[SOLVED] Turecrypt 6.2a error on Vector lite 6.0

mikepeters76 · 07-26-2009, 08:59 AM

I am getting the following error when I am trying to mount a truecrypt volume on Vector lite 6.0:

Quote:

Error: device-mapper: reload ioctl failed: Invalid argument
Command failed

I know the volume works as I can mount it on my Ubuntu box.
I compiled Truecrypt on the Vector box, reading the Readme I have only come up with a device-mapper issue but I have kernel 2.6.27.12. which should mean I don't need a kernel patch. Any suggestions?

Cheers in advance.

Simon Bridge · 07-27-2009, 08:47 AM

http://en.gentoo-wiki.com/wiki/TrueCrypt

Quote:

If TrueCrypt gives you an error when mounting volume:

device-mapper: reload ioctl failed: Invalid argument
Command failed

you need to add XTS and/or LRW support in the kernel. See Requirements.

If you are positive that you have XTS and/or LRW support in the kernel but still get the above error, it may be necessary to disable kernel cryptographic services when mounting altogether:
truecrypt -m=nokernelcrypto volume mountpoint

Of course you may add any other necessary option on the commmand line as well. Note that truecrypt will have decreased performance when using this option.

mikepeters76 · 07-30-2009, 10:30 PM

Simon, thx. Your reply made me recompile my kernel with LRW support. XTS was already included in my current kernel.

What I did find out was that I could create a volume with Truecrypt which used XTS and that worked fine on my VL box as well as my Windoz (I have to keep one for work).

Could you explain, or rather point me to some resources that could explain the difference between LRW and XTS, how they function eg, do they pass data to the encryption algorithm or do they do the processing etc. Naturally I'll google myself.

I noted that when a volume was created with XTS it says Secondary Key size (XTS Mode) 512 bits and with LRW there is no secondary key but a Tweak Key Size(LRW Mode) 128 bits. Also the primary key size is smaller with LRW. Is XTS preferable for that reason? Is XTS inherently better?

mikepeters76 · 07-30-2009, 10:36 PM

Simon thx again. I found the answers I needed; Wikipedia is my friend;
http://en.wikipedia.org/wiki/TrueCrypt
http://en.wikipedia.org/wiki/Disk_encryption_theory

Simon Bridge · 07-30-2009, 10:44 PM

Well done - don't forget to find someone else to help.

mikepeters76 · 07-30-2009, 10:49 PM

naturally!