#!/usr/bin/env python3
# -*- coding: utf-8 -*-
# ineptepub.py
# Copyright © 2009-2020 by i♥cabbages, Apprentice Harper et al.
# Released under the terms of the GNU General Public Licence, version 3
#
# Revision history:
# 1 - Initial release
# 2 - Rename to INEPT, fix exit code
# 5 - Version bump to avoid (?) confusion;
# Improve OS X support by using OpenSSL when available
# 5.1 - Improve OpenSSL error checking
# 5.2 - Fix ctypes error causing segfaults on some systems
# 5.3 - add support for OpenSSL on Windows, fix bug with some versions of libcrypto 0.9.8 prior to path level o
# 5.4 - add support for encoding to 'utf-8' when building up list of files to decrypt from encryption.xml
# 5.5 - On Windows try PyCrypto first, OpenSSL next
# 5.6 - Modify interface to allow use with import
# 5.7 - Fix for potential problem with PyCrypto
# 5.8 - Revised to allow use in calibre plugins to eliminate need for duplicate code
# 5.9 - Fixed to retain zip file metadata (e.g. file modification date)
# 6.0 - moved unicode_argv call inside main for Windows DeDRM compatibility
# 6.1 - Work if TkInter is missing
# 6.2 - Handle UTF-8 file names inside an ePub, fix by Jose Luis
# 6.3 - Add additional check on DER file sanity
# 6.4 - Remove erroneous check on DER file sanity
# 6.5 - Completely remove erroneous check on DER file sanity
# 6.6 - Import tkFileDialog, don't assume something else will import it.
# 7.0 - Add Python 3 compatibility for calibre 5.0
"""
Decrypt Adobe Digital Editions encrypted ePub books.
"""
__license__ = 'GPL v3'
__version__ = "7.0"
import codecs
import sys
import os
import traceback
import zlib
import zipfile
from zipfile import ZipInfo, ZipFile, ZIP_STORED, ZIP_DEFLATED
from contextlib import closing
import xml.etree.ElementTree as etree
# 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):
data = data.encode(self.encoding,"replace")
self.stream.buffer.write(data)
self.stream.buffer.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 '?'.
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)]
return ["ineptepub.py"]
else:
argvencoding = sys.stdin.encoding or "utf-8"
return [arg if isinstance(arg, str) else str(arg, argvencoding) for arg in sys.argv]
class ADEPTError(Exception):
pass
def _load_crypto_libcrypto():
from ctypes import CDLL, POINTER, c_void_p, c_char_p, c_int, c_long, \
Structure, c_ulong, create_string_buffer, cast
from ctypes.util import find_library
if iswindows:
libcrypto = find_library('libeay32')
else:
libcrypto = find_library('crypto')
if libcrypto is None:
raise ADEPTError('libcrypto not found')
libcrypto = CDLL(libcrypto)
RSA_NO_PADDING = 3
AES_MAXNR = 14
c_char_pp = POINTER(c_char_p)
c_int_p = POINTER(c_int)
class RSA(Structure):
pass
RSA_p = POINTER(RSA)
class AES_KEY(Structure):
_fields_ = [('rd_key', c_long * (4 * (AES_MAXNR + 1))),
('rounds', c_int)]
AES_KEY_p = POINTER(AES_KEY)
def F(restype, name, argtypes):
func = getattr(libcrypto, name)
func.restype = restype
func.argtypes = argtypes
return func
d2i_RSAPrivateKey = F(RSA_p, 'd2i_RSAPrivateKey',
[RSA_p, c_char_pp, c_long])
RSA_size = F(c_int, 'RSA_size', [RSA_p])
RSA_private_decrypt = F(c_int, 'RSA_private_decrypt',
[c_int, c_char_p, c_char_p, RSA_p, c_int])
RSA_free = F(None, 'RSA_free', [RSA_p])
AES_set_decrypt_key = F(c_int, 'AES_set_decrypt_key',
[c_char_p, c_int, AES_KEY_p])
AES_cbc_encrypt = F(None, 'AES_cbc_encrypt',
[c_char_p, c_char_p, c_ulong, AES_KEY_p, c_char_p,
c_int])
class RSA(object):
def __init__(self, der):
buf = create_string_buffer(der)
pp = c_char_pp(cast(buf, c_char_p))
rsa = self._rsa = d2i_RSAPrivateKey(None, pp, len(der))
if rsa is None:
raise ADEPTError('Error parsing ADEPT user key DER')
def decrypt(self, from_):
rsa = self._rsa
to = create_string_buffer(RSA_size(rsa))
dlen = RSA_private_decrypt(len(from_), from_, to, rsa,
RSA_NO_PADDING)
if dlen < 0:
raise ADEPTError('RSA decryption failed')
return to[:dlen]
def __del__(self):
if self._rsa is not None:
RSA_free(self._rsa)
self._rsa = None
class AES(object):
def __init__(self, userkey):
self._blocksize = len(userkey)
if (self._blocksize != 16) and (self._blocksize != 24) and (self._blocksize != 32) :
raise ADEPTError('AES improper key used')
return
key = self._key = AES_KEY()
rv = AES_set_decrypt_key(userkey, len(userkey) * 8, key)
if rv < 0:
raise ADEPTError('Failed to initialize AES key')
def decrypt(self, data):
out = create_string_buffer(len(data))
iv = (b"\x00" * self._blocksize)
rv = AES_cbc_encrypt(data, out, len(data), self._key, iv, 0)
if rv == 0:
raise ADEPTError('AES decryption failed')
return out.raw
return (AES, RSA)
def _load_crypto_pycrypto():
from Crypto.Cipher import AES as _AES
from Crypto.PublicKey import RSA as _RSA
# ASN.1 parsing code from tlslite
class ASN1Error(Exception):
pass
class ASN1Parser(object):
class Parser(object):
def __init__(self, bytes):
self.bytes = bytes
self.index = 0
def get(self, length):
if self.index + length > len(self.bytes):
raise ASN1Error("Error decoding ASN.1")
x = 0
for count in range(length):
x <<= 8
x |= self.bytes[self.index]
self.index += 1
return x
def getFixBytes(self, lengthBytes):
bytes = self.bytes[self.index : self.index+lengthBytes]
self.index += lengthBytes
return bytes
def getVarBytes(self, lengthLength):
lengthBytes = self.get(lengthLength)
return self.getFixBytes(lengthBytes)
def getFixList(self, length, lengthList):
l = [0] * lengthList
for x in range(lengthList):
l[x] = self.get(length)
return l
def getVarList(self, length, lengthLength):
lengthList = self.get(lengthLength)
if lengthList % length != 0:
raise ASN1Error("Error decoding ASN.1")
lengthList = int(lengthList/length)
l = [0] * lengthList
for x in range(lengthList):
l[x] = self.get(length)
return l
def startLengthCheck(self, lengthLength):
self.lengthCheck = self.get(lengthLength)
self.indexCheck = self.index
def setLengthCheck(self, length):
self.lengthCheck = length
self.indexCheck = self.index
def stopLengthCheck(self):
if (self.index - self.indexCheck) != self.lengthCheck:
raise ASN1Error("Error decoding ASN.1")
def atLengthCheck(self):
if (self.index - self.indexCheck) < self.lengthCheck:
return False
elif (self.index - self.indexCheck) == self.lengthCheck:
return True
else:
raise ASN1Error("Error decoding ASN.1")
def __init__(self, bytes):
p = self.Parser(bytes)
p.get(1)
self.length = self._getASN1Length(p)
self.value = p.getFixBytes(self.length)
def getChild(self, which):
p = self.Parser(self.value)
for x in range(which+1):
markIndex = p.index
p.get(1)
length = self._getASN1Length(p)
p.getFixBytes(length)
return ASN1Parser(p.bytes[markIndex:p.index])
def _getASN1Length(self, p):
firstLength = p.get(1)
if firstLength<=127:
return firstLength
else:
lengthLength = firstLength & 0x7F
return p.get(lengthLength)
class AES(object):
def __init__(self, key):
self._aes = _AES.new(key, _AES.MODE_CBC, '\x00'*16)
def decrypt(self, data):
return self._aes.decrypt(data)
class RSA(object):
def __init__(self, der):
key = ASN1Parser([ord(x) for x in der])
key = [key.getChild(x).value for x in range(1, 4)]
key = [self.bytesToNumber(v) for v in key]
self._rsa = _RSA.construct(key)
def bytesToNumber(self, bytes):
total = 0
for byte in bytes:
total = (total << 8) + byte
return long(total)
def decrypt(self, data):
return self._rsa.decrypt(data)
return (AES, RSA)
def _load_crypto():
AES = RSA = 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, RSA = loader()
break
except (ImportError, ADEPTError):
pass
return (AES, RSA)
AES, RSA = _load_crypto()
META_NAMES = ('mimetype', 'META-INF/rights.xml', 'META-INF/encryption.xml')
NSMAP = {'adept': 'http://ns.adobe.com/adept',
'enc': 'http://www.w3.org/2001/04/xmlenc#'}
class Decryptor(object):
def __init__(self, bookkey, encryption):
enc = lambda tag: '{%s}%s' % (NSMAP['enc'], tag)
self._aes = AES(bookkey)
encryption = etree.fromstring(encryption)
self._encrypted = encrypted = set()
expr = './%s/%s/%s' % (enc('EncryptedData'), enc('CipherData'),
enc('CipherReference'))
for elem in encryption.findall(expr):
path = elem.get('URI', None)
if path is not None:
path = path.encode('utf-8')
encrypted.add(path)
def decompress(self, bytes):
dc = zlib.decompressobj(-15)
bytes = dc.decompress(bytes)
ex = dc.decompress(b'Z') + dc.flush()
if ex:
bytes = bytes + ex
return bytes
def decrypt(self, path, data):
if path.encode('utf-8') in self._encrypted:
data = self._aes.decrypt(data)[16:]
if type(data[-1]) != int:
place = ord(data[-1])
else:
place = data[-1]
data = data[:-place]
data = self.decompress(data)
return data
# check file to make check whether it's probably an Adobe Adept encrypted ePub
def adeptBook(inpath):
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 False
try:
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))
if len(bookkey) == 172:
return True
except:
# if we couldn't check, assume it is
return True
return False
def decryptBook(userkey, inpath, outpath):
if AES is None:
raise ADEPTError("PyCrypto or OpenSSL must be installed.")
rsa = RSA(userkey)
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:
print("{0:s} is DRM-free.".format(os.path.basename(inpath)))
return 1
for name in META_NAMES:
namelist.remove(name)
try:
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))
if len(bookkey) != 172:
print("{0:s} is not a secure Adobe Adept ePub.".format(os.path.basename(inpath)))
return 1
bookkey = rsa.decrypt(codecs.decode(bookkey.encode('ascii'), 'base64'))
# Padded as per RSAES-PKCS1-v1_5
if bookkey[-17] != '\x00' and bookkey[-17] != 0:
print("Could not decrypt {0:s}. Wrong key".format(os.path.basename(inpath)))
return 2
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')
zi.compress_type=ZIP_STORED
try:
# if the mimetype is present, get its info, including time-stamp
oldzi = inf.getinfo('mimetype')
# copy across fields to be preserved
zi.date_time = oldzi.date_time
zi.comment = oldzi.comment
zi.extra = oldzi.extra
zi.internal_attr = oldzi.internal_attr
# external attributes are dependent on the create system, so copy both.
zi.external_attr = oldzi.external_attr
zi.create_system = oldzi.create_system
except:
pass
outf.writestr(zi, inf.read('mimetype'))
for path in namelist:
data = inf.read(path)
zi = ZipInfo(path)
zi.compress_type=ZIP_DEFLATED
try:
# get the file info, including time-stamp
oldzi = inf.getinfo(path)
# copy across useful fields
zi.date_time = oldzi.date_time
zi.comment = oldzi.comment
zi.extra = oldzi.extra
zi.internal_attr = oldzi.internal_attr
# external attributes are dependent on the create system, so copy both.
zi.external_attr = oldzi.external_attr
zi.create_system = oldzi.create_system
except:
pass
outf.writestr(zi, decryptor.decrypt(path, data))
except:
print("Could not decrypt {0:s} because of an exception:\n{1:s}".format(os.path.basename(inpath), traceback.format_exc()))
return 2
return 0
def cli_main():
sys.stdout=SafeUnbuffered(sys.stdout)
sys.stderr=SafeUnbuffered(sys.stderr)
argv=unicode_argv()
progname = os.path.basename(argv[0])
if len(argv) != 4:
print("usage: {0} ".format(progname))
return 1
keypath, inpath, outpath = argv[1:]
userkey = open(keypath,'rb').read()
result = decryptBook(userkey, inpath, outpath)
if result == 0:
print("Successfully decrypted {0:s} as {1:s}".format(os.path.basename(inpath),os.path.basename(outpath)))
return result
def gui_main():
try:
import tkinter
import tkinter_constants
import tkinter_filedialog
import tkinter_messagebox
import traceback
except:
return cli_main()
class DecryptionDialog(tkinter.Frame):
def __init__(self, root):
tkinter.Frame.__init__(self, root, border=5)
self.status = tkinter.Label(self, text="Select files for decryption")
self.status.pack(fill=tkinter_constants.X, expand=1)
body = tkinter.Frame(self)
body.pack(fill=tkinter_constants.X, expand=1)
sticky = tkinter_constants.E + tkinter_constants.W
body.grid_columnconfigure(1, weight=2)
tkinter.Label(body, text="Key file").grid(row=0)
self.keypath = tkinter.Entry(body, width=30)
self.keypath.grid(row=0, column=1, sticky=sticky)
if os.path.exists("adeptkey.der"):
self.keypath.insert(0, "adeptkey.der")
button = tkinter.Button(body, text="...", command=self.get_keypath)
button.grid(row=0, column=2)
tkinter.Label(body, text="Input file").grid(row=1)
self.inpath = tkinter.Entry(body, width=30)
self.inpath.grid(row=1, column=1, sticky=sticky)
button = tkinter.Button(body, text="...", command=self.get_inpath)
button.grid(row=1, column=2)
tkinter.Label(body, text="Output file").grid(row=2)
self.outpath = tkinter.Entry(body, width=30)
self.outpath.grid(row=2, column=1, sticky=sticky)
button = tkinter.Button(body, text="...", command=self.get_outpath)
button.grid(row=2, column=2)
buttons = tkinter.Frame(self)
buttons.pack()
botton = tkinter.Button(
buttons, text="Decrypt", width=10, command=self.decrypt)
botton.pack(side=tkinter_constants.LEFT)
tkinter.Frame(buttons, width=10).pack(side=tkinter_constants.LEFT)
button = tkinter.Button(
buttons, text="Quit", width=10, command=self.quit)
button.pack(side=tkinter_constants.RIGHT)
def get_keypath(self):
keypath = tkinter_filedialog.askopenfilename(
parent=None, title="Select Adobe Adept \'.der\' key file",
defaultextension=".der",
filetypes=[('Adobe Adept DER-encoded files', '.der'),
('All Files', '.*')])
if keypath:
keypath = os.path.normpath(keypath)
self.keypath.delete(0, tkinter_constants.END)
self.keypath.insert(0, keypath)
return
def get_inpath(self):
inpath = tkinter_filedialog.askopenfilename(
parent=None, title="Select ADEPT-encrypted ePub file to decrypt",
defaultextension=".epub", filetypes=[('ePub files', '.epub')])
if inpath:
inpath = os.path.normpath(inpath)
self.inpath.delete(0, tkinter_constants.END)
self.inpath.insert(0, inpath)
return
def get_outpath(self):
outpath = tkinter_filedialog.asksaveasfilename(
parent=None, title="Select unencrypted ePub file to produce",
defaultextension=".epub", filetypes=[('ePub files', '.epub')])
if outpath:
outpath = os.path.normpath(outpath)
self.outpath.delete(0, tkinter_constants.END)
self.outpath.insert(0, outpath)
return
def decrypt(self):
keypath = self.keypath.get()
inpath = self.inpath.get()
outpath = self.outpath.get()
if not keypath or not os.path.exists(keypath):
self.status['text'] = "Specified key file does not exist"
return
if not inpath or not os.path.exists(inpath):
self.status['text'] = "Specified input file does not exist"
return
if not outpath:
self.status['text'] = "Output file not specified"
return
if inpath == outpath:
self.status['text'] = "Must have different input and output files"
return
userkey = open(keypath,'rb').read()
self.status['text'] = "Decrypting..."
try:
decrypt_status = decryptBook(userkey, inpath, outpath)
except Exception as e:
self.status['text'] = "Error: {0}".format(e.args[0])
return
if decrypt_status == 0:
self.status['text'] = "File successfully decrypted"
else:
self.status['text'] = "The was an error decrypting the file."
root = tkinter.Tk()
root.title("Adobe Adept ePub Decrypter v.{0}".format(__version__))
root.resizable(True, False)
root.minsize(300, 0)
DecryptionDialog(root).pack(fill=tkinter_constants.X, expand=1)
root.mainloop()
return 0
if __name__ == '__main__':
if len(sys.argv) > 1:
sys.exit(cli_main())
sys.exit(gui_main())