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；

 

系统界面：

代码如下：

06. /// 07. private void btn_toPfxFile_Click( object sender, EventArgs e) 08. { 09. X509Store store = new X509Store(StoreName.My, StoreLocation.CurrentUser); 10. store.Open(OpenFlags.ReadWrite); 11. X509Certificate2Collection storecollection = (X509Certificate2Collection)store.Certificates; 12. foreach (X509Certificate2 x509 in storecollection) 13. { 14. if (x509.Subject == " CN=luminji") 15. { 16. Debug.Print( string.Format(" certificate name: {0}", x509.Subject)); 17. byte[] pfxByte = x509.Export(X509ContentType.Pfx, " 123"); 18. using (FileStream fileStream = new FileStream(" luminji.pfx", FileMode.Create)) 19. { 20. // Write the data to the file, byte by byte. 21. for ( int i = 0; i < pfxByte.Length; i++) 22. fileStream.WriteByte(pfxByte[i]); 23. // Set the stream position to the beginning of the file. 24. fileStream.Seek(0, SeekOrigin.Begin); 25. // Read and verify the data. 26. for ( int i = 0; i < fileStream.Length; i++) 27. { 28. if (pfxByte[i] != fileStream.ReadByte()) 29. { 30. Debug.Print(" Error writing data."); 31. return; 32. } 33. } 34. fileStream.Close(); 35. Debug.Print(" The data was written to {0} " + 36. " and verified.", fileStream.Name); 37. } 38. string myname = " my name is luminji! and i love huzhonghua!"; 39. string enStr = this.RSAEncrypt(x509.PublicKey.Key.ToXmlString( false), myname); 40. MessageBox.Show(" 密文是：" + enStr); 41. string deStr = this.RSADecrypt(x509.PrivateKey.ToXmlString( true), enStr); 42. MessageBox.Show(" 明文是：" + deStr); 43. } 44. } 45. store.Close(); 46. store = null; 47. storecollection = null; 48. } 49. /// 50. /// 创建还有私钥的证书 51. /// 52. /// 53. /// 54. private void btn_createPfx_Click( object sender, EventArgs e) 55. { 56. string MakeCert = " C:\\Program Files\\Microsoft Visual Studio 8\\SDK\\v2.0\\Bin\\makecert.exe"; 57. string x509Name = " CN=luminji"; 58. string param = " -pe -ss my -n \"" + x509Name + " \" " ; 59. Process p = Process.Start(MakeCert, param); 60. p.WaitForExit(); 61. p.Close(); 62. MessageBox.Show(" over"); 63. } 64. /// 65. /// 从pfx文件读取证书信息 66. /// 67. /// 68. /// 69. private void btn_readFromPfxFile( object sender, EventArgs e) 70. { 71. X509Certificate2 pc = new X509Certificate2(" luminji.pfx", " 123"); 72. MessageBox.Show(" name:" + pc.SubjectName.Name); 73. MessageBox.Show(" public:" + pc.PublicKey.ToString()); 74. MessageBox.Show(" private:" + pc.PrivateKey.ToString()); 75. pc = null; 76. } 77. /// 78. /// RSA解密 79. /// 80. /// 81. /// 82. /// 83. public string RSADecrypt( string xmlPrivateKey, string m_strDecryptString) 84. { 85. RSACryptoServiceProvider provider = new RSACryptoServiceProvider(); 86. provider.FromXmlString(xmlPrivateKey); 87. byte[] rgb = Convert.FromBase64String(m_strDecryptString); 88. byte[] bytes = provider.Decrypt(rgb, false); 89. return new UnicodeEncoding().GetString(bytes); 90. } 91. /// 92. /// RSA加密 93. /// 94. /// 95. /// 96. /// 97. public string RSAEncrypt( string xmlPublicKey, string m_strEncryptString) 98. { 99. RSACryptoServiceProvider provider = new RSACryptoServiceProvider(); 100. provider.FromXmlString(xmlPublicKey); 101. byte[] bytes = new UnicodeEncoding().GetBytes(m_strEncryptString); 102. return Convert.ToBase64String(provider.Encrypt(bytes, false)); 103. }

 

上文是一个示例程序，一个完整的证书工具类如下：

08. /// 09. /// 10. public static bool CreateCertWithPrivateKey( string subjectName, string makecertPath) 11. { 12. subjectName = " CN=" + subjectName; 13. string param = " -pe -ss my -n \"" + subjectName + " \" "; 14. try 15. { 16. Process p = Process.Start(makecertPath, param); 17. p.WaitForExit(); 18. p.Close(); 19. } 20. catch (Exception e) 21. { 22. LogRecord.putErrorLog(e.ToString(), " DataCerficate.CreateCertWithPrivateKey"); 23. return false; 24. } 25. return true; 26. } 27. #endregion 28. 29. #region 文件导入导出 30. /// 31. /// 从WINDOWS证书存储区的个人MY区找到主题为subjectName的证书， 32. /// 并导出为pfx文件，同时为其指定一个密码 33. /// 并将证书从个人区删除(如果isDelFromstor为true) 34. /// 35. /// 证书主题，不包含CN= 36. /// pfx文件名 37. /// pfx文件密码 38. /// 是否从存储区删除 39. /// 40. public static bool ExportToPfxFile( string subjectName, string pfxFileName, 41. string password, bool isDelFromStore) 42. { 43. subjectName = " CN=" + subjectName; 44. X509Store store = new X509Store(StoreName.My, StoreLocation.CurrentUser); 45. store.Open(OpenFlags.ReadWrite); 46. X509Certificate2Collection storecollection = (X509Certificate2Collection)store.Certificates; 47. foreach (X509Certificate2 x509 in storecollection) 48. { 49. if (x509.Subject == subjectName) 50. { 51. Debug.Print( string.Format(" certificate name: {0}", x509.Subject)); 52. 53. byte[] pfxByte = x509.Export(X509ContentType.Pfx, password); 54. using (FileStream fileStream = new FileStream(pfxFileName, FileMode.Create)) 55. { 56. // Write the data to the file, byte by byte. 57. for ( int i = 0; i < pfxByte.Length; i++) 58. fileStream.WriteByte(pfxByte[i]); 59. // Set the stream position to the beginning of the file. 60. fileStream.Seek(0, SeekOrigin.Begin); 61. // Read and verify the data. 62. for ( int i = 0; i < fileStream.Length; i++) 63. { 64. if (pfxByte[i] != fileStream.ReadByte()) 65. { 66. LogRecord.putErrorLog(" Export pfx error while verify the pfx file!", " ExportToPfxFile"); 67. fileStream.Close(); 68. return false; 69. } 70. } 71. fileStream.Close(); 72. } 73. if( isDelFromStore == true) 74. store.Remove(x509); 75. } 76. } 77. store.Close(); 78. store = null; 79. storecollection = null; 80. return true; 81. } 82. /// 83. /// 从WINDOWS证书存储区的个人MY区找到主题为subjectName的证书， 84. /// 并导出为CER文件（即，只含公钥的） 85. /// 86. /// 87. /// 88. /// 89. public static bool ExportToCerFile( string subjectName, string cerFileName) 90. { 91. subjectName = " CN=" + subjectName; 92. X509Store store = new X509Store(StoreName.My, StoreLocation.CurrentUser); 93. store.Open(OpenFlags.ReadWrite); 94. X509Certificate2Collection storecollection = (X509Certificate2Collection)store.Certificates; 95. foreach (X509Certificate2 x509 in storecollection) 96. { 97. if (x509.Subject == subjectName) 98. { 99. Debug.Print( string.Format(" certificate name: {0}", x509.Subject)); 100. //byte[] pfxByte = x509.Export(X509ContentType.Pfx, password); 101. byte[] cerByte = x509.Export(X509ContentType.Cert); 102. using (FileStream fileStream = new FileStream(cerFileName, FileMode.Create)) 103. { 104. // Write the data to the file, byte by byte. 105. for ( int i = 0; i < cerByte.Length; i++) 106. fileStream.WriteByte(cerByte[i]); 107. // Set the stream position to the beginning of the file. 108. fileStream.Seek(0, SeekOrigin.Begin); 109. // Read and verify the data. 110. for ( int i = 0; i < fileStream.Length; i++) 111. { 112. if (cerByte[i] != fileStream.ReadByte()) 113. { 114. LogRecord.putErrorLog(" Export CER error while verify the CERT file!", " ExportToCERFile"); 115. fileStream.Close(); 116. return false; 117. } 118. } 119. fileStream.Close(); 120. } 121. } 122. } 123. store.Close(); 124. store = null; 125. storecollection = null; 126. return true; 127. } 128. #endregion 129. 130. #region 从证书中获取信息 131. /// 132. /// 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 133. /// 加解密函数使用DEncrypt的RSACryption类 134. /// 135. /// 136. /// 137. /// 138. public static X509Certificate2 GetCertificateFromPfxFile( string pfxFileName, 139. string password) 140. { 141. try 142. { 143. return new X509Certificate2(pfxFileName, password, X509KeyStorageFlags.Exportable); 144. } 145. catch (Exception e) 146. { 147. LogRecord.putErrorLog(" get certificate from pfx" + pfxFileName + " error:" + e.ToString(), 148. " GetCertificateFromPfxFile"); 149. return null; 150. } 151. } 152. /// 153. /// 到存储区获取证书 154. /// 155. /// 156. /// 157. public static X509Certificate2 GetCertificateFromStore( string subjectName) 158. { 159. subjectName = " CN=" + subjectName; 160. X509Store store = new X509Store(StoreName.My, StoreLocation.CurrentUser); 161. store.Open(OpenFlags.ReadWrite); 162. X509Certificate2Collection storecollection = (X509Certificate2Collection)store.Certificates; 163. foreach (X509Certificate2 x509 in storecollection) 164. { 165. if (x509.Subject == subjectName) 166. { 167. return x509; 168. } 169. } 170. store.Close(); 171. store = null; 172. storecollection = null; 173. return null; 174. } 175. /// 176. /// 根据公钥证书，返回证书实体 177. /// 178. /// 179. public static X509Certificate2 GetCertFromCerFile( string cerPath) 180. { 181. try 182. { 183. return new X509Certificate2(cerPath); 184. } 185. catch (Exception e) 186. { 187. LogRecord.putErrorLog(e.ToString(), " DataCertificate.LoadStudentPublicKey"); 188. return null; 189. } 190. } 191. #endregion 192. }