import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;
import javax.crypto.spec.IvParameterSpec;

public class Des {
private byte[] desKey;

//解密數據
public static String decrypt(String message,String key) throws Exception {

byte[] bytesrc =convertHexString(message);
Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");
DESKeySpec desKeySpec = new DESKeySpec(key.getBytes("UTF-8"));
SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
SecretKey secretKey = keyFactory.generateSecret(desKeySpec);
IvParameterSpec iv = new IvParameterSpec(key.getBytes("UTF-8"));

cipher.init(Cipher.DECRYPT_MODE, secretKey, iv);

byte[] retByte = cipher.doFinal(bytesrc);
return new String(retByte);
}

public static byte[] encrypt(String message, String key)
throws Exception {
Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");

DESKeySpec desKeySpec = new DESKeySpec(key.getBytes("UTF-8"));

SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
SecretKey secretKey = keyFactory.generateSecret(desKeySpec);
IvParameterSpec iv = new IvParameterSpec(key.getBytes("UTF-8"));
cipher.init(Cipher.ENCRYPT_MODE, secretKey, iv);

return cipher.doFinal(message.getBytes("UTF-8"));
}

public static byte[] convertHexString(String ss)
{
byte digest[] = new byte[ss.length() / 2];
for(int i = 0; i < digest.length; i++)
{
String byteString = ss.substring(2 * i, 2 * i + 2);
int byteValue = Integer.parseInt(byteString, 16);
digest[i] = (byte)byteValue;
}

return digest;
}

public static void main(String[] args) throws Exception {
String key = "12345678";
String value="test1234 ";
String jiami=java.net.URLEncoder.encode(value, "utf-8").toLowerCase();

System.out.println("加密數據:"+jiami);
String a=toHexString(encrypt(jiami, key)).toUpperCase();

System.out.println("加密后的數據為:"+a);
String b=java.net.URLDecoder.decode(decrypt(a,key), "utf-8") ;
System.out.println("解密后的數據:"+b);

}

public static String toHexString(byte b[]) {
StringBuffer hexString = new StringBuffer();
for (int i = 0; i < b.length; i++) {
String plainText = Integer.toHexString(0xff & b[i]);
if (plainText.length() < 2)
plainText = "0" + plainText;
hexString.append(plainText);
}

return hexString.toString();
}

}

using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Data.SqlClient;
using System.Security.Cryptography;
using System.IO;
using System.Text;
public class TestDes{
//cookies加密密鑰
public static string DES_Key = "12345678";

#region DESEnCode DES加密
public static string DESEnCode(string pToEncrypt, string sKey)
{
pToEncrypt = HttpContext.Current.Server.UrlEncode(pToEncrypt);
DESCryptoServiceProvider des = new DESCryptoServiceProvider();
byte[] inputByteArray = Encoding.GetEncoding("UTF-8").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();

StringBuilder ret = new StringBuilder();
foreach (byte b in ms.ToArray())
{
ret.AppendFormat("{0:X2}", b);
}
ret.ToString();
return ret.ToString();
}
#endregion

#region DESDeCode DES解密
public static string DESDeCode(string pToDecrypt, string sKey)
{
// HttpContext.Current.Response.Write(pToDecrypt + "<br>" + sKey);
// HttpContext.Current.Response.End();
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);
MemoryStream ms = new MemoryStream();
CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(), CryptoStreamMode.Write);
cs.Write(inputByteArray, 0, inputByteArray.Length);
cs.FlushFinalBlock();

StringBuilder ret = new StringBuilder();

return HttpContext.Current.Server.UrlDecode(System.Text.Encoding.Default.GetString(ms.ToArray()));
}
#endregion

public TestDes()
{
//
// TODO: 在此處添加構造函數邏輯
//
}
}