if err != nil {
		writeErrorResponse(ctx, w, errorCodes.ToAPIErr(ErrMalformedPOSTRequest), r.URL)
		return
	}

	hashReader, err := hash.NewReader(ctx, reader, fileSize, "", "", fileSize)
	if err != nil {
		writeErrorResponse(ctx, w, toAPIError(ctx, err), r.URL)
		return
	}
	if checksum != nil && checksum.Valid() {