Ever got your display broken or had a backup of you Android's block devices and needed access to your files? Oh, of course, you enabled Android's device encryption...
With this tool, you can easily decrypt the block device on your PC.
You need to have at least the Linux headers installed, adjust the Makefile.
$ gmake
Now, you built android-decryptvol.
Assuming, your encrypted partition is $file and your password is p4ssw0rd,
this command mounts it at /mnt/somewhere:
# losetup -f --show $file
loop0
# android-decryptvol /dev/loop0 /mnt/somewhere p4ssw0rd
The program will tell you if something went wrong, e.g. you used the wrong password.
Then, copy your data and unmount the image:
# umount /mnt/somewhere
# dmsetup remove AndroidData
# losetup -d loop0