C# 软件Licence应用实例

本文主要是介绍C# 软件Licence应用实例，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

我们在使用一些需要购买版权的软件产品时，或者我们做的商业软件需要进行售卖，为了收取费用，一般需要一个软件使用许可证，然后输入这个许可到软件里就能够使用软件。简单的是一串序列码或者一个许可证文件，复杂的是一个定制化插件包。于是有的小伙伴就开始好奇这个许可是怎么实现的，特别是在离线情况下它是怎么给软件授权，同时又能避免被破解的。

License应用场景

本文主要介绍的是许可证形式的授权。

1. 如何控制只在指定设备上使用

如果不控制指定设备，那么下发了许可证，只要把软件复制多份安装则可到处使用，不利于版权维护，每个设备都有唯一标识：mac地址，ip地址，主板序列号等，在许可证中指定唯一标识则只能指定设备使用。

2. 如何控制软件使用期限

为了版权可持续性收益，对软件使用设置期限，到期续费等，则需要在许可证中配置使用起止日期。

Licence实现方案

1. 流程设计

形式：许可证以文件形式下发，放在客户端电脑指定位置
内容：以上控制内容以dom节点形式放在文件中
流程：将控制项加密后写入license文件节点，部署到客户机器，客户机使用时再读取license文件内容与客户机实际参数进行匹配校验

2. 文件防破解

防止篡改：文件内容加密，使用AES加密，但是AES加密解密都是使用同一个key；使用非对称公私钥（本文使用的RSA）对内容加密解密，但是对内容长度有限制；综合方案，将AES的key（内部定义）用RSA加密，公钥放在加密工具中，内部持有，私钥放在解密工具中，引入软件产品解密使用。
防止修改系统时间绕过许可证使用时间：许可证带上发布时间戳，并定时修改运行时间记录到文件，如果系统时间小于这个时间戳，就算大于许可证限制的起始时间也无法使用
提高破解难度：懂技术的可以将代码反编译过来修改代码文件直接绕过校验，所以需要进行代码混淆，有测试过xjar的混淆效果比较好。

Licence验证流程图

关于Licence验证软件合法性流程图，如下所示：

核心源码

本实例主要讲解Licence的实际验证过程，分为三部分：

测试客户端【LicenceTest】，主要用于模拟客户端验证Licence的过程。
生成工具【LicenceTool】，主要用于根据客户生成的电脑文件，生成对应的Licence。
LicenceCommon，Licence公共通用类，主要实现电脑信息获取，非对称加密，文件保存等功能。

1. LicenceCommon

1.1 电脑信息获取

主要通过ManagementClass进行获取客户端电脑硬件相关配置信息，如下所示：

using Microsoft.Win32;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Management;
using System.Net.NetworkInformation;
using System.Text;
using System.Threading.Tasks;namespace DemoLicence.Common
{public class ComputerHelper{public static Dictionary<string,string> GetComputerInfo(){var info = new Dictionary<string,string>();string cpu = GetCPUInfo();string baseBoard = GetBaseBoardInfo();string bios = GetBIOSInfo();string mac = GetMACInfo();info.Add("cpu", cpu);info.Add("baseBoard", baseBoard);info.Add("bios", bios);info.Add("mac", mac);return info;}private static string GetCPUInfo(){string info = string.Empty;info = GetHardWareInfo("Win32_Processor", "ProcessorId");return info;}private static string GetBIOSInfo(){string info = string.Empty;info = GetHardWareInfo("Win32_BIOS", "SerialNumber");return info;}private static string GetBaseBoardInfo(){string info = string.Empty;info = GetHardWareInfo("Win32_BaseBoard", "SerialNumber");return info;}private static string GetMACInfo(){string info = string.Empty;info = GetMacAddress();//GetHardWareInfo("Win32_NetworkAdapterConfiguration", "MACAddress");return info;}private static string GetMacAddress(){var mac = "";var mc = new ManagementClass("Win32_NetworkAdapterConfiguration");var moc = mc.GetInstances();foreach (var o in moc){var mo = (ManagementObject)o;if (!(bool)mo["IPEnabled"]) continue;mac = mo["MacAddress"].ToString();break;}return mac;}private static string GetHardWareInfo(string typePath, string key){try{ManagementClass managementClass = new ManagementClass(typePath);ManagementObjectCollection mn = managementClass.GetInstances();PropertyDataCollection properties = managementClass.Properties;foreach (PropertyData property in properties){if (property.Name == key){foreach (ManagementObject m in mn){return m.Properties[property.Name].Value.ToString();}}}}catch (Exception ex){//这里写异常的处理}return string.Empty;}}
}

1.2 RSA非对称加密

主要对客户端提供的电脑信息及有效期等内容，进行非对称加密，如下所示：

public class RSAHelper
{private static string keyContainerName = "star";private static string m_PriKey = string.Empty;private static string m_PubKey = string.Empty;public static string PriKey{get{return m_PriKey;}set{m_PriKey = value;}}public static string PubKey{get{return m_PubKey;}set{m_PubKey = value;}}public static string Encrypto(string source){if (string.IsNullOrEmpty(m_PubKey) && string.IsNullOrEmpty(m_PriKey)){generateKey();}return getEncryptoInfoByRSA(source);}public static string Decrypto(string dest){if (string.IsNullOrEmpty(m_PubKey) && string.IsNullOrEmpty(m_PriKey)){generateKey();}return getDecryptoInfoByRSA(dest);}public static void generateKey(){CspParameters m_CspParameters;m_CspParameters = new CspParameters();m_CspParameters.KeyContainerName = keyContainerName;RSACryptoServiceProvider asym = new RSACryptoServiceProvider(m_CspParameters);m_PriKey = asym.ToXmlString(true);m_PubKey = asym.ToXmlString(false);asym.PersistKeyInCsp = false;asym.Clear();}private static string getEncryptoInfoByRSA(string source){byte[] plainByte = Encoding.ASCII.GetBytes(source);//初始化参数RSACryptoServiceProvider asym = new RSACryptoServiceProvider();asym.FromXmlString(m_PubKey);int keySize = asym.KeySize / 8;//非对称加密，每次的长度不能太长，否则会报异常int bufferSize = keySize - 11;if (plainByte.Length > bufferSize){throw new Exception("非对称加密最多支持【" + bufferSize + "】字节，实际长度【" + plainByte.Length + "】字节。");}byte[] cryptoByte = asym.Encrypt(plainByte, false);return Convert.ToBase64String(cryptoByte);}private static string getDecryptoInfoByRSA(string dest){byte[] btDest = Convert.FromBase64String(dest);//初始化参数RSACryptoServiceProvider asym = new RSACryptoServiceProvider();asym.FromXmlString(m_PriKey);int keySize = asym.KeySize / 8;//非对称加密，每次的长度不能太长，否则会报异常//int bufferSize = keySize - 11;if (btDest.Length > keySize){throw new Exception("非对称解密最多支持【" + keySize + "】字节，实际长度【" + btDest.Length + "】字节。");}byte[] cryptoByte = asym.Decrypt(btDest, false);return Encoding.ASCII.GetString(cryptoByte);}
}

1.3 生成文件

主要是加密后的信息，和解密秘钥等内容，保存到文件中，如下所示：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;namespace DemoLicence.Common
{public class RegistFileHelper{public static string ComputerInfofile = "ComputerInfo.key";public static string RegistInfofile = "Licence.key";public static void WriteRegistFile(string info,string keyFile){string tmp = string.IsNullOrEmpty(keyFile)?RegistInfofile:keyFile;WriteFile(info, tmp);}public static void WriteComputerInfoFile(string info){WriteFile(info, ComputerInfofile);}public static string ReadRegistFile(string keyFile){string tmp = string.IsNullOrEmpty(keyFile) ? RegistInfofile : keyFile;return ReadFile(tmp);}public static string ReadComputerInfoFile(string file){string tmp = string.IsNullOrEmpty(file) ? ComputerInfofile : file;return ReadFile(tmp);}private static void WriteFile(string info, string fileName){try{using (StreamWriter sw = new StreamWriter(fileName, false)){sw.Write(info);sw.Close();}}catch (Exception ex){}}private static string ReadFile(string fileName){string info = string.Empty;try{using (StreamReader sr = new StreamReader(fileName)){info = sr.ReadToEnd();sr.Close();}}catch (Exception ex){}return info;}}
}

以上这三部分，各个功能相互独立，通过LicenceHelper相互调用，如下所示：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.CompilerServices;
using System.Text;
using System.Threading.Tasks;namespace DemoLicence.Common
{public class LicenceHelper{/// <summary>/// 获取电脑信息，并生成文件/// </summary>public static string GetComputerInfoAndGenerateFile(){string computerKeyFile = string.Empty;try{var info = GetComputerInfo();if (info != null && info.Count > 0){//获取到电脑信息var strInfo = new StringBuilder();foreach (var computer in info){strInfo.AppendLine($"{computer.Key}={computer.Value}");}RegistFileHelper.WriteComputerInfoFile(strInfo.ToString());computerKeyFile = RegistFileHelper.ComputerInfofile;}}catch(Exception ex){throw ex;}return computerKeyFile;}public static Dictionary<string,string> GetComputerInfo(){var info = ComputerHelper.GetComputerInfo();return info;}public static bool CheckLicenceKeyIsExists(){var keyFile = RegistFileHelper.RegistInfofile;if (File.Exists(keyFile)){return true;}else{return false;}}public static string GetComputerInfo(string computerInfoFile){return RegistFileHelper.ReadComputerInfoFile(computerInfoFile);}public static void GenerateLicenceKey(string info,string keyfile){string encrypto = RSAHelper.Encrypto(info);string priKey = RSAHelper.PriKey;//公钥加密，私钥解密byte[] priKeyBytes = Encoding.ASCII.GetBytes(priKey);string priKeyBase64=Convert.ToBase64String(priKeyBytes);StringBuilder keyInfo= new StringBuilder();keyInfo.AppendLine($"prikey={priKeyBase64}");keyInfo.AppendLine($"encrypto={encrypto}");RegistFileHelper.WriteRegistFile(keyInfo.ToString(), keyfile);}public static string ReadLicenceKey(string keyfile){var keyInfo = RegistFileHelper.ReadRegistFile(keyfile);if (keyInfo == null){return string.Empty;}string[] keyInfoArr = keyInfo.Split("\r\n");var priKeyBase64 = keyInfoArr[0].Substring(keyInfoArr[0].IndexOf("=")+1);var encrypto = keyInfoArr[1].Substring(keyInfoArr[1].IndexOf("=")+1);var priKeyByte= Convert.FromBase64String(priKeyBase64);var priKey = Encoding.ASCII.GetString(priKeyByte);RSAHelper.PriKey= priKey;var info = RSAHelper.Decrypto(encrypto);return info;}public static string GetDefaultRegisterFileName(){return RegistFileHelper.RegistInfofile;}public static string GetDefaultComputerFileName(){return RegistFileHelper.ComputerInfofile;}public static string GetPublicKey(){if (string.IsNullOrEmpty(RSAHelper.PubKey)){RSAHelper.generateKey();}return RSAHelper.PubKey;}public static string GetPrivateKey(){if (string.IsNullOrEmpty(RSAHelper.PriKey)){RSAHelper.generateKey();}return RSAHelper.PriKey;}}
}

2. 客户端LicenceTest

客户端验证Licence的有效性，当Licence有效时，正常使用软件，当Licence无效时，则不能正常使用软件。如下所示：

using DemoLicence.Common;namespace LicenceTest
{public partial class MainForm : Form{public MainForm(){InitializeComponent();}private void MainForm_Load(object sender, EventArgs e){try{string info = string.Empty;string msg = string.Empty;//初始化加载if (LicenceHelper.CheckLicenceKeyIsExists()){string keyFile = LicenceHelper.GetDefaultRegisterFileName();info = LicenceHelper.ReadLicenceKey(keyFile);}else{var dialogResult = MessageBox.Show("没有找到默认首选文件，是否手动选择授权文件？", "询问", MessageBoxButtons.YesNo);if (dialogResult == DialogResult.Yes){OpenFileDialog openFileDialog = new OpenFileDialog();openFileDialog.Title = "请选择授权文件";openFileDialog.FileName = LicenceHelper.GetDefaultRegisterFileName();if (openFileDialog.ShowDialog() == DialogResult.OK){var keyFile = openFileDialog.FileName;info = LicenceHelper.ReadLicenceKey(keyFile);//验证成功后，将手动选择的文件复制到程序根目录,且修改为默认名称File.Copy(keyFile, LicenceHelper.GetDefaultRegisterFileName());}else{string computerFile = LicenceHelper.GetComputerInfoAndGenerateFile();if (!string.IsNullOrEmpty(computerFile)){msg = $"您还没有被授权，请将程序根目录下的{computerFile}文件，发送到管理员，获取Licence.";}}}else{string computerFile = LicenceHelper.GetComputerInfoAndGenerateFile();if (!string.IsNullOrEmpty(computerFile)){msg = $"您还没有被授权，请将程序根目录下的{computerFile}文件，发送到管理员，获取Licence.";}}}if (!string.IsNullOrEmpty(info) && string.IsNullOrEmpty(msg)){string[] infos = info.Split("\r\n");if (infos.Length > 0){var dicInfo = new Dictionary<string, string>();foreach (var info2 in infos){if (string.IsNullOrEmpty(info2)){continue;}var info2Arr = info2.Split("=");dicInfo.Add(info2Arr[0], info2Arr[1]);}if (dicInfo.Count > 0){string localMacAddress = string.Empty;var computerInfo = LicenceHelper.GetComputerInfo();if (computerInfo != null){localMacAddress = computerInfo["mac"];}//比较本地信息和Licence中的信息是否一致if (localMacAddress == dicInfo["mac"]){var endTime = DateTime.Parse(dicInfo["endTime"]);if (DateTime.Now < endTime){//在有效期内，可以使用}else{msg = $"软件授权使用时间范围：[{endTime}之前]，已过期";}}else{msg = "软件Licence不匹配";}}else{msg = $"软件Licence非法.";}}else{msg = $"软件Licence非法.";}}if (!string.IsNullOrEmpty(msg)){MessageBox.Show(msg);foreach (var control in this.Controls){(control as Control).Enabled = false;}return;}}catch (Exception ex){string error = $"程序异常，请联系管理人员：{ex.Message}\r\n{ex.StackTrace}";MessageBox.Show(error);foreach (var control in this.Controls){(control as Control).Enabled = false;}}}}
}

3. Licence生成工具

LicenceTool主要根据客户端提供的电脑信息，生成对应的Licence，然后再发送给客户端，以此达到客户端电脑的授权使用软件的目的。如下所示：

using DemoLicence.Common;
using System.Text;namespace LicenceTool
{public partial class MainForm : Form{public MainForm(){InitializeComponent();}private void MainForm_Load(object sender, EventArgs e){this.txtPublicKey.Text=LicenceHelper.GetPublicKey();this.txtPrivateKey.Text=LicenceHelper.GetPrivateKey();}private void btnBrowser_Click(object sender, EventArgs e){OpenFileDialog ofd = new OpenFileDialog();ofd.Filter = "电脑信息文件|*.key";ofd.Multiselect = false;ofd.Title = "请选择电脑信息文件";ofd.FileName=LicenceHelper.GetDefaultComputerFileName();if (ofd.ShowDialog() == DialogResult.OK){this.txtSourceFile.Text = ofd.FileName;}}private void btnGenerate_Click(object sender, EventArgs e){try{if (string.IsNullOrEmpty(this.txtSourceFile.Text)){MessageBox.Show("请先选择电脑信息文件");return;}if (File.Exists(this.txtSourceFile.Text)){//读取电脑文件var info = LicenceHelper.GetComputerInfo(this.txtSourceFile.Text);int days = GetLicenceDays();var keyInfos = new StringBuilder(info);var beginTime = DateTime.Now;var endTime = DateTime.Now.AddDays(days);//keyInfos.AppendLine($"beginTime={beginTime.ToString("yyyy-MM-dd HH:mm:ss")}");keyInfos.AppendLine($"endTime={endTime.ToString("yyyy-MM-dd HH:mm:ss")}");//info = keyInfos.ToString();SaveFileDialog saveFileDialog = new SaveFileDialog();saveFileDialog.Title = "保存生成的Licence文件";saveFileDialog.FileName = LicenceHelper.GetDefaultRegisterFileName();if (saveFileDialog.ShowDialog() == DialogResult.OK){LicenceHelper.GenerateLicenceKey(info, saveFileDialog.FileName);MessageBox.Show("生成成功");}}else{MessageBox.Show("电脑信息文件不存在！");return;}}catch(Exception ex){string error = $"生成出错：{ex.Message}\r\n{ex.StackTrace}";MessageBox.Show(error);}}/// <summary>/// 获取有效期天数/// </summary>/// <returns></returns>private int GetLicenceDays(){int days = 1;RadioButton[] rbtns = new RadioButton[] { this.rbtSeven, this.rbtnTen, this.rbtnFifteen, this.rbtnThirty, this.rbtnSixty, this.rbtnSixMonth, this.rbtnNinety, this.rbtnSixMonth, this.rbtnForver };foreach (RadioButton rb in rbtns){if (rb.Checked){if (!int.TryParse(rb.Tag.ToString(), out days)){days = 0;}break;}}days = days == -1 ? 9999 : days;//永久要转换一下return days;}}
}