cdata.py

#!/usr/bin/python3
import struct
import sys
import zipfile

zfile, entry = sys.argv[1:]

with zipfile.ZipFile(zfile) as zf:
    info = zf.getinfo(entry)
    with open(zfile, "rb") as fh:
        fh.seek(info.header_offset)
        n, m = struct.unpack("<HH", fh.read(30)[26:30])
        fh.seek(info.header_offset + 30 + n + m)
        cdata, size = b"", info.compress_size
        while size > 0:
            cdata += fh.read(min(size, 4096))
            size -= 4096

sys.stdout.buffer.write(cdata)

clevel.py

#!/usr/bin/python3
import struct
import sys
import zipfile
import zlib

zfile, entry = sys.argv[1:]

with zipfile.ZipFile(zfile) as zf:
    data = zf.read(entry)
    info = zf.getinfo(entry)
    with open(zfile, "rb") as fh:
        fh.seek(info.header_offset)
        n, m = struct.unpack("<HH", fh.read(30)[26:30])
        fh.seek(info.header_offset + 30 + n + m)
        cdata, size = b"", info.compress_size
        while size > 0:
            cdata += fh.read(min(size, 4096))
            size -= 4096

levels = list(range(0, 9 + 1))
wbitss = list(range(-15, -9 + 1))
memLevels = list(range(1, 9 + 1))
strategies = list(range(0, 4 + 1))

for level in levels:
    for wbits in wbitss:
        for memLevel in memLevels:
            for strategy in strategies:
                co = zlib.compressobj(level=level, wbits=wbits, memLevel=memLevel, strategy=strategy)
                cd = co.compress(data) + co.flush()
                if cd == cdata:
                    print(dict(level=level, wbits=wbits, memLevel=memLevel, strategy=strategy))