DeDRM_tools/DeDRM_plugin/mobidedrm.py

574 lines
23 KiB
Python
Executable File
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
# mobidedrm.py
# Copyright © 2008 The Dark Reverser
# Portions © 20082020 Apprentice Harper et al.
from __future__ import print_function
__license__ = 'GPL v3'
__version__ = "1.0"
# This is a python script. You need a Python interpreter to run it.
# For example, ActiveState Python, which exists for windows.
#
# Changelog
# 0.01 - Initial version
# 0.02 - Huffdic compressed books were not properly decrypted
# 0.03 - Wasn't checking MOBI header length
# 0.04 - Wasn't sanity checking size of data record
# 0.05 - It seems that the extra data flags take two bytes not four
# 0.06 - And that low bit does mean something after all :-)
# 0.07 - The extra data flags aren't present in MOBI header < 0xE8 in size
# 0.08 - ...and also not in Mobi header version < 6
# 0.09 - ...but they are there with Mobi header version 6, header size 0xE4!
# 0.10 - Outputs unencrypted files as-is, so that when run as a Calibre
# import filter it works when importing unencrypted files.
# Also now handles encrypted files that don't need a specific PID.
# 0.11 - use autoflushed stdout and proper return values
# 0.12 - Fix for problems with metadata import as Calibre plugin, report errors
# 0.13 - Formatting fixes: retabbed file, removed trailing whitespace
# and extra blank lines, converted CR/LF pairs at ends of each line,
# and other cosmetic fixes.
# 0.14 - Working out when the extra data flags are present has been problematic
# Versions 7 through 9 have tried to tweak the conditions, but have been
# only partially successful. Closer examination of lots of sample
# files reveals that a confusion has arisen because trailing data entries
# are not encrypted, but it turns out that the multibyte entries
# in utf8 file are encrypted. (Although neither kind gets compressed.)
# This knowledge leads to a simplification of the test for the
# trailing data byte flags - version 5 and higher AND header size >= 0xE4.
# 0.15 - Now outputs 'heartbeat', and is also quicker for long files.
# 0.16 - And reverts to 'done' not 'done.' at the end for unswindle compatibility.
# 0.17 - added modifications to support its use as an imported python module
# both inside calibre and also in other places (ie K4DeDRM tools)
# 0.17a- disabled the standalone plugin feature since a plugin can not import
# a plugin
# 0.18 - It seems that multibyte entries aren't encrypted in a v7 file...
# Removed the disabled Calibre plug-in code
# Permit use of 8-digit PIDs
# 0.19 - It seems that multibyte entries aren't encrypted in a v6 file either.
# 0.20 - Correction: It seems that multibyte entries are encrypted in a v6 file.
# 0.21 - Added support for multiple pids
# 0.22 - revised structure to hold MobiBook as a class to allow an extended interface
# 0.23 - fixed problem with older files with no EXTH section
# 0.24 - add support for type 1 encryption and 'TEXtREAd' books as well
# 0.25 - Fixed support for 'BOOKMOBI' type 1 encryption
# 0.26 - Now enables Text-To-Speech flag and sets clipping limit to 100%
# 0.27 - Correct pid metadata token generation to match that used by skindle (Thank You Bart!)
# 0.28 - slight additional changes to metadata token generation (None -> '')
# 0.29 - It seems that the ideas about when multibyte trailing characters were
# included in the encryption were wrong. They are for DOC compressed
# files, but they are not for HUFF/CDIC compress files!
# 0.30 - Modified interface slightly to work better with new calibre plugin style
# 0.31 - The multibyte encrytion info is true for version 7 files too.
# 0.32 - Added support for "Print Replica" Kindle ebooks
# 0.33 - Performance improvements for large files (concatenation)
# 0.34 - Performance improvements in decryption (libalfcrypto)
# 0.35 - add interface to get mobi_version
# 0.36 - fixed problem with TEXtREAd and getBookTitle interface
# 0.37 - Fixed double announcement for stand-alone operation
# 0.38 - Unicode used wherever possible, cope with absent alfcrypto
# 0.39 - Fixed problem with TEXtREAd and getBookType interface
# 0.40 - moved unicode_argv call inside main for Windows DeDRM compatibility
# 0.41 - Fixed potential unicode problem in command line calls
# 0.42 - Added GPL v3 licence. updated/removed some print statements
# 1.0 - Python 3 compatibility for calibre 5.0
import sys
import os
import struct
import binascii
try:
from alfcrypto import Pukall_Cipher
except:
print("AlfCrypto not found. Using python PC1 implementation.")
# 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,str) or isinstance(data,unicode):
# str for Python3, unicode for Python2
data = data.encode(self.encoding,"replace")
try:
buffer = getattr(self.stream, 'buffer', self.stream)
# self.stream.buffer for Python3, self.stream for Python2
buffer.write(data)
buffer.flush()
except:
# We can do nothing if a write fails
raise
def __getattr__(self, attr):
return getattr(self.stream, attr)
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 '?'.
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
range(start, argc.value)]
# if we don't have any arguments at all, just pass back script name
# this should never happen
return ["mobidedrm.py"]
else:
argvencoding = sys.stdin.encoding or "utf-8"
return [arg if (isinstance(arg, str) or isinstance(arg,unicode)) else str(arg, argvencoding) for arg in sys.argv]
class DrmException(Exception):
pass
#
# MobiBook Utility Routines
#
# Implementation of Pukall Cipher 1
def PC1(key, src, decryption=True):
# if we can get it from alfcrypto, use that
try:
return Pukall_Cipher().PC1(key,src,decryption)
except NameError:
pass
except TypeError:
pass
# use slow python version, since Pukall_Cipher didn't load
sum1 = 0;
sum2 = 0;
keyXorVal = 0;
if len(key)!=16:
DrmException ("PC1: Bad key length")
wkey = []
for i in range(8):
wkey.append(key[i*2]<<8 | key[i*2+1])
dst = b''
for i in range(len(src)):
temp1 = 0;
byteXorVal = 0;
for j in range(8):
temp1 ^= wkey[j]
sum2 = (sum2+j)*20021 + sum1
sum1 = (temp1*346)&0xFFFF
sum2 = (sum2+sum1)&0xFFFF
temp1 = (temp1*20021+1)&0xFFFF
byteXorVal ^= temp1 ^ sum2
curByte = src[i]
if not decryption:
keyXorVal = curByte * 257;
curByte = ((curByte ^ (byteXorVal >> 8)) ^ byteXorVal) & 0xFF
if decryption:
keyXorVal = curByte * 257;
for j in range(8):
wkey[j] ^= keyXorVal;
dst+=bytes([curByte])
return dst
# accepts unicode returns unicode
def checksumPid(s):
letters = 'ABCDEFGHIJKLMNPQRSTUVWXYZ123456789'
crc = (~binascii.crc32(s.encode('utf-8'),-1))&0xFFFFFFFF
crc = crc ^ (crc >> 16)
res = s
l = len(letters)
for i in (0,1):
b = crc & 0xff
pos = (b // l) ^ (b % l)
res += letters[pos%l]
crc >>= 8
return res
# expects bytearray
def getSizeOfTrailingDataEntries(ptr, size, flags):
def getSizeOfTrailingDataEntry(ptr, size):
bitpos, result = 0, 0
if size <= 0:
return result
while True:
v = ptr[size-1]
result |= (v & 0x7F) << bitpos
bitpos += 7
size -= 1
if (v & 0x80) != 0 or (bitpos >= 28) or (size == 0):
return result
num = 0
testflags = flags >> 1
while testflags:
if testflags & 1:
num += getSizeOfTrailingDataEntry(ptr, size - num)
testflags >>= 1
# Check the low bit to see if there's multibyte data present.
# if multibyte data is included in the encryped data, we'll
# have already cleared this flag.
if flags & 1:
num += (ptr[size - num - 1] & 0x3) + 1
return num
class MobiBook:
def loadSection(self, section):
if (section + 1 == self.num_sections):
endoff = len(self.data_file)
else:
endoff = self.sections[section + 1][0]
off = self.sections[section][0]
return self.data_file[off:endoff]
def cleanup(self):
# to match function in Topaz book
pass
def __init__(self, infile):
print("MobiDeDrm v{0:s}.\nCopyright © 2008-2020 The Dark Reverser, Apprentice Harper et al.".format(__version__))
try:
from alfcrypto import Pukall_Cipher
except:
print("AlfCrypto not found. Using python PC1 implementation.")
# initial sanity check on file
self.data_file = open(infile, 'rb').read()
self.mobi_data = ''
self.header = self.data_file[0:78]
if self.header[0x3C:0x3C+8] != b'BOOKMOBI' and self.header[0x3C:0x3C+8] != b'TEXtREAd':
raise DrmException("Invalid file format")
self.magic = self.header[0x3C:0x3C+8]
self.crypto_type = -1
# build up section offset and flag info
self.num_sections, = struct.unpack('>H', self.header[76:78])
self.sections = []
for i in range(self.num_sections):
offset, a1,a2,a3,a4 = struct.unpack('>LBBBB', self.data_file[78+i*8:78+i*8+8])
flags, val = a1, a2<<16|a3<<8|a4
self.sections.append( (offset, flags, val) )
# parse information from section 0
self.sect = self.loadSection(0)
self.records, = struct.unpack('>H', self.sect[0x8:0x8+2])
self.compression, = struct.unpack('>H', self.sect[0x0:0x0+2])
# det default values before PalmDoc test
self.print_replica = False
self.extra_data_flags = 0
self.meta_array = {}
self.mobi_length = 0
self.mobi_codepage = 1252
self.mobi_version = -1
if self.magic == b'TEXtREAd':
print("PalmDoc format book detected.")
return
self.mobi_length, = struct.unpack('>L',self.sect[0x14:0x18])
self.mobi_codepage, = struct.unpack('>L',self.sect[0x1c:0x20])
self.mobi_version, = struct.unpack('>L',self.sect[0x68:0x6C])
#print "MOBI header version {0:d}, header length {1:d}".format(self.mobi_version, self.mobi_length)
if (self.mobi_length >= 0xE4) and (self.mobi_version >= 5):
self.extra_data_flags, = struct.unpack('>H', self.sect[0xF2:0xF4])
#print "Extra Data Flags: {0:d}".format(self.extra_data_flags)
if (self.compression != 17480):
# multibyte utf8 data is included in the encryption for PalmDoc compression
# so clear that byte so that we leave it to be decrypted.
self.extra_data_flags &= 0xFFFE
# if exth region exists parse it for metadata array
try:
exth_flag, = struct.unpack('>L', self.sect[0x80:0x84])
exth = b''
if exth_flag & 0x40:
exth = self.sect[16 + self.mobi_length:]
if (len(exth) >= 12) and (exth[:4] == b'EXTH'):
nitems, = struct.unpack('>I', exth[8:12])
pos = 12
for i in range(nitems):
type, size = struct.unpack('>II', exth[pos: pos + 8])
content = exth[pos + 8: pos + size]
self.meta_array[type] = content
# reset the text to speech flag and clipping limit, if present
if type == 401 and size == 9:
# set clipping limit to 100%
self.patchSection(0, b'\144', 16 + self.mobi_length + pos + 8)
elif type == 404 and size == 9:
# make sure text to speech is enabled
self.patchSection(0, b'\0', 16 + self.mobi_length + pos + 8)
elif type == 405 and size == 9:
# remove rented book flag
self.patchSection(0, b'\0', 16 + self.mobi_length + pos + 8)
elif type == 406 and size == 16:
# remove rental due date
self.patchSection(0, b'\0'*8, 16 + self.mobi_length + pos + 8)
elif type == 208:
# remove watermark (atv:kin: stuff)
self.patchSection(0, b'\0'*(size-8), 16 + self.mobi_length + pos + 8)
# print type, size, content, content.encode('hex')
pos += size
except Exception as e:
print("Cannot set meta_array: Error: {:s}".format(e.args[0]))
#returns unicode
def getBookTitle(self):
codec_map = {
1252 : 'windows-1252',
65001 : 'utf-8',
}
title = b''
codec = 'windows-1252'
if self.magic == b'BOOKMOBI':
if 503 in self.meta_array:
title = self.meta_array[503]
else:
toff, tlen = struct.unpack('>II', self.sect[0x54:0x5c])
tend = toff + tlen
title = self.sect[toff:tend]
if self.mobi_codepage in codec_map.keys():
codec = codec_map[self.mobi_codepage]
if title == b'':
title = self.header[:32]
title = title.split(b'\0')[0]
return title.decode(codec)
def getPIDMetaInfo(self):
rec209 = b''
token = b''
if 209 in self.meta_array:
rec209 = self.meta_array[209]
data = rec209
# The 209 data comes in five byte groups. Interpret the last four bytes
# of each group as a big endian unsigned integer to get a key value
# if that key exists in the meta_array, append its contents to the token
for i in range(0,len(data),5):
val, = struct.unpack('>I',data[i+1:i+5])
sval = self.meta_array.get(val,b'')
token += sval
return rec209, token
# new must be byte array
def patch(self, off, new):
self.data_file = self.data_file[:off] + new + self.data_file[off+len(new):]
# new must be byte array
def patchSection(self, section, new, in_off = 0):
if (section + 1 == self.num_sections):
endoff = len(self.data_file)
else:
endoff = self.sections[section + 1][0]
off = self.sections[section][0]
assert off + in_off + len(new) <= endoff
self.patch(off + in_off, new)
# pids in pidlist must be unicode, returned key is byte array, pid is unicode
def parseDRM(self, data, count, pidlist):
found_key = None
keyvec1 = b'\x72\x38\x33\xB0\xB4\xF2\xE3\xCA\xDF\x09\x01\xD6\xE2\xE0\x3F\x96'
for pid in pidlist:
bigpid = pid.encode('utf-8').ljust(16,b'\0')
temp_key = PC1(keyvec1, bigpid, False)
temp_key_sum = sum(temp_key) & 0xff
found_key = None
for i in range(count):
verification, size, type, cksum, cookie = struct.unpack('>LLLBxxx32s', data[i*0x30:i*0x30+0x30])
if cksum == temp_key_sum:
cookie = PC1(temp_key, cookie)
ver,flags,finalkey,expiry,expiry2 = struct.unpack('>LL16sLL', cookie)
if verification == ver and (flags & 0x1F) == 1:
found_key = finalkey
break
if found_key != None:
break
if not found_key:
# Then try the default encoding that doesn't require a PID
pid = '00000000'
temp_key = keyvec1
temp_key_sum = sum(temp_key) & 0xff
for i in range(count):
verification, size, type, cksum, cookie = struct.unpack('>LLLBxxx32s', data[i*0x30:i*0x30+0x30])
if cksum == temp_key_sum:
cookie = PC1(temp_key, cookie)
ver,flags,finalkey,expiry,expiry2 = struct.unpack('>LL16sLL', cookie)
if verification == ver:
found_key = finalkey
break
return [found_key,pid]
def getFile(self, outpath):
open(outpath,'wb').write(self.mobi_data)
def getBookType(self):
if self.print_replica:
return "Print Replica"
if self.mobi_version >= 8:
return "Kindle Format 8"
if self.mobi_version >= 0:
return "Mobipocket {0:d}".format(self.mobi_version)
return "PalmDoc"
def getBookExtension(self):
if self.print_replica:
return ".azw4"
if self.mobi_version >= 8:
return ".azw3"
return ".mobi"
# pids in pidlist may be unicode or bytearrays or bytes
def processBook(self, pidlist):
crypto_type, = struct.unpack('>H', self.sect[0xC:0xC+2])
print("Crypto Type is: {0:d}".format(crypto_type))
self.crypto_type = crypto_type
if crypto_type == 0:
print("This book is not encrypted.")
# we must still check for Print Replica
self.print_replica = (self.loadSection(1)[0:4] == '%MOP')
self.mobi_data = self.data_file
return
if crypto_type != 2 and crypto_type != 1:
raise DrmException("Cannot decode unknown Mobipocket encryption type {0:d}".format(crypto_type))
if 406 in self.meta_array:
data406 = self.meta_array[406]
val406, = struct.unpack('>Q',data406)
if val406 != 0:
print("Warning: This is a library or rented ebook ({0}). Continuing ...".format(val406))
#raise DrmException("Cannot decode library or rented ebooks.")
goodpids = []
# print("DEBUG ==== pidlist = ", pidlist)
for pid in pidlist:
if isinstance(pid,(bytearray,bytes)):
pid = pid.decode('utf-8')
if len(pid)==10:
if checksumPid(pid[0:-2]) != pid:
print("Warning: PID {0} has incorrect checksum, should have been {1}".format(pid,checksumPid(pid[0:-2])))
goodpids.append(pid[0:-2])
elif len(pid)==8:
goodpids.append(pid)
else:
print("Warning: PID {0} has wrong number of digits".format(pid))
# print("======= DEBUG good pids = ", goodpids)
if self.crypto_type == 1:
t1_keyvec = b'QDCVEPMU675RUBSZ'
if self.magic == b'TEXtREAd':
bookkey_data = self.sect[0x0E:0x0E+16]
elif self.mobi_version < 0:
bookkey_data = self.sect[0x90:0x90+16]
else:
bookkey_data = self.sect[self.mobi_length+16:self.mobi_length+32]
pid = '00000000'
found_key = PC1(t1_keyvec, bookkey_data)
else :
# calculate the keys
drm_ptr, drm_count, drm_size, drm_flags = struct.unpack('>LLLL', self.sect[0xA8:0xA8+16])
if drm_count == 0:
raise DrmException("Encryption not initialised. Must be opened with Mobipocket Reader first.")
found_key, pid = self.parseDRM(self.sect[drm_ptr:drm_ptr+drm_size], drm_count, goodpids)
if not found_key:
raise DrmException("No key found in {0:d} PIDs tried.".format(len(goodpids)))
# kill the drm keys
self.patchSection(0, b'\0' * drm_size, drm_ptr)
# kill the drm pointers
self.patchSection(0, b'\xff' * 4 + b'\0' * 12, 0xA8)
if pid=='00000000':
print("File has default encryption, no specific key needed.")
else:
print("File is encoded with PID {0}.".format(checksumPid(pid)))
# clear the crypto type
self.patchSection(0, b'\0' * 2, 0xC)
# decrypt sections
print("Decrypting. Please wait . . .", end=' ')
mobidataList = []
mobidataList.append(self.data_file[:self.sections[1][0]])
for i in range(1, self.records+1):
data = self.loadSection(i)
extra_size = getSizeOfTrailingDataEntries(data, len(data), self.extra_data_flags)
if i%100 == 0:
print(".", end=' ')
# print "record %d, extra_size %d" %(i,extra_size)
decoded_data = PC1(found_key, data[0:len(data) - extra_size])
if i==1:
self.print_replica = (decoded_data[0:4] == '%MOP')
mobidataList.append(decoded_data)
if extra_size > 0:
mobidataList.append(data[-extra_size:])
if self.num_sections > self.records+1:
mobidataList.append(self.data_file[self.sections[self.records+1][0]:])
self.mobi_data = b''.join(mobidataList)
print("done")
return
# pids in pidlist must be unicode
def getUnencryptedBook(infile,pidlist):
if not os.path.isfile(infile):
raise DrmException("Input File Not Found.")
book = MobiBook(infile)
book.processBook(pidlist)
return book.mobi_data
def cli_main():
argv=unicode_argv()
progname = os.path.basename(argv[0])
if len(argv)<3 or len(argv)>4:
print("MobiDeDrm v{0:s}.\nCopyright © 2008-2020 The Dark Reverser, Apprentice Harper et al.".format(__version__))
print("Removes protection from Kindle/Mobipocket, Kindle/KF8 and Kindle/Print Replica ebooks")
print("Usage:")
print(" {0} <infile> <outfile> [<Comma separated list of PIDs to try>]".format(progname))
return 1
else:
infile = argv[1]
outfile = argv[2]
if len(argv) == 4:
pidlist = argv[3].split(',')
else:
pidlist = []
try:
stripped_file = getUnencryptedBook(infile, pidlist)
open(outfile, 'wb').write(stripped_file)
except DrmException as e:
print("MobiDeDRM v{0} Error: {1:s}".format(__version__,e.args[0]))
return 1
return 0
if __name__ == '__main__':
sys.stdout=SafeUnbuffered(sys.stdout)
sys.stderr=SafeUnbuffered(sys.stderr)
sys.exit(cli_main())