Fix PDF corruption in Calibre 4 (#104)

Apparently "import_key" only exists in newer versions (as an alias to
"importKey"). "importKey" works in all versions ...

CHANGELOG.md

@@ -69,4 +69,8 @@ List of changes since the fork of Apprentice Harper's repository:
 
 ## Fixes on master (not yet released):
 
-- (None)
+- Fix a bug introduced with #48 that breaks DeDRM'ing on Calibre 4 (fixes #101).
+- Fix some more Calibre-6 bugs in the Obok plugin (should fix #114).
+- Fix a bug where invalid Adobe keys could cause the plugin to stop trying subsequent keys (partially fixes #109).
+- Fix DRM removal sometimes resetting the ZIP's internal "external_attr" value on Calibre 5 and newer.
+- Fix PDF decryption issues on Calibre 4 (hopefully fixes #104).

DeDRM_plugin/__init__.py

@@ -511,10 +511,10 @@ class DeDRM(FileTypePlugin):
                             continue
 
                         # Found matching key
-                        userkey = codecs.decode(userkeyhex, 'hex')
                         print("{0} v{1}: Trying UUID-matched encryption key {2:s}".format(PLUGIN_NAME, PLUGIN_VERSION, keyname))
                         of = self.temporary_file(".epub")
                         try: 
+                            userkey = codecs.decode(userkeyhex, 'hex')
                             result = ineptepub.decryptBook(userkey, inf.name, of.name)
                             of.close()
                             if result == 0:
@@ -531,12 +531,13 @@ class DeDRM(FileTypePlugin):
 
                 # Attempt to decrypt epub with each encryption key (generated or provided).
                 for keyname, userkeyhex in dedrmprefs['adeptkeys'].items():
-                    userkey = codecs.decode(userkeyhex, 'hex')
+                    
                     print("{0} v{1}: Trying Encryption key {2:s}".format(PLUGIN_NAME, PLUGIN_VERSION, keyname))
                     of = self.temporary_file(".epub")
 
                     # Give the user key, ebook and TemporaryPersistent file to the decryption function.
                     try:
+                        userkey = codecs.decode(userkeyhex, 'hex')
                         result = ineptepub.decryptBook(userkey, inf.name, of.name)
                     except ineptepub.ADEPTNewVersionError:
                         print("{0} v{1}: Book uses unsupported (too new) Adobe DRM.".format(PLUGIN_NAME, PLUGIN_VERSION, time.time()-self.starttime))
@@ -673,11 +674,11 @@ class DeDRM(FileTypePlugin):
                     continue
             
                 # Found matching key
-                userkey = codecs.decode(userkeyhex, 'hex')
                 print("{0} v{1}: Trying UUID-matched encryption key {2:s}".format(PLUGIN_NAME, PLUGIN_VERSION, keyname))
                 of = self.temporary_file(".pdf")
 
                 try: 
+                    userkey = codecs.decode(userkeyhex, 'hex')
                     result = ineptpdf.decryptBook(userkey, path_to_ebook, of.name)
                     of.close()
                     if result == 0:

DeDRM_plugin/epubfontdecrypt.py

@@ -25,6 +25,7 @@ import traceback
 import zlib
 import zipfile
 from zipfile import ZipInfo, ZipFile, ZIP_STORED, ZIP_DEFLATED
+from zeroedzipinfo import ZeroedZipInfo
 from contextlib import closing
 from lxml import etree
 import itertools
@@ -298,13 +299,21 @@ def decryptFontsBook(inpath, outpath):
                         zi.internal_attr = oldzi.internal_attr
                         # external attributes are dependent on the create system, so copy both.
                         zi.external_attr = oldzi.external_attr
+                        zi.volume = oldzi.volume
                         zi.create_system = oldzi.create_system
+                        zi.create_version = oldzi.create_version
+
                         if any(ord(c) >= 128 for c in path) or any(ord(c) >= 128 for c in zi.comment):
                             # If the file name or the comment contains any non-ASCII char, set the UTF8-flag
                             zi.flag_bits |= 0x800
                     except:
                         pass
 
+                    # Python 3 has a bug where the external_attr is reset to `0o600 << 16`
+                    # if it's NULL, so we need a workaround:
+                    if zi.external_attr == 0: 
+                        zi = ZeroedZipInfo(zi)
+
                     if path == "mimetype":
                         outf.writestr(zi, inf.read('mimetype'))
                     elif path == "META-INF/encryption.xml":

DeDRM_plugin/epubwatermark.py

@@ -16,6 +16,7 @@ Removes various watermarks from EPUB files
 
 import traceback
 from zipfile import ZipInfo, ZipFile, ZIP_STORED, ZIP_DEFLATED
+from zeroedzipinfo import ZeroedZipInfo
 from contextlib import closing
 from lxml import etree
 import re
@@ -133,13 +134,22 @@ def removeHTMLwatermarks(object, path_to_ebook):
                         zi.extra = oldzi.extra
                         zi.internal_attr = oldzi.internal_attr
                         zi.external_attr = oldzi.external_attr
+                        zi.volume = oldzi.volume
                         zi.create_system = oldzi.create_system
+                        zi.create_version = oldzi.create_version
+
                         if any(ord(c) >= 128 for c in path) or any(ord(c) >= 128 for c in zi.comment):
                             # If the file name or the comment contains any non-ASCII char, set the UTF8-flag
                             zi.flag_bits |= 0x800
                     except:
                         pass
 
+                    # Python 3 has a bug where the external_attr is reset to `0o600 << 16`
+                    # if it's NULL, so we need a workaround:
+                    if zi.external_attr == 0: 
+                        zi = ZeroedZipInfo(zi)
+
+
                     outf.writestr(zi, data)
         except:
             traceback.print_exc()
@@ -249,13 +259,21 @@ def removeOPFwatermarks(object, path_to_ebook):
                         zi.extra = oldzi.extra
                         zi.internal_attr = oldzi.internal_attr
                         zi.external_attr = oldzi.external_attr
+                        zi.volume = oldzi.volume
                         zi.create_system = oldzi.create_system
+                        zi.create_version = oldzi.create_version
+
                         if any(ord(c) >= 128 for c in path) or any(ord(c) >= 128 for c in zi.comment):
                             # If the file name or the comment contains any non-ASCII char, set the UTF8-flag
                             zi.flag_bits |= 0x800
                     except:
                         pass
 
+                    # Python 3 has a bug where the external_attr is reset to `0o600 << 16`
+                    # if it's NULL, so we need a workaround:
+                    if zi.external_attr == 0: 
+                        zi = ZeroedZipInfo(zi)
+
                     outf.writestr(zi, data)
         except:
             traceback.print_exc()
@@ -301,13 +319,21 @@ def removeCDPwatermark(object, path_to_ebook):
                     zi.extra = oldzi.extra
                     zi.internal_attr = oldzi.internal_attr
                     zi.external_attr = oldzi.external_attr
+                    zi.volume = oldzi.volume
                     zi.create_system = oldzi.create_system
+                    zi.create_version = oldzi.create_version
+
                     if any(ord(c) >= 128 for c in path) or any(ord(c) >= 128 for c in zi.comment):
                         # If the file name or the comment contains any non-ASCII char, set the UTF8-flag
                         zi.flag_bits |= 0x800
                 except:
                     pass
 
+                # Python 3 has a bug where the external_attr is reset to `0o600 << 16`
+                # if it's NULL, so we need a workaround:
+                if zi.external_attr == 0: 
+                    zi = ZeroedZipInfo(zi)
+
                 outf.writestr(zi, data)
         
         print("Watermark: Successfully removed cdp.info watermark")

DeDRM_plugin/ineptepub.py

@@ -48,6 +48,7 @@ import base64
 import zlib
 import zipfile
 from zipfile import ZipInfo, ZipFile, ZIP_STORED, ZIP_DEFLATED
+from zeroedzipinfo import ZeroedZipInfo
 from contextlib import closing
 from lxml import etree
 from uuid import UUID
@@ -302,7 +303,7 @@ def decryptBook(userkey, inpath, outpath):
 
             if len(bookkey) != 64:
                 # Normal or "hardened" Adobe ADEPT
-                rsakey = RSA.import_key(userkey) # parses the ASN1 structure
+                rsakey = RSA.importKey(userkey) # parses the ASN1 structure
                 bookkey = base64.b64decode(bookkey)
                 if int(keytype, 10) > 2:
                     bookkey = removeHardening(rights, keytype, bookkey)
@@ -356,12 +357,23 @@ def decryptBook(userkey, inpath, outpath):
                         zi.internal_attr = oldzi.internal_attr
                         # external attributes are dependent on the create system, so copy both.
                         zi.external_attr = oldzi.external_attr
+
+                        zi.volume = oldzi.volume
                         zi.create_system = oldzi.create_system
+                        zi.create_version = oldzi.create_version
+
                         if any(ord(c) >= 128 for c in path) or any(ord(c) >= 128 for c in zi.comment):
                             # If the file name or the comment contains any non-ASCII char, set the UTF8-flag
                             zi.flag_bits |= 0x800
                     except:
                         pass
+
+                    # Python 3 has a bug where the external_attr is reset to `0o600 << 16`
+                    # if it's NULL, so we need a workaround:
+                    if zi.external_attr == 0: 
+                        zi = ZeroedZipInfo(zi)
+
+
                     if path == "META-INF/encryption.xml":
                         outf.writestr(zi, data)
                     else:

DeDRM_plugin/ineptpdf.py

@@ -51,13 +51,14 @@
 #   9.1.1 - Only support PyCryptodome; clean up the code
 #   10.0.0 - Add support for "hardened" Adobe DRM (RMSDK >= 10)
 #   10.0.2 - Fix some Python2 stuff
+#   10.0.4 - Fix more Python2 stuff
 
 """
 Decrypts Adobe ADEPT-encrypted PDF files.
 """
 
 __license__ = 'GPL v3'
-__version__ = "10.0.2"
+__version__ = "10.0.4"
 
 import codecs
 import hashlib
@@ -200,7 +201,10 @@ def nunpack(s, default=0):
     elif l == 2:
         return struct.unpack('>H', s)[0]
     elif l == 3:
-        return struct.unpack('>L', bytes([0]) + s)[0]
+        if sys.version_info[0] == 2:
+            return struct.unpack('>L', '\x00'+s)[0]
+        else: 
+            return struct.unpack('>L', bytes([0]) + s)[0]
     elif l == 4:
         return struct.unpack('>L', s)[0]
     else:
@@ -459,7 +463,10 @@ class PSBaseParser(object):
             self.hex += c
             return (self.parse_literal_hex, i+1)
         if self.hex:
-            self.token += bytes([int(self.hex, 16)])
+            if sys.version_info[0] == 2: 
+                self.token += chr(int(self.hex, 16))
+            else: 
+                self.token += bytes([int(self.hex, 16)])
         return (self.parse_literal, i)
 
     def parse_number(self, s, i):
@@ -543,10 +550,18 @@ class PSBaseParser(object):
             self.oct += c
             return (self.parse_string_1, i+1)
         if self.oct:
-            self.token += bytes([int(self.oct, 8)])
+            if sys.version_info[0] == 2:
+                self.token += chr(int(self.oct, 8))
+            else: 
+                self.token += bytes([int(self.oct, 8)])  
             return (self.parse_string, i)
         if c in ESC_STRING:
-            self.token += bytes([ESC_STRING[c]])
+
+            if sys.version_info[0] == 2:
+                self.token += chr(ESC_STRING[c])
+            else: 
+                self.token += bytes([ESC_STRING[c]])
+                
         return (self.parse_string, i+1)
 
     def parse_wopen(self, s, i):
@@ -572,14 +587,19 @@ class PSBaseParser(object):
         return (self.parse_main, i)
 
     def parse_hexstring(self, s, i):
-        m1 = END_HEX_STRING.search(s, i)
+        m = END_HEX_STRING.search(s, i)
-        if not m1:
+        if not m:
             self.token += s[i:]
             return (self.parse_hexstring, len(s))
-        j = m1.start(0)
+        j = m.start(0)
         self.token += s[i:j]
-        token = HEX_PAIR.sub(lambda m2: bytes([int(m2.group(0), 16)]),
+        if sys.version_info[0] == 2:
+            token = HEX_PAIR.sub(lambda m: chr(int(m.group(0), 16)),
+                                                 SPC.sub('', self.token))
+        else: 
+            token = HEX_PAIR.sub(lambda m: bytes([int(m.group(0), 16)]),
                                                  SPC.sub(b'', self.token))
+
         self.add_token(token)
         return (self.parse_main, j)
 
@@ -1669,7 +1689,7 @@ class PDFDocument(object):
 
     def initialize_ebx_inept(self, password, docid, param):
         self.is_printable = self.is_modifiable = self.is_extractable = True
-        rsakey = RSA.import_key(password) # parses the ASN1 structure
+        rsakey = RSA.importKey(password) # parses the ASN1 structure
         length = int_value(param.get('Length', 0)) // 8
         rights = codecs.decode(param.get('ADEPT_LICENSE'), 'base64')
         rights = zlib.decompress(rights, -15)

DeDRM_plugin/zeroedzipinfo.py

@@ -0,0 +1,30 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+
+
+"""
+Python 3's "zipfile" has an annoying bug where the `external_attr` field 
+of a ZIP file cannot be set to 0. However, if the original DRMed ZIP has 
+that set to 0 then we want the DRM-free ZIP to have that as 0, too. 
+See https://github.com/python/cpython/issues/87713
+
+We cannot just set the "external_attr" to 0 as the code to save the ZIP
+resets that variable. 
+
+So, here's a class that inherits from ZipInfo and ensures that EVERY 
+read access to that variable will return a 0 ...
+
+"""
+
+import zipfile
+
+class ZeroedZipInfo(zipfile.ZipInfo):
+    def __init__(self, zinfo):
+        for k in self.__slots__:
+            if hasattr(zinfo, k):
+                setattr(self, k, getattr(zinfo, k))
+
+    def __getattribute__(self, name):
+        if name == "external_attr":
+            return 0
+        return object.__getattribute__(self, name)

DeDRM_plugin/zipfilerugged.py

@@ -394,6 +394,19 @@ class ZipInfo (object):
             extra = extra[ln+4:]
 
 
+class ZeroedZipInfo(ZipInfo):
+    def __init__(self, zinfo):
+        for k in self.__slots__:
+            if hasattr(zinfo, k):
+                setattr(self, k, getattr(zinfo, k))
+
+    def __getattribute__(self, name):
+        if name == "external_attr":
+            return 0
+        return object.__getattribute__(self, name)
+
+
+
 class _ZipDecrypter:
     """Class to handle decryption of files stored within a ZIP archive.
 

DeDRM_plugin/zipfix.py

@@ -26,6 +26,7 @@ import sys, os
 
 import zlib
 import zipfilerugged
+from zipfilerugged import ZipInfo, ZeroedZipInfo
 import getopt
 from struct import unpack
 
@@ -36,12 +37,6 @@ _FILENAME_OFFSET = 30
 _MAX_SIZE = 64 * 1024
 _MIMETYPE = 'application/epub+zip'
 
-class ZipInfo(zipfilerugged.ZipInfo):
-    def __init__(self, *args, **kwargs):
-        if 'compress_type' in kwargs:
-            compress_type = kwargs.pop('compress_type')
-        super(ZipInfo, self).__init__(*args, **kwargs)
-        self.compress_type = compress_type
 
 class fixZip:
     def __init__(self, zinput, zoutput):
@@ -117,7 +112,8 @@ class fixZip:
         # if epub write mimetype file first, with no compression
         if self.ztype == 'epub':
             # first get a ZipInfo with current time and no compression
-            mimeinfo = ZipInfo(b'mimetype',compress_type=zipfilerugged.ZIP_STORED)
+            mimeinfo = ZipInfo(b'mimetype')
+            mimeinfo.compress_type = zipfilerugged.ZIP_STORED
             mimeinfo.internal_attr = 1 # text file
             try:
                 # if the mimetype is present, get its info, including time-stamp
@@ -129,8 +125,16 @@ class fixZip:
                 mimeinfo.internal_attr = oldmimeinfo.internal_attr
                 mimeinfo.external_attr = oldmimeinfo.external_attr
                 mimeinfo.create_system = oldmimeinfo.create_system
+                mimeinfo.create_version = oldmimeinfo.create_version
+                mimeinfo.volume = oldmimeinfo.volume
             except:
                 pass
+
+            # Python 3 has a bug where the external_attr is reset to `0o600 << 16`
+            # if it's NULL, so we need a workaround:
+            if mimeinfo.external_attr == 0: 
+                mimeinfo = ZeroedZipInfo(mimeinfo)
+
             self.outzip.writestr(mimeinfo, _MIMETYPE.encode('ascii'))
 
         # write the rest of the files
@@ -145,13 +149,23 @@ class fixZip:
                     zinfo.filename = local_name
 
                 # create new ZipInfo with only the useful attributes from the old info
-                nzinfo = ZipInfo(zinfo.filename, zinfo.date_time, compress_type=zinfo.compress_type)
+                nzinfo = ZipInfo(zinfo.filename)
+                nzinfo.date_time = zinfo.date_time
+                nzinfo.compress_type = zinfo.compress_type
                 nzinfo.comment=zinfo.comment
                 nzinfo.extra=zinfo.extra
                 nzinfo.internal_attr=zinfo.internal_attr
                 nzinfo.external_attr=zinfo.external_attr
                 nzinfo.create_system=zinfo.create_system
+                nzinfo.create_version = zinfo.create_version
+                nzinfo.volume = zinfo.volume
                 nzinfo.flag_bits = zinfo.flag_bits & 0x800  # preserve UTF-8 flag
+
+                # Python 3 has a bug where the external_attr is reset to `0o600 << 16`
+                # if it's NULL, so we need a workaround:
+                if nzinfo.external_attr == 0: 
+                    nzinfo = ZeroedZipInfo(nzinfo)
+
                 self.outzip.writestr(nzinfo,data)
 
         self.bzf.close()

Obok_plugin/common_utils.py

@@ -265,13 +265,13 @@ class ReadOnlyTableWidgetItem(QTableWidgetItem):
     def __init__(self, text):
         if text is None:
             text = ''
-        QTableWidgetItem.__init__(self, text, QTableWidgetItem.UserType)
+        QTableWidgetItem.__init__(self, text, QTableWidgetItem.ItemType.UserType)
         self.setFlags(Qt.ItemIsSelectable|Qt.ItemIsEnabled)
 
 class RatingTableWidgetItem(QTableWidgetItem):
 
     def __init__(self, rating, is_read_only=False):
-        QTableWidgetItem.__init__(self, '', QTableWidgetItem.UserType)
+        QTableWidgetItem.__init__(self, '', QTableWidgetItem.ItemType.UserType)
         self.setData(Qt.DisplayRole, rating)
         if is_read_only:
             self.setFlags(Qt.ItemIsSelectable|Qt.ItemIsEnabled)
@@ -284,11 +284,11 @@ class DateTableWidgetItem(QTableWidgetItem):
         if date_read is None or date_read == UNDEFINED_DATE and default_to_today:
             date_read = now()
         if is_read_only:
-            QTableWidgetItem.__init__(self, format_date(date_read, fmt), QTableWidgetItem.UserType)
+            QTableWidgetItem.__init__(self, format_date(date_read, fmt), QTableWidgetItem.ItemType.UserType)
             self.setFlags(Qt.ItemIsSelectable|Qt.ItemIsEnabled)
             self.setData(Qt.DisplayRole, QDateTime(date_read))
         else:
-            QTableWidgetItem.__init__(self, '', QTableWidgetItem.UserType)
+            QTableWidgetItem.__init__(self, '', QTableWidgetItem.ItemType.UserType)
             self.setData(Qt.DisplayRole, QDateTime(date_read))
 
 from calibre.gui2.library.delegates import DateDelegate as _DateDelegate

Obok_plugin/utilities.py

@@ -224,5 +224,5 @@ class ReadOnlyTableWidgetItem(QTableWidgetItem):
     def __init__(self, text):
         if text is None:
             text = ''
-        QTableWidgetItem.__init__(self, text, QTableWidgetItem.UserType)
+        QTableWidgetItem.__init__(self, text, QTableWidgetItem.ItemType.UserType)
         self.setFlags(Qt.ItemIsSelectable|Qt.ItemIsEnabled)