时间:2017年4月11日星期二
说明:本文部分内容均来自慕课网。@慕课网:http://www.imooc.com
教学示例源码:https://github.com/zccodere/s...
个人学习源码:https://github.com/zccodere/s...
第一章:对称加密算法DES
1-1 JAVA对称加密算法DES
加密密钥=解密密钥
对称加密算法
初等
DES--3DES
AES
PBE
IDEA
算法实现:
代码演示:
package com.myimooc.security.des;import org.apache.commons.codec.binary.Hex;
import org.bouncycastle.jce.provider.BouncyCastleProvider;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;
import java.security.NoSuchAlgorithmException;
import java.security.Security;/*** DES对称加密演示* Created by ZC on 2017/4/11.*/
public class DemoDES {/** 待加密字符串 */private static String src="imooc security des";public static void main(String[] args){jdkDES();bcDES();}/** 使用 jdk 实现des加解密 */public static void jdkDES(){try {// 生成KEYKeyGenerator keyGenerator = KeyGenerator.getInstance("DES");keyGenerator.init(56);SecretKey secretKey = keyGenerator.generateKey();byte[] byteKey = secretKey.getEncoded();// KEY转换DESKeySpec desKeySpec = new DESKeySpec(byteKey);SecretKeyFactory secretKeyFactory = SecretKeyFactory.getInstance("DES");Key convertSecretKey = secretKeyFactory.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) {e.printStackTrace();}}/** 使用BouncyCastle实现DES加解密 */public static void bcDES(){try {Security.addProvider(new BouncyCastleProvider());// 生成KEYKeyGenerator keyGenerator = KeyGenerator.getInstance("DES","BC");keyGenerator.init(56);SecretKey secretKey = keyGenerator.generateKey();byte[] byteKey = secretKey.getEncoded();// KEY转换DESKeySpec desKeySpec = new DESKeySpec(byteKey);SecretKeyFactory secretKeyFactory = SecretKeyFactory.getInstance("DES");Key convertSecretKey = secretKeyFactory.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) {e.printStackTrace();}}
}
流程演示:
第二章:对称加密算法3DES
2-1 JAVA对称加密算法3DES
为什么会有3重DES,DES的劣势
1.违反柯克霍夫原则
2.安全问题
3重DES的好处
1.密钥长度增强
2.迭代次数提高
算法实现:
代码演示:
package com.myimooc.security.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 javax.crypto.spec.DESedeKeySpec;
import java.security.Key;
import java.security.SecureRandom;/*** 3DES对称加密演示* Created by ZC on 2017/4/11.*/
public class Demo3DES {/** 待加密字符串 */private static String src="imooc security 3des";public static void main(String[] args){jdk3des();}/** 使用jdk实现3重DES加解密 */private static void jdk3des(){try {// 生成KEYKeyGenerator keyGenerator = KeyGenerator.getInstance("DESede");//keyGenerator.init(168);keyGenerator.init(new SecureRandom());SecretKey secretKey = keyGenerator.generateKey();byte[] byteKey = secretKey.getEncoded();// KEY转换DESedeKeySpec desKeySpec = new DESedeKeySpec(byteKey);SecretKeyFactory secretKeyFactory = SecretKeyFactory.getInstance("DESede");Key convertSecretKey = secretKeyFactory.generateSecret(desKeySpec);// 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();}}
}
第三章:对称加密算法AES
3-1 JAVA对称加密算法AES
JAVA对称加密算法:AES
AES是目前使用最多的对称加密算法
AES的优势之一是至今尚未被破解
AES通常用于移动通信系统加密以及基于SSH协议的软件比如:SSH Clint、secureCRT
AES算法
高级
DES替代者
算法实现:
代码演示:
package com.myimooc.security.aes;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;
import java.security.NoSuchAlgorithmException;/*** /*** AES对称加密演示* Created by ZC on 2017/4/11.*/
public class DemoAES {/** 待加密字符串 */private static String src="imooc security aes";public static void main(String[] args){jdkAES();}/** 通过JDK实现AES对称加密 */public static void jdkAES(){try {// 生成KEYKeyGenerator keyGenerator = KeyGenerator.getInstance("AES");keyGenerator.init(128);SecretKey secretKey = keyGenerator.generateKey();byte[] keyBytes = secretKey.getEncoded();// KEY 转换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) {e.printStackTrace();}}
}
流程演示:
第四章:对称加密算法PBE
4-1 JAVA对称加密算法PBE
PBE:综合性对称加密算法
PBE(Password Based Encyption)基于口令加密
对已有算法的包装
JDK、BC
盐
PBEWithMD5AndDES
算法实现:
代码演示:
package com.myimooc.security.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;/*** /*** /*** PBE对称加密演示* Created by ZC on 2017/4/11.*/
public class DemoPBE {/** 待加密字符串 */private static String src="imooc security pbe";private static final String TOKEN = "imooc";public static void main(String[] args){jdkPBE();}/** 使用JDK实现PBE算法加解密 */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 = TOKEN;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:"+ Base64.encodeBase64String(result));}catch (Exception e){e.printStackTrace();}}
}
流程演示:
第五章:小结
5-1 对称加密算法小结
对称加密算法:回顾
初等
DES--3DES
AES
PBE
加密和解密不在同一方怎么办?
把密钥发给对方