java实验 Tcp传输
实验内容
-
运行代码一人服务器，一人客户端。
-
下载加解密代码，先编译运行代码，一人加密一人解密，适当修改代码。
-
集成代码，一人加密后通过TCP发送，加密使用AES或DES，AES或DES加密密钥Key的发送，使用服务器的公钥加密，公钥算法用RSA或DH，发送信息的完整性验证使用MD5。
-
使用试验后git服务托管代码。
5.Blog。
PSP(Personal Software Process)
| 步骤 | 耗时（分钟） | 百分比 |
|---|---|---|
| 需求分析 | 40 | 18.2 |
| 设计 | 30 | 13.63 |
| 代码实现 | 60 | 27.27 |
| 测试 | 60 | 27.27 |
| 分析总结 | 30 | 13.64 |
实验步骤
- 服务器端与客户端连接,当有客户端连接到达时，建立一个和客户端连接对应的Socket连 接对象.
IP地址查询：
服务器端：
import java.io.*;
import java.net.ServerSocket;
import java.net.Socket;
public class ServerTest
{
public static final int PORT = 8081;
public static void main(String[] args) throws IOException
{
ServerSocket s = new ServerSocket(PORT);
System.out.println("Started:"+s);
try
{
Socket socket = s.accept();
try
{
System.out.println("Connection accepted:"+socket);
BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
PrintWriter out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(socket.getOutputStream())),true);
while(true)
{
String str=in.readLine();
if(str.equals("END"))
break;
System.out.print("Echoing:"+str);
out.println(str);
}
}
finally
{
System.out.println("closing...");
socket.close();
}
}
finally
{
s.close();
}
}
}
结果：
客户端：
import java.io.*;
import java.net.InetAddress;
import java.net.Socket;;
public class ClientTest
{
public static void main(String[] args) throws IOException
{
InetAddress addr = InetAddress.getByName("172.16.64.27");
System.out.println("addr ="+addr);
Socket socket = new Socket(addr,ServerTest.PORT);
try
{
System.out.println("socket="+socket);
BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
PrintWriter out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(socket.getOutputStream())),true);
for(int i =0;i<0;i++)
{
out.println("howdy"+i);
String str = in.readLine();
System.out.println(str);
}
out.println("END");
}
finally
{
System.out.println("closing...");
socket.close();
}
}
}
结果：
- 运行加解密包中的程序
运行DES加密代码
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);
// 打印密钥编码中的内容
for(int i=0;i<kb.length;i++){
System.out.print(kb[i]+",");
}
}
}
- 整合代码
// file name：ComputeTCPClient.java
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 ComputeTCPClient {
public static void main(String srgs[]) throws Exception{
try {
KeyGenerator kg=KeyGenerator.getInstance("DESede");
kg.init(168);
SecretKey k=kg.generateKey( );
byte[] ptext2=k.getEncoded();
//String kstr=parseByte2HexStr(kb);
//创建连接特定服务器的指定端口的Socket对象
Socket socket = new Socket("172.16.64.27", 4421);
//获得从服务器端来的网络输入流
BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
//获得从客户端向服务器端输出数据的网络输出流
PrintWriter out=new PrintWriter(new BufferedWriter(new OutputStreamWriter(socket.getOutputStream())),true);
//创建键盘输入流，以便客户端从键盘上输入信息
BufferedReader stdin = new BufferedReader(new InputStreamReader(System.in));
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();
//System.out.println("e= "+e);
//System.out.println("n= "+n);
//byte ptext2[]=kstr.getBytes("UTF8");
BigInteger m=new BigInteger(ptext2);
BigInteger c=m.modPow(e,n);
//System.out.println("c= "+c);
String cs=c.toString( );
out.println(cs); //通过网络传送到服务器
System.out.print("请输入待发送的数据：");
String s=stdin.readLine(); //从键盘读入待发送的数据
Cipher cp=Cipher.getInstance("DESede");
cp.init(Cipher.ENCRYPT_MODE, k);
byte ptext[]=s.getBytes("UTF8");
byte ctext[]=cp.doFinal(ptext);
String str=parseByte2HexStr(ctext);
out.println(str); //通过网络传送到服务器
String x=s;
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(result);
out.println(result);
str=in.readLine();//从网络输入流读取结果
System.out.println( "从服务器接收到的结果为："+str); //输出服务器返回的结果
}
catch (Exception e) {
System.out.println(e);
}
finally{
//stdin.close();
//in.close();
//out.close();
//socket.close();
}
}
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();
}
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;
}
}
结果：
