C#创建数字证书并导出为pfx，并使用pfx进行非对称加解密

摘自: http://blog.csdn.net/yezheng5419/article/details/4263914

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：

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/// <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>
        privatevoid 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>
        privatevoid 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>
        privatevoid 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>
        publicstring 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);
            returnnew UnicodeEncoding().GetString(bytes);
        }
        /// <summary>
        /// RSA加密
        /// </summary>
        /// <param name="xmlPublicKey"></param>
        /// <param name="m_strEncryptString"></param>
        /// <returns></returns>
        publicstring 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));
        }