3DES封装类

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

/// <summary>
/// 3DES加解密类
/// </summary>
public class TriDES
{
//密钥
//sKey必须使用英文字符，区分大小写，且字符数量是8个，不能多也不能少，否则出错。
private const string sKey = "CaeHuGnh";

//矢量，矢量可以为空
private const string sIV = "neCgHahU";

/// <summary>
/// 使用3DES加密字符串
/// </summary>
/// <param name="_ToEntryptString">需要加密的字符串</param>
/// <returns>加密结果字符串</returns>
public static string Encrypt(string _ToEntryptString)
{
DESCryptoServiceProvider des = new DESCryptoServiceProvider();
//把字符串放到byte数组中
byte[] inputByteArray = Encoding.Default.GetBytes(_ToEntryptString);
//建立加密对象的密钥和偏移量
des.Key = ASCIIEncoding.ASCII.GetBytes(sKey);
des.IV = ASCIIEncoding.ASCII.GetBytes(sIV);
MemoryStream ms = new 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);
}
ret.ToString();
return ret.ToString();
}

/// <summary>
/// 解密3DES加密字符串
/// </summary>
/// <param name="_ToDecryptString">解密字符串</param>
/// <returns>解密结果字符串</returns>
public static string Decrypt(string _ToDecryptString)
{
DESCryptoServiceProvider des = new DESCryptoServiceProvider();
//Put the input string into the byte array
byte[] inputByteArray = new byte[_ToDecryptString.Length / 2];
for (int x = 0; x < _ToDecryptString.Length / 2; x++)
{
int i = (Convert.ToInt32(_ToDecryptString.Substring(x * 2, 2), 16));
inputByteArray[x] = (byte)i;
}
//建立加密对象的密钥和偏移量，此值重要，不能修改
des.Key = ASCIIEncoding.ASCII.GetBytes(sKey);
des.IV = ASCIIEncoding.ASCII.GetBytes(sIV);
MemoryStream ms = new MemoryStream();
CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(), CryptoStreamMode.Write);
//Flush the data through the crypto stream into the memory stream
cs.Write(inputByteArray, 0, inputByteArray.Length);
cs.FlushFinalBlock();
//Get the decrypted data back from the memory stream
//建立StringBuild对象，CreateDecrypt使用的是流对象，必须把解密后的文本变成流对象
StringBuilder ret = new StringBuilder();
return System.Text.Encoding.Default.GetString(ms.ToArray());
}

}