DES的JAVA实现方法

/*
* 当前文件：DesEncrypt.java
* 创建日期：2005-7-29
* 版 本 号：1.0
* 作者：kang1
*
*/

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加密与解密,可对byte[],String类型进行加密与解密
* 密文可使用String,byte[]存储.
*
* 方法:
* void getKey(String strKey)从strKey的字条生成一个Key
*
* String getEncString(String strMing)对strMing进行加密,返回String密文
* String getDesString(String strMi)对strMin进行解密,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;

/**
* 根据参数生成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明文输入,String密文输出
* @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密文输入,String明文输出
* @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[]明文输入,byte[]密文输出
* @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[]密文输入,以byte[]明文输出
* @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("hello");
DesEncrypt des=new DesEncrypt();//实例化一个对像
des.getKey("aadd");//生成密匙

String strEnc = des.getEncString("钟汉康");//加密字符串,返回String的密文
System.out.println(strEnc);

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

}

}

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import java.security.SecureRandom;

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

public class Encrypt {

public Encrypt() {
}

public byte[] getKey() throws Exception {
return "[B@170888e".getBytes();
}

public byte[] encryptData(String encryptdata)
throws Exception {
SecureRandom sr = new SecureRandom();
byte[] rawKeyData = getKey();

DESKeySpec dks = new DESKeySpec(rawKeyData);

SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
SecretKey key = keyFactory.generateSecret(dks);
Cipher cipher = Cipher.getInstance("DES");
cipher.init(Cipher.ENCRYPT_MODE, key, sr);
byte[] data = encryptdata.getBytes();
byte[] encryptedData = cipher.doFinal(data);

return encryptedData;
}

public String decryptData(byte[] decryptdata)
throws Exception {

SecureRandom sr = new SecureRandom();

byte[] rawKeyData = getKey();
DESKeySpec dks = new DESKeySpec(rawKeyData);

SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
SecretKey key = keyFactory.generateSecret(dks);

Cipher cipher = Cipher.getInstance("DES");
cipher.init(Cipher.DECRYPT_MODE, key, sr);

byte[] encryptedData = decryptdata;
byte[] decryptedData = cipher.doFinal(encryptedData);
return new String(decryptedData);
}

public static void main(String[] args) {
try {
Encrypt encrypt = new Encrypt();
String enpasswd = encrypt.encryptData("111111");
String depasswd = encrypt.decryptData( enpasswd );

} catch (Exception e) {
e.printStackTrace();
}
}
}