MD5

  /*调用
         //加密
              string password = MD5.DesEncrypt("123456");
          //解密
              string pas = MD5.DesDecrypt(password);
       
         */


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

namespace Test23
{
    /// <summary>
    /// 加密码类
    /// </summary>
  public  class MD5
    {    
            /// <summary>
            /// 加密
            /// </summary>
            /// <param name="inputString"></param>
            /// <returns></returns>
            public static string DesEncrypt(string inputString)
            {
                return DesEncrypt(inputString, Key);
            }
            /// <summary>
            /// 解密
            /// </summary>
            /// <param name="inputString"></param>
            /// <returns></returns>
            public static string DesDecrypt(string inputString)
            {
                return DesDecrypt(inputString, Key);
            }
            /// <summary>
            /// 密匙
            /// </summary>
            private static string Key
            {
                get
                {
                    return "hongye10";
                }
            }
            /// <summary>
            /// 加密字符串
            /// 注意:密钥必须为８位
            /// </summary>
            /// <param name="strText">字符串</param>
            /// <param name="encryptKey">密钥</param>
            /// <param name="encryptKey">返回加密后的字符串</param>
            public static string DesEncrypt(string inputString, string encryptKey)
            {
                byte[] byKey = null;
                byte[] IV = { 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF };
                try
                {
                    byKey = System.Text.Encoding.UTF8.GetBytes(encryptKey.Substring(0, 8));
                    DESCryptoServiceProvider des = new DESCryptoServiceProvider();
                    byte[] inputByteArray = Encoding.UTF8.GetBytes(inputString);
                    MemoryStream ms = new MemoryStream();
                    CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(byKey, IV), CryptoStreamMode.Write);
                    cs.Write(inputByteArray, 0, inputByteArray.Length);
                    cs.FlushFinalBlock();
                    return Convert.ToBase64String(ms.ToArray());
                }
                catch (System.Exception error)
                {
                    //return error.Message;
                    return null;
                }
            }
            /// <summary>
            /// 解密字符串
            /// </summary>
            /// <param name="this.inputString">加了密的字符串</param>
            /// <param name="decryptKey">密钥</param>
            /// <param name="decryptKey">返回解密后的字符串</param>
            public static string DesDecrypt(string inputString, string decryptKey)
            {
                byte[] byKey = null;
                byte[] IV = { 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF };
                byte[] inputByteArray = new Byte[inputString.Length];
                try
                {
                    byKey = System.Text.Encoding.UTF8.GetBytes(decryptKey.Substring(0, 8));
                    DESCryptoServiceProvider des = new DESCryptoServiceProvider();
                    inputByteArray = Convert.FromBase64String(inputString);
                    MemoryStream ms = new MemoryStream();
                    CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(byKey, IV), CryptoStreamMode.Write);
                    cs.Write(inputByteArray, 0, inputByteArray.Length);
                    cs.FlushFinalBlock();
                    System.Text.Encoding encoding = new System.Text.UTF8Encoding();
                    return encoding.GetString(ms.ToArray());
                }
                catch (System.Exception error)
                {
                    //return error.Message;
                    return null;
                }
            }
        }
    }