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  • 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

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  • 原文地址:https://www.cnblogs.com/wxhblogs/p/10951682.html
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