标签：jpg menu 客户 cas byte read 顺序 通过 ack
任务一:
实验过程
ab+cde+**，改为中缀表达式其实是(a+b)*((d+e)*c)实验代码：
MyBC:
import java.util.*;
import java.lang.String;
public class MyBC {
private int priority(char c){
if(c == ‘*‘ || c== ‘/‘)
return 2;
else if(c == ‘+‘ || c== ‘-‘)
return 1;
else
return 0;
}
private boolean leftPirority(Character c1,char c2){
if(c1 == null)
return false;
return priority(c1)>=priority(c2);
}
private boolean isNumber(char c){
if(‘0‘ <= c && c<=‘9‘)
return true;
return false;
}
private boolean isLeftBracket(char c){
if(c == ‘(‘)
return true;
return false;
}
private boolean isRightBracket(char c){
if(c == ‘)‘)
return true;
return false;
}
private boolean isOperator(char c){
if(c == ‘+‘ || c == ‘-‘ || c == ‘*‘ ||c == ‘/‘)
return true;
return false;
}
public String parse(String str){
class Stack<S>{
private LinkedList<S> list = new LinkedList<S>();
public void push(S t){
list.addLast(t);
}
public S pop(){
return list.removeLast();
}
public S top(){
return list.peekLast();
}
public boolean isEmpty(){
return list.isEmpty();
}
}
Stack<Character> stack = new Stack<>();
StringBuilder string = new StringBuilder();
char[] cs = str.toCharArray();
for(int i=0; i<cs.length; ++i){
char c = cs[i];
if( isNumber(c)){
string.append(c);
}else if( isLeftBracket(c)){
stack.push(c);
}else if( isOperator(c)){
while( leftPirority(stack.top(), c)){
string.append( stack.pop());
}
stack.push(c);
}else if( isRightBracket(c)){
while( !isLeftBracket( stack.top())){
string.append(stack.pop());
}
stack.pop();
}
}
while( !stack.isEmpty()){
string.append(stack.pop());
}
return string.toString();
}
}
MyDC:
import java.util.StringTokenizer;
import java.util.Stack;
public class MyDC {
/**
* constant for addition symbol
*/
private final char ADD = ‘+‘;
/**
* constant for subtraction symbol
*/
private final char SUBTRACT = ‘-‘;
/**
* constant for multiplication symbol
*/
private final char MULTIPLY = ‘*‘;
/**
* constant for division symbol
*/
private final char DIVIDE = ‘/‘;
/**
* the stack
*/
private Stack<Integer> stack;
public MyDC() {
stack = new Stack<Integer>();
}
public int evaluate(String expr) {
int op1, op2, result = 0;
String token;
StringTokenizer tokenizer = new StringTokenizer(expr);
while (tokenizer.hasMoreTokens()) {
token = tokenizer.nextToken();
if (isOperator(token)) {
op2 = (stack.pop()).intValue();
op1 = (stack.pop()).intValue();
result = evalSingleOp(token.charAt(0), op1, op2);
stack.push(new Integer(result));
} else
stack.push(new Integer(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;
}
}
MyBCTester:
import java.util.Scanner;
import java.lang.String;
public class MyBCTester {
public static void main (String[] args) {
String expression, again;
String result_1;
int result_2;
try
{
Scanner in = new Scanner(System.in);
do
{
MyBC bc = new MyBC();
System.out.println ("请输入一个中缀表达式： ");
expression = in.nextLine();
result_1 = bc.parse(expression);
System.out.println();
String[] b = result_1.split("");
String x = "";
for(int i=0;i<b.length;i++){
x=x+b[i]+" ";
}
System.out.println("后缀表达式为： " + x);
MyDC dc = new MyDC();
result_2 = dc.evaluate (x);
System.out.println ("That expression equals " + result_2);
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");
}
}
}
实验截图:
任务二：
实验代码:
//import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.view.Menu;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.widget.TextView;
public class MainActivity extends Activity implements
OnTouchListener {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
TextView tv = (TextView) findViewById(R.id.textView1);
tv.setOnTouchListener(this);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it
// is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
@Override
public boolean onTouch(View arg0, MotionEvent event) {
Intent intent = new Intent(this, ThirdActivity.class);
intent.putExtra("message", "20175208Fenix");
startActivity(intent);
return true;
}
}
实验截图：
任务三：
实验代码：
import javax.crypto.Cipher;
import java.io.*;
import java.net.Socket;
import java.security.Key;
import java.util.Scanner;
public class Client3 {
public static void main(String args[]) {
Socket mysocket;
MyBC mybc = new MyBC();
DataInputStream in = null;
DataOutputStream out = null;
Scanner scanner = new Scanner(System.in);
String str;
try {
mysocket = new Socket("192.168.188.1", 5208);
in = new DataInputStream(mysocket.getInputStream());
out = new DataOutputStream(mysocket.getOutputStream());
System.out.println("客户端启动...");
FileInputStream f = new FileInputStream("key1.dat");
ObjectInputStream b = new ObjectInputStream(f);
Key key = (Key) b.readObject();
Cipher cp = Cipher.getInstance("DESede");
cp.init(Cipher.ENCRYPT_MODE, key);
System.out.println("请输入中缀表达式：");
str = scanner.nextLine();
mybc.conversion(str);
String str1 = mybc.getMessage();
byte ptext[] = str1.getBytes("UTF-8");
byte ctext[] = cp.doFinal(ptext);
System.out.println("被加密的后缀表达式：");
for (int i = 0; i < ctext.length; i++) {
System.out.print(ctext[i] + ",");
}
System.out.println("");
out.writeUTF(ctext.length + "");
for (int i = 0; i < ctext.length; i++) {
out.writeUTF(ctext[i] + "");
//System.out.print();
}
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应:" + s);
} catch (Exception e) {
System.out.println("服务器已断开" + e);
}
}
}
import java.io.*;
import javax.crypto.*;
import javax.crypto.spec.*;
public class SDec {
public static String decipher(String s) throws Exception {
// 获取密文
FileInputStream f = new FileInputStream("SEnc.dat");
int num = f.available();
byte[] ctext = new byte[num];
f.read(ctext);
// 获取密钥
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);
// 显示明文
String p = new String(ptext, "UTF8");
System.out.println(p);
return p;
}
}
import javax.crypto.Cipher;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.ObjectInputStream;
import java.security.Key;
public class SEnc {
public String Cipher(String s) throws Exception {
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[] = s.getBytes("UTF8");
System.out.println("密文为：");
for (int i = 0; i < ptext.length; i++) {
System.out.print(ptext[i] + ",");
}
System.out.println("");
byte ctext[] = cp.doFinal(ptext);
String cipher = "";
for (int i = 0; i < ctext.length; i++) {
cipher = cipher + ctext[i];
}
FileOutputStream f2 = new FileOutputStream("SEnc.dat");
f2.write(ctext);
return cipher;
}
}
import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;
import java.io.*;
import java.net.ServerSocket;
import java.net.Socket;
public class Server3 {
public static void main(String args[]) {
MyDC mydc = new MyDC();
ServerSocket serverForClient = null;
Socket socketOnServer = null;
DataOutputStream out = null;
DataInputStream in = null;
try {
serverForClient = new ServerSocket(5208);
} catch (IOException e1) {
System.out.println(e1);
}
try {
System.out.println("等待客户呼叫");
socketOnServer = serverForClient.accept(); //堵塞状态，除非有客户呼叫
System.out.println("客户已连接");
out = new DataOutputStream(socketOnServer.getOutputStream());
in = new DataInputStream(socketOnServer.getInputStream());
String leng = in.readUTF(); // in读取信息，堵塞状态
byte ctext[] = new byte[Integer.parseInt(leng)];
for (int i = 0;i<Integer.parseInt(leng);i++) {
String temp = in.readUTF();
ctext[i] = Byte.parseByte(temp);
}
// 获取密钥
FileInputStream f2 = new FileInputStream("keykb1.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);
/*for (int i = 0; i < ptext.length; i++) {
System.out.print(ptext[i] + ",");
}
*/
System.out.println("");
// 显示明文
String p = new String(ptext,"UTF8");
System.out.println("被解密的后缀表达式：" + p);
System.out.println("计算后缀表达式" + p);
out.writeUTF(mydc.evaluate(p)+"");
} catch (Exception e) {
System.out.println("客户已断开" + e);
}
}
}
实验截图：
任务四：
import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
import java.io.*;
import java.net.Socket;
import java.security.Key;
import java.util.Optional;
import java.util.Scanner;
public class Client4 {
public static void main(String args[]) {
MyBC mybc = new MyBC();
Socket mysocket;
DataInputStream in = null;
DataOutputStream out = null;
Scanner scanner = new Scanner(System.in);
String str;
try {
mysocket = new Socket("192.168.188.1", 5208);
System.out.println("客户端启动...");
in = new DataInputStream(mysocket.getInputStream());
out = new DataOutputStream(mysocket.getOutputStream());
System.out.println("请输入中缀表达式：");
str = scanner.nextLine();
Key_DH.DH("Cpub.dat","Cpri.dat");
FileInputStream fp = new FileInputStream("Cpub.dat");
ObjectInputStream bp = new ObjectInputStream(fp);
Key kp = (Key) bp.readObject();
ByteArrayOutputStream baos = new ByteArrayOutputStream();
ObjectOutputStream oos = new ObjectOutputStream(baos);
oos.writeObject(kp);
byte[] kb = baos.toByteArray();
out.writeUTF(kb.length + "");
for (int i = 0; i < kb.length; i++) {
out.writeUTF(kb[i] + "");
}
Thread.sleep(1000);
int len = Integer.parseInt(in.readUTF());
byte np[] = new byte[len];
for (int i = 0;i<len;i++) {
String temp = in.readUTF();
np[i] = Byte.parseByte(temp);
}
ObjectInputStream ois = new ObjectInputStream (new ByteArrayInputStream (np));
Key k2 = (Key)ois.readObject();;
FileOutputStream f2 = new FileOutputStream("Spub.dat");
ObjectOutputStream b2 = new ObjectOutputStream(f2);
b2.writeObject(k2);
KeyAgree.DH("Spub.dat","Cpri.dat");
FileInputStream f = new FileInputStream("sb.dat");
byte[] keysb = new byte[24];
f.read(keysb);
System.out.println("公共密钥：");
for (int i = 0;i<24;i++) {
System.out.print(keysb[i]+",");
}
System.out.println("");
SecretKeySpec k = new SecretKeySpec(keysb, "DESede");
Cipher cp = Cipher.getInstance("DESede");
cp.init(Cipher.ENCRYPT_MODE, k);
mybc.conversion(str);
String str1 = mybc.getMessage();
byte ptext[] = str1.getBytes("UTF-8");
byte ctext[] = cp.doFinal(ptext);
System.out.println("后缀表达式已被加密：");
for (int i = 0; i < ctext.length; i++) {
System.out.print(ctext[i] + ",");
}
System.out.println("");
out.writeUTF(ctext.length + "");
for (int i = 0; i < ctext.length; i++) {
out.writeUTF(ctext[i] + "");
}
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应:" + s);
} catch (Exception e) {
System.out.println("服务器已断开" + e);
}
}
}
import javax.crypto.KeyAgreement;
import javax.crypto.spec.SecretKeySpec;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.ObjectInputStream;
import java.security.PrivateKey;
import java.security.PublicKey;
public class KeyAgree{
public static void DH(String s1,String s2) throws Exception{
// 读取对方的DH公钥
FileInputStream f1=new FileInputStream(s1);
ObjectInputStream b1=new ObjectInputStream(f1);
PublicKey pbk=(PublicKey)b1.readObject( );
//读取自己的DH私钥
FileInputStream f2=new FileInputStream(s2);
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();
FileOutputStream fsb = new FileOutputStream("sb.dat");
fsb.write(sb);
}
}
import javax.crypto.spec.DHParameterSpec;
import java.io.FileOutputStream;
import java.io.ObjectOutputStream;
import java.math.BigInteger;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.PrivateKey;
import java.security.PublicKey;
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 DH(String s1,String s2) 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(s1);
ObjectOutputStream b1=new ObjectOutputStream(f1);
b1.writeObject(pbk);
// 保存私钥
FileOutputStream f2=new FileOutputStream(s2);
ObjectOutputStream b2=new ObjectOutputStream(f2);
b2.writeObject(prk);
}
}
import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
import java.io.*;
import java.net.ServerSocket;
import java.net.Socket;
import java.security.Key;
public class Server4 {
public static void main(String args[]) {
MyDC mydc = new MyDC();
ServerSocket serverForClient = null;
Socket socketOnServer = null;
DataOutputStream out = null;
DataInputStream in = null;
try {
serverForClient = new ServerSocket(5318);
} catch (IOException e1) {
System.out.println(e1);
}
try {
System.out.println("等待客户呼叫");
socketOnServer = serverForClient.accept(); //堵塞状态，除非有客户呼叫
System.out.println("客户已连接");
out = new DataOutputStream(socketOnServer.getOutputStream());
in = new DataInputStream(socketOnServer.getInputStream());
Key_DH.DH("Spub.dat","Spri.dat");
int len = Integer.parseInt(in.readUTF());
byte np[] = new byte[len];
for (int i = 0;i<len;i++) {
String temp = in.readUTF();
np[i] = Byte.parseByte(temp);
}
ObjectInputStream ois = new ObjectInputStream (new ByteArrayInputStream (np));
Key k2 = (Key)ois.readObject();;
FileOutputStream f2 = new FileOutputStream("Cpub.dat");
ObjectOutputStream b2 = new ObjectOutputStream(f2);
b2.writeObject(k2);
FileInputStream fp = new FileInputStream("Spub.dat");
ObjectInputStream bp = new ObjectInputStream(fp);
Key kp = (Key) bp.readObject();
ByteArrayOutputStream baos = new ByteArrayOutputStream();
ObjectOutputStream oos = new ObjectOutputStream(baos);
oos.writeObject(kp);
byte[] kb = baos.toByteArray();
out.writeUTF(kb.length + "");
for (int i = 0; i < kb.length; i++) {
out.writeUTF(kb[i] + "");
}
KeyAgree.DH("Cpub.dat","Spri.dat");
String leng = in.readUTF(); // in读取信息，堵塞状态
byte ctext[] = new byte[Integer.parseInt(leng)];
for (int i = 0;i<Integer.parseInt(leng);i++) {
String temp = in.readUTF();
ctext[i] = Byte.parseByte(temp);
}
// 获取密钥
FileInputStream f = new FileInputStream("sb.dat");
byte[] keysb = new byte[24];
f.read(keysb);
System.out.println("公共密钥：");
for (int i = 0;i<24;i++) {
System.out.print(keysb[i]+",");
}
System.out.println("");
SecretKeySpec k = new SecretKeySpec(keysb, "DESede");
// 解密
Cipher cp = Cipher.getInstance("DESede");
cp.init(Cipher.DECRYPT_MODE, k);
byte[] ptext = cp.doFinal(ctext);
System.out.println("");
// 显示明文
String p = new String(ptext,"UTF8");
System.out.println("被解密的后缀表达式：" + p);
System.out.println("计算后缀表达式" + p);
out.writeUTF(mydc.evaluate(p)+"");
} catch (Exception e) {
System.out.println("客户已断开" + e);
}
}
}
实验截图：
任务五：
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MyDC.java的功能计算后缀表达式的值，把结果发送给客户端实验代码：
import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;
import java.io.*;
import java.net.Socket;
import java.security.Key;
import java.util.Scanner;
public class Client5 {
public static void main(String args[]) {
MyBC mybc = new MyBC();
Socket mysocket;
DataInputStream in = null;
DataOutputStream out = null;
Scanner scanner = new Scanner(System.in);
String str;
try {
mysocket = new Socket("192.168.188.1", 5208);
System.out.println("客户端启动...");
in = new DataInputStream(mysocket.getInputStream());
out = new DataOutputStream(mysocket.getOutputStream());
System.out.println("请输入中缀表达式：");
str = scanner.nextLine();
Key_DH.DH("Cpub.dat","Cpri.dat");
FileInputStream fp = new FileInputStream("Cpub.dat");
ObjectInputStream bp = new ObjectInputStream(fp);
Key kp = (Key) bp.readObject();
ByteArrayOutputStream baos = new ByteArrayOutputStream();
ObjectOutputStream oos = new ObjectOutputStream(baos);
oos.writeObject(kp);
byte[] kb = baos.toByteArray();
out.writeUTF(kb.length + "");
for (int i = 0; i < kb.length; i++) {
out.writeUTF(kb[i] + "");
}
Thread.sleep(500);
int len = Integer.parseInt(in.readUTF());
byte np[] = new byte[len];
for (int i = 0;i<len;i++) {
String temp = in.readUTF();
np[i] = Byte.parseByte(temp);
}
ObjectInputStream ois = new ObjectInputStream (new ByteArrayInputStream (np));
Key k2 = (Key)ois.readObject();;
FileOutputStream f2 = new FileOutputStream("Spub.dat");
ObjectOutputStream b2 = new ObjectOutputStream(f2);
b2.writeObject(k2);
KeyAgree.DH("Spub.dat","Cpri.dat");
FileInputStream f = new FileInputStream("sb.dat");
byte[] keysb = new byte[24];
f.read(keysb);
System.out.println("公共密钥：");
for (int i = 0;i<24;i++) {
System.out.print(keysb[i]+",");
}
System.out.println("");
SecretKeySpec k = new SecretKeySpec(keysb, "DESede");
Cipher cp = Cipher.getInstance("DESede");
cp.init(Cipher.ENCRYPT_MODE, k);
mybc.conversion(str);
String str1 = mybc.getMessage();
byte ptext[] = str1.getBytes("UTF-8");
String ptextMd5 = DigestPass.DP(str1);
System.out.println("明文的MD5值："+ptextMd5);
byte ctext[] = cp.doFinal(ptext);
System.out.println("被加密的后缀表达式：");
for (int i = 0; i < ctext.length; i++) {
System.out.print(ctext[i] + ",");
}
System.out.println("");
out.writeUTF(ctext.length + "");
for (int i = 0; i < ctext.length; i++) {
out.writeUTF(ctext[i] + "");
}
out.writeUTF(ptextMd5);
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应:" + s);
} catch (Exception e) {
System.out.println("服务器已断开" + e);
}
}
}
import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;
import java.io.*;
import java.net.ServerSocket;
import java.net.Socket;
import java.security.Key;
public class Server5 {
public static void main(String args[]) {
MyDC mydc = new MyDC();
ServerSocket serverForClient = null;
Socket socketOnServer = null;
DataOutputStream out = null;
DataInputStream in = null;
try {
serverForClient = new ServerSocket(5318);
} catch (IOException e1) {
System.out.println(e1);
}
try {
System.out.println("等待客户呼叫");
socketOnServer = serverForClient.accept(); //堵塞状态，除非有客户呼叫
System.out.println("客户已连接");
out = new DataOutputStream(socketOnServer.getOutputStream());
in = new DataInputStream(socketOnServer.getInputStream());
Key_DH.DH("Spub.dat","Spri.dat");
int len = Integer.parseInt(in.readUTF());
byte np[] = new byte[len];
for (int i = 0;i<len;i++) {
String temp = in.readUTF();
np[i] = Byte.parseByte(temp);
}
ObjectInputStream ois = new ObjectInputStream (new ByteArrayInputStream(np));
Key k2 = (Key)ois.readObject();;
FileOutputStream f2 = new FileOutputStream("Cpub.dat");
ObjectOutputStream b2 = new ObjectOutputStream(f2);
b2.writeObject(k2);
FileInputStream fp = new FileInputStream("Spub.dat");
ObjectInputStream bp = new ObjectInputStream(fp);
Key kp = (Key) bp.readObject();
ByteArrayOutputStream baos = new ByteArrayOutputStream();
ObjectOutputStream oos = new ObjectOutputStream(baos);
oos.writeObject(kp);
byte[] kb = baos.toByteArray();
out.writeUTF(kb.length + "");
for (int i = 0; i < kb.length; i++) {
out.writeUTF(kb[i] + "");
}
KeyAgree.DH("Cpub.dat","Spri.dat");
String leng = in.readUTF(); // in读取信息，堵塞状态
byte ctext[] = new byte[Integer.parseInt(leng)];
for (int i = 0;i<Integer.parseInt(leng);i++) {
String temp = in.readUTF();
ctext[i] = Byte.parseByte(temp);
}
String check = in.readUTF();
// 获取密钥
FileInputStream f = new FileInputStream("sb.dat");
byte[] keysb = new byte[24];
f.read(keysb);
System.out.println("公共密钥：");
for (int i = 0;i<24;i++) {
System.out.print(keysb[i]+",");
}
System.out.println("");
SecretKeySpec k = new SecretKeySpec(keysb, "DESede");
// 解密
Cipher cp = Cipher.getInstance("DESede");
cp.init(Cipher.DECRYPT_MODE, k);
byte[] ptext = cp.doFinal(ctext);
System.out.println("");
// 显示明文
String p = new String(ptext, "UTF8");
String pMd5 = DigestPass.DP(p);
System.out.println("被解密明文的MD5值："+pMd5);
if (pMd5.equals(check)){
System.out.println("和客户端的MD5值一致");
System.out.println("计算后缀表达式" + p);
out.writeUTF(mydc.evaluate(p)+"");
}
else {
System.out.println("警告：和客户端的MD5值不一致！");
}
} catch (Exception e) {
System.out.println("客户已断开" + e);
}
}
}
实验截图：
码云连接：https://gitee.com/zhangjiahua20175208/codes
实验感悟：
本次实验考察的是网络编程与安全，基于四则运算来进行的，与以前进行的实验有相同部分，可以参考以前的代码，所以这次实验并不是很困难。两人结对的方式也让实验可以互帮互助，减轻实验的压力，客服端/服务器功能在学习的时候并不是很牢固，通过这次的实验，在应用上有了更好地掌握。
20175208 2018-2019-实验五 网络编程与安全
标签：jpg menu 客户 cas byte read 顺序 通过 ack
原文地址：https://www.cnblogs.com/kaoru/p/10962838.html
