Re: [dm-crypt] Failed to setup dm-crypt key mapping for device cryptfile.

[Milan Broz <gmazyland@gmail.com>]

On 03/29/2016 11:04 PM, Yuriy M. Kaminskiy wrote:
> Nicolas Bock <nicolasbock@gmail.com>
> writes:
> 
>> cryptsetup fails on a new OS install for some reason, and I can't
>> figure out what is missing. What I see is the following:

What version are you using?

>>
>> $ dd if=/dev/zero bs=1M count=1 of=cryptfile
>> $ sudo cryptsetup -v luksFormat cryptfile
...
cryptsetup -v luksFormat cryptfile --use-urandom

WARNING!
========
This will overwrite data on cryptfile irrevocably.

Are you sure? (Type uppercase yes): YES
Enter passphrase: 
Verify passphrase: 
Device cryptfile is too small. (LUKS requires at least 1049600 bytes.)
Command failed with code 22: Device cryptfile is too small. (LUKS requires at least 1049600 bytes.)

That is pretty clear error message :)

Just use bigger image.

>>
>> WARNING!
>> ========
>> This will overwrite data on cryptfile irrevocably.
>>
>> Are you sure? (Type uppercase yes): YES
>> Enter passphrase:
>> Verify passphrase:
>> Failed to setup dm-crypt key mapping for device cryptfile.
>                                        ^^^^^^^^^^
>> Check that kernel supports aes-xts-plain64 cipher (check syslog for more info).
>> Command failed with code 22: Failed to setup dm-crypt key mapping for
>> device cryptfile.
>   ^^^^^^
>> Check that kernel supports aes-xts-plain64 cipher (check syslog for more info).
>>
>> Neither dmesg nor journalctl shows anything in the logs that seems to
>> be related to this failure. As far as I can tell all cryptographic API
>> modules are included in the kernel. How can I go about debugging this
>> further?

1) use newer version of cryptsetup
2) always report versions (cryptsetup, kernel), distro
3) paste debug log (add --debug to failing commands, it includes 2) as well)
 
> 
> I'd guess it wants block device, instead of file. man 8 losetup.
> Something like this (unchecked):

Loop is automatically allocated in recent versions of cryptsetup, you can
use file image directly (no need dance with losetup).
Milan