实验五 网络编程与安全-----实验报告

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一、实验五 网络编程与安全-1

1.实验要求:
两人一组结对编程:

(1)参考http://www.cnblogs.com/rocedu/p/6766748.html#SECDSA ;

(2)结对实现中缀表达式转后缀表达式的功能 MyBC.java;

(3)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;

(4)上传测试代码运行结果截图和码云链接;

2.实验过程:
(1)MyDC代码:

import java.util.*;

public class MyDC {
    private final char ADD = '+';
    private final char SUBTRACT = '-';
    private final char MUTIPLY = '*';
    private final char DIVIDE = '/';
    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();
            if (isOperator(token)) {
                op2 = (stack.pop().intValue());
                op1 = (stack.pop().intValue());
                result = evalSingleOp(token.charAt(0), op1, op2);
                stack.push(result);
            } else {
                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 MUTIPLY:
                result = op1 * op2;
                break;
            case DIVIDE:
                result = op1 / op2;
        }
        return result;
    }
}

(2)MyDCTest代码:

import java.util.Scanner;

           public class MyDCTest  {

             public static void main (String[] args) {

             String expression, again;

             int result;

             try
             {
                   Scanner in = new Scanner(System.in);

                   do
                       {
                         MyDC evaluator = new MyDC();
                         System.out.println ("Enter a valid postfix expression: ");
                         expression = in.nextLine();

                         result = evaluator.evaluate (expression);
                         System.out.println();System.out.println ("That expression equals " + result);

                         System.out.print ("Evaluate another expression [Y/N]? ");
                         again = in.nextLine();
                         System.out.println();
                       }
                   while (again.equalsIgnoreCase("y"));
                 }
             catch (Exception IOException)
             {
                  System.out.println("Input exception reported");
                 }
           }
  }

(3)MyBC代码:

import java.util.*;
public class MyBC {
    public String result(String s) {
        Stack<String> sta = new Stack<String>();   //新建栈
        String str = "";
        StringTokenizer t=new StringTokenizer(s);
        while (t.hasMoreTokens()){    //依次遍历元素,转为后缀表达式
            String temp;
            String c;
            c=t.nextToken();
            if (c.equals("+") || c.equals("-")) {   //遇到优先级最低的“+”、“-”,弹出“(”之前的所有元素
                while (sta.size() != 0) {
                    temp = sta.pop();
                    if (temp.equals("(")) {
                        sta.push("(");
                        break;
                    }
                    str = str + temp + " ";
                }
                sta.push(c);
            } else if (c.equals("*")|| c.equals("÷")) {   //遇到优先级高的“*”、“/”,弹出“(”之前的“*”、“/”
                while (sta.size() != 0) {
                    temp = sta.pop();
                    if (temp.equals("(") || temp.equals("+") || temp.equals("-")) {
                        sta.push(temp);
                        break;
                    } else {
                        str = str + temp + " ";
                    }
                }
                sta.push(c);
            } else if (c.equals("(")) {     //遇到“(”直接入栈
                sta.push(c);
            } else if (c.equals(")")) {     //遇到“)”,弹出“(”之前的所有元素
                while (sta.size() != 0) {
                    temp = sta.pop();
                    if (temp.equals("(")) {
                        break;
                    } else {
                        str = str + temp + " ";
                    }
                }
            } else                       //遇到数字,直接存入数组
            {
                str = str + c + " ";
            }
        }
        while (sta.size()!=0){     //弹出栈中剩余的元素
            str=str+sta.pop()+" ";
        }
        return str;
    }
}

(4)Calculate代码:

import java.util.Scanner;
public class Caculate {
    public static void main(String[] args) {
        MyDC a = new MyDC();
        MyBC b = new MyBC();
        String str;
        int result;
        System.out.println("输入算式:");
        Scanner reader = new Scanner(System.in);
        str = reader.nextLine();
        str = b.result(str);
        result = a.evaluate(str);
        System.out.println("答案为:"+result);
    }
}

3.实验截图:
(1)测试MyDC截图:
技术图片

(2)计算结果截图:
技术图片

4.码云链接:
https://gitee.com/zzm-zcc/zhang_zhi_min/tree/master/%E5%AE%9E%E9%AA%8C5--1

实验五 网络编程与安全-2

1.实验要求:
结对编程:1人负责客户端,一人负责服务器;

(1)注意责任归宿,要会通过测试证明自己没有问题;

(2)基于Java Socket实现客户端/服务器功能,传输方式用TCP;

(3)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;

(4)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;

(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;

2.实验过程:
(1)Server代码(服务器端):

import java.io.*;
import java.net.*;
public class Server {
    public static void main(String args[]) {
        int answer;
        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 s=in.readUTF(); // in读取信息,堵塞状态
            System.out.println("服务器收到客户的提问:"+s);
            MyDC d=new MyDC();
            answer=d.evaluate(s);
            out.writeUTF(answer+"");
            Thread.sleep(500);
        }
        catch(Exception e) {
            System.out.println("客户已断开"+e);
        }
    }
}

(2)Client代码(客户端):

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

public class Client {
    public static void main(String args[]) {
        Socket mysocket;
        DataInputStream in=null;
        DataOutputStream out=null;
        try{  mysocket=new Socket("127.1.0.0",2010);
            in=new DataInputStream(mysocket.getInputStream());
            out=new DataOutputStream(mysocket.getOutputStream());
            System.out.println("请输入算式:");
            Scanner scanner=new Scanner(System.in);
            String str=scanner.nextLine();
            MyBC b=new MyBC();
            str=b.result(str);
            out.writeUTF(str);
            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);
        }
    }
}

注:任然需要MyDC代码与MyBC代码。
3.实验截图:
(1)服务器端截图:
技术图片

(2)客户端截图:
技术图片

4.码云链接:
https://gitee.com/zzm-zcc/zhang_zhi_min/commit/5377d0290f76f29daae2099b11936647409ae965

三、实验五 网络编程与安全-3

1.实验要求:
加密结对编程:1人负责客户端,一人负责服务器;

(1)注意责任归宿,要会通过测试证明自己没有问题;

(2)基于Java Socket实现客户端/服务器功能,传输方式用TCP;

(3)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;

(4)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;

(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;

2.实验过程:
(1)ServerOne代码(服务器端)

import java.io.*;
import java.net.*;
public class ServerOne {
    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);
        }*/
        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);
            MyDC d=new MyDC();
            System.out.println("服务器收到客户的提问:"+clear);
            int answer=d.evaluate(clear);
            out.writeUTF(answer+"");
            Thread.sleep(500);
        }
        catch(Exception e) {
            System.out.println("客户已断开"+e);
        }
    }
}

(2) ClientOne代码(客户端)

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

public class ClientOne {
    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("请输入算式:");
        Scanner scanner = new Scanner(System.in);
        String str = scanner.nextLine();//输入算式
        MyBC b = new MyBC();
        str = b.result(str);
        String secret=Encoder.AESEncode(key,str);//客户端进行加密

        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);
        }
    }
}

(3) Encoder代码(加解密代码)

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;

/*
 * AES对称加密和解密
 */
public class Encoder {
    /*
     * 加密
     * 1.构造密钥生成器
     * 2.根据ecnodeRules规则初始化密钥生成器
     * 3.产生密钥
     * 4.创建和初始化密码器
     * 5.内容加密
     * 6.返回字符串
     */
    public static String AESEncode(String encodeRules,String content){
        try {
            //1.构造密钥生成器,指定为AES算法,不区分大小写
            KeyGenerator keygen=KeyGenerator.getInstance("AES");
            //2.根据ecnodeRules规则初始化密钥生成器
            //生成一个128位的随机源,根据传入的字节数组
            keygen.init(128, new SecureRandom(encodeRules.getBytes()));
            //3.产生原始对称密钥
            SecretKey original_key=keygen.generateKey();
            //4.获得原始对称密钥的字节数组
            byte [] raw=original_key.getEncoded();
            //5.根据字节数组生成AES密钥
            SecretKey key=new SecretKeySpec(raw, "AES");
            //6.根据指定算法AES自成密码器
            Cipher cipher=Cipher.getInstance("AES");
            //7.初始化密码器,第一个参数为加密(Encrypt_mode)或者解密解密(Decrypt_mode)操作,第二个参数为使用的KEY
            cipher.init(Cipher.ENCRYPT_MODE, key);
            //8.获取加密内容的字节数组(这里要设置为utf-8)不然内容中如果有中文和英文混合中文就会解密为乱码
            byte [] byte_encode=content.getBytes("utf-8");
            //9.根据密码器的初始化方式--加密:将数据加密
            byte [] byte_AES=cipher.doFinal(byte_encode);
            //10.将加密后的数据转换为字符串
            //这里用Base64Encoder中会找不到包
            //解决办法:
            //在项目的Build path中先移除JRE System Library,再添加库JRE System Library,重新编译后就一切正常了。
            String AES_encode=new String(new BASE64Encoder().encode(byte_AES));
            //11.将字符串返回
            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();
        }

        //如果有错就返加nulll
        return null;
    }
    /*
     * 解密
     * 解密过程:
     * 1.同加密1-4步
     * 2.将加密后的字符串反纺成byte[]数组
     * 3.将加密内容解密
     */
    public static String AESDncode(String encodeRules,String content){
        try {
            //1.构造密钥生成器,指定为AES算法,不区分大小写
            KeyGenerator keygen=KeyGenerator.getInstance("AES");
            //2.根据ecnodeRules规则初始化密钥生成器
            //生成一个128位的随机源,根据传入的字节数组
            keygen.init(128, new SecureRandom(encodeRules.getBytes()));
            //3.产生原始对称密钥
            SecretKey original_key=keygen.generateKey();
            //4.获得原始对称密钥的字节数组
            byte [] raw=original_key.getEncoded();
            //5.根据字节数组生成AES密钥
            SecretKey key=new SecretKeySpec(raw, "AES");
            //6.根据指定算法AES自成密码器
            Cipher cipher=Cipher.getInstance("AES");
            //7.初始化密码器,第一个参数为加密(Encrypt_mode)或者解密(Decrypt_mode)操作,第二个参数为使用的KEY
            cipher.init(Cipher.DECRYPT_MODE, key);
            //8.将加密并编码后的内容解码成字节数组
            byte [] byte_content= new BASE64Decoder().decodeBuffer(content);
            /*
             * 解密
             */
            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();
        }

        //如果有错就返加nulll
        return null;
    }

}

(4)Skey_AES代码(AES调用代码)

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);
    }
}

注: Encoder代码和Skey_AES代码为参考网上的代码,在运行ServerOne代码和ClientOne代码前应先运行Skey_AES代码,任然需要MyDC代码与MyBC代码。

3.实验截图:
(1)服务器端截图:
技术图片

(2)客户端截图:
技术图片

4.码云链接:
https://gitee.com/zzm-zcc/zhang_zhi_min/commit/c3d15a343490157a6c1eda6e6c102c2590fa526b

四、实验五 网络编程与安全-4

1.实验要求:
密钥分发结对编程:1人负责客户端,一人负责服务器;

(1)注意责任归宿,要会通过测试证明自己没有问题;

(2)基于Java Socket实现客户端/服务器功能,传输方式用TCP;

(3)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;

(4)客户端和服务器用DH算法进行3DES或AES算法的密钥交换;

(5)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;

(6)客户端显示服务器发送过来的结果;

(7)上传测试结果截图和码云链接;

2.实验过程:
(1)Key_DH代码:

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

public class Key_DH{
    //三个静态变量的定义从
// C:\\j2sdk-1_4_0-doc\\docs\\guide\\security\\jce\\JCERefGuide.html
// 拷贝而来
// The 1024 bit Diffie-Hellman modulus values used by SKIP
    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();
        // 保存公钥
        FileOutputStream  f1=new FileOutputStream(args[0]);
        ObjectOutputStream b1=new  ObjectOutputStream(f1);
        b1.writeObject(pbk);
        // 保存私钥
        FileOutputStream  f2=new FileOutputStream(args[1]);
        ObjectOutputStream b2=new  ObjectOutputStream(f2);
        b2.writeObject(prk);
    }
}  

(2)KeyAgree代码:

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

public class KeyAgree{
    public static void main(String args[ ]) throws Exception{
        File file=new File("Sharekey.dat");
        // 读取对方的DH公钥
        FileInputStream f1=new FileInputStream("Apub.dat");
        ObjectInputStream b1=new ObjectInputStream(f1);
        PublicKey  pbk=(PublicKey)b1.readObject( );
        //读取自己的DH私钥
        FileInputStream f2=new FileInputStream("Bpri.dat");
        ObjectInputStream b2=new ObjectInputStream(f2);
        PrivateKey  prk=(PrivateKey)b2.readObject( );
        // 执行密钥协定
        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]+",");
        }
        OutputStream out=new FileOutputStream(file);
        out.write(sb);
        out.close();
        SecretKeySpec k=new  SecretKeySpec(sb,"AES");
    }
}

(3)ServerTwo代码(服务器端):

import java.io.*;
import java.net.*;
public class ServerTwo {
    public static void main(String args[]) throws  IOException{
        String sharekey="";
        int n=-1;
        byte [] a=new byte[128];
        try{  File f=new File("Sharekey.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 clear = Encoder.AESDncode(truekey,secret);//使用原密钥解密表达式
            MyDC d=new MyDC();
            int answer=d.evaluate(clear);
            out.writeUTF(answer+"");
            System.out.println("服务器提供的解密:"+clear);


            Thread.sleep(500);
        }
        catch(Exception e) {
            System.out.println("客户已断开"+e);
        }
    }
}

(4)ClientTwo代码(客户端):

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

public class ClientTwo {
    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("Sharekey.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
        MyBC b=new MyBC();
        str=b.result(str);
        String secret=Encoder.AESEncode(key1, str);//客户端对表达式进行加密
        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);
            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);
        }
    }
}

注:任然需要MyDC代码与MyBC代码和Encoder代码,在运行ServerTwo代码和ClientTwo代码前应先运行Key_DH代码、再运行KeyAgree代码、最后运行ServerTwo代码和ClientTwo代码。

3.实验截图:
(1)运行Key_DH代码的截图(需要通过命令行):
技术图片
技术图片

(2)运行KeyAgree代码的截图:
技术图片

(3)服务器端运行截图:
技术图片

(4)客户端运行截图:
技术图片

4.码云链接:
https://gitee.com/zzm-zcc/zhang_zhi_min/commit/bba1a88b5ede8025aeb19f22c4254300c2cee901

五、实验五 网络编程与安全-5

1.实验要求:
完整性校验结对编程:1人负责客户端,一人负责服务器;

(1)注意责任归宿,要会通过测试证明自己没有问题;

(2)基于Java Socket实现客户端/服务器功能,传输方式用TCP;

(3)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;

(4)客户端和服务器用DH算法进行3DES或AES算法的密钥交换;

(5)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;

(6)客户端显示服务器发送过来的结果;

(7)上传测试结果截图和码云链接;

2.实验过程:
(1)DigestPass代码:

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;
    }
}

(2)ServerThree代码(服务器端):

import java.io.*;
import java.net.*;
public class ServerThree {
    public static void main(String args[]) throws  IOException{
        String sharekey="";
        int n=-1;
        byte [] a=new byte[128];
        try{  File f=new File("Sharekey.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
            MyDC d=new MyDC();
            int answer=d.evaluate(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);
        }
    }
}

(3)ClientThree代码(客户端):

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

public class ClientThree {
    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("Sharekey.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
        MyBC b=new MyBC();
        str=b.result(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);
        }
    }
}

注:任然需要MyDC代码、MyBC代码、Encoder代码、Key_DH代码和KeyAgree代码,在运行ServerThree代码和ClientThree代码前应先运行Key_DH代码(与实验五 网络编程与安全-4中相同)、再运行KeyAgree代码、最后运行ServerThree代码和ClientThree代码。

3.实验截图:
(1)服务器端截图:
技术图片

(2)客户端截图:
技术图片

4.码云链接:
https://gitee.com/zzm-zcc/zhang_zhi_min/commit/33995dbe0838b1eebdceff7f6bb1b8a6b86e3922

六、实验感想:

通过此次实验,充分了解了各种加密算法的结构与思想,也加深了密码学的部分知识,拓展了知识面。

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