//
// DecryptObjectInfo also returns whether the object is encrypted or not.
func DecryptObjectInfo(info *ObjectInfo, r *http.Request) (encrypted bool, err error) {
	// Directories are never encrypted.
	if info.IsDir {
		return false, nil
	}
	if r == nil {
		return false, errInvalidArgument
	}

	headers := r.Header

	// disallow X-Amz-Server-Side-Encryption header on HEAD and GET
	switch r.Method {