C# DES加密与解密算法实例

引入System.Web.dll,用System.Web命名空间的
pass = FormsAuthentication.HashPasswordForStoringInConfigFile(pass, "MD5");

public static string Get32MD5(string str)
        {
            byte[] b = System.Text.Encoding.Default.GetBytes(str);
            b = new System.Security.Cryptography.MD5CryptoServiceProvider().ComputeHash(b);
            string ret = "";
            for (int i = 0; i < b.Length; i++)
            {
                ret += b[i].ToString("X").PadLeft(2, '0');
            }
            return ret;
        }

先看下效果

点加密

加密出来了~

然后点解密

解密成功~就算你再次启动程序~也是一样可以的情况~

代码如下~仔细看哦 ~~我不多说明了~

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;

//添加
using System.Globalization;
using System.Security.Cryptography;

namespace WindowsApplication1
{
      public partial class Form1 : Form
      {
          public Form1()
          {
              InitializeComponent();
          }

          public string key="??^&$%^&";//随便写~
          public string s2;

          //// 创建Key
          //public string GenerateKey()
          //{
          //      DESCryptoServiceProvider desCrypto = (DESCryptoServiceProvider)DESCryptoServiceProvider.Create();
          //      return ASCIIEncoding.ASCII.GetString(desCrypto.Key);
          //}
          // 加密字符串
          public string EncryptString(string sInputString, string sKey)
          {
              byte[] data = Encoding.UTF8.GetBytes(sInputString);
              DESCryptoServiceProvider DES = new DESCryptoServiceProvider();
              DES.Key = ASCIIEncoding.ASCII.GetBytes(sKey);
              DES.IV = ASCIIEncoding.ASCII.GetBytes(sKey);
              ICryptoTransform desencrypt = DES.CreateEncryptor();
              byte[] result = desencrypt.TransformFinalBlock(data, 0, data.Length);
              return BitConverter.ToString(result);
          }
          // 解密字符串
          public string DecryptString(string sInputString, string sKey)
          {
              string[] sInput = sInputString.Split("-".ToCharArray());
              byte[] data = new byte[sInput.Length];
              for (int i = 0; i < sInput.Length; i++)
              {
                  data[i] = byte.Parse(sInput[i], NumberStyles.HexNumber);
              }
              DESCryptoServiceProvider DES = new DESCryptoServiceProvider();
              DES.Key = ASCIIEncoding.ASCII.GetBytes(sKey);
              DES.IV = ASCIIEncoding.ASCII.GetBytes(sKey);
              ICryptoTransform desencrypt = DES.CreateDecryptor();
              byte[] result = desencrypt.TransformFinalBlock(data, 0, data.Length);
              return Encoding.UTF8.GetString(result);
          }
        

          private void Form1_Load(object sender, EventArgs e)
          {

          }

          private void button1_Click(object sender, EventArgs e)
          {//加密
              textBox2.Text = EncryptString(textBox1.Text, key);
          }

          private void button2_Click(object sender, EventArgs e)
          {//解密
              textBox2.Text = DecryptString(textBox1.Text, key);
          }
      }
}

以上在VS2005中运行成功~^_^~~

#region === DESEncrypt ===

        /// <summary>
        /// 使用DES加密指定字符串
        /// </summary>
        /// <param name="encryptStr">待加密的字符串</param>
        /// <param name="key">密钥(最大长度8)</param>
        /// <param name="IV">初始化向量(最大长度8)</param>
        /// <returns>加密后的字符串</returns> 
        public static string DESEncrypt(string encryptStr, string key, string IV)
        {
            //将key和IV处理成8个字符 
            key += "12345678";
            IV += "12345678";
            key = key.Substring(0, 8);
            IV = IV.Substring(0, 8);

            SymmetricAlgorithm sa;
            ICryptoTransform ict;
            MemoryStream ms;
            CryptoStream cs;
            byte[] byt;

            sa = new DESCryptoServiceProvider();
            sa.Key = Encoding.UTF8.GetBytes(key);
            sa.IV = Encoding.UTF8.GetBytes(IV);
            ict = sa.CreateEncryptor();

            byt = Encoding.UTF8.GetBytes(encryptStr);

            ms = new MemoryStream();
            cs = new CryptoStream(ms, ict, CryptoStreamMode.Write);
            cs.Write(byt, 0, byt.Length);
            cs.FlushFinalBlock();

            cs.Close();

            //加上一些干扰字符 
            string retVal = Convert.ToBase64String(ms.ToArray());
            System.Random ra = new Random();

            for (int i = 0; i < 8; i++)
            {
                int radNum = ra.Next(36);
                char radChr = Convert.ToChar(radNum + 65);//生成一个随机字符 

                retVal = retVal.Substring(0, 2 * i + 1) + radChr.ToString() + retVal.Substring(2 * i + 1);
            }

            return retVal;
        }
        #endregion

        #region === DESDecrypt ===

        /// <summary>
        /// 使用DES解密指定字符串
        /// </summary>
        /// <param name="encryptedValue">待解密的字符串</param>
        /// <param name="key">密钥(最大长度8)</param>
        /// <param name="IV">初始化向量(最大长度8)</param>
        /// <returns>解密后的字符串</returns> 
        public static string DESDecrypt(string encryptedValue, string key, string IV)
        {

            //去掉干扰字符 
            string tmp = encryptedValue;
            if (tmp.Length < 16)
            {
                return "";
            }
            for (int i = 0; i < 8; i++)
            {
                tmp = tmp.Substring(0, i + 1) + tmp.Substring(i + 2);
            }
            encryptedValue = tmp;

            //将key和IV处理成8个字符 
            key += "12345678";
            IV += "12345678";
            key = key.Substring(0, 8);
            IV = IV.Substring(0, 8);

            SymmetricAlgorithm sa;
            ICryptoTransform ict;
            MemoryStream ms;
            CryptoStream cs;
            byte[] byt;

            try
            {
               
                sa = new DESCryptoServiceProvider();
               
                sa.Key = Encoding.UTF8.GetBytes(key);
             
                sa.IV = Encoding.UTF8.GetBytes(IV);
             
                ict = sa.CreateDecryptor();

                byt = Convert.FromBase64String(encryptedValue);

                ms = new MemoryStream();
                cs = new CryptoStream(ms, ict, CryptoStreamMode.Write);
                cs.Write(byt, 0, byt.Length);
                cs.FlushFinalBlock();

                cs.Close();
             
                return Encoding.UTF8.GetString(ms.ToArray());
            }
            catch (System.Exception)
            {
                return "";
            }
        }
        #endregion