C# 使用DES加密，解密字符串

1 DES类

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

namespace NoticeBoard
{
    /// <summary>
    /// DES加密解密算法
    /// </summary>
    public class DES
    {
        /// <summary>
        /// DES加密算法
        /// sKey为8位或16位
        /// </summary>
        /// <param name="pToEncrypt">需要加密的字符串</param>
        /// <param name="sKey">密钥</param>
        /// <returns></returns>
        public string DesEncrypt(string pToEncrypt, string sKey)
        {
            StringBuilder ret = new StringBuilder();

            try
            {
                DESCryptoServiceProvider des = new DESCryptoServiceProvider();
                byte[] inputByteArray = Encoding.Default.GetBytes(pToEncrypt);
                des.Key = ASCIIEncoding.ASCII.GetBytes(sKey);
                des.IV = ASCIIEncoding.ASCII.GetBytes(sKey);
                MemoryStream ms = new MemoryStream();
                CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(), CryptoStreamMode.Write);
                cs.Write(inputByteArray, 0, inputByteArray.Length);
                cs.FlushFinalBlock();

                foreach (byte b in ms.ToArray())
                {
                    ret.AppendFormat("{0:X2}", b);
                }
                ret.ToString();
            }
            catch
            {

            }
            return ret.ToString();
            //return a;
        }
        /// <summary>
        /// DES解密算法
        /// sKey为8位或16位
        /// </summary>
        /// <param name="pToDecrypt">需要解密的字符串</param>
        /// <param name="sKey">密钥</param>
        /// <returns></returns>
        public string DesDecrypt(string pToDecrypt, string sKey)
        {
            MemoryStream ms = new MemoryStream();

            try
            {
                DESCryptoServiceProvider des = new DESCryptoServiceProvider();
                byte[] inputByteArray = new byte[pToDecrypt.Length / 2];
                for (int x = 0; x < pToDecrypt.Length / 2; x++)
                {
                    int i = (Convert.ToInt32(pToDecrypt.Substring(x * 2, 2), 16));
                    inputByteArray[x] = (byte)i;
                }
                des.Key = ASCIIEncoding.ASCII.GetBytes(sKey);
                des.IV = ASCIIEncoding.ASCII.GetBytes(sKey);

                CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(), CryptoStreamMode.Write);
                cs.Write(inputByteArray, 0, inputByteArray.Length);
                cs.FlushFinalBlock();
                StringBuilder ret = new StringBuilder();

            }
            catch
            {

            } 

            return System.Text.Encoding.Default.GetString(ms.ToArray());
        }
    }

    /// <summary>  
    /// 对称加密解密算法类  
    /// </summary>  
    public class Rijndael
    {
        private SymmetricAlgorithm mobjCryptoService;
        private string Key;
        /// <summary>  
        /// 对称加密类的构造函数  
        /// </summary>  
        public void SymmetricMethod()
        {
            mobjCryptoService = new RijndaelManaged();
            Key = "Guz(%&hj7x89H$yuBI0456FtmaT5&fvHUFCy76*h%(HilJ$lhj!y6&(*jkP87jH7";
        }
        /// <summary>  
        /// 获得密钥  
        /// </summary>  
        /// <returns>密钥</returns>  
        private byte[] GetLegalKey()
        {
            string sTemp = Key;
            mobjCryptoService.GenerateKey();
            byte[] bytTemp = mobjCryptoService.Key;
            int KeyLength = bytTemp.Length;
            if (sTemp.Length > KeyLength)
                sTemp = sTemp.Substring(0, KeyLength);
            else if (sTemp.Length < KeyLength)
                sTemp = sTemp.PadRight(KeyLength, ' ');
            return ASCIIEncoding.ASCII.GetBytes(sTemp);
        }
        /// <summary>  
        /// 获得初始向量IV  
        /// </summary>  
        /// <returns>初试向量IV</returns>  
        private byte[] GetLegalIV()
        {
            string sTemp = "aclejaspwejgjdjfasrweojksdf$%#@!^[email protected]&#*ajke^[email protected]#jka";     //key 随便写。。
            mobjCryptoService.GenerateIV();
            byte[] bytTemp = mobjCryptoService.IV;
            int IVLength = bytTemp.Length;
            if (sTemp.Length > IVLength)
                sTemp = sTemp.Substring(0, IVLength);
            else if (sTemp.Length < IVLength)
                sTemp = sTemp.PadRight(IVLength, ' ');
            return ASCIIEncoding.ASCII.GetBytes(sTemp);
        }
        /// <summary>  
        /// 加密方法  
        /// </summary>  
        /// <param name="Source">待加密的串</param>  
        /// <returns>经过加密的串</returns>  
        public string Encrypto(string Source)
        {
            byte[] bytIn = UTF8Encoding.UTF8.GetBytes(Source);
            MemoryStream ms = new MemoryStream();
            mobjCryptoService.Key = GetLegalKey();
            mobjCryptoService.IV = GetLegalIV();
            ICryptoTransform encrypto = mobjCryptoService.CreateEncryptor();
            CryptoStream cs = new CryptoStream(ms, encrypto, CryptoStreamMode.Write);
            cs.Write(bytIn, 0, bytIn.Length);
            cs.FlushFinalBlock();
            ms.Close();
            byte[] bytOut = ms.ToArray();
            return Convert.ToBase64String(bytOut);
        }
        /// <summary>  
        /// 解密方法  
        /// </summary>  
        /// <param name="Source">待解密的串</param>  
        /// <returns>经过解密的串</returns>  
        public string Decrypto(string Source)
        {
            byte[] bytIn = Convert.FromBase64String(Source);
            MemoryStream ms = new MemoryStream(bytIn, 0, bytIn.Length);
            mobjCryptoService.Key = GetLegalKey();
            mobjCryptoService.IV = GetLegalIV();
            ICryptoTransform encrypto = mobjCryptoService.CreateDecryptor();
            CryptoStream cs = new CryptoStream(ms, encrypto, CryptoStreamMode.Read);
            StreamReader sr = new StreamReader(cs);
            return sr.ReadToEnd();
        }
    }

}

2 DES加解密方法静态封装

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;
using System.Windows.Forms;
using System.Xml;

namespace NoticeBoard
{
    public class StaticClass
    {

        #region 加密解密

        public static DES dd = new DES();

        public static string StringKey = "A123456."; // 加密密钥

        /// <summary>
        /// 解密
        /// </summary>
        /// <param name="str"></param>
        /// <returns></returns>
        public static string StringDecder(string str)
        {
            return dd.DesDecrypt(str, StringKey);
        }

        /// <summary>
        /// 加密
        /// </summary>
        /// <param name="str"></param>
        /// <returns></returns>
        public static string StringEncoder(string str)
        {
            return dd.DesEncrypt(str, StringKey);
        }

        #endregion 

    }
}

3 方法调用:

直接调用 StringDecder 和 StringEncoder 方法就行了