On 12/11/2020 10.36, Milan Broz wrote:
> On 11/11/2020 20:16, Carlos E. R. wrote:
>> On 10/11/2020 17.22, Davide Marchi wrote:
>>> Hi to all,
>>>
>>> I'm wondering how to create a DVD or CDROM encrypted using dm-crypt.
>>> I've followed this tutorial, with no luck:
>>> http://www.sourcentral.org/luks/iso9660/
>>>
>>> and the DVD or cdrom created cannot be activated:
>>
>> Hum. I created encrypted DVD years ago with a similar procedure,
>> somewhat simpler. Basically, I created an empty file of the same size as
>> the CD or DVD, mounted it as a loop device, then I encrypted that loop
>> device, and then I formatted the resulting luks device with any
>> filesystem type I wished, typically XFS.
>>
>> This, so far, still works.
>>
>> Then I just burn that file to DVD.
>>
>> The final step is to mount and decipher the DVD - and this step failed,
>> but it was an XFS error if I remember correctly.
> 
> You cannot switch block size in XFS - if DVD reports 2k block and XFS
> was formatted with 4k block device, it will never work.

It worked several years ago, I have dozens of DVDs made this way.


> This is not a cryptsetup problem but the way how XFS works.
> 
> Try to run lsblk -t and compare reported sector size for DVD device and your
> original device. If it is the same, it should work even for XFS.

-- 
Cheers / Saludos,

		Carlos E. R.
		(from 15.1 x86_64 at Telcontar)