code: public static PrivateKey generatePrivateKey(BigInteger modulus, BigInteger privateExponent) {
  		return SecureUtil.generatePrivateKey(ALGORITHM_RSA.getValue(), new RSAPrivateKeySpec(modulus, privateExponent));
  	}
docs: 生成RSA私钥
  
  @param modulus N特征值
  @param privateExponent d特征值
  @return {@link PrivateKey}