本文源程序下载：http://download.csdn.net/source/2444494
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：
/// /// 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 /// /// /// 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; } /// /// 创建还有私钥的证书 /// /// /// 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"); } /// /// 从pfx文件读取证书信息 /// /// /// 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; } /// /// RSA解密 /// /// /// /// 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); } /// /// RSA加密 /// /// /// /// 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：
public sealed class DataCertificate { #region 生成证书 /// /// 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） /// /// /// /// 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) { LogRecord.putErrorLog(e.ToString(), "DataCerficate.CreateCertWithPrivateKey"); return false; } return true; } #endregion #region 文件导入导出 /// /// 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) /// /// 证书主题，不包含CN= /// pfx文件名 /// pfx文件密码 /// 是否从存储区删除 /// 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 = 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()) { LogRecord.putErrorLog("Export pfx error while verify the pfx file!", "ExportToPfxFile"); fileStream.Close(); return false; } } fileStream.Close(); } if( isDelFromStore == true) store.Remove(x509); } } store.Close(); store = null; storecollection = null; return true; } /// /// 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） /// /// /// /// 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 = 0; i < cerByte.Length; i++) fileStream.WriteByte(cerByte[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 (cerByte[i] != fileStream.ReadByte()) { LogRecord.putErrorLog("Export CER error while verify the CERT file!", "ExportToCERFile"); fileStream.Close(); return false; } } fileStream.Close(); } } } store.Close(); store = null; storecollection = null; return true; } #endregion #region 从证书中获取信息 /// /// 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 /// /// /// /// public static X509Certificate2 GetCertificateFromPfxFile(string pfxFileName, string password) { try { return new X509Certificate2(pfxFileName, password, X509KeyStorageFlags.Exportable); } catch (Exception e) { LogRecord.putErrorLog("get certificate from pfx" + pfxFileName + " error:" + e.ToString(), "GetCertificateFromPfxFile"); return null; } } /// /// 到存储区获取证书 /// /// /// 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; } /// /// 根据公钥证书，返回证书实体 /// /// public static X509Certificate2 GetCertFromCerFile(string cerPath) { try { return new X509Certificate2(cerPath); } catch (Exception e) { LogRecord.putErrorLog(e.ToString(), "DataCertificate.LoadStudentPublicKey"); return null; } } #endregion }
