connectionString加密

首先是加密，解密類。

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Security.Cryptography;
using System.Text;
using System.Threading.Tasks;

namespace SqlConnectionEncryp
{
    public class Encrypt
    {
        /// <summary> 
        ///  MD5加密 
        /// </summary> 
        public static string MD5Encrypt(string Text, string sKey)
        {
            DESCryptoServiceProvider des = new DESCryptoServiceProvider();
            byte[] inputByteArray = Encoding.Default.GetBytes(Text);
            des.Key = ASCIIEncoding.ASCII.GetBytes(System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(sKey, "md5").Substring(0, 8));
            des.IV = ASCIIEncoding.ASCII.GetBytes(System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(sKey, "md5").Substring(0, 8));
            System.IO.MemoryStream ms = new System.IO.MemoryStream();
            CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(), CryptoStreamMode.Write);
            cs.Write(inputByteArray, 0, inputByteArray.Length);
            cs.FlushFinalBlock();
            StringBuilder ret = new StringBuilder();
            foreach (byte b in ms.ToArray())
            {
                ret.AppendFormat("{0:X2}", b);
            }
            return ret.ToString();
        }

        /// <summary> 
        ///  MD5解密
        /// </summary>  
        public static string MD5Decrypt(string Text, string sKey)
        {
            DESCryptoServiceProvider des = new DESCryptoServiceProvider();
            int len;
            len = Text.Length / 2;
            byte[] inputByteArray = new byte[len];
            int x, i;
            for (x = 0; x < len; x++)
            {
                i = Convert.ToInt32(Text.Substring(x * 2, 2), 16);
                inputByteArray[x] = (byte)i;
            }
            des.Key = ASCIIEncoding.ASCII.GetBytes(System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(sKey, "md5").Substring(0, 8));
            des.IV = ASCIIEncoding.ASCII.GetBytes(System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(sKey, "md5").Substring(0, 8));
            System.IO.MemoryStream ms = new System.IO.MemoryStream();
            CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(), CryptoStreamMode.Write);
            cs.Write(inputByteArray, 0, inputByteArray.Length);
            cs.FlushFinalBlock();
            return Encoding.Default.GetString(ms.ToArray());
        }


        /// <summary>
        /// TripleDES加密
        /// </summary>
        public static string TripleDESEncrypting(string strSource)
        {
            try
            {
                byte[] bytIn = Encoding.Default.GetBytes(strSource);
                byte[] key = { 42, 16, 93, 156, 78, 4, 218, 32, 15, 167, 44, 80, 26, 20, 155, 112, 2, 94, 11, 204, 119, 35, 184, 197 }; //定義密鑰
                byte[] IV = { 55, 103, 246, 79, 36, 99, 167, 3 };  //定義偏移量
                TripleDESCryptoServiceProvider TripleDES = new TripleDESCryptoServiceProvider();
                TripleDES.IV = IV;
                TripleDES.Key = key;
                ICryptoTransform encrypto = TripleDES.CreateEncryptor();
                System.IO.MemoryStream ms = new System.IO.MemoryStream();
                CryptoStream cs = new CryptoStream(ms, encrypto, CryptoStreamMode.Write);
                cs.Write(bytIn, 0, bytIn.Length);
                cs.FlushFinalBlock();
                byte[] bytOut = ms.ToArray();
                return System.Convert.ToBase64String(bytOut);
            }
            catch (Exception ex)
            {
                throw new Exception("加密時候出現錯誤!錯誤提示:\n" + ex.Message);
            }
        }

        /// <summary>
        /// TripleDES解密
        /// </summary>
        public static string TripleDESDecrypting(string Source)
        {
            try
            {
                byte[] bytIn = System.Convert.FromBase64String(Source);
                byte[] key = { 42, 16, 93, 156, 78, 4, 218, 32, 15, 167, 44, 80, 26, 20, 155, 112, 2, 94, 11, 204, 119, 35, 184, 197 }; //定義密鑰
                byte[] IV = { 55, 103, 246, 79, 36, 99, 167, 3 };   //定義偏移量
                TripleDESCryptoServiceProvider TripleDES = new TripleDESCryptoServiceProvider();
                TripleDES.IV = IV;
                TripleDES.Key = key;
                ICryptoTransform encrypto = TripleDES.CreateDecryptor();
                System.IO.MemoryStream ms = new System.IO.MemoryStream(bytIn, 0, bytIn.Length);
                CryptoStream cs = new CryptoStream(ms, encrypto, CryptoStreamMode.Read);
                StreamReader strd = new StreamReader(cs, Encoding.Default);
                return strd.ReadToEnd();
            }
            catch (Exception ex)
            {
                throw new Exception("解密時候出現錯誤!錯誤提示:\n" + ex.Message);
            }
        }
    }
}

View Code

加密使用MD5Decrypt，本身給定一個密鑰。下面是對鏈接字符串加密的界面：

代碼和測試效果：

public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void btnCreate_Click(object sender, EventArgs e)
        {
            if (string.IsNullOrEmpty(txtClear.Text))
            {
                MessageBox.Show("明文不能爲空！");
            }
            if (string.IsNullOrEmpty(txtKey.Text))
            {
                MessageBox.Show("密鑰不能爲空！");
            }

            string strCipher = Encrypt.MD5Encrypt(txtClear.Text, txtKey.Text);
            txtCipher.Text = strCipher;
        }
    }

View Code

加密的緣由是，爲客戶開發的某些程序，須要訪問公司（咱們本身工做的）在公網的數據庫，可是咱們不能將明文數據庫訪問字符串，存放在客戶的應用程序上，最好的辦法就是將其加密。下面就在一個爲客戶開發的程序中使用這個加密鏈接。這裏，我將密鑰和密文都寫在了配置文件中。若是用戶猜出個人加密算法，他們能夠根據密鑰，能夠輕鬆得到個人明文。因此，不要傻到直接將密鑰配置命名成key。若是將密鑰寫死在代碼中就不方便控制，客戶反編譯一樣能獲知加密算法和密鑰，從而得到原本的鏈接字符串。

下面在獲取鏈接字符串時，都要對其進行解密，因此構造一個解密類是必要的。

public class ConfigHelper
    {
        /// <summary>
        /// 獲取普通鏈接
        /// </summary>
        public static string GetConn(string conn)
        {
            return ConfigurationManager.ConnectionStrings[conn].ConnectionString;
        }
        /// <summary>
        /// 獲取appsetting
        /// </summary>
        public static string GetAppSetting(string key)
        {
            return ConfigurationManager.AppSettings[key];
        }
        /// <summary>
        /// 獲取解密鏈接
        /// </summary>
        public static string GetConn(string conn, string key)
        {
            string strConn = GetConn(conn);
            string strKey = GetAppSetting(key);
            return MD5Decrypt(strConn, strKey);
        }

        /// <summary> 
        ///  MD5解密
        /// </summary>  
        private static string MD5Decrypt(string Text, string sKey)
        {
            DESCryptoServiceProvider des = new DESCryptoServiceProvider();
            int len;
            len = Text.Length / 2;
            byte[] inputByteArray = new byte[len];
            int x, i;
            for (x = 0; x < len; x++)
            {
                i = Convert.ToInt32(Text.Substring(x * 2, 2), 16);
                inputByteArray[x] = (byte)i;
            }
            des.Key = ASCIIEncoding.ASCII.GetBytes(System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(sKey, "md5").Substring(0, 8));
            des.IV = ASCIIEncoding.ASCII.GetBytes(System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(sKey, "md5").Substring(0, 8));
            System.IO.MemoryStream ms = new System.IO.MemoryStream();
            CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(), CryptoStreamMode.Write);
            cs.Write(inputByteArray, 0, inputByteArray.Length);
            cs.FlushFinalBlock();
            return Encoding.Default.GetString(ms.ToArray());
        }
    }

View Code

下面是解密效果，若是客戶不是專業人士，咱們公網數據庫鏈接就是安全的了：