From a180fcacb2528b0d15cbb6cea9e825658e3871d5 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?i=E2=99=A5cabbages?= Date: Thu, 9 Jul 2009 14:03:43 +0100 Subject: [PATCH] ineptpdf v2 --- ineptpdf.pyw | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) diff --git a/ineptpdf.pyw b/ineptpdf.pyw index 1599ad7..65455e9 100644 --- a/ineptpdf.pyw +++ b/ineptpdf.pyw @@ -1,6 +1,6 @@ #! /usr/bin/python -# ineptpdf.pyw, version 1 +# ineptpdf.pyw, version 2 # To run this program install Python 2.6 from http://www.python.org/download/ # and PyCrypto from http://www.voidspace.org.uk/python/modules.shtml#pycrypto @@ -9,6 +9,7 @@ # Revision history: # 1 - Initial release +# 2 - Improved determination of key-generation algorithm """ Decrypt Adobe ADEPT-encrypted PDF files. @@ -1013,7 +1014,6 @@ class PDFDocument(object): raise PDFEncryptionError('Unknown filter: param=%r' % param) def initialize_ebx(self, password, docid, param): - V = int_value(param.get('V', 0)) self.is_printable = self.is_modifiable = self.is_extractable = True with open(password, 'rb') as f: keyder = f.read() @@ -1030,14 +1030,15 @@ class PDFDocument(object): if bookkey[0] != '\x02': raise ADEPTError('error decrypting book session key') index = bookkey.index('\0') + 1 - if V == 3: - if bookkey[index] != '\x03': - raise ADEPTError('error decrypting book session key') - index += 1 bookkey = bookkey[index:] - if len(bookkey) != length: + V = 2 + if (length and len(bookkey) == (length + 1)) or \ + (not length and len(bookkey) & 1 == 1): + V = ord(bookkey[0]) + bookkey = bookkey[1:] + if length and len(bookkey) != length: raise ADEPTError('error decrypting book session key') - self.decrypt_key = bookkey[-length:] + self.decrypt_key = bookkey self.genkey = self.genkey_v3 if V == 3 else self.genkey_v2 self.decipher = self.decrypt_rc4 self.ready = True