var err error
	var n1 int
	decPartSize, _ := sio.DecryptedSize(uint64(d.parts[d.partIndex].Size))
	unreadPartLen := int64(decPartSize) - d.partDecRelOffset
	if int64(len(p)) < unreadPartLen {
		n1, err = d.decrypter.Read(p)
		if err != nil {
			return 0, err
		}
		d.partDecRelOffset += int64(n1)
	} else {
		n1, err = io.ReadFull(d.decrypter, p[:unreadPartLen])
		if err != nil {