Did you not RTFA? The file system keys are stored in the SoC secure storage area and there are no facilities for retrieving them, meaning you must perform the d

Did you not RTFA? The file system keys are stored in the SoC secure storage area and there are no facilities for retrieving them, meaning you must perform the decryption attempts with the phone's own SoC. Of course an iCloud backup file is another matter... At least they are turning on two factor auth for that, but it's a difficult problem if someone has your password and the keys are on a phone that you no longer have.