This is a cross platform dmg decryption tool. Maintained by Drake Allegrini, but credit goes to its original owner.

To build, run "make linux"
To install, run "sudo make install"
To run, run "vfdecrypt"
To clean, run "make clean"
To uninstall, run "sudo make uninstall"

Usage: vfdecrypt -i in-file [-p password] [-k key] -o out-file

NOTICE: The -i and -o flags are extremely important, as without them, the program will never terminate unless forced to.
NOTICE: ONLY the -k -i and -o flags have been tested.

Depends:
libssl0.9.8

Example: 
Decrypting iOS 4 in your home directory.
Once the program is compiled and installed, run:

"vfdecrypt -i name_of_root_filesystem.dmg -k ec6eb0268c4e9f8ab9d003f601e8f4b36f4fc4311c61e5ebed07ce718424ffee7e7d924d -o decrypted.dmg"