(转)C#创建数字证书并导出为pfx，并使用pfx进行非对称加解密

我的项目当中，考虑到安全性，需要为每个客户端分发一个数字证书，同时使用数字证书中的公私钥来进行数据的加解密。为了完成这个安全模块，特写了如下一个DEMO程序，该DEMO程序包含的功能有：

1：调用.NET2.0的MAKECERT创建含有私钥的数字证书，并存储到个人证书区；

2：将该证书导出为pfx文件，并为其指定一个用来打开pfx文件的password；

3：读取pfx文件，导出pfx中公钥和私钥；

4：用pfx证书中的公钥进行数据的加密，用私钥进行数据的解密；

代码如下：

code 

/// <summary>   
        /// 将证书从证书存储区导出，并存储为pfx文件，同时为pfx文件指定打开的密码   
        /// 本函数同时也演示如何用公钥进行加密，私钥进行解密   
        /// </summary>   
        /// <param name="sender"></param>   
        /// <param name="e"></param>   
        private void btn_toPfxFile_Click(object sender, EventArgs e)   
        {   
            X509Store store = new X509Store(StoreName.My, StoreLocation.CurrentUser);   
            store.Open(OpenFlags.ReadWrite);   
            X509Certificate2Collection storecollection = (X509Certificate2Collection)store.Certificates;   
            foreach (X509Certificate2 x509 in storecollection)   
            {   
                if (x509.Subject == "CN=luminji")   
                {   
                    Debug.Print(string.Format("certificate name: {0}", x509.Subject));   
                    byte[] pfxByte = x509.Export(X509ContentType.Pfx, "123");   
                    using (FileStream  fileStream = new FileStream("luminji.pfx", FileMode.Create))   
                    {   
                        // Write the data to the file, byte by byte.   
                        for (int i = 0; i < pfxByte.Length; i++)   
                            fileStream.WriteByte(pfxByte[i]);   
                        // Set the stream position to the beginning of the file.   
                        fileStream.Seek(0, SeekOrigin.Begin);   
                        // Read and verify the data.   
                        for (int i = 0; i < fileStream.Length; i++)   
                        {   
                            if (pfxByte[i] != fileStream.ReadByte())   
                            {   
                                Debug.Print("Error writing data.");   
                                return;   
                            }   
                        }   
                        fileStream.Close();   
                        Debug.Print("The data was written to {0} " +   
                            "and verified.", fileStream.Name);   
                    }   
                    string myname = "my name is luminji! and i love huzhonghua!";   
                    string enStr = this.RSAEncrypt(x509.PublicKey.Key.ToXmlString(false), myname);   
                    MessageBox.Show("密文是：" + enStr);   
                    string deStr = this.RSADecrypt(x509.PrivateKey.ToXmlString(true), enStr);   
                    MessageBox.Show("明文是：" + deStr);   
                }   
            }   
            store.Close();   
            store = null;   
            storecollection = null;   
        }   
        /// <summary>   
        /// 创建还有私钥的证书   
        /// </summary>   
        /// <param name="sender"></param>   
        /// <param name="e"></param>   
        private void btn_createPfx_Click(object sender, EventArgs e)   
        {   
            string MakeCert = "C:\\Program Files\\Microsoft Visual Studio 8\\SDK\\v2.0\\Bin\\makecert.exe";   
            string x509Name = "CN=luminji";   
            string param = " -pe -ss my -n \"" + x509Name + "\" " ;   
            Process p = Process.Start(MakeCert, param);   
            p.WaitForExit();   
            p.Close();   
            MessageBox.Show("over");   
        }   
        /// <summary>   
        /// 从pfx文件读取证书信息   
        /// </summary>   
        /// <param name="sender"></param>   
        /// <param name="e"></param>   
        private void btn_readFromPfxFile(object sender, EventArgs e)   
        {   
            X509Certificate2 pc = new X509Certificate2("luminji.pfx", "123");   
            MessageBox.Show("name:" + pc.SubjectName.Name);   
            MessageBox.Show("public:" + pc.PublicKey.ToString());   
            MessageBox.Show("private:" + pc.PrivateKey.ToString());   
            pc = null;   
        }   
        /// <summary>   
        /// RSA解密   
        /// </summary>   
        /// <param name="xmlPrivateKey"></param>   
        /// <param name="m_strDecryptString"></param>   
        /// <returns></returns>   
        public string RSADecrypt(string xmlPrivateKey, string m_strDecryptString)   
        {   
            RSACryptoServiceProvider provider = new RSACryptoServiceProvider();   
            provider.FromXmlString(xmlPrivateKey);   
            byte[] rgb = Convert.FromBase64String(m_strDecryptString);   
            byte[] bytes = provider.Decrypt(rgb, false);   
            return new UnicodeEncoding().GetString(bytes);   
        }   
        /// <summary>   
        /// RSA加密   
        /// </summary>   
        /// <param name="xmlPublicKey"></param>   
        /// <param name="m_strEncryptString"></param>   
        /// <returns></returns>   
        public string RSAEncrypt(string xmlPublicKey, string m_strEncryptString)   
        {   
            RSACryptoServiceProvider provider = new RSACryptoServiceProvider();   
            provider.FromXmlString(xmlPublicKey);   
            byte[] bytes = new UnicodeEncoding().GetBytes(m_strEncryptString);   
            return Convert.ToBase64String(provider.Encrypt(bytes, false));   
        }  

上文是一个示例程序，一个完整的证书工具类如下：

 

code 

  1 ·········10········20········30········40········50········60········70········80········90········100·······110·······120·······130·······140·······150
  2 public sealed class DataCertificate  
  3     {  
  4         #region 生成证书  
  5         /// <summary>  
  6         /// 根据指定的证书名和makecert全路径生成证书（包含公钥和私钥，并保存在MY存储区）  
  7         /// </summary>  
  8         /// <param name="subjectName"></param>  
  9         /// <param name="makecertPath"></param>  
 10         /// <returns></returns>  
 11         public static bool CreateCertWithPrivateKey(string subjectName, string makecertPath)  
 12         {  
 13             subjectName = "CN=" + subjectName;  
 14             string param = " -pe -ss my -n \"" + subjectName + "\" ";  
 15             try  
 16             {  
 17                 Process p = Process.Start(makecertPath, param);  
 18                 p.WaitForExit();  
 19                 p.Close();  
 20             }  
 21             catch (Exception e)  
 22             {  
 23                 LogRecord.putErrorLog(e.ToString(), "DataCerficate.CreateCertWithPrivateKey");  
 24                 return false;  
 25             }  
 26             return true;  
 27         }  
 28         #endregion  
 29  
 30         #region 文件导入导出  
 31         /// <summary>  
 32         /// 从WINDOWS证书存储区的个人MY区找到主题为subjectName的证书，  
 33         /// 并导出为pfx文件，同时为其指定一个密码  
 34         /// 并将证书从个人区删除(如果isDelFromstor为true)  
 35         /// </summary>  
 36         /// <param name="subjectName">证书主题，不包含CN=</param>  
 37         /// <param name="pfxFileName">pfx文件名</param>  
 38         /// <param name="password">pfx文件密码</param>  
 39         /// <param name="isDelFromStore">是否从存储区删除</param>  
 40         /// <returns></returns>  
 41         public static bool ExportToPfxFile(string subjectName, string pfxFileName,  
 42             string password, bool isDelFromStore)  
 43         {  
 44             subjectName = "CN=" + subjectName;  
 45             X509Store store = new X509Store(StoreName.My, StoreLocation.CurrentUser);  
 46             store.Open(OpenFlags.ReadWrite);  
 47             X509Certificate2Collection storecollection = (X509Certificate2Collection)store.Certificates;  
 48             foreach (X509Certificate2 x509 in storecollection)  
 49             {  
 50                 if (x509.Subject == subjectName)  
 51                 {  
 52                     Debug.Print(string.Format("certificate name: {0}", x509.Subject));  
 53   
 54                     byte[] pfxByte = x509.Export(X509ContentType.Pfx, password);  
 55                     using (FileStream fileStream = new FileStream(pfxFileName, FileMode.Create))  
 56                     {  
 57                         // Write the data to the file, byte by byte.  
 58                         for (int i = 0; i < pfxByte.Length; i++)  
 59                             fileStream.WriteByte(pfxByte[i]);  
 60                         // Set the stream position to the beginning of the file.  
 61                         fileStream.Seek(0, SeekOrigin.Begin);  
 62                         // Read and verify the data.  
 63                         for (int i = 0; i < fileStream.Length; i++)  
 64                         {  
 65                             if (pfxByte[i] != fileStream.ReadByte())  
 66                             {  
 67                                 LogRecord.putErrorLog("Export pfx error while verify the pfx file!", "ExportToPfxFile");  
 68                                 fileStream.Close();  
 69                                 return false;  
 70                             }  
 71                         }  
 72                         fileStream.Close();  
 73                     }  
 74                     if( isDelFromStore == true)  
 75                         store.Remove(x509);  
 76                 }  
 77             }  
 78             store.Close();  
 79             store = null;  
 80             storecollection = null;  
 81             return true;  
 82         }  
 83         /// <summary>  
 84         /// 从WINDOWS证书存储区的个人MY区找到主题为subjectName的证书，  
 85         /// 并导出为CER文件（即，只含公钥的）  
 86         /// </summary>  
 87         /// <param name="subjectName"></param>  
 88         /// <param name="cerFileName"></param>  
 89         /// <returns></returns>  
 90         public static bool ExportToCerFile(string subjectName, string cerFileName)  
 91         {  
 92             subjectName = "CN=" + subjectName;  
 93             X509Store store = new X509Store(StoreName.My, StoreLocation.CurrentUser);  
 94             store.Open(OpenFlags.ReadWrite);  
 95             X509Certificate2Collection storecollection = (X509Certificate2Collection)store.Certificates;  
 96             foreach (X509Certificate2 x509 in storecollection)  
 97             {  
 98                 if (x509.Subject == subjectName)  
 99                 {  
100                     Debug.Print(string.Format("certificate name: {0}", x509.Subject));  
101                     //byte[] pfxByte = x509.Export(X509ContentType.Pfx, password);  
102                     byte[] cerByte = x509.Export(X509ContentType.Cert);  
103                     using (FileStream fileStream = new FileStream(cerFileName, FileMode.Create))  
104                     {  
105                         // Write the data to the file, byte by byte.  
106                         for (int i = 0; i < cerByte.Length; i++)  
107                             fileStream.WriteByte(cerByte[i]);  
108                         // Set the stream position to the beginning of the file.  
109                         fileStream.Seek(0, SeekOrigin.Begin);  
110                         // Read and verify the data.  
111                         for (int i = 0; i < fileStream.Length; i++)  
112                         {  
113                             if (cerByte[i] != fileStream.ReadByte())  
114                             {  
115                                 LogRecord.putErrorLog("Export CER error while verify the CERT file!", "ExportToCERFile");  
116                                 fileStream.Close();  
117                                 return false;  
118                             }  
119                         }  
120                         fileStream.Close();  
121                     }  
122                 }  
123             }  
124             store.Close();  
125             store = null;  
126             storecollection = null;  
127             return true;  
128         }  
129         #endregion  
130  
131         #region 从证书中获取信息  
132         /// <summary>  
133         /// 根据私钥证书得到证书实体，得到实体后可以根据其公钥和私钥进行加解密  
134         /// 加解密函数使用DEncrypt的RSACryption类  
135         /// </summary>  
136         /// <param name="pfxFileName"></param>  
137         /// <param name="password"></param>  
138         /// <returns></returns>  
139         public static X509Certificate2 GetCertificateFromPfxFile(string pfxFileName,  
140             string password)  
141         {  
142             try  
143             {  
144                 return new X509Certificate2(pfxFileName, password, X509KeyStorageFlags.Exportable);  
145             }  
146             catch (Exception e)  
147             {  
148                 LogRecord.putErrorLog("get certificate from pfx" + pfxFileName + " error:" + e.ToString(),  
149                     "GetCertificateFromPfxFile");  
150                 return null;  
151             }  
152         }  
153         /// <summary>  
154         /// 到存储区获取证书  
155         /// </summary>  
156         /// <param name="subjectName"></param>  
157         /// <returns></returns>  
158         public static X509Certificate2 GetCertificateFromStore(string subjectName)  
159         {  
160             subjectName = "CN=" + subjectName;  
161             X509Store store = new X509Store(StoreName.My, StoreLocation.CurrentUser);  
162             store.Open(OpenFlags.ReadWrite);  
163             X509Certificate2Collection storecollection = (X509Certificate2Collection)store.Certificates;  
164             foreach (X509Certificate2 x509 in storecollection)  
165             {  
166                 if (x509.Subject == subjectName)  
167                 {  
168                     return x509;  
169                 }  
170             }  
171             store.Close();  
172             store = null;  
173             storecollection = null;  
174             return null;  
175         }  
176         /// <summary>  
177         /// 根据公钥证书，返回证书实体  
178         /// </summary>  
179         /// <param name="cerPath"></param>  
180         public static X509Certificate2 GetCertFromCerFile(string cerPath)  
181         {  
182             try  
183             {  
184                 return new X509Certificate2(cerPath);  
185             }  
186             catch (Exception e)  
187             {  
188                 LogRecord.putErrorLog(e.ToString(), "DataCertificate.LoadStudentPublicKey");  
189                 return null;  
190             }              
191         }  
192         #endregion         
193     }  
194 

转自:http://blog.csdn.net/luminji/archive/2009/03/05/3960308.aspx