kind, _ := crypto.IsEncrypted(fi.Metadata)

	var objectEncryptionKey []byte
	switch kind {
	case crypto.SSEC:
		if checksumType.IsSet() {
			if opts.EncryptFn == nil {
				return oi, crypto.ErrMissingCustomerKey
			}
			baseKey := opts.EncryptFn("", nil)
			if len(baseKey) != 32 {
				return oi, crypto.ErrInvalidCustomerKey
			}

			if opts.EncryptFn != nil {
				fi.Checksum = opts.EncryptFn("object-checksum", fi.Checksum)
			}
		}
	} else if fi.Checksum == nil && opts.WantChecksum != nil {
		// Trailing headers checksums should now be filled.
		fi.Checksum = opts.WantChecksum.AppendTo(nil, nil)
		if opts.EncryptFn != nil {
			fi.Checksum = opts.EncryptFn("object-checksum", fi.Checksum)
		}
	}