C# DES

using System;

//这个是使用DES的基础

using System.Security.Cryptography;

//这个是处理文字编码的前提

using System.Text;

//以“流”的形式处理文字，也是微软DES算法要求的

using System.IO;

/// <summary>

/// DES加密方法

/// </summary>

/// <param name="strPlain">明文</param>

/// <param name="strDESKey">密钥</param>

/// <param name="strDESIV">向量</param>

/// <returns>密文</returns>

public string DESEncrypt(string strPlain,string strDESKey,string strDESIV)

{

//把密钥转换成字节数组

byte[] bytesDESKey=ASCIIEncoding.ASCII.GetBytes(strDESKey);

//把向量转换成字节数组

byte[] bytesDESIV=ASCIIEncoding.ASCII.GetBytes(strDESIV);

//声明1个新的DES对象

DESCryptoServiceProvider desEncrypt=new DESCryptoServiceProvider();

//开辟一块内存流

MemoryStream msEncrypt=new MemoryStream();

//把内存流对象包装成加密流对象

CryptoStream csEncrypt=new CryptoStream(msEncrypt,desEncrypt.CreateEncryptor(bytesDESKey,bytesDESIV),CryptoStreamMode.Write);

//把加密流对象包装成写入流对象

StreamWriter swEncrypt=new StreamWriter(csEncrypt);

//写入流对象写入明文

swEncrypt.WriteLine(strPlain);

//写入流关闭

swEncrypt.Close();

//加密流关闭

csEncrypt.Close();

//把内存流转换成字节数组，内存流现在已经是密文了

byte[] bytesCipher=msEncrypt.ToArray();

//内存流关闭

msEncrypt.Close();

//把密文字节数组转换为字符串，并返回

return UnicodeEncoding.Unicode.GetString(bytesCipher);

}

/// <summary>

/// DES解密方法

/// </summary>

/// <param name="strCipher">密文</param>

/// <param name="strDESKey">密钥</param>

/// <param name="strDESIV">向量</param>

/// <returns>明文</returns>

public string DESDecrypt(string strCipher,string strDESKey,string strDESIV)

{

//把密钥转换成字节数组

byte[] bytesDESKey=ASCIIEncoding.ASCII.GetBytes(strDESKey);

//把向量转换成字节数组

byte[] bytesDESIV=ASCIIEncoding.ASCII.GetBytes(strDESIV);

//把密文转换成字节数组

byte[] bytesCipher=UnicodeEncoding.Unicode.GetBytes(strCipher);

//声明1个新的DES对象

DESCryptoServiceProvider desDecrypt=new DESCryptoServiceProvider();

//开辟一块内存流，并存放密文字节数组

MemoryStream msDecrypt=new MemoryStream(bytesCipher);

//把内存流对象包装成解密流对象

CryptoStream csDecrypt=new CryptoStream(msDecrypt,desDecrypt.CreateDecryptor(bytesDESKey,bytesDESIV),CryptoStreamMode.Read);

//把解密流对象包装成读出流对象

StreamReader srDecrypt=new StreamReader(csDecrypt);

//明文=读出流的读出内容

string strPlainText=srDecrypt.ReadLine();

//读出流关闭

srDecrypt.Close();

//解密流关闭

csDecrypt.Close();

//内存流关闭

msDecrypt.Close();

//返回明文

return strPlainText;

}