NAME

Crypt::AppleTwoFish -- two Apple iTMS/iTunes key descrambling algorithms

DESCRIPTION

The first algorithm appears to have only cursory resemblance to Bruce Schneier's blowfish and twofish algorithms in that it too has a table-based decoder.

The second algorithm is more standard encryption using S-box type permutations and lookup tables, and might have started out something like Twofish or Blowfish.

SYNOPSIS

for iTMS usages:

use Crypt::AppleTwoFish;

my $scrambled_key = '=sixteen uchars=';

my $apple_twofish = new Crypt::AppleTwoFish(key => $scrambled_key);

my $descrambled_key = $apple_twofish->decrypted_for_iTMS;

my $descrambled_another_way = $apple_twofish->decrypted_for_DRMS;


..and for iTunes 7 compatible usages:

Functions cloned from lower level compiled code which was likely intended
to be difficult to reconstruct cannot easily be given sensible names. Ada 
Pro is good, but dull.  We chose to be amused during the tedium by coming 
up with function names from a vegetable farm. 

For actual usage, see also:

iTunes::Sid.

METHODS

new

Call with the key as a scalar argument. When passed (LWP simulating iTunes) over iTMS, encrypted M4P keys for your purchased music are currently 16 unsigned chars in length.

decrypted_for_iTMS

Returns the unscrambled key for use with the Apple Music Store.

decrypted_for_DRMS

Returns the unscrambled key for use with iTunes/iPod DRM.

key

Get/set initial key.

int_table

Get/set veggie integer table.

byte_table

Get/set veggie byte table.

veggie

Get/set veggie.

hwID

Get/set hardware ID (MAC address or other machine based data). 6 bytes.

keyID

Get/set key ID.  4 bytes.

userID

Get/set user ID.  4 bytes.

plant_veggies

Key munging, spring season

harvest_veggies

Key munging, harvest season

AUTHOR

iTMS decrambler adapted from FairKeys 0.5, by Jon Lech Johansen, and from 
the alterate scramble table found by FutureProof. 

Veggie Tales algorithm courtesy of Ada and other anonymous pros :-).

SUPPORT

Questions, feature requests and bug reports should go to <wherrera@skylightview.com>.

COPYRIGHT

  Copyright (c) 2005, 2008 William Herrera. All rights reserved.  

  Licensing Terms

  a) The terms of Perl itself, plus the following:

  b) UNDER NO CIRCUMSTANCES CAN THIS CODE BE USED FOR CIRCUMVENTION OF ANY 
  TECHNOLOGICAL MEASURE WHICH EFFECTIVELY CONTROLS A PROTECTED MEDIA WORK 
  UNDER THE DCMA (USA, 1998) OR EU COPYRIGHT DIRECTIVE (EUCD, ARTICLE 6, 
  OF 2001), UNDER ANY OPERATING SYSTEM PLATFORM SUPPORTED BY APPLE COMPUTER 
  CORPORATION FOR ITS ITUNES OR IPOD PLAYER SOFTWARE IN ANY APPLE CORPORATION 
  DISTRIBUTED BINARY FORMAT OF ITUNES FOR THE PLATFORM UNDER WHICH THAT MEDIA 
  IS TO BE PLAYED. AS OF 2008, PROHIBITED PLATFORMS INCLUDE THE IPOD, IPHONE, 
  APPLE OS X, AND MICROSOFT WINDOWS, BUT NOT LINUX, BSD, OR SOLARIS.  UNDER NO 
  CIRCUMSTANCES CAN THE AUTHOR(S) OF THIS CODE BE HELD LIABLE FOR ANY 
  INFRINGEMENT INVOLVING THE PROHIBITED PLATFORMS ABOVE.

  c) Use, storage, or distribution of this code implies that you accept that 
  its intended purpose is legal and legitimate under any applicable US or EU 
  law, as above, and agree that any and all risk as to the quality, 
  performance, and legality of this code lies with you.