[vox-tech] Encrypted CDROM

[Michael J Wenk]

On Wed, Aug 03, 2005 at 12:44:52PM -0700, Richard Harke wrote:
> Using loopback and cryptsetup (which uses the device mapper)
> I created an encrypted file system about the size of a CDRom. I put
> some files into this file system then I burned a CD using cdrecord.
> No error indications so far. Now I want to read the CD to verify
> whats on it. When I do a cryptsetup, I get an error. The command is
> 
> cryptsetup create --size=1431552 aname /dev/cdrom
> 
> The error I get is Invalid argument to an ioctl call. The ioctl call
> is trying to load the table to the mapper device. I ran strace but
> didn't get any more info. I've looked at the source but so far
> I haven't figured it out.
> 
> Does any one out there have any ideas?
> 
> Richard Harke
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>

All I have is a possible workaround.  

dd if=/dev/cdrom of=tmp.iso bs=64k


Then run the cryptsetup on the iso file.

More than likely(this is just a stab btw, I am not completely sure of
what I am talking about and I am going off of memory of how the ioctl's
interface with the driver on linux) what's happening is the ioctl called 
by the command is not valid with the device in question.  If you make
the device into a file and then try it with the file, it *may* work. 

Mike