实验五 网络编程与安全

20165225 实验五 网络编程与安全

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实验报告封面:

课程：Java程序设计  班级：1652班  姓名：王高源 学号：20165225

指导教师：娄嘉鹏 实验日期：2018年5月14日

实验时间：3：35 - 5：15 实验序号：实验5

实验名称：网络编程与安全

实验内容：

一、掌握Java Socket的相关内容；
二、学会创建客户端与服务器端之间的联系；
三、学习并应用密码学的相关内容

严禁抄袭，有该行为者实验成绩归零，并附加其余惩罚措施。

网络编程与安全一：

实验要求：

两人一组结对编程：

参考http://www.cnblogs.com/rocedu/p/6766748.html#SECDSA
结对实现中缀表达式转后缀表达式的功能 MyBC.java
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

实验代码：

Client

import java.net.*;
import java.io.*;
public class Client
{
    public static void main(String srgs[]) throws Exception
    {
        try
        {
            // 一、建立客户端Socket，指定服务器地址和端口
            Socket socket=new Socket("127.0.0.1",10000);
            System.out.println("客户端成功启动，等待服务器应答");
            // 二、获取输出流，向服务器端发送信息
            // 向本机的10001端口发出客户请求
            System.out.println("请输入中缀表达式：");
            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对象获得输出流，并构造PrintWriter对象
            //三、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对象获得输入流，并构造相应的BufferedReader对象
            String readline, infix, expression;
            readline = br.readLine(); // 从系统标准输入读入一字符串
            MyBC theTrans = new MyBC(readline);
            infix = theTrans.doTrans();
            StringBuilder newInfix = new StringBuilder(infix.replace(" ",""));
            for (int i = 1; i < infix.length()+(i+1)/2 ; i=i+2) {
                newInfix.insert(i," ");
            }
            System.out.println("后缀表达式：" + newInfix);
            expression=newInfix.toString();

            while (!readline.equals("end")) {
                // 若从标准输入读入的字符串为 "end"则中止循环
                write.println(expression);
                // 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立刻收到该字符串
                System.out.println("收到服务器的消息:" + 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
            //四、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(e);//输出异常
        }
        finally
        {

        }

    }
}

Server

import java.net.*;
import java.io.*;

public class Server{
    public static void main(String srgs[]) throws Exception
    {
        ServerSocket sc = null;
        Socket socket=null;
        try
        {
            MyDC evaluator = new MyDC();

            sc= new ServerSocket(10000);//建立服务器套接字
            System.out.println("端口号:" + sc.getLocalPort());
            System.out.println("服务器成功启动，等待客户端呼叫");
            socket = sc.accept();   //等待客户端链接
            System.out.println("已经创建链接");//得到网络输入流对象的引用
            BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));//得到网络输出流对象的引用
            PrintWriter out=new PrintWriter(new BufferedWriter(new OutputStreamWriter(socket.getOutputStream())),true);
            String aline2=in.readLine();
            System.out.println("客户端发来的信息为："+aline2);

            int ans = evaluator.evaluate(aline2);
            out.println(ans);
            System.out.println("result = "+ans);
        } catch (Exception e) {
            System.out.println(e);
        }
    }

    //十六进制和十进制转换
    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;
    }
}

MyDc

import java.util.StringTokenizer;
import java.util.Stack;

public class MyDC {
    /**
     * constant for addition symbol
     */
    private final char ADD = '+';
    /**
     * constant for subtraction symbol
     */
    private final char SUBTRACT = '-';
    /**
     * constant for multiplication symbol
     */
    private final char MULTIPLY = '*';
    /**
     * constant for division symbol
     */
    private final char DIVIDE = '/';
    /**
     * the stack
     */
    private Stack<Integer> stack;

    public MyDC() {
        stack = new Stack<Integer>();
    }

    public int evaluate(String expr) {
        int op1, op2, result = 0;
        String token;
        StringTokenizer tokenizer = new StringTokenizer(expr);
        while (tokenizer.hasMoreTokens()) {
            token = tokenizer.nextToken();

            //若是是运算符，调用isOperator
            if (isOperator(token)) {
                //从栈中弹出操做数2
                op2 = stack.pop();
                //从栈中弹出操做数1
                op1 = stack.pop();
                //根据运算符和两个操做数调用evalSingleOp计算result;
                result=evalSingleOp(token.charAt(0), op1, op2);
                //计算result入栈;
                stack.push(result);
            } else//若是是操做数
                //操做数入栈;
                stack.push(Integer.parseInt(token));
        }

        return result;
    }

    private boolean isOperator(String token) {
        return (token.equals("+") || token.equals("-") ||
                token.equals("*") || token.equals("/"));
    }

    private int evalSingleOp(char operation, int op1, int op2) {
        int result = 0;

        switch (operation) {
            case ADD:
                result = op1 + op2;
                break;
            case SUBTRACT:
                result = op1 - op2;
                break;
            case MULTIPLY:
                result = op1 * op2;
                break;
            case DIVIDE:
                result = op1 / op2;
        }

        return result;
    }
}

MyBc

public class MyBC {
    private Stack theStack;
    private String input;
    private String output = "";
    public MyBC(String in) {
        input = in;
        int stackSize = input.length();
        theStack = new Stack(stackSize);
    }
    public String doTrans() {
        for (int j = 0; j < input.length(); j++) {
            char ch = input.charAt(j);
            switch (ch) {
                case '+':
                case '-':
                    gotOper(ch, 1);
                    break;
                case '*':
                case '/':
                    gotOper(ch, 2);
                    break;
                case '(':
                    theStack.push(ch);
                    break;
                case ')':
                    gotParen(ch);
                    break;
                default:
                    output = output + ch;
                    break;
            }
        }
        while (!theStack.isEmpty()) {
            output = output + theStack.pop();
        }
        return output;
    }
    public void gotOper(char opThis, int prec1) {
        while (!theStack.isEmpty()) {
            char opTop = theStack.pop();
            if (opTop == '(') {
                theStack.push(opTop);
                break;
            }
            else {
                int prec2;
                if (opTop == '+' || opTop == '-')
                    prec2 = 1;
                else
                    prec2 = 2;
                if (prec2 < prec1) {
                    theStack.push(opTop);
                    break;
                }
                else
                    output = output + opTop;
            }
        }
        theStack.push(opThis);
    }
    public void gotParen(char ch){
        while (!theStack.isEmpty()) {
            char chx = theStack.pop();
            if (chx == '(')
                break;
            else
                output = output + chx;
        }
    }
    class Stack {
        private int maxSize;
        private char[] stackArray;
        private int top;
        public Stack(int max) {
            maxSize = max;
            stackArray = new char[maxSize];
            top = -1;
        }
        public void push(char j) {
            stackArray[++top] = j;
        }
        public char pop() {
            return stackArray[top--];
        }
        public char peek() {
            return stackArray[top];
        }
        public boolean isEmpty() {
            return (top == -1);
        }
    }
}

实验截图：

网络编程与安全二：

结对编程：1人负责客户端，一人负责服务器

注意责任归宿，要会经过测试证实本身没有问题
基于Java Socket实现客户端/服务器功能，传输方式用TCP
客户端让用户输入中缀表达式，而后把中缀表达式调用MyBC.java的功能转化为后缀表达式，把后缀表达式经过网络发送给服务器
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
客户端显示服务器发送过来的结果

实验代码：

Server

import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.FileInputStream;
import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;
public class Server1 {
    public static void main(String args[]) {
        ServerSocket serverForClient = null;
        Socket socketOnServer = null;
        DataOutputStream out = null;
        DataInputStream in = null;
        try {
            serverForClient = new ServerSocket(3001);
        } 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
            System.out.println("客户已链接");
            out = new DataOutputStream(socketOnServer.getOutputStream());
            in = new DataInputStream(socketOnServer.getInputStream());
            String leng = in.readUTF(); // in读取信息，堵塞状态
            byte ctext[] = new byte[Integer.parseInt(leng)];
            for (int i = 0;i<Integer.parseInt(leng);i++) {
                String temp = in.readUTF();
                ctext[i] = Byte.parseByte(temp);
            }
            // 获取密钥
            FileInputStream f2 = new FileInputStream("keykb1.txt");
            int num2 = f2.available();
            byte[] keykb = new byte[num2];
            f2.read(keykb);
            SecretKeySpec k = new SecretKeySpec(keykb, "DESede");
            // 解密
            Cipher cp = Cipher.getInstance("DESede");
            cp.init(Cipher.DECRYPT_MODE, k);
            byte[] ptext = cp.doFinal(ctext);
            System.out.println("后缀表达式已被解密：");
            for (int i = 0; i < ptext.length; i++) {
                System.out.print(ptext[i] + ",");
            }
            System.out.println("");
            // 显示明文
            String p = new String(ptext, "UTF8");
            System.out.println("服务器收到客户的请求:计算后缀表达式" + p);
            MyDC evaluator = new MyDC();
            out.writeUTF(evaluator.evaluate(p)+"");
        } catch (Exception e) {
            System.out.println("客户已断开" + e);
        }
    }
}

Client

实验截图：

网络编程与安全三：

加密结对编程：1人负责客户端，一人负责服务器

注意责任归宿，要会经过测试证实本身没有问题
基于Java Socket实现客户端/服务器功能，传输方式用TCP
客户端让用户输入中缀表达式，而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算法加密后经过网络把密文发送给服务器
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，能够用数组保存），而后调用MyDC.java的功能计算后缀表达式的值，把结果发送给客户端
客户端显示服务器发送过来的结果

实验代码：

Server

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;
import java.util.Optional;

public class Server2 {
    public static void main(String args[]) {
        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
            System.out.println("客户已链接");
            out = new DataOutputStream(socketOnServer.getOutputStream());
            in = new DataInputStream(socketOnServer.getInputStream());

            Key_DH.fun("Spub.txt","Spri.txt");
            int len = Integer.parseInt(in.readUTF());
            byte np[] = new byte[len];
            for (int i = 0;i<len;i++) {
                String temp = in.readUTF();
                np[i] = Byte.parseByte(temp);
            }
            ObjectInputStream ois = new ObjectInputStream (new ByteArrayInputStream (np));
            Key k2 = (Key)ois.readObject();;
            FileOutputStream f2 = new FileOutputStream("Cpub.txt");
            ObjectOutputStream b2 = new ObjectOutputStream(f2);
            b2.writeObject(k2);

            FileInputStream fp = new FileInputStream("Spub.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();
            out.writeUTF(kb.length + "");
            for (int i = 0; i < kb.length; i++) {
                out.writeUTF(kb[i] + "");
            }

            KeyAgree.fun("Cpub.txt","Spri.txt");

            String leng = in.readUTF(); // in读取信息，堵塞状态
            byte ctext[] = new byte[Integer.parseInt(leng)];
            for (int i = 0;i<Integer.parseInt(leng);i++) {
                String temp = in.readUTF();
                ctext[i] = Byte.parseByte(temp);
            }
            // 获取密钥
            FileInputStream f = new FileInputStream("sb.txt");
            byte[] keysb = new byte[24];
            f.read(keysb);
            System.out.println("公共密钥：");
            for (int i = 0;i<24;i++) {
                System.out.print(keysb[i]+",");
            }
            System.out.println("");
            SecretKeySpec k = new SecretKeySpec(keysb, "DESede");
            // 解密
            Cipher cp = Cipher.getInstance("DESede");
            cp.init(Cipher.DECRYPT_MODE, k);
            byte[] ptext = cp.doFinal(ctext);
            System.out.println("后缀表达式已被解密：");
            for (int i = 0; i < ptext.length; i++) {
                System.out.print(ptext[i] + ",");
            }
            System.out.println("");
            // 显示明文
            String p = new String(ptext, "UTF8");
            System.out.println("服务器收到客户的请求:计算后缀表达式" + p);
            MyDC evaluator = new MyDC();
            out.writeUTF(evaluator.evaluate(p)+"");
        } catch (Exception e) {
            System.out.println("客户已断开" + e);
        }
    }
}

实验编程：

网络编程与安全四：

密钥分发结对编程：1人负责客户端，一人负责服务器

注意责任归宿，要会经过测试证实本身没有问题
基于Java Socket实现客户端/服务器功能，传输方式用TCP
客户端让用户输入中缀表达式，而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算法加密经过网络把密文发送给服务器
客户端和服务器用DH算法进行3DES或AES算法的密钥交换
服务器接收到后缀表达式表达式后，进行解密，而后调用MyDC.java的功能计算后缀表达式的值，把结果发送给客户端
客户端显示服务器发送过来的结果

实验代码：

server

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

public class Server3 {
    public static void main(String args[]) {
        ServerSocket serverForClient = null;
        Socket socketOnServer = null;
        DataOutputStream out = null;
        DataInputStream in = null;
        try {
            serverForClient = new ServerSocket(3001);
        } 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
            System.out.println("客户已链接");
            out = new DataOutputStream(socketOnServer.getOutputStream());
            in = new DataInputStream(socketOnServer.getInputStream());

            Key_DH.fun("Spub.txt","Spri.txt");
            int len = Integer.parseInt(in.readUTF());
            byte np[] = new byte[len];
            for (int i = 0;i<len;i++) {
                String temp = in.readUTF();
                np[i] = Byte.parseByte(temp);
            }
            ObjectInputStream ois = new ObjectInputStream (new ByteArrayInputStream(np));
            Key k2 = (Key)ois.readObject();;
            FileOutputStream f2 = new FileOutputStream("Cpub.txt");
            ObjectOutputStream b2 = new ObjectOutputStream(f2);
            b2.writeObject(k2);

            FileInputStream fp = new FileInputStream("Spub.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();
            out.writeUTF(kb.length + "");
            for (int i = 0; i < kb.length; i++) {
                out.writeUTF(kb[i] + "");
            }

            KeyAgree.fun("Cpub.txt","Spri.txt");

            String leng = in.readUTF(); // in读取信息，堵塞状态
            byte ctext[] = new byte[Integer.parseInt(leng)];
            for (int i = 0;i<Integer.parseInt(leng);i++) {
                String temp = in.readUTF();
                ctext[i] = Byte.parseByte(temp);
            }
            String check = in.readUTF();
            // 获取密钥
            FileInputStream f = new FileInputStream("sb.txt");
            byte[] keysb = new byte[24];
            f.read(keysb);
            System.out.println("公共密钥：");
            for (int i = 0;i<24;i++) {
                System.out.print(keysb[i]+",");
            }
            System.out.println("");
            SecretKeySpec k = new SecretKeySpec(keysb, "DESede");
            // 解密
            Cipher cp = Cipher.getInstance("DESede");
            cp.init(Cipher.DECRYPT_MODE, k);
            byte[] ptext = cp.doFinal(ctext);
            System.out.println("后缀表达式已被解密：");
            for (int i = 0; i < ptext.length; i++) {
                System.out.print(ptext[i] + ",");
            }
            System.out.println("");
            // 显示明文
            String p = new String(ptext, "UTF8");
            String pMd5 = DigestPass.fun(p);
            System.out.println("解密后明文的MD5值："+pMd5);
            if (pMd5.equals(check)){
                System.out.println("和客户端的MD5值一致");
                System.out.println("服务器收到客户的请求:计算后缀表达式" + p);
                MyDC evaluator = new MyDC();
                out.writeUTF(evaluator.evaluate(p)+"");
            }
            else {
                System.out.println("警告：和客户端的MD5值不一致！");
            }
        } catch (Exception e) {
            System.out.println("客户已断开" + e);
        }
    }
}

实验截图：

网络编程与安全五：

完整性校验结对编程：1人负责客户端，一人负责服务器

注意责任归宿，要会经过测试证实本身没有问题
基于Java Socket实现客户端/服务器功能，传输方式用TCP
客户端让用户输入中缀表达式，而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算法加密经过网络把密文和明文的MD5値发送给服务器
客户端和服务器用DH算法进行3DES或AES算法的密钥交换
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
客户端显示服务器发送过来的结果

实验代码：

Client

import java.net.*;
import java.io.*;
public class Client
{
    public static void main(String srgs[]) throws Exception
    {
        try
        {
            // 一、建立客户端Socket，指定服务器地址和端口
            Socket socket=new Socket("127.0.0.1",10000);
            System.out.println("客户端成功启动，等待服务器应答");
            // 二、获取输出流，向服务器端发送信息
            // 向本机的10001端口发出客户请求
            System.out.println("请输入中缀表达式：");
            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对象获得输出流，并构造PrintWriter对象
            //三、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对象获得输入流，并构造相应的BufferedReader对象
            String readline, infix, expression;
            readline = br.readLine(); // 从系统标准输入读入一字符串
            MyBC theTrans = new MyBC(readline);
            infix = theTrans.doTrans();
            StringBuilder newInfix = new StringBuilder(infix.replace(" ",""));
            for (int i = 1; i < infix.length()+(i+1)/2 ; i=i+2) {
                newInfix.insert(i," ");
            }
            System.out.println("后缀表达式：" + newInfix);
            expression=newInfix.toString();

            while (!readline.equals("end")) {
                // 若从标准输入读入的字符串为 "end"则中止循环
                write.println(expression);
                // 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立刻收到该字符串
                System.out.println("收到服务器的消息:" + 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
            //四、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(e);//输出异常
        }
        finally
        {

        }

    }
}import java.net.*;
import java.io.*;
public class Client
{
    public static void main(String srgs[]) throws Exception
    {
        try
        {
            // 一、建立客户端Socket，指定服务器地址和端口
            Socket socket=new Socket("127.0.0.1",10000);
            System.out.println("客户端成功启动，等待服务器应答");
            // 二、获取输出流，向服务器端发送信息
            // 向本机的10001端口发出客户请求
            System.out.println("请输入中缀表达式：");
            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对象获得输出流，并构造PrintWriter对象
            //三、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对象获得输入流，并构造相应的BufferedReader对象
            String readline, infix, expression;
            readline = br.readLine(); // 从系统标准输入读入一字符串
            MyBC theTrans = new MyBC(readline);
            infix = theTrans.doTrans();
            StringBuilder newInfix = new StringBuilder(infix.replace(" ",""));
            for (int i = 1; i < infix.length()+(i+1)/2 ; i=i+2) {
                newInfix.insert(i," ");
            }
            System.out.println("后缀表达式：" + newInfix);
            expression=newInfix.toString();

            while (!readline.equals("end")) {
                // 若从标准输入读入的字符串为 "end"则中止循环
                write.println(expression);
                // 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立刻收到该字符串
                System.out.println("收到服务器的消息:" + 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
            //四、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(e);//输出异常
        }
        finally
        {

        }

    }
}

实验截图：

PSP(Personal Software Process)时间：

步骤	耗时	百分比
功能实现	55min	12.5%
测试	25min	15.6%
分析总结	20min	12.5%