ADEPT DRM-protected decryption with fixes for more recent version of PyCrypto

Adept decrypt on Windows, OSX and Wine

Tested under on 2017-04 under wine, python-2.7.13.msi, pycrypto-2.6.win32-py2.7.exe

From https://thescienceofdestruction.wordpress.com/2011/08/10/downloading-and-decrypting-adobe-adept-drm-protected-ebooks-on-linux/ :

Fixes by rknop : https://thescienceofdestruction.wordpress.com/2011/08/10/downloading-and-decrypting-adobe-adept-drm-protected-ebooks-on-linux/#comment-696

This howto shows how to download eBooks using Adobe’s ADEPT DRM (Digital Rights Management) scheme on Linux and how to decrypt those books so that you can use your eBook viewer of choice to read them and copy them to any device you wish.

To download content protected with ADEPT, we need the Adobe Digital Editions eBook viewer. Sadly there is no Linux version, so we need to run the Windows version with Wine. Get the Windows installer from here.
Go to the folder where you downloaded the installer and run it with the command
wine setup.exe
After the installation, run Adobe Digital Editions straight from the installer or with the command
wine ~/.wine/drive_c/"Program Files/Adobe/Adobe Digital Editions/digitaleditions.exe"
In order to access DRM-protected content, you need to “authorize” your computer using the Adobe ID. You can get the ID by creating an account at the Adobe website here. Then in Adobe Digital Editions select “Authorize computer…” from the Library-menu and enter the ID and password.
Now we can actually download the book. For this we need a file with the .acsm-extension. This file contains the necessary information for Adobe Digital Editions to locate and download the book. You’ll probably get this file by clicking on the download link your eBook vendor provided. Save the file to disk. Now load the file by dragging its icon on the Adobe Digital Editions window. Adobe Digital Editions should now start downloading the book. After the download has finished, quit Adobe Digital Editions.
The DRM-protected pdf- or ePub-file should now be located in the folder ~/My Digital Editions. Next, we decrypt the DRM scheme. For this, we’ll use two Python-scripts: the key retrieval script ineptkey.pyw and the decryption script ineptpdf.pyw or ineptepub.pyw (depending on the file format). Copy the scripts into the same folder with the book. Unfortunately, as these scripts are for Windows and OSX only, we’ll again have to use Wine. To run the scripts, we need the Windows version of Python (get it from here) and the cryptography package PyCrypto (from here). The Python version should be at least 2.6 (I use 2.7 here, newer versions might work as well). Make sure that the PyCrypto version matches the Python one. Run the installers with the commands
wine msiexec /i python-2.7.2.msi
and
wine msiexec /i pycrypto-2.3.win32-py2.7.msi
Now, go to the folder with the book and the scripts and run the first script with the command
wine ~/.wine/drive_c/Python27/python.exe ineptkey.pyw
This will create the file adeptkey.der in the same folder. Now, run the second script with
wine ~/.wine/drive_c/Python27/python.exe ineptpdf.pyw
or
wine ~/.wine/drive_c/Python27/python.exe ineptepub.pyw
In the dialogue select the book as input file and name the output file what you like. Click on “Decrypt.”
Voila! You should now have the decrypted pdf- or ePub-file in the ~/My Digital Editions folder.

ineptepub.pyw

#! /usr/bin/python
# -*- coding: utf-8 -*-

# ineptepub.pyw, version 5.2
# Copyright © 2009-2010 i♥cabbages

# Released under the terms of the GNU General Public Licence, version 3 or
# later.  <http://www.gnu.org/licenses/>

# Windows users: Before running this program, you must first install Python 2.6
#   from <http://www.python.org/download/> and PyCrypto from
#   <http://www.voidspace.org.uk/python/modules.shtml#pycrypto> (make sure to
#   install the version for Python 2.6).  Save this script file as
#   ineptepub.pyw and double-click on it to run it.
#
# Mac OS X users: Save this script file as ineptepub.pyw.  You can run this
#   program from the command line (pythonw ineptepub.pyw) or by double-clicking
#   it when it has been associated with PythonLauncher.

# Revision history:
#   1 - Initial release
#   2 - Rename to INEPT, fix exit code
#   5 - Version bump to avoid (?) confusion;
#       Improve OS X support by using OpenSSL when available
#   5.1 - Improve OpenSSL error checking
#   5.2 - Fix ctypes error causing segfaults on some systems

"""
Decrypt Adobe ADEPT-encrypted EPUB books.
"""

from __future__ import with_statement

__license__ = 'GPL v3'

import sys
import os
import zlib
import zipfile
from zipfile import ZipFile, ZIP_STORED, ZIP_DEFLATED
from contextlib import closing
import xml.etree.ElementTree as etree
import Tkinter
import Tkconstants
import tkFileDialog
import tkMessageBox

class ADEPTError(Exception):
    pass

def _load_crypto_libcrypto():
    from ctypes import CDLL, POINTER, c_void_p, c_char_p, c_int, c_long, \
        Structure, c_ulong, create_string_buffer, cast
    from ctypes.util import find_library

    libcrypto = find_library('crypto')
    if libcrypto is None:
        raise ADEPTError('libcrypto not found')
    libcrypto = CDLL(libcrypto)

    RSA_NO_PADDING = 3
    AES_MAXNR = 14
    
    c_char_pp = POINTER(c_char_p)
    c_int_p = POINTER(c_int)

    class RSA(Structure):
        pass
    RSA_p = POINTER(RSA)
    
    class AES_KEY(Structure):
        _fields_ = [('rd_key', c_long * (4 * (AES_MAXNR + 1))),
                    ('rounds', c_int)]
    AES_KEY_p = POINTER(AES_KEY)
    
    def F(restype, name, argtypes):
        func = getattr(libcrypto, name)
        func.restype = restype
        func.argtypes = argtypes
        return func
    
    d2i_RSAPrivateKey = F(RSA_p, 'd2i_RSAPrivateKey',
                          [RSA_p, c_char_pp, c_long])
    RSA_size = F(c_int, 'RSA_size', [RSA_p])
    RSA_private_decrypt = F(c_int, 'RSA_private_decrypt',
                            [c_int, c_char_p, c_char_p, RSA_p, c_int])
    RSA_free = F(None, 'RSA_free', [RSA_p])
    AES_set_decrypt_key = F(c_int, 'AES_set_decrypt_key',
                            [c_char_p, c_int, AES_KEY_p])
    AES_cbc_encrypt = F(None, 'AES_cbc_encrypt',
                        [c_char_p, c_char_p, c_ulong, AES_KEY_p, c_char_p,
                         c_int])
    
    class RSA(object):
        def __init__(self, der):
            buf = create_string_buffer(der)
            pp = c_char_pp(cast(buf, c_char_p))
            rsa = self._rsa = d2i_RSAPrivateKey(None, pp, len(der))
            if rsa is None:
                raise ADEPTError('Error parsing ADEPT user key DER')
        
        def decrypt(self, from_):
            rsa = self._rsa
            to = create_string_buffer(RSA_size(rsa))
            dlen = RSA_private_decrypt(len(from_), from_, to, rsa,
                                       RSA_NO_PADDING)
            if dlen < 0:
                raise ADEPTError('RSA decryption failed')
            return to[:dlen]
    
        def __del__(self):
            if self._rsa is not None:
                RSA_free(self._rsa)
                self._rsa = None

    class AES(object):
        def __init__(self, userkey):
            self._blocksize = len(userkey)
            key = self._key = AES_KEY()
            rv = AES_set_decrypt_key(userkey, len(userkey) * 8, key)
            if rv < 0:
                raise ADEPTError('Failed to initialize AES key')
    
        def decrypt(self, data):
            out = create_string_buffer(len(data))
            iv = ("\x00" * self._blocksize)
            rv = AES_cbc_encrypt(data, out, len(data), self._key, iv, 0)
            if rv == 0:
                raise ADEPTError('AES decryption failed')
            return out.raw

    return (AES, RSA)

def _load_crypto_pycrypto():
    from Crypto.Cipher import AES as _AES
    from Crypto.PublicKey import RSA as _RSA
    from Crypto import Random

    # ASN.1 parsing code from tlslite
    class ASN1Error(Exception):
        pass
    
    class ASN1Parser(object):
        class Parser(object):
            def __init__(self, bytes):
                self.bytes = bytes
                self.index = 0
    
            def get(self, length):
                if self.index + length > len(self.bytes):
                    raise ASN1Error("Error decoding ASN.1")
                x = 0
                for count in range(length):
                    x <<= 8
                    x |= self.bytes[self.index]
                    self.index += 1
                return x
    
            def getFixBytes(self, lengthBytes):
                bytes = self.bytes[self.index : self.index+lengthBytes]
                self.index += lengthBytes
                return bytes
    
            def getVarBytes(self, lengthLength):
                lengthBytes = self.get(lengthLength)
                return self.getFixBytes(lengthBytes)
    
            def getFixList(self, length, lengthList):
                l = [0] * lengthList
                for x in range(lengthList):
                    l[x] = self.get(length)
                return l
    
            def getVarList(self, length, lengthLength):
                lengthList = self.get(lengthLength)
                if lengthList % length != 0:
                    raise ASN1Error("Error decoding ASN.1")
                lengthList = int(lengthList/length)
                l = [0] * lengthList
                for x in range(lengthList):
                    l[x] = self.get(length)
                return l
    
            def startLengthCheck(self, lengthLength):
                self.lengthCheck = self.get(lengthLength)
                self.indexCheck = self.index
    
            def setLengthCheck(self, length):
                self.lengthCheck = length
                self.indexCheck = self.index
    
            def stopLengthCheck(self):
                if (self.index - self.indexCheck) != self.lengthCheck:
                    raise ASN1Error("Error decoding ASN.1")
    
            def atLengthCheck(self):
                if (self.index - self.indexCheck) < self.lengthCheck:
                    return False
                elif (self.index - self.indexCheck) == self.lengthCheck:
                    return True
                else:
                    raise ASN1Error("Error decoding ASN.1")
    
        def __init__(self, bytes):
            p = self.Parser(bytes)
            p.get(1)
            self.length = self._getASN1Length(p)
            self.value = p.getFixBytes(self.length)
    
        def getChild(self, which):
            p = self.Parser(self.value)
            for x in range(which+1):
                markIndex = p.index
                p.get(1)
                length = self._getASN1Length(p)
                p.getFixBytes(length)
            return ASN1Parser(p.bytes[markIndex:p.index])
    
        def _getASN1Length(self, p):
            firstLength = p.get(1)
            if firstLength<=127:
                return firstLength
            else:
                lengthLength = firstLength & 0x7F
                return p.get(lengthLength)

    class AES(object):
        def __init__(self, key):
            iv = Random.new().read(_AES.block_size)
            self._aes = _AES.new(key, _AES.MODE_CBC, iv)

        def decrypt(self, data):
            return self._aes.decrypt(data)

    class RSA(object):
        def __init__(self, der):
            key = ASN1Parser([ord(x) for x in der])
            key = [key.getChild(x).value for x in xrange(1, 4)]
            key = [self.bytesToNumber(v) for v in key]
            self._rsa = _RSA.construct(key)

        def bytesToNumber(self, bytes):
            total = 0L
            for byte in bytes:
                total = (total << 8) + byte
            return total
    
        def decrypt(self, data):
            return self._rsa.decrypt(data)

    return (AES, RSA)

def _load_crypto():
    AES = RSA = None
    for loader in (_load_crypto_libcrypto, _load_crypto_pycrypto):
        try:
            AES, RSA = loader()
            break
        except (ImportError, ADEPTError):
            pass
    return (AES, RSA)
AES, RSA = _load_crypto()

META_NAMES = ('mimetype', 'META-INF/rights.xml', 'META-INF/encryption.xml')
NSMAP = {'adept': 'http://ns.adobe.com/adept',
         'enc': 'http://www.w3.org/2001/04/xmlenc#'}

class ZipInfo(zipfile.ZipInfo):
    def __init__(self, *args, **kwargs):
        if 'compress_type' in kwargs:
            compress_type = kwargs.pop('compress_type')
        super(ZipInfo, self).__init__(*args, **kwargs)
        self.compress_type = compress_type

class Decryptor(object):
    def __init__(self, bookkey, encryption):
        enc = lambda tag: '{%s}%s' % (NSMAP['enc'], tag)
        self._aes = AES(bookkey)
        encryption = etree.fromstring(encryption)
        self._encrypted = encrypted = set()
        expr = './%s/%s/%s' % (enc('EncryptedData'), enc('CipherData'),
                               enc('CipherReference'))
        for elem in encryption.findall(expr):
            path = elem.get('URI', None)
            if path is not None:
                encrypted.add(path)

    def decompress(self, bytes):
        dc = zlib.decompressobj(-15)
        bytes = dc.decompress(bytes)
        ex = dc.decompress('Z') + dc.flush()
        if ex:
            bytes = bytes + ex
        return bytes

    def decrypt(self, path, data):
        if path in self._encrypted:
            data = self._aes.decrypt(data)[16:]
            data = data[:-ord(data[-1])]
            data = self.decompress(data)
        return data

def cli_main(argv=sys.argv):
    progname = os.path.basename(argv[0])
    if AES is None:
        print "%s: This script requires OpenSSL or PyCrypto, which must be" \
              " installed separately.  Read the top-of-script comment for" \
              " details." % (progname,)
        return 1
    if len(argv) != 4:
        print "usage: %s KEYFILE INBOOK OUTBOOK" % (progname,)
        return 1
    keypath, inpath, outpath = argv[1:]
    with open(keypath, 'rb') as f:
        keyder = f.read()
    rsa = RSA(keyder)
    with closing(ZipFile(open(inpath, 'rb'))) as inf:
        namelist = set(inf.namelist())
        if 'META-INF/rights.xml' not in namelist or \
           'META-INF/encryption.xml' not in namelist:
            raise ADEPTError('%s: not an ADEPT EPUB' % (inpath,))
        for name in META_NAMES:
            namelist.remove(name)
        rights = etree.fromstring(inf.read('META-INF/rights.xml'))
        adept = lambda tag: '{%s}%s' % (NSMAP['adept'], tag)
        expr = './/%s' % (adept('encryptedKey'),)
        bookkey = ''.join(rights.findtext(expr))
        bookkey = rsa.decrypt(bookkey.decode('base64'))
        # Padded as per RSAES-PKCS1-v1_5
        if bookkey[-17] != '\x00':
            raise ADEPTError('problem decrypting session key')
        encryption = inf.read('META-INF/encryption.xml')
        decryptor = Decryptor(bookkey[-16:], encryption)
        kwds = dict(compression=ZIP_DEFLATED, allowZip64=False)
        with closing(ZipFile(open(outpath, 'wb'), 'w', **kwds)) as outf:
            zi = ZipInfo('mimetype', compress_type=ZIP_STORED)
            outf.writestr(zi, inf.read('mimetype'))
            for path in namelist:
                data = inf.read(path)
                outf.writestr(path, decryptor.decrypt(path, data))
    return 0

class DecryptionDialog(Tkinter.Frame):
    def __init__(self, root):
        Tkinter.Frame.__init__(self, root, border=5)
        self.status = Tkinter.Label(self, text='Select files for decryption')
        self.status.pack(fill=Tkconstants.X, expand=1)
        body = Tkinter.Frame(self)
        body.pack(fill=Tkconstants.X, expand=1)
        sticky = Tkconstants.E + Tkconstants.W
        body.grid_columnconfigure(1, weight=2)
        Tkinter.Label(body, text='Key file').grid(row=0)
        self.keypath = Tkinter.Entry(body, width=30)
        self.keypath.grid(row=0, column=1, sticky=sticky)
        if os.path.exists('adeptkey.der'):
            self.keypath.insert(0, 'adeptkey.der')
        button = Tkinter.Button(body, text="...", command=self.get_keypath)
        button.grid(row=0, column=2)
        Tkinter.Label(body, text='Input file').grid(row=1)
        self.inpath = Tkinter.Entry(body, width=30)
        self.inpath.grid(row=1, column=1, sticky=sticky)
        button = Tkinter.Button(body, text="...", command=self.get_inpath)
        button.grid(row=1, column=2)
        Tkinter.Label(body, text='Output file').grid(row=2)
        self.outpath = Tkinter.Entry(body, width=30)
        self.outpath.grid(row=2, column=1, sticky=sticky)
        button = Tkinter.Button(body, text="...", command=self.get_outpath)
        button.grid(row=2, column=2)
        buttons = Tkinter.Frame(self)
        buttons.pack()
        botton = Tkinter.Button(
            buttons, text="Decrypt", width=10, command=self.decrypt)
        botton.pack(side=Tkconstants.LEFT)
        Tkinter.Frame(buttons, width=10).pack(side=Tkconstants.LEFT)
        button = Tkinter.Button(
            buttons, text="Quit", width=10, command=self.quit)
        button.pack(side=Tkconstants.RIGHT)

    def get_keypath(self):
        keypath = tkFileDialog.askopenfilename(
            parent=None, title='Select ADEPT key file',
            defaultextension='.der', filetypes=[('DER-encoded files', '.der'),
                                                ('All Files', '.*')])
        if keypath:
            keypath = os.path.normpath(keypath)
            self.keypath.delete(0, Tkconstants.END)
            self.keypath.insert(0, keypath)
        return

    def get_inpath(self):
        inpath = tkFileDialog.askopenfilename(
            parent=None, title='Select ADEPT-encrypted EPUB file to decrypt',
            defaultextension='.epub', filetypes=[('EPUB files', '.epub'),
                                                 ('All files', '.*')])
        if inpath:
            inpath = os.path.normpath(inpath)
            self.inpath.delete(0, Tkconstants.END)
            self.inpath.insert(0, inpath)
        return

    def get_outpath(self):
        outpath = tkFileDialog.asksaveasfilename(
            parent=None, title='Select unencrypted EPUB file to produce',
            defaultextension='.epub', filetypes=[('EPUB files', '.epub'),
                                                 ('All files', '.*')])
        if outpath:
            outpath = os.path.normpath(outpath)
            self.outpath.delete(0, Tkconstants.END)
            self.outpath.insert(0, outpath)
        return

    def decrypt(self):
        keypath = self.keypath.get()
        inpath = self.inpath.get()
        outpath = self.outpath.get()
        if not keypath or not os.path.exists(keypath):
            self.status['text'] = 'Specified key file does not exist'
            return
        if not inpath or not os.path.exists(inpath):
            self.status['text'] = 'Specified input file does not exist'
            return
        if not outpath:
            self.status['text'] = 'Output file not specified'
            return
        if inpath == outpath:
            self.status['text'] = 'Must have different input and output files'
            return
        argv = [sys.argv[0], keypath, inpath, outpath]
        self.status['text'] = 'Decrypting...'
        try:
            cli_main(argv)
        except Exception, e:
            self.status['text'] = 'Error: ' + str(e)
            return
        self.status['text'] = 'File successfully decrypted'

def gui_main():
    root = Tkinter.Tk()
    if AES is None:
        root.withdraw()
        tkMessageBox.showerror(
            "INEPT EPUB Decrypter",
            "This script requires OpenSSL or PyCrypto, which must be"
            " installed separately.  Read the top-of-script comment for"
            " details.")
        return 1
    root.title('INEPT EPUB Decrypter')
    root.resizable(True, False)
    root.minsize(300, 0)
    DecryptionDialog(root).pack(fill=Tkconstants.X, expand=1)
    root.mainloop()
    return 0

if __name__ == '__main__':
    if len(sys.argv) > 1:
        sys.exit(cli_main())
    sys.exit(gui_main())

ineptkey.pyw

#! /usr/bin/python
# -*- coding: utf-8 -*-

# ineptkey.pyw, version 5
# Copyright © 2009-2010 i♥cabbages

# Released under the terms of the GNU General Public Licence, version 3 or
# later.  <http://www.gnu.org/licenses/>

# Windows users: Before running this program, you must first install Python 2.6
#   from <http://www.python.org/download/> and PyCrypto from
#   <http://www.voidspace.org.uk/python/modules.shtml#pycrypto> (make certain
#   to install the version for Python 2.6).  Then save this script file as
#   ineptkey.pyw and double-click on it to run it.  It will create a file named
#   adeptkey.der in the same directory.  This is your ADEPT user key.
#
# Mac OS X users: Save this script file as ineptkey.pyw.  You can run this
#   program from the command line (pythonw ineptkey.pyw) or by double-clicking
#   it when it has been associated with PythonLauncher.  It will create a file
#   named adeptkey.der in the same directory.  This is your ADEPT user key.

# Revision history:
#   1 - Initial release, for Adobe Digital Editions 1.7
#   2 - Better algorithm for finding pLK; improved error handling
#   3 - Rename to INEPT
#   4 - Series of changes by joblack (and others?) --
#   4.1 - quick beta fix for ADE 1.7.2 (anon)
#   4.2 - added old 1.7.1 processing
#   4.3 - better key search
#   4.4 - Make it working on 64-bit Python
#   5 - Clean up and improve 4.x changes;
#       Clean up and merge OS X support by unknown

"""
Retrieve Adobe ADEPT user key.
"""

from __future__ import with_statement

__license__ = 'GPL v3'

import sys
import os
import struct
import Tkinter
import Tkconstants
import tkMessageBox
import traceback

from Crypto import Random

class ADEPTError(Exception):
    pass

if sys.platform.startswith('win'):
    from ctypes import windll, c_char_p, c_wchar_p, c_uint, POINTER, byref, \
        create_unicode_buffer, create_string_buffer, CFUNCTYPE, addressof, \
        string_at, Structure, c_void_p, cast, c_size_t, memmove
    from ctypes.wintypes import LPVOID, DWORD, BOOL
    import _winreg as winreg

    try:
        from Crypto.Cipher import AES
    except ImportError:
        AES = None

    DEVICE_KEY_PATH = r'Software\Adobe\Adept\Device'
    PRIVATE_LICENCE_KEY_PATH = r'Software\Adobe\Adept\Activation'

    MAX_PATH = 255

    kernel32 = windll.kernel32
    advapi32 = windll.advapi32
    crypt32 = windll.crypt32

    def GetSystemDirectory():
        GetSystemDirectoryW = kernel32.GetSystemDirectoryW
        GetSystemDirectoryW.argtypes = [c_wchar_p, c_uint]
        GetSystemDirectoryW.restype = c_uint
        def GetSystemDirectory():
            buffer = create_unicode_buffer(MAX_PATH + 1)
            GetSystemDirectoryW(buffer, len(buffer))
            return buffer.value
        return GetSystemDirectory
    GetSystemDirectory = GetSystemDirectory()

    def GetVolumeSerialNumber():
        GetVolumeInformationW = kernel32.GetVolumeInformationW
        GetVolumeInformationW.argtypes = [c_wchar_p, c_wchar_p, c_uint,
                                          POINTER(c_uint), POINTER(c_uint),
                                          POINTER(c_uint), c_wchar_p, c_uint]
        GetVolumeInformationW.restype = c_uint
        def GetVolumeSerialNumber(path):
            vsn = c_uint(0)
            GetVolumeInformationW(
                path, None, 0, byref(vsn), None, None, None, 0)
            return vsn.value
        return GetVolumeSerialNumber
    GetVolumeSerialNumber = GetVolumeSerialNumber()

    def GetUserName():
        GetUserNameW = advapi32.GetUserNameW
        GetUserNameW.argtypes = [c_wchar_p, POINTER(c_uint)]
        GetUserNameW.restype = c_uint
        def GetUserName():
            buffer = create_unicode_buffer(32)
            size = c_uint(len(buffer))
            while not GetUserNameW(buffer, byref(size)):
                buffer = create_unicode_buffer(len(buffer) * 2)
                size.value = len(buffer)
            return buffer.value.encode('utf-16-le')[::2]
        return GetUserName
    GetUserName = GetUserName()

    PAGE_EXECUTE_READWRITE = 0x40
    MEM_COMMIT  = 0x1000
    MEM_RESERVE = 0x2000

    def VirtualAlloc():
        _VirtualAlloc = kernel32.VirtualAlloc
        _VirtualAlloc.argtypes = [LPVOID, c_size_t, DWORD, DWORD]
        _VirtualAlloc.restype = LPVOID
        def VirtualAlloc(addr, size, alloctype=(MEM_COMMIT | MEM_RESERVE),
                         protect=PAGE_EXECUTE_READWRITE):
            return _VirtualAlloc(addr, size, alloctype, protect)
        return VirtualAlloc
    VirtualAlloc = VirtualAlloc()

    MEM_RELEASE = 0x8000

    def VirtualFree():
        _VirtualFree = kernel32.VirtualFree
        _VirtualFree.argtypes = [LPVOID, c_size_t, DWORD]
        _VirtualFree.restype = BOOL
        def VirtualFree(addr, size=0, freetype=MEM_RELEASE):
            return _VirtualFree(addr, size, freetype)
        return VirtualFree
    VirtualFree = VirtualFree()

    class NativeFunction(object):
        def __init__(self, restype, argtypes, insns):
            self._buf = buf = VirtualAlloc(None, len(insns))
            memmove(buf, insns, len(insns))
            ftype = CFUNCTYPE(restype, *argtypes)
            self._native = ftype(buf)

        def __call__(self, *args):
            return self._native(*args)

        def __del__(self):
            if self._buf is not None:
                VirtualFree(self._buf)
                self._buf = None

    if struct.calcsize("P") == 4:
        CPUID0_INSNS = (
            "\x53"             # push   %ebx
            "\x31\xc0"         # xor    %eax,%eax
            "\x0f\xa2"         # cpuid
            "\x8b\x44\x24\x08" # mov    0x8(%esp),%eax
            "\x89\x18"         # mov    %ebx,0x0(%eax)
            "\x89\x50\x04"     # mov    %edx,0x4(%eax)
            "\x89\x48\x08"     # mov    %ecx,0x8(%eax)
            "\x5b"             # pop    %ebx
            "\xc3"             # ret
        )
        CPUID1_INSNS = (
            "\x53"             # push   %ebx
            "\x31\xc0"         # xor    %eax,%eax
            "\x40"             # inc    %eax
            "\x0f\xa2"         # cpuid
            "\x5b"             # pop    %ebx
            "\xc3"             # ret
        )
    else:
        CPUID0_INSNS = (
            "\x49\x89\xd8"     # mov    %rbx,%r8
            "\x49\x89\xc9"     # mov    %rcx,%r9
            "\x48\x31\xc0"     # xor    %rax,%rax
            "\x0f\xa2"         # cpuid
            "\x4c\x89\xc8"     # mov    %r9,%rax
            "\x89\x18"         # mov    %ebx,0x0(%rax)
            "\x89\x50\x04"     # mov    %edx,0x4(%rax)
            "\x89\x48\x08"     # mov    %ecx,0x8(%rax)
            "\x4c\x89\xc3"     # mov    %r8,%rbx
            "\xc3"             # retq
        )
        CPUID1_INSNS = (
            "\x53"             # push   %rbx
            "\x48\x31\xc0"     # xor    %rax,%rax
            "\x48\xff\xc0"     # inc    %rax
            "\x0f\xa2"         # cpuid
            "\x5b"             # pop    %rbx
            "\xc3"             # retq
        )

    def cpuid0():
        _cpuid0 = NativeFunction(None, [c_char_p], CPUID0_INSNS)
        buf = create_string_buffer(12)
        def cpuid0():
            _cpuid0(buf)
            return buf.raw
        return cpuid0
    cpuid0 = cpuid0()

    cpuid1 = NativeFunction(c_uint, [], CPUID1_INSNS)

    class DataBlob(Structure):
        _fields_ = [('cbData', c_uint),
                    ('pbData', c_void_p)]
    DataBlob_p = POINTER(DataBlob)

    def CryptUnprotectData():
        _CryptUnprotectData = crypt32.CryptUnprotectData
        _CryptUnprotectData.argtypes = [DataBlob_p, c_wchar_p, DataBlob_p,
                                       c_void_p, c_void_p, c_uint, DataBlob_p]
        _CryptUnprotectData.restype = c_uint
        def CryptUnprotectData(indata, entropy):
            indatab = create_string_buffer(indata)
            indata = DataBlob(len(indata), cast(indatab, c_void_p))
            entropyb = create_string_buffer(entropy)
            entropy = DataBlob(len(entropy), cast(entropyb, c_void_p))
            outdata = DataBlob()
            if not _CryptUnprotectData(byref(indata), None, byref(entropy),
                                       None, None, 0, byref(outdata)):
                raise ADEPTError("Failed to decrypt user key key (sic)")
            return string_at(outdata.pbData, outdata.cbData)
        return CryptUnprotectData
    CryptUnprotectData = CryptUnprotectData()

    def retrieve_key(keypath):
        if AES is None:
            tkMessageBox.showerror(
                "ADEPT Key",
                "This script requires PyCrypto, which must be installed "
                "separately.  Read the top-of-script comment for details.")
            return False
        root = GetSystemDirectory().split('\\')[0] + '\\'
        serial = GetVolumeSerialNumber(root)
        vendor = cpuid0()
        signature = struct.pack('>I', cpuid1())[1:]
        user = GetUserName()
        entropy = struct.pack('>I12s3s13s', serial, vendor, signature, user)
        cuser = winreg.HKEY_CURRENT_USER
        try:
            regkey = winreg.OpenKey(cuser, DEVICE_KEY_PATH)
        except WindowsError:
            raise ADEPTError("Adobe Digital Editions not activated")
        device = winreg.QueryValueEx(regkey, 'key')[0]
        keykey = CryptUnprotectData(device, entropy)
        userkey = None
        try:
            plkroot = winreg.OpenKey(cuser, PRIVATE_LICENCE_KEY_PATH)
        except WindowsError:
            raise ADEPTError("Could not locate ADE activation")
        for i in xrange(0, 16):
            try:
                plkparent = winreg.OpenKey(plkroot, "%04d" % (i,))
            except WindowsError:
                break
            ktype = winreg.QueryValueEx(plkparent, None)[0]
            if ktype != 'credentials':
                continue
            for j in xrange(0, 16):
                try:
                    plkkey = winreg.OpenKey(plkparent, "%04d" % (j,))
                except WindowsError:
                    break
                ktype = winreg.QueryValueEx(plkkey, None)[0]
                if ktype != 'privateLicenseKey':
                    continue
                userkey = winreg.QueryValueEx(plkkey, 'value')[0]
                break
            if userkey is not None:
                break
        if userkey is None:
            raise ADEPTError('Could not locate privateLicenseKey')
        userkey = userkey.decode('base64')
        iv = Random.new().read(AES.block_size)
        userkey = AES.new(keykey, AES.MODE_CBC, iv).decrypt(userkey)
        userkey = userkey[26:-ord(userkey[-1])]
        with open(keypath, 'wb') as f:
            f.write(userkey)
        return True

elif sys.platform.startswith('darwin'):
    import xml.etree.ElementTree as etree
    import Carbon.File
    import Carbon.Folder
    import Carbon.Folders
    import MacOS

    ACTIVATION_PATH = 'Adobe/Digital Editions/activation.dat'
    NSMAP = {'adept': 'http://ns.adobe.com/adept',
             'enc': 'http://www.w3.org/2001/04/xmlenc#'}

    def find_folder(domain, dtype):
        try:
            fsref = Carbon.Folder.FSFindFolder(domain, dtype, False)
            return Carbon.File.pathname(fsref)
        except MacOS.Error:
            return None

    def find_app_support_file(subpath):
        dtype = Carbon.Folders.kApplicationSupportFolderType
        for domain in Carbon.Folders.kUserDomain, Carbon.Folders.kLocalDomain:
            path = find_folder(domain, dtype)
            if path is None:
                continue
            path = os.path.join(path, subpath)
            if os.path.isfile(path):
                return path
        return None

    def retrieve_key(keypath):
        actpath = find_app_support_file(ACTIVATION_PATH)
        if actpath is None:
            raise ADEPTError("Could not locate ADE activation")
        tree = etree.parse(actpath)
        adept = lambda tag: '{%s}%s' % (NSMAP['adept'], tag)
        expr = '//%s/%s' % (adept('credentials'), adept('privateLicenseKey'))
        userkey = tree.findtext(expr)
        userkey = userkey.decode('base64')
        userkey = userkey[26:]
        with open(keypath, 'wb') as f:
            f.write(userkey)
        return True

elif sys.platform.startswith('cygwin'):
    def retrieve_key(keypath):
        tkMessageBox.showerror(
            "ADEPT Key",
            "This script requires a Windows-native Python, and cannot be run "
            "under Cygwin.  Please install a Windows-native Python and/or "
            "check your file associations.")
        return False

else:
    def retrieve_key(keypath):
        tkMessageBox.showerror(
            "ADEPT Key",
            "This script only supports Windows and Mac OS X.  For Linux "
            "you should be able to run ADE and this script under Wine (with "
            "an appropriate version of Windows Python installed).")
        return False

class ExceptionDialog(Tkinter.Frame):
    def __init__(self, root, text):
        Tkinter.Frame.__init__(self, root, border=5)
        label = Tkinter.Label(self, text="Unexpected error:",
                              anchor=Tkconstants.W, justify=Tkconstants.LEFT)
        label.pack(fill=Tkconstants.X, expand=0)
        self.text = Tkinter.Text(self)
        self.text.pack(fill=Tkconstants.BOTH, expand=1)
        self.text.insert(Tkconstants.END, text)

def main(argv=sys.argv):
    root = Tkinter.Tk()
    root.withdraw()
    progname = os.path.basename(argv[0])
    keypath = 'adeptkey.der'
    success = False
    try:
        success = retrieve_key(keypath)
    except ADEPTError, e:
        tkMessageBox.showerror("ADEPT Key", "Error: " + str(e))
    except Exception:
        root.wm_state('normal')
        root.title('ADEPT Key')
        text = traceback.format_exc()
        ExceptionDialog(root, text).pack(fill=Tkconstants.BOTH, expand=1)
        root.mainloop()
    if not success:
        return 1
    tkMessageBox.showinfo(
        "ADEPT Key", "Key successfully retrieved to %s" % (keypath))
    return 0

if __name__ == '__main__':
    sys.exit(main())