对称加密算法，就是公钥和私钥是一样的。这里主要有DES、3重DES、AES和PBE等，以下为各个对称加密算法的加解密使用方法，所有的类均引自JDK,无需另外导包（视情况可能需要阿帕奇的commons.codec包）。

其中AES为目前使用最多的，因为安全性上从未被破解过。

PBE是基于口令的加密，使用中要加入salt(盐--扰码)进行使用。

1、DES

import org.apache.commons.codec.binary.Hex;


import javax.crypto.Cipher;

import javax.crypto.KeyGenerator;

import javax.crypto.SecretKey;

import javax.crypto.SecretKeyFactory;

import javax.crypto.spec.DESKeySpec;

import java.security.Key;


/**

* @Author Rhine

* @Date 2019/1/17 20:19

**/

public class ImoocDES {


private static String src="imooc security des";


public static void main(String[] args) {

jdkAES();

}


public static void jdkAES(){

try {

//生成key

KeyGenerator keyGenerator=KeyGenerator.getInstance("DES");

keyGenerator.init(56);

SecretKey secretKey=keyGenerator.generateKey();

byte[] byteKey=secretKey.getEncoded();


//key转化

DESKeySpec desKeySpec=new DESKeySpec(byteKey);

SecretKeyFactory factory=SecretKeyFactory.getInstance("DES");

Key convertSecretKey=factory.generateSecret(desKeySpec);


//加密

Cipher cipher=Cipher.getInstance("DES/ECB/PKCS5Padding");

cipher.init(Cipher.ENCRYPT_MODE,convertSecretKey);


byte[] result=cipher.doFinal(src.getBytes());

System.out.println("jdk des encrypt: "+ Hex.encodeHexString(result));


//解密

cipher.init(Cipher.DECRYPT_MODE,convertSecretKey);

result=cipher.doFinal(result);

System.out.println("jdk des decrypt: "+ new String(result));


}catch (Exception e){


}

}

}

2、3重DES

import org.apache.commons.codec.binary.Hex;


import javax.crypto.Cipher;

import javax.crypto.KeyGenerator;

import javax.crypto.SecretKey;

import javax.crypto.SecretKeyFactory;

import javax.crypto.spec.DESedeKeySpec;

import java.security.Key;


/**

* @Author Rhine

* @Date 2019/1/17 20:08

**/

public class Imooc3DES {


private static String src="imooc security 3des";


public static void main(String[] args) {

jdk3DES();

}


public static void jdk3DES(){

try {

//生成key

KeyGenerator keyGenerator=KeyGenerator.getInstance("DESede");

keyGenerator.init(168);

SecretKey secretKey=keyGenerator.generateKey();

byte[] byteKey=secretKey.getEncoded();


//key转化

DESedeKeySpec deSedeKeySpec=new DESedeKeySpec(byteKey);

SecretKeyFactory factory=SecretKeyFactory.getInstance("DESede");

Key convertSecretKey=factory.generateSecret(deSedeKeySpec);


//加密

Cipher cipher=Cipher.getInstance("DESede/ECB/PKCS5Padding");

cipher.init(Cipher.ENCRYPT_MODE,convertSecretKey);

byte[] result=cipher.doFinal(src.getBytes());

System.out.println("jdk 3des encrypt: "+ Hex.encodeHexString(result));


//解密

cipher.init(Cipher.DECRYPT_MODE,convertSecretKey);

result=cipher.doFinal(result);

System.out.println("jdk 3des decrypt: "+ new String(result));

}catch (Exception e){

e.printStackTrace();

}

}

}

3、AES（目前使用最多的，未被破解过）

import org.apache.commons.codec.binary.Base64;


import javax.crypto.Cipher;

import javax.crypto.KeyGenerator;

import javax.crypto.SecretKey;

import javax.crypto.spec.SecretKeySpec;

import java.security.Key;


/**

* @Author Rhine

* @Date 2019/1/17 20:19

**/

public class ImoocAES {


private static String src="imooc security aes";


public static void main(String[] args) {

jdkAES();

}


public static void jdkAES(){

try {

//生成key

KeyGenerator keyGenerator=KeyGenerator.getInstance("AES");

keyGenerator.init(128);

SecretKey secretKey=keyGenerator.generateKey();

byte[] keyBytes=secretKey.getEncoded();


//key转化

Key key=new SecretKeySpec(keyBytes,"AES");


//加密

Cipher cipher=Cipher.getInstance("AES/ECB/PKCS5Padding");

cipher.init(Cipher.ENCRYPT_MODE,key);


byte[] result=cipher.doFinal(src.getBytes());

System.out.println("jdk aes encrypt: "+ Base64.encodeBase64String(result));


//解密

cipher.init(Cipher.DECRYPT_MODE,key);

result=cipher.doFinal(result);

System.out.println("jdk aes decrypt: "+ new String(result));


}catch (Exception e){


}

}

}

4、PBE

import org.apache.commons.codec.binary.Base64;


import javax.crypto.Cipher;

import javax.crypto.SecretKeyFactory;

import javax.crypto.spec.PBEKeySpec;

import javax.crypto.spec.PBEParameterSpec;

import java.security.Key;

import java.security.SecureRandom;


/**

* @Author Rhine

* @Date 2019/1/17 23:17

**/

public class ImoocPBE {


private static String src="imooc security pbe";


public static void main(String[] args) {

jdkPBE();

}


public static void jdkPBE(){

try {

//初始化盐

SecureRandom random=new SecureRandom();

byte[] salt=random.generateSeed(8);


//口令与密钥

String password="imooc";

PBEKeySpec pbeKeySpec=new PBEKeySpec(password.toCharArray());

SecretKeyFactory factory=SecretKeyFactory.getInstance("PBEWITHMD5andDES");

Key key=factory.generateSecret(pbeKeySpec);


//加密

PBEParameterSpec pbeParameterSpec=new PBEParameterSpec(salt,100);

Cipher cipher=Cipher.getInstance("PBEWITHMD5andDES");

cipher.init(Cipher.ENCRYPT_MODE,key,pbeParameterSpec);

byte[] result = cipher.doFinal(src.getBytes());

System.out.println("jdk pbe encrypt: "+Base64.encodeBase64String(result));


//解密

cipher.init(Cipher.DECRYPT_MODE,key,pbeParameterSpec);

result=cipher.doFinal(result);

System.out.println("jdk pbe decrypt: "+new String(result));


}catch (Exception e){

e.printStackTrace();

}

}

}