20175212童皓楨 實驗五 網絡編程與安全

20175212童皓楨 實驗五 網絡編程與安全

實驗內容

  • 結對編程,完成網絡編程與安全相關內容html

    實驗步驟

    任務一

    任務一要求:
  1. 結對實現中綴表達式轉後綴表達式的功能 MyBC.java
  2. 結對實現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
    實驗過程:
    由中綴式求得後綴式能夠使用棧,僞代碼以下:
-   設立一個棧,存放運算符,首先棧爲空;
-   從左到右掃描中綴式,若遇到操做數,直接輸出,並輸出一個空格做爲兩個操做數的分隔符;
-   若遇到運算符,則與棧頂比較,比棧頂級別高則進棧,不然退出棧頂元素並輸出,而後輸出一個空格做分隔符;
-   若遇到左括號,進棧;若遇到右括號,則一直退棧輸出,直到退到左括號止。
-   當棧變成空時,輸出的結果即爲後綴表達式
後綴表達式求值僞代碼以下:
-   設置一個操做數棧,開始棧爲空;
-   從左到右遍歷後綴表達式,遇操做數,進棧;
-   若遇運算符,則從棧中退出兩個元素,先退出的放到運算符的右邊,後退出的放到運算符左邊,運算後的結果再進棧,直到後綴表達式遍歷完畢。
-   重複以上步驟,直至後綴表達式結束,棧中最後一個數字就是表達式的值。

實驗代碼:java

  • MyDC
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 '-':
                    getOp(ch, 1);
                    break;
                case '*':
                case '/':
                    getOp(ch, 2);
                    break;
                case '(':
                    theStack.push(ch);
                    break;
                case ')':
                    getParen(ch);
                    break;
                default:
                    output = output + ch;
                    break;
            }
        }
        while (!theStack.isEmpty()) {
            output = output + theStack.pop();
        }
        return output;
    }

    public void getOp(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 getParen(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);
        }
    }
}
  • 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 str)
    {
        int op1, op2, result = 0;
        String token;
        StringTokenizer tokenizer = new StringTokenizer (str);

        while (tokenizer.hasMoreTokens())
        {
            token = tokenizer.nextToken();

            //若是是運算符,調用isOperator
            if (isOperator(token)) {
                //從棧中彈出操做數2
                op2 = stack.pop();
                //從棧中彈出操做數1
                op1 = stack.pop();
                //根據運算符和兩個操做數調用evalSingleOp計算result;
                result=evalSingleOp(token.charAt(0), op1, op2);
                //計算result入棧;
                stack.push(result);
            } else//若是是操做數
                //操做數入棧;
                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;
    }
}
  • MyBCTest
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 str)
    {
        int op1, op2, result = 0;
        String token;
        StringTokenizer tokenizer = new StringTokenizer (str);

        while (tokenizer.hasMoreTokens())
        {
            token = tokenizer.nextToken();

            //若是是運算符,調用isOperator
            if (isOperator(token)) {
                //從棧中彈出操做數2
                op2 = stack.pop();
                //從棧中彈出操做數1
                op1 = stack.pop();
                //根據運算符和兩個操做數調用evalSingleOp計算result;
                result=evalSingleOp(token.charAt(0), op1, op2);
                //計算result入棧;
                stack.push(result);
            } else//若是是操做數
                //操做數入棧;
                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;
    }
}

運行結果:
輸入圖片說明算法

任務二

任務二要求:express

1人負責客戶端,一人負責服務器編程

  1. 注意責任歸宿,要會經過測試證實本身沒有問題
  2. 基於Java Socket實現客戶端/服務器功能,傳輸方式用TCP
  3. 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,把後綴表達式經過網絡發送給服務器
  4. 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的值,把結果發送給客戶端
  5. 客戶端顯示服務器發送過來的結果- 提交代碼運行截圖和碼雲Git連接

實驗過程數組

  • java.net.Socket:安全

  • 套接字是一個網絡鏈接的端點。在java中,使用java.net.Socket對象來表示一個套接字。
  • 要建立一個套接字,能夠使用Socket的構造方法,如:public Socket(java.lang.String host, int port)。其中,host是遠程機器名或IP地址,port是遠程應用程序的端口號。
  • 一旦成功建立了Socket類的一個實例,就能夠使用它發送或接收字節流。要發送字節流,必須先調用Socket類的getOutputStream方法來獲取一個java.io.OutputStream對象。要向遠程應用程序發送文本,一般要從返回的OutputStream對象構建一個java.io.PrintWriter對象。要接收來自鏈接的另外一端的字節流,能夠調用Socket類的getInputStream方法,它返回一個java.io.InputStream。
    『java.net.ServerSocket』:
  • ServerSocket是服務器套接字的一個實現。ServerSocket和Socket不一樣,服務器套接字的角色是,等待來自客戶端的鏈接請求。一旦服務器套接字得到了一個鏈接請求,它就會建立一個Socket實例,以處理和客戶端的通訊。服務器

  • Address網絡

import java.net.*;

public class Address {

    public static void main(String[] args) throws UnknownHostException {

        InetAddress net = InetAddress.getLocalHost();

        System.out.println(net.toString());

    }

}
  • Client
import java.io.*;
import java.net.*;

public class Client {
    public static void main(String args[]) {
        System.out.println("客戶端啓動...");
        //while (true) {
        Socket mysocket;
        DataInputStream in = null;
        DataOutputStream out = null;
        try {
            mysocket = new Socket("192.168.56.1", 2019);
            in = new DataInputStream(mysocket.getInputStream());
            out = new DataOutputStream(mysocket.getOutputStream());
            System.out.println("請輸入:");
            String str = new BufferedReader(new InputStreamReader(System.in)).readLine();

            MyBC turner = new MyBC(str);
            String infix;
            infix=turner.doTrans();
            StringBuilder newInfix = new StringBuilder(infix.replace(" ",""));
            for (int i = 1; i < infix.length()+(i+1)/2 ; i=i+2) {
                newInfix.insert(i," ");
            }
            out.writeUTF(newInfix.toString());//調用toString()方法,返回newInflx的String值,以便調用writeUTF方法

            String s = in.readUTF();   //in讀取信息,堵塞狀態
            System.out.println("客戶收到服務器的回答:" + s);
            Thread.sleep(500);//在500毫秒數讓當前正在執行的線程休眠
        } catch (Exception e) {
            System.out.println("服務器已斷開" + e);
        }
        //}
    }
}
  • Server
import java.io.*;
import java.net.*;

public class Server {
    public static void main(String[] args) throws IOException {
        int answer;
        //while (true) {
        ServerSocket serverForClient = null;
        Socket socketOnServer = null;
        DataOutputStream out = null;
        DataInputStream in = null;
        try {
            serverForClient = new ServerSocket(2019);
        } catch (IOException e1) {
            System.out.println(e1);
        }
        try {
            System.out.println("等待客戶呼叫");
            socketOnServer = serverForClient.accept(); //堵塞狀態,除非有客戶呼叫
            out = new DataOutputStream(socketOnServer.getOutputStream());
            in = new DataInputStream(socketOnServer.getInputStream());
            String s = in.readUTF(); // in讀取信息,堵塞狀態
            System.out.println("服務器收到客戶的提問:" + s);
            MyDC myDC = new MyDC();
            answer = myDC.evaluate(s);
            out.writeUTF(answer + "");
            Thread.sleep(500);
        } catch (Exception e) {
            System.out.println("客戶已斷開" + e);
        }
        //}
    }
}

運行結果:
輸入圖片說明
輸入圖片說明app

任務三

任務三要求:

1人負責客戶端,一人負責服務器

  1. 注意責任歸宿,要會經過測試證實本身沒有問題
  2. 基於Java Socket實現客戶端/服務器功能,傳輸方式用TCP
  3. 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
  4. 服務器接收到後綴表達式表達式後,進行解密(和客戶端協商密鑰,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
  5. 客戶端顯示服務器發送過來的結果
  • Client.java
import javax.crypto.Cipher;
import java.io.*;
import java.net.*;
import java.security.Key;

public class Client {
    public static void main(String args[]) {
        System.out.println("客戶端啓動...");
        //while (true) {
        Socket mysocket;
        DataInputStream in = null;
        DataOutputStream out = null;
        try {
            mysocket = new Socket("192.168.56.1", 2019);
            in = new DataInputStream(mysocket.getInputStream());
            out = new DataOutputStream(mysocket.getOutputStream());
            System.out.println("請輸入:");
            String str = new BufferedReader(new InputStreamReader(System.in)).readLine();

            MyBC turner = new MyBC(str);
            String infix;
            infix=turner.doTrans();
            StringBuilder newInfix = new StringBuilder(infix.replace(" ",""));
            for (int i = 1; i < infix.length()+(i+1)/2 ; i=i+2) {
                newInfix.insert(i," ");
            }

            String str1=newInfix.toString();//DES加密
            String a=null;
            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[]=str1.getBytes("UTF8");
            byte ctext[]=cp.doFinal(ptext);
            for(int i=0;i<ctext.length;i++){
                a+=String.valueOf(ctext[i]);
            }
            FileOutputStream f2=new FileOutputStream("SEnc.dat");
            f2.write(ctext);

            out.writeUTF(a);//調用toString()方法,返回newInflx的String值,以便調用writeUTF方法
            String s = in.readUTF();   //in讀取信息,堵塞狀態
            System.out.println("客戶收到服務器的回答:" + s);
            Thread.sleep(500);//在500毫秒數讓當前正在執行的線程休眠
        } catch (Exception e) {
            System.out.println("服務器已斷開" + e);
        }
        //}
    }
}
  • Server.java
import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;
import java.io.*;
import java.net.*;

public class Server {
    public static void main(String[] args) throws IOException {
        int answer;
        //while (true) {
        ServerSocket serverForClient = null;
        Socket socketOnServer = null;
        DataOutputStream out = null;
        DataInputStream in = null;
        try {
            serverForClient = new ServerSocket(2019);
        } catch (IOException e1) {
            System.out.println(e1);
        }
        try {
            System.out.println("等待客戶呼叫");
            socketOnServer = serverForClient.accept(); //堵塞狀態,除非有客戶呼叫
            out = new DataOutputStream(socketOnServer.getOutputStream());
            in = new DataInputStream(socketOnServer.getInputStream());
            String s = in.readUTF(); // in讀取信息,堵塞狀態

            // 獲取密文
            FileInputStream f=new FileInputStream("SEnc.dat");
            int num=f.available();
            byte[ ] ctext=new byte[num];
            f.read(ctext);
            // 獲取密鑰
            FileInputStream  f2=new FileInputStream("keykb1.dat");
            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);
            // 顯示明文
            String p=new String(ptext,"UTF8");

            System.out.println("服務器收到客戶的提問:" + p);
            MyDC myDC = new MyDC();
            answer = myDC.evaluate(p);
            out.writeUTF(answer + "");
            Thread.sleep(500);
        } catch (Exception e) {
            System.out.println("客戶已斷開" + e);
        }
        //}
    }
}
  • Skey_DES.java
import java.io.*;
import javax.crypto.*;
public class Skey_DES{
    public static void main(String args[])
            throws Exception{
        KeyGenerator kg=KeyGenerator.getInstance("DESede");
        kg.init(168);
        SecretKey k=kg.generateKey( );
        FileOutputStream  f=new FileOutputStream("key1.dat");
        ObjectOutputStream b=new  ObjectOutputStream(f);
        b.writeObject(k);
    }
}
  • Skey_kb.java
import java.io.*;
import java.security.*;
public class Skey_kb{
    public static void main(String args[]) throws Exception{
        FileInputStream f=new FileInputStream("key1.dat");
        ObjectInputStream b=new ObjectInputStream(f);
        Key k=(Key)b.readObject( );
        byte[ ] kb=k.getEncoded( );
        FileOutputStream  f2=new FileOutputStream("keykb1.dat");
        f2.write(kb);
        // 打印密鑰編碼中的內容
        for(int i=0;i<kb.length;i++){
            System.out.print(kb[i]+",");
        }
    }
}

運行結果:
輸入圖片說明
輸入圖片說明

任務四

任務四要求:

1人負責客戶端,一人負責服務器

  1. 注意責任歸宿,要會經過測試證實本身沒有問題
  2. 基於Java Socket實現客戶端/服務器功能,傳輸方式用TCP
  3. 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算法加密經過網絡把密文發送給服務器
  4. 客戶端和服務器用DH算法進行3DES或AES算法的密鑰交換
  5. 服務器接收到後綴表達式表達式後,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
  6. 客戶端顯示服務器發送過來的結果
  • Client
import java.net.*;
import java.io.*;
import java.security.*;
import javax.crypto.*;
import javax.crypto.spec.*;
public class Client {
    public static void main(String []args) throws Exception
    {
        try
        {
            // 一、建立客戶端Socket,指定服務器地址和端口
            Socket socket=new Socket("192.168.56.1",2019);

            System.out.println("客戶端成功啓動,等待客戶端呼叫");
            // 二、獲取輸出流,向服務器端發送信息
            // 向本機的10001端口發出客戶請求
            System.out.println("請輸入中綴表達式:");
            BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
            // 由系統標準輸入設備構造BufferedReader對象
            PrintWriter write = new PrintWriter(socket.getOutputStream());
            // 由Socket對象獲得輸出流,並構造PrintWriter對象
            //三、獲取輸入流,並讀取服務器端的響應信息
            BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
            // 由Socket對象獲得輸入流,並構造相應的BufferedReader對象
            String readline, infix, expression;
            readline = br.readLine(); // 從系統標準輸入讀入一字符串

            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("後綴表達式: " + newInfix);
            expression=newInfix.toString();

            // 讀取對方的DH公鑰
            FileInputStream f1=new FileInputStream("Bpub");
            ObjectInputStream b1=new ObjectInputStream(f1);
            PublicKey  pbk=(PublicKey)b1.readObject( );
            //讀取本身的DH私鑰
            FileInputStream f2=new FileInputStream("Asec");
            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();
            //System.out.println(sb.length);
            byte[]ssb=new byte[24];
            for(int i=0;i<24;i++)
                ssb[i]=sb[i];
            Key k=new SecretKeySpec(ssb,"DESede");
            Cipher cp=Cipher.getInstance("DESede");
            cp.init(Cipher.ENCRYPT_MODE, k);
            byte ptext[]=expression.getBytes("UTF-8");
            byte ctext[]=cp.doFinal(ptext);
            String Str=new String(ctext,"ISO-8859-1");


            while (!readline.equals("end")) {
                // 若從標準輸入讀入的字符串爲 "end"則中止循環
                write.println(Str);
                // 將從系統標準輸入讀入的字符串輸出到Server
                write.flush();
                // 刷新輸出流,使Server立刻收到該字符串
                System.out.println("加密後的信息:" + Str);
                // 在系統標準輸出上打印讀入的字符串
                System.out.println("服務器發來的信息:" + in.readLine());
                // 從Server讀入一字符串,並打印到標準輸出上
                readline = br.readLine(); // 從系統標準輸入讀入一字符串
            } // 繼續循環
            //四、關閉資源
            write.close(); // 關閉Socket輸出流
            in.close(); // 關閉Socket輸入流
            socket.close(); // 關閉Socket
        }
        catch (Exception e)
        {
            System.out.println(e);//輸出異常
        }
        finally
        {

        }

    }
}
  • Serve
import java.net.*;
import java.io.*;
import java.security.*;
import javax.crypto.*;
import javax.crypto.spec.*;
public class Server{
    public static void main(String []args) throws Exception
    {
        ServerSocket sc = null;
        Socket socket=null;
        try
        {
            MyDC evaluator = new MyDC();

            sc= new ServerSocket(2019);//建立服務器套接字
            //System.out.println("端口號:" + sc.getLocalPort());
            System.out.println("服務器成功啓動,等待客戶端應答");
            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);
            //使用服務器端RSA的私鑰對DES的密鑰進行解密
            String aline2=in.readLine();
            System.out.println("客戶端發來的信息爲:"+aline2);


            // 獲取密鑰
            byte[]ctext=aline2.getBytes("ISO-8859-1");
            // 讀取對方的DH公鑰
            FileInputStream f1=new FileInputStream("Bpub");
            ObjectInputStream b1=new ObjectInputStream(f1);
            PublicKey  pbk=(PublicKey)b1.readObject( );
            //讀取本身的DH私鑰
            FileInputStream f2=new FileInputStream("Asec");
            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();
            byte[]ssb=new byte[24];
            for(int i=0;i<24;i++)
                ssb[i]=sb[i];
            SecretKeySpec k=new  SecretKeySpec(ssb,"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 ans = evaluator.evaluate(p);
            out.println(ans);
            System.out.println("Result = "+ans);

        } catch (Exception e) {
            System.out.println(e);
        }
    }

    //十六進制和十進制轉換
    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;
    }
}
  • KeyAgree
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 KeyAgree{
    public static void main(String args[ ]) throws Exception{
        // 讀取對方的DH公鑰
        FileInputStream f1=new FileInputStream("Bpub");
        ObjectInputStream b1=new ObjectInputStream(f1);
        PublicKey  pbk=(PublicKey)b1.readObject( );
//讀取本身的DH私鑰
        FileInputStream f2=new FileInputStream("Asec");
        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");
    }
}
  • Key_DH.java
import java.io.*;
import java.math.*;
import java.security.*;
import java.security.spec.*;
import javax.crypto.*;
import javax.crypto.spec.*;
import javax.crypto.interfaces.*;

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{
    //三個靜態變量的定義從
// C:\j2sdk-1_4_0-doc\docs\guide\security\jce\JCERefGuide.html
// 拷貝而來
// 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();
        // 保存公鑰
        FileOutputStream  f1=new FileOutputStream("Bpub");
        ObjectOutputStream b1=new  ObjectOutputStream(f1);
        b1.writeObject(pbk);
        // 保存私鑰
        FileOutputStream  f2=new FileOutputStream("Asec");
        ObjectOutputStream b2=new  ObjectOutputStream(f2);
        b2.writeObject(prk);
    }
}

運行結果:
輸入圖片說明
輸入圖片說明

任務五

完整性校驗結對編程:

1人負責客戶端,一人負責服務器

  1. 注意責任歸宿,要會經過測試證實本身沒有問題
  2. 基於Java Socket實現客戶端/服務器功能,傳輸方式用TCP
  3. 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算法加密經過網絡把密文和明文的MD5値發送給服務器
  4. 客戶端和服務器用DH算法進行3DES或AES算法的密鑰交換
  5. 服務器接收到後綴表達式表達式後,進行解密,解密後計算明文的MD5值,和客戶端傳來的MD5進行比較,一致則調用MyDC.java的功能計算後綴表達式的值,把結果發送給客戶端
  6. 客戶端顯示服務器發送過來的結果
  7. 上傳測試結果截圖和碼雲連接
  • Serve
import java.net.*;
import java.io.*;
import java.security.*;
import javax.crypto.*;
import javax.crypto.spec.*;
import java.security.interfaces.*;
import java.math.*;

public class Server {
    public static void main(String args[]) throws Exception {
        ServerSocket link = null;
        Socket socket = null;
        try {
            link = new ServerSocket(3);// 建立服務器套接字
            //System.out.println("端口號:" + link.getLocalPort());
            System.out.println("等待客戶鏈接");
            socket = link.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);
            // 使用服務器端RSA的私鑰對DES的密鑰進行解密

            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
            // 使用Hash函數檢測明文完整性
            String aline3 = in.readLine();
            String x = p;
            MessageDigest m2 = MessageDigest.getInstance("MD5");//使用MD5算法返回實現指定摘要算法的 MessageDigest對象
            m2.update(x.getBytes());
            byte a[] = m2.digest();
            String result = "";
            for (int i = 0; i < a.length; i++) {
                result += Integer.toHexString((0x000000ff & a[i]) | 0xffffff00).substring(6);
            }
            System.out.println("MD5:"+result);
            if (aline3.equals(result)) {
                System.out.println("匹配成功");
            }
            MyDC evaluator = new MyDC();
            int _result = evaluator.value(p);
            out.println(_result);
            out.close();
            in.close();
            link.close();
        } catch (Exception e) {
            System.out.println(e);
        }
    }
    //二進制轉換成十六進制,防止byte[]數字轉換成string類型時形成的數據損失
    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());//將字符串中的小寫字母轉換成大寫字母,而後加在字符串上
        }
        return sb.toString();
    }
    //將十六進制轉換爲二進制
    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;
    }

}

Client

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

public class Client {
    public static void main(String args[]) throws Exception {
        try {
            KeyGenerator kg = KeyGenerator.getInstance("DESede");
            kg.init(168);
            SecretKey k = kg.generateKey();
            byte[] ptext2 = k.getEncoded();
            Socket socket = new Socket("127.0.0.1", 3);
            System.out.println("客戶端成功啓動,等待客戶端呼叫");
            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.println("請輸入中綴表達式:");
            //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

            // 將客戶端明文的Hash值傳送給服務器
            String x = postfix;
            MessageDigest m2 = MessageDigest.getInstance("MD5");
            m2.update(x.getBytes());
            byte a[] = m2.digest();
            String result = "";
            for (int i = 0; i < a.length; i++) {
                result += Integer.toHexString((0x000000ff & a[i]) | 0xffffff00).substring(6);
            }
            System.out.println("MD5:"+result);
            out.println(result);//經過網絡將明文的Hash函數值傳送到服務器
            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);//輸出異常
        } finally {
        }

    }

    //將十六進制轉換成二進制
    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();
    }
}

運行結果:
輸入圖片說明
輸入圖片說明

實驗中遇到的問題

問題一:輸入表達算式時提示斷開鏈接
輸入圖片說明
解決辦法:輸入表達式時一鼓作氣,而不能像日常同樣對已輸入的括號內的內容進行修改

參考博客

http://www.javashuo.com/article/p-hnfnmcqg-eo.html
http://www.cnblogs.com/rocedu/p/6766748.html#SECDSA

結對夥伴及博客連接

20175227

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