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

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

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

190 lines
6.2 KiB
Python

#!/usr/bin/env python
# -*- coding: utf-8 -*-
# zipfix.py
# Copyright © 2010-2020 by some_updates, DiapDealer and Apprentice Alf
# Released under the terms of the GNU General Public Licence, version 3
# <http://www.gnu.org/licenses/>
# Revision history:
# 1.0 - Initial release
# 1.1 - Updated to handle zip file metadata correctly
# 2.0 - Added Python 3 compatibility for calibre 5.0
"""
Re-write zip (or ePub) fixing problems with file names (and mimetype entry).
"""
from __future__ import print_function
__license__ = 'GPL v3'
__version__ = "1.1"
import sys
import zlib
import calibre_plugins.dedrm.zipfilerugged as zipfilerugged
import os
import os.path
import getopt
from struct import unpack
_FILENAME_LEN_OFFSET = 26
_EXTRA_LEN_OFFSET = 28
_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):
self.ztype = 'zip'
if zinput.lower().find('.epub') >= 0 :
self.ztype = 'epub'
self.inzip = zipfilerugged.ZipFile(zinput,'r')
self.outzip = zipfilerugged.ZipFile(zoutput,'w')
# open the input zip for reading only as a raw file
self.bzf = open(zinput,'rb')
def getlocalname(self, zi):
local_header_offset = zi.header_offset
self.bzf.seek(local_header_offset + _FILENAME_LEN_OFFSET)
leninfo = self.bzf.read(2)
local_name_length, = unpack('<H', leninfo)
self.bzf.seek(local_header_offset + _FILENAME_OFFSET)
local_name = self.bzf.read(local_name_length)
return local_name
def uncompress(self, cmpdata):
dc = zlib.decompressobj(-15)
data = ''
while len(cmpdata) > 0:
if len(cmpdata) > _MAX_SIZE :
newdata = cmpdata[0:_MAX_SIZE]
cmpdata = cmpdata[_MAX_SIZE:]
else:
newdata = cmpdata
cmpdata = ''
newdata = dc.decompress(newdata)
unprocessed = dc.unconsumed_tail
if len(unprocessed) == 0:
newdata += dc.flush()
data += newdata
cmpdata += unprocessed
unprocessed = ''
return data
def getfiledata(self, zi):
# get file name length and exta data length to find start of file data
local_header_offset = zi.header_offset
self.bzf.seek(local_header_offset + _FILENAME_LEN_OFFSET)
leninfo = self.bzf.read(2)
local_name_length, = unpack('<H', leninfo)
self.bzf.seek(local_header_offset + _EXTRA_LEN_OFFSET)
exinfo = self.bzf.read(2)
extra_field_length, = unpack('<H', exinfo)
self.bzf.seek(local_header_offset + _FILENAME_OFFSET + local_name_length + extra_field_length)
data = None
# if not compressed we are good to go
if zi.compress_type == zipfilerugged.ZIP_STORED:
data = self.bzf.read(zi.file_size)
# if compressed we must decompress it using zlib
if zi.compress_type == zipfilerugged.ZIP_DEFLATED:
cmpdata = self.bzf.read(zi.compress_size)
data = self.uncompress(cmpdata)
return data
def fix(self):
# get the zipinfo for each member of the input archive
# and copy member over to output archive
# if problems exist with local vs central filename, fix them
# 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.internal_attr = 1 # text file
try:
# if the mimetype is present, get its info, including time-stamp
oldmimeinfo = self.inzip.getinfo('mimetype')
# copy across useful fields
mimeinfo.date_time = oldmimeinfo.date_time
mimeinfo.comment = oldmimeinfo.comment
mimeinfo.extra = oldmimeinfo.extra
mimeinfo.internal_attr = oldmimeinfo.internal_attr
mimeinfo.external_attr = oldmimeinfo.external_attr
mimeinfo.create_system = oldmimeinfo.create_system
except:
pass
self.outzip.writestr(mimeinfo, _MIMETYPE.encode('ascii'))
# write the rest of the files
for zinfo in self.inzip.infolist():
if zinfo.filename != "mimetype" or self.ztype != 'epub':
data = None
try:
data = self.inzip.read(zinfo.filename)
except zipfilerugged.BadZipfile or zipfilerugged.error:
local_name = self.getlocalname(zinfo)
data = self.getfiledata(zinfo)
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.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
self.outzip.writestr(nzinfo,data)
self.bzf.close()
self.inzip.close()
self.outzip.close()
def usage():
print("""usage: zipfix.py inputzip outputzip
inputzip is the source zipfile to fix
outputzip is the fixed zip archive
""")
def repairBook(infile, outfile):
if not os.path.exists(infile):
print("Error: Input Zip File does not exist")
return 1
try:
fr = fixZip(infile, outfile)
fr.fix()
return 0
except Exception as e:
print("Error Occurred ", e)
return 2
def main(argv=sys.argv):
if len(argv)!=3:
usage()
return 1
infile = argv[1]
outfile = argv[2]
return repairBook(infile, outfile)
if __name__ == '__main__' :
sys.exit(main())