DeDRM_tools/Other_Tools/Adobe_PDF_Tools/ineptpdf.pyw

#! /usr/bin/env python
# ineptpdf.pyw, version 7.9

from __future__ import with_statement

# To run this program install Python 2.6 from http://www.python.org/download/
# and OpenSSL (already installed on Mac OS X and Linux) OR 
# PyCrypto from http://www.voidspace.org.uk/python/modules.shtml#pycrypto
# (make sure to install the version for Python 2.6).  Save this script file as
# ineptpdf.pyw and double-click on it to run it.

# 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

"""
Decrypts Adobe ADEPT-encrypted PDF files.
"""

__license__ = 'GPL v3'

import sys
import os
import re
import zlib
import struct
import hashlib
from itertools import chain, islice
import xml.etree.ElementTree as etree
import Tkinter
import Tkconstants
import tkFileDialog
import tkMessageBox

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):
        @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 xrange(1, 4)]
            key = [self.bytesToNumber(v) for v in key]
            self._rsa = _RSA.construct(key)

        def bytesToNumber(self, bytes):
            total = 0L
            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:
    from StringIO 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 ord(s)
    elif l == 2:
        return struct.unpack('>H', s)[0]
    elif l == 3:
        return struct.unpack('>L', '\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 = '#%02x' % ord(char)
            name.append(char)
        return '/%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_float, 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_float, j+1)
        try:
            self.add_token(int(self.token))
        except ValueError:
            pass
        return (self.parse_main, j)
    def parse_float(self, s, i):
        m = END_NUMBER.search(s, i)
        if not m:
            self.token += s[i:]
            return (self.parse_float, len(s))
        j = m.start(0)
        self.token += s[i:j]
        self.add_token(float(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, float) 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:
                        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 float_value(x):
    x = resolve1(x)
    if not isinstance(x, float):
        if STRICT:
            raise PDFTypeError('Float required: %r' % x)
        return 0.0
    return x

def num_value(x):
    x = resolve1(x)
    if not (isinstance(x, int) or isinstance(x, float)):
        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 = ''
  for c in data:
    if '!' <= c and c <= 'u':
      n += 1
      b = b*85+(ord(c)-33)
      if n == 5:
        out += struct.pack('>L',b)
        n = b = 0
    elif c == 'z':
      assert n == 0
      out += '\0\0\0\0'
    elif c == '~':
      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 ('\r', '\n', '\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 = ''
                    ent0 = '\x00' * columns
                    for i in xrange(0, len(data), columns+1):
                        pred = data[i]
                        ent1 = data[i+1:i+1+columns]
                        if pred == '\x02':
                            ent1 = ''.join(chr((ord(a)+ord(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 xrange(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 xrange(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(islice(index, 0, None, 2),
                         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
            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 ord(pdrlpol[-1]) < 1 or ord(pdrlpol[-1]) > 16:
            raise ADEPTError('Could not decrypt PDRLPol, aborting ...')
        else:
            cutter = -1 * ord(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 xrange(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 xrange(1,19+1):
                k = ''.join( chr(ord(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:
            elf.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
        with open(password, 'rb') as f:
            keyder = f.read()
        rsa = RSA(keyder)
        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 = ord(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" % ord(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" % ord(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 * ord(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 * ord(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, keypath):
        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(keypath)
        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 xrange(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, long, float)):
            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')


class DecryptionDialog(Tkinter.Frame):
    def __init__(self, root):
        Tkinter.Frame.__init__(self, root, border=5)
        ltext='Select file for decryption\n'        
        self.status = Tkinter.Label(self, text=ltext)
        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='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=Tkconstants.LEFT)
        Tkinter.Frame(buttons, width=10).pack(side=Tkconstants.LEFT)
        button = Tkinter.Button(
            buttons, text="Quit", width=10, command=self.quit)
        button.pack(side=Tkconstants.RIGHT)
         

    def get_keypath(self):
        keypath = tkFileDialog.askopenfilename(
            parent=None, title='Select ADEPT key file',
            defaultextension='.der', filetypes=[('DER-encoded files', '.der'),
                                                ('All Files', '.*')])
        if keypath:
            keypath = os.path.normpath(os.path.realpath(keypath))
            self.keypath.delete(0, Tkconstants.END)
            self.keypath.insert(0, keypath)
        return

    def get_inpath(self):
        inpath = tkFileDialog.askopenfilename(
            parent=None, title='Select ADEPT encrypted PDF file to decrypt',
            defaultextension='.pdf', filetypes=[('PDF files', '.pdf'),
                                                 ('All files', '.*')])
        if inpath:
            inpath = os.path.normpath(os.path.realpath(inpath))
            self.inpath.delete(0, Tkconstants.END)
            self.inpath.insert(0, inpath)
        return

    def get_outpath(self):
        outpath = tkFileDialog.asksaveasfilename(
            parent=None, title='Select unencrypted PDF file to produce',
            defaultextension='.pdf', filetypes=[('PDF files', '.pdf'),
                                                 ('All files', '.*')])
        if outpath:
            outpath = os.path.normpath(os.path.realpath(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):
            # keyfile doesn't exist
            self.status['text'] = 'Specified Adept 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
        # patch for non-ascii characters
        argv = [sys.argv[0], keypath, inpath, outpath]
        self.status['text'] = 'Processing ...'
        try:
            cli_main(argv)
        except Exception, a:
            self.status['text'] = 'Error: ' + str(a)
            return
        self.status['text'] = 'File successfully decrypted.\n'+\
                              'Close this window or decrypt another pdf file.'
        return


def decryptBook(keypath, inpath, outpath):
    with open(inpath, 'rb') as inf:
        serializer = PDFSerializer(inf, keypath)
        # 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
            serializer.dump(outf)
    return 0


def cli_main(argv=sys.argv):
    progname = os.path.basename(argv[0])
    if RSA is None:
        print "%s: This script requires OpenSSL or PyCrypto, which must be installed " \
              "separately.  Read the top-of-script comment for details." % \
              (progname,)
        return 1
    if len(argv) != 4:
        print "usage: %s KEYFILE INBOOK OUTBOOK" % (progname,)
        return 1
    keypath, inpath, outpath = argv[1:]
    return decryptBook(keypath, inpath, outpath)


def gui_main():
    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('INEPT PDF Decrypter')
    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())