20165328 實驗五《網絡安全編程》實驗報告

時間 2019-11-25

原文原文鏈接

1、網絡編程與安全-1：html

實驗要求：java

參考http://www.cnblogs.com/rocedu/p/6766748.html#SECDSA
結對實現中綴表達式轉後綴表達式的功能 MyBc.java
結對實驗從上面功能中獲取的表達式中實現後綴表達式求值的功能，調用MyDc.java

實驗代碼：算法

My.Bc：

import java.util.*;
public class MyBC {
    private static LinkedList<String> op1 = new LinkedList<>();
    private static LinkedList<String> op2 = new LinkedList<>();
    private static StringBuilder a = new StringBuilder();

    public StringBuilder houzhui(LinkedList<String> list) {
        Iterator<String> i = list.iterator();
        while (i.hasNext()) {
            String s = i.next();
            if (isOperator(s)) {
                if (op1.isEmpty()) {
                    op1.push(s);
                } else {
                    if (priority(op1.peek()) <= priority(s) && !s.equals(")")) {
                        op1.push(s);
                    } else if (!s.equals(")") && priority(op1.peek()) > priority(s)) {
                        while (op1.size() != 0 && priority(op1.peek()) >= priority(s)
                                && !op1.peek().equals("(")) {
                            if (!op1.peek().equals("(")) {
                                String operator = op1.pop();
                                a.append(operator).append(" ");
                                op2.push(operator);
                            }
                        }
                        op1.push(s);
                    } else if (s.equals(")")) {
                        while (!op1.peek().equals("(")) {
                            String operator = op1.pop();
                            a.append(operator).append(" ");
                            op2.push(operator);
                        }
                        op1.pop();
                    }
                }
            } else {
                a.append(s).append(" ");
                op2.push(s);
            }
        }
        if (!op1.isEmpty()) {
            Iterator<String> iterator = op1.iterator();
            while (iterator.hasNext()) {
                String operator = iterator.next();
                a.append(operator).append(" ");
                op2.push(operator);
                iterator.remove();
            }
        }
        return a;
    }

    private static boolean isOperator(String oper) {
        if (oper.equals("+") || oper.equals("-") || oper.equals("/") || oper.equals("*")
                || oper.equals("(") || oper.equals(")")) {
            return true;
        }
        return false;
    }

    private static int priority(String s) {
        switch (s) {
            case "+":
                return 1;
            case "-":
                return 1;
            case "*":
                return 2;
            case "/":
                return 2;
            case "(":
                return 3;
            case ")":
                return 3;
            default:
                return 0;
        }
    }
}

My.Dc：express

import java.util.LinkedList;
import java.util.*;

import java.util.*;



public class MyDC {
    public static int evaluate(StringBuilder b) {
        LinkedList<String> mList = new LinkedList<>();
        String[] postStr = b.toString().split(" ");
        int result;
        for (String s : postStr) {
            if (fuhao(s)) {
                if (!mList.isEmpty()) {
                    int num1 = Integer.valueOf(mList.pop());
                    int num2 = Integer.valueOf(mList.pop());
                    if (s.equals("/") && num1 == 0) {
                        System.out.println("除數不能爲0");
                        return 0;
                    }
                    int newNum = cal(num2, num1, s);
                    mList.push(String.valueOf(newNum));
                }
            } else {
                mList.push(s);
            }
        }


        result=Integer.parseInt(mList.pop());

        return result;
    }

    private static boolean fuhao(String a) {
        if (a.equals("+") || a.equals("-") || a.equals("/") || a.equals("*")
                || a.equals("(") || a.equals(")")) {
            return true;
        }
        return false;
    }


    private static int cal(int num1, int num2, String operator) {
        switch (operator) {
            case "+":
                return num1 + num2;
            case "-":
                return num1 - num2;
            case "*":
                return num1 * num2;
            case "/":
                return num1 / num2;
            default:
                return 0;
        }
    }
}

My.DcTest：編程

import java.util.LinkedList;
import java.util.*;

public class MyDCTest {
    public static void main(String[] args){
        LinkedList<String> list=new LinkedList<>();
        StringBuilder result1;
        int result2;
        String expression, again;
        System.out.println("請輸入一箇中綴表達式並以#結束");
        Scanner scanner=new Scanner(System.in);
        String s;
        while (!(s=scanner.next()).equals("#")) {
            list.add(s);
        }
        MyBC hz=new MyBC();
        result1 = hz.houzhui(list);
        System.out.println("後綴表達式： "+result1);
        MyDC evaluator = new MyDC();
        result2 = evaluator.evaluate(result1);
        System.out.println("That expression equals " + result2);
        System.out.println();

    }
}

實驗截圖：數組

2、網絡安全編程-2：安全

實驗要求：服務器

結對編程：1人負責客戶端，1人負責服務器
注意責任歸宿，要會經過測試證實本身沒有問題
基於Java Scokect實現客戶端/服務器功能，傳輸方式用TCP
客戶端讓用戶輸入中綴表達式，而後把中綴表達式用MyBc.java的功能轉化爲後綴表達式，把後綴表達式經過網絡發送給服務器
服務器接收到後綴表達式，調用MyDc.java的功能計算後綴表達式，把結果發送給客戶端
客戶端顯示服務器發送過來的結果
上傳測試截圖和碼雲連接

實驗代碼：網絡

Stack：

public class MyStack<T> implements SStack<T> {
    private Object element[];
    private int top;
    public MyStack(int size){
        this.element = new Object[Math.abs(size)];
        this.top = -1;
    }
    public MyStack() {
        this(64);
    }
    public boolean isEmpty() {
        return this.top == -1;
    }
    public void push(T x) {
        if(x==null)
            return;
        if(this.top == element.length-1){
            Object[] temp = this.element;
            this.element = new Object[temp.length*2];
            for(int i = 0; i < temp.length; i++)
                this.element[i] = temp[i];
        }
        this.top++;
        this.element[this.top] = x;
    }
    public T pop() {
        return this.top==-1 ? null:(T)this.element[this.top--];
    }
    public T get() {
        return this.top==-1 ? null:(T)this.element[this.top];
    }
}

SStack：併發

public interface SStack<T> {
    boolean isEmpty();
    void push(T x);
    T pop();
    T get();
}

Client（客戶端）

import java.net.*;
import java.io.*;
public class TCPClient {
    public static void main(String srgs[]) {
        try {
            //建立鏈接特定服務器的指定端口的Socket對象
            Socket socket = new Socket("127.0.0.1", 4421);
            //得到從服務器端來的網絡輸入流
            BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
            //得到從客戶端向服務器端輸出數據的網絡輸出流
            PrintWriter out=new PrintWriter(new BufferedWriter(new OutputStreamWriter(socket.getOutputStream())),true);
            //建立鍵盤輸入流，以便客戶端從鍵盤上輸入信息
            BufferedReader stdin = new BufferedReader(new InputStreamReader(System.in));
            System.out.print("請輸入待發送的數據：");
            String str=stdin.readLine(); //從鍵盤讀入待發送的數據
            String postfix = MyBC.toPostfix(str);
            out.println(postfix);  //經過網絡傳送到服務器
            str=in.readLine();//從網絡輸入流讀取結果
            System.out.println( "從服務器接收到的結果爲："+str); //輸出服務器返回的結果
        }
        catch (Exception e) {
            System.out.println(e);
        }
        finally{
            //stdin.close();
            //in.close();
            //out.close();
            //socket.close();
        }
    }
}

Service（服務器）：

import java.net.*;
import java.io.*;
public class TCPServer{
    public static void main(String srgs[]) {
        ServerSocket sc = null;
        Socket socket=null;
        try {
            NewMyDC evaluator = new NewMyDC();
            sc= new ServerSocket(4421);//建立服務器套接字
            System.out.println("端口號:" + sc.getLocalPort());
            System.out.println("服務器已經啓動...");
            socket = sc.accept();   //等待客戶端鏈接
            System.out.println("已經創建鏈接");
            //得到網絡輸入流對象的引用
            BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
            ////得到網絡輸出流對象的引用
            PrintWriter out=new PrintWriter(new BufferedWriter(new OutputStreamWriter(socket.getOutputStream())),true);
            String aline=in.readLine();//讀取客戶端傳送來的數據
            System.out.println("從客戶端接收到信息爲："+aline); //經過網絡輸出流返回結果給客戶端
            int result = evaluator.value(aline);
            out.println("Echo:" + result);
            out.close();
            in.close();
            sc.close();
        } catch (Exception e) {
            System.out.println(e);
        }
    }
}

實驗截圖：

3、網絡編程與安全-3：

實驗要求：

加密結對編程：1人負責客戶端，1人負責服務器
注意責任歸宿，要會經過測試證實本身沒有問題
基於Java Socket實現客戶端/服務器功能，傳輸方式用TCP
客戶端讓用戶輸入中綴表達式，而後把中綴表達式調用MyBc.java的功能轉化爲後綴表達式，把後綴表達式用3DES或AES算法加密後經過網絡把密文發送給服務器
服務器接收到後綴表達式後，進行解密（和客戶端協商密匙，能夠用數組保存）而後調用MyDc.java的功能計算後綴表達式的值，把結果發送給客戶端
客戶端顯示服務器發送過來的結果
上傳測試結果截圖和碼雲連接

實驗代碼：

客服端加密併發送給服務器代碼以下：

  KeyGenerator kg = KeyGenerator.getInstance("DESede");
            kg.init(168);
            SecretKey k = kg.generateKey();
            byte[] ptext2 = k.getEncoded();
            Socket socket = new Socket("127.0.0.1", 4421);
            BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
            PrintWriter out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(socket.getOutputStream())), true);
            BufferedReader stdin = new BufferedReader(new InputStreamReader(System.in));
            //RSA算法，使用服務器端的公鑰對DES的密鑰進行加密
            FileInputStream f3 = new FileInputStream("Skey_RSA_pub.dat");
            ObjectInputStream b2 = new ObjectInputStream(f3);
            RSAPublicKey pbk = (RSAPublicKey) b2.readObject();
            BigInteger e = pbk.getPublicExponent();
            BigInteger n = pbk.getModulus();
            BigInteger m = new BigInteger(ptext2);
            BigInteger c = m.modPow(e, n);
            String cs = c.toString();
            out.println(cs); // 經過網絡將加密後的祕鑰傳送到服務器
            System.out.print("請輸入待發送的數據：");
            //用DES加密明文獲得密文
            String s = stdin.readLine(); // 從鍵盤讀入待發送的數據
            String postfix = MyBC.toPostfix(s);
            Cipher cp = Cipher.getInstance("DESede");
            cp.init(Cipher.ENCRYPT_MODE, k);
            byte ptext[] = postfix.getBytes("UTF8");
            byte ctext[] = cp.doFinal(ptext);
            String str = parseByte2HexStr(ctext);
            out.println(str); // 經過網絡將密文傳送到服務器

服務器解密，計算結果併發送給客戶端代碼以下：

String line = in.readLine();
            BigInteger cipher = new BigInteger(line);
            FileInputStream f = new FileInputStream("Skey_RSA_priv.dat");
            ObjectInputStream b = new ObjectInputStream(f);
            RSAPrivateKey prk = (RSAPrivateKey) b.readObject();
            BigInteger d = prk.getPrivateExponent();
            BigInteger n = prk.getModulus();//mod n
            BigInteger m = cipher.modPow(d, n);//m=d (mod n)
            System.out.println("d= " + d);
            System.out.println("n= " + n);
            System.out.println("m= " + m);
            byte[] keykb = m.toByteArray();
            // 使用DES對密文進行解密
            String readline = in.readLine();//讀取客戶端傳送來的數據
            FileInputStream f2 = new FileInputStream("keykb1.dat");
            int num2 = f2.available();
            byte[] ctext = parseHexStr2Byte(readline);
            Key k = new SecretKeySpec(keykb,"DESede");
            Cipher cp = Cipher.getInstance("DESede");
            cp.init(Cipher.DECRYPT_MODE, k);
            byte[] ptext = cp.doFinal(ctext);
            String p = new String(ptext, "UTF8");//編碼轉換
            System.out.println("從客戶端接收到信息爲：" + p); //打印解密結果
            NewMyDC evaluator = new NewMyDC();
            int _result = evaluator.value(p);
            out.println("Echo:" + _result);
            out.close();
            in.close();
            link.close();

服務器代碼以下：

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;

import java.io.*;
import java.security.*;
import javax.crypto.*;
import javax.crypto.spec.*;

public class SocketService {
    public static void main(String[] args) throws IOException, IllegalBlockSizeException, InvalidKeyException, BadPaddingException, NoSuchAlgorithmException, NoSuchPaddingException {
        SocketService socketService = new SocketService();
        try {
            socketService.oneServer();
        } catch (IOException e) {
            e.printStackTrace();
        } catch (NoSuchPaddingException e) {
            e.printStackTrace();
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        } catch (InvalidKeyException e) {
            e.printStackTrace();
        } catch (BadPaddingException e) {
            e.printStackTrace();
        } catch (IllegalBlockSizeException e) {
            e.printStackTrace();
        }
    }
    public  void oneServer() throws IOException, NoSuchPaddingException, NoSuchAlgorithmException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException {
        MyDC mydc=new MyDC();

        try{
            ServerSocket server=null;
            try{
                server=new ServerSocket(5204);
                System.out.println("服務器啓動成功");
            }catch(Exception e) {
                System.out.println("沒有啓動監聽："+e);
            }
            Socket socket=null;
            try{
                socket=server.accept();
            }catch(Exception e) {
                System.out.println("Error."+e);
            }
            String line;
            BufferedReader in=new BufferedReader(new InputStreamReader(socket.getInputStream()));
            PrintWriter writer=new PrintWriter(socket.getOutputStream());

            line=in.readLine();
            System.out.printf("密文=%s\n",line);
            // 獲取密鑰
            byte[]ctext=line.getBytes("ISO-8859-1");
            FileInputStream  f2=new FileInputStream("keykb1.dat");
            int num2=f2.available();
            byte[ ] keykb=new byte[num2];
            System.out.printf("\n");
            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);
            // 顯示明文

            String p=new String(ptext,"UTF8");




            System.out.println("明文:"+p);
            int a;
            String Np="";
            for(int i=1;i<p.length();i++)
                Np+=p.charAt(i);
            a=mydc.evaluate(Np);

                writer.println(a);
                writer.flush();

            writer.close();
            in.close();
            socket.close();
            server.close();
        }catch(Exception e) {
            System.out.println("Error."+e);
        }
        // 獲取密文

    }

}

客戶端代碼以下：

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.Socket;

import java.io.*;
import java.security.*;
import java.util.Arrays;
import javax.crypto.*;

public class SocketClient {
    // 搭建客戶端
    public static void main(String[] args) throws IOException, ClassNotFoundException, NoSuchPaddingException, NoSuchAlgorithmException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException {
        MyBC mybc=new MyBC();
        try {
            Socket socket = new Socket("192.168.43.166",5329);
            System.out.println("客戶端啓動成功");
            BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
            PrintWriter write = new PrintWriter(socket.getOutputStream());
            BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
            String readline;
            System.out.println("Client:" );
            readline = br.readLine();
            String line=mybc.evaluate(readline);
            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[]=line.getBytes("UTF-8");


            byte ctext[]=cp.doFinal(ptext);
            String Str=new String(ctext,"ISO-8859-1");

            write.println(Str);
            write.flush();






                System.out.println("Server return:" + in.readLine());

            write.close();
            in.close();
            socket.close();

        } catch (Exception e) {
            System.out.println("can not listen to:" + e);
        }

    }

}

實驗截圖：

4、網絡安全與編程-4：

實驗要求：

密匙分發結對編程：1人負責客戶端，1人負責服務器
注意責任歸宿，要會經過測試證實本身沒問題
基於Java Socket實現客戶端/服務器功能，傳輸方式用TCP
客戶端讓用戶輸入中綴表達式，而後把中綴表達式用MyBc.java的功能轉化爲後綴表達式，把後綴表達式用3DES或AES算法加密經過網絡把密文發送給服務器
客戶端和服務器用DH算法進行3DES或AES算法的密匙交換
服務器接收到後綴表達式後，進行解密，而後調用MyDc.java的功能計算後綴表達式的值，把結果發送給客戶端
客戶端顯示發送過來的結果
上傳測試結果截圖和碼雲連接：

實驗代碼：

DH公匙代碼以下：

public class Key_DH{
    private static final byte skip1024ModulusBytes[] = {
            (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
    };
    // The SKIP 1024 bit modulus
    private static final BigInteger skip1024Modulus
            = new BigInteger(1, skip1024ModulusBytes);
    // The base used with the SKIP 1024 bit modulus
    private static final BigInteger skip1024Base = BigInteger.valueOf(2);
    public static void main(String args[ ]) throws Exception{
        DHParameterSpec DHP=
                new DHParameterSpec(skip1024Modulus,skip1024Base);

        KeyPairGenerator kpg= KeyPairGenerator.getInstance("DH");
        kpg.initialize(DHP);
        KeyPair kp=kpg.genKeyPair();

        PublicKey pbk=kp.getPublic();
        PrivateKey prk=kp.getPrivate();
        // 保存公鑰
        FileOutputStream  f1=new FileOutputStream(args[0]);
        ObjectOutputStream b1=new  ObjectOutputStream(f1);
        b1.writeObject(pbk);
        // 保存私鑰
        FileOutputStream  f2=new FileOutputStream(args[1]);
        ObjectOutputStream b2=new  ObjectOutputStream(f2);
        b2.writeObject(prk);
    }
}

建立共享密匙：

public class KeyAgree{
    public static void main(String args[ ]) throws Exception{
        // 讀取對方的DH公鑰
        FileInputStream f1=new FileInputStream(args[0]);
        ObjectInputStream b1=new ObjectInputStream(f1);
        PublicKey  pbk=(PublicKey)b1.readObject( );
//讀取本身的DH私鑰
        FileInputStream f2=new FileInputStream(args[1]);
        ObjectInputStream b2=new ObjectInputStream(f2);
        PrivateKey  prk=(PrivateKey)b2.readObject( );
        // 執行密鑰協定
        KeyAgreement ka=KeyAgreement.getInstance("DH");
        ka.init(prk);
        ka.doPhase(pbk,true);
        //生成共享信息
        byte[ ] sb=ka.generateSecret();
        for(int i=0;i<sb.length;i++){
            System.out.print(sb[i]+",");
        }
        SecretKeySpec k=new  SecretKeySpec(sb,"DESede");
    }
}

實驗截圖：

5、網絡安全編程-5：

實驗要求：

完整性校驗結對編程：1人負責客戶端，1人負責服務器
注意責任歸宿：要會經過測試證實本身沒有問題
基於Java Socket實現客戶端/服務器功能，傳輸方式用TCP
客戶端讓用戶輸入中綴表達式，而後把中綴表達式調用MyBc.java的功能轉化爲後綴表達式，把後綴表達式用3DES或AES算法進行加密經過網絡把密文發送給服務器
客服端和服務器用DH算法進行3DES或AES算法的密匙交換
服務器接收到後綴表達式後進行解密，解密後計算明文的MD5值，和客戶端傳過來的MD5值進行比較，一致則調用MyDc.java算法計算後綴表達式的值，把結果發送給客戶端
客戶端顯示發送過來的結果
上傳測試結果截圖和碼雲連接

實驗代碼：

Service：

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;

import java.io.*;
import java.security.*;
import javax.crypto.*;
import javax.crypto.spec.*;

public class SocketService {
    public static void main(String[] args) throws IOException, IllegalBlockSizeException, InvalidKeyException, BadPaddingException, NoSuchAlgorithmException, NoSuchPaddingException {
        SocketService socketService = new SocketService();
        try {
            socketService.oneServer();
        } catch (IOException e) {
            e.printStackTrace();
        } catch (NoSuchPaddingException e) {
            e.printStackTrace();
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        } catch (InvalidKeyException e) {
            e.printStackTrace();
        } catch (BadPaddingException e) {
            e.printStackTrace();
        } catch (IllegalBlockSizeException e) {
            e.printStackTrace();
        }
    }
    public  void oneServer() throws IOException, NoSuchPaddingException, NoSuchAlgorithmException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException {
        MyDC mydc=new MyDC();

        try{
            ServerSocket server=null;
            try{
                server=new ServerSocket(5329);
                System.out.println("服務器啓動成功");
            }catch(Exception e) {
                System.out.println("沒有啓動監聽："+e);
            }
            Socket socket=null;
            try{
                socket=server.accept();
            }catch(Exception e) {
                System.out.println("Error."+e);
            }
            String line;
            BufferedReader in=new BufferedReader(new InputStreamReader(socket.getInputStream()));
            PrintWriter writer=new PrintWriter(socket.getOutputStream());

            line=in.readLine();
            String line1=in.readLine();
            System.out.printf("密文=%s\n",line);
            // 獲取密鑰
            byte[]ctext=line.getBytes("ISO-8859-1");
            FileInputStream  f2=new FileInputStream("keykb1.dat");
            int num2=f2.available();
            byte[ ] keykb=new byte[num2];
            System.out.printf("\n");
            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);
            // 顯示明文

            String p=new String(ptext,"UTF8");

            int a;


            System.out.println("明文:"+p);
            String Np="";
            for(int i=1;i<p.length();i++)
                Np+=p.charAt(i);
            a=mydc.evaluate(Np);
            String x=p;
            MessageDigest m=MessageDigest.getInstance("MD5");
            m.update(x.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);
            }
            if(!(line1.equals(result)))System.out.printf("MD5比對正確！\n");

            writer.println(a);
            writer.flush();

            writer.close();
            in.close();
            socket.close();
            server.close();
        }catch(Exception e) {
            System.out.println("Error."+e);
        }
        // 獲取密文

    }

建立共享密匙：

public class KeyAgree{
    public static void main(String args[ ]) throws Exception{
        // 讀取對方的DH公鑰
        FileInputStream f1=new FileInputStream(args[0]);
        ObjectInputStream b1=new ObjectInputStream(f1);
        PublicKey  pbk=(PublicKey)b1.readObject( );
//讀取本身的DH私鑰
        FileInputStream f2=new FileInputStream(args[1]);
        ObjectInputStream b2=new ObjectInputStream(f2);
        PrivateKey  prk=(PrivateKey)b2.readObject( );
        // 執行密鑰協定
        KeyAgreement ka=KeyAgreement.getInstance("DH");
        ka.init(prk);
        ka.doPhase(pbk,true);
        //生成共享信息
        byte[ ] sb=ka.generateSecret();
        for(int i=0;i<sb.length;i++){
            System.out.print(sb[i]+",");
        }
        SecretKeySpec k=new  SecretKeySpec(sb,"DESede");
    }
}

實驗截圖：

6、實驗體會：

在最初拿到這個實驗時束手無策，不一樣與以往的實驗，此次實驗沒有現成的教程，一切都須要本身摸索實踐，我和結對夥伴本來準備分開完成客戶端和服務器代碼的，但在實踐編寫後咱們發現單獨編寫對咱們兩的難度太大了，因而咱們兩最終一塊兒編寫了全部的代碼，在此過程當中咱們兩互相啓迪，協同共進，雖然遇到了許多問題，但最終仍是迎刃而解，在這次試驗中，我十分感謝本身的夥伴，他給了許多幫助，也讓我瞭解學習了許多

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