2018-2019-2 20175105王鑫浩 实验五《网络编程与安全》实验报告

一、实验报告封面

  • 课程:Java程序设计 班级:1751 班 姓名:王鑫浩 学号:20175105

  • 指导教师:娄嘉鹏

  • 实验日期:2019年5月29日

  • 实验序号:实验五

  • 实验名称:网络编程与安全


二、实验内容

检查点一:

两人一组结对编程:
0. 参考http://www.cnblogs.com/rocedu/p/6766748.html#SECDSA

  1. 结对实现中缀表达式转后缀表达式的功能 MyBC.java
  2. 结对实现从上面功能中获取的表达式中实现后缀表达式求值的功能,调用MyDC.java
  3. 上传测试代码运行结果截图和码云链接

编程思路:

由中缀式求得后缀式可以使用栈,伪代码如下:

  • 设立一个栈,存放运算符,首先栈为空;

  • 从左到右扫描中缀式,若遇到操作数,直接输出,并输出一个空格作为两个操作数的分隔符;

  • 若遇到运算符,则与栈顶比较,比栈顶级别高则进栈,否则退出栈顶元素并输出,然后输出一个空格作分隔符;

  • 若遇到左括号,进栈;若遇到右括号,则一直退栈输出,直到退到左括号止。

  • 当栈变成空时,输出的结果即为后缀表达式。

算符优先法求解表达式:

  • 步骤1:建立符号运算的优先级关系表

  • 步骤2 :

** (1) 设操作数栈OPND,置空;运算符栈OPTR,最低符号#压进OPTR;

** (2) 读入字符C,C若是操作数, 进OPND;若是运算符,与OPTR栈顶元素(A)比较,根据算符优先级,决定如何处理:

*** A<C, C压入OPTR栈;

*** A=C, A从OPTR出栈;

*** A>C,A出栈,从OPND依次弹出两个操作数y、x, 计算Z=x A y,Z压入OPND栈。C压进OPTR.
(3) 重复(2),直至表达式结束。

实验代码

MyBC.java

import java.util.Stack;
 
public class MyBC {
    static Stack<Character> op = new Stack<>();
    public static String getrp(String s){
        char[] arr = s.toCharArray();
        int len = arr.length;
        String out = "";
        for(int i =0;i<len;i++){
            char ch = arr[i];
            if(ch == ' ') continue;
            if(ch>='0'&&ch<='9'){
                out +=ch;
                continue;
            }
            if(ch =='(') op.push(ch);
            if(ch == '+'|| ch=='-'){
                while(!op.empty()&&(op.peek()!='('))
                    out +=op.pop();
                op.push(ch);
                continue;
            }
            if(ch=='*'||ch=='/'){
                while(!op.empty()&&(op.peek()=='*'||op.peek()=='/'))
                    out+=op.pop();
                op.push(ch);
                continue;
            }
            if(ch == ')'){
                while(!op.empty()&&op.peek()!='(')
                    out += op.pop();
                op.pop();
                continue;
            }
        }
        while(!op.empty()) out += op.pop();
        return out;
    }
}

MyDC.java

import java.util.Stack;
 
public class MyDC {
    static Stack<Character> op = new Stack<>();
 
    public static Float getv(char op, Float f1, Float f2) {
        if (op == '+') {
            return f2 + f1;
        } else if (op == '-') {
            return f2 - f1;
        } else if (op == '*') {
            return f2 * f1;
        } else if (op == '/') {
            return f2 / f1;
        } else {
            return Float.valueOf(-0);
        }
    }
 
    public static float calrp(String rp) {
        Stack<Float> v = new Stack<>();
        char[] arr = rp.toCharArray();
        int len = arr.length;
        for (int i = 0; i < len; i++) {
            Character ch = arr[i];
            if (ch >= '0' && ch <= '9') {
                v.push(Float.valueOf(ch - '0'));
            } else {
                v.push(getv(ch, v.pop(), v.pop()));
            }
        }
        return v.pop();
    }
}

Main.java

import java.util.Scanner;
public class Main {
    public static void main(String[] args){
        Scanner in = new Scanner(System.in);
        System.out.println("请输入运算式:");
        String s = in.nextLine();
        String s2 = MyBC.getrp(s);
        System.out.println("转换为后缀表达式:"+s2);
        System.out.println(MyDC.calrp(s2));
    }
}

运行效果

检查点二:

结对编程:
1人负责客户端,一人负责服务器
0. 注意责任归宿,要会通过测试证明自己没有问题

  1. 基于Java Socket实现客户端/服务器功能,传输方式用TCP
  2. 客户端让用户输入中缀表达式,然后把中缀表达式调用MyBC.java的功能转化为后缀表达式,把后缀表达式通过网络发送给服务器
  3. 服务器接收到后缀表达式,调用MyDC.java的功能计算后缀表达式的值,把结果发送给客户端
  4. 客户端显示服务器发送过来的结果
  5. 上传测试结果截图和码云链接

编写思路

1.利用教材上学到的知识编写服务器端与客户端链接代码
2.通过服务器端与客户端调用MyDC与MyBC

编写代码

Client.java

import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
import java.io.*;
import java.security.Key;
import java.util.Scanner;
import java.net.*;
 
public class Client {
    // 搭建客户端
    public static void main(String[] args) throws IOException {
        try {
            // 1、创建客户端Socket,指定服务器地址和端口
 
            //下面是你要传输到另一台电脑的IP地址和端口
            Socket socket = new Socket("192.168.56.1", 5209);
            System.out.println("客户端启动成功");
            // 2、获取输出流,向服务器端发送信息
            // 向本机的52000端口发出客户请求
 
            BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
            // 由系统标准输入设备构造BufferedReader对象
            PrintWriter write = new PrintWriter(socket.getOutputStream());
            // 由Socket对象得到输出流,并构造PrintWriter对象
            //3、获取输入流,并读取服务器端的响应信息 
            BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
            // 由Socket对象得到输入流,并构造相应的BufferedReader对象
            String readline;
            readline = br.readLine(); // 从系统标准输入读入一字符串
            readline = MyBC.getrp(readline);
 
 
            while (!readline.equals("end")) {
                // 若从标准输入读入的字符串为 "end"则停止循环
                write.println(readline);
                // 将从系统标准输入读入的字符串输出到Server
                write.flush();
                // 刷新输出流,使Server马上收到该字符串
                System.out.println("客户:" + readline);
                // 在系统标准输出上打印读入的字符串
                System.out.println("服务:" + in.readLine());
                // 从Server读入一字符串,并打印到标准输出上
                readline = br.readLine(); // 从系统标准输入读入一字符串
            } // 继续循环
            //4、关闭资源 
            write.close(); // 关闭Socket输出流
            in.close(); // 关闭Socket输入流
            socket.close(); // 关闭Socket
        } catch (Exception e) {
            System.out.println("can not listen to:" + e);// 出错,打印出错信息
        }
    }
 
}

Service.java

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
 
public class Service {
    //搭建服务器端
    public static void main(String[] args) throws IOException{
        Service socketService = new Service();
        //1、a)创建一个服务器端,即Service 
        socketService.oneServer();
    }
    public  void oneServer(){
        try{
            ServerSocket server=null;
            try{
                //下面是端口,端口可以和客户端代码里面的端口一样
                server=new ServerSocket(5209);
                //b)指定绑定的端口,并监听此端口。
                System.out.println("服务器启动成功");
                //创建一个ServerSocket在端口5209监听客户请求
            }catch(Exception e) {
                System.out.println("没有启动监听:"+e);
                //出错,打印出错信息
            }
            Socket socket=null;
            try{
                socket=server.accept();
                //2、调用accept()方法开始监听,等待客户端的连接 
                //使用accept()阻塞等待客户请求,有客户
                //请求到来则产生一个Socket对象,并继续执行
            }catch(Exception e) {
                System.out.println("Error."+e);
                //出错,打印出错信息
            }
            //3、获取输入流,并读取客户端信息 
            String line;
            BufferedReader in=new BufferedReader(new InputStreamReader(socket.getInputStream()));
            //由Socket对象得到输入流,并构造相应的BufferedReader对象
            PrintWriter writer=new PrintWriter(socket.getOutputStream());
            //由Socket对象得到输出流,并构造PrintWriter对象
            BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
            //由系统标准输入设备构造BufferedReader对象
            Float m1=MyDC.calrp(in.readLine());
            System.out.println("Client:"+m1);
            //在标准输出上打印从客户端读入的字符串
            line = m1.toString();
            //从标准输入读入一字符串
            //4、获取输出流,响应客户端的请求 
            while(!line.equals("end")){
                //如果该字符串为 "bye",则停止循环
                writer.println(line);
                //向客户端输出该字符串
                writer.flush();
                //刷新输出流,使Client马上收到该字符串
                System.out.println("服务:"+line);
                //在系统标准输出上打印读入的字符串
                System.out.println("客户:"+in.readLine());
                //从Client读入一字符串,并打印到标准输出上
                line=br.readLine();
                //从系统标准输入读入一字符串
            } //继续循环
 
            //5、关闭资源 
            writer.close(); //关闭Socket输出流
            in.close(); //关闭Socket输入流
            socket.close(); //关闭Socket
            server.close(); //关闭ServerSocket
        }catch(Exception e) {//出错,打印出错信息
            System.out.println("Error."+e);
        }
    }
}

注:运行时先运行服务器端,再运行客户端,在客户端输入表达式。

运行效果


检查点三:

结对编程:1人负责客户端,一人负责服务器
0. 注意责任归宿,要会通过测试证明自己没有问题

  1. 基于Java Socket实现客户端/服务器功能,传输方式用TCP
  2. 客户端让用户输入中缀表达式,然后把中缀表达式调用MyBC.java的功能转化为后缀表达式,把后缀表达式用3DES或AES算法加密后通过网络把密文发送给服务器
  3. 服务器接收到后缀表达式表达式后,进行解密(和客户端协商密钥,可以用数组保存),然后调用MyDC.java的功能计算后缀表达式的值,把结果发送给客户端
  4. 客户端显示服务器发送过来的结果
  5. 上传测试结果截图和码云链接

编写思路

1.编写AES加密算法,先产生子密钥,然后调用java.security包

编写代码

Skey_AES.java

import java.io.*;
import javax.crypto.*;
public class Skey_AES{
    public static void main(String args[]) throws Exception{
        KeyGenerator kg=KeyGenerator.getInstance("AES");
        kg.init(128);
        SecretKey k=kg.generateKey( );
        FileOutputStream  f=new FileOutputStream("key1.dat");
        ObjectOutputStream b=new  ObjectOutputStream(f);
        b.writeObject(k);
    }
}

Encoder.java

import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import java.util.Base64;
import java.util.Scanner;
 
import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.KeyGenerator;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
 
import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;
 
public class Encoder {
    public static String AESEncode(String encodeRules,String content){
        try {
     
            KeyGenerator keygen=KeyGenerator.getInstance("AES");
      
            keygen.init(128, new SecureRandom(encodeRules.getBytes()));
      
            SecretKey original_key=keygen.generateKey();
    
            byte [] raw=original_key.getEncoded();
        
            SecretKey key=new SecretKeySpec(raw, "AES");
 
            Cipher cipher=Cipher.getInstance("AES");
 
            cipher.init(Cipher.ENCRYPT_MODE, key);
    
            byte [] byte_encode=content.getBytes("utf-8");
 
            byte [] byte_AES=cipher.doFinal(byte_encode);
       
            return AES_encode;
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        } catch (NoSuchPaddingException e) {
            e.printStackTrace();
        } catch (InvalidKeyException e) {
            e.printStackTrace();
        } catch (IllegalBlockSizeException e) {
            e.printStackTrace();
        } catch (BadPaddingException e) {
            e.printStackTrace();
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }
 
       
        return null;
    }
    
    public static String AESDncode(String encodeRules,String content){
        try {
            KeyGenerator keygen=KeyGenerator.getInstance("AES");
            keygen.init(128, new SecureRandom(encodeRules.getBytes()));
         
            SecretKey original_key=keygen.generateKey();
     
            byte [] raw=original_key.getEncoded();
           
            SecretKey key=new SecretKeySpec(raw, "AES");
      
            Cipher cipher=Cipher.getInstance("AES");
         
            cipher.init(Cipher.DECRYPT_MODE, key);
          
            byte [] byte_content= new BASE64Decoder().decodeBuffer(content);
          
            byte [] byte_decode=cipher.doFinal(byte_content);
            String AES_decode=new String(byte_decode,"utf-8");
            return AES_decode;
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        } catch (NoSuchPaddingException e) {
            e.printStackTrace();
        } catch (InvalidKeyException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } catch (IllegalBlockSizeException e) {
            e.printStackTrace();
        } catch (BadPaddingException e) {
            e.printStackTrace();
        }
        return null;
    }
 
}

Client.java

import java.io.*;
import java.net.*;
import java.lang.*;
import java.util.Scanner;
 
public class Client {
    public static void main(String args[]) throws Exception {
        String key = "";
        int n = -1;
        byte[] a = new byte[128];
        try {
            File f = new File("key1.dat");
            InputStream in = new FileInputStream(f);
            while ((n = in.read(a, 0, 100)) != -1) {
                key = key + new String(a, 0, n);
            }
            in.close();
        } catch (IOException e) {
            System.out.println("File read Error" + e);
        }
        Socket mysocket;
        DataInputStream in = null;
        DataOutputStream out = null;
        System.out.println("客户端连接成功:");
        Scanner scanner = new Scanner(System.in);
        String str = scanner.nextLine();//输入算式
        str = MyBC.getrp(str);
        String secret=Encoder.AESEncode(key,str);//客户端进行加密
        System.out.println("已加密:"+secret);
        try {
            mysocket = new Socket("127.1.0.0", 2010);
            in = new DataInputStream(mysocket.getInputStream());
            out = new DataOutputStream(mysocket.getOutputStream());
            out.writeUTF(key);
            out.writeUTF(secret);
            String s = in.readUTF();   //in读取信息,堵塞状态
            System.out.println("客户收到服务器的回答:" + s);
            Thread.sleep(500);
        } catch (Exception e) {
            System.out.println("服务器已断开" + e);
        }
    }
}

Server.java

import java.io.*;
import java.net.*;
public class Server {
    public static void main (String args[]) throws Exception {
        ServerSocket serverForClient=null;
        Socket socketOnServer=null;
        DataOutputStream out=null;
        DataInputStream  in=null;
        try { serverForClient = new ServerSocket(2010);
        }
        catch(IOException e1) {
            System.out.println(e1);
        }
        try{ System.out.println("等待客户呼叫");
            socketOnServer = serverForClient.accept(); //堵塞状态,除非有客户呼叫
            out=new DataOutputStream(socketOnServer.getOutputStream());
            in=new DataInputStream(socketOnServer.getInputStream());
            String key = in.readUTF();
            String s=in.readUTF(); // in读取信息,堵塞状态
            System.out.println("服务器收到的信息:"+s);
            String clear=Encoder.AESDncode(key,s);
            System.out.println("解密后:"+clear);
            float answer=MyDC.calrp(clear);
            out.writeUTF(answer+"");
            Thread.sleep(500);
        }
        catch(Exception e) {
            System.out.println("客户已断开"+e);
        }
    }
}

运行效果


检查点四:

结对编程:
1人负责客户端,一人负责服务器
0. 注意责任归宿,要会通过测试证明自己没有问题

  1. 基于Java Socket实现客户端/服务器功能,传输方式用TCP
  2. 客户端让用户输入中缀表达式,然后把中缀表达式调用MyBC.java的功能转化为后缀表达式,把后缀表达式用3DES或AES算法加密通过网络把密文发送给服务器
  3. 客户端和服务器用DH算法进行3DES或AES算法的密钥交换
  4. 服务器接收到后缀表达式表达式后,进行解密,然后调用MyDC.java的功能计算后缀表达式的值,把结果发送给客户端
  5. 客户端显示服务器发送过来的结果
  6. 上传测试结果截图和码云链接

编写代码

AtoB.java

public class AtoB {
    public static byte[] parseHexStr2Byte(String hexStr) {
        if (hexStr.length() < 1) {
            return null;
        }
        byte[] result = new byte[hexStr.length()/2];
        for (int i = 0;i< hexStr.length()/2; i++) {
            int high = Integer.parseInt(hexStr.substring(i*2, i*2+1), 16);
            int low = Integer.parseInt(hexStr.substring(i*2+1, i*2+2), 16);
            result[i] = (byte) (high * 16 + low);
        }
        return result;
    }
}

BtoA.java

public class BtoA {
    public static String parseByte2HexStr(byte buf[]) {
        StringBuffer sb = new StringBuffer();
        for (int i = 0; i < buf.length; i++) {
            String hex = Integer.toHexString(buf[i] & 0xFF);
            if (hex.length() == 1) {
                hex = '0' + hex;
            }
            sb.append(hex.toUpperCase());
        }
        return sb.toString();
    }
}

Agree.java

import javax.crypto.KeyAgreement;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
import java.io.*;
import java.security.PrivateKey;
import java.security.PublicKey;

public class Agree {
    public static SecretKeySpec createKey(String inpub,String inpri) throws Exception{
        String mode = "AES";
        //通过命令行参数传入公钥和私钥文件名,第一个命令行参数为对方的公钥文件名,第二个命令行参数为自己的私钥文件名。
        FileInputStream f1 = new FileInputStream(inpub);
        ObjectInputStream b1 = new ObjectInputStream(f1);
        PublicKey pbk = (PublicKey)b1.readObject();
        FileInputStream f2 = new FileInputStream(inpri);
        ObjectInputStream b2 = new ObjectInputStream(f2);
        PrivateKey prk = (PrivateKey) b2.readObject();
        KeyAgreement ka = KeyAgreement.getInstance("DH");
        ka.init(prk);
        ka.doPhase(pbk,true);

        byte[] s=ka.generateSecret();
        byte [] sb = new byte[24];
        for(int i=0;i<24;i++){
            sb[i]=s[i];
        }
        System.out.println("客户端与用户端的信息为:");
        for(int i=0;i<sb.length;i++){
            System.out.print(sb[i]+" ");
        }
        System.out.println();
        SecretKeySpec k=new  SecretKeySpec(sb,mode);

        return k;
    }
}

Client.java

import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
import java.io.*;
import java.security.Key;
import java.util.Scanner;
import java.net.*;
public class Client {
    public static void main(String[] args) {
        String mode = "AES";
        //客户端让用户输入中缀表达式,然后把中缀表达式调用MyBC.java的功能转化为后缀表达式,把后缀表达式通过网络发送给服务器
        Scanner scanner = new Scanner(System.in);
        Socket mysocket;
        DataInputStream in = null;
        DataOutputStream out = null;
        try {
            mysocket = new Socket("127.0.0.1", 2010);
            in = new DataInputStream(mysocket.getInputStream());
            out = new DataOutputStream(mysocket.getOutputStream());
            System.out.println("客户端已连接成功:");
            String formula = scanner.nextLine();
            String regex = ".*[^0-9|+|\\-|*|÷|(|)|\\s|/].*";
            if (formula.matches(regex)) {
                System.out.println("输入了非法字符");
                System.exit(1);
            }
            String output = "";
            MyBC myBC = new MyBC();
            try {
                //中缀转后缀
                output = MyBC.getrp(formula);
            } catch (Exception e) {
                System.out.println(e.getMessage());
                System.exit(1);
            }
            //使用AES进行后缀表达式的加密
            KeyGenerator kg = KeyGenerator.getInstance(mode);
            kg.init(128);
            SecretKey k = kg.generateKey();//生成密钥
            byte mkey[] = k.getEncoded();
            Cipher cp = Cipher.getInstance(mode);
            cp.init(Cipher.ENCRYPT_MODE, k);
            byte ptext[] = output.getBytes("UTF8");
            byte ctext[] = cp.doFinal(ptext);

            //将加密后的后缀表达式传送给服务器
            String out1 = BtoA.parseByte2HexStr(ctext);
            out.writeUTF(out1);

            //创建客户端DH算法公、私钥
            DH.createPubAndPriKey("Clientpub.txt","Clientpri.txt");

            //将客户端公钥传给服务器
            FileInputStream fp = new FileInputStream("Clientpub.txt");
            ObjectInputStream bp = new ObjectInputStream(fp);
            Key kp = (Key) bp.readObject();
            ByteArrayOutputStream baos = new ByteArrayOutputStream();
            ObjectOutputStream oos = new ObjectOutputStream(baos);
            oos.writeObject(kp);
            byte[] kb = baos.toByteArray();
            String pop = BtoA.parseByte2HexStr(kb);
            out.writeUTF(pop);
            Thread.sleep(1000);

            //接收服务器公钥
            String push = in.readUTF();
            byte np[] = AtoB.parseHexStr2Byte(push);
            ObjectInputStream ois = new ObjectInputStream (new ByteArrayInputStream (np));
            Key k2 = (Key)ois.readObject();;
            FileOutputStream f2 = new FileOutputStream("Serverpub.txt");
            ObjectOutputStream b2 = new ObjectOutputStream(f2);
            b2.writeObject(k2);

            //生成共享信息,并生成AES密钥
            SecretKeySpec key = Agree.createKey("Serverpub.txt", "Clientpri.txt");

            //对加密后缀表达式的密钥进行加密,并传给服务器
            cp.init(Cipher.ENCRYPT_MODE, key);
            byte ckey[] = cp.doFinal(mkey);
            String Key = BtoA.parseByte2HexStr(ckey);
            out.writeUTF(Key);

            //接收服务器回答
            String s = in.readUTF();
            System.out.println("客户收到服务器的回答:" + s);
        } catch (Exception e) {
            System.out.println("服务器已断开" + e);
        }
    }
}

DH.java

import javax.crypto.spec.DHParameterSpec;
import java.io.FileOutputStream;
import java.io.ObjectOutputStream;
import java.math.BigInteger;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.PrivateKey;
import java.security.PublicKey;

public class DH {
    private static final byte SKIP1024_MODULUS_BYTES[] = {
            (byte)0xF4, (byte)0x88, (byte)0xFD, (byte)0x58,
            (byte)0x4E, (byte)0x49, (byte)0xDB, (byte)0xCD,
            (byte)0x20, (byte)0xB4, (byte)0x9D, (byte)0xE4,
            (byte)0x91, (byte)0x07, (byte)0x36, (byte)0x6B,
            (byte)0x33, (byte)0x6C, (byte)0x38, (byte)0x0D,
            (byte)0x45, (byte)0x1D, (byte)0x0F, (byte)0x7C,
            (byte)0x88, (byte)0xB3, (byte)0x1C, (byte)0x7C,
            (byte)0x5B, (byte)0x2D, (byte)0x8E, (byte)0xF6,
            (byte)0xF3, (byte)0xC9, (byte)0x23, (byte)0xC0,
            (byte)0x43, (byte)0xF0, (byte)0xA5, (byte)0x5B,
            (byte)0x18, (byte)0x8D, (byte)0x8E, (byte)0xBB,
            (byte)0x55, (byte)0x8C, (byte)0xB8, (byte)0x5D,
            (byte)0x38, (byte)0xD3, (byte)0x34, (byte)0xFD,
            (byte)0x7C, (byte)0x17, (byte)0x57, (byte)0x43,
            (byte)0xA3, (byte)0x1D, (byte)0x18, (byte)0x6C,
            (byte)0xDE, (byte)0x33, (byte)0x21, (byte)0x2C,
            (byte)0xB5, (byte)0x2A, (byte)0xFF, (byte)0x3C,
            (byte)0xE1, (byte)0xB1, (byte)0x29, (byte)0x40,
            (byte)0x18, (byte)0x11, (byte)0x8D, (byte)0x7C,
            (byte)0x84, (byte)0xA7, (byte)0x0A, (byte)0x72,
            (byte)0xD6, (byte)0x86, (byte)0xC4, (byte)0x03,
            (byte)0x19, (byte)0xC8, (byte)0x07, (byte)0x29,
            (byte)0x7A, (byte)0xCA, (byte)0x95, (byte)0x0C,
            (byte)0xD9, (byte)0x96, (byte)0x9F, (byte)0xAB,
            (byte)0xD0, (byte)0x0A, (byte)0x50, (byte)0x9B,
            (byte)0x02, (byte)0x46, (byte)0xD3, (byte)0x08,
            (byte)0x3D, (byte)0x66, (byte)0xA4, (byte)0x5D,
            (byte)0x41, (byte)0x9F, (byte)0x9C, (byte)0x7C,
            (byte)0xBD, (byte)0x89, (byte)0x4B, (byte)0x22,
            (byte)0x19, (byte)0x26, (byte)0xBA, (byte)0xAB,
            (byte)0xA2, (byte)0x5E, (byte)0xC3, (byte)0x55,
            (byte)0xE9, (byte)0x2F, (byte)0x78, (byte)0xC7
    };
    private static final BigInteger SKIP1024_MODULES = new BigInteger(1, SKIP1024_MODULUS_BYTES);
    private static final BigInteger SKIP1024_BASE = BigInteger.valueOf(2);

    public static void createPubAndPriKey(String inpub,String inpri) throws Exception{
        DHParameterSpec dhp = new DHParameterSpec(SKIP1024_MODULES, SKIP1024_BASE);
        KeyPairGenerator kpg = KeyPairGenerator.getInstance("DH");
        kpg.initialize(dhp);
        KeyPair kp = kpg.generateKeyPair();
        PublicKey pbk = kp.getPublic();
        PrivateKey prk = kp.getPrivate();

        FileOutputStream f1 = new FileOutputStream(inpub);
        ObjectOutputStream b1 = new ObjectOutputStream(f1);
        b1.writeObject(pbk);
        //文件名通过命令行参数指定,第一个命令行参数对应的文件保存公钥,第二个命令行参数对应的文件保存私钥
        FileOutputStream f2 = new FileOutputStream(inpri);
        ObjectOutputStream b2 = new ObjectOutputStream(f2);
        b2.writeObject(prk);

    }
}

Server.java

import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
import java.io.*;
import java.net.ServerSocket;
import java.net.Socket;
import java.security.Key;

public class Server {
    public static void main(String[] args) {
        String mode = "AES";
        ServerSocket serverForClient = null;
        Socket socketOnServer = null;
        DataOutputStream out = null;
        DataInputStream in = null;
        try{
            serverForClient = new ServerSocket(2010);
        }catch (IOException e1){
            System.out.println(e1);
        }
        String result;
        try{
            System.out.println("等待客户呼叫:");
            socketOnServer = serverForClient.accept();
            out = new DataOutputStream(socketOnServer.getOutputStream());
            in = new DataInputStream(socketOnServer.getInputStream());

            //接收加密后的后缀表达式
            String cformula = in.readUTF();
            byte cipher[] = AtoB.parseHexStr2Byte(cformula);


            //接收Client端公钥
            String push = in.readUTF();
            byte np[] = AtoB.parseHexStr2Byte(push);

            //生成服务器共、私钥
            DH.createPubAndPriKey("Serverpub.txt","Serverpri.txt");

            //将服务器公钥传给Client端
            FileInputStream fp = new FileInputStream("Serverpub.txt");
            ObjectInputStream bp = new ObjectInputStream(fp);
            Key kp = (Key) bp.readObject();
            ByteArrayOutputStream baos = new ByteArrayOutputStream();
            ObjectOutputStream oos = new ObjectOutputStream(baos);
            oos.writeObject(kp);
            byte[] kb = baos.toByteArray();
            String pop = BtoA.parseByte2HexStr(kb);
            out.writeUTF(pop);
            Thread.sleep(1000);

            //生成共享信息,并生成AES密钥
            SecretKeySpec key = Agree.createKey("Serverpub.txt","Clientpri.txt");

            String k = in.readUTF();//读取加密后密钥
            byte[] encryptKey = AtoB.parseHexStr2Byte(k);

            //对加密后密钥进行解密
            Cipher cp = Cipher.getInstance(mode);
            cp.init(Cipher.DECRYPT_MODE,key);
            byte decryptKey [] = cp.doFinal(encryptKey);

            //对密文进行解密
            SecretKeySpec plainkey=new  SecretKeySpec(decryptKey,mode);
            cp.init(Cipher.DECRYPT_MODE, plainkey);
            byte []plain=cp.doFinal(cipher);

            //计算后缀表达式结果
            String formula = new String(plain);
            try{
                Float s1 = MyDC.calrp(formula);
                result = s1.toString();
                //后缀表达式formula调用MyDC进行求值
            }catch (Exception e){
                result = e.getMessage();
            }
            //将计算结果传给Client端
            out.writeUTF(result);
        }catch (Exception e){
            System.out.println("客户已断开"+e);
        }
    }
}

运行效果


检查点五:

结对编程:
1人负责客户端,一人负责服务器
0. 注意责任归宿,要会通过测试证明自己没有问题

  1. 基于Java Socket实现客户端/服务器功能,传输方式用TCP
  2. 客户端让用户输入中缀表达式,然后把中缀表达式调用MyBC.java的功能转化为后缀表达式,把后缀表达式用3DES或AES算法加密通过网络把密文和明文的MD5値发送给服务器
  3. 客户端和服务器用DH算法进行3DES或AES算法的密钥交换
  4. 服务器接收到后缀表达式表达式后,进行解密,解密后计算明文的MD5值,和客户端传来的MD5进行比较,一致则调用MyDC.java的功能计算后缀表达式的值,把结果发送给客户端
  5. 客户端显示服务器发送过来的结果
  6. 上传测试结果截图和码云链接

编写代码

Client.java

import java.io.*;
import java.net.*;
import java.util.Scanner;

public class Client5 {
    public static void main(String args[]) throws Exception {
        String key1="";
        int n1=-1;
        byte [] a1=new byte[128];
        try{  File f=new File("key1.dat");
            InputStream in = new FileInputStream(f);
            while((n1=in.read(a1,0,100))!=-1) {
                key1=key1+new String (a1,0,n1);
            }
            in.close();
        }
        catch(IOException e) {
            System.out.println("File read Error"+e);
        }
        String sharekey="";
        int n=-1;
        byte [] a=new byte[128];
        try{  File f=new File("key1.dat");
            InputStream in = new FileInputStream(f);
            while((n=in.read(a,0,100))!=-1) {
                sharekey=sharekey+new String (a,0,n);
            }
            in.close();
        }
        catch(IOException e) {
            System.out.println("File read Error"+e);
        }
        Socket mysocket;
        DataInputStream in=null;
        DataOutputStream out=null;
        System.out.println("请输入算式:");
        Scanner scanner = new Scanner(System.in);
        String str = scanner.nextLine();//输入算式
        str=MyBC.getrp(str);
        String secret=Encoder.AESEncode(key1, str);//客户端对表达式进行加密
        String md=DigestPass.MD5(str);//客户端提供的MD5
        key1 = Encoder.AESEncode(sharekey,key1);//客户端对密钥进行DH加密
        try{  mysocket=new Socket("127.1.0.0",2010);
            in=new DataInputStream(mysocket.getInputStream());
            out=new DataOutputStream(mysocket.getOutputStream());
            out.writeUTF(key1);
            out.writeUTF(secret);
            out.writeUTF(md);
            String  s=in.readUTF();   //in读取信息,堵塞状态
            System.out.println("客户收到服务器的回答:"+s);
            Thread.sleep(50000);
        }
        catch(Exception e) {
            System.out.println("服务器已断开"+e);
        }
    }
}

Server.java

import java.io.*;
import java.net.*;
public class Server {
    public static void main(String args[]) throws  IOException{
        String sharekey="";
        int n=-1;
        byte [] a=new byte[128];
        try{  File f=new File("key1.dat");
            InputStream in = new FileInputStream(f);
            while((n=in.read(a,0,100))!=-1) {
                sharekey=sharekey+new String (a,0,n);
            }
            in.close();
        }
        catch(IOException e) {
            System.out.println("File read Error"+e);
        }

        ServerSocket serverForClient=null;
        Socket socketOnServer=null;
        DataOutputStream out=null;
        DataInputStream  in=null;
        try { serverForClient = new ServerSocket(2010);
        }
        catch(IOException e1) {
            System.out.println(e1);
        }
        try{ System.out.println("等待客户呼叫");
            socketOnServer = serverForClient.accept(); //堵塞状态,除非有客户呼叫
            out=new DataOutputStream(socketOnServer.getOutputStream());
            in=new DataInputStream(socketOnServer.getInputStream());
            String keyone =in.readUTF();//读取被DH算法加密的密钥
            String truekey = Encoder.AESDncode(sharekey,keyone);//使用共享密钥对被加密的原密钥解密。
            String secret =in.readUTF(); // in读取信息,堵塞状态
            System.out.println("服务器收到的信息:"+secret);
            String mdClient=in.readUTF();
            System.out.println("客户端提供的MD5为:"+ mdClient);
            String clear = Encoder.AESDncode(truekey,secret);//使用原密钥解密表达式
            Float answer=MyDC.calrp(clear);
            if((mdClient.equals(DigestPass.MD5(clear)))==true) {//判断MD5值是否相等,若相等,则返回答案
                System.out.println("MD5值匹配");
                System.out.println("服务器提供的解密:" + clear);
                System.out.println("服务器解出密文的MD5为:" + DigestPass.MD5(clear));
                out.writeUTF(answer + "");
            }
            Thread.sleep(500);
        }
        catch(Exception e) {
            System.out.println("客户已断开"+e);
        }
    }
}

DigestPass.java

import java.security.*;
public class DigestPass{
    static String MD5(String str) throws Exception{
        MessageDigest m=MessageDigest.getInstance("MD5");
        m.update(str.getBytes("UTF8"));
        byte s[ ]=m.digest( );
        String result="";
        for (int i=0; i<s.length; i++){
            result+=Integer.toHexString((0x000000ff & s[i]) |
                    0xffffff00).substring(6);
        }
        return result;
    }
}

SEnc.java

import java.io.*;
import java.security.*;
import javax.crypto.*;
public class SEnc{
    public static void main(String args[]) throws Exception{
        String s="Hello World!";
        FileInputStream f=new FileInputStream("key1.dat");
        ObjectInputStream b=new ObjectInputStream(f);
        Key k=(Key)b.readObject( );
        Cipher cp=Cipher.getInstance("DESede");
        cp.init(Cipher.ENCRYPT_MODE, k);
        byte ptext[]=s.getBytes("UTF8");
        for(int i=0;i<ptext.length;i++){
            System.out.print(ptext[i]+",");
        }
        System.out.println("");
        byte ctext[]=cp.doFinal(ptext);
        for(int i=0;i<ctext.length;i++){
            System.out.print(ctext[i] +",");
        }
        FileOutputStream f2=new FileOutputStream("SEnc.dat");
        f2.write(ctext);
    }
}

三、问题与解决

问题一:

解决方案:
在IDEA上JDK8以上的版本取消了sun.misc的引,但由于找不到其他可以代替BASE将字节码转换为字符串的方式,这里将JDK的版本还原到了8.0

四、感悟

本次实验是对个人编码理解能力与操作能力的考验,感觉自己在许多方面还需要加强,结对的过程中,文航给我提供了很多帮助,很是感谢。

五、码云链接

https://gitee.com/xinhaoa/projects

posted @ 2019-06-02 15:57  20175105鑫浩  阅读(159)  评论(0编辑  收藏  举报
}