/*
* Copyright (C) 2010 The Android Open Source Project
* Modifications copyright (C) 2012-2013 Saikoa / Itsana BVBA
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.android.vending.licensing;
import com.google.android.vending.licensing.util.Base64;
import com.google.android.vending.licensing.util.Base64DecoderException;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.ServiceConnection;
import android.content.pm.PackageManager.NameNotFoundException;
import android.os.Handler;
import android.os.HandlerThread;
import android.os.IBinder;
import android.os.RemoteException;
import android.provider.Settings.Secure;
import android.util.Log;
import java.security.KeyFactory;
import java.security.NoSuchAlgorithmException;
import java.security.PublicKey;
import java.security.SecureRandom;
import java.security.spec.InvalidKeySpecException;
import java.security.spec.X509EncodedKeySpec;
import java.util.Date;
import java.util.HashSet;
import java.util.LinkedList;
import java.util.Queue;
import java.util.Set;
/**
* Client library for Android Market license verifications.
* <p>
* The LicenseChecker is configured via a {@link Policy} which contains the
* logic to determine whether a user should have access to the application. For
* example, the Policy can define a threshold for allowable number of server or
* client failures before the library reports the user as not having access.
* <p>
* Must also provide the Base64-encoded RSA public key associated with your
* developer account. The public key is obtainable from the publisher site.
*/
public class LicenseChecker implements ServiceConnection {
private static final String TAG = "LicenseChecker";
private static final String KEY_FACTORY_ALGORITHM = "RSA";
// Timeout value (in milliseconds) for calls to service.
private static final int TIMEOUT_MS = 10 * 1000;
private static final SecureRandom RANDOM = new SecureRandom();
private static final boolean DEBUG_LICENSE_ERROR = false;
private ILicensingService mService;
private PublicKey mPublicKey;
private final Context mContext;
private final Policy mPolicy;
/**
* A handler for running tasks on a background thread. We don't want license
* processing to block the UI thread.
*/
private Handler mHandler;
private final String mPackageName;
private final String mVersionCode;
private final Set<LicenseValidator> mChecksInProgress = new HashSet<LicenseValidator>();
private final Queue<LicenseValidator> mPendingChecks = new LinkedList<LicenseValidator>();
/**
* @param context a Context
* @param policy implementation of Policy
* @param encodedPublicKey Base64-encoded RSA public key
* @throws IllegalArgumentException if encodedPublicKey is invalid
*/
public LicenseChecker(Context context, Policy policy, String encodedPublicKey) {
mContext = context;
mPolicy = policy;
mPublicKey = generatePublicKey(encodedPublicKey);
mPackageName = mContext.getPackageName();
mVersionCode = getVersionCode(context, mPackageName);
HandlerThread handlerThread = new HandlerThread("background thread");
handlerThread.start();
mHandler = new Handler(handlerThread.getLooper());
}
/**
* Generates a PublicKey instance from a string containing the
* Base64-encoded public key.
*
* @param encodedPublicKey Base64-encoded public key
* @throws IllegalArgumentException if encodedPublicKey is invalid
*/
private static PublicKey generatePublicKey(String encodedPublicKey) {
try {
byte[] decodedKey = Base64.decode(encodedPublicKey);
KeyFactory keyFactory = KeyFactory.getInstance(KEY_FACTORY_ALGORITHM);
return keyFactory.generatePublic(new X509EncodedKeySpec(decodedKey));
//} catch (NoSuchAlgorithmException e) {
// // This won't happen in an Android-compatible environment.
// throw new RuntimeException(e);
//} catch (Base64DecoderException e) {
// Log.e(TAG, "Could not decode from Base64.");
// throw new IllegalArgumentException(e);
//} catch (InvalidKeySpecException e) {
// Log.e(TAG, "Invalid key specification.");
// throw new IllegalArgumentException(e);
} catch (Exception e) {
throw new IllegalArgumentException(e);
}
}
/**
* Checks if the user should have access to the app. Binds the service if necessary.
* <p>
* NOTE: We can let DexGuard obfuscate the string that is passed into bindService.
* <p>
* source string: "com.android.vending.licensing.ILicensingService"
* <p>
* @param callback
*/
public synchronized void checkAccess(LicenseCheckerCallback callback) {
// If we have a valid recent LICENSED response, we can skip asking
// Market.
if (mPolicy.allowAccess()) {
Log.i(TAG, "Using cached license response");
callback.allow(Policy.LICENSED);
} else {
LicenseValidator validator = new LicenseValidator(mPolicy, new NullDeviceLimiter(),
callback, generateNonce(), mPackageName, mVersionCode);
if (mService == null) {
Log.i(TAG, "Binding to licensing service.");
try {
boolean bindResult = mContext
.bindService(
new Intent("com.android.vending.licensing.ILicensingService"),
this, // ServiceConnection.
Context.BIND_AUTO_CREATE);
if (bindResult) {
mPendingChecks.offer(validator);
} else {
Log.e(TAG, "Could not bind to service.");
handleServiceConnectionError(validator);
}
} catch (/* SecurityException */ Exception e) {
callback.applicationError(LicenseCheckerCallback.ERROR_MISSING_PERMISSION);
}
} else {
mPendingChecks.offer(validator);
runChecks();
}
}
}
private void runChecks() {
LicenseValidator validator;
while ((validator = mPendingChecks.poll()) != null) {
try {
Log.i(TAG, "Calling checkLicense on service for " + validator.getPackageName());
mService.checkLicense(
validator.getNonce(), validator.getPackageName(),
new ResultListener(validator));
mChecksInProgress.add(validator);
} catch (RemoteException e) {
Log.w(TAG, "RemoteException in checkLicense call.", e);
handleServiceConnectionError(validator);
}
}
}
private synchronized void finishCheck(LicenseValidator validator) {
mChecksInProgress.remove(validator);
if (mChecksInProgress.isEmpty()) {
cleanupService();
}
}
private class ResultListener extends ILicenseResultListener.Stub {
private final LicenseValidator mValidator;
private Runnable mOnTimeout;
public ResultListener(LicenseValidator validator) {
mValidator = validator;
mOnTimeout = new Runnable() {
public void run() {
Log.i(TAG, "Check timed out.");
handleServiceConnectionError(mValidator);
finishCheck(mValidator);
}
};
startTimeout();
}
private static final int ERROR_CONTACTING_SERVER = 0x101;
private static final int ERROR_INVALID_PACKAGE_NAME = 0x102;
private static final int ERROR_NON_MATCHING_UID = 0x103;
// Runs in IPC thread pool. Post it to the Handler, so we can guarantee
// either this or the timeout runs.
public void verifyLicense(final int responseCode, final String signedData,
final String signature) {
mHandler.post(new Runnable() {
public void run() {
Log.i(TAG, "Received response.");
// Make sure it hasn't already timed out.
if (mChecksInProgress.contains(mValidator)) {
clearTimeout();
mValidator.verify(mPublicKey, responseCode, signedData, signature);
finishCheck(mValidator);
}
if (DEBUG_LICENSE_ERROR) {
boolean logResponse;
String stringError = null;
switch (responseCode) {
case ERROR_CONTACTING_SERVER:
logResponse = true;
stringError = "ERROR_CONTACTING_SERVER";
break;
case ERROR_INVALID_PACKAGE_NAME:
logResponse = true;
stringError = "ERROR_INVALID_PACKAGE_NAME";
break;
case ERROR_NON_MATCHING_UID:
logResponse = true;
stringError = "ERROR_NON_MATCHING_UID";
break;
default:
logResponse = false;
}
if (logResponse) {
String android_id = Secure.getString(mContext.getContentResolver(),
Secure.ANDROID_ID);
Date date = new Date();
Log.d(TAG, "Server Failure: " + stringError);
Log.d(TAG, "Android ID: " + android_id);
Log.d(TAG, "Time: " + date.toGMTString());
}
}
}
});
}
private void startTimeout() {
Log.i(TAG, "Start monitoring timeout.");
mHandler.postDelayed(mOnTimeout, TIMEOUT_MS);
}
private void clearTimeout() {
Log.i(TAG, "Clearing timeout.");
mHandler.removeCallbacks(mOnTimeout);
}
}
public synchronized void onServiceConnected(ComponentName name, IBinder service) {
mService = ILicensingService.Stub.asInterface(service);
runChecks();
}
public synchronized void onServiceDisconnected(ComponentName name) {
// Called when the connection with the service has been
// unexpectedly disconnected. That is, Market crashed.
// If there are any checks in progress, the timeouts will handle them.
Log.w(TAG, "Service unexpectedly disconnected.");
mService = null;
}
/**
* Generates policy response for service connection errors, as a result of
* disconnections or timeouts.
*/
private synchronized void handleServiceConnectionError(LicenseValidator validator) {
mPolicy.processServerResponse(Policy.RETRY, null);
if (mPolicy.allowAccess()) {
validator.getCallback().allow(Policy.RETRY);
} else {
validator.getCallback().dontAllow(Policy.RETRY);
}
}
/** Unbinds service if necessary and removes reference to it. */
private void cleanupService() {
if (mService != null) {
try {
mContext.unbindService(this);
} catch (IllegalArgumentException e) {
// Somehow we've already been unbound. This is a non-fatal
// error.
Log.e(TAG, "Unable to unbind from licensing service (already unbound)");
}
mService = null;
}
}
/**
* Inform the library that the context is about to be destroyed, so that any
* open connections can be cleaned up.
* <p>
* Failure to call this method can result in a crash under certain
* circumstances, such as during screen rotation if an Activity requests the
* license check or when the user exits the application.
*/
public synchronized void onDestroy() {
cleanupService();
mHandler.getLooper().quit();
}
/** Generates a nonce (number used once). */
private int generateNonce() {
return RANDOM.nextInt();
}
/**
* Get version code for the application package name.
*
* @param context
* @param packageName application package name
* @return the version code or empty string if package not found
*/
private static String getVersionCode(Context context, String packageName) {
try {
return String.valueOf(context.getPackageManager().getPackageInfo(packageName, 0).
versionCode);
} catch (/* NameNotFoundException */ Exception e) {
Log.e(TAG, "Package not found. could not get version code.");
return "";
}
}
}