C# DES

 

using System;
//這個是使用DES的基礎
using System.Security.Cryptography;
//這個是處理文字編碼的前提
using System.Text;
//以“流”的形式處理文字，也是微軟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">密鑰</param>
/// <param name="strDESIV">向量</param>
/// <returns>密文</returns>
public string DESEncrypt(string strPlain,string strDESKey,string strDESIV)
{
//把密鑰轉換成字節數組
byte[] bytesDESKey=ASCIIEncoding.ASCII.GetBytes(strDESKey);
//把向量轉換成字節數組
byte[] bytesDESIV=ASCIIEncoding.ASCII.GetBytes(strDESIV);
//聲明1個新的DES對象
DESCryptoServiceProvider desEncrypt=new DESCryptoServiceProvider();
//開闢一塊內存流
MemoryStream msEncrypt=new MemoryStream();
//把內存流對象包裝成加密流對象
CryptoStream csEncrypt=new CryptoStream(msEncrypt,desEncrypt.CreateEncryptor(bytesDESKey,bytesDESIV),CryptoStreamMode.Write);
//把加密流對象包裝成寫入流對象
StreamWriter swEncrypt=new StreamWriter(csEncrypt);
//寫入流對象寫入明文
swEncrypt.WriteLine(strPlain);
//寫入流關閉
swEncrypt.Close();
//加密流關閉
csEncrypt.Close();
//把內存流轉換成字節數組，內存流現在已經是密文了
byte[] bytesCipher=msEncrypt.ToArray();
//內存流關閉
msEncrypt.Close();
//把密文字節數組轉換爲字符串，並返回
return UnicodeEncoding.Unicode.GetString(bytesCipher);
}
/// <summary>
/// DES解密方法
/// </summary>
/// <param name="strCipher">密文</param>
/// <param name="strDESKey">密鑰</param>
/// <param name="strDESIV">向量</param>
/// <returns>明文</returns>
public string DESDecrypt(string strCipher,string strDESKey,string strDESIV)
{
//把密鑰轉換成字節數組
byte[] bytesDESKey=ASCIIEncoding.ASCII.GetBytes(strDESKey);
//把向量轉換成字節數組
byte[] bytesDESIV=ASCIIEncoding.ASCII.GetBytes(strDESIV);
//把密文轉換成字節數組
byte[] bytesCipher=UnicodeEncoding.Unicode.GetBytes(strCipher);
//聲明1個新的DES對象
DESCryptoServiceProvider desDecrypt=new DESCryptoServiceProvider();
//開闢一塊內存流，並存放密文字節數組
MemoryStream msDecrypt=new MemoryStream(bytesCipher);
//把內存流對象包裝成解密流對象
CryptoStream csDecrypt=new CryptoStream(msDecrypt,desDecrypt.CreateDecryptor(bytesDESKey,bytesDESIV),CryptoStreamMode.Read);
//把解密流對象包裝成讀出流對象
StreamReader srDecrypt=new StreamReader(csDecrypt);
//明文=讀出流的讀出內容
string strPlainText=srDecrypt.ReadLine();
//讀出流關閉
srDecrypt.Close();
//解密流關閉
csDecrypt.Close();
//內存流關閉
msDecrypt.Close();
//返回明文
return strPlainText;
}