traceback.print_exc()
raise
+ def checkFonts(self, path_to_ebook):
+ # This is called after the normal DRM removal is done.
+ # It checks if there's fonts that need to be deobfuscated
+
+ import calibre_plugins.dedrm.prefs as prefs
+ dedrmprefs = prefs.DeDRM_Prefs()
+
+ if dedrmprefs["deobfuscate_fonts"] is True:
+ import calibre_plugins.dedrm.epubfontdecrypt as epubfontdecrypt
+
+ output = self.temporary_file(".epub").name
+ ret = epubfontdecrypt.decryptFontsBook(path_to_ebook, output)
+
+ if (ret == 0):
+ print("Font deobfuscation successful")
+ return output
+ elif (ret == 1):
+ print("No font obfuscation found")
+ return path_to_ebook
+ else:
+ print("Errors during font deobfuscation!")
+ raise DeDRMError("Font deobfuscation failed")
+ else:
+ return path_to_ebook
+
def ePubDecrypt(self,path_to_ebook):
# Create a TemporaryPersistent file to work with.
# Check original epub archive for zip errors.
if result == 0:
# Decryption was successful.
# Return the modified PersistentTemporary file to calibre.
- return of.name
+ return self.checkFonts(of.name)
print("{0} v{1}: Failed to decrypt with key {2:s} after {3:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION,keyname_masked,time.time()-self.starttime))
print("{0} v{1}: Exception saving a new default key after {2:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION, time.time()-self.starttime))
traceback.print_exc()
# Return the modified PersistentTemporary file to calibre.
- return of.name
+ return self.checkFonts(of.name)
print("{0} v{1}: Failed to decrypt with new default key after {2:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION,time.time()-self.starttime))
except Exception as e:
of.close()
if result == 0:
print("{0} v{1}: Decrypted with key {2:s} after {3:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION,keyname,time.time()-self.starttime))
- return of.name
+ return self.checkFonts(of.name)
except:
print("{0} v{1}: Exception when decrypting after {2:.1f} seconds - trying other keys".format(PLUGIN_NAME, PLUGIN_VERSION, time.time()-self.starttime))
traceback.print_exc()
# Decryption was successful.
# Return the modified PersistentTemporary file to calibre.
print("{0} v{1}: Decrypted with key {2:s} after {3:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION,keyname,time.time()-self.starttime))
- return of.name
+ return self.checkFonts(of.name)
print("{0} v{1}: Failed to decrypt with key {2:s} after {3:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION,keyname,time.time()-self.starttime))
traceback.print_exc()
print("{0} v{1}: Decrypted with new default key after {2:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION,time.time()-self.starttime))
# Return the modified PersistentTemporary file to calibre.
- return of.name
+ return self.checkFonts(of.name)
print("{0} v{1}: Failed to decrypt with new default key after {2:.1f} seconds".format(PLUGIN_NAME, PLUGIN_VERSION,time.time()-self.starttime))
except Exception as e:
raise DeDRMError("{0} v{1}: Ultimately failed to decrypt after {2:.1f} seconds. Read the FAQs at Harper's repository: https://github.com/apprenticeharper/DeDRM_tools/blob/master/FAQs.md".format(PLUGIN_NAME, PLUGIN_VERSION,time.time()-self.starttime))
# Not a Barnes & Noble nor an Adobe Adept
- # Import the fixed epub.
+ # Probably a DRM-free EPUB, but we should still check for fonts.
print("{0} v{1}: “{2}” is neither an Adobe Adept nor a Barnes & Noble encrypted ePub".format(PLUGIN_NAME, PLUGIN_VERSION, os.path.basename(path_to_ebook)))
- raise DeDRMError("{0} v{1}: Couldn't decrypt after {2:.1f} seconds. DRM free perhaps?".format(PLUGIN_NAME, PLUGIN_VERSION,time.time()-self.starttime))
+ return self.checkFonts(inf.name)
+ #raise DeDRMError("{0} v{1}: Couldn't decrypt after {2:.1f} seconds. DRM free perhaps?".format(PLUGIN_NAME, PLUGIN_VERSION,time.time()-self.starttime))
def PDFDecrypt(self,path_to_ebook):
import calibre_plugins.dedrm.prefs as prefs
# If we end up here, we didn't find a key with a matching UUID, so lets just try all of them.
-
+
# Attempt to decrypt epub with each encryption key (generated or provided).
for keyname, userkeyhex in dedrmprefs['adeptkeys'].items():
userkey = codecs.decode(userkeyhex,'hex')
import os, traceback, json, codecs
from PyQt5.Qt import (Qt, QWidget, QHBoxLayout, QVBoxLayout, QLabel, QLineEdit,
- QGroupBox, QPushButton, QListWidget, QListWidgetItem,
+ QGroupBox, QPushButton, QListWidget, QListWidgetItem, QCheckBox,
QAbstractItemView, QIcon, QDialog, QDialogButtonBox, QUrl,
QCheckBox)
self.tempdedrmprefs['serials'] = list(self.dedrmprefs['serials'])
self.tempdedrmprefs['adobewineprefix'] = self.dedrmprefs['adobewineprefix']
self.tempdedrmprefs['kindlewineprefix'] = self.dedrmprefs['kindlewineprefix']
+ self.tempdedrmprefs['deobfuscate_fonts'] = self.dedrmprefs['deobfuscate_fonts']
# Start Qt Gui dialog layout
layout = QVBoxLayout(self)
button_layout.addWidget(self.adept_button)
button_layout.addWidget(self.kindle_key_button)
+ self.chkFontObfuscation = QtGui.QCheckBox(_("Deobfuscate EPUB fonts"))
+ self.chkFontObfuscation.setToolTip("Deobfuscates fonts in EPUB files after DRM removal")
+ self.chkFontObfuscation.setChecked(self.tempdedrmprefs["deobfuscate_fonts"])
+ button_layout.addWidget(self.chkFontObfuscation)
+
self.resize(self.sizeHint())
def kindle_serials(self):
self.dedrmprefs.set('adobewineprefix', self.tempdedrmprefs['adobewineprefix'])
self.dedrmprefs.set('kindlewineprefix', self.tempdedrmprefs['kindlewineprefix'])
self.dedrmprefs.set('configured', True)
+ self.dedrmprefs.set('deobfuscate_fonts', self.chkFontObfuscation.isChecked())
self.dedrmprefs.writeprefs()
def load_resource(self, name):
--- /dev/null
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+
+# epubfontdecrypt.py
+# Copyright © 2021 by noDRM
+
+# Released under the terms of the GNU General Public Licence, version 3
+# <http://www.gnu.org/licenses/>
+
+
+# Revision history:
+# 1 - Initial release
+
+"""
+Decrypts / deobfuscates font files in EPUB files
+"""
+
+__license__ = 'GPL v3'
+__version__ = "1"
+
+import os
+import traceback
+import zlib
+import zipfile
+from zipfile import ZipInfo, ZipFile, ZIP_STORED, ZIP_DEFLATED
+from contextlib import closing
+import xml.etree.ElementTree as etree
+import itertools
+import hashlib
+import binascii
+
+
+class Decryptor(object):
+ def __init__(self, obfuscationkeyIETF, obfuscationkeyAdobe, encryption):
+ enc = lambda tag: '{%s}%s' % ('http://www.w3.org/2001/04/xmlenc#', tag)
+ dsig = lambda tag: '{%s}%s' % ('http://www.w3.org/2000/09/xmldsig#', tag)
+ self.obfuscation_key_Adobe = obfuscationkeyAdobe
+ self.obfuscation_key_IETF = obfuscationkeyIETF
+
+ self._encryption = etree.fromstring(encryption)
+ # This loops through all entries in the "encryption.xml" file
+ # to figure out which files need to be decrypted.
+ self._obfuscatedIETF = obfuscatedIETF = set()
+ self._obfuscatedAdobe = obfuscatedAdobe = set()
+ self._other = other = set()
+
+ self._json_elements_to_remove = json_elements_to_remove = set()
+ self._has_remaining_xml = False
+ expr = './%s/%s/%s' % (enc('EncryptedData'), enc('CipherData'),
+ enc('CipherReference'))
+ for elem in self._encryption.findall(expr):
+ path = elem.get('URI', None)
+ encryption_type_url = (elem.getparent().getparent().find("./%s" % (enc('EncryptionMethod'))).get('Algorithm', None))
+ if path is not None:
+
+ if encryption_type_url == "http://www.idpf.org/2008/embedding":
+ # Font files obfuscated with the IETF algorithm
+ path = path.encode('utf-8')
+ obfuscatedIETF.add(path)
+ if (self.obfuscation_key_IETF is None):
+ self._has_remaining_xml = True
+ else:
+ json_elements_to_remove.add(elem.getparent().getparent())
+
+ elif encryption_type_url == "http://ns.adobe.com/pdf/enc#RC":
+ # Font files obfuscated with the Adobe algorithm.
+ path = path.encode('utf-8')
+ obfuscatedAdobe.add(path)
+ if (self.obfuscation_key_Adobe is None):
+ self._has_remaining_xml = True
+ else:
+ json_elements_to_remove.add(elem.getparent().getparent())
+
+ else:
+ path = path.encode('utf-8')
+ other.add(path)
+ self._has_remaining_xml = True
+ # Other unsupported type.
+
+ for elem in json_elements_to_remove:
+ elem.getparent().remove(elem)
+
+ def check_if_remaining(self):
+ return self._has_remaining_xml
+
+ def get_xml(self):
+ return "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n" + etree.tostring(self._encryption, encoding="utf-8", pretty_print=True, xml_declaration=False).decode("utf-8")
+
+ def decompress(self, bytes):
+ dc = zlib.decompressobj(-15)
+ try:
+ decompressed_bytes = dc.decompress(bytes)
+ ex = dc.decompress(b'Z') + dc.flush()
+ if ex:
+ decompressed_bytes = decompressed_bytes + ex
+ except:
+ # possibly not compressed by zip - just return bytes
+ return bytes, False
+ return decompressed_bytes , True
+
+ def decrypt(self, path, data):
+ if path.encode('utf-8') in self._obfuscatedIETF and self.obfuscation_key_IETF is not None:
+ # de-obfuscate according to the IETF standard
+ data, was_decomp = self.decompress(data)
+
+ if len(data) <= 1040:
+ # de-obfuscate whole file
+ out = self.deobfuscate_single_data(self.obfuscation_key_IETF, data)
+ else:
+ out = self.deobfuscate_single_data(self.obfuscation_key_IETF, data[:1040]) + data[1040:]
+
+ if (not was_decomp):
+ out, was_decomp = self.decompress(out)
+ return out
+
+ elif path.encode('utf-8') in self._obfuscatedAdobe and self.obfuscation_key_Adobe is not None:
+ # de-obfuscate according to the Adobe standard
+ data, was_decomp = self.decompress(data)
+
+ if len(data) <= 1024:
+ # de-obfuscate whole file
+ out = self.deobfuscate_single_data(self.obfuscation_key_Adobe, data)
+ else:
+ out = self.deobfuscate_single_data(self.obfuscation_key_Adobe, data[:1024]) + data[1024:]
+
+ if (not was_decomp):
+ out, was_decomp = self.decompress(out)
+ return out
+
+ else:
+ # Not encrypted or obfuscated
+ return data
+
+ def deobfuscate_single_data(self, key, data):
+ msg = bytes([c^k for c,k in zip(data, itertools.cycle(key))])
+ return msg
+
+
+
+def decryptFontsBook(inpath, outpath):
+
+ with closing(ZipFile(open(inpath, 'rb'))) as inf:
+ namelist = set(inf.namelist())
+ if 'META-INF/encryption.xml' not in namelist:
+ print("{0:s} has no obfuscated fonts".format(os.path.basename(inpath)))
+ return 1
+
+ # Font key handling:
+
+ font_master_key = None
+ adobe_master_encryption_key = None
+
+ contNS = lambda tag: '{%s}%s' % ('urn:oasis:names:tc:opendocument:xmlns:container', tag)
+ path = None
+
+ try:
+ container = etree.fromstring(inf.read("META-INF/container.xml"))
+ rootfiles = container.find(contNS("rootfiles")).findall(contNS("rootfile"))
+ for rootfile in rootfiles:
+ path = rootfile.get("full-path", None)
+ if (path is not None):
+ break
+ except:
+ pass
+
+ # If path is None, we didn't find an OPF, so we probably don't have a font key.
+ # If path is set, it's the path to the main content OPF file.
+
+ if (path is None):
+ print("No OPF for font obfuscation found")
+ return 1
+ else:
+ packageNS = lambda tag: '{%s}%s' % ('http://www.idpf.org/2007/opf', tag)
+ metadataDCNS = lambda tag: '{%s}%s' % ('http://purl.org/dc/elements/1.1/', tag)
+
+ try:
+ container = etree.fromstring(inf.read(path))
+ except:
+ container = []
+
+ ## IETF font key algorithm:
+ print("Checking {0} for IETF font obfuscation keys ... ".format(path), end='')
+ secret_key_name = None
+ try:
+ secret_key_name = container.get("unique-identifier")
+ except:
+ pass
+
+ try:
+ identify_element = container.find(packageNS("metadata")).find(metadataDCNS("identifier"))
+ if (secret_key_name is None or secret_key_name == identify_element.get("id")):
+ font_master_key = identify_element.text
+ except:
+ pass
+
+ if (font_master_key is not None):
+ if (secret_key_name is None):
+ print("found '%s'" % (font_master_key))
+ else:
+ print("found '%s' (%s)" % (font_master_key, secret_key_name))
+
+ # Trim / remove forbidden characters from the key, then hash it:
+ font_master_key = font_master_key.replace(' ', '')
+ font_master_key = font_master_key.replace('\t', '')
+ font_master_key = font_master_key.replace('\r', '')
+ font_master_key = font_master_key.replace('\n', '')
+ font_master_key = font_master_key.encode('utf-8')
+ font_master_key = hashlib.sha1(font_master_key).digest()
+ else:
+ print("not found")
+
+ ## Adobe font key algorithm
+ print("Checking {0} for Adobe font obfuscation keys ... ".format(path), end='')
+
+ try:
+ metadata = container.find(packageNS("metadata"))
+ identifiers = metadata.findall(metadataDCNS("identifier"))
+
+ uid = None
+ uidMalformed = False
+
+ for identifier in identifiers:
+ if identifier.get(packageNS("scheme")) == "UUID":
+ if identifier.text[:9] == "urn:uuid:":
+ uid = identifier.text[9:]
+ else:
+ uid = identifier.text
+ break
+ if identifier.text[:9] == "urn:uuid:":
+ uid = identifier.text[9:]
+ break
+
+
+ if uid is not None:
+ uid = uid.replace(chr(0x20),'').replace(chr(0x09),'')
+ uid = uid.replace(chr(0x0D),'').replace(chr(0x0A),'').replace('-','')
+
+ if len(uid) < 16:
+ uidMalformed = True
+ if not all(c in "0123456789abcdefABCDEF" for c in uid):
+ uidMalformed = True
+
+
+ if not uidMalformed:
+ print("found '{0}'".format(uid))
+ uid = uid + uid
+ adobe_master_encryption_key = binascii.unhexlify(uid[:32])
+
+ if adobe_master_encryption_key is None:
+ print("not found")
+
+ except:
+ print("exception")
+ pass
+
+ # Begin decrypting.
+
+ try:
+ encryption = inf.read('META-INF/encryption.xml')
+ decryptor = Decryptor(font_master_key, adobe_master_encryption_key, encryption)
+ kwds = dict(compression=ZIP_DEFLATED, allowZip64=False)
+ with closing(ZipFile(open(outpath, 'wb'), 'w', **kwds)) as outf:
+
+ # Mimetype needs to be the first entry, so remove it from the list
+ # whereever it is, then add it at the beginning.
+ namelist.remove("mimetype")
+
+ for path in (["mimetype"] + namelist):
+ data = inf.read(path)
+ zi = ZipInfo(path)
+ zi.compress_type=ZIP_DEFLATED
+
+ if path == "mimetype":
+ # mimetype must not be compressed
+ zi.compress_type = ZIP_STORED
+
+ elif path == "META-INF/encryption.xml":
+ # Check if there's still other entries not related to fonts
+ if (decryptor.check_if_remaining()):
+ data = decryptor.get_xml()
+ print("There's remaining entries in encryption.xml, adding file ...")
+ else:
+ # No remaining entries, no need for that file.
+ continue
+
+ try:
+ # get the file info, including time-stamp
+ oldzi = inf.getinfo(path)
+ # copy across useful fields
+ zi.date_time = oldzi.date_time
+ zi.comment = oldzi.comment
+ zi.extra = oldzi.extra
+ zi.internal_attr = oldzi.internal_attr
+ # external attributes are dependent on the create system, so copy both.
+ zi.external_attr = oldzi.external_attr
+ zi.create_system = oldzi.create_system
+ 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
+
+ if path == "mimetype":
+ outf.writestr(zi, inf.read('mimetype'))
+ elif path == "META-INF/encryption.xml":
+ outf.writestr(zi, data)
+ else:
+ outf.writestr(zi, decryptor.decrypt(path, data))
+ except:
+ print("Could not decrypt fonts in {0:s} because of an exception:\n{1:s}".format(os.path.basename(inpath), traceback.format_exc()))
+ return 2
+ return 0
+
projects / DeDRM.git / commitdiff