2018-2019-2 20175226 实验五《网络编程与安全》实验报告
任务一
实验要求
-两人一组结对编程：
- 参考http://www.cnblogs.com/rocedu/p/6766748.html#SECDSA
- 结对实现中缀表达式转后缀表达式的功能 MyBC.java
- 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
- 上传测试代码运行结果截图和码云链接
实验原理
- 中缀转后缀表达式
- 遇到数字，我们就直接将其输出。
- 遇到非数字时，若栈为空或者该符号为左括号或者栈顶元素为括号，直接入栈。
- 遇到一个右括号，持续出栈并输出符号，直到栈顶元素为左括号，然后将左括号出栈（注意，左括号只出栈，不输出），右括号不入栈。
- 遇到运算符号且栈非空，查看栈顶元素，如果栈顶元素的运算优先级大于或者等于该运算符号，则持续出栈，直到栈顶元素优先级小于该运算符。最后将该元素入栈。
- 我们读到了输入的末尾，则将栈中所有元素依次弹出。
- 通过后缀表达式计算结果
- 建立一个空栈，遇到数字就入栈，遇到符号就以符号前面的两个数为运算数进行计算
实验代码
- 中缀转后缀表达式
MyBC.java
package 实验五;
import java.util.Stack;
public class MyBC{
String jieguo = "";
public MyBC (String[] args) {
Stack z = new Stack();
String t = "";
for (int i = 0; i < args.length; i++) {
switch (args[i]) {
case "(":
z.push(args[i]);
break;
case "+":
case "-":
while(z.empty() != true) {
t = z.pop();
if (t.equals("(")) {
z.push(t);
break;
}
jieguo = jieguo + t + " ";
}
z.push(args[i]);
break;
case "*":
case "/":
while(z.empty() != true) {
t = z.pop();
if (t.equals("+") || t.equals("-") || t.equals("(")) {
z.push(t);
break;
}
jieguo = jieguo + t + " ";
}
z.push(args[i]);
break;
case ")":
while (z.empty()== false) {
t = z.pop();
if (t.equals("(")) {
break;
} else {
jieguo = jieguo + t + " ";
}
}
break;
case" ":
break;
default:
jieguo = jieguo + args[i] + " ";
break;
}
}
while (z.empty() == false) {
jieguo = jieguo + z.pop() + " ";
}
System.out.println(jieguo);
}
} - 后缀表达式计算
MyDC.java
package 实验五;
import java.util.Stack;
public class MyDC{
private static Integer answer;
public MyDC (String[] args) {
Stack z = new Stack();
int num1,num2,d;
for(int i=0;i - 测试代码
shiyan5_1 .java
package 实验五;
import java.util.Scanner;
public class shiyan5_1 {
public static void main(String[] args) {
String question = "";
int result;
Scanner scanner = new Scanner(System.in);
System.out.println("请输入题目：");
question = scanner.nextLine();
String [] str = question.split(" ");
System.out.println("转置结果如下：");
MyBC translate = new MyBC(str);
String [] str2 = translate.jieguo.split(" ");
System.out.println("计算结果如下：");
MyDC answer = new MyDC(str2);
}
}实验截图
任务二
实验要求
- 结对编程：1人负责客户端，一人负责服务器
- 注意责任归宿，要会通过测试证明自己没有问题
- 基于Java Socket实现客户端/服务器功能，传输方式用TCP
- 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
- 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
- 客户端显示服务器发送过来的结果
实验过程及原理
- 使用
InetAddress类的静态方法getLocalHost()获得一个InetAddress的对象，该对象含有本地机器的IP地址 - 客户端套接字：
Socket clientSocket = new Socket("服务器的IP地址",一个端口号) - SeverSocket对象与服务器端套接字：
SeverSocket severForClient = new SeverSocket(端口号) - 使用accept()方法将客户端和服务器的套接字连接起来：
Socket sc = severForClient.accept()
实验代码
- 访问本机IP
getHostAddress.java
package 实验五;
import java.net.*;
public class getHostAddress {
public static void main(String[] args) {
try{
InetAddress hostaddress = InetAddress.getLocalHost();
System.out.println(hostaddress.toString());
}catch (UnknownHostException e){
System.out.println(e);
}
}
}- 客户端
Client.java
package 实验五;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.net.Socket;
import java.util.Scanner;
public class Client {
public static void main(String[] args) {
Scanner inn = new Scanner(System.in);
Socket mysocket;
DataInputStream in = null;
DataOutputStream out = null;
try{
mysocket = new Socket("169.254.92.198",2010);
in = new DataInputStream(mysocket.getInputStream());
out = new DataOutputStream(mysocket.getOutputStream());
System.out.println("请输入中缀表达式：");
String infix = inn.nextLine();
String [] str = infix.split(" ");
System.out.println("已传递后缀表达式");
MyBC suffix =new MyBC(str);
out.writeUTF(suffix.jieguo);
String result = in.readUTF();
System.out.println("已收到计算结果"+result);
Thread.sleep(500);
}catch (Exception e){
System.out.println("双方已断开连接"+e);
}
}
}- 服务器
Sever.java
package 实验五;
import com.sun.xml.internal.ws.policy.privateutil.PolicyUtils;
import java.io.*;
import java.net.*;
public class Sever {
public static void main(String[] args) {
ServerSocket serverForClient = null;
Socket socketOnServer = null;
DataOutputStream out = null;
DataInputStream in = null;
try{
serverForClient = new ServerSocket(2010);
}catch (IOException e){
System.out.println("双方已断开连接"+e);
}
try{
System.out.println("准备接受对方传来的问题");
socketOnServer = serverForClient.accept();
out = new DataOutputStream(socketOnServer.getOutputStream());
in = new DataInputStream(socketOnServer.getInputStream());
String suffix = in.readUTF();
String [] str = suffix.split(" ");
System.out.println("收到问题，正在解决:"+suffix);
System.out.println("已传输得出结果：");
MyDC myDC = new MyDC(str);
String answer = String.valueOf(myDC.answer);
out.writeUTF(answer+"");
Thread.sleep(500);
}catch (Exception e){
System.out.println("双方已断开连接");
}
}
}实验截图
访问本机IP
客户端
服务器
任务三
实验要求
- 加密结对编程：
- 注意责任归宿，要会通过测试证明自己没有问题
- 基于Java Socket实现客户端/服务器功能，传输方式用TCP
- 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
- 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
- 客户端显示服务器发送过来的结果
实验原理及过程
- 客户端
- 获取并初始化密钥生成器
KeyGenerator kg=KeyGenerator.getInstance("DESede")、kg.init(168); - 生成密钥
SecretKey k=kg.generateKey( ); - 传送密钥长度及密钥内容
- 创建并初始化密码器
Cipher cp=Cipher.getInstance("DESede")、cp.init(Cipher.ENCRYPT_MODE, k); - 执行加密
byte []ptext=cp.doFinal(ctext)
- 获取并初始化密钥生成器
- 服务器
- 接收密钥长度、密钥内容
- 创建并初始化密码器
Cipher cp=Cipher.getInstance("DESede")、cp.init(Cipher.DECRYPT_MODE, k); - 执行解密
byte []ptext=cp.doFinal(ctext)
实验代码
- 客户端
Client.java
package 实验五;
import java.io.*;
import java.net.*;
import javax.crypto.*;
import java.util.Scanner;
public class Client5_3 {
public static void main(String[] args) {
Scanner inn = new Scanner(System.in);
Socket mysocket;
DataInputStream in = null;
DataOutputStream out = null;
try{
mysocket = new Socket("169.254.92.198",2010);
in = new DataInputStream(mysocket.getInputStream());
out = new DataOutputStream(mysocket.getOutputStream());
KeyGenerator kg = KeyGenerator.getInstance("DESede");
kg.init(168);
SecretKey k = kg.generateKey();
byte []kb = k.getEncoded();
out.writeUTF(kb.length+ "");
System.out.println("产生的密钥为");
for(int i=0;i- 服务器
Sever,java
package 实验五;
import com.sun.xml.internal.ws.policy.privateutil.PolicyUtils;
import java.io.*;
import java.net.*;
import javax.crypto.*;
import javax.crypto.spec.*;
public class Sever5_3 {
public static void main(String[] args) {
ServerSocket serverForClient = null;
Socket socketOnServer = null;
DataOutputStream out = null;
DataInputStream in = null;
try{
serverForClient = new ServerSocket(2010);
}catch (IOException e){
System.out.println("双方已断开连接"+e);
}
try{
System.out.println("准备接受对方传来的问题");
socketOnServer = serverForClient.accept();
out = new DataOutputStream(socketOnServer.getOutputStream());
in = new DataInputStream(socketOnServer.getInputStream());
String keylength = in.readUTF();
byte []kb = new byte[Integer.parseInt(keylength)];
System.out.println("收到的密钥为：");
for(int i = 0;i实验截图
客户端
服务器
任务四
实验要求
- 密钥分发结对编程：
- 注意责任归宿，要会通过测试证明自己没有问题
- 基于Java Socket实现客户端/服务器功能，传输方式用TCP
- 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
- 客户端和服务器用DH算法进行3DES或AES算法的密钥交换
- 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
- 客户端显示服务器发送过来的结果
实验原理及过程
- 客户端和服务器分别产生自己的公钥和私钥，并用过字节数组的形式分别向另一方传递自己的公钥；
- 客户端和服务器接受对方的公钥后利用自己的私钥创建共享密钥；
- 创建并初始化密钥协定对象
KeyAgreement ka=KeyAgreement.getInstance("DH")、ka.init(prk); - 执行密钥协定
ka.doPhase(pbk,true); - 生成共享信息
byte[ ] sb=ka.generateSecret(); - 从文件中读取信息并给出共享密钥
实验代码
key_DH.java、keyAgree.java
package 实验五;
import java.io.*;
import java.math.*;
import java.security.*;
import javax.crypto.spec.*;
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 str1,String str2) 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(str1);
ObjectOutputStream b1=new ObjectOutputStream(f1);
b1.writeObject(pbk);
// 保存私钥
FileOutputStream f2=new FileOutputStream(str2);
ObjectOutputStream b2=new ObjectOutputStream(f2);
b2.writeObject(prk);
}
}
package 实验五;
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 Agree(String str1,String str2) throws Exception{
// 读取对方的DH公钥
FileInputStream f1=new FileInputStream(str1);
ObjectInputStream b1=new ObjectInputStream(f1);
PublicKey pbk=(PublicKey)b1.readObject( );
//读取自己的DH私钥
FileInputStream f2=new FileInputStream(str2);
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);
}
}- 客户端
Client5_4.java
package 实验五;
import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;
import java.io.*;
import java.security.*;
import java.util.Scanner;
import java.net.*;
public class Client5_4 {
public static void main(String[] args) {
Scanner inn = new Scanner(System.in);
Socket mysocket;
DataInputStream in = null;
DataOutputStream out = null;
try{
mysocket = new Socket("169.254.92.198",2010);
in = new DataInputStream(mysocket.getInputStream());
out = new DataOutputStream(mysocket.getOutputStream());
Key_DH.DH ("Lpub.dat","Lpri.dat");
FileInputStream my = new FileInputStream("Lpub.dat");
ObjectInputStream mypub = new ObjectInputStream(my);
Key kp = (Key) mypub.readObject();
ByteArrayOutputStream DH = new ByteArrayOutputStream();
ObjectOutputStream myDH = new ObjectOutputStream(DH);
myDH.writeObject(kp);
byte []pub = DH.toByteArray();
out.writeUTF(pub.length+"");
for(int i=0;i- 服务器
Sever5_4,java
package 实验五;
import com.sun.xml.internal.ws.policy.privateutil.PolicyUtils;
import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;
import java.io.*;
import java.net.ServerSocket;
import java.net.Socket;
import java.security.*;
public class Sever5_4 {
public static void main(String[] args) {
ServerSocket serverForClient = null;
Socket socketOnServer = null;
DataOutputStream out = null;
DataInputStream in = null;
try{
serverForClient = new ServerSocket(2010);
}catch (IOException e){
System.out.println("双方已断开连接"+e);
}
try{
System.out.println("准备接受对方传来的问题");
socketOnServer = serverForClient.accept();
out = new DataOutputStream(socketOnServer.getOutputStream());
in = new DataInputStream(socketOnServer.getInputStream());
Key_DH.DH("Wpub.dat","Wpri.dat");
int length = Integer.parseInt(in.readUTF());
byte cpub[] = new byte[length];
for(int i=0;i实验截图
客户端
服务器
任务五
实验要求
- 完整性校验结对编程：
- 注意责任归宿，要会通过测试证明自己没有问题
- 基于Java Socket实现客户端/服务器功能，传输方式用TCP
- 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
- 客户端和服务器用DH算法进行3DES或AES算法的密钥交换
- 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
- 客户端显示服务器发送过来的结果
实验原理
- Java密码学算法中“Java摘要算法- MD5”部分的内容
实验代码
- MD5
DigestPass.java
package 实验五;
import java.security.*;
public class DigestPass{
public static String MD5(String str) throws Exception{
String x=str;
MessageDigest m=MessageDigest.getInstance("MD5");
m.update(x.getBytes("UTF8"));
byte s[ ]=m.digest( );
String result="";
for (int i=0; i- 客户端
Client5_5
package 实验五;
import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;
import java.io.*;
import java.net.Socket;
import java.security.*;
import java.util.Scanner;
import java.net.*;
public class Client5_5 {
public static void main(String[] args) {
Scanner inn = new Scanner(System.in);
Socket mysocket;
DataInputStream in = null;
DataOutputStream out = null;
try{
mysocket = new Socket("169.254.92.198",2010);
in = new DataInputStream(mysocket.getInputStream());
out = new DataOutputStream(mysocket.getOutputStream());
Key_DH.DH("Lpub.dat","Lpri.dat");
FileInputStream my = new FileInputStream("Lpub.dat");
ObjectInputStream mypub = new ObjectInputStream(my);
Key kp = (Key) mypub.readObject();
ByteArrayOutputStream DH = new ByteArrayOutputStream();
ObjectOutputStream myDH = new ObjectOutputStream(DH);
myDH.writeObject(kp);
byte []pub = DH.toByteArray();
out.writeUTF(pub.length+"");
for(int i=0;i- 服务器
Sever.java
package 实验五;
import com.sun.xml.internal.ws.policy.privateutil.PolicyUtils;
import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;
import java.io.*;
import java.net.ServerSocket;
import java.net.Socket;
import java.security.*;
public class Sever5_5 {
public static void main(String[] args) {
ServerSocket serverForClient = null;
Socket socketOnServer = null;
DataOutputStream out = null;
DataInputStream in = null;
try{
serverForClient = new ServerSocket(2010);
}catch (IOException e){
System.out.println("双方已断开连接"+e);
}
try{
System.out.println("准备接受对方传来的问题");
socketOnServer = serverForClient.accept();
out = new DataOutputStream(socketOnServer.getOutputStream());
in = new DataInputStream(socketOnServer.getInputStream());
Key_DH.DH("Wpub.dat","Wpri.dat");
int length = Integer.parseInt(in.readUTF());
byte cpub[] = new byte[length];
for(int i=0;i实验截图
客户端
服务器
