DeDRM_tools/DeDRM_calibre_plugin/DeDRM_plugin/kindlekey.py

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

from __future__ import with_statement

# kindlekey.py
# Copyright © 2010-2015 by some_updates, Apprentice Alf and Apprentice Harper

# Revision history:
#  1.0   - Kindle info file decryption, extracted from k4mobidedrm, etc.
#  1.1   - Added Tkinter to match adobekey.py
#  1.2   - Fixed testing of successful retrieval on Mac
#  1.3   - Added getkey interface for Windows DeDRM application
#          Simplified some of the Kindle for Mac code.
#  1.4   - Remove dependency on alfcrypto
#  1.5   - moved unicode_argv call inside main for Windows DeDRM compatibility
#  1.6   - Fixed a problem getting the disk serial numbers
#  1.7   - Work if TkInter is missing
#  1.8   - Fixes for Kindle for Mac, and non-ascii in Windows user names
#  1.9   - Fixes for Unicode in Windows user names
#  2.0   - Added comments and extra fix for non-ascii Windows user names


"""
Retrieve Kindle for PC/Mac user key.
"""

__license__ = 'GPL v3'
__version__ = '1.9'

import sys, os, re
from struct import pack, unpack, unpack_from
import json
import getopt

# Routines common to Mac and PC

# Wrap a stream so that output gets flushed immediately
# and also make sure that any unicode strings get
# encoded using "replace" before writing them.
class SafeUnbuffered:
    def __init__(self, stream):
        self.stream = stream
        self.encoding = stream.encoding
        if self.encoding == None:
            self.encoding = "utf-8"
    def write(self, data):
        if isinstance(data,unicode):
            data = data.encode(self.encoding,"replace")
        self.stream.write(data)
        self.stream.flush()
    def __getattr__(self, attr):
        return getattr(self.stream, attr)

try:
    from calibre.constants import iswindows, isosx
except:
    iswindows = sys.platform.startswith('win')
    isosx = sys.platform.startswith('darwin')

def unicode_argv():
    if iswindows:
        # Uses shell32.GetCommandLineArgvW to get sys.argv as a list of Unicode
        # strings.

        # Versions 2.x of Python don't support Unicode in sys.argv on
        # Windows, with the underlying Windows API instead replacing multi-byte
        # characters with '?'.  So use shell32.GetCommandLineArgvW to get sys.argv
        # as a list of Unicode strings and encode them as utf-8

        from ctypes import POINTER, byref, cdll, c_int, windll
        from ctypes.wintypes import LPCWSTR, LPWSTR

        GetCommandLineW = cdll.kernel32.GetCommandLineW
        GetCommandLineW.argtypes = []
        GetCommandLineW.restype = LPCWSTR

        CommandLineToArgvW = windll.shell32.CommandLineToArgvW
        CommandLineToArgvW.argtypes = [LPCWSTR, POINTER(c_int)]
        CommandLineToArgvW.restype = POINTER(LPWSTR)

        cmd = GetCommandLineW()
        argc = c_int(0)
        argv = CommandLineToArgvW(cmd, byref(argc))
        if argc.value > 0:
            # Remove Python executable and commands if present
            start = argc.value - len(sys.argv)
            return [argv[i] for i in
                    xrange(start, argc.value)]
        # if we don't have any arguments at all, just pass back script name
        # this should never happen
        return [u"kindlekey.py"]
    else:
        argvencoding = sys.stdin.encoding
        if argvencoding == None:
            argvencoding = "utf-8"
        return [arg if (type(arg) == unicode) else unicode(arg,argvencoding) for arg in sys.argv]

class DrmException(Exception):
    pass

# crypto digestroutines
import hashlib

def MD5(message):
    ctx = hashlib.md5()
    ctx.update(message)
    return ctx.digest()

def SHA1(message):
    ctx = hashlib.sha1()
    ctx.update(message)
    return ctx.digest()

def SHA256(message):
    ctx = hashlib.sha256()
    ctx.update(message)
    return ctx.digest()

# For K4M/PC 1.6.X and later
# generate table of prime number less than or equal to int n
def primes(n):
    if n==2: return [2]
    elif n<2: return []
    s=range(3,n+1,2)
    mroot = n ** 0.5
    half=(n+1)/2-1
    i=0
    m=3
    while m <= mroot:
        if s[i]:
            j=(m*m-3)/2
            s[j]=0
            while j<half:
                s[j]=0
                j+=m
        i=i+1
        m=2*i+3
    return [2]+[x for x in s if x]

# Encode the bytes in data with the characters in map
def encode(data, map):
    result = ''
    for char in data:
        value = ord(char)
        Q = (value ^ 0x80) // len(map)
        R = value % len(map)
        result += map[Q]
        result += map[R]
    return result

# Hash the bytes in data and then encode the digest with the characters in map
def encodeHash(data,map):
    return encode(MD5(data),map)

# Decode the string in data with the characters in map. Returns the decoded bytes
def decode(data,map):
    result = ''
    for i in range (0,len(data)-1,2):
        high = map.find(data[i])
        low = map.find(data[i+1])
        if (high == -1) or (low == -1) :
            break
        value = (((high * len(map)) ^ 0x80) & 0xFF) + low
        result += pack('B',value)
    return result

# Routines unique to Mac and PC
if iswindows:
    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

    import _winreg as winreg
    MAX_PATH = 255
    kernel32 = windll.kernel32
    advapi32 = windll.advapi32
    crypt32 = windll.crypt32

    try:
        # try to get fast routines from alfcrypto
        from alfcrypto import AES_CBC, KeyIVGen
    except:
        # alfcrypto not available, so use python implementations
        """
            Routines for doing AES CBC in one file

            Modified by some_updates to extract
            and combine only those parts needed for AES CBC
            into one simple to add python file

            Original Version
            Copyright (c) 2002 by Paul A. Lambert
            Under:
            CryptoPy Artisitic License Version 1.0
            See the wonderful pure python package cryptopy-1.2.5
            and read its LICENSE.txt for complete license details.
        """

        class CryptoError(Exception):
            """ Base class for crypto exceptions """
            def __init__(self,errorMessage='Error!'):
                self.message = errorMessage
            def __str__(self):
                return self.message

        class InitCryptoError(CryptoError):
            """ Crypto errors during algorithm initialization """
        class BadKeySizeError(InitCryptoError):
            """ Bad key size error """
        class EncryptError(CryptoError):
            """ Error in encryption processing """
        class DecryptError(CryptoError):
            """ Error in decryption processing """
        class DecryptNotBlockAlignedError(DecryptError):
            """ Error in decryption processing """

        def xorS(a,b):
            """ XOR two strings """
            assert len(a)==len(b)
            x = []
            for i in range(len(a)):
                x.append( chr(ord(a[i])^ord(b[i])))
            return ''.join(x)

        def xor(a,b):
            """ XOR two strings """
            x = []
            for i in range(min(len(a),len(b))):
                x.append( chr(ord(a[i])^ord(b[i])))
            return ''.join(x)

        """
            Base 'BlockCipher' and Pad classes for cipher instances.
            BlockCipher supports automatic padding and type conversion. The BlockCipher
            class was written to make the actual algorithm code more readable and
            not for performance.
        """

        class BlockCipher:
            """ Block ciphers """
            def __init__(self):
                self.reset()

            def reset(self):
                self.resetEncrypt()
                self.resetDecrypt()
            def resetEncrypt(self):
                self.encryptBlockCount = 0
                self.bytesToEncrypt = ''
            def resetDecrypt(self):
                self.decryptBlockCount = 0
                self.bytesToDecrypt = ''

            def encrypt(self, plainText, more = None):
                """ Encrypt a string and return a binary string """
                self.bytesToEncrypt += plainText  # append plainText to any bytes from prior encrypt
                numBlocks, numExtraBytes = divmod(len(self.bytesToEncrypt), self.blockSize)
                cipherText = ''
                for i in range(numBlocks):
                    bStart = i*self.blockSize
                    ctBlock = self.encryptBlock(self.bytesToEncrypt[bStart:bStart+self.blockSize])
                    self.encryptBlockCount += 1
                    cipherText += ctBlock
                if numExtraBytes > 0:        # save any bytes that are not block aligned
                    self.bytesToEncrypt = self.bytesToEncrypt[-numExtraBytes:]
                else:
                    self.bytesToEncrypt = ''

                if more == None:   # no more data expected from caller
                    finalBytes = self.padding.addPad(self.bytesToEncrypt,self.blockSize)
                    if len(finalBytes) > 0:
                        ctBlock = self.encryptBlock(finalBytes)
                        self.encryptBlockCount += 1
                        cipherText += ctBlock
                    self.resetEncrypt()
                return cipherText

            def decrypt(self, cipherText, more = None):
                """ Decrypt a string and return a string """
                self.bytesToDecrypt += cipherText  # append to any bytes from prior decrypt

                numBlocks, numExtraBytes = divmod(len(self.bytesToDecrypt), self.blockSize)
                if more == None:  # no more calls to decrypt, should have all the data
                    if numExtraBytes  != 0:
                        raise DecryptNotBlockAlignedError, 'Data not block aligned on decrypt'

                # hold back some bytes in case last decrypt has zero len
                if (more != None) and (numExtraBytes == 0) and (numBlocks >0) :
                    numBlocks -= 1
                    numExtraBytes = self.blockSize

                plainText = ''
                for i in range(numBlocks):
                    bStart = i*self.blockSize
                    ptBlock = self.decryptBlock(self.bytesToDecrypt[bStart : bStart+self.blockSize])
                    self.decryptBlockCount += 1
                    plainText += ptBlock

                if numExtraBytes > 0:        # save any bytes that are not block aligned
                    self.bytesToEncrypt = self.bytesToEncrypt[-numExtraBytes:]
                else:
                    self.bytesToEncrypt = ''

                if more == None:         # last decrypt remove padding
                    plainText = self.padding.removePad(plainText, self.blockSize)
                    self.resetDecrypt()
                return plainText


        class Pad:
            def __init__(self):
                pass              # eventually could put in calculation of min and max size extension

        class padWithPadLen(Pad):
            """ Pad a binary string with the length of the padding """

            def addPad(self, extraBytes, blockSize):
                """ Add padding to a binary string to make it an even multiple
                    of the block size """
                blocks, numExtraBytes = divmod(len(extraBytes), blockSize)
                padLength = blockSize - numExtraBytes
                return extraBytes + padLength*chr(padLength)

            def removePad(self, paddedBinaryString, blockSize):
                """ Remove padding from a binary string """
                if not(0<len(paddedBinaryString)):
                    raise DecryptNotBlockAlignedError, 'Expected More Data'
                return paddedBinaryString[:-ord(paddedBinaryString[-1])]

        class noPadding(Pad):
            """ No padding. Use this to get ECB behavior from encrypt/decrypt """

            def addPad(self, extraBytes, blockSize):
                """ Add no padding """
                return extraBytes

            def removePad(self, paddedBinaryString, blockSize):
                """ Remove no padding """
                return paddedBinaryString

        """
            Rijndael encryption algorithm
            This byte oriented implementation is intended to closely
            match FIPS specification for readability.  It is not implemented
            for performance.
        """

        class Rijndael(BlockCipher):
            """ Rijndael encryption algorithm """
            def __init__(self, key = None, padding = padWithPadLen(), keySize=16, blockSize=16 ):
                self.name       = 'RIJNDAEL'
                self.keySize    = keySize
                self.strength   = keySize*8
                self.blockSize  = blockSize  # blockSize is in bytes
                self.padding    = padding    # change default to noPadding() to get normal ECB behavior

                assert( keySize%4==0 and NrTable[4].has_key(keySize/4)),'key size must be 16,20,24,29 or 32 bytes'
                assert( blockSize%4==0 and NrTable.has_key(blockSize/4)), 'block size must be 16,20,24,29 or 32 bytes'

                self.Nb = self.blockSize/4          # Nb is number of columns of 32 bit words
                self.Nk = keySize/4                 # Nk is the key length in 32-bit words
                self.Nr = NrTable[self.Nb][self.Nk] # The number of rounds (Nr) is a function of
                                                    # the block (Nb) and key (Nk) sizes.
                if key != None:
                    self.setKey(key)

            def setKey(self, key):
                """ Set a key and generate the expanded key """
                assert( len(key) == (self.Nk*4) ), 'Key length must be same as keySize parameter'
                self.__expandedKey = keyExpansion(self, key)
                self.reset()                   # BlockCipher.reset()

            def encryptBlock(self, plainTextBlock):
                """ Encrypt a block, plainTextBlock must be a array of bytes [Nb by 4] """
                self.state = self._toBlock(plainTextBlock)
                AddRoundKey(self, self.__expandedKey[0:self.Nb])
                for round in range(1,self.Nr):          #for round = 1 step 1 to Nr
                    SubBytes(self)
                    ShiftRows(self)
                    MixColumns(self)
                    AddRoundKey(self, self.__expandedKey[round*self.Nb:(round+1)*self.Nb])
                SubBytes(self)
                ShiftRows(self)
                AddRoundKey(self, self.__expandedKey[self.Nr*self.Nb:(self.Nr+1)*self.Nb])
                return self._toBString(self.state)


            def decryptBlock(self, encryptedBlock):
                """ decrypt a block (array of bytes) """
                self.state = self._toBlock(encryptedBlock)
                AddRoundKey(self, self.__expandedKey[self.Nr*self.Nb:(self.Nr+1)*self.Nb])
                for round in range(self.Nr-1,0,-1):
                    InvShiftRows(self)
                    InvSubBytes(self)
                    AddRoundKey(self, self.__expandedKey[round*self.Nb:(round+1)*self.Nb])
                    InvMixColumns(self)
                InvShiftRows(self)
                InvSubBytes(self)
                AddRoundKey(self, self.__expandedKey[0:self.Nb])
                return self._toBString(self.state)

            def _toBlock(self, bs):
                """ Convert binary string to array of bytes, state[col][row]"""
                assert ( len(bs) == 4*self.Nb ), 'Rijndarl blocks must be of size blockSize'
                return [[ord(bs[4*i]),ord(bs[4*i+1]),ord(bs[4*i+2]),ord(bs[4*i+3])] for i in range(self.Nb)]

            def _toBString(self, block):
                """ Convert block (array of bytes) to binary string """
                l = []
                for col in block:
                    for rowElement in col:
                        l.append(chr(rowElement))
                return ''.join(l)
        #-------------------------------------
        """    Number of rounds Nr = NrTable[Nb][Nk]

                    Nb  Nk=4   Nk=5   Nk=6   Nk=7   Nk=8
                    -------------------------------------   """
        NrTable =  {4: {4:10,  5:11,  6:12,  7:13,  8:14},
                    5: {4:11,  5:11,  6:12,  7:13,  8:14},
                    6: {4:12,  5:12,  6:12,  7:13,  8:14},
                    7: {4:13,  5:13,  6:13,  7:13,  8:14},
                    8: {4:14,  5:14,  6:14,  7:14,  8:14}}
        #-------------------------------------
        def keyExpansion(algInstance, keyString):
            """ Expand a string of size keySize into a larger array """
            Nk, Nb, Nr = algInstance.Nk, algInstance.Nb, algInstance.Nr # for readability
            key = [ord(byte) for byte in keyString]  # convert string to list
            w = [[key[4*i],key[4*i+1],key[4*i+2],key[4*i+3]] for i in range(Nk)]
            for i in range(Nk,Nb*(Nr+1)):
                temp = w[i-1]        # a four byte column
                if (i%Nk) == 0 :
                    temp     = temp[1:]+[temp[0]]  # RotWord(temp)
                    temp     = [ Sbox[byte] for byte in temp ]
                    temp[0] ^= Rcon[i/Nk]
                elif Nk > 6 and  i%Nk == 4 :
                    temp     = [ Sbox[byte] for byte in temp ]  # SubWord(temp)
                w.append( [ w[i-Nk][byte]^temp[byte] for byte in range(4) ] )
            return w

        Rcon = (0,0x01,0x02,0x04,0x08,0x10,0x20,0x40,0x80,0x1b,0x36,     # note extra '0' !!!
                0x6c,0xd8,0xab,0x4d,0x9a,0x2f,0x5e,0xbc,0x63,0xc6,
                0x97,0x35,0x6a,0xd4,0xb3,0x7d,0xfa,0xef,0xc5,0x91)

        #-------------------------------------
        def AddRoundKey(algInstance, keyBlock):
            """ XOR the algorithm state with a block of key material """
            for column in range(algInstance.Nb):
                for row in range(4):
                    algInstance.state[column][row] ^= keyBlock[column][row]
        #-------------------------------------

        def SubBytes(algInstance):
            for column in range(algInstance.Nb):
                for row in range(4):
                    algInstance.state[column][row] = Sbox[algInstance.state[column][row]]

        def InvSubBytes(algInstance):
            for column in range(algInstance.Nb):
                for row in range(4):
                    algInstance.state[column][row] = InvSbox[algInstance.state[column][row]]

        Sbox =    (0x63,0x7c,0x77,0x7b,0xf2,0x6b,0x6f,0xc5,
                   0x30,0x01,0x67,0x2b,0xfe,0xd7,0xab,0x76,
                   0xca,0x82,0xc9,0x7d,0xfa,0x59,0x47,0xf0,
                   0xad,0xd4,0xa2,0xaf,0x9c,0xa4,0x72,0xc0,
                   0xb7,0xfd,0x93,0x26,0x36,0x3f,0xf7,0xcc,
                   0x34,0xa5,0xe5,0xf1,0x71,0xd8,0x31,0x15,
                   0x04,0xc7,0x23,0xc3,0x18,0x96,0x05,0x9a,
                   0x07,0x12,0x80,0xe2,0xeb,0x27,0xb2,0x75,
                   0x09,0x83,0x2c,0x1a,0x1b,0x6e,0x5a,0xa0,
                   0x52,0x3b,0xd6,0xb3,0x29,0xe3,0x2f,0x84,
                   0x53,0xd1,0x00,0xed,0x20,0xfc,0xb1,0x5b,
                   0x6a,0xcb,0xbe,0x39,0x4a,0x4c,0x58,0xcf,
                   0xd0,0xef,0xaa,0xfb,0x43,0x4d,0x33,0x85,
                   0x45,0xf9,0x02,0x7f,0x50,0x3c,0x9f,0xa8,
                   0x51,0xa3,0x40,0x8f,0x92,0x9d,0x38,0xf5,
                   0xbc,0xb6,0xda,0x21,0x10,0xff,0xf3,0xd2,
                   0xcd,0x0c,0x13,0xec,0x5f,0x97,0x44,0x17,
                   0xc4,0xa7,0x7e,0x3d,0x64,0x5d,0x19,0x73,
                   0x60,0x81,0x4f,0xdc,0x22,0x2a,0x90,0x88,
                   0x46,0xee,0xb8,0x14,0xde,0x5e,0x0b,0xdb,
                   0xe0,0x32,0x3a,0x0a,0x49,0x06,0x24,0x5c,
                   0xc2,0xd3,0xac,0x62,0x91,0x95,0xe4,0x79,
                   0xe7,0xc8,0x37,0x6d,0x8d,0xd5,0x4e,0xa9,
                   0x6c,0x56,0xf4,0xea,0x65,0x7a,0xae,0x08,
                   0xba,0x78,0x25,0x2e,0x1c,0xa6,0xb4,0xc6,
                   0xe8,0xdd,0x74,0x1f,0x4b,0xbd,0x8b,0x8a,
                   0x70,0x3e,0xb5,0x66,0x48,0x03,0xf6,0x0e,
                   0x61,0x35,0x57,0xb9,0x86,0xc1,0x1d,0x9e,
                   0xe1,0xf8,0x98,0x11,0x69,0xd9,0x8e,0x94,
                   0x9b,0x1e,0x87,0xe9,0xce,0x55,0x28,0xdf,
                   0x8c,0xa1,0x89,0x0d,0xbf,0xe6,0x42,0x68,
                   0x41,0x99,0x2d,0x0f,0xb0,0x54,0xbb,0x16)

        InvSbox = (0x52,0x09,0x6a,0xd5,0x30,0x36,0xa5,0x38,
                   0xbf,0x40,0xa3,0x9e,0x81,0xf3,0xd7,0xfb,
                   0x7c,0xe3,0x39,0x82,0x9b,0x2f,0xff,0x87,
                   0x34,0x8e,0x43,0x44,0xc4,0xde,0xe9,0xcb,
                   0x54,0x7b,0x94,0x32,0xa6,0xc2,0x23,0x3d,
                   0xee,0x4c,0x95,0x0b,0x42,0xfa,0xc3,0x4e,
                   0x08,0x2e,0xa1,0x66,0x28,0xd9,0x24,0xb2,
                   0x76,0x5b,0xa2,0x49,0x6d,0x8b,0xd1,0x25,
                   0x72,0xf8,0xf6,0x64,0x86,0x68,0x98,0x16,
                   0xd4,0xa4,0x5c,0xcc,0x5d,0x65,0xb6,0x92,
                   0x6c,0x70,0x48,0x50,0xfd,0xed,0xb9,0xda,
                   0x5e,0x15,0x46,0x57,0xa7,0x8d,0x9d,0x84,
                   0x90,0xd8,0xab,0x00,0x8c,0xbc,0xd3,0x0a,
                   0xf7,0xe4,0x58,0x05,0xb8,0xb3,0x45,0x06,
                   0xd0,0x2c,0x1e,0x8f,0xca,0x3f,0x0f,0x02,
                   0xc1,0xaf,0xbd,0x03,0x01,0x13,0x8a,0x6b,
                   0x3a,0x91,0x11,0x41,0x4f,0x67,0xdc,0xea,
                   0x97,0xf2,0xcf,0xce,0xf0,0xb4,0xe6,0x73,
                   0x96,0xac,0x74,0x22,0xe7,0xad,0x35,0x85,
                   0xe2,0xf9,0x37,0xe8,0x1c,0x75,0xdf,0x6e,
                   0x47,0xf1,0x1a,0x71,0x1d,0x29,0xc5,0x89,
                   0x6f,0xb7,0x62,0x0e,0xaa,0x18,0xbe,0x1b,
                   0xfc,0x56,0x3e,0x4b,0xc6,0xd2,0x79,0x20,
                   0x9a,0xdb,0xc0,0xfe,0x78,0xcd,0x5a,0xf4,
                   0x1f,0xdd,0xa8,0x33,0x88,0x07,0xc7,0x31,
                   0xb1,0x12,0x10,0x59,0x27,0x80,0xec,0x5f,
                   0x60,0x51,0x7f,0xa9,0x19,0xb5,0x4a,0x0d,
                   0x2d,0xe5,0x7a,0x9f,0x93,0xc9,0x9c,0xef,
                   0xa0,0xe0,0x3b,0x4d,0xae,0x2a,0xf5,0xb0,
                   0xc8,0xeb,0xbb,0x3c,0x83,0x53,0x99,0x61,
                   0x17,0x2b,0x04,0x7e,0xba,0x77,0xd6,0x26,
                   0xe1,0x69,0x14,0x63,0x55,0x21,0x0c,0x7d)

        #-------------------------------------
        """ For each block size (Nb), the ShiftRow operation shifts row i
            by the amount Ci.  Note that row 0 is not shifted.
                         Nb      C1 C2 C3
                       -------------------  """
        shiftOffset  = { 4 : ( 0, 1, 2, 3),
                         5 : ( 0, 1, 2, 3),
                         6 : ( 0, 1, 2, 3),
                         7 : ( 0, 1, 2, 4),
                         8 : ( 0, 1, 3, 4) }
        def ShiftRows(algInstance):
            tmp = [0]*algInstance.Nb   # list of size Nb
            for r in range(1,4):       # row 0 reamains unchanged and can be skipped
                for c in range(algInstance.Nb):
                    tmp[c] = algInstance.state[(c+shiftOffset[algInstance.Nb][r]) % algInstance.Nb][r]
                for c in range(algInstance.Nb):
                    algInstance.state[c][r] = tmp[c]
        def InvShiftRows(algInstance):
            tmp = [0]*algInstance.Nb   # list of size Nb
            for r in range(1,4):       # row 0 reamains unchanged and can be skipped
                for c in range(algInstance.Nb):
                    tmp[c] = algInstance.state[(c+algInstance.Nb-shiftOffset[algInstance.Nb][r]) % algInstance.Nb][r]
                for c in range(algInstance.Nb):
                    algInstance.state[c][r] = tmp[c]
        #-------------------------------------
        def MixColumns(a):
            Sprime = [0,0,0,0]
            for j in range(a.Nb):    # for each column
                Sprime[0] = mul(2,a.state[j][0])^mul(3,a.state[j][1])^mul(1,a.state[j][2])^mul(1,a.state[j][3])
                Sprime[1] = mul(1,a.state[j][0])^mul(2,a.state[j][1])^mul(3,a.state[j][2])^mul(1,a.state[j][3])
                Sprime[2] = mul(1,a.state[j][0])^mul(1,a.state[j][1])^mul(2,a.state[j][2])^mul(3,a.state[j][3])
                Sprime[3] = mul(3,a.state[j][0])^mul(1,a.state[j][1])^mul(1,a.state[j][2])^mul(2,a.state[j][3])
                for i in range(4):
                    a.state[j][i] = Sprime[i]

        def InvMixColumns(a):
            """ Mix the four bytes of every column in a linear way
                This is the opposite operation of Mixcolumn """
            Sprime = [0,0,0,0]
            for j in range(a.Nb):    # for each column
                Sprime[0] = mul(0x0E,a.state[j][0])^mul(0x0B,a.state[j][1])^mul(0x0D,a.state[j][2])^mul(0x09,a.state[j][3])
                Sprime[1] = mul(0x09,a.state[j][0])^mul(0x0E,a.state[j][1])^mul(0x0B,a.state[j][2])^mul(0x0D,a.state[j][3])
                Sprime[2] = mul(0x0D,a.state[j][0])^mul(0x09,a.state[j][1])^mul(0x0E,a.state[j][2])^mul(0x0B,a.state[j][3])
                Sprime[3] = mul(0x0B,a.state[j][0])^mul(0x0D,a.state[j][1])^mul(0x09,a.state[j][2])^mul(0x0E,a.state[j][3])
                for i in range(4):
                    a.state[j][i] = Sprime[i]

        #-------------------------------------
        def mul(a, b):
            """ Multiply two elements of GF(2^m)
                needed for MixColumn and InvMixColumn """
            if (a !=0 and  b!=0):
                return Alogtable[(Logtable[a] + Logtable[b])%255]
            else:
                return 0

        Logtable = ( 0,   0,  25,   1,  50,   2,  26, 198,  75, 199,  27, 104,  51, 238, 223,   3,
                   100,   4, 224,  14,  52, 141, 129, 239,  76, 113,   8, 200, 248, 105,  28, 193,
                   125, 194,  29, 181, 249, 185,  39, 106,  77, 228, 166, 114, 154, 201,   9, 120,
                   101,  47, 138,   5,  33,  15, 225,  36,  18, 240, 130,  69,  53, 147, 218, 142,
                   150, 143, 219, 189,  54, 208, 206, 148,  19,  92, 210, 241,  64,  70, 131,  56,
                   102, 221, 253,  48, 191,   6, 139,  98, 179,  37, 226, 152,  34, 136, 145,  16,
                   126, 110,  72, 195, 163, 182,  30,  66,  58, 107,  40,  84, 250, 133,  61, 186,
                    43, 121,  10,  21, 155, 159,  94, 202,  78, 212, 172, 229, 243, 115, 167,  87,
                   175,  88, 168,  80, 244, 234, 214, 116,  79, 174, 233, 213, 231, 230, 173, 232,
                    44, 215, 117, 122, 235,  22,  11, 245,  89, 203,  95, 176, 156, 169,  81, 160,
                   127,  12, 246, 111,  23, 196,  73, 236, 216,  67,  31,  45, 164, 118, 123, 183,
                   204, 187,  62,  90, 251,  96, 177, 134,  59,  82, 161, 108, 170,  85,  41, 157,
                   151, 178, 135, 144,  97, 190, 220, 252, 188, 149, 207, 205,  55,  63,  91, 209,
                    83,  57, 132,  60,  65, 162, 109,  71,  20,  42, 158,  93,  86, 242, 211, 171,
                    68,  17, 146, 217,  35,  32,  46, 137, 180, 124, 184,  38, 119, 153, 227, 165,
                   103,  74, 237, 222, 197,  49, 254,  24,  13,  99, 140, 128, 192, 247, 112,   7)

        Alogtable= ( 1,   3,   5,  15,  17,  51,  85, 255,  26,  46, 114, 150, 161, 248,  19,  53,
                    95, 225,  56,  72, 216, 115, 149, 164, 247,   2,   6,  10,  30,  34, 102, 170,
                   229,  52,  92, 228,  55,  89, 235,  38, 106, 190, 217, 112, 144, 171, 230,  49,
                    83, 245,   4,  12,  20,  60,  68, 204,  79, 209, 104, 184, 211, 110, 178, 205,
                    76, 212, 103, 169, 224,  59,  77, 215,  98, 166, 241,   8,  24,  40, 120, 136,
                   131, 158, 185, 208, 107, 189, 220, 127, 129, 152, 179, 206,  73, 219, 118, 154,
                   181, 196,  87, 249,  16,  48,  80, 240,  11,  29,  39, 105, 187, 214,  97, 163,
                   254,  25,  43, 125, 135, 146, 173, 236,  47, 113, 147, 174, 233,  32,  96, 160,
                   251,  22,  58,  78, 210, 109, 183, 194,  93, 231,  50,  86, 250,  21,  63,  65,
                   195,  94, 226,  61,  71, 201,  64, 192,  91, 237,  44, 116, 156, 191, 218, 117,
                   159, 186, 213, 100, 172, 239,  42, 126, 130, 157, 188, 223, 122, 142, 137, 128,
                   155, 182, 193,  88, 232,  35, 101, 175, 234,  37, 111, 177, 200,  67, 197,  84,
                   252,  31,  33,  99, 165, 244,   7,   9,  27,  45, 119, 153, 176, 203,  70, 202,
                    69, 207,  74, 222, 121, 139, 134, 145, 168, 227,  62,  66, 198,  81, 243,  14,
                    18,  54,  90, 238,  41, 123, 141, 140, 143, 138, 133, 148, 167, 242,  13,  23,
                    57,  75, 221, 124, 132, 151, 162, 253,  28,  36, 108, 180, 199,  82, 246,   1)




        """
            AES Encryption Algorithm
            The AES algorithm is just Rijndael algorithm restricted to the default
            blockSize of 128 bits.
        """

        class AES(Rijndael):
            """ The AES algorithm is the Rijndael block cipher restricted to block
                sizes of 128 bits and key sizes of 128, 192 or 256 bits
            """
            def __init__(self, key = None, padding = padWithPadLen(), keySize=16):
                """ Initialize AES, keySize is in bytes """
                if  not (keySize == 16 or keySize == 24 or keySize == 32) :
                    raise BadKeySizeError, 'Illegal AES key size, must be 16, 24, or 32 bytes'

                Rijndael.__init__( self, key, padding=padding, keySize=keySize, blockSize=16 )

                self.name       = 'AES'


        """
            CBC mode of encryption for block ciphers.
            This algorithm mode wraps any BlockCipher to make a
            Cipher Block Chaining mode.
        """
        from random             import Random  # should change to crypto.random!!!


        class CBC(BlockCipher):
            """ The CBC class wraps block ciphers to make cipher block chaining (CBC) mode
                algorithms.  The initialization (IV) is automatic if set to None.  Padding
                is also automatic based on the Pad class used to initialize the algorithm
            """
            def __init__(self, blockCipherInstance, padding = padWithPadLen()):
                """ CBC algorithms are created by initializing with a BlockCipher instance """
                self.baseCipher = blockCipherInstance
                self.name       = self.baseCipher.name + '_CBC'
                self.blockSize  = self.baseCipher.blockSize
                self.keySize    = self.baseCipher.keySize
                self.padding    = padding
                self.baseCipher.padding = noPadding()   # baseCipher should NOT pad!!
                self.r          = Random()            # for IV generation, currently uses
                                                      # mediocre standard distro version     <----------------
                import time
                newSeed = time.ctime()+str(self.r)    # seed with instance location
                self.r.seed(newSeed)                  # to make unique
                self.reset()

            def setKey(self, key):
                self.baseCipher.setKey(key)

            # Overload to reset both CBC state and the wrapped baseCipher
            def resetEncrypt(self):
                BlockCipher.resetEncrypt(self)  # reset CBC encrypt state (super class)
                self.baseCipher.resetEncrypt()  # reset base cipher encrypt state

            def resetDecrypt(self):
                BlockCipher.resetDecrypt(self)  # reset CBC state (super class)
                self.baseCipher.resetDecrypt()  # reset base cipher decrypt state

            def encrypt(self, plainText, iv=None, more=None):
                """ CBC encryption - overloads baseCipher to allow optional explicit IV
                    when iv=None, iv is auto generated!
                """
                if self.encryptBlockCount == 0:
                    self.iv = iv
                else:
                    assert(iv==None), 'IV used only on first call to encrypt'

                return BlockCipher.encrypt(self,plainText, more=more)

            def decrypt(self, cipherText, iv=None, more=None):
                """ CBC decryption - overloads baseCipher to allow optional explicit IV
                    when iv=None, iv is auto generated!
                """
                if self.decryptBlockCount == 0:
                    self.iv = iv
                else:
                    assert(iv==None), 'IV used only on first call to decrypt'

                return BlockCipher.decrypt(self, cipherText, more=more)

            def encryptBlock(self, plainTextBlock):
                """ CBC block encryption, IV is set with 'encrypt' """
                auto_IV = ''
                if self.encryptBlockCount == 0:
                    if self.iv == None:
                        # generate IV and use
                        self.iv = ''.join([chr(self.r.randrange(256)) for i in range(self.blockSize)])
                        self.prior_encr_CT_block = self.iv
                        auto_IV = self.prior_encr_CT_block    # prepend IV if it's automatic
                    else:                       # application provided IV
                        assert(len(self.iv) == self.blockSize ),'IV must be same length as block'
                        self.prior_encr_CT_block = self.iv
                """ encrypt the prior CT XORed with the PT """
                ct = self.baseCipher.encryptBlock( xor(self.prior_encr_CT_block, plainTextBlock) )
                self.prior_encr_CT_block = ct
                return auto_IV+ct

            def decryptBlock(self, encryptedBlock):
                """ Decrypt a single block """

                if self.decryptBlockCount == 0:   # first call, process IV
                    if self.iv == None:    # auto decrypt IV?
                        self.prior_CT_block = encryptedBlock
                        return ''
                    else:
                        assert(len(self.iv)==self.blockSize),"Bad IV size on CBC decryption"
                        self.prior_CT_block = self.iv

                dct = self.baseCipher.decryptBlock(encryptedBlock)
                """ XOR the prior decrypted CT with the prior CT """
                dct_XOR_priorCT = xor( self.prior_CT_block, dct )

                self.prior_CT_block = encryptedBlock

                return dct_XOR_priorCT


        """
            AES_CBC Encryption Algorithm
        """

        class aescbc_AES_CBC(CBC):
            """ AES encryption in CBC feedback mode """
            def __init__(self, key=None, padding=padWithPadLen(), keySize=16):
                CBC.__init__( self, AES(key, noPadding(), keySize), padding)
                self.name       = 'AES_CBC'

        class AES_CBC(object):
            def __init__(self):
                self._key = None
                self._iv = None
                self.aes = None

            def set_decrypt_key(self, userkey, iv):
                self._key = userkey
                self._iv = iv
                self.aes = aescbc_AES_CBC(userkey, noPadding(), len(userkey))

            def decrypt(self, data):
                iv = self._iv
                cleartext = self.aes.decrypt(iv + data)
                return cleartext

        import hmac

        class KeyIVGen(object):
            # this only exists in openssl so we will use pure python implementation instead
            # PKCS5_PBKDF2_HMAC_SHA1 = F(c_int, 'PKCS5_PBKDF2_HMAC_SHA1',
            #                             [c_char_p, c_ulong, c_char_p, c_ulong, c_ulong, c_ulong, c_char_p])
            def pbkdf2(self, passwd, salt, iter, keylen):

                def xorstr( a, b ):
                    if len(a) != len(b):
                        raise Exception("xorstr(): lengths differ")
                    return ''.join((chr(ord(x)^ord(y)) for x, y in zip(a, b)))

                def prf( h, data ):
                    hm = h.copy()
                    hm.update( data )
                    return hm.digest()

                def pbkdf2_F( h, salt, itercount, blocknum ):
                    U = prf( h, salt + pack('>i',blocknum ) )
                    T = U
                    for i in range(2, itercount+1):
                        U = prf( h, U )
                        T = xorstr( T, U )
                    return T

                sha = hashlib.sha1
                digest_size = sha().digest_size
                # l - number of output blocks to produce
                l = keylen / digest_size
                if keylen % digest_size != 0:
                    l += 1
                h = hmac.new( passwd, None, sha )
                T = ""
                for i in range(1, l+1):
                    T += pbkdf2_F( h, salt, iter, i )
                return T[0: keylen]

    def UnprotectHeaderData(encryptedData):
        passwdData = 'header_key_data'
        salt = 'HEADER.2011'
        iter = 0x80
        keylen = 0x100
        key_iv = KeyIVGen().pbkdf2(passwdData, salt, iter, keylen)
        key = key_iv[0:32]
        iv = key_iv[32:48]
        aes=AES_CBC()
        aes.set_decrypt_key(key, iv)
        cleartext = aes.decrypt(encryptedData)
        return cleartext

    # Various character maps used to decrypt kindle info values.
    # Probably supposed to act as obfuscation
    charMap2 = "AaZzB0bYyCc1XxDdW2wEeVv3FfUuG4g-TtHh5SsIiR6rJjQq7KkPpL8lOoMm9Nn_"
    charMap5 = "AzB0bYyCeVvaZ3FfUuG4g-TtHh5SsIiR6rJjQq7KkPpL8lOoMm9Nn_c1XxDdW2wE"
    # New maps in K4PC 1.9.0
    testMap1 = "n5Pr6St7Uv8Wx9YzAb0Cd1Ef2Gh3Jk4M"
    testMap6 = "9YzAb0Cd1Ef2n5Pr6St7Uvh3Jk4M8WxG"
    testMap8 = "YvaZ3FfUm9Nn_c1XuG4yCAzB0beVg-TtHh5SsIiR6rJjQdW2wEq7KkPpL8lOoMxD"

    # interface with Windows OS Routines
    class DataBlob(Structure):
        _fields_ = [('cbData', c_uint),
                    ('pbData', c_void_p)]
    DataBlob_p = POINTER(DataBlob)


    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 = GetSystemDirectory().split('\\')[0] + '\\'):
            vsn = c_uint(0)
            GetVolumeInformationW(path, None, 0, byref(vsn), None, None, None, 0)
            return str(vsn.value)
        return GetVolumeSerialNumber
    GetVolumeSerialNumber = GetVolumeSerialNumber()

    def GetIDString():
        vsn = GetVolumeSerialNumber()
        #print('Using Volume Serial Number for ID: '+vsn)
        return vsn

    def getLastError():
        GetLastError = kernel32.GetLastError
        GetLastError.argtypes = None
        GetLastError.restype = c_uint
        def getLastError():
            return GetLastError()
        return getLastError
    getLastError = getLastError()

    def GetUserName():
        GetUserNameW = advapi32.GetUserNameW
        GetUserNameW.argtypes = [c_wchar_p, POINTER(c_uint)]
        GetUserNameW.restype = c_uint
        def GetUserName():
            buffer = create_unicode_buffer(2)
            size = c_uint(len(buffer))
            while not GetUserNameW(buffer, byref(size)):
                errcd = getLastError()
                if errcd == 234:
                    # bad wine implementation up through wine 1.3.21
                    return "AlternateUserName"
                buffer = create_unicode_buffer(len(buffer) * 2)
                size.value = len(buffer)
            # return low byte of the unicode value of each character of the username
            return buffer.value.encode('utf-16-le')[::2]
        return GetUserName
    GetUserName = GetUserName()

    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, flags):
            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, flags, byref(outdata)):
                # raise DrmException("Failed to Unprotect Data")
                return 'failed'
            return string_at(outdata.pbData, outdata.cbData)
        return CryptUnprotectData
    CryptUnprotectData = CryptUnprotectData()

    # Returns Environmental Variables that contain unicode
    def getEnvironmentVariable(name):
        import ctypes
        name = unicode(name) # make sure string argument is unicode
        n = ctypes.windll.kernel32.GetEnvironmentVariableW(name, None, 0)
        if n == 0:
            return None
        buf = ctypes.create_unicode_buffer(u'\0'*n)
        ctypes.windll.kernel32.GetEnvironmentVariableW(name, buf, n)
        return buf.value

    # Locate all of the kindle-info style files and return as list
    def getKindleInfoFiles():
        kInfoFiles = []
        # some 64 bit machines do not have the proper registry key for some reason
        # or the python interface to the 32 vs 64 bit registry is broken
        path = ""
        if 'LOCALAPPDATA' in os.environ.keys():
			# Python 2.x does not return unicode env. Use Python 3.x
            path = winreg.ExpandEnvironmentStrings(u"%LOCALAPPDATA%")
            # this is just another alternative.
            # path = getEnvironmentVariable('LOCALAPPDATA')
            if not os.path.isdir(path):
                path = ""
        else:
            # User Shell Folders show take precedent over Shell Folders if present
            try:
                # this will still break
                regkey = winreg.OpenKey(winreg.HKEY_CURRENT_USER, "Software\\Microsoft\\Windows\\CurrentVersion\\Explorer\\User Shell Folders\\")
                path = winreg.QueryValueEx(regkey, 'Local AppData')[0]
                if not os.path.isdir(path):
                    path = ""
                    try:
                        regkey = winreg.OpenKey(winreg.HKEY_CURRENT_USER, "Software\\Microsoft\\Windows\\CurrentVersion\\Explorer\\Shell Folders\\")
                        path = winreg.QueryValueEx(regkey, 'Local AppData')[0]
                        if not os.path.isdir(path):
                            path = ""
                    except RegError:
                        pass
            except RegError:
                pass

        found = False
        if path == "":
            print ('Could not find the folder in which to look for kinfoFiles.')
        else:
            # Probably not the best. To Fix (shouldn't ignore in encoding) or use utf-8
            print(u'searching for kinfoFiles in ' + path.encode('ascii', 'ignore'))

            # look for (K4PC 1.9.0 and later) .kinf2011 file
            kinfopath = path +'\\Amazon\\Kindle\\storage\\.kinf2011'
            if os.path.isfile(kinfopath):
                found = True
                print('Found K4PC 1.9+ kinf2011 file: ' + kinfopath.encode('ascii','ignore'))
                kInfoFiles.append(kinfopath)

            # look for (K4PC 1.6.0 and later) rainier.2.1.1.kinf file
            kinfopath = path +'\\Amazon\\Kindle\\storage\\rainier.2.1.1.kinf'
            if os.path.isfile(kinfopath):
                found = True
                print('Found K4PC 1.6-1.8 kinf file: ' + kinfopath)
                kInfoFiles.append(kinfopath)

            # look for (K4PC 1.5.0 and later) rainier.2.1.1.kinf file
            kinfopath = path +'\\Amazon\\Kindle For PC\\storage\\rainier.2.1.1.kinf'
            if os.path.isfile(kinfopath):
                found = True
                print('Found K4PC 1.5 kinf file: ' + kinfopath)
                kInfoFiles.append(kinfopath)

           # look for original (earlier than K4PC 1.5.0) kindle-info files
            kinfopath = path +'\\Amazon\\Kindle For PC\\{AMAwzsaPaaZAzmZzZQzgZCAkZ3AjA_AY}\\kindle.info'
            if os.path.isfile(kinfopath):
                found = True
                print('Found K4PC kindle.info file: ' + kinfopath)
                kInfoFiles.append(kinfopath)

        if not found:
            print('No K4PC kindle.info/kinf/kinf2011 files have been found.')
        return kInfoFiles


    # determine type of kindle info provided and return a
    # database of keynames and values
    def getDBfromFile(kInfoFile):
        names = ['kindle.account.tokens','kindle.cookie.item','eulaVersionAccepted','login_date','kindle.token.item','login','kindle.key.item','kindle.name.info','kindle.device.info', 'MazamaRandomNumber', 'max_date', 'SIGVERIF']
        DB = {}
        with open(kInfoFile, 'rb') as infoReader:
            hdr = infoReader.read(1)
            data = infoReader.read()

        if data.find('{') != -1 :
            # older style kindle-info file
            items = data.split('{')
            for item in items:
                if item != '':
                    keyhash, rawdata = item.split(':')
                    keyname = "unknown"
                    for name in names:
                        if encodeHash(name,charMap2) == keyhash:
                            keyname = name
                            break
                    if keyname == "unknown":
                        keyname = keyhash
                    encryptedValue = decode(rawdata,charMap2)
                    DB[keyname] = CryptUnprotectData(encryptedValue, "", 0)
        elif hdr == '/':
            # else rainier-2-1-1 .kinf file
            # the .kinf file uses "/" to separate it into records
            # so remove the trailing "/" to make it easy to use split
            data = data[:-1]
            items = data.split('/')

            # loop through the item records until all are processed
            while len(items) > 0:

                # get the first item record
                item = items.pop(0)

                # the first 32 chars of the first record of a group
                # is the MD5 hash of the key name encoded by charMap5
                keyhash = item[0:32]

                # the raw keyhash string is used to create entropy for the actual
                # CryptProtectData Blob that represents that keys contents
                entropy = SHA1(keyhash)

                # the remainder of the first record when decoded with charMap5
                # has the ':' split char followed by the string representation
                # of the number of records that follow
                # and make up the contents
                srcnt = decode(item[34:],charMap5)
                rcnt = int(srcnt)

                # read and store in rcnt records of data
                # that make up the contents value
                edlst = []
                for i in xrange(rcnt):
                    item = items.pop(0)
                    edlst.append(item)

                keyname = "unknown"
                for name in names:
                    if encodeHash(name,charMap5) == keyhash:
                        keyname = name
                        break
                if keyname == "unknown":
                    keyname = keyhash
                # the charMap5 encoded contents data has had a length
                # of chars (always odd) cut off of the front and moved
                # to the end to prevent decoding using charMap5 from
                # working properly, and thereby preventing the ensuing
                # CryptUnprotectData call from succeeding.

                # The offset into the charMap5 encoded contents seems to be:
                # len(contents)-largest prime number <=  int(len(content)/3)
                # (in other words split "about" 2/3rds of the way through)

                # move first offsets chars to end to align for decode by charMap5
                encdata = "".join(edlst)
                contlen = len(encdata)
                noffset = contlen - primes(int(contlen/3))[-1]

                # now properly split and recombine
                # by moving noffset chars from the start of the
                # string to the end of the string
                pfx = encdata[0:noffset]
                encdata = encdata[noffset:]
                encdata = encdata + pfx

                # decode using Map5 to get the CryptProtect Data
                encryptedValue = decode(encdata,charMap5)
                DB[keyname] = CryptUnprotectData(encryptedValue, entropy, 1)
        else:
            # else newest .kinf2011 style .kinf file
            # the .kinf file uses "/" to separate it into records
            # so remove the trailing "/" to make it easy to use split
            # need to put back the first char read because it it part
            # of the added entropy blob
            data = hdr + data[:-1]
            items = data.split('/')

            # starts with and encoded and encrypted header blob
            headerblob = items.pop(0)
            encryptedValue = decode(headerblob, testMap1)
            cleartext = UnprotectHeaderData(encryptedValue)
            # now extract the pieces that form the added entropy
            pattern = re.compile(r'''\[Version:(\d+)\]\[Build:(\d+)\]\[Cksum:([^\]]+)\]\[Guid:([\{\}a-z0-9\-]+)\]''', re.IGNORECASE)
            for m in re.finditer(pattern, cleartext):
                added_entropy = m.group(2) + m.group(4)


            # loop through the item records until all are processed
            while len(items) > 0:

                # get the first item record
                item = items.pop(0)

                # the first 32 chars of the first record of a group
                # is the MD5 hash of the key name encoded by charMap5
                keyhash = item[0:32]

                # the sha1 of raw keyhash string is used to create entropy along
                # with the added entropy provided above from the headerblob
                entropy = SHA1(keyhash) + added_entropy

                # the remainder of the first record when decoded with charMap5
                # has the ':' split char followed by the string representation
                # of the number of records that follow
                # and make up the contents
                srcnt = decode(item[34:],charMap5)
                rcnt = int(srcnt)

                # read and store in rcnt records of data
                # that make up the contents value
                edlst = []
                for i in xrange(rcnt):
                    item = items.pop(0)
                    edlst.append(item)

                # key names now use the new testMap8 encoding
                keyname = "unknown"
                for name in names:
                    if encodeHash(name,testMap8) == keyhash:
                        keyname = name
                        break

                # the testMap8 encoded contents data has had a length
                # of chars (always odd) cut off of the front and moved
                # to the end to prevent decoding using testMap8 from
                # working properly, and thereby preventing the ensuing
                # CryptUnprotectData call from succeeding.

                # The offset into the testMap8 encoded contents seems to be:
                # len(contents)-largest prime number <=  int(len(content)/3)
                # (in other words split "about" 2/3rds of the way through)

                # move first offsets chars to end to align for decode by testMap8
                # by moving noffset chars from the start of the
                # string to the end of the string
                encdata = "".join(edlst)
                contlen = len(encdata)
                noffset = contlen - primes(int(contlen/3))[-1]
                pfx = encdata[0:noffset]
                encdata = encdata[noffset:]
                encdata = encdata + pfx

                # decode using new testMap8 to get the original CryptProtect Data
                encryptedValue = decode(encdata,testMap8)
                cleartext = CryptUnprotectData(encryptedValue, entropy, 1)
                DB[keyname] = cleartext

        if 'kindle.account.tokens' in DB:
            # store values used in decryption
            DB['IDString'] = GetIDString()
            DB['UserName'] = GetUserName()
            print u"Decrypted key file using IDString '{0:s}' and UserName '{1:s}'".format(GetIDString(), GetUserName().encode('hex'))
        else:
            DB = {}
        return DB
elif isosx:
    import copy
    import subprocess

    # interface to needed routines in openssl's libcrypto
    def _load_crypto_libcrypto():
        from ctypes import CDLL, byref, POINTER, c_void_p, c_char_p, c_int, c_long, \
            Structure, c_ulong, create_string_buffer, addressof, string_at, cast
        from ctypes.util import find_library

        libcrypto = find_library('crypto')
        if libcrypto is None:
            raise DrmException(u"libcrypto not found")
        libcrypto = CDLL(libcrypto)

        # From OpenSSL's crypto aes header
        #
        # AES_ENCRYPT     1
        # AES_DECRYPT     0
        # AES_MAXNR 14 (in bytes)
        # AES_BLOCK_SIZE 16 (in bytes)
        #
        # struct aes_key_st {
        #    unsigned long rd_key[4 *(AES_MAXNR + 1)];
        #    int rounds;
        # };
        # typedef struct aes_key_st AES_KEY;
        #
        # int AES_set_decrypt_key(const unsigned char *userKey, const int bits, AES_KEY *key);
        #
        # note:  the ivec string, and output buffer are both mutable
        # void AES_cbc_encrypt(const unsigned char *in, unsigned char *out,
        #     const unsigned long length, const AES_KEY *key, unsigned char *ivec, const int enc);

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

        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

        AES_cbc_encrypt = F(None, 'AES_cbc_encrypt',[c_char_p, c_char_p, c_ulong, AES_KEY_p, c_char_p,c_int])

        AES_set_decrypt_key = F(c_int, 'AES_set_decrypt_key',[c_char_p, c_int, AES_KEY_p])

        # From OpenSSL's Crypto evp/p5_crpt2.c
        #
        # int PKCS5_PBKDF2_HMAC_SHA1(const char *pass, int passlen,
        #                        const unsigned char *salt, int saltlen, int iter,
        #                        int keylen, unsigned char *out);

        PKCS5_PBKDF2_HMAC_SHA1 = F(c_int, 'PKCS5_PBKDF2_HMAC_SHA1',
                                    [c_char_p, c_ulong, c_char_p, c_ulong, c_ulong, c_ulong, c_char_p])

        class LibCrypto(object):
            def __init__(self):
                self._blocksize = 0
                self._keyctx = None
                self._iv = 0

            def set_decrypt_key(self, userkey, iv):
                self._blocksize = len(userkey)
                if (self._blocksize != 16) and (self._blocksize != 24) and (self._blocksize != 32) :
                    raise DrmException(u"AES improper key used")
                    return
                keyctx = self._keyctx = AES_KEY()
                self._iv = iv
                self._userkey = userkey
                rv = AES_set_decrypt_key(userkey, len(userkey) * 8, keyctx)
                if rv < 0:
                    raise DrmException(u"Failed to initialize AES key")

            def decrypt(self, data):
                out = create_string_buffer(len(data))
                mutable_iv = create_string_buffer(self._iv, len(self._iv))
                keyctx = self._keyctx
                rv = AES_cbc_encrypt(data, out, len(data), keyctx, mutable_iv, 0)
                if rv == 0:
                    raise DrmException(u"AES decryption failed")
                return out.raw

            def keyivgen(self, passwd, salt, iter, keylen):
                saltlen = len(salt)
                passlen = len(passwd)
                out = create_string_buffer(keylen)
                rv = PKCS5_PBKDF2_HMAC_SHA1(passwd, passlen, salt, saltlen, iter, keylen, out)
                return out.raw
        return LibCrypto

    def _load_crypto():
        LibCrypto = None
        try:
            LibCrypto = _load_crypto_libcrypto()
        except (ImportError, DrmException):
            pass
        return LibCrypto

    LibCrypto = _load_crypto()

    # Various character maps used to decrypt books. Probably supposed to act as obfuscation
    charMap1 = 'n5Pr6St7Uv8Wx9YzAb0Cd1Ef2Gh3Jk4M'
    charMap2 = 'ZB0bYyc1xDdW2wEV3Ff7KkPpL8UuGA4gz-Tme9Nn_tHh5SvXCsIiR6rJjQaqlOoM'

    # For kinf approach of K4Mac 1.6.X or later
    # On K4PC charMap5 = 'AzB0bYyCeVvaZ3FfUuG4g-TtHh5SsIiR6rJjQq7KkPpL8lOoMm9Nn_c1XxDdW2wE'
    # For Mac they seem to re-use charMap2 here
    charMap5 = charMap2

    # new in K4M 1.9.X
    testMap8 = 'YvaZ3FfUm9Nn_c1XuG4yCAzB0beVg-TtHh5SsIiR6rJjQdW2wEq7KkPpL8lOoMxD'

    # uses a sub process to get the Hard Drive Serial Number using ioreg
    # returns serial numbers of all internal hard drive drives
    def GetVolumesSerialNumbers():
        sernums = []
        sernum = os.getenv('MYSERIALNUMBER')
        if sernum != None:
            sernums.append(sernum.strip())
        cmdline = '/usr/sbin/ioreg -w 0 -r -c AppleAHCIDiskDriver'
        cmdline = cmdline.encode(sys.getfilesystemencoding())
        p = subprocess.Popen(cmdline, shell=True, stdin=None, stdout=subprocess.PIPE, stderr=subprocess.PIPE, close_fds=False)
        out1, out2 = p.communicate()
        reslst = out1.split('\n')
        cnt = len(reslst)
        bsdname = None
        sernum = None
        foundIt = False
        for j in xrange(cnt):
            resline = reslst[j]
            pp = resline.find('\"Serial Number\" = \"')
            if pp >= 0:
                sernum = resline[pp+19:-1]
                sernums.append(sernum.strip())
        return sernums

    def GetUserHomeAppSupKindleDirParitionName():
        home = os.getenv('HOME')
        dpath =  home + '/Library'
        cmdline = '/sbin/mount'
        cmdline = cmdline.encode(sys.getfilesystemencoding())
        p = subprocess.Popen(cmdline, shell=True, stdin=None, stdout=subprocess.PIPE, stderr=subprocess.PIPE, close_fds=False)
        out1, out2 = p.communicate()
        reslst = out1.split('\n')
        cnt = len(reslst)
        disk = ''
        foundIt = False
        for j in xrange(cnt):
            resline = reslst[j]
            if resline.startswith('/dev'):
                (devpart, mpath) = resline.split(' on ')
                dpart = devpart[5:]
                pp = mpath.find('(')
                if pp >= 0:
                    mpath = mpath[:pp-1]
                if dpath.startswith(mpath):
                    disk = dpart
        return disk

    # uses a sub process to get the UUID of the specified disk partition using ioreg
    def GetDiskPartitionUUIDs(diskpart):
        uuids = []
        uuidnum = os.getenv('MYUUIDNUMBER')
        if uuidnum != None:
            uuids.append(strip(uuidnum))
        cmdline = '/usr/sbin/ioreg -l -S -w 0 -r -c AppleAHCIDiskDriver'
        cmdline = cmdline.encode(sys.getfilesystemencoding())
        p = subprocess.Popen(cmdline, shell=True, stdin=None, stdout=subprocess.PIPE, stderr=subprocess.PIPE, close_fds=False)
        out1, out2 = p.communicate()
        reslst = out1.split('\n')
        cnt = len(reslst)
        bsdname = None
        uuidnum = None
        foundIt = False
        nest = 0
        uuidnest = -1
        partnest = -2
        for j in xrange(cnt):
            resline = reslst[j]
            if resline.find('{') >= 0:
                nest += 1
            if resline.find('}') >= 0:
                nest -= 1
            pp = resline.find('\"UUID\" = \"')
            if pp >= 0:
                uuidnum = resline[pp+10:-1]
                uuidnum = uuidnum.strip()
                uuidnest = nest
                if partnest == uuidnest and uuidnest > 0:
                    foundIt = True
                    break
            bb = resline.find('\"BSD Name\" = \"')
            if bb >= 0:
                bsdname = resline[bb+14:-1]
                bsdname = bsdname.strip()
                if (bsdname == diskpart):
                    partnest = nest
                else :
                    partnest = -2
                if partnest == uuidnest and partnest > 0:
                    foundIt = True
                    break
            if nest == 0:
                partnest = -2
                uuidnest = -1
                uuidnum = None
                bsdname = None
        if foundIt:
            uuids.append(uuidnum)
        return uuids

    def GetMACAddressesMunged():
        macnums = []
        macnum = os.getenv('MYMACNUM')
        if macnum != None:
            macnums.append(macnum)
        cmdline = '/sbin/ifconfig en0'
        cmdline = cmdline.encode(sys.getfilesystemencoding())
        p = subprocess.Popen(cmdline, shell=True, stdin=None, stdout=subprocess.PIPE, stderr=subprocess.PIPE, close_fds=False)
        out1, out2 = p.communicate()
        reslst = out1.split('\n')
        cnt = len(reslst)
        macnum = None
        foundIt = False
        for j in xrange(cnt):
            resline = reslst[j]
            pp = resline.find('ether ')
            if pp >= 0:
                macnum = resline[pp+6:-1]
                macnum = macnum.strip()
                # print 'original mac', macnum
                # now munge it up the way Kindle app does
                # by xoring it with 0xa5 and swapping elements 3 and 4
                maclst = macnum.split(':')
                n = len(maclst)
                if n != 6:
                    fountIt = False
                    break
                for i in range(6):
                    maclst[i] = int('0x' + maclst[i], 0)
                mlst = [0x00, 0x00, 0x00, 0x00, 0x00, 0x00]
                mlst[5] = maclst[5] ^ 0xa5
                mlst[4] = maclst[3] ^ 0xa5
                mlst[3] = maclst[4] ^ 0xa5
                mlst[2] = maclst[2] ^ 0xa5
                mlst[1] = maclst[1] ^ 0xa5
                mlst[0] = maclst[0] ^ 0xa5
                macnum = '%0.2x%0.2x%0.2x%0.2x%0.2x%0.2x' % (mlst[0], mlst[1], mlst[2], mlst[3], mlst[4], mlst[5])
                foundIt = True
                break
        if foundIt:
            macnums.append(macnum)
        return macnums


    # uses unix env to get username instead of using sysctlbyname
    def GetUserName():
        username = os.getenv('USER')
        return username

    def GetIDStrings():
        # Return all possible ID Strings
        strings = []
        strings.extend(GetMACAddressesMunged())
        strings.extend(GetVolumesSerialNumbers())
        diskpart = GetUserHomeAppSupKindleDirParitionName()
        strings.extend(GetDiskPartitionUUIDs(diskpart))
        strings.append('9999999999')
        #print strings
        return strings


    # implements an Pseudo Mac Version of Windows built-in Crypto routine
    # used by Kindle for Mac versions < 1.6.0
    class CryptUnprotectData(object):
        def __init__(self, IDString):
            sp = IDString + '!@#' + GetUserName()
            passwdData = encode(SHA256(sp),charMap1)
            salt = '16743'
            self.crp = LibCrypto()
            iter = 0x3e8
            keylen = 0x80
            key_iv = self.crp.keyivgen(passwdData, salt, iter, keylen)
            self.key = key_iv[0:32]
            self.iv = key_iv[32:48]
            self.crp.set_decrypt_key(self.key, self.iv)

        def decrypt(self, encryptedData):
            cleartext = self.crp.decrypt(encryptedData)
            cleartext = decode(cleartext,charMap1)
            return cleartext


    # implements an Pseudo Mac Version of Windows built-in Crypto routine
    # used for Kindle for Mac Versions >= 1.6.0
    class CryptUnprotectDataV2(object):
        def __init__(self, IDString):
            sp = GetUserName() + ':&%:' + IDString
            passwdData = encode(SHA256(sp),charMap5)
            # salt generation as per the code
            salt = 0x0512981d * 2 * 1 * 1
            salt = str(salt) + GetUserName()
            salt = encode(salt,charMap5)
            self.crp = LibCrypto()
            iter = 0x800
            keylen = 0x400
            key_iv = self.crp.keyivgen(passwdData, salt, iter, keylen)
            self.key = key_iv[0:32]
            self.iv = key_iv[32:48]
            self.crp.set_decrypt_key(self.key, self.iv)

        def decrypt(self, encryptedData):
            cleartext = self.crp.decrypt(encryptedData)
            cleartext = decode(cleartext, charMap5)
            return cleartext


    # unprotect the new header blob in .kinf2011
    # used in Kindle for Mac Version >= 1.9.0
    def UnprotectHeaderData(encryptedData):
        passwdData = 'header_key_data'
        salt = 'HEADER.2011'
        iter = 0x80
        keylen = 0x100
        crp = LibCrypto()
        key_iv = crp.keyivgen(passwdData, salt, iter, keylen)
        key = key_iv[0:32]
        iv = key_iv[32:48]
        crp.set_decrypt_key(key,iv)
        cleartext = crp.decrypt(encryptedData)
        return cleartext


    # implements an Pseudo Mac Version of Windows built-in Crypto routine
    # used for Kindle for Mac Versions >= 1.9.0
    class CryptUnprotectDataV3(object):
        def __init__(self, entropy, IDString):
            sp = GetUserName() + '+@#$%+' + IDString
            passwdData = encode(SHA256(sp),charMap2)
            salt = entropy
            self.crp = LibCrypto()
            iter = 0x800
            keylen = 0x400
            key_iv = self.crp.keyivgen(passwdData, salt, iter, keylen)
            self.key = key_iv[0:32]
            self.iv = key_iv[32:48]
            self.crp.set_decrypt_key(self.key, self.iv)

        def decrypt(self, encryptedData):
            cleartext = self.crp.decrypt(encryptedData)
            cleartext = decode(cleartext, charMap2)
            return cleartext


    # Locate the .kindle-info files
    def getKindleInfoFiles():
        # file searches can take a long time on some systems, so just look in known specific places.
        kInfoFiles=[]
        found = False
        home = os.getenv('HOME')
        # check for  .kinf2011 file in new location (App Store Kindle for Mac)
        testpath = home + '/Library/Containers/com.amazon.Kindle/Data/Library/Application Support/Kindle/storage/.kinf2011'
        if os.path.isfile(testpath):
            kInfoFiles.append(testpath)
            print('Found k4Mac kinf2011 file: ' + testpath)
            found = True
        # check for  .kinf2011 files from 1.10
        testpath = home + '/Library/Application Support/Kindle/storage/.kinf2011'
        if os.path.isfile(testpath):
            kInfoFiles.append(testpath)
            print('Found k4Mac kinf2011 file: ' + testpath)
            found = True
        # check for  .rainier-2.1.1-kinf files from 1.6
        testpath = home + '/Library/Application Support/Kindle/storage/.rainier-2.1.1-kinf'
        if os.path.isfile(testpath):
            kInfoFiles.append(testpath)
            print('Found k4Mac rainier file: ' + testpath)
            found = True
        # check for  .kindle-info files from 1.4
        testpath = home + '/Library/Application Support/Kindle/storage/.kindle-info'
        if os.path.isfile(testpath):
            kInfoFiles.append(testpath)
            print('Found k4Mac kindle-info file: ' + testpath)
            found = True
        # check for  .kindle-info file from 1.2.2
        testpath = home + '/Library/Application Support/Amazon/Kindle/storage/.kindle-info'
        if os.path.isfile(testpath):
            kInfoFiles.append(testpath)
            print('Found k4Mac kindle-info file: ' + testpath)
            found = True
        # check for  .kindle-info file from 1.0 beta 1 (27214)
        testpath = home + '/Library/Application Support/Amazon/Kindle for Mac/storage/.kindle-info'
        if os.path.isfile(testpath):
            kInfoFiles.append(testpath)
            print('Found k4Mac kindle-info file: ' + testpath)
            found = True
        if not found:
            print('No k4Mac kindle-info/rainier/kinf2011 files have been found.')
        return kInfoFiles

    # determine type of kindle info provided and return a
    # database of keynames and values
    def getDBfromFile(kInfoFile):
        names = ['kindle.account.tokens','kindle.cookie.item','eulaVersionAccepted','login_date','kindle.token.item','login','kindle.key.item','kindle.name.info','kindle.device.info', 'MazamaRandomNumber', 'max_date', 'SIGVERIF']
        with open(kInfoFile, 'rb') as infoReader:
            filehdr = infoReader.read(1)
            filedata = infoReader.read()

        IDStrings = GetIDStrings()
        for IDString in IDStrings:
            DB = {}
            #print "trying IDString:",IDString
            try:
                hdr = filehdr
                data = filedata
                if data.find('[') != -1 :
                    # older style kindle-info file
                    cud = CryptUnprotectData(IDString)
                    items = data.split('[')
                    for item in items:
                        if item != '':
                            keyhash, rawdata = item.split(':')
                            keyname = 'unknown'
                            for name in names:
                                if encodeHash(name,charMap2) == keyhash:
                                    keyname = name
                                    break
                            if keyname == 'unknown':
                                keyname = keyhash
                            encryptedValue = decode(rawdata,charMap2)
                            cleartext = cud.decrypt(encryptedValue)
                            if len(cleartext) > 0:
                                DB[keyname] = cleartext
                    if 'MazamaRandomNumber' in DB and 'kindle.account.tokens' in DB:
                        break
                elif hdr == '/':
                    # else newer style .kinf file used by K4Mac >= 1.6.0
                    # the .kinf file uses '/' to separate it into records
                    # so remove the trailing '/' to make it easy to use split
                    data = data[:-1]
                    items = data.split('/')
                    cud = CryptUnprotectDataV2(IDString)

                    # loop through the item records until all are processed
                    while len(items) > 0:

                        # get the first item record
                        item = items.pop(0)

                        # the first 32 chars of the first record of a group
                        # is the MD5 hash of the key name encoded by charMap5
                        keyhash = item[0:32]
                        keyname = 'unknown'

                        # the raw keyhash string is also used to create entropy for the actual
                        # CryptProtectData Blob that represents that keys contents
                        # 'entropy' not used for K4Mac only K4PC
                        # entropy = SHA1(keyhash)

                        # the remainder of the first record when decoded with charMap5
                        # has the ':' split char followed by the string representation
                        # of the number of records that follow
                        # and make up the contents
                        srcnt = decode(item[34:],charMap5)
                        rcnt = int(srcnt)

                        # read and store in rcnt records of data
                        # that make up the contents value
                        edlst = []
                        for i in xrange(rcnt):
                            item = items.pop(0)
                            edlst.append(item)

                        keyname = 'unknown'
                        for name in names:
                            if encodeHash(name,charMap5) == keyhash:
                                keyname = name
                                break
                        if keyname == 'unknown':
                            keyname = keyhash

                        # the charMap5 encoded contents data has had a length
                        # of chars (always odd) cut off of the front and moved
                        # to the end to prevent decoding using charMap5 from
                        # working properly, and thereby preventing the ensuing
                        # CryptUnprotectData call from succeeding.

                        # The offset into the charMap5 encoded contents seems to be:
                        # len(contents) - largest prime number less than or equal to int(len(content)/3)
                        # (in other words split 'about' 2/3rds of the way through)

                        # move first offsets chars to end to align for decode by charMap5
                        encdata = ''.join(edlst)
                        contlen = len(encdata)

                        # now properly split and recombine
                        # by moving noffset chars from the start of the
                        # string to the end of the string
                        noffset = contlen - primes(int(contlen/3))[-1]
                        pfx = encdata[0:noffset]
                        encdata = encdata[noffset:]
                        encdata = encdata + pfx

                        # decode using charMap5 to get the CryptProtect Data
                        encryptedValue = decode(encdata,charMap5)
                        cleartext = cud.decrypt(encryptedValue)
                        if len(cleartext) > 0:
                            DB[keyname] = cleartext

                    if 'MazamaRandomNumber' in DB and 'kindle.account.tokens' in DB:
                        break
                else:
                    # the latest .kinf2011 version for K4M 1.9.1
                    # put back the hdr char, it is needed
                    data = hdr + data
                    data = data[:-1]
                    items = data.split('/')

                    # the headerblob is the encrypted information needed to build the entropy string
                    headerblob = items.pop(0)
                    encryptedValue = decode(headerblob, charMap1)
                    cleartext = UnprotectHeaderData(encryptedValue)

                    # now extract the pieces in the same way
                    # this version is different from K4PC it scales the build number by multipying by 735
                    pattern = re.compile(r'''\[Version:(\d+)\]\[Build:(\d+)\]\[Cksum:([^\]]+)\]\[Guid:([\{\}a-z0-9\-]+)\]''', re.IGNORECASE)
                    for m in re.finditer(pattern, cleartext):
                        entropy = str(int(m.group(2)) * 0x2df) + m.group(4)

                    cud = CryptUnprotectDataV3(entropy,IDString)

                    # loop through the item records until all are processed
                    while len(items) > 0:

                        # get the first item record
                        item = items.pop(0)

                        # the first 32 chars of the first record of a group
                        # is the MD5 hash of the key name encoded by charMap5
                        keyhash = item[0:32]
                        keyname = 'unknown'

                        # unlike K4PC the keyhash is not used in generating entropy
                        # entropy = SHA1(keyhash) + added_entropy
                        # entropy = added_entropy

                        # the remainder of the first record when decoded with charMap5
                        # has the ':' split char followed by the string representation
                        # of the number of records that follow
                        # and make up the contents
                        srcnt = decode(item[34:],charMap5)
                        rcnt = int(srcnt)

                        # read and store in rcnt records of data
                        # that make up the contents value
                        edlst = []
                        for i in xrange(rcnt):
                            item = items.pop(0)
                            edlst.append(item)

                        keyname = 'unknown'
                        for name in names:
                            if encodeHash(name,testMap8) == keyhash:
                                keyname = name
                                break
                        if keyname == 'unknown':
                            keyname = keyhash

                        # the testMap8 encoded contents data has had a length
                        # of chars (always odd) cut off of the front and moved
                        # to the end to prevent decoding using testMap8 from
                        # working properly, and thereby preventing the ensuing
                        # CryptUnprotectData call from succeeding.

                        # The offset into the testMap8 encoded contents seems to be:
                        # len(contents) - largest prime number less than or equal to int(len(content)/3)
                        # (in other words split 'about' 2/3rds of the way through)

                        # move first offsets chars to end to align for decode by testMap8
                        encdata = ''.join(edlst)
                        contlen = len(encdata)

                        # now properly split and recombine
                        # by moving noffset chars from the start of the
                        # string to the end of the string
                        noffset = contlen - primes(int(contlen/3))[-1]
                        pfx = encdata[0:noffset]
                        encdata = encdata[noffset:]
                        encdata = encdata + pfx

                        # decode using testMap8 to get the CryptProtect Data
                        encryptedValue = decode(encdata,testMap8)
                        cleartext = cud.decrypt(encryptedValue)
                        # print keyname
                        # print cleartext
                        if len(cleartext) > 0:
                            DB[keyname] = cleartext

                    if 'MazamaRandomNumber' in DB and 'kindle.account.tokens' in DB:
                        break
            except:
                pass
        if 'kindle.account.tokens' in DB:
            # store values used in decryption
            print u"Decrypted key file using IDString '{0:s}' and UserName '{1:s}'".format(IDString, GetUserName())
            DB['IDString'] = IDString
            DB['UserName'] = GetUserName()
        else:
            print u"Couldn't decrypt file."
            DB = {}
        return DB
else:
    def getDBfromFile(kInfoFile):
        raise DrmException(u"This script only runs under Windows or Mac OS X.")
        return {}

def kindlekeys(files = []):
    keys = []
    if files == []:
        files = getKindleInfoFiles()
    for file in files:
        key = getDBfromFile(file)
        if key:
            # convert all values to hex, just in case.
            for keyname in key:
                key[keyname]=key[keyname].encode('hex')
            keys.append(key)
    return keys

# interface for Python DeDRM
# returns single key or multiple keys, depending on path or file passed in
def getkey(outpath, files=[]):
    keys = kindlekeys(files)
    if len(keys) > 0:
        if not os.path.isdir(outpath):
            outfile = outpath
            with file(outfile, 'w') as keyfileout:
                keyfileout.write(json.dumps(keys[0]))
            print u"Saved a key to {0}".format(outfile)
        else:
            keycount = 0
            for key in keys:
                while True:
                    keycount += 1
                    outfile = os.path.join(outpath,u"kindlekey{0:d}.k4i".format(keycount))
                    if not os.path.exists(outfile):
                        break
                with file(outfile, 'w') as keyfileout:
                    keyfileout.write(json.dumps(key))
                print u"Saved a key to {0}".format(outfile)
        return True
    return False

def usage(progname):
    print u"Finds, decrypts and saves the default Kindle For Mac/PC encryption keys."
    print u"Keys are saved to the current directory, or a specified output directory."
    print u"If a file name is passed instead of a directory, only the first key is saved, in that file."
    print u"Usage:"
    print u"    {0:s} [-h] [-k <kindle.info>] [<outpath>]".format(progname)


def cli_main():
    sys.stdout=SafeUnbuffered(sys.stdout)
    sys.stderr=SafeUnbuffered(sys.stderr)
    argv=unicode_argv()
    progname = os.path.basename(argv[0])
    print u"{0} v{1}\nCopyright © 2010-2013 some_updates and Apprentice Alf".format(progname,__version__)

    try:
        opts, args = getopt.getopt(argv[1:], "hk:")
    except getopt.GetoptError, err:
        print u"Error in options or arguments: {0}".format(err.args[0])
        usage(progname)
        sys.exit(2)

    files = []
    for o, a in opts:
        if o == "-h":
            usage(progname)
            sys.exit(0)
        if o == "-k":
            files = [a]

    if len(args) > 1:
        usage(progname)
        sys.exit(2)

    if len(args) == 1:
        # save to the specified file or directory
        outpath = args[0]
        if not os.path.isabs(outpath):
           outpath = os.path.abspath(outpath)
    else:
        # save to the same directory as the script
        outpath = os.path.dirname(argv[0])

    # make sure the outpath is the
    outpath = os.path.realpath(os.path.normpath(outpath))

    if not getkey(outpath, files):
        print u"Could not retrieve Kindle for Mac/PC key."
    return 0


def gui_main():
    try:
        import Tkinter
        import Tkconstants
        import tkMessageBox
        import traceback
    except:
        return cli_main()

    class ExceptionDialog(Tkinter.Frame):
        def __init__(self, root, text):
            Tkinter.Frame.__init__(self, root, border=5)
            label = Tkinter.Label(self, text=u"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)


    argv=unicode_argv()
    root = Tkinter.Tk()
    root.withdraw()
    progpath, progname = os.path.split(argv[0])
    success = False
    try:
        keys = kindlekeys()
        keycount = 0
        for key in keys:
            while True:
                keycount += 1
                outfile = os.path.join(progpath,u"kindlekey{0:d}.k4i".format(keycount))
                if not os.path.exists(outfile):
                    break

            with file(outfile, 'w') as keyfileout:
                keyfileout.write(json.dumps(key))
            success = True
            tkMessageBox.showinfo(progname, u"Key successfully retrieved to {0}".format(outfile))
    except DrmException, e:
        tkMessageBox.showerror(progname, u"Error: {0}".format(str(e)))
    except Exception:
        root.wm_state('normal')
        root.title(progname)
        text = traceback.format_exc()
        ExceptionDialog(root, text).pack(fill=Tkconstants.BOTH, expand=1)
        root.mainloop()
    if not success:
        return 1
    return 0

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