How to get the FileVault recovery key?

I want to mount my (non-bootable) Filevault encrypted drive on Linux. I know the user-facing password to decrypt it, but not the recovery key. From what I've read, I assume that the recovery key is the actual XTS-AES-128 key. Linux can't decrypt the drive with a password, but it can with the AES key. There's obviously a way to obtain the recovery key given the password, since that's done every time you decrypt the drive with a password. Hence I need a way to get this recovery key.

Alternatively, a Filevault driver for Linux would also be a way to mount my encrypted drive.

Solution 1:

You may be able to use libfvde to access FileVault 2 encrypted drives on Linux.

OS X turns the password for the drive into a derived key by using PBKDF2. That derived key then unlocks the encrypted drive. I'm not aware of a way to display the key.