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DeDRM_tools/DeDRM_plugin/ineptpdf.py
Apprentice Harper afa4ac5716 Starting on Version 7.0 using the work done by others. Completely untested. I will be testing things, but I thought I'd get this base version up for others to give pull requests. 
THIS IS ON THE MASTER BRANCH. The Master branch will be Python 3.0 from now on. While Python 2.7 support will not be deliberately broken, all efforts should now focus on Python 3.0 compatibility.

I can see a lot of work has been done. There's more to do. I've bumped the version number of everything I came across to the next major number for Python 3.0 compatibility indication.

Thanks everyone. I hope to update here at least once a week until we have a stable 7.0 release for calibre 5.0
2020-09-26 21:22:47 +01:00

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#! /usr/bin/python
# -*- coding: utf-8 -*-
from __future__ import with_statement
# ineptpdf.py
# Copyright © 2009-2020 by i♥cabbages, Apprentice Harper et al.
# Released under the terms of the GNU General Public Licence, version 3
# <http://www.gnu.org/licenses/>
# Revision history:
# 1 - Initial release
# 2 - Improved determination of key-generation algorithm
# 3 - Correctly handle PDF >=1.5 cross-reference streams
# 4 - Removal of ciando's personal ID
# 5 - Automated decryption of a complete directory
# 6.1 - backward compatibility for 1.7.1 and old adeptkey.der
# 7 - Get cross reference streams and object streams working for input.
# Not yet supported on output but this only effects file size,
# not functionality. (anon2)
# 7.1 - Correct a problem when an old trailer is not followed by startxref
# 7.2 - Correct malformed Mac OS resource forks for Stanza (anon2)
# - Support for cross ref streams on output (decreases file size)
# 7.3 - Correct bug in trailer with cross ref stream that caused the error
# "The root object is missing or invalid" in Adobe Reader. (anon2)
# 7.4 - Force all generation numbers in output file to be 0, like in v6.
# Fallback code for wrong xref improved (search till last trailer
# instead of first) (anon2)
# 7.5 - allow support for OpenSSL to replace pycrypto on all platforms
# implemented ARC4 interface to OpenSSL
# fixed minor typos
# 7.6 - backported AES and other fixes from version 8.4.48
# 7.7 - On Windows try PyCrypto first and OpenSSL next
# 7.8 - Modify interface to allow use of import
# 7.9 - Bug fix for some session key errors when len(bookkey) > length required
# 7.10 - Various tweaks to fix minor problems.
# 7.11 - More tweaks to fix minor problems.
# 7.12 - Revised to allow use in calibre plugins to eliminate need for duplicate code
# 7.13 - Fixed erroneous mentions of ineptepub
# 7.14 - moved unicode_argv call inside main for Windows DeDRM compatibility
# 8.0 - Work if TkInter is missing
# 8.0.1 - Broken Metadata fix.
# 8.0.2 - Add additional check on DER file sanity
# 8.0.3 - Remove erroneous check on DER file sanity
# 8.0.4 - Completely remove erroneous check on DER file sanity
# 8.0.5 - Do not process DRM-free documents
# 8.0.6 - Replace use of float by Decimal for greater precision, and import tkFileDialog
# 9.0.0 - Add Python 3 compatibility for calibre 5
"""
Decrypts Adobe ADEPT-encrypted PDF files.
"""
__license__ = 'GPL v3'
__version__ = "9.0.0"
import sys
import os
import re
import zlib
import struct
import hashlib
from decimal import Decimal
import itertools
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 is None:
self.encoding = "utf-8"
def write(self, data):
if isinstance(data,bytes):
data = data.encode(self.encoding,"replace")
self.stream.write(data)
self.stream.flush()
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)]
return [u"ineptpdf.py"]
else:
argvencoding = sys.stdin.encoding
if argvencoding is None:
argvencoding = "utf-8"
return sys.argv
class ADEPTError(Exception):
pass
import hashlib
def SHA256(message):
ctx = hashlib.sha256()
ctx.update(message)
return ctx.digest()
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 ADEPTError('libcrypto not found')
libcrypto = CDLL(libcrypto)
AES_MAXNR = 14
RSA_NO_PADDING = 3
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)
class RC4_KEY(Structure):
_fields_ = [('x', c_int), ('y', c_int), ('box', c_int * 256)]
RC4_KEY_p = POINTER(RC4_KEY)
class RSA(Structure):
pass
RSA_p = POINTER(RSA)
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])
RC4_set_key = F(None,'RC4_set_key',[RC4_KEY_p, c_int, c_char_p])
RC4_crypt = F(None,'RC4',[RC4_KEY_p, c_int, c_char_p, c_char_p])
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])
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[1:dlen]
def __del__(self):
if self._rsa is not None:
RSA_free(self._rsa)
self._rsa = None
class ARC4(object):
@classmethod
def new(cls, userkey):
self = ARC4()
self._blocksize = len(userkey)
key = self._key = RC4_KEY()
RC4_set_key(key, self._blocksize, userkey)
return self
def __init__(self):
self._blocksize = 0
self._key = None
def decrypt(self, data):
out = create_string_buffer(len(data))
RC4_crypt(self._key, len(data), data, out)
return out.raw
class AES(object):
MODE_CBC = 0
@classmethod
def new(cls, userkey, mode, iv):
self = AES()
self._blocksize = len(userkey)
# mode is ignored since CBCMODE is only thing supported/used so far
self._mode = mode
if (self._blocksize != 16) and (self._blocksize != 24) and (self._blocksize != 32) :
raise ADEPTError('AES improper key used')
return
keyctx = self._keyctx = AES_KEY()
self._iv = iv
rv = AES_set_decrypt_key(userkey, len(userkey) * 8, keyctx)
if rv < 0:
raise ADEPTError('Failed to initialize AES key')
return self
def __init__(self):
self._blocksize = 0
self._keyctx = None
self._iv = 0
self._mode = 0
def decrypt(self, data):
out = create_string_buffer(len(data))
rv = AES_cbc_encrypt(data, out, len(data), self._keyctx, self._iv, 0)
if rv == 0:
raise ADEPTError('AES decryption failed')
return out.raw
return (ARC4, RSA, AES)
def _load_crypto_pycrypto():
from Crypto.PublicKey import RSA as _RSA
from Crypto.Cipher import ARC4 as _ARC4
from Crypto.Cipher import AES as _AES
# 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 ARC4(object):
@classmethod
def new(cls, userkey):
self = ARC4()
self._arc4 = _ARC4.new(userkey)
return self
def __init__(self):
self._arc4 = None
def decrypt(self, data):
return self._arc4.decrypt(data)
class AES(object):
MODE_CBC = _AES.MODE_CBC
@classmethod
def new(cls, userkey, mode, iv):
self = AES()
self._aes = _AES.new(userkey, mode, iv)
return self
def __init__(self):
self._aes = None
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 total
def decrypt(self, data):
return self._rsa.decrypt(data)
return (ARC4, RSA, AES)
def _load_crypto():
ARC4 = RSA = AES = 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:
ARC4, RSA, AES = loader()
break
except (ImportError, ADEPTError):
pass
return (ARC4, RSA, AES)
ARC4, RSA, AES = _load_crypto()
try:
from cStringIO import StringIO
except ImportError:
try:
from StringIO import StringIO
except ImportError:
from io import StringIO
# Do we generate cross reference streams on output?
# 0 = never
# 1 = only if present in input
# 2 = always
GEN_XREF_STM = 1
# This is the value for the current document
gen_xref_stm = False # will be set in PDFSerializer
# PDF parsing routines from pdfminer, with changes for EBX_HANDLER
# Utilities
def choplist(n, seq):
'''Groups every n elements of the list.'''
r = []
for x in seq:
r.append(x)
if len(r) == n:
yield tuple(r)
r = []
return
def nunpack(s, default=0):
'''Unpacks up to 4 bytes big endian.'''
l = len(s)
if not l:
return default
elif l == 1:
return s
elif l == 2:
return struct.unpack('>H', s)[0]
elif l == 3:
return struct.unpack('>L', b'\x00'+s)[0]
elif l == 4:
return struct.unpack('>L', s)[0]
else:
return TypeError('invalid length: %d' % l)
STRICT = 0
# PS Exceptions
class PSException(Exception): pass
class PSEOF(PSException): pass
class PSSyntaxError(PSException): pass
class PSTypeError(PSException): pass
class PSValueError(PSException): pass
# Basic PostScript Types
# PSLiteral
class PSObject(object): pass
class PSLiteral(PSObject):
'''
PS literals (e.g. "/Name").
Caution: Never create these objects directly.
Use PSLiteralTable.intern() instead.
'''
def __init__(self, name):
self.name = name
return
def __repr__(self):
name = []
for char in self.name:
if not char.isalnum():
char = b'#%02x' % char
name.append(char)
return b'/%s' % ''.join(name)
# PSKeyword
class PSKeyword(PSObject):
'''
PS keywords (e.g. "showpage").
Caution: Never create these objects directly.
Use PSKeywordTable.intern() instead.
'''
def __init__(self, name):
self.name = name
return
def __repr__(self):
return self.name
# PSSymbolTable
class PSSymbolTable(object):
'''
Symbol table that stores PSLiteral or PSKeyword.
'''
def __init__(self, classe):
self.dic = {}
self.classe = classe
return
def intern(self, name):
if name in self.dic:
lit = self.dic[name]
else:
lit = self.classe(name)
self.dic[name] = lit
return lit
PSLiteralTable = PSSymbolTable(PSLiteral)
PSKeywordTable = PSSymbolTable(PSKeyword)
LIT = PSLiteralTable.intern
KWD = PSKeywordTable.intern
KEYWORD_BRACE_BEGIN = KWD('{')
KEYWORD_BRACE_END = KWD('}')
KEYWORD_ARRAY_BEGIN = KWD('[')
KEYWORD_ARRAY_END = KWD(']')
KEYWORD_DICT_BEGIN = KWD('<<')
KEYWORD_DICT_END = KWD('>>')
def literal_name(x):
if not isinstance(x, PSLiteral):
if STRICT:
raise PSTypeError('Literal required: %r' % x)
else:
return str(x)
return x.name
def keyword_name(x):
if not isinstance(x, PSKeyword):
if STRICT:
raise PSTypeError('Keyword required: %r' % x)
else:
return str(x)
return x.name
## PSBaseParser
##
EOL = re.compile(r'[\r\n]')
SPC = re.compile(r'\s')
NONSPC = re.compile(r'\S')
HEX = re.compile(r'[0-9a-fA-F]')
END_LITERAL = re.compile(r'[#/%\[\]()<>{}\s]')
END_HEX_STRING = re.compile(r'[^\s0-9a-fA-F]')
HEX_PAIR = re.compile(r'[0-9a-fA-F]{2}|.')
END_NUMBER = re.compile(r'[^0-9]')
END_KEYWORD = re.compile(r'[#/%\[\]()<>{}\s]')
END_STRING = re.compile(r'[()\134]')
OCT_STRING = re.compile(r'[0-7]')
ESC_STRING = { 'b':8, 't':9, 'n':10, 'f':12, 'r':13, '(':40, ')':41, '\\':92 }
class PSBaseParser(object):
'''
Most basic PostScript parser that performs only basic tokenization.
'''
BUFSIZ = 4096
def __init__(self, fp):
self.fp = fp
self.seek(0)
return
def __repr__(self):
return '<PSBaseParser: %r, bufpos=%d>' % (self.fp, self.bufpos)
def flush(self):
return
def close(self):
self.flush()
return
def tell(self):
return self.bufpos+self.charpos
def poll(self, pos=None, n=80):
pos0 = self.fp.tell()
if not pos:
pos = self.bufpos+self.charpos
self.fp.seek(pos)
##print >>sys.stderr, 'poll(%d): %r' % (pos, self.fp.read(n))
self.fp.seek(pos0)
return
def seek(self, pos):
'''
Seeks the parser to the given position.
'''
self.fp.seek(pos)
# reset the status for nextline()
self.bufpos = pos
self.buf = ''
self.charpos = 0
# reset the status for nexttoken()
self.parse1 = self.parse_main
self.tokens = []
return
def fillbuf(self):
if self.charpos < len(self.buf): return
# fetch next chunk.
self.bufpos = self.fp.tell()
self.buf = self.fp.read(self.BUFSIZ)
if not self.buf:
raise PSEOF('Unexpected EOF')
self.charpos = 0
return
def parse_main(self, s, i):
m = NONSPC.search(s, i)
if not m:
return (self.parse_main, len(s))
j = m.start(0)
c = s[j]
self.tokenstart = self.bufpos+j
if c == '%':
self.token = '%'
return (self.parse_comment, j+1)
if c == '/':
self.token = ''
return (self.parse_literal, j+1)
if c in '-+' or c.isdigit():
self.token = c
return (self.parse_number, j+1)
if c == '.':
self.token = c
return (self.parse_decimal, j+1)
if c.isalpha():
self.token = c
return (self.parse_keyword, j+1)
if c == '(':
self.token = ''
self.paren = 1
return (self.parse_string, j+1)
if c == '<':
self.token = ''
return (self.parse_wopen, j+1)
if c == '>':
self.token = ''
return (self.parse_wclose, j+1)
self.add_token(KWD(c))
return (self.parse_main, j+1)
def add_token(self, obj):
self.tokens.append((self.tokenstart, obj))
return
def parse_comment(self, s, i):
m = EOL.search(s, i)
if not m:
self.token += s[i:]
return (self.parse_comment, len(s))
j = m.start(0)
self.token += s[i:j]
# We ignore comments.
#self.tokens.append(self.token)
return (self.parse_main, j)
def parse_literal(self, s, i):
m = END_LITERAL.search(s, i)
if not m:
self.token += s[i:]
return (self.parse_literal, len(s))
j = m.start(0)
self.token += s[i:j]
c = s[j]
if c == '#':
self.hex = ''
return (self.parse_literal_hex, j+1)
self.add_token(LIT(self.token))
return (self.parse_main, j)
def parse_literal_hex(self, s, i):
c = s[i]
if HEX.match(c) and len(self.hex) < 2:
self.hex += c
return (self.parse_literal_hex, i+1)
if self.hex:
self.token += chr(int(self.hex, 16))
return (self.parse_literal, i)
def parse_number(self, s, i):
m = END_NUMBER.search(s, i)
if not m:
self.token += s[i:]
return (self.parse_number, len(s))
j = m.start(0)
self.token += s[i:j]
c = s[j]
if c == '.':
self.token += c
return (self.parse_decimal, j+1)
try:
self.add_token(int(self.token))
except ValueError:
pass
return (self.parse_main, j)
def parse_decimal(self, s, i):
m = END_NUMBER.search(s, i)
if not m:
self.token += s[i:]
return (self.parse_decimal, len(s))
j = m.start(0)
self.token += s[i:j]
self.add_token(Decimal(self.token))
return (self.parse_main, j)
def parse_keyword(self, s, i):
m = END_KEYWORD.search(s, i)
if not m:
self.token += s[i:]
return (self.parse_keyword, len(s))
j = m.start(0)
self.token += s[i:j]
if self.token == 'true':
token = True
elif self.token == 'false':
token = False
else:
token = KWD(self.token)
self.add_token(token)
return (self.parse_main, j)
def parse_string(self, s, i):
m = END_STRING.search(s, i)
if not m:
self.token += s[i:]
return (self.parse_string, len(s))
j = m.start(0)
self.token += s[i:j]
c = s[j]
if c == '\\':
self.oct = ''
return (self.parse_string_1, j+1)
if c == '(':
self.paren += 1
self.token += c
return (self.parse_string, j+1)
if c == ')':
self.paren -= 1
if self.paren:
self.token += c
return (self.parse_string, j+1)
self.add_token(self.token)
return (self.parse_main, j+1)
def parse_string_1(self, s, i):
c = s[i]
if OCT_STRING.match(c) and len(self.oct) < 3:
self.oct += c
return (self.parse_string_1, i+1)
if self.oct:
self.token += chr(int(self.oct, 8))
return (self.parse_string, i)
if c in ESC_STRING:
self.token += chr(ESC_STRING[c])
return (self.parse_string, i+1)
def parse_wopen(self, s, i):
c = s[i]
if c.isspace() or HEX.match(c):
return (self.parse_hexstring, i)
if c == '<':
self.add_token(KEYWORD_DICT_BEGIN)
i += 1
return (self.parse_main, i)
def parse_wclose(self, s, i):
c = s[i]
if c == '>':
self.add_token(KEYWORD_DICT_END)
i += 1
return (self.parse_main, i)
def parse_hexstring(self, s, i):
m = END_HEX_STRING.search(s, i)
if not m:
self.token += s[i:]
return (self.parse_hexstring, len(s))
j = m.start(0)
self.token += s[i:j]
token = HEX_PAIR.sub(lambda m: chr(int(m.group(0), 16)),
SPC.sub('', self.token))
self.add_token(token)
return (self.parse_main, j)
def nexttoken(self):
while not self.tokens:
self.fillbuf()
(self.parse1, self.charpos) = self.parse1(self.buf, self.charpos)
token = self.tokens.pop(0)
return token
def nextline(self):
'''
Fetches a next line that ends either with \\r or \\n.
'''
linebuf = ''
linepos = self.bufpos + self.charpos
eol = False
while 1:
self.fillbuf()
if eol:
c = self.buf[self.charpos]
# handle '\r\n'
if c == '\n':
linebuf += c
self.charpos += 1
break
m = EOL.search(self.buf, self.charpos)
if m:
linebuf += self.buf[self.charpos:m.end(0)]
self.charpos = m.end(0)
if linebuf[-1] == '\r':
eol = True
else:
break
else:
linebuf += self.buf[self.charpos:]
self.charpos = len(self.buf)
return (linepos, linebuf)
def revreadlines(self):
'''
Fetches a next line backword. This is used to locate
the trailers at the end of a file.
'''
self.fp.seek(0, 2)
pos = self.fp.tell()
buf = ''
while 0 < pos:
prevpos = pos
pos = max(0, pos-self.BUFSIZ)
self.fp.seek(pos)
s = self.fp.read(prevpos-pos)
if not s: break
while 1:
n = max(s.rfind('\r'), s.rfind('\n'))
if n == -1:
buf = s + buf
break
yield s[n:]+buf
s = s[:n]
buf = ''
return
## PSStackParser
##
class PSStackParser(PSBaseParser):
def __init__(self, fp):
PSBaseParser.__init__(self, fp)
self.reset()
return
def reset(self):
self.context = []
self.curtype = None
self.curstack = []
self.results = []
return
def seek(self, pos):
PSBaseParser.seek(self, pos)
self.reset()
return
def push(self, *objs):
self.curstack.extend(objs)
return
def pop(self, n):
objs = self.curstack[-n:]
self.curstack[-n:] = []
return objs
def popall(self):
objs = self.curstack
self.curstack = []
return objs
def add_results(self, *objs):
self.results.extend(objs)
return
def start_type(self, pos, type):
self.context.append((pos, self.curtype, self.curstack))
(self.curtype, self.curstack) = (type, [])
return
def end_type(self, type):
if self.curtype != type:
raise PSTypeError('Type mismatch: %r != %r' % (self.curtype, type))
objs = [ obj for (_,obj) in self.curstack ]
(pos, self.curtype, self.curstack) = self.context.pop()
return (pos, objs)
def do_keyword(self, pos, token):
return
def nextobject(self, direct=False):
'''
Yields a list of objects: keywords, literals, strings,
numbers, arrays and dictionaries. Arrays and dictionaries
are represented as Python sequence and dictionaries.
'''
while not self.results:
(pos, token) = self.nexttoken()
##print (pos,token), (self.curtype, self.curstack)
if (isinstance(token, int) or
isinstance(token, Decimal) or
isinstance(token, bool) or
isinstance(token, str) or
isinstance(token, PSLiteral)):
# normal token
self.push((pos, token))
elif token == KEYWORD_ARRAY_BEGIN:
# begin array
self.start_type(pos, 'a')
elif token == KEYWORD_ARRAY_END:
# end array
try:
self.push(self.end_type('a'))
except PSTypeError:
if STRICT: raise
elif token == KEYWORD_DICT_BEGIN:
# begin dictionary
self.start_type(pos, 'd')
elif token == KEYWORD_DICT_END:
# end dictionary
try:
(pos, objs) = self.end_type('d')
if len(objs) % 2 != 0:
print("Incomplete dictionary construct")
objs.append("") # this isn't necessary.
# temporary fix. is this due to rental books?
# raise PSSyntaxError(
# 'Invalid dictionary construct: %r' % objs)
d = dict((literal_name(k), v) \
for (k,v) in choplist(2, objs))
self.push((pos, d))
except PSTypeError:
if STRICT: raise
else:
self.do_keyword(pos, token)
if self.context:
continue
else:
if direct:
return self.pop(1)[0]
self.flush()
obj = self.results.pop(0)
return obj
LITERAL_CRYPT = PSLiteralTable.intern('Crypt')
LITERALS_FLATE_DECODE = (PSLiteralTable.intern('FlateDecode'), PSLiteralTable.intern('Fl'))
LITERALS_LZW_DECODE = (PSLiteralTable.intern('LZWDecode'), PSLiteralTable.intern('LZW'))
LITERALS_ASCII85_DECODE = (PSLiteralTable.intern('ASCII85Decode'), PSLiteralTable.intern('A85'))
## PDF Objects
##
class PDFObject(PSObject): pass
class PDFException(PSException): pass
class PDFTypeError(PDFException): pass
class PDFValueError(PDFException): pass
class PDFNotImplementedError(PSException): pass
## PDFObjRef
##
class PDFObjRef(PDFObject):
def __init__(self, doc, objid, genno):
if objid == 0:
if STRICT:
raise PDFValueError('PDF object id cannot be 0.')
self.doc = doc
self.objid = objid
self.genno = genno
return
def __repr__(self):
return '<PDFObjRef:%d %d>' % (self.objid, self.genno)
def resolve(self):
return self.doc.getobj(self.objid)
# resolve
def resolve1(x):
'''
Resolve an object. If this is an array or dictionary,
it may still contains some indirect objects inside.
'''
while isinstance(x, PDFObjRef):
x = x.resolve()
return x
def resolve_all(x):
'''
Recursively resolve X and all the internals.
Make sure there is no indirect reference within the nested object.
This procedure might be slow.
'''
while isinstance(x, PDFObjRef):
x = x.resolve()
if isinstance(x, list):
x = [ resolve_all(v) for v in x ]
elif isinstance(x, dict):
for (k,v) in x.iteritems():
x[k] = resolve_all(v)
return x
def decipher_all(decipher, objid, genno, x):
'''
Recursively decipher X.
'''
if isinstance(x, str):
return decipher(objid, genno, x)
decf = lambda v: decipher_all(decipher, objid, genno, v)
if isinstance(x, list):
x = [decf(v) for v in x]
elif isinstance(x, dict):
x = dict((k, decf(v)) for (k, v) in x.iteritems())
return x
# Type cheking
def int_value(x):
x = resolve1(x)
if not isinstance(x, int):
if STRICT:
raise PDFTypeError('Integer required: %r' % x)
return 0
return x
def decimal_value(x):
x = resolve1(x)
if not isinstance(x, Decimal):
if STRICT:
raise PDFTypeError('Decimal required: %r' % x)
return 0.0
return x
def num_value(x):
x = resolve1(x)
if not (isinstance(x, int) or isinstance(x, Decimal)):
if STRICT:
raise PDFTypeError('Int or Float required: %r' % x)
return 0
return x
def str_value(x):
x = resolve1(x)
if not isinstance(x, str):
if STRICT:
raise PDFTypeError('String required: %r' % x)
return ''
return x
def list_value(x):
x = resolve1(x)
if not (isinstance(x, list) or isinstance(x, tuple)):
if STRICT:
raise PDFTypeError('List required: %r' % x)
return []
return x
def dict_value(x):
x = resolve1(x)
if not isinstance(x, dict):
if STRICT:
raise PDFTypeError('Dict required: %r' % x)
return {}
return x
def stream_value(x):
x = resolve1(x)
if not isinstance(x, PDFStream):
if STRICT:
raise PDFTypeError('PDFStream required: %r' % x)
return PDFStream({}, '')
return x
# ascii85decode(data)
def ascii85decode(data):
n = b = 0
out = b''
for c in data:
if b'!' <= c and c <= b'u':
n += 1
b = b*85+(c-33)
if n == 5:
out += struct.pack('>L',b)
n = b = 0
elif c == b'z':
assert n == 0
out += b'\0\0\0\0'
elif c == b'~':
if n:
for _ in range(5-n):
b = b*85+84
out += struct.pack('>L',b)[:n-1]
break
return out
## PDFStream type
class PDFStream(PDFObject):
def __init__(self, dic, rawdata, decipher=None):
length = int_value(dic.get('Length', 0))
eol = rawdata[length:]
# quick and dirty fix for false length attribute,
# might not work if the pdf stream parser has a problem
if decipher != None and decipher.__name__ == 'decrypt_aes':
if (len(rawdata) % 16) != 0:
cutdiv = len(rawdata) // 16
rawdata = rawdata[:16*cutdiv]
else:
if eol in (b'\r', b'\n', b'\r\n'):
rawdata = rawdata[:length]
self.dic = dic
self.rawdata = rawdata
self.decipher = decipher
self.data = None
self.decdata = None
self.objid = None
self.genno = None
return
def set_objid(self, objid, genno):
self.objid = objid
self.genno = genno
return
def __repr__(self):
if self.rawdata:
return '<PDFStream(%r): raw=%d, %r>' % \
(self.objid, len(self.rawdata), self.dic)
else:
return '<PDFStream(%r): data=%d, %r>' % \
(self.objid, len(self.data), self.dic)
def decode(self):
assert self.data is None and self.rawdata is not None
data = self.rawdata
if self.decipher:
# Handle encryption
data = self.decipher(self.objid, self.genno, data)
if gen_xref_stm:
self.decdata = data # keep decrypted data
if 'Filter' not in self.dic:
self.data = data
self.rawdata = None
##print self.dict
return
filters = self.dic['Filter']
if not isinstance(filters, list):
filters = [ filters ]
for f in filters:
if f in LITERALS_FLATE_DECODE:
# will get errors if the document is encrypted.
data = zlib.decompress(data)
elif f in LITERALS_LZW_DECODE:
data = ''.join(LZWDecoder(StringIO(data)).run())
elif f in LITERALS_ASCII85_DECODE:
data = ascii85decode(data)
elif f == LITERAL_CRYPT:
raise PDFNotImplementedError('/Crypt filter is unsupported')
else:
raise PDFNotImplementedError('Unsupported filter: %r' % f)
# apply predictors
if 'DP' in self.dic:
params = self.dic['DP']
else:
params = self.dic.get('DecodeParms', {})
if 'Predictor' in params:
pred = int_value(params['Predictor'])
if pred:
if pred != 12:
raise PDFNotImplementedError(
'Unsupported predictor: %r' % pred)
if 'Columns' not in params:
raise PDFValueError(
'Columns undefined for predictor=12')
columns = int_value(params['Columns'])
buf = b''
ent0 = b'\x00' * columns
for i in range(0, len(data), columns+1):
pred = data[i]
ent1 = data[i+1:i+1+columns]
if pred == b'\x02':
ent1 = ''.join(bytes([(a+b) & 255]) \
for (a,b) in zip(ent0,ent1))
buf += ent1
ent0 = ent1
data = buf
self.data = data
self.rawdata = None
return
def get_data(self):
if self.data is None:
self.decode()
return self.data
def get_rawdata(self):
return self.rawdata
def get_decdata(self):
if self.decdata is not None:
return self.decdata
data = self.rawdata
if self.decipher and data:
# Handle encryption
data = self.decipher(self.objid, self.genno, data)
return data
## PDF Exceptions
##
class PDFSyntaxError(PDFException): pass
class PDFNoValidXRef(PDFSyntaxError): pass
class PDFEncryptionError(PDFException): pass
class PDFPasswordIncorrect(PDFEncryptionError): pass
# some predefined literals and keywords.
LITERAL_OBJSTM = PSLiteralTable.intern('ObjStm')
LITERAL_XREF = PSLiteralTable.intern('XRef')
LITERAL_PAGE = PSLiteralTable.intern('Page')
LITERAL_PAGES = PSLiteralTable.intern('Pages')
LITERAL_CATALOG = PSLiteralTable.intern('Catalog')
## XRefs
##
## PDFXRef
##
class PDFXRef(object):
def __init__(self):
self.offsets = None
return
def __repr__(self):
return '<PDFXRef: objs=%d>' % len(self.offsets)
def objids(self):
return self.offsets.iterkeys()
def load(self, parser):
self.offsets = {}
while 1:
try:
(pos, line) = parser.nextline()
except PSEOF:
raise PDFNoValidXRef('Unexpected EOF - file corrupted?')
if not line:
raise PDFNoValidXRef('Premature eof: %r' % parser)
if line.startswith('trailer'):
parser.seek(pos)
break
f = line.strip().split(' ')
if len(f) != 2:
raise PDFNoValidXRef('Trailer not found: %r: line=%r' % (parser, line))
try:
(start, nobjs) = map(int, f)
except ValueError:
raise PDFNoValidXRef('Invalid line: %r: line=%r' % (parser, line))
for objid in range(start, start+nobjs):
try:
(_, line) = parser.nextline()
except PSEOF:
raise PDFNoValidXRef('Unexpected EOF - file corrupted?')
f = line.strip().split(' ')
if len(f) != 3:
raise PDFNoValidXRef('Invalid XRef format: %r, line=%r' % (parser, line))
(pos, genno, use) = f
if use != 'n': continue
self.offsets[objid] = (int(genno), int(pos))
self.load_trailer(parser)
return
KEYWORD_TRAILER = PSKeywordTable.intern('trailer')
def load_trailer(self, parser):
try:
(_,kwd) = parser.nexttoken()
assert kwd is self.KEYWORD_TRAILER
(_,dic) = parser.nextobject(direct=True)
except PSEOF:
x = parser.pop(1)
if not x:
raise PDFNoValidXRef('Unexpected EOF - file corrupted')
(_,dic) = x[0]
self.trailer = dict_value(dic)
return
def getpos(self, objid):
try:
(genno, pos) = self.offsets[objid]
except KeyError:
raise
return (None, pos)
## PDFXRefStream
##
class PDFXRefStream(object):
def __init__(self):
self.index = None
self.data = None
self.entlen = None
self.fl1 = self.fl2 = self.fl3 = None
return
def __repr__(self):
return '<PDFXRef: objids=%s>' % self.index
def objids(self):
for first, size in self.index:
for objid in range(first, first + size):
yield objid
def load(self, parser, debug=0):
(_,objid) = parser.nexttoken() # ignored
(_,genno) = parser.nexttoken() # ignored
(_,kwd) = parser.nexttoken()
(_,stream) = parser.nextobject()
if not isinstance(stream, PDFStream) or \
stream.dic['Type'] is not LITERAL_XREF:
raise PDFNoValidXRef('Invalid PDF stream spec.')
size = stream.dic['Size']
index = stream.dic.get('Index', (0,size))
self.index = zip(itertools.islice(index, 0, None, 2),
itertools.islice(index, 1, None, 2))
(self.fl1, self.fl2, self.fl3) = stream.dic['W']
self.data = stream.get_data()
self.entlen = self.fl1+self.fl2+self.fl3
self.trailer = stream.dic
return
def getpos(self, objid):
offset = 0
for first, size in self.index:
if first <= objid and objid < (first + size):
break
offset += size
else:
raise KeyError(objid)
i = self.entlen * ((objid - first) + offset)
ent = self.data[i:i+self.entlen]
f1 = nunpack(ent[:self.fl1], 1)
if f1 == 1:
pos = nunpack(ent[self.fl1:self.fl1+self.fl2])
genno = nunpack(ent[self.fl1+self.fl2:])
return (None, pos)
elif f1 == 2:
objid = nunpack(ent[self.fl1:self.fl1+self.fl2])
index = nunpack(ent[self.fl1+self.fl2:])
return (objid, index)
# this is a free object
raise KeyError(objid)
## PDFDocument
##
## A PDFDocument object represents a PDF document.
## Since a PDF file is usually pretty big, normally it is not loaded
## at once. Rather it is parsed dynamically as processing goes.
## A PDF parser is associated with the document.
##
class PDFDocument(object):
def __init__(self):
self.xrefs = []
self.objs = {}
self.parsed_objs = {}
self.root = None
self.catalog = None
self.parser = None
self.encryption = None
self.decipher = None
return
# set_parser(parser)
# Associates the document with an (already initialized) parser object.
def set_parser(self, parser):
if self.parser: return
self.parser = parser
# The document is set to be temporarily ready during collecting
# all the basic information about the document, e.g.
# the header, the encryption information, and the access rights
# for the document.
self.ready = True
# Retrieve the information of each header that was appended
# (maybe multiple times) at the end of the document.
self.xrefs = parser.read_xref()
for xref in self.xrefs:
trailer = xref.trailer
if not trailer: continue
# If there's an encryption info, remember it.
if 'Encrypt' in trailer:
#assert not self.encryption
try:
self.encryption = (list_value(trailer['ID']),
dict_value(trailer['Encrypt']))
# fix for bad files
except:
self.encryption = ('ffffffffffffffffffffffffffffffffffff',
dict_value(trailer['Encrypt']))
if 'Root' in trailer:
self.set_root(dict_value(trailer['Root']))
break
else:
raise PDFSyntaxError('No /Root object! - Is this really a PDF?')
# The document is set to be non-ready again, until all the
# proper initialization (asking the password key and
# verifying the access permission, so on) is finished.
self.ready = False
return
# set_root(root)
# Set the Root dictionary of the document.
# Each PDF file must have exactly one /Root dictionary.
def set_root(self, root):
self.root = root
self.catalog = dict_value(self.root)
if self.catalog.get('Type') is not LITERAL_CATALOG:
if STRICT:
raise PDFSyntaxError('Catalog not found!')
return
# initialize(password='')
# Perform the initialization with a given password.
# This step is mandatory even if there's no password associated
# with the document.
def initialize(self, password=''):
if not self.encryption:
self.is_printable = self.is_modifiable = self.is_extractable = True
self.ready = True
raise PDFEncryptionError('Document is not encrypted.')
return
(docid, param) = self.encryption
type = literal_name(param['Filter'])
if type == 'Adobe.APS':
return self.initialize_adobe_ps(password, docid, param)
if type == 'Standard':
return self.initialize_standard(password, docid, param)
if type == 'EBX_HANDLER':
return self.initialize_ebx(password, docid, param)
raise PDFEncryptionError('Unknown filter: param=%r' % param)
def initialize_adobe_ps(self, password, docid, param):
global KEYFILEPATH
self.decrypt_key = self.genkey_adobe_ps(param)
self.genkey = self.genkey_v4
self.decipher = self.decrypt_aes
self.ready = True
return
def genkey_adobe_ps(self, param):
# nice little offline principal keys dictionary
# global static principal key for German Onleihe / Bibliothek Digital
principalkeys = { 'bibliothek-digital.de': 'rRwGv2tbpKov1krvv7PO0ws9S436/lArPlfipz5Pqhw='.decode('base64')}
self.is_printable = self.is_modifiable = self.is_extractable = True
length = int_value(param.get('Length', 0)) / 8
edcdata = str_value(param.get('EDCData')).decode('base64')
pdrllic = str_value(param.get('PDRLLic')).decode('base64')
pdrlpol = str_value(param.get('PDRLPol')).decode('base64')
edclist = []
for pair in edcdata.split('\n'):
edclist.append(pair)
# principal key request
for key in principalkeys:
if key in pdrllic:
principalkey = principalkeys[key]
else:
raise ADEPTError('Cannot find principal key for this pdf')
shakey = SHA256(principalkey)
ivector = 16 * chr(0)
plaintext = AES.new(shakey,AES.MODE_CBC,ivector).decrypt(edclist[9].decode('base64'))
if plaintext[-16:] != 16 * chr(16):
raise ADEPTError('Offlinekey cannot be decrypted, aborting ...')
pdrlpol = AES.new(plaintext[16:32],AES.MODE_CBC,edclist[2].decode('base64')).decrypt(pdrlpol)
if pdrlpol[-1] < 1 or pdrlpol[-1] > 16:
raise ADEPTError('Could not decrypt PDRLPol, aborting ...')
else:
cutter = -1 * pdrlpol[-1]
pdrlpol = pdrlpol[:cutter]
return plaintext[:16]
PASSWORD_PADDING = '(\xbfN^Nu\x8aAd\x00NV\xff\xfa\x01\x08..' \
'\x00\xb6\xd0h>\x80/\x0c\xa9\xfedSiz'
# experimental aes pw support
def initialize_standard(self, password, docid, param):
# copy from a global variable
V = int_value(param.get('V', 0))
if (V <=0 or V > 4):
raise PDFEncryptionError('Unknown algorithm: param=%r' % param)
length = int_value(param.get('Length', 40)) # Key length (bits)
O = str_value(param['O'])
R = int_value(param['R']) # Revision
if 5 <= R:
raise PDFEncryptionError('Unknown revision: %r' % R)
U = str_value(param['U'])
P = int_value(param['P'])
try:
EncMetadata = str_value(param['EncryptMetadata'])
except:
EncMetadata = 'True'
self.is_printable = bool(P & 4)
self.is_modifiable = bool(P & 8)
self.is_extractable = bool(P & 16)
self.is_annotationable = bool(P & 32)
self.is_formsenabled = bool(P & 256)
self.is_textextractable = bool(P & 512)
self.is_assemblable = bool(P & 1024)
self.is_formprintable = bool(P & 2048)
# Algorithm 3.2
password = (password+self.PASSWORD_PADDING)[:32] # 1
hash = hashlib.md5(password) # 2
hash.update(O) # 3
hash.update(struct.pack('<l', P)) # 4
hash.update(docid[0]) # 5
# aes special handling if metadata isn't encrypted
if EncMetadata == ('False' or 'false'):
hash.update('ffffffff'.decode('hex'))
if 5 <= R:
# 8
for _ in range(50):
hash = hashlib.md5(hash.digest()[:length/8])
key = hash.digest()[:length/8]
if R == 2:
# Algorithm 3.4
u1 = ARC4.new(key).decrypt(password)
elif R >= 3:
# Algorithm 3.5
hash = hashlib.md5(self.PASSWORD_PADDING) # 2
hash.update(docid[0]) # 3
x = ARC4.new(key).decrypt(hash.digest()[:16]) # 4
for i in range(1,19+1):
k = ''.join(bytes([c ^ i]) for c in key )
x = ARC4.new(k).decrypt(x)
u1 = x+x # 32bytes total
if R == 2:
is_authenticated = (u1 == U)
else:
is_authenticated = (u1[:16] == U[:16])
if not is_authenticated:
raise ADEPTError('Password is not correct.')
self.decrypt_key = key
# genkey method
if V == 1 or V == 2:
self.genkey = self.genkey_v2
elif V == 3:
self.genkey = self.genkey_v3
elif V == 4:
self.genkey = self.genkey_v2
#self.genkey = self.genkey_v3 if V == 3 else self.genkey_v2
# rc4
if V != 4:
self.decipher = self.decipher_rc4 # XXX may be AES
# aes
elif V == 4 and length == 128:
self.decipher = self.decipher_aes
elif V == 4 and length == 256:
raise PDFNotImplementedError('AES256 encryption is currently unsupported')
self.ready = True
return
def initialize_ebx(self, password, docid, param):
self.is_printable = self.is_modifiable = self.is_extractable = True
rsa = RSA(password)
length = int_value(param.get('Length', 0)) / 8
rights = str_value(param.get('ADEPT_LICENSE')).decode('base64')
rights = zlib.decompress(rights, -15)
rights = etree.fromstring(rights)
expr = './/{http://ns.adobe.com/adept}encryptedKey'
bookkey = ''.join(rights.findtext(expr)).decode('base64')
bookkey = rsa.decrypt(bookkey)
if bookkey[0] != '\x02':
raise ADEPTError('error decrypting book session key')
index = bookkey.index('\0') + 1
bookkey = bookkey[index:]
ebx_V = int_value(param.get('V', 4))
ebx_type = int_value(param.get('EBX_ENCRYPTIONTYPE', 6))
# added because of improper booktype / decryption book session key errors
if length > 0:
if len(bookkey) == length:
if ebx_V == 3:
V = 3
else:
V = 2
elif len(bookkey) == length + 1:
V = bookkey[0]
bookkey = bookkey[1:]
else:
print("ebx_V is %d and ebx_type is %d" % (ebx_V, ebx_type))
print("length is %d and len(bookkey) is %d" % (length, len(bookkey)))
print("bookkey[0] is %d" % bookkey[0])
raise ADEPTError('error decrypting book session key - mismatched length')
else:
# proper length unknown try with whatever you have
print("ebx_V is %d and ebx_type is %d" % (ebx_V, ebx_type))
print("length is %d and len(bookkey) is %d" % (length, len(bookkey)))
print("bookkey[0] is %d" % bookkey[0])
if ebx_V == 3:
V = 3
else:
V = 2
self.decrypt_key = bookkey
self.genkey = self.genkey_v3 if V == 3 else self.genkey_v2
self.decipher = self.decrypt_rc4
self.ready = True
return
# genkey functions
def genkey_v2(self, objid, genno):
objid = struct.pack('<L', objid)[:3]
genno = struct.pack('<L', genno)[:2]
key = self.decrypt_key + objid + genno
hash = hashlib.md5(key)
key = hash.digest()[:min(len(self.decrypt_key) + 5, 16)]
return key
def genkey_v3(self, objid, genno):
objid = struct.pack('<L', objid ^ 0x3569ac)
genno = struct.pack('<L', genno ^ 0xca96)
key = self.decrypt_key
key += objid[0] + genno[0] + objid[1] + genno[1] + objid[2] + 'sAlT'
hash = hashlib.md5(key)
key = hash.digest()[:min(len(self.decrypt_key) + 5, 16)]
return key
# aes v2 and v4 algorithm
def genkey_v4(self, objid, genno):
objid = struct.pack('<L', objid)[:3]
genno = struct.pack('<L', genno)[:2]
key = self.decrypt_key + objid + genno + 'sAlT'
hash = hashlib.md5(key)
key = hash.digest()[:min(len(self.decrypt_key) + 5, 16)]
return key
def decrypt_aes(self, objid, genno, data):
key = self.genkey(objid, genno)
ivector = data[:16]
data = data[16:]
plaintext = AES.new(key,AES.MODE_CBC,ivector).decrypt(data)
# remove pkcs#5 aes padding
cutter = -1 * plaintext[-1]
#print cutter
plaintext = plaintext[:cutter]
return plaintext
def decrypt_aes256(self, objid, genno, data):
key = self.genkey(objid, genno)
ivector = data[:16]
data = data[16:]
plaintext = AES.new(key,AES.MODE_CBC,ivector).decrypt(data)
# remove pkcs#5 aes padding
cutter = -1 * plaintext[-1]
#print cutter
plaintext = plaintext[:cutter]
return plaintext
def decrypt_rc4(self, objid, genno, data):
key = self.genkey(objid, genno)
return ARC4.new(key).decrypt(data)
KEYWORD_OBJ = PSKeywordTable.intern('obj')
def getobj(self, objid):
if not self.ready:
raise PDFException('PDFDocument not initialized')
#assert self.xrefs
if objid in self.objs:
genno = 0
obj = self.objs[objid]
else:
for xref in self.xrefs:
try:
(stmid, index) = xref.getpos(objid)
break
except KeyError:
pass
else:
#if STRICT:
# raise PDFSyntaxError('Cannot locate objid=%r' % objid)
return None
if stmid:
if gen_xref_stm:
return PDFObjStmRef(objid, stmid, index)
# Stuff from pdfminer: extract objects from object stream
stream = stream_value(self.getobj(stmid))
if stream.dic.get('Type') is not LITERAL_OBJSTM:
if STRICT:
raise PDFSyntaxError('Not a stream object: %r' % stream)
try:
n = stream.dic['N']
except KeyError:
if STRICT:
raise PDFSyntaxError('N is not defined: %r' % stream)
n = 0
if stmid in self.parsed_objs:
objs = self.parsed_objs[stmid]
else:
parser = PDFObjStrmParser(stream.get_data(), self)
objs = []
try:
while 1:
(_,obj) = parser.nextobject()
objs.append(obj)
except PSEOF:
pass
self.parsed_objs[stmid] = objs
genno = 0
i = n*2+index
try:
obj = objs[i]
except IndexError:
raise PDFSyntaxError('Invalid object number: objid=%r' % (objid))
if isinstance(obj, PDFStream):
obj.set_objid(objid, 0)
else:
self.parser.seek(index)
(_,objid1) = self.parser.nexttoken() # objid
(_,genno) = self.parser.nexttoken() # genno
#assert objid1 == objid, (objid, objid1)
(_,kwd) = self.parser.nexttoken()
# #### hack around malformed pdf files
# assert objid1 == objid, (objid, objid1)
## if objid1 != objid:
## x = []
## while kwd is not self.KEYWORD_OBJ:
## (_,kwd) = self.parser.nexttoken()
## x.append(kwd)
## if x:
## objid1 = x[-2]
## genno = x[-1]
##
if kwd is not self.KEYWORD_OBJ:
raise PDFSyntaxError(
'Invalid object spec: offset=%r' % index)
(_,obj) = self.parser.nextobject()
if isinstance(obj, PDFStream):
obj.set_objid(objid, genno)
if self.decipher:
obj = decipher_all(self.decipher, objid, genno, obj)
self.objs[objid] = obj
return obj
class PDFObjStmRef(object):
maxindex = 0
def __init__(self, objid, stmid, index):
self.objid = objid
self.stmid = stmid
self.index = index
if index > PDFObjStmRef.maxindex:
PDFObjStmRef.maxindex = index
## PDFParser
##
class PDFParser(PSStackParser):
def __init__(self, doc, fp):
PSStackParser.__init__(self, fp)
self.doc = doc
self.doc.set_parser(self)
return
def __repr__(self):
return '<PDFParser>'
KEYWORD_R = PSKeywordTable.intern('R')
KEYWORD_ENDOBJ = PSKeywordTable.intern('endobj')
KEYWORD_STREAM = PSKeywordTable.intern('stream')
KEYWORD_XREF = PSKeywordTable.intern('xref')
KEYWORD_STARTXREF = PSKeywordTable.intern('startxref')
def do_keyword(self, pos, token):
if token in (self.KEYWORD_XREF, self.KEYWORD_STARTXREF):
self.add_results(*self.pop(1))
return
if token is self.KEYWORD_ENDOBJ:
self.add_results(*self.pop(4))
return
if token is self.KEYWORD_R:
# reference to indirect object
try:
((_,objid), (_,genno)) = self.pop(2)
(objid, genno) = (int(objid), int(genno))
obj = PDFObjRef(self.doc, objid, genno)
self.push((pos, obj))
except PSSyntaxError:
pass
return
if token is self.KEYWORD_STREAM:
# stream object
((_,dic),) = self.pop(1)
dic = dict_value(dic)
try:
objlen = int_value(dic['Length'])
except KeyError:
if STRICT:
raise PDFSyntaxError('/Length is undefined: %r' % dic)
objlen = 0
self.seek(pos)
try:
(_, line) = self.nextline() # 'stream'
except PSEOF:
if STRICT:
raise PDFSyntaxError('Unexpected EOF')
return
pos += len(line)
self.fp.seek(pos)
data = self.fp.read(objlen)
self.seek(pos+objlen)
while 1:
try:
(linepos, line) = self.nextline()
except PSEOF:
if STRICT:
raise PDFSyntaxError('Unexpected EOF')
break
if 'endstream' in line:
i = line.index('endstream')
objlen += i
data += line[:i]
break
objlen += len(line)
data += line
self.seek(pos+objlen)
obj = PDFStream(dic, data, self.doc.decipher)
self.push((pos, obj))
return
# others
self.push((pos, token))
return
def find_xref(self):
# search the last xref table by scanning the file backwards.
prev = None
for line in self.revreadlines():
line = line.strip()
if line == 'startxref': break
if line:
prev = line
else:
raise PDFNoValidXRef('Unexpected EOF')
return int(prev)
# read xref table
def read_xref_from(self, start, xrefs):
self.seek(start)
self.reset()
try:
(pos, token) = self.nexttoken()
except PSEOF:
raise PDFNoValidXRef('Unexpected EOF')
if isinstance(token, int):
# XRefStream: PDF-1.5
if GEN_XREF_STM == 1:
global gen_xref_stm
gen_xref_stm = True
self.seek(pos)
self.reset()
xref = PDFXRefStream()
xref.load(self)
else:
if token is not self.KEYWORD_XREF:
raise PDFNoValidXRef('xref not found: pos=%d, token=%r' %
(pos, token))
self.nextline()
xref = PDFXRef()
xref.load(self)
xrefs.append(xref)
trailer = xref.trailer
if 'XRefStm' in trailer:
pos = int_value(trailer['XRefStm'])
self.read_xref_from(pos, xrefs)
if 'Prev' in trailer:
# find previous xref
pos = int_value(trailer['Prev'])
self.read_xref_from(pos, xrefs)
return
# read xref tables and trailers
def read_xref(self):
xrefs = []
trailerpos = None
try:
pos = self.find_xref()
self.read_xref_from(pos, xrefs)
except PDFNoValidXRef:
# fallback
self.seek(0)
pat = re.compile(r'^(\d+)\s+(\d+)\s+obj\b')
offsets = {}
xref = PDFXRef()
while 1:
try:
(pos, line) = self.nextline()
except PSEOF:
break
if line.startswith('trailer'):
trailerpos = pos # remember last trailer
m = pat.match(line)
if not m: continue
(objid, genno) = m.groups()
offsets[int(objid)] = (0, pos)
if not offsets: raise
xref.offsets = offsets
if trailerpos:
self.seek(trailerpos)
xref.load_trailer(self)
xrefs.append(xref)
return xrefs
## PDFObjStrmParser
##
class PDFObjStrmParser(PDFParser):
def __init__(self, data, doc):
PSStackParser.__init__(self, StringIO(data))
self.doc = doc
return
def flush(self):
self.add_results(*self.popall())
return
KEYWORD_R = KWD('R')
def do_keyword(self, pos, token):
if token is self.KEYWORD_R:
# reference to indirect object
try:
((_,objid), (_,genno)) = self.pop(2)
(objid, genno) = (int(objid), int(genno))
obj = PDFObjRef(self.doc, objid, genno)
self.push((pos, obj))
except PSSyntaxError:
pass
return
# others
self.push((pos, token))
return
###
### My own code, for which there is none else to blame
class PDFSerializer(object):
def __init__(self, inf, userkey):
global GEN_XREF_STM, gen_xref_stm
gen_xref_stm = GEN_XREF_STM > 1
self.version = inf.read(8)
inf.seek(0)
self.doc = doc = PDFDocument()
parser = PDFParser(doc, inf)
doc.initialize(userkey)
self.objids = objids = set()
for xref in reversed(doc.xrefs):
trailer = xref.trailer
for objid in xref.objids():
objids.add(objid)
trailer = dict(trailer)
trailer.pop('Prev', None)
trailer.pop('XRefStm', None)
if 'Encrypt' in trailer:
objids.remove(trailer.pop('Encrypt').objid)
self.trailer = trailer
def dump(self, outf):
self.outf = outf
self.write(self.version)
self.write('\n%\xe2\xe3\xcf\xd3\n')
doc = self.doc
objids = self.objids
xrefs = {}
maxobj = max(objids)
trailer = dict(self.trailer)
trailer['Size'] = maxobj + 1
for objid in objids:
obj = doc.getobj(objid)
if isinstance(obj, PDFObjStmRef):
xrefs[objid] = obj
continue
if obj is not None:
try:
genno = obj.genno
except AttributeError:
genno = 0
xrefs[objid] = (self.tell(), genno)
self.serialize_indirect(objid, obj)
startxref = self.tell()
if not gen_xref_stm:
self.write('xref\n')
self.write('0 %d\n' % (maxobj + 1,))
for objid in range(0, maxobj + 1):
if objid in xrefs:
# force the genno to be 0
self.write("%010d 00000 n \n" % xrefs[objid][0])
else:
self.write("%010d %05d f \n" % (0, 65535))
self.write('trailer\n')
self.serialize_object(trailer)
self.write('\nstartxref\n%d\n%%%%EOF' % startxref)
else: # Generate crossref stream.
# Calculate size of entries
maxoffset = max(startxref, maxobj)
maxindex = PDFObjStmRef.maxindex
fl2 = 2
power = 65536
while maxoffset >= power:
fl2 += 1
power *= 256
fl3 = 1
power = 256
while maxindex >= power:
fl3 += 1
power *= 256
index = []
first = None
prev = None
data = []
# Put the xrefstream's reference in itself
startxref = self.tell()
maxobj += 1
xrefs[maxobj] = (startxref, 0)
for objid in sorted(xrefs):
if first is None:
first = objid
elif objid != prev + 1:
index.extend((first, prev - first + 1))
first = objid
prev = objid
objref = xrefs[objid]
if isinstance(objref, PDFObjStmRef):
f1 = 2
f2 = objref.stmid
f3 = objref.index
else:
f1 = 1
f2 = objref[0]
# we force all generation numbers to be 0
# f3 = objref[1]
f3 = 0
data.append(struct.pack('>B', f1))
data.append(struct.pack('>L', f2)[-fl2:])
data.append(struct.pack('>L', f3)[-fl3:])
index.extend((first, prev - first + 1))
data = zlib.compress(''.join(data))
dic = {'Type': LITERAL_XREF, 'Size': prev + 1, 'Index': index,
'W': [1, fl2, fl3], 'Length': len(data),
'Filter': LITERALS_FLATE_DECODE[0],
'Root': trailer['Root'],}
if 'Info' in trailer:
dic['Info'] = trailer['Info']
xrefstm = PDFStream(dic, data)
self.serialize_indirect(maxobj, xrefstm)
self.write('startxref\n%d\n%%%%EOF' % startxref)
def write(self, data):
self.outf.write(data)
self.last = data[-1:]
def tell(self):
return self.outf.tell()
def escape_string(self, string):
string = string.replace('\\', '\\\\')
string = string.replace('\n', r'\n')
string = string.replace('(', r'\(')
string = string.replace(')', r'\)')
# get rid of ciando id
regularexp = re.compile(r'http://www.ciando.com/index.cfm/intRefererID/\d{5}')
if regularexp.match(string): return ('http://www.ciando.com')
return string
def serialize_object(self, obj):
if isinstance(obj, dict):
# Correct malformed Mac OS resource forks for Stanza
if 'ResFork' in obj and 'Type' in obj and 'Subtype' not in obj \
and isinstance(obj['Type'], int):
obj['Subtype'] = obj['Type']
del obj['Type']
# end - hope this doesn't have bad effects
self.write('<<')
for key, val in obj.items():
self.write('/%s' % key)
self.serialize_object(val)
self.write('>>')
elif isinstance(obj, list):
self.write('[')
for val in obj:
self.serialize_object(val)
self.write(']')
elif isinstance(obj, str):
self.write('(%s)' % self.escape_string(obj))
elif isinstance(obj, bool):
if self.last.isalnum():
self.write(' ')
self.write(str(obj).lower())
elif isinstance(obj, int):
if self.last.isalnum():
self.write(' ')
self.write(str(obj))
elif isinstance(obj, Decimal):
if self.last.isalnum():
self.write(' ')
self.write(str(obj))
elif isinstance(obj, PDFObjRef):
if self.last.isalnum():
self.write(' ')
self.write('%d %d R' % (obj.objid, 0))
elif isinstance(obj, PDFStream):
### If we don't generate cross ref streams the object streams
### are no longer useful, as we have extracted all objects from
### them. Therefore leave them out from the output.
if obj.dic.get('Type') == LITERAL_OBJSTM and not gen_xref_stm:
self.write('(deleted)')
else:
data = obj.get_decdata()
self.serialize_object(obj.dic)
self.write('stream\n')
self.write(data)
self.write('\nendstream')
else:
data = str(obj)
if data[0].isalnum() and self.last.isalnum():
self.write(' ')
self.write(data)
def serialize_indirect(self, objid, obj):
self.write('%d 0 obj' % (objid,))
self.serialize_object(obj)
if self.last.isalnum():
self.write('\n')
self.write('endobj\n')
def decryptBook(userkey, inpath, outpath):
if RSA is None:
raise ADEPTError(u"PyCrypto or OpenSSL must be installed.")
with open(inpath, 'rb') as inf:
#try:
serializer = PDFSerializer(inf, userkey)
#except:
# print u"Error serializing pdf {0}. Probably wrong key.".format(os.path.basename(inpath))
# return 2
# hope this will fix the 'bad file descriptor' problem
with open(outpath, 'wb') as outf:
# help construct to make sure the method runs to the end
try:
serializer.dump(outf)
except Exception as e:
print(u"error writing pdf: {0}".format(e.args[0]))
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(u"usage: {0} <keyfile.der> <inbook.pdf> <outbook.pdf>".format(progname))
return 1
keypath, inpath, outpath = argv[1:]
userkey = open(keypath,'rb').read()
result = decryptBook(userkey, inpath, outpath)
if result == 0:
print(u"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 Tkconstants
import tkFileDialog
import tkMessageBox
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=u"Select files for decryption")
self.status.pack(fill=Tkconstants.X, expand=1)
body = Tkinter.Frame(self)
body.pack(fill=Tkconstants.X, expand=1)
sticky = Tkconstants.E + Tkconstants.W
body.grid_columnconfigure(1, weight=2)
Tkinter.Label(body, text=u"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(u"adeptkey.der"):
self.keypath.insert(0, u"adeptkey.der")
button = Tkinter.Button(body, text=u"...", command=self.get_keypath)
button.grid(row=0, column=2)
Tkinter.Label(body, text=u"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=u"...", command=self.get_inpath)
button.grid(row=1, column=2)
Tkinter.Label(body, text=u"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=u"...", command=self.get_outpath)
button.grid(row=2, column=2)
buttons = Tkinter.Frame(self)
buttons.pack()
botton = Tkinter.Button(
buttons, text=u"Decrypt", width=10, command=self.decrypt)
botton.pack(side=Tkconstants.LEFT)
Tkinter.Frame(buttons, width=10).pack(side=Tkconstants.LEFT)
button = Tkinter.Button(
buttons, text=u"Quit", width=10, command=self.quit)
button.pack(side=Tkconstants.RIGHT)
def get_keypath(self):
keypath = tkFileDialog.askopenfilename(
parent=None, title=u"Select Adobe Adept \'.der\' key file",
defaultextension=u".der",
filetypes=[('Adobe Adept DER-encoded files', '.der'),
('All Files', '.*')])
if keypath:
keypath = os.path.normpath(keypath)
self.keypath.delete(0, Tkconstants.END)
self.keypath.insert(0, keypath)
return
def get_inpath(self):
inpath = tkFileDialog.askopenfilename(
parent=None, title=u"Select ADEPT-encrypted PDF file to decrypt",
defaultextension=u".pdf", filetypes=[('PDF files', '.pdf')])
if inpath:
inpath = os.path.normpath(inpath)
self.inpath.delete(0, Tkconstants.END)
self.inpath.insert(0, inpath)
return
def get_outpath(self):
outpath = tkFileDialog.asksaveasfilename(
parent=None, title=u"Select unencrypted PDF file to produce",
defaultextension=u".pdf", filetypes=[('PDF files', '.pdf')])
if outpath:
outpath = os.path.normpath(outpath)
self.outpath.delete(0, Tkconstants.END)
self.outpath.insert(0, outpath)
return
def decrypt(self):
keypath = self.keypath.get()
inpath = self.inpath.get()
outpath = self.outpath.get()
if not keypath or not os.path.exists(keypath):
self.status['text'] = u"Specified key file does not exist"
return
if not inpath or not os.path.exists(inpath):
self.status['text'] = u"Specified input file does not exist"
return
if not outpath:
self.status['text'] = u"Output file not specified"
return
if inpath == outpath:
self.status['text'] = u"Must have different input and output files"
return
userkey = open(keypath,'rb').read()
self.status['text'] = u"Decrypting..."
try:
decrypt_status = decryptBook(userkey, inpath, outpath)
except Exception as e:
self.status['text'] = u"Error; {0}".format(e.args[0])
return
if decrypt_status == 0:
self.status['text'] = u"File successfully decrypted"
else:
self.status['text'] = u"The was an error decrypting the file."
root = Tkinter.Tk()
if RSA is None:
root.withdraw()
tkMessageBox.showerror(
"INEPT PDF",
"This script requires OpenSSL or PyCrypto, which must be installed "
"separately. Read the top-of-script comment for details.")
return 1
root.title(u"Adobe Adept PDF Decrypter v.{0}".format(__version__))
root.resizable(True, False)
root.minsize(370, 0)
DecryptionDialog(root).pack(fill=Tkconstants.X, expand=1)
root.mainloop()
return 0
if __name__ == '__main__':
if len(sys.argv) > 1:
sys.exit(cli_main())
sys.exit(gui_main())
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