truecrypt fails to set up loop device
 

Hello, I'm using Zenwalk 6.4 and I've installed TrueCrypt 6.3a.
Everything works fine on the set up until the last stage when I get a message "Failed to set up a loop device......."
Anyone out there had any experience with this problem using TrueCrypt?
As usual, I'd be most grateful for any input.

Maybe this is a misleading/old error message. In my experience, recent versions of truecrypt use the device mapper infrastructure, so you should have kernel support for dm-crypt for using truecrypt.

Thanks zirias,
I don't think that this is an old message, I've tried to create a volume several times without a result.
I've also tried to use cryptkeeper and this appears to run perfectly, until I try to access anything I've put in the encrypted file. I put a file in the test folder and everything looks normal, I hide the folder and access it again with the password and it's empty. I'm wondering if I'm missing some dependencies although, as both applications were installed by netpkg, I shouldn't be.

I meant "old" as in "left in the codebase from times, when the loopback device was used". Did you try to set up an encrypted partition using cryptsetup (maybe luks)? If my assumption is correct, that dm-crypt support is missing in your kernel, this should fail, too. But if it works, there's another problem, no idea in this case.

Hello zirias,
When I try to run cryptsetup on my zenwalk box it won't recognise the command, looks like you're right. I wonder, is this a problem in all zenwalk installations, or is mine corrupt?

I think all that means is you don't have cryptsetup installed. Have you tried creating a loop device with the losetup command:

$ losetup /dev/loop0

You will probably get an error message unless you run the command as root. I'm guessing that's the problem you are having, i.e. truecrypt has inadequate permissions to setup a loop device. If running truecrypt as root solves the problem, then it's clearly a permission problem.

Uhm wait ... did you try creating a volume in a /file/ container? In that case, I assume kilgoretrout is right, I didn't even consider file containers because I never used them, but using a loop device for that really seems plausible.

Thanks kilgoretrout,
I am working as root when trying to run truecrypt and trying losetup results in this:
root[~]# losetup /dev/loop0
loop: can't open device /dev/loop0: No such file or directory
root[~]#

N.B. According to netpkg cryptsetup is installed, as are the dependencies.

Try doing:

# modprobe loop

Then see if you can create a loop device with losetup. If you can, try running truecrypt as root. Most kernels have loop support built into the kernel but some slack based distros compile loop support as a kernel module instead. When that's the case, you have to load the loop module first before you can create a loop device.

Edit: Just got to a machine with zenwalk on it and confirmed that you need to modprobe loop. Unfortunately, still get an error message when running losetup /dev/loop0. However, I was able to mount an iso on a loop device with:

# mount -o loop <path to iso> <mount point>

Running mount afterwards confirmed that the iso was mounted at the mount point through /dev/loop0 even though when I previously ran:

# losetup /dev/loop0

I got an error message. Given the above, I would suggest that you modprobe loop and then try running truecrypt as root.