我正在从 Facebook android 应用程序中嗅探数据包。我想在研究社交网络上的用户行为时使用嗅探到的数据。
我在过去两个月学到的是，我必须创建一个 vpn 服务并用它来嗅探数据。互联网上有很多有用的代码，我试图理解和运行。我设法使用这些代码嗅探了一些应用程序的数据，它们都使用相同的概念。
- https://github.com/hexene/LocalVPN
- 带有 VpnService 的 Android 防火墙
- http://www.thegeekstuff.com/2014/06/Android-vpn-service/
- Android VpnService 抓包不会抓包
当使用上述每一个代码并稍作修改时，我设法捕获了所有应用程序的数据包，但是对于像 facebook 这样的应用程序，vpnService 使这些应用程序停止工作；当我创建 vpn 服务并尝试例如对帖子发表评论或进行任何需要在 Facebook 应用程序和 Facebook 服务器之间发送/接收数据的操作时，此操作不会发生；看起来 Facebook 应用程序以某种方式知道有人在嗅他。
在过去的两个月里，我一直在尝试寻找一种在不破坏 Facebook 应用程序功能的情况下捕获 Facebook 应用程序数据包的方法。
我尝试在 android 示例中的KeyChain 演示之后安装证书，但它不适用于我。
从我的搜索中，我知道/我确定我缺少一些东西；我搜索了一些应用程序，这些应用程序可以完成我想要完成的工作，而不会让 facebook 等应用程序检测到它。我在 google play 上找到了 LostNetNoRootFirewall 。
使用LostNetNoRootFirewall，我设法创建了一个 vpn 服务并嗅探数据包，而 facebook 应用程序就像一个魅力一样工作！
我的问题
我应该在我的应用程序中添加什么才能创建 vpnService 并防止像 facebook 这样的应用程序检测到我的服务正在嗅探它的数据包？
我正在使用的当前代码。【原文出处】
package com.git.firewall;
public class GITVpnService extends VpnService implements Handler.Callback, Runnable {
private static final String TAG = "GITVpnService";
private String mServerAddress = "127.0.0.1";
private int mServerPort = 55555;
private PendingIntent mConfigureIntent;
private Handler mHandler;
private Thread mThread;
private ParcelFileDescriptor mInterface;
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
// The handler is only used to show messages.
if (mHandler == null) {
mHandler = new Handler(this);
}
// Stop the previous session by interrupting the thread.
if (mThread != null) {
mThread.interrupt();
}
// Start a new session by creating a new thread.
mThread = new Thread(this, "VpnThread");
mThread.start();
return START_STICKY;
}
@Override
public void onDestroy() {
if (mThread != null) {
mThread.interrupt();
}
}
@Override
public boolean handleMessage(Message message) {
if (message != null) {
Toast.makeText(this, (String)message.obj, Toast.LENGTH_SHORT).show();
}
return true;
}
@Override
public synchronized void run() {
try {
Log.i(TAG, "Starting");
InetSocketAddress server = new InetSocketAddress(
mServerAddress, mServerPort);
run(server);
} catch (Exception e) {
Log.e(TAG, "Got " + e.toString());
try {
mInterface.close();
} catch (Exception e2) {
// ignore
}
Message msgObj = mHandler.obtainMessage();
msgObj.obj = "Disconnected";
mHandler.sendMessage(msgObj);
} finally {
}
}
DatagramChannel mTunnel = null;
private boolean run(InetSocketAddress server) throws Exception {
boolean connected = false;
android.os.Debug.waitForDebugger();
// Create a DatagramChannel as the VPN tunnel.
mTunnel = DatagramChannel.open();
// Protect the tunnel before connecting to avoid loopback.
if (!protect(mTunnel.socket())) {
throw new IllegalStateException("Cannot protect the tunnel");
}
// Connect to the server.
mTunnel.connect(server);
// For simplicity, we use the same thread for both reading and
// writing. Here we put the tunnel into non-blocking mode.
mTunnel.configureBlocking(false);
// Authenticate and configure the virtual network interface.
handshake();
// Now we are connected. Set the flag and show the message.
connected = true;
Message msgObj = mHandler.obtainMessage();
msgObj.obj = "Connected";
mHandler.sendMessage(msgObj);
new Thread ()
{
public void run ()
{
// Packets to be sent are queued in this input stream.
FileInputStream in = new FileInputStream(mInterface.getFileDescriptor());
// Allocate the buffer for a single packet.
ByteBuffer packet = ByteBuffer.allocate(32767);
int length;
try
{
while (true)
{
while ((length = in.read(packet.array())) > 0) {
// Write the outgoing packet to the tunnel.
packet.limit(length);
debugPacket(packet); // Packet size, Protocol, source, destination
mTunnel.write(packet);
packet.clear();
}
}
}
catch (IOException e)
{
e.printStackTrace();
}
}
}.start();
new Thread ()
{
public void run ()
{
DatagramChannel tunnel = mTunnel;
// Allocate the buffer for a single packet.
ByteBuffer packet = ByteBuffer.allocate(8096);
// Packets received need to be written to this output stream.
FileOutputStream out = new FileOutputStream(mInterface.getFileDescriptor());
while (true)
{
try
{
// Read the incoming packet from the tunnel.
int length;
while ((length = tunnel.read(packet)) > 0)
{
// Write the incoming packet to the output stream.
out.write(packet.array(), 0, length);
packet.clear();
}
}
catch (IOException ioe)
{
ioe.printStackTrace();
}
}
}
}.start();
return connected;
}
private void handshake() throws Exception {
if (mInterface == null)
{
Builder builder = new Builder();
builder.setMtu(1500);
builder.addAddress("10.0.0.2",32);
builder.addRoute("0.0.0.0", 0);
//builder.addRoute("192.168.2.0",24);
//builder.addDnsServer("8.8.8.8");
// Close the old interface since the parameters have been changed.
try {
mInterface.close();
} catch (Exception e) {
// ignore
}
// Create a new interface using the builder and save the parameters.
mInterface = builder.setSession("GIT VPN")
.setConfigureIntent(mConfigureIntent)
.establish();
}
}
private void debugPacket(ByteBuffer packet)
{
/*
for(int i = 0; i < length; ++i)
{
byte buffer = packet.get();
Log.d(TAG, "byte:"+buffer);
}*/
int buffer = packet.get();
int version;
int headerlength;
version = buffer >> 4;
headerlength = buffer & 0x0F;
headerlength *= 4;
Log.d(TAG, "IP Version:"+version);
Log.d(TAG, "Header Length:"+headerlength);
String status = "";
status += "Header Length:"+headerlength;
buffer = packet.get(); //DSCP + EN
buffer = packet.getChar(); //Total Length
Log.d(TAG, "Total Length:"+buffer);
buffer = packet.getChar(); //Identification
buffer = packet.getChar(); //Flags + Fragment Offset
buffer = packet.get(); //Time to Live
buffer = packet.get(); //Protocol
Log.d(TAG, "Protocol:"+buffer);
status += " Protocol:"+buffer;
buffer = packet.getChar(); //Header checksum
String sourceIP = "";
buffer = packet.get(); //Source IP 1st Octet
sourceIP += buffer;
sourceIP += ".";
buffer = packet.get(); //Source IP 2nd Octet
sourceIP += buffer;
sourceIP += ".";
buffer = packet.get(); //Source IP 3rd Octet
sourceIP += buffer;
sourceIP += ".";
buffer = packet.get(); //Source IP 4th Octet
sourceIP += buffer;
Log.d(TAG, "Source IP:"+sourceIP);
status += " Source IP:"+sourceIP;
String destIP = "";
buffer = packet.get(); //Destination IP 1st Octet
destIP += buffer;
destIP += ".";
buffer = packet.get(); //Destination IP 2nd Octet
destIP += buffer;
destIP += ".";
buffer = packet.get(); //Destination IP 3rd Octet
destIP += buffer;
destIP += ".";
buffer = packet.get(); //Destination IP 4th Octet
destIP += buffer;
Log.d(TAG, "Destination IP:"+destIP);
status += " Destination IP:"+destIP;
/*
msgObj = mHandler.obtainMessage();
msgObj.obj = status;
mHandler.sendMessage(msgObj);
*/
//Log.d(TAG, "version:"+packet.getInt());
//Log.d(TAG, "version:"+packet.getInt());
//Log.d(TAG, "version:"+packet.getInt());
}
}