28 Apr 2016

feedAndroid Developers Blog

Enhancing App Security on Google Play

Posted by Eric Davis, Android Security Team

We're constantly investing in new tools and services to help developers build secure Android applications. This includes the application sandbox and Security APIs in the platform, Security APIs in Google Play Services, and even open source testing tools. Last year, Google Play also helped developers enhance the security of their applications by looking directly at the code they've written and offering suggestions for improvements.

The Google Play App Security Improvement Program is the first of its kind. It has two core components: We provide developers with security tips to help them build more secure apps, and we help developers identify potential security enhancements when uploaded to Google Play. This week, to help educate developers, Kristian Monsen, one of our engineers, gave a presentation about security best practices at the Samsung Developer Conference. And in 2015, we worked with developers to improve the security of over 100,000 apps through the program.

How it works

Before any app is accepted into Google Play, it is scanned for safety and security, including potential security issues. We also continuously re-scan the over one million apps in Google Play for additional threats.

If your app is flagged for a potential security issue, you will be notified immediately to help you quickly address the issue and help keep your users safe. We'll deliver alerts to you using both email and the Google Play Developer Console, with links to a support page with details about how to improve the app.


Typically, these notifications will include a timeline for delivering the improvement to users as quickly as possible. Applications may be required to make security improvements before any other app updates can be be published.

You can confirm that you've fully addressed the issue by uploading the new version of your app to the Google Play Developer Console. Be sure to increment the version number of the fixed app. After a few hours, check the Developer Console for the security alert; if it's no longer there, you're all set!

The success of this program rests on our partnership with you-the developers of apps on Google Play-and the security community. We're all responsible for providing safe, secure apps to our users. For feedback or questions, please reach out to us through the Google Play Developer Help Center. To report potential security issues in apps, please reach out to us at security+asi@android.com.

28 Apr 2016 9:08pm GMT

27 Apr 2016

feedAndroid Developers Blog

Developing for Direct Boot

Posted by Wojtek Kaliciński, Developer Advocate

Starting with Android N, a device that has been powered on can boot into a new mode called Direct Boot before the user has a chance to unlock it for the first time. In this mode, the operating system is fully operational, but access to private app data is limited and only apps that have been updated to be Direct Boot aware can run.

Is Direct Boot right for my app?

Not every app should run in Direct Boot mode, so before you start coding check if your app fits these common use cases:

Please note that this is not an exhaustive list and we look forward to seeing what other kinds of apps can benefit from Direct Boot.

Making your app Direct Boot aware

In order to let your app run before the user unlocks the device, you have to explicitly mark components as being Direct Boot aware in the manifest:

 <activity|provider|receiver|service ...  
     android:directBootAware="true">  

You can pick the subset of your app components that need to be Direct Boot aware, but if you are using a custom Application class, it is assumed to be Direct Boot aware if any component inside your app is marked as Direct Boot aware.

For apps that need to run as soon as the system starts in Direct Boot mode, there is a new Intent.ACTION_LOCKED_BOOT_COMPLETED broadcast. All apps will still receive Intent.ACTION_BOOT_COMPLETED after the user unlocks the device.

Using the device protected storage area

To support running apps before the user provides the credentials needed to unlock private app data, all Android N devices now provide two storage locations for data:

Components of your app that are marked as Direct Boot aware must rely on device protected storage for any data required for their operation during Direct Boot mode. They may still access credential protected storage after the user has unlocked the device.

To access device protected storage you need to create and use a secondary Context object for all file-related APIs:

 Context deviceProtectedContext = context.createDeviceProtectedStorageContext();  
 deviceProtectedContext.openFileInput( ... )  

When your app gets updated to a Direct Boot aware version, you might have previously saved Shared Preferences or databases that need to be migrated to device protected storage. You should use Context.moveSharedPreferencesFrom() and Context.moveDatabaseFrom() before accessing them to make sure the app continues to work properly even when data is backed up and restored from older versions or other devices.

Things to watch out for

You should think carefully about what you put in the device protected storage. This should be a minimum set of data that will let your app work during Direct Boot. For example, in a messaging app you could store an access token with a narrow scope that only has access to the number of new messages on your server. All sensitive, private information, like the full message history and a read/write access token, should still be saved in credential protected storage.

Another thing to remember is that during Direct Boot apps can only access other Direct Boot aware apps and components. If your app depends on external Services and Activities, make sure you gracefully handle the situation when they're not available. Intent filters will by default match only components available in the current user state (locked / unlocked). There are two new flags for explicitly telling the Package Manager which components to enumerate: PackageManager.MATCH_DIRECT_BOOT_AWARE and PackageManager.MATCH_DIRECT_BOOT_UNAWARE.

What's next?

Until devices with Android N that support Direct Boot out of the box are released, you can test your apps using Android N Developer Preview builds. On Nexus 5X and Nexus 6P, you can wipe all user data and enable full Direct Boot mode by using Settings > Developer options > Convert to file encryption. Alternatively, you can reboot into bootloader and issue the appropriate fastboot command:

 $ adb reboot-bootloader  
 $ fastboot --wipe-and-use-fbe  

Warning: Both methods will perform a factory reset and delete all user data on your device.

Alternatively, you can use an emulated Direct Boot mode. To enable it, set a lock pattern on the device, choose "No thanks" if prompted for a secure start-up screen when setting a lock pattern, and then use the following adb shell commands to enable and disable emulation:

 $ adb shell sm set-emulate-fbe true  
 $ adb shell sm set-emulate-fbe false  

Please note that using these commands will cause your device to reboot. You should only be using emulated Direct Boot mode on test devices, as it may cause data loss.

#BuildBetterApps

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27 Apr 2016 9:06pm GMT

26 Apr 2016

feedAndroid Developers Blog

Android Studio 2.1 supports Android N Developer Preview

Posted by Jamal Eason, Product Manager, Android

With the launch Android N Developer Preview, we wanted to give you an easy and comprehensive way to build, test and validate your apps on the latest release with Android Studio. Built on the speed and feature enhancements of Android Studio 2.0, the stable release of Android Studio 2.1 includes updates to the IDE wizards, build system and Android Emulator so that you can try out new features and APIs of the developer preview including the new Jack compiler and Java 8 language support. In addition to support for the N Developer Preview, Android Studio 2.1 also includes performance improvements to Instant Run which leads to faster edit and deploy build speeds. If you are developing and validating your app with the N Developer Preview or want faster Instant Run speeds, you should download or update on the stable release channel to Android Studio 2.1.

Android Studio 2.1 includes the following new features:


Deeper Dive into the New Features

N Developer Preview

On top of new features and APIs of the N Developer Preview, Android Studio 2.1 release includes support for the new Jack compiler and support for Java 8. With the Jack compiler, lambdas, method references, compile-time type annotations, intersection types and type inference are available on all versions of the Android platform. Default and static methods and repeatable annotations are available on Android N and higher. To use Java 8 language features when developing with the N Developer Preview, you need to use the Jack compiler. The New Project Wizard [File→ New→ Project] generates the correct configurations for projects targeting the N.

Getting started with development is as easy generating a new project or updating a few settings in your existing project. Once you are ready to test, you can create a fresh Android Virtual Device (AVD) and run your app on the N Developer Preview using the new Android Emulator.


N Developer Preview on the new Android Emulator


Instant Run & General Build Performance Improvements

Instant Run and general build speed are now faster with two new features: incremental Java compilation and in-process dex.

In previous versions of Android Studio, a single line of Java code change will cause all the Java sources in the module to be recompiled. Now in Android Studio 2.1, incremental Java compilation is enabled by default to reduce compilation time by compiling only what is needed.

We are also speeding up build times by using in-process dex, which converts class files to dex files within the Gradle daemon process. This avoids the costly processing operation of creating separate dex processes. To use this feature, you will need to increase the amount of memory available to the Gradle daemon to at least 2GB (1 GB is the default). This feature will help speed up both incremental and full builds.

We'd appreciate your feedback as we continue to improve Instant Run and general build performance. We are going to keep working on making build times even faster in coming releases. Click here to learn even more about the build changes.

What's Next

Update

If you are using a previous version of Android Studio, you can check for updates on the Stable channel from the navigation menu (Help → Check for Update [Windows/Linux] , Android Studio → Check for Updates [OS X]). If you need a new copy of Android Studio, you can download it here.

Test and Validate Apps with N Developer Preview

After you update to or download Android Studio 2.1 and you want to test and develop your apps with the N Developer Preview, create a fresh Android Virtual Device (AVD) for the new Android emulator, and check out these additional setup instructions.

We appreciate any feedback on things you like, issues or features you would like to see. Connect with us -- the Android Studio development team -- on our Google+ page or on Twitter.

26 Apr 2016 9:49pm GMT