Generate Zip64 archive with data in zip64 end-of-archive record

generate-archive.py

import struct
import zipfile
from zipfile import *

structCentralDir = "<4s4B4HL2L5H2L"
stringCentralDir = b"PK\001\002"
sizeCentralDir = struct.calcsize(structCentralDir)

structEndArchive = b"<4s4H2LH"
stringEndArchive = b"PK\005\006"
sizeEndCentDir = struct.calcsize(structEndArchive)

structEndArchive64Locator = "<4sLQL"
stringEndArchive64Locator = b"PK\x06\x07"
sizeEndCentDir64Locator = struct.calcsize(structEndArchive64Locator)

structEndArchive64 = "<4sQ2H2L4Q"
stringEndArchive64 = b"PK\x06\x06"
sizeEndCentDir64 = struct.calcsize(structEndArchive64)


class SpecialZipFile(zipfile.ZipFile):
    def _write_end_record(self):
        # Write central directory
        for zinfo in self.filelist:
            dt = zinfo.date_time
            dosdate = (dt[0] - 1980) << 9 | dt[1] << 5 | dt[2]
            dostime = dt[3] << 11 | dt[4] << 5 | (dt[5] // 2)
            file_size = zinfo.file_size
            compress_size = zinfo.compress_size
            header_offset = zinfo.header_offset
            extra_data = zinfo.extra
            min_version = 0

            extract_version = max(min_version, zinfo.extract_version)
            create_version = max(min_version, zinfo.create_version)
            filename, flag_bits = zinfo._encodeFilenameFlags()
            centdir = struct.pack(structCentralDir,
                                  stringCentralDir, create_version,
                                  zinfo.create_system, extract_version, zinfo.reserved,
                                  flag_bits, zinfo.compress_type, dostime, dosdate,
                                  zinfo.CRC, compress_size, file_size,
                                  len(filename), len(extra_data), len(zinfo.comment),
                                  0, zinfo.internal_attr, zinfo.external_attr,
                                  header_offset)
            self.fp.write(centdir)
            self.fp.write(filename)
            self.fp.write(extra_data)
            self.fp.write(zinfo.comment)

        pos2 = self.fp.tell()

        # Write end-of-zip-archive record
        centDirCount = len(self.filelist)
        centDirSize = pos2 - self.start_dir
        centDirOffset = self.start_dir

        # Write the ZIP64 end-of-archive records
        if not self._allowZip64:
            raise LargeZipFile("Require ZIP64 extensions")

        additionalData = b"additional data at the end of ZIP64 EOCD record"

        zip64endrec = struct.pack(
            structEndArchive64, stringEndArchive64,
            44 + len(additionalData), 45, 45, 0, 0, centDirCount, centDirCount,
            centDirSize, centDirOffset)
        self.fp.write(zip64endrec)
        self.fp.write(additionalData)

        zip64locrec = struct.pack(
            structEndArchive64Locator,
            stringEndArchive64Locator, 0, pos2, 1)
        self.fp.write(zip64locrec)
        centDirCount = min(centDirCount, 0xFFFF)
        centDirSize = min(centDirSize, 0xFFFFFFFF)
        centDirOffset = min(centDirOffset, 0xFFFFFFFF)

        endrec = struct.pack(structEndArchive, stringEndArchive,
                             0, 0, centDirCount, centDirCount,
                             centDirSize, centDirOffset, 0)
        self.fp.write(endrec)
        if self.mode == "a":
            self.fp.truncate()
        self.fp.flush()


def run():
    with SpecialZipFile("archive.zip", mode="w",
                        compression=ZIP_DEFLATED, compresslevel=0,
                        allowZip64=True) as zf:
        with zf.open("file.txt", mode="w", force_zip64=True) as zi:
            zi.write(b"content")


if __name__ == '__main__':
    run()