我想连接 VPN 服务器，但我不想使用密钥。目前，我发现以编程方式创建 vpn 连接的代码片段如下：
MyVpn客户端：
package com.example.android.toyvpn;
import android.app.Activity;
import android.content.Intent;
import android.content.SharedPreferences;
import android.net.VpnService;
import android.os.Bundle;
import android.widget.TextView;
public class ToyVpnClient extends Activity {
public interface Prefs {
String NAME = "connection";
String SERVER_ADDRESS = "server.address";
String SERVER_PORT = "server.port";
String SHARED_SECRET = "shared.secret";
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.form);
final TextView serverAddress = (TextView) findViewById(R.id.address);
final TextView serverPort = (TextView) findViewById(R.id.port);
final TextView sharedSecret = (TextView) findViewById(R.id.secret);
final SharedPreferences prefs = getSharedPreferences(Prefs.NAME, MODE_PRIVATE);
serverAddress.setText(prefs.getString(Prefs.SERVER_ADDRESS, ""));
serverPort.setText(prefs.getString(Prefs.SERVER_PORT, ""));
sharedSecret.setText(prefs.getString(Prefs.SHARED_SECRET, ""));
findViewById(R.id.connect).setOnClickListener(v -> {
prefs.edit()
.putString(Prefs.SERVER_ADDRESS, serverAddress.getText().toString())
.putString(Prefs.SERVER_PORT, serverPort.getText().toString())
.putString(Prefs.SHARED_SECRET, sharedSecret.getText().toString())
.commit();
Intent intent = VpnService.prepare(ToyVpnClient.this);
if (intent != null) {
startActivityForResult(intent, 0);
} else {
onActivityResult(0, RESULT_OK, null);
}
});
findViewById(R.id.disconnect).setOnClickListener(v -> {
startService(getServiceIntent().setAction(ToyVpnService.ACTION_DISCONNECT));
});
}
@Override
protected void onActivityResult(int request, int result, Intent data) {
if (result == RESULT_OK) {
startService(getServiceIntent().setAction(ToyVpnService.ACTION_CONNECT));
}
}
private Intent getServiceIntent() {
return new Intent(this, ToyVpnService.class);
}
}
我的VPN连接：
package com.example.android.toyvpn;
import static java.nio.charset.StandardCharsets.US_ASCII;
import android.app.PendingIntent;
import android.net.VpnService;
import android.os.ParcelFileDescriptor;
import android.util.Log;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.net.InetSocketAddress;
import java.net.SocketAddress;
import java.net.SocketException;
import java.nio.ByteBuffer;
import java.nio.channels.DatagramChannel;
import java.util.concurrent.TimeUnit;
public class ToyVpnConnection implements Runnable {
/**
* Callback interface to let the {@link ToyVpnService} know about new connections
* and update the foreground notification with connection status.
*/
public interface OnEstablishListener {
void onEstablish(ParcelFileDescriptor tunInterface);
}
/** Maximum packet size is constrained by the MTU, which is given as a signed short. */
private static final int MAX_PACKET_SIZE = Short.MAX_VALUE;
/** Time to wait in between losing the connection and retrying. */
private static final long RECONNECT_WAIT_MS = TimeUnit.SECONDS.toMillis(3);
/** Time between keepalives if there is no traffic at the moment.
*
* TODO: don't do this; it's much better to let the connection die and then reconnect when
* necessary instead of keeping the network hardware up for hours on end in between.
**/
private static final long KEEPALIVE_INTERVAL_MS = TimeUnit.SECONDS.toMillis(15);
/** Time to wait without receiving any response before assuming the server is gone. */
private static final long RECEIVE_TIMEOUT_MS = TimeUnit.SECONDS.toMillis(20);
/**
* Time between polling the VPN interface for new traffic, since it's non-blocking.
*
* TODO: really don't do this; a blocking read on another thread is much cleaner.
*/
private static final long IDLE_INTERVAL_MS = TimeUnit.MILLISECONDS.toMillis(100);
/**
* Number of periods of length {@IDLE_INTERVAL_MS} to wait before declaring the handshake a
* complete and abject failure.
*
* TODO: use a higher-level protocol; hand-rolling is a fun but pointless exercise.
*/
private static final int MAX_HANDSHAKE_ATTEMPTS = 50;
private final VpnService mService;
private final int mConnectionId;
private final String mServerName;
private final int mServerPort;
private final byte[] mSharedSecret;
private PendingIntent mConfigureIntent;
private OnEstablishListener mOnEstablishListener;
public ToyVpnConnection(final VpnService service, final int connectionId,
final String serverName, final int serverPort, final byte[] sharedSecret) {
mService = service;
mConnectionId = connectionId;
mServerName = serverName;
mServerPort= serverPort;
mSharedSecret = sharedSecret;
}
/**
* Optionally, set an intent to configure the VPN. This is {@code null} by default.
*/
public void setConfigureIntent(PendingIntent intent) {
mConfigureIntent = intent;
}
public void setOnEstablishListener(OnEstablishListener listener) {
mOnEstablishListener = listener;
}
@Override
public void run() {
try {
Log.i(getTag(), "Starting");
// If anything needs to be obtained using the network, get it now.
// This greatly reduces the complexity of seamless handover, which
// tries to recreate the tunnel without shutting down everything.
// In this demo, all we need to know is the server address.
final SocketAddress serverAddress = new InetSocketAddress(mServerName, mServerPort);
// We try to create the tunnel several times.
// TODO: The better way is to work with ConnectivityManager, trying only when the
// network is available.
// Here we just use a counter to keep things simple.
for (int attempt = 0; attempt < 10; ++attempt) {
// Reset the counter if we were connected.
if (run(serverAddress)) {
attempt = 0;
}
// Sleep for a while. This also checks if we got interrupted.
Thread.sleep(3000);
}
Log.i(getTag(), "Giving up");
} catch (IOException | InterruptedException | IllegalArgumentException e) {
Log.e(getTag(), "Connection failed, exiting", e);
}
}
private boolean run(SocketAddress server)
throws IOException, InterruptedException, IllegalArgumentException {
ParcelFileDescriptor iface = null;
boolean connected = false;
// Create a DatagramChannel as the VPN tunnel.
try (DatagramChannel tunnel = DatagramChannel.open()) {
// Protect the tunnel before connecting to avoid loopback.
if (!mService.protect(tunnel.socket())) {
throw new IllegalStateException("Cannot protect the tunnel");
}
// Connect to the server.
tunnel.connect(server);
// For simplicity, we use the same thread for both reading and
// writing. Here we put the tunnel into non-blocking mode.
tunnel.configureBlocking(false);
// Authenticate and configure the virtual network interface.
iface = handshake(tunnel);
// Now we are connected. Set the flag.
connected = true;
// Packets to be sent are queued in this input stream.
FileInputStream in = new FileInputStream(iface.getFileDescriptor());
// Packets received need to be written to this output stream.
FileOutputStream out = new FileOutputStream(iface.getFileDescriptor());
// Allocate the buffer for a single packet.
ByteBuffer packet = ByteBuffer.allocate(MAX_PACKET_SIZE);
// Timeouts:
// - when data has not been sent in a while, send empty keepalive messages.
// - when data has not been received in a while, assume the connection is broken.
long lastSendTime = System.currentTimeMillis();
long lastReceiveTime = System.currentTimeMillis();
// We keep forwarding packets till something goes wrong.
while (true) {
// Assume that we did not make any progress in this iteration.
boolean idle = true;
// Read the outgoing packet from the input stream.
int length = in.read(packet.array());
if (length > 0) {
// Write the outgoing packet to the tunnel.
packet.limit(length);
tunnel.write(packet);
packet.clear();
// There might be more outgoing packets.
idle = false;
lastReceiveTime = System.currentTimeMillis();
}
// Read the incoming packet from the tunnel.
length = tunnel.read(packet);
if (length > 0) {
// Ignore control messages, which start with zero.
if (packet.get(0) != 0) {
// Write the incoming packet to the output stream.
out.write(packet.array(), 0, length);
}
packet.clear();
// There might be more incoming packets.
idle = false;
lastSendTime = System.currentTimeMillis();
}
// If we are idle or waiting for the network, sleep for a
// fraction of time to avoid busy looping.
if (idle) {
Thread.sleep(IDLE_INTERVAL_MS);
final long timeNow = System.currentTimeMillis();
if (lastSendTime + KEEPALIVE_INTERVAL_MS <= timeNow) {
// We are receiving for a long time but not sending.
// Send empty control messages.
packet.put((byte) 0).limit(1);
for (int i = 0; i < 3; ++i) {
packet.position(0);
tunnel.write(packet);
}
packet.clear();
lastSendTime = timeNow;
} else if (lastReceiveTime + RECEIVE_TIMEOUT_MS <= timeNow) {
// We are sending for a long time but not receiving.
throw new IllegalStateException("Timed out");
}
}
}
} catch (SocketException e) {
Log.e(getTag(), "Cannot use socket", e);
} finally {
if (iface != null) {
try {
iface.close();
} catch (IOException e) {
Log.e(getTag(), "Unable to close interface", e);
}
}
}
return connected;
}
private ParcelFileDescriptor handshake(DatagramChannel tunnel)
throws IOException, InterruptedException {
// To build a secured tunnel, we should perform mutual authentication
// and exchange session keys for encryption. To keep things simple in
// this demo, we just send the shared secret in plaintext and wait
// for the server to send the parameters.
// Allocate the buffer for handshaking. We have a hardcoded maximum
// handshake size of 1024 bytes, which should be enough for demo
// purposes.
ByteBuffer packet = ByteBuffer.allocate(1024);
// Control messages always start with zero.
packet.put((byte) 0).put(mSharedSecret).flip();
// Send the secret several times in case of packet loss.
for (int i = 0; i < 3; ++i) {
packet.position(0);
tunnel.write(packet);
}
packet.clear();
// Wait for the parameters within a limited time.
for (int i = 0; i < MAX_HANDSHAKE_ATTEMPTS; ++i) {
Thread.sleep(IDLE_INTERVAL_MS);
// Normally we should not receive random packets. Check that the first
// byte is 0 as expected.
int length = tunnel.read(packet);
if (length > 0 && packet.get(0) == 0) {
return configure(new String(packet.array(), 1, length - 1, US_ASCII).trim());
}
}
throw new IOException("Timed out");
}
private ParcelFileDescriptor configure(String parameters) throws IllegalArgumentException {
// Configure a builder while parsing the parameters.
VpnService.Builder builder = mService.new Builder();
for (String parameter : parameters.split(" ")) {
String[] fields = parameter.split(",");
try {
switch (fields[0].charAt(0)) {
case 'm':
builder.setMtu(Short.parseShort(fields[1]));
break;
case 'a':
builder.addAddress(fields[1], Integer.parseInt(fields[2]));
break;
case 'r':
builder.addRoute(fields[1], Integer.parseInt(fields[2]));
break;
case 'd':
builder.addDnsServer(fields[1]);
break;
case 's':
builder.addSearchDomain(fields[1]);
break;
}
} catch (NumberFormatException e) {
throw new IllegalArgumentException("Bad parameter: " + parameter);
}
}
// Create a new interface using the builder and save the parameters.
final ParcelFileDescriptor vpnInterface;
synchronized (mService) {
vpnInterface = builder
.setSession(mServerName)
.setConfigureIntent(mConfigureIntent)
.establish();
if (mOnEstablishListener != null) {
mOnEstablishListener.onEstablish(vpnInterface);
}
}
Log.i(getTag(), "New interface: " + vpnInterface + " (" + parameters + ")");
return vpnInterface;
}
private final String getTag() {
return ToyVpnConnection.class.getSimpleName() + "[" + mConnectionId + "]";
}
}
我的VPN服务：
package com.example.android.toyvpn;
import android.app.Notification;
import android.app.PendingIntent;
import android.app.Service;
import android.content.Intent;
import android.content.SharedPreferences;
import android.net.VpnService;
import android.os.Handler;
import android.os.Message;
import android.os.ParcelFileDescriptor;
import android.util.Log;
import android.util.Pair;
import android.widget.Toast;
import java.io.IOException;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.AtomicReference;
public class ToyVpnService extends VpnService implements Handler.Callback {
private static final String TAG = ToyVpnService.class.getSimpleName();
public static final String ACTION_CONNECT = "com.example.android.toyvpn.START";
public static final String ACTION_DISCONNECT = "com.example.android.toyvpn.STOP";
private Handler mHandler;
private static class Connection extends Pair<Thread, ParcelFileDescriptor> {
public Connection(Thread thread, ParcelFileDescriptor pfd) {
super(thread, pfd);
}
}
private final AtomicReference<Thread> mConnectingThread = new AtomicReference<>();
private final AtomicReference<Connection> mConnection = new AtomicReference<>();
private AtomicInteger mNextConnectionId = new AtomicInteger(1);
private PendingIntent mConfigureIntent;
@Override
public void onCreate() {
// The handler is only used to show messages.
if (mHandler == null) {
mHandler = new Handler(this);
}
// Create the intent to "configure" the connection (just start ToyVpnClient).
mConfigureIntent = PendingIntent.getActivity(this, 0, new Intent(this, ToyVpnClient.class),
PendingIntent.FLAG_UPDATE_CURRENT);
}
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
if (intent != null && ACTION_DISCONNECT.equals(intent.getAction())) {
disconnect();
return START_NOT_STICKY;
} else {
connect();
return START_STICKY;
}
}
@Override
public void onDestroy() {
disconnect();
}
@Override
public boolean handleMessage(Message message) {
Toast.makeText(this, message.what, Toast.LENGTH_SHORT).show();
if (message.what != R.string.disconnected) {
updateForegroundNotification(message.what);
}
return true;
}
private void connect() {
// Become a foreground service. Background services can be VPN services too, but they can
// be killed by background check before getting a chance to receive onRevoke().
updateForegroundNotification(R.string.connecting);
mHandler.sendEmptyMessage(R.string.connecting);
// Extract information from the shared preferences.
final SharedPreferences prefs = getSharedPreferences(ToyVpnClient.Prefs.NAME, MODE_PRIVATE);
final String server = prefs.getString(ToyVpnClient.Prefs.SERVER_ADDRESS, "");
final byte[] secret = prefs.getString(ToyVpnClient.Prefs.SHARED_SECRET, "").getBytes();
final int port;
try {
port = Integer.parseInt(prefs.getString(ToyVpnClient.Prefs.SERVER_PORT, ""));
} catch (NumberFormatException e) {
Log.e(TAG, "Bad port: " + prefs.getString(ToyVpnClient.Prefs.SERVER_PORT, null), e);
return;
}
// Kick off a connection.
startConnection(new ToyVpnConnection(
this, mNextConnectionId.getAndIncrement(), server, port, secret));
}
private void startConnection(final ToyVpnConnection connection) {
// Replace any existing connecting thread with the new one.
final Thread thread = new Thread(connection, "ToyVpnThread");
setConnectingThread(thread);
// Handler to mark as connected once onEstablish is called.
connection.setConfigureIntent(mConfigureIntent);
connection.setOnEstablishListener(new ToyVpnConnection.OnEstablishListener() {
public void onEstablish(ParcelFileDescriptor tunInterface) {
mHandler.sendEmptyMessage(R.string.connected);
mConnectingThread.compareAndSet(thread, null);
setConnection(new Connection(thread, tunInterface));
}
});
thread.start();
}
private void setConnectingThread(final Thread thread) {
final Thread oldThread = mConnectingThread.getAndSet(thread);
if (oldThread != null) {
oldThread.interrupt();
}
}
private void setConnection(final Connection connection) {
final Connection oldConnection = mConnection.getAndSet(connection);
if (oldConnection != null) {
try {
oldConnection.first.interrupt();
oldConnection.second.close();
} catch (IOException e) {
Log.e(TAG, "Closing VPN interface", e);
}
}
}
private void disconnect() {
mHandler.sendEmptyMessage(R.string.disconnected);
setConnectingThread(null);
setConnection(null);
stopForeground(true);
}
private void updateForegroundNotification(final int message) {
startForeground(1, new Notification.Builder(this)
.setSmallIcon(R.drawable.ic_vpn)
.setContentText(getString(message))
.setContentIntent(mConfigureIntent)
.build());
}
}
上面的代码来自以下网址：
https://android.googlesource.com/platform/development/+/master/samples/ToyVpn
我已经尝试过，但没有密钥我没有得到任何解决方法。请帮忙。