Re: [dm-crypt] Variable data offset for a LUKS volume that uses a detached header.

[Milan Broz <gmazyland@gmail.com>]

On 12/23/2015 01:10 PM, .. ink .. wrote:
>> I really do not want to workaround problems in other software by introducing
>> hacks in current version of LUKS.
>>
> 
> I agree and will probably settle with having a local patched version
> of cryptsetup.
> 
> Making progress on this front as i can now unlock a volume with
> offsets VeraCrypt volumes expects.
> 
> [root@ink mtz]# cryptsetup luksOpen veraCrypt.img --header=header.img rrr
> Enter passphrase for veraCrypt.img:
> 
> [root@ink mtz]# dmsetup table /dev/mapper/rrr
> 0 40704 crypt aes-xts-plain64 -master-key- 256 7:0 256
> 
> [root@ink mtz]# blkid /dev/mapper/rrr
> /dev/mapper/rrr: SEC_TYPE="msdos" UUID="706E-EE80" TYPE="vfat"
> [root@ink mtz]#
> 
> 
>> If you really want this, you can use existing API (open LUKS device/header,
>> get volume key, open device again in PLAIN mode and use the parameters).
>> Should be few lines of code.
>>
> 
> Like i said earlier,PLAIN volumes do not use crypt_format argument for
> the master key[1]

Sure, but activate_by_volume_key can be used here.

m.