key := C._goboringcrypto_RSA_new()
	if key == nil {
		return nil, fail("RSA_new")
	}
	if !bigToBn(&key.n, N) ||
		!bigToBn(&key.e, E) ||
		!bigToBn(&key.d, D) ||
		!bigToBn(&key.p, P) ||
		!bigToBn(&key.q, Q) ||
		!bigToBn(&key.dmp1, Dp) ||
		!bigToBn(&key.dmq1, Dq) ||
		!bigToBn(&key.iqmp, Qinv) {
		return nil, fail("BN_bin2bn")
	}
	k := &PrivateKeyRSA{_key: key}

		panic("boringcrypto: bignum conversion failed")
	}
	return x
}

func bigToBn(bnp **C.GO_BIGNUM, b BigInt) bool {
	if *bnp != nil {
		C._goboringcrypto_BN_free(*bnp)
		*bnp = nil
	}
	if b == nil {
		return true
	}
	bn := bigToBN(b)
	if bn == nil {
		return false
	}
	*bnp = bn
	return true
}