DES-JAVA加密

/*des java 

complied ok with eclipse

 先建立一個DesEncrypt 類，然後把下面的代碼複製上去，編譯即可

*/
import java.security.Key;
import java.security.SecureRandom;
import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;

import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;

/**
*
* 使用DES加密與解密,可對byte[],String類型進行加密與解密
* 密文可使用String,byte[]儲存.
*
* 方法:
* void getKey(String strKey)從strKey的字條產生一個Key
*
* String getEncString(String strMing)對strMing進行加密,返回String密文
* String getDesString(String strMi)對strMin進行解密,返回String明文
*
*byte[] getEncCode(byte[] byteS)byte[]型的加密
*byte[] getDesCode(byte[] byteD)byte[]型的解密
*/

public class DesEncrypt
{
Key key;

/**
* 根據參數產生KEY
* @param strKey
*/
public void getKey(String strKey)
{
try{
KeyGenerator _generator = KeyGenerator.getInstance("DES");
_generator.init(new SecureRandom(strKey.getBytes()));
this.key = _generator.generateKey();
_generator=null;
}catch(Exception e){
e.printStackTrace();
}
}
/**
* 加密String明文輸入,String密文輸出
* @param strMing
* @return
*/
public String getEncString(String strMing)
{
byte[] byteMi = null;
byte[] byteMing = null;
String strMi = "";
BASE64Encoder base64en = new BASE64Encoder();
try
{
byteMing = strMing.getBytes("UTF8");
byteMi = this.getEncCode(byteMing);
strMi = base64en.encode(byteMi);
}
catch(Exception e)
{
e.printStackTrace();
}
finally
{
base64en = null;
byteMing = null;
byteMi = null;
}
return strMi;
}
/**
* 解密 以String密文輸入,String明文輸出
* @param strMi
* @return
*/
public String getDesString(String strMi)
{
BASE64Decoder base64De = new BASE64Decoder();
byte[] byteMing = null;
byte[] byteMi = null;
String strMing = "";
try
{
byteMi = base64De.decodeBuffer(strMi);
byteMing = this.getDesCode(byteMi);
strMing = new String(byteMing, "UTF8");
}
catch(Exception e)
{
e.printStackTrace();
}
finally
{
base64De = null;
byteMing = null;
byteMi = null;
}
return strMing;
}
/**
* 加密以byte[]明文輸入,byte[]密文輸出
* @param byteS
* @return
*/
private byte[] getEncCode(byte[] byteS)
{
byte[] byteFina = null;
Cipher cipher;
try
{
cipher = Cipher.getInstance("DES");
cipher.init(Cipher.ENCRYPT_MODE, key);
byteFina = cipher.doFinal(byteS);
}
catch(Exception e)
{
e.printStackTrace();
}
finally
{
cipher = null;
}
return byteFina;
}
/**
* 解密以byte[]密文輸入,以byte[]明文輸出
* @param byteD
* @return
*/
private byte[] getDesCode(byte[] byteD)
{
Cipher cipher;
byte[] byteFina=null;
try{
cipher = Cipher.getInstance("DES");
cipher.init(Cipher.DECRYPT_MODE, key);
byteFina = cipher.doFinal(byteD);
}catch(Exception e){
e.printStackTrace();
}finally{
cipher=null;
}
return byteFina;

}

public static void main(String[] args){

System.out.println("des demo");
DesEncrypt des=new DesEncrypt();//執行個體化一個對像
des.getKey("MYKEY11");//產生密匙
System.out.println("key=MYKEY11");
String strEnc = des.getEncString("CHINA");//加密字串,返回String的密文
System.out.println("密文="+strEnc);

String strDes = des.getDesString(strEnc);//把String 類型的密文解密
System.out.println("明文="+strDes);

}

}

/*

運行結果：

des demo
key=MYKEY11
密文=n2r7F/mmYiY=
明文=CHINA

*/

本文來自CSDN部落格，轉載請標明出處：http://blog.csdn.net/chinayaosir/archive/2008/10/20/3111507.aspx