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java 对称加密算法实现详解

2019-11-26 08:46:30
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前言

对于信息的加密方式多种多样,之前为大家介绍了一种自己设计的加密方式,有兴趣的朋友可以欣赏一下,欢迎给予指点。今天为大家介绍一下对称加密方式,所谓对称加密指的是加密和解密方式呈对称格式,即解密是加密的逆过程,下面我们就看一下:DES、3DES、AES、PBE这四种方式,他们的加密强度依次递增。好吧闲话少说,上代码:

首先我们先看一下DES:

package cn.edu.hpu.des;import java.security.Key;import javax.crypto.Cipher;import javax.crypto.KeyGenerator;import javax.crypto.SecretKey;import javax.crypto.SecretKeyFactory;import javax.crypto.spec.DESKeySpec;public class jdk_DES {  private static final String src = "I Love You !";  public static void main(String [] args){    jdk_DES.jdkDES();  }  @SuppressWarnings("static-access")  public static void jdkDES(){    try {      //获得KEY      KeyGenerator keyGenerator = KeyGenerator.getInstance("DES");      keyGenerator.init(56);//设置为默认值56即可      //获得KEY对象      SecretKey secrekeyone = keyGenerator.generateKey();      byte [] byteskey = secrekeyone.getEncoded();            //KEY转换      DESKeySpec deskeyspec = new DESKeySpec(byteskey);      SecretKeyFactory factory = SecretKeyFactory.getInstance("DES");      Key secerkeytwo = factory.generateSecret(deskeyspec);            //加密      Cipher cipher = Cipher.getInstance("DES/ECB/PKCS5Padding");      cipher.init(cipher.ENCRYPT_MODE, secerkeytwo);//设置模式为加密      byte[] result = cipher.doFinal(src.getBytes());      System.out.println("jdkEDS:"+result.toString());            //解密      cipher.init(cipher.DECRYPT_MODE, secerkeytwo);//设置模式为解密      result = cipher.doFinal(result);      System.out.println("jdkEDS:"+new String(result));          } catch (Exception e) {      e.printStackTrace();    }  }}

运行结果:

第二种3重DES:

package cn.edu.hpu.des;import java.security.Key;import java.security.SecureRandom;import javax.crypto.Cipher;import javax.crypto.KeyGenerator;import javax.crypto.SecretKey;import javax.crypto.SecretKeyFactory;import javax.crypto.spec.DESKeySpec;public class jdk_3DES {  private static final String src = "I Love You !";  public static void main(String [] args){    jdk_3DES.jdk3DES();  }  @SuppressWarnings("static-access")  public static void jdk3DES(){    try {      //获得KEY      KeyGenerator keyGenerator = KeyGenerator.getInstance("DESede");      //keyGenerator.init(112);//设置密钥长度,默认值为168,也可设置为112      keyGenerator.init(new SecureRandom());//设置为默认值      //获得KEY对象      SecretKey secrekeyone = keyGenerator.generateKey();      byte [] byteskey = secrekeyone.getEncoded();            //KEY转换      DESKeySpec deskeyspec = new DESKeySpec(byteskey);      SecretKeyFactory factory = SecretKeyFactory.getInstance("DES");      Key secerkeytwo = factory.generateSecret(deskeyspec);            //加密      Cipher cipher = Cipher.getInstance("DES/ECB/PKCS5Padding");      cipher.init(cipher.ENCRYPT_MODE, secerkeytwo);//设置模式为加密      byte[] result = cipher.doFinal(src.getBytes());      System.out.println("jdkEDS:"+result.toString());            //解密      cipher.init(cipher.DECRYPT_MODE, secerkeytwo);//设置模式为解密      result = cipher.doFinal(result);      System.out.println("jdkEDS:"+new String(result));          } catch (Exception e) {      e.printStackTrace();    }  }}

运行结果:

第三种AES:

package cn.edu.hpu.aes;import java.security.Key;import java.security.SecureRandom;import javax.crypto.Cipher;import javax.crypto.KeyGenerator;import javax.crypto.SecretKey;import javax.crypto.spec.SecretKeySpec;public class jdk_AES {  private static final String src = "I Love You !";  public static void main(String [] args){    AES();  }  public static void AES(){    try {      //获得key      KeyGenerator keyGenerator = KeyGenerator.getInstance("AES");      keyGenerator.init(new SecureRandom());//默认密钥长度为:      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("AES="+result.toString());            //解密      cipher.init(Cipher.DECRYPT_MODE, key);      result = cipher.doFinal(result);      System.out.println("AES="+new String(result));          } catch (Exception e) {      e.printStackTrace();    }    }}

运行结果:

最后一种PBE:

package cn.edu.hpu.pbe;import java.security.Key;import java.security.SecureRandom;import javax.crypto.Cipher;import javax.crypto.SecretKeyFactory;import javax.crypto.spec.PBEKeySpec;import javax.crypto.spec.PBEParameterSpec;public class jdk_PBE {  public static final String src = "I Love You !";  public static void main(String [] args){    jdkPBE();  }  private static void jdkPBE(){    try {      //初始化盐      SecureRandom random = new SecureRandom();      byte [] salt = random.generateSeed(8);            //口令和密钥      String password = "imooc";      PBEKeySpec pbeKeySpec = new PBEKeySpec(password.toCharArray());//生成密钥转换对象      SecretKeyFactory factory = SecretKeyFactory.getInstance("PBEWITHMD5andDES");      Key key = factory.generateSecret(pbeKeySpec);            //加密      PBEParameterSpec pbeParameterSpec = new PBEParameterSpec(salt, 100);//实例化PBE对象的一个输入的材料:参数分别为"盐和迭代次数"      Cipher cipher = Cipher.getInstance("PBEWITHMD5andDES");      cipher.init(Cipher.ENCRYPT_MODE, key, pbeParameterSpec);      byte [] result = cipher.doFinal(src.getBytes());      System.out.println("PBE:"+result.toString());            //解密      cipher.init(Cipher.DECRYPT_MODE, key, pbeParameterSpec);      result = cipher.doFinal(result);      System.out.println("PBE:"+new String(result));          } catch (Exception e) {      e.printStackTrace();    }  }}

运行结果:

结语

对于以上四种方式,PBE是一种较安全的加密方式,对加密起绝定作用的是盐和password,决定着加密的结果。以上即使要为大家介绍的对称加密方式,哪位有更好的方式,还望指教。

以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持武林网。

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