been using Truecrypt with a 32gb filesystem to keep important, personal, private files in. The idea is a stranger getting into my system cannot see any of those files, including Chrome cache, passwords, etc.

Working well, but I have discovered ecryptfs and am considering using it becuz it doesn't require a fixed size file or filesystem.

The way I use Truecrypt is when Gnome starts I get a prompt (/etc/gdm3/*Session files) along with a script to mount my Truecrypt filesystem.

I would like to do similar for ecryptfs. Installed it, created my ~/.Private and ~/Private filesystems with ecryptfs-setup-private and it works.

Unfortunately, it mounts automatically at login - bad. So, I researched some and see that removing ~/.ecryptfs/wrapped-passphrase disables that capability.

But now ecryptfs-mount-private says "ERROR: Encrypted private directory is not setup properly" - bad.
Also doing "sudo mount -t ecryptfs ~/.Private ~.Private" makes me answer all the same questions as ecryptfs-setup-private - I even created a file ~/.ecryptfsrc with appropriate stuff in it - no workee.

What I would like is for, at Gnome startup, for it to ask me for my (or root) password and my passphrase similar to what Truecrypt does now for me.

But, still have to figure out how to get a simple mount or ecryptfs-mount-private to work without hassle before getting there.

Any similar thoughts or issues?

Thanks,

Jim

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1 Answer 1

I am not an eCryptFS expert, to say the least, and I don't use gnome, but I set something like this up.

Removing the wrapped passphrase file will cause it not to mount when you log in, but only because it will also make your Private directory cryptographically inaccessible -- the wrapped-passphrase file is the "real" passcode that your typed-in passphrase/password decrypts so that the system can in turn decrypt your files. You can even symlink the wrapped passphrase file to some other location, say a removable SD card, so you can remove the card and thus disable the encrypted directory.

To disable automatic mounting, the method I used is to remove the .ecryptfs/auto-mount file (I also removed the auto-umount file because it unmounts the directory on session logout -- e.g. if you go to a vterm and log in and then log out, suddenly the directory is gone. You could have e.g. a gnome session script unmount it when you truly "log out" of the machine, but i'm the only user, so I don't worry about that.)

I then run a script that pops up a term window that runs ecryptfs-mount-private which asks for the password to unwrap the wrapped-passphrase file, as you describe.

If you actually deleted your wrapped passphrase (as opposed to renaming or moving), you'll have to recreate your Private directory.

Note that you'll want to make sure your swap space is encrypted as well, lest the OS spool data to that (this breaks hibernation, though, and maybe "sleep" as well, don't know.) Read up on "ecryptfs-setup-swap" for more. You may also want to encrypt /tmp for similar reasons. I did this (turns /tmp into a ram risk that could spool to swap -- so swap should be encrypted or this is risky):

$ sudo echo "tmpfs /tmp tmpfs defaults,noatime,mode=1777 0 0" >> /etc/fstab

...but that's out of scope for this question. Those complications (and the fact that ecryptfs is slower) are part of why people like block-level encryption like TrueCrypt, but I do appreciate the flexibility of ecryptfs.

Presumably, your wrapped-passphrase file was wrapped using your standard login password when you used the setup wizard. Most people want the encrypted directory to mount automatically for convenience: the files are still encrypted until they login with their password. Your question implies that you want to use a different password for the encrypted files for some reason. To do that, you'll need to change the password used for the wrapped passphrase file. To do that, I believe what you want to do is something like this (untested):

  • unmount the Private directory
  • run:

    $ ecryptfs-rewrap-passphrase ~/.ecryptfs/wrapped-passphrase

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