[dm-crypt] Android dm-crypt implementation and GNU/Linux

[Hannes <h2+lists2013@fsfe.org>]

Hi everyone,

I hope this is the right place to ask: I have a dualboot between Ubuntu
Arm and Android on a mobile device of mine. The data-partition is
encrypted using Android's builtin encryption and I'd like to share it
with the Ubuntu.
I have been searching quite a bit on the net, but I can't find answers
onto whether this is possible and how. It seems to me that Android's
dm-crypt implementation is custom (no LUKS...) and implemented in VolD.
Am I right in assuming there is no way to make cryptsetup unlock the
partition?
And do you know of a standalone implementation that can decrypt the
partition on a GNU/Linux system? I have come accross bruteforce attack
program[1] that runs on a regular GNU/Linux, but I think that works
directly on the footer of the partition and doesn't have any magic
beyond that.
I thought a standalone implementation should exist somewhere, as it
seems unlikely the implementation was developed inside Android's VolD.

Thanks for your help!

Best,
Hannes

[1]
https://github.com/santoku/Santoku-Linux/blob/master/tools/android/android_bruteforce_stdcrypto/bruteforce_stdcrypto.py