return nil, 0, 0, err
		}
		var decryptSkip int64
		var seqNum uint32

		off, length = int64(0), oi.Size
		decOff, decLength := int64(0), actualSize
		if rs != nil {
			off, length, err = rs.GetOffsetLength(actualSize)
			if err != nil {
				return nil, 0, 0, err
			}
			decrypt := func(b []byte) ([]byte, error) {
				return b, nil
			}
			if isEncrypted {
				decrypt = func(b []byte) ([]byte, error) {

		writeCopyPartErr(ctx, w, partRangeErr, r.URL)
		return
	}

	// Get the object offset & length
	startOffset, length, err := rs.GetOffsetLength(actualPartSize)
	if err != nil {
		writeErrorResponse(ctx, w, toAPIError(ctx, err), r.URL)
		return
	}

	// maximum copy size for multipart objects in a single operation
	if isMaxObjectSize(length) {

		if err != nil {
			err = errObjectTampered
			return
		}
		sizes = []int64{int64(partSize)}
		decObjSize = sizes[0]
	}

	var off, length int64
	off, length, err = rs.GetOffsetLength(decObjSize)
	if err != nil {
		return
	}

	// At this point, we have:
	//
	// 1. the decrypted part sizes in `sizes` (single element for