从自签名证书导出pfx和cer证书

完整代码：

 public sealed class DataCertificate
     {
         #region 生成证书
         /// <summary>
         /// 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）
         /// </summary>
         /// <param name="subjectName"></param>
         /// <param name="makecertPath"></param>
         /// <returns></returns>
         public static bool CreateCertWithPrivateKey(string subjectName, string makecertPath)
         {
             subjectName = "CN=" + subjectName;
             string param = " -pe -ss my -n \"" + subjectName + "\" ";
             try
             {
                 Process p = Process.Start(makecertPath, param);
                 p.WaitForExit();
                 p.Close();
             }
             catch (Exception e)
             {
                 return false;
             }
             return true;
         }
         #endregion

         #region 文件导入导出
         /// <summary>
         /// 从WINDOWS证书存储区的个人MY区找到主题为subjectName的证书，
         /// 并导出为pfx文件，同时为其指定一个密码
         /// 并将证书从个人区删除(如果isDelFromstor为true)
         /// </summary>
         /// <param name="subjectName">证书主题，不包含CN=</param>
         /// <param name="pfxFileName">pfx文件名</param>
         /// <param name="password">pfx文件密码</param>
         /// <param name="isDelFromStore">是否从存储区删除</param>
         /// <returns></returns>
         public static bool ExportToPfxFile(string subjectName, string pfxFileName,
             string password, bool isDelFromStore)
         {
             subjectName = "CN=" + subjectName;
             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 == subjectName)
                 {
                     Debug.Print(string.Format("certificate name: {0}", x509.Subject));

                     byte[] pfxByte = x509.Export(X509ContentType.Pfx, password);
                     using (FileStream fileStream = new FileStream(pfxFileName, FileMode.Create))
                     {
                         // Write the data to the file, byte by byte.
                         for (int i = ; i < pfxByte.Length; i++)
                             fileStream.WriteByte(pfxByte[i]);
                         // Set the stream position to the beginning of the file.
                         fileStream.Seek(, SeekOrigin.Begin);
                         // Read and verify the data.
                         for (int i = ; i < fileStream.Length; i++)
                         {
                             if (pfxByte[i] != fileStream.ReadByte())
                             {
                                 fileStream.Close();
                                 return false;
                             }
                         }
                         fileStream.Close();
                     }
                     if (isDelFromStore == true)
                         store.Remove(x509);
                 }
             }
             store.Close();
             return true;
         }
         /// <summary>
         /// 从WINDOWS证书存储区的个人MY区找到主题为subjectName的证书，
         /// 并导出为CER文件（即，只含公钥的）
         /// </summary>
         /// <param name="subjectName"></param>
         /// <param name="cerFileName"></param>
         /// <returns></returns>
         public static bool ExportToCerFile(string subjectName, string cerFileName)
         {
             subjectName = "CN=" + subjectName;
             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 == subjectName)
                 {
                     Debug.Print(string.Format("certificate name: {0}", x509.Subject));
                     //byte[] pfxByte = x509.Export(X509ContentType.Pfx, password);
                     byte[] cerByte = x509.Export(X509ContentType.Cert);
                     using (FileStream fileStream = new FileStream(cerFileName, FileMode.Create))
                     {
                         // Write the data to the file, byte by byte.
                         for (int i = ; i < cerByte.Length; i++)
                             fileStream.WriteByte(cerByte[i]);
                         // Set the stream position to the beginning of the file.
                         fileStream.Seek(, SeekOrigin.Begin);
                         // Read and verify the data.
                         for (int i = ; i < fileStream.Length; i++)
                         {
                             if (cerByte[i] != fileStream.ReadByte())
                             {
                                 fileStream.Close();
                                 return false;
                             }
                         }
                         fileStream.Close();
                     }
                 }
             }
             store.Close();
             store = null;
             storecollection = null;
             return true;
         }
         #endregion

         #region 从证书中获取信息
         /// <summary>
         /// 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
         /// 加解密函数使用DEncrypt的RSACryption类
         /// </summary>
         /// <param name="pfxFileName"></param>
         /// <param name="password"></param>
         /// <returns></returns>
         public static X509Certificate2 GetCertificateFromPfxFile(string pfxFileName,
             string password)
         {
             try
             {
                 return new X509Certificate2(pfxFileName, password, X509KeyStorageFlags.Exportable);
             }
             catch (Exception e)
             {
                 return null;
             }
         }
         /// <summary>
         /// 到存储区获取证书
         /// </summary>
         /// <param name="subjectName"></param>
         /// <returns></returns>
         public static X509Certificate2 GetCertificateFromStore(string subjectName)
         {
             subjectName = "CN=" + subjectName;
             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 == subjectName)
                 {
                     return x509;
                 }
             }
             store.Close();
             store = null;
             storecollection = null;
             return null;
         }
         /// <summary>
         /// 根据公钥证书，返回证书实体
         /// </summary>
         /// <param name="cerPath"></param>
         public static X509Certificate2 GetCertFromCerFile(string cerPath)
         {
             try
             {
                 return new X509Certificate2(cerPath);
             }
             catch (Exception e)
             {
                 return null;
             }
         }
         #endregion
     }