小技巧：用C＃实现Des加密和解密

Linuxmine收集整理　 作者：linux宝库 (http://www.linuxmine.com)　 时间：2006-11-06

using System;

using System.IO;
using System.Security.Cryptography;

namespace Vavic
{
/// <summary>
/// Security 的摘要说明。
/// </summary>
public class Security
{
const string KEY_64 = "VavicApp";
const string IV_64 = "VavicApp"; //注意了，是8个字符，64位

public Security()
{
//
// TODO: 在此处添加构造函数逻辑
//
}

public static string Encode(string data)
{
byte[] byKey = System.Text.ASCIIEncoding.ASCII.GetBytes(KEY_64);
byte[] byIV = System.Text.ASCIIEncoding.ASCII.GetBytes(IV_64);

DESCryptoServiceProvider cryptoProvider = new
DESCryptoServiceProvider();
int i = cryptoProvider.KeySize;
MemoryStream ms = new MemoryStream();
CryptoStream cst = new
CryptoStream(ms, cryptoProvider.CreateEncryptor(byKey, byIV), CryptoStreamMode.Write);

StreamWriter sw = new StreamWriter(cst);
sw.Write(data);
sw.Flush();
cst.FlushFinalBlock();
sw.Flush();
return Convert.ToBase64String(ms.GetBuffer(), 0, (int)ms.Length);

}

public static string Decode(string data)
{
byte[] byKey = System.Text.ASCIIEncoding.ASCII.GetBytes(KEY_64);
byte[] byIV = System.Text.ASCIIEncoding.ASCII.GetBytes(IV_64);

byte[] byEnc;
try
{
byEnc = Convert.FromBase64String(data);
}
catch
{
return null;
}

DESCryptoServiceProvider cryptoProvider = new
DESCryptoServiceProvider();
MemoryStream ms = new MemoryStream(byEnc);
CryptoStream cst = new
CryptoStream(ms, cryptoProvider.CreateDecryptor(byKey, byIV), CryptoStreamMode.Read);
StreamReader sr = new StreamReader(cst);
return sr.ReadToEnd();
}
}
}