raw := h.Sum(nil)
	c := Checksum{Type: t, Encoded: base64.StdEncoding.EncodeToString(raw), Raw: raw}
	if !c.Valid() {
		return nil
	}
	return &c
}

// ReadCheckSums will read checksums from b and return them.
func ReadCheckSums(b []byte, part int) map[string]string {
	res := make(map[string]string, 1)
	for len(b) > 0 {
		t, n := binary.Uvarint(b)
		if n < 0 {
			break
		}
		b = b[n:]

		decrypted, err := o.metadataDecrypter()("object-checksum", data)
		if err != nil {
			encLogIf(GlobalContext, err)
			return nil
		}
		data = decrypted
	}
	return hash.ReadCheckSums(data, part)