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
實驗步驟
任務一
任務一要求：
結對實現中綴表達式轉后綴表達式的功能 MyBC.java結對實現從上面功能中獲取的表達式中實現后綴表達式求值的功能,調用MyDC.java
實驗過程：
由中綴式求得后綴式可以使用棧，偽代碼如下： - 設立一個棧，存放運算符，首先棧為空；
- 從左到右掃描中綴式，若遇到操作數，直接輸出，并輸出一個空格作為兩個操作數的分隔符；
- 若遇到運算符，則與棧頂比較，比棧頂級別高則進棧，否則退出棧頂元素并輸出，然后輸出一個空格作分隔符；
- 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，輸出的結果即為后綴表達式
后綴表達式求值偽代碼如下：
- 設置一個操作數棧，開始棧為空；
- 從左到右遍歷后綴表達式，遇操作數，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，后退出的放到運算符左邊，運算后的結果再進棧，直到后綴表達式遍歷完畢。
- 重復以上步驟，直至后綴表達式結束，棧中最后一個數字就是表達式的值。
實驗代碼：
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;elseprec2 = 2;if (prec2 < prec1) {theStack.push(opTop);break;} elseoutput = output + opTop;}}theStack.push(opThis);}public void getParen(char ch) {while (!theStack.isEmpty()) {char chx = theStack.pop();if (chx == '(')break;elseoutput = 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);}}
}
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();//如果是運算符，調用isOperatorif (isOperator(token)) {//從棧中彈出操作數2op2 = stack.pop();//從棧中彈出操作數1op1 = stack.pop();//根據運算符和兩個操作數調用evalSingleOp計算result;result=evalSingleOp(token.charAt(0), op1, op2);//計算result入棧;stack.push(result);} else//如果是操作數//操作數入棧;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;}
}
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();//如果是運算符，調用isOperatorif (isOperator(token)) {//從棧中彈出操作數2op2 = stack.pop();//從棧中彈出操作數1op1 = stack.pop();//根據運算符和兩個操作數調用evalSingleOp計算result;result=evalSingleOp(token.charAt(0), op1, op2);//計算result入棧;stack.push(result);} else//如果是操作數//操作數入棧;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：
任務二
任務二要求：
1人負責客戶端，一人負責服務器
注意責任歸宿，要會通過測試證明自己沒有問題基于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，然后把中綴表達式調用MyBC.java的功能轉化為后綴表達式，把后綴表達式通過網絡發送給服務器服務器接收到后綴表達式，調用MyDC.java的功能計算后綴表達式的值，把結果發送給客戶端客戶端顯示服務器發送過來的結果- 提交代碼運行截圖和碼云Git鏈接 實驗過程
import java.net.*;public class Address {public static void main(String[] args) throws UnknownHostException {InetAddress net = InetAddress.getLocalHost();System.out.println(net.toString());}}
import java.io.*;
import java.net.*;public class Client {public static void main(String args[]) {System.out.println("客戶端啟動...");//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);}//}}
}
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：
任務三
任務三要求：
1人負責客戶端，一人負責服務器
注意責任歸宿，要會通過測試證明自己沒有問題基于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，然后把中綴表達式調用MyBC.java的功能轉化為后綴表達式，把后綴表達式用3DES或AES算法加密后通過網絡把密文發送給服務器服務器接收到后綴表達式表達式后，進行解密（和客戶端協商密鑰，可以用數組保存），然后調用MyDC.java的功能計算后綴表達式的值，把結果發送給客戶端客戶端顯示服務器發送過來的結果 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("客戶端啟動...");//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);}//}}
}
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);}//}}
}
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);}
}
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：
任務四
任務四要求：
1人負責客戶端，一人負責服務器
注意責任歸宿，要會通過測試證明自己沒有問題基于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，然后把中綴表達式調用MyBC.java的功能轉化為后綴表達式，把后綴表達式用3DES或AES算法加密通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算法的密鑰交換服務器接收到后綴表達式表達式后，進行解密，然后調用MyDC.java的功能計算后綴表達式的值，把結果發送給客戶端客戶端顯示服務器發送過來的結果 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{// 1、創建客戶端Socket，指定服務器地址和端口Socket socket=new Socket("192.168.56.1",2019);System.out.println("客戶端成功啟動，等待客戶端呼叫");// 2、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對象得到輸出流，并構造PrintWriter對象//3、獲取輸入流，并讀取服務器端的響應信息BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));// 由Socket對象得到輸入流，并構造相應的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("后綴表達式： " + 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( );//讀取自己的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為 "end"則停止循環write.println(Str);// 將從系統標準輸入讀入的字符串輸出到Serverwrite.flush();// 刷新輸出流，使Server馬上收到該字符串System.out.println("加密后的信息:" + 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，并打印到標準輸出上readline = br.readLine(); // 從系統標準輸入讀入一字符串} // 繼續循環//4、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{}}
}
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);//創建服務器套接字//System.out.println("端口號:" + sc.getLocalPort());System.out.println("服務器成功啟動，等待客戶端應答");socket = sc.accept(); //等待客戶端連接System.out.println("已經建立連接");//獲得網絡輸入流對象的引用BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));//獲得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("客戶端發來的信息為："+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( );//讀取自己的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;}
}
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( );
//讀取自己的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");}
}
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 SKIPprivate 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 modulusprivate static final BigInteger skip1024Modulus= new BigInteger(1, skip1024ModulusBytes);// The base used with the SKIP 1024 bit modulusprivate 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：
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
注意責任歸宿，要會通過測試證明自己沒有問題基于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，然后把中綴表達式調用MyBC.java的功能轉化為后綴表達式，把后綴表達式用3DES或AES算法加密通過網絡把密文和明文的MD5値發送給服務器客戶端和服務器用DH算法進行3DES或AES算法的密鑰交換服務器接收到后綴表達式表達式后，進行解密，解密后計算明文的MD5值，和客戶端傳來的MD5進行比較，一致則調用MyDC.java的功能計算后綴表達式的值，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云鏈接 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);// 創建服務器套接字//System.out.println("端口號:" + link.getLocalPort());System.out.println("等待客戶連接");socket = link.accept(); // 等待客戶端連接System.out.println("已經建立連接");//獲得網絡輸入流對象的引用BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));//獲得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 nBigInteger 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為：" + 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類型時造成的數據損失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,然后加在字符串上}return sb.toString();}//將十六進制轉換為二進制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("客戶端成功啟動，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); // 通過網絡將加密后的秘鑰傳送到服務器System.out.println("請輸入中綴表達式：");//用DES加密明文得到密文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); // 通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);//通過網絡將明文的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為：" + 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：
實驗中遇到的問題
問題一：輸入表達算式時提示斷開連接
解決辦法：輸入表達式時一氣呵成，而不能像平常一樣對已輸入的括號內的內容進行修改
參考博客
https://www.cnblogs.com/zxy20175227/p/10923041.html
http://www.cnblogs.com/rocedu/p/6766748.html#SECDSA
結對伙伴及博客鏈接
20175227
轉載于:https://www.cnblogs.com/thz666/p/10945796.html
總結
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