parts          []ObjectPartInfo
	header         http.Header
	bucket, object string
	metadata       map[string]string

	partDecRelOffset, partEncRelOffset int64

	copySource bool
	// Customer Key
	customerKeyHeader string
}

func (d *DecryptBlocksReader) buildDecrypter(partID int) error {
	m := cloneMSS(d.metadata)
	// Initialize the first decrypter; new decrypters will be