}

func bigBytesECDH(curve string, big *C.GO_BIGNUM) ([]byte, error) {
	out := make([]byte, curveSize(curve))
	if C._goboringcrypto_BN_bn2bin_padded((*C.uint8_t)(&out[0]), C.size_t(len(out)), big) == 0 {
		return nil, fail("BN_bn2bin_padded")
	}
	return out, nil
}

func curveSize(curve string) int {
	switch curve {
	default:
		panic("crypto/internal/boring: unknown curve " + curve)