DeDRM_tools/Calibre_Plugins/ignobleepub_plugin/ignobleepub_plugin.py
Apprentice Alf 4f34a9a196 tools v4.0
New calibre plugin interface (0.7.55)
Dropped unswindle.pyw
Added Android patch
2015-03-06 06:59:36 +00:00

383 lines
15 KiB
Python

#!/usr/bin/env python
# ignobleepub_plugin.py
# Released under the terms of the GNU General Public Licence, version 3 or
# later. <http://www.gnu.org/licenses/>
#
# Requires Calibre version 0.7.55 or higher.
#
# All credit given to I <3 Cabbages for the original standalone scripts.
# I had the much easier job of converting them to Calibre a plugin.
#
# This plugin is meant to decrypt Barnes & Noble Epubs that are protected
# with Adobe's Adept encryption. It is meant to function without having to install
# any dependencies... other than having Calibre installed, of course. It will still
# work if you have Python and PyCrypto already installed, but they aren't necessary.
#
# Configuration:
# 1) The easiest way to configure the plugin is to enter your name (Barnes & Noble account
# name) and credit card number (the one used to purchase the books) into the plugin's
# customization window. Highlight the plugin (Ignoble Epub DeDRM) and click the
# "Customize Plugin" button on Calibre's Preferences->Plugins page.
# Enter the name and credit card number separated by a comma: Your Name,1234123412341234
#
# If you've purchased books with more than one credit card, separate the info with
# a colon: Your Name,1234123412341234:Other Name,2345234523452345
#
# ** Method 1 is your only option if you don't have/can't run the original
# I <3 Cabbages scripts on your particular machine. **
#
# 2) If you already have keyfiles generated with I <3 Cabbages' ignoblekeygen.pyw
# script, you can put those keyfiles in Calibre's configuration directory. The easiest
# way to find the correct directory is to go to Calibre's Preferences page... click
# on the 'Miscellaneous' button (looks like a gear), and then click the 'Open Calibre
# configuration directory' button. Paste your keyfiles in there. Just make sure that
# they have different names and are saved with the '.b64' extension (like the ignoblekeygen
# script produces). This directory isn't touched when upgrading Calibre, so it's quite safe
# to leave then there.
#
# All keyfiles from option 2 and all data entered from option 1 will be used to attempt
# to decrypt a book. You can use option 1 or option 2, or a combination of both.
#
#
# Revision history:
# 0.1.0 - Initial release
# 0.1.1 - Allow Windows users to make use of openssl if they have it installed.
# - Incorporated SomeUpdates zipfix routine.
# 0.1.2 - bug fix for non-ascii file names in encryption.xml
# 0.1.3 - Try PyCrypto on Windows first
# 0.1.4 - update zipfix to deal with mimetype not in correct place
# 0.1.5 - update zipfix to deal with completely missing mimetype files
# 0.1.6 - update ot the new calibre plugin interface
"""
Decrypt Barnes & Noble ADEPT encrypted EPUB books.
"""
from __future__ import with_statement
__license__ = 'GPL v3'
import sys
import os
import hashlib
import zlib
import zipfile
import re
from zipfile import ZipFile, ZIP_STORED, ZIP_DEFLATED
import xml.etree.ElementTree as etree
from contextlib import closing
global AES
global AES2
META_NAMES = ('mimetype', 'META-INF/rights.xml', 'META-INF/encryption.xml')
NSMAP = {'adept': 'http://ns.adobe.com/adept',
'enc': 'http://www.w3.org/2001/04/xmlenc#'}
class IGNOBLEError(Exception):
pass
def _load_crypto_libcrypto():
from ctypes import CDLL, POINTER, c_void_p, c_char_p, c_int, c_long, \
Structure, c_ulong, create_string_buffer, cast
from ctypes.util import find_library
if sys.platform.startswith('win'):
libcrypto = find_library('libeay32')
else:
libcrypto = find_library('crypto')
if libcrypto is None:
raise IGNOBLEError('libcrypto not found')
libcrypto = CDLL(libcrypto)
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_set_encrypt_key = F(c_int, 'AES_set_encrypt_key',
[c_char_p, c_int, AES_KEY_p])
AES_set_decrypt_key = F(c_int, 'AES_set_decrypt_key',
[c_char_p, c_int, AES_KEY_p])
AES_cbc_encrypt = F(None, 'AES_cbc_encrypt',
[c_char_p, c_char_p, c_ulong, AES_KEY_p, c_char_p,
c_int])
class AES(object):
def __init__(self, userkey):
self._blocksize = len(userkey)
if (self._blocksize != 16) and (self._blocksize != 24) and (self._blocksize != 32) :
raise IGNOBLEError('AES improper key used')
return
key = self._key = AES_KEY()
rv = AES_set_decrypt_key(userkey, len(userkey) * 8, key)
if rv < 0:
raise IGNOBLEError('Failed to initialize AES key')
def decrypt(self, data):
out = create_string_buffer(len(data))
iv = ("\x00" * self._blocksize)
rv = AES_cbc_encrypt(data, out, len(data), self._key, iv, 0)
if rv == 0:
raise IGNOBLEError('AES decryption failed')
return out.raw
class AES2(object):
def __init__(self, userkey, iv):
self._blocksize = len(userkey)
self._iv = iv
key = self._key = AES_KEY()
rv = AES_set_encrypt_key(userkey, len(userkey) * 8, key)
if rv < 0:
raise IGNOBLEError('Failed to initialize AES Encrypt key')
def encrypt(self, data):
out = create_string_buffer(len(data))
rv = AES_cbc_encrypt(data, out, len(data), self._key, self._iv, 1)
if rv == 0:
raise IGNOBLEError('AES encryption failed')
return out.raw
print 'IgnobleEpub: Using libcrypto.'
return (AES, AES2)
def _load_crypto_pycrypto():
from Crypto.Cipher import AES as _AES
class AES(object):
def __init__(self, key):
self._aes = _AES.new(key, _AES.MODE_CBC)
def decrypt(self, data):
return self._aes.decrypt(data)
class AES2(object):
def __init__(self, key, iv):
self._aes = _AES.new(key, _AES.MODE_CBC, iv)
def encrypt(self, data):
return self._aes.encrypt(data)
print 'IgnobleEpub: Using PyCrypto.'
return (AES, AES2)
def _load_crypto():
_aes = _aes2 = None
cryptolist = (_load_crypto_libcrypto, _load_crypto_pycrypto)
if sys.platform.startswith('win'):
cryptolist = (_load_crypto_pycrypto, _load_crypto_libcrypto)
for loader in cryptolist:
try:
_aes, _aes2 = loader()
break
except (ImportError, IGNOBLEError):
pass
return (_aes, _aes2)
def normalize_name(name): # Strip spaces and convert to lowercase.
return ''.join(x for x in name.lower() if x != ' ')
def generate_keyfile(name, ccn):
name = normalize_name(name) + '\x00'
ccn = ccn + '\x00'
name_sha = hashlib.sha1(name).digest()[:16]
ccn_sha = hashlib.sha1(ccn).digest()[:16]
both_sha = hashlib.sha1(name + ccn).digest()
aes = AES2(ccn_sha, name_sha)
crypt = aes.encrypt(both_sha + ('\x0c' * 0x0c))
userkey = hashlib.sha1(crypt).digest()
return userkey.encode('base64')
class ZipInfo(zipfile.ZipInfo):
def __init__(self, *args, **kwargs):
if 'compress_type' in kwargs:
compress_type = kwargs.pop('compress_type')
super(ZipInfo, self).__init__(*args, **kwargs)
self.compress_type = compress_type
class Decryptor(object):
def __init__(self, bookkey, encryption):
enc = lambda tag: '{%s}%s' % (NSMAP['enc'], tag)
self._aes = AES(bookkey)
encryption = etree.fromstring(encryption)
self._encrypted = encrypted = set()
expr = './%s/%s/%s' % (enc('EncryptedData'), enc('CipherData'),
enc('CipherReference'))
for elem in encryption.findall(expr):
path = elem.get('URI', None)
path = path.encode('utf-8')
if path is not None:
encrypted.add(path)
def decompress(self, bytes):
dc = zlib.decompressobj(-15)
bytes = dc.decompress(bytes)
ex = dc.decompress('Z') + dc.flush()
if ex:
bytes = bytes + ex
return bytes
def decrypt(self, path, data):
if path in self._encrypted:
data = self._aes.decrypt(data)[16:]
data = data[:-ord(data[-1])]
data = self.decompress(data)
return data
def plugin_main(userkey, inpath, outpath):
key = userkey.decode('base64')[:16]
aes = AES(key)
with closing(ZipFile(open(inpath, 'rb'))) as inf:
namelist = set(inf.namelist())
if 'META-INF/rights.xml' not in namelist or \
'META-INF/encryption.xml' not in namelist:
return 1
for name in META_NAMES:
namelist.remove(name)
try: # If the generated keyfile doesn't match the bookkey, this is where it's likely to blow up.
rights = etree.fromstring(inf.read('META-INF/rights.xml'))
adept = lambda tag: '{%s}%s' % (NSMAP['adept'], tag)
expr = './/%s' % (adept('encryptedKey'),)
bookkey = ''.join(rights.findtext(expr))
bookkey = aes.decrypt(bookkey.decode('base64'))
bookkey = bookkey[:-ord(bookkey[-1])]
encryption = inf.read('META-INF/encryption.xml')
decryptor = Decryptor(bookkey[-16:], encryption)
kwds = dict(compression=ZIP_DEFLATED, allowZip64=False)
with closing(ZipFile(open(outpath, 'wb'), 'w', **kwds)) as outf:
zi = ZipInfo('mimetype', compress_type=ZIP_STORED)
outf.writestr(zi, inf.read('mimetype'))
for path in namelist:
data = inf.read(path)
outf.writestr(path, decryptor.decrypt(path, data))
except:
return 2
return 0
from calibre.customize import FileTypePlugin
from calibre.constants import iswindows, isosx
class IgnobleDeDRM(FileTypePlugin):
name = 'Ignoble Epub DeDRM'
description = 'Removes DRM from secure Barnes & Noble epub files. \
Credit given to I <3 Cabbages for the original stand-alone scripts.'
supported_platforms = ['linux', 'osx', 'windows']
author = 'DiapDealer'
version = (0, 1, 6)
minimum_calibre_version = (0, 7, 55) # Compiled python libraries cannot be imported in earlier versions.
file_types = set(['epub'])
on_import = True
def run(self, path_to_ebook):
global AES
global AES2
AES, AES2 = _load_crypto()
if AES == None or AES2 == None:
# Failed to load libcrypto or PyCrypto... Adobe Epubs can't be decrypted.'
raise IGNOBLEError('IgnobleEpub - Failed to load crypto libs.')
return
# Load any keyfiles (*.b64) included Calibre's config directory.
userkeys = []
try:
# Find Calibre's configuration directory.
confpath = os.path.split(os.path.split(self.plugin_path)[0])[0]
print 'IgnobleEpub: Calibre configuration directory = %s' % confpath
files = os.listdir(confpath)
filefilter = re.compile("\.b64$", re.IGNORECASE)
files = filter(filefilter.search, files)
if files:
for filename in files:
fpath = os.path.join(confpath, filename)
with open(fpath, 'rb') as f:
userkeys.append(f.read())
print 'IgnobleEpub: Keyfile %s found in config folder.' % filename
else:
print 'IgnobleEpub: No keyfiles found. Checking plugin customization string.'
except IOError:
print 'IgnobleEpub: Error reading keyfiles from config directory.'
pass
# Get name and credit card number from Plugin Customization
if not userkeys and not self.site_customization:
# Plugin hasn't been configured... do nothing.
raise IGNOBLEError('IgnobleEpub - No keys found. Plugin not configured.')
return
if self.site_customization:
keystuff = self.site_customization
ar = keystuff.split(':')
keycount = 0
for i in ar:
try:
name, ccn = i.split(',')
keycount += 1
except ValueError:
raise IGNOBLEError('IgnobleEpub - Error parsing user supplied data.')
return
# Generate Barnes & Noble EPUB user key from name and credit card number.
userkeys.append( generate_keyfile(name, ccn) )
print 'IgnobleEpub: %d userkey(s) generated from customization data.' % keycount
# Attempt to decrypt epub with each encryption key (generated or provided).
for userkey in userkeys:
# Create a TemporaryPersistent file to work with.
# Check original epub archive for zip errors.
from calibre_plugins.ignobleepub import zipfix
inf = self.temporary_file('.epub')
try:
fr = zipfix.fixZip(path_to_ebook, inf.name)
fr.fix()
except Exception, e:
raise Exception(e)
return
of = self.temporary_file('.epub')
# Give the user key, ebook and TemporaryPersistent file to the Stripper function.
result = plugin_main(userkey, inf.name, of.name)
# Ebook is not a B&N Adept epub... do nothing and pass it on.
# This allows a non-encrypted epub to be imported without error messages.
if result == 1:
print 'IgnobleEpub: Not a B&N Adept Epub... punting.'
of.close()
return path_to_ebook
break
# Decryption was successful return the modified PersistentTemporary
# file to Calibre's import process.
if result == 0:
print 'IgnobleEpub: Encryption successfully removed.'
of.close()
return of.name
break
print 'IgnobleEpub: Encryption key invalid... trying others.'
of.close()
# Something went wrong with decryption.
# Import the original unmolested epub.
of.close
raise IGNOBLEError('IgnobleEpub - Ultimately failed to decrypt.')
return
def customization_help(self, gui=False):
return 'Enter B&N Account name and CC# (separate name and CC# with a comma)'