err := hash.ChecksumMismatch{
					Want: opts.WantChecksum.Encoded,
					Got:  checksum.Encoded,
				}
				return oi, err
			}
		} else {
			err := opts.WantChecksum.Matches(checksumCombined, len(parts))
			if err != nil {
				return oi, err
			}
		}
	}

	// Accept encrypted checksum from incoming request.
	if opts.UserDefined[ReplicationSsecChecksumHeader] != "" {