Tag Archives: Develop

Cryptography Changes in Android P

Posted by Adam Vartanian, Software Engineer

We hope you're enjoying the first developer preview of Android P. We wanted to specifically call out some backward-incompatible changes we plan to make to the cryptographic capabilities in Android P, which you can see in the developer preview.

Changes to providers

Starting in Android P, we plan to deprecate some functionality from the BC provider that's duplicated by the AndroidOpenSSL (also known as Conscrypt) provider. This will only affect applications that specify the BC provider explicitly when calling getInstance() methods. To be clear, we aren't doing this because we are concerned about the security of the implementations from the BC provider, rather because having duplicated functionality imposes additional costs and risks while not providing much benefit.

If you don't specify a provider in your getInstance() calls, no changes are required.

If you specify the provider by name or by instance—for example, Cipher.getInstance("AES/CBC/PKCS7PADDING", "BC") or Cipher.getInstance("AES/CBC/PKCS7PADDING", Security.getProvider("BC"))—the behavior you get in Android P will depend on what API level your application targets. For apps targeting an API level before P, the call will return the BC implementation and log a warning in the application log. For apps targeting Android P or later, the call will throw NoSuchAlgorithmException.

To resolve this, you should stop specifying a provider and use the default implementation.

In a later Android release, we plan to remove the deprecated functionality from the BC provider entirely. Once removed, any call that requests that functionality from the BC provider (whether by name or instance) will throw NoSuchAlgorithmException.

Removal of the Crypto provider

In a previous post, we announced that the Crypto provider was deprecated beginning in Android Nougat. Since then, any request for the Crypto provider by an application targeting API 23 (Marshmallow) or before would succeed, but requests by applications targeting API 24 (Nougat) or later would fail. In Android P, we plan to remove the Crypto provider entirely. Once removed, any call to SecureRandom.getInstance("SHA1PRNG", "Crypto") will throw NoSuchProviderException. Please ensure your apps have been updated.

Previewing Android P

Posted by Dave Burke, VP of Engineering

Last week at Mobile World Congress we saw that Android's ecosystem of developers, device makers, and silicon partners continues to bring amazing experiences to users worldwide.

Looking ahead, today we're sharing the first developer preview of Android P, the newest version of Android. It's an early baseline build for developers only -- you're our most trusted reviewers and testers ;-) Early feedback from our developer community is crucial in helping us evolve the platform to meet your needs. We'd love to get you started exercising the new features and APIs in P, and as always, we depend on your early feedback and ideas, so please give us your input!

This first developer preview of Android P is just the start - we'll have lots more to share at Google I/O in May, stay tuned!

New features to try in your apps

Here's a look at some of the cool features in this first preview of Android P that we want you to try and give feedback on.

Indoor positioning with Wi-Fi RTT

Accurate indoor positioning has been a long-standing challenge that opens new opportunities for location-based services. Android P adds platform support for the IEEE 802.11mc WiFi protocol -- also known as WiFi Round-Trip-Time (RTT) -- to let you take advantage of indoor positioning in your apps.

On Android P devices with hardware support, location permission, and location enabled, your apps can use RTT APIs to measure the distance to nearby WiFi Access Points (APs). The device doesn't need to connect to the APs to use RTT, and to maintain privacy, only the phone is able to determine the distance, not the APs.

Knowing the distance to 3 or more APs, you can calculate the device position with an accuracy of 1 to 2 meters. With this accuracy, you can build new experiences like in-building navigation; fine-grained location-based services such as disambiguated voice control (e.g.,'Turn on this light'); and location-based information (e.g., 'Are there special offers for this product?').

Display cutout support

Now apps can take full advantage of the latest device screens with fullscreen content. We've added display cutout into the platform, along with APIs that you can use to manage how your content is displayed.

Cutout support works seamlessly for apps, with the system managing status bar height to separate your content from the cutout. If you have critical, immersive content, you can also use new APIs to check the cutout shape and request full-screen layout around it. You can check whether the current device has a cutout by calling getDisplayCutout(), and then determine the location and shape of the cutout area using DisplayCutout. A new window layout attribute, layoutInDisplayCutoutMode, lets you tell the system how and when lay out your content relative to the cutout area. Details are here.

To make it easier to build and test cutout support in your app, we've added a Developer Option that simulates a cutout on any device. We recommend testing your existing apps with display cutout enabled to ensure that your content displays properly.

Apps with immersive content can display content fullscreen on devices with a display cutout.

Improved messaging notifications

In Android P we've put a priority on improving visibility and function in notifications. Try the new MessagingStyle notification style -- it highlights who is messaging and how you can reply. You can show conversations, attach photos and stickers, and even suggest smart replies. See the details here.

In MessagingStyle notifications you can now show conversations and smart replies [left] and even attach images and stickers [right].

Multi-camera API

You can now access streams simultaneously from two or more physical cameras on devices running Android P. On devices with either dual-front or dual-back cameras, you can create innovative features not possible with just a single camera, such as seamless zoom, bokeh, and stereo vision. The API also lets you call a logical or fused camera stream that automatically switches between two or more cameras. We're looking forward to seeing your new and exciting creations as Android P devices supporting multiple cameras reach the market in the year ahead.

Other improvements in camera include new Session parameters that help to reduce delays during initial capture, and Surface sharing that lets camera clients handle various use-cases without the need to stop and start camera streaming. We've also added APIs for display-based flash support and access to OIS timestamps for app-level image stabilization and special effects.

ImageDecoder for bitmaps and drawables

Android P gives you an easier way to decode images to bitmaps or drawables -- ImageDecoder, which deprecates BitmapFactory. ImageDecoder lets you create a bitmap or drawable from a byte buffer, file, or URI. It offers several advantages over BitmapFactory, including support for exact scaling, single-step decoding to hardware memory, support for post-processing in decode, and decoding of animated images.

You can decode and scale to an exact size just by calling setResize() with the target dimensions. You can also call getSampledSize() to get the image dimensions at a specific sample rate, then scale to those dimensions. If you want post-process an image -- such as applying rounded corners for circle masks or more complicated effects -- you can pass ImageDecoder any android.graphics.PostProcessor. You can also create Drawables directly, with ImageDecoder.decodeDrawable(). If the encoded image is an animated GIF or WebP, the Drawable will be an instance of the new AnimatedImageDrawable.

HDR VP9 Video, HEIF image compression, and Media APIs

Android P adds built-in support for HDR VP9 Profile 2, so you can now deliver HDR-enabled movies to your users from YouTube, Play Movies, and other sources on HDR-capable devices.

We're excited to add HEIF (heic) image encoding to the platform. HEIF is a popular format for photos that improves compression to save on storage and network data. With platform support on Android P devices, it's easy to send and utilize HEIF images from your backend server. Once you've made sure that your app is compatible with this data format for sharing and display, give HEIF a try as an image storage format in your app. You can do a jpeg-to-heic conversion using ImageDecoder or BitmapFactory to obtain a bitmap from jpeg, and you can use HeifWriter in the new Support Library alpha to write HEIF still images from YUV byte buffer, Surface, or Bitmap.

We're also in the process of enhancing and refactoring the media APIs to make them easier to develop and integrate with -- watch for details coming later this year.

Data cost sensitivity in JobScheduler

JobScheduler is Android's central service to help you manage scheduled tasks or work across Doze, App Standby, and Background Limits changes. In Android P, JobScheduler handles network-related jobs better for the user, coordinating with network status signals provided separately by carriers.

Jobs can now declare their estimated data size, signal prefetching, and specify detailed network requirements—carriers can report networks as being congested or unmetered. JobScheduler then manages work according to the network status. For example, when a network is congested, JobScheduler might defer large network requests. When unmetered, it can run prefetch jobs to improve the user experience, such as by prefetching headlines.

When you are adding jobs, try using setEstimatedNetworkBytes(), setIsPrefetch() and setRequiredNetwork() to let JobScheduler handle the work properly. When your job executes, be sure to use the Network object returned by JobParameters.getNetwork(), otherwise you'll implicitly use the device's default network which may not meet your requirements, causing unintended data usage.

Neural Networks API 1.1

We introduced the Neural Networks API in Android 8.1 to accelerate on-device machine learning on Android. In Android P we're expanding and improving this API, adding support for nine new ops -- Pad, BatchToSpaceND, SpaceToBatchND, Transpose, Strided Slice, Mean, Div, Sub, and Squeeze. If you have a Pixel 2 device, the DP1 build now includes an Qualcomm Hexagon HVX driver with acceleration for quantized models.

Autofill improvements

In Android P we're continuing to improve the Autofill Framework based on feedback from users and developers. Along with key bugfixes, this release includes new APIs that allow password managers to improve the Autofill user experience, such as better dataset filtering, input sanitization, and compatibility mode. Compatibility mode in particular has a high impact on end users because it lets password managers take the accessibility-based approach in apps that don't yet have full Autofill support, but without impacts on performance or security. See all the details on what's new here.

Open Mobile API for NFC payments and secure transactions

Android P adds an implementation of the GlobalPlatform Open Mobile API to Android. On supported devices, apps can use the OMAPI API to access secure elements (SE) to enable smart-card payments and other secure services. A hardware abstraction layer (HAL) provides the underlying API for enumerating a variety of Secure Elements (eSE, UICC, and others) available.

Strengthening Android's foundations

In Android P we're continuing our long-term investment to make Android the best platform for developers.

Security for apps

In Android P we're moving to a more consistent UI for fingerprint authentication across apps and devices. Android now provides a standard system dialog to prompt the user to touch the fingerprint sensor, managing text and placement as appropriate for the device. Apps can trigger the system fingerprint dialog using a new FingerprintDialog API. We recommend switching to the new system dialog as soon as possible.

As part of a larger effort to move all network traffic away from cleartext (unencrypted HTTP) to TLS, we're also changing the defaults for Network Security Configuration to block all cleartext traffic. If you are using a Network Security Configuration, you'll now need to make connections over TLS, unless you explicitly opt-in to cleartext for specific domains.

Privacy for users

To better ensure privacy, Android P restricts access to mic, camera, and all SensorManager sensors from apps that are idle. While your app's UID is idle, the mic reports empty audio and sensors stop reporting events. Cameras used by your app are disconnected and will generate an error if the app tries to use them. In most cases, these restrictions should not introduce new issues for existing apps, but we recommend removing these requests from your apps.

We will also enable encryption of Android backups with a client-side secret. This feature is still in active development and will be launched in a future Android P preview release.

Longer term we're working to bring support for per-network randomization of associated MAC addresses to the platform. On supported devices running Android P, you can enable this experimentally for testing as a new developer option.

Android P also gives the user control over access to the platform's build.serial identifier by putting it behind the READ_PHONE_STATE permission. Direct access to this identifier has been deprecated since Android 8.0. In order to access the build.serial identifier, you should use the Build.getSerial() method.

ART performance

We're working to bringing performance and efficiency improvements to all apps through the ART runtime. We've expanded ART's use of execution profiles to optimize apps and reduce in-memory footprint of compiled app code. ART now uses profile information for on-device rewriting of DEX files, with reductions up to 11% across a range of popular apps. We expect these to correlate closely with reductions in system DEX memory usage and faster startup times for your apps.

Optimized Kotlin

Kotlin is a first-class language on Android, and if you haven't tried it yet, you should! We've made an enduring commitment to Kotlin in Android and continue to expand support including optimizing the performance of Kotlin code. In P you'll see the first results of this work -- we've improved several compiler optimizations, especially those that target loops, to extract better performance. We're also continuing to work in partnership with JetBrains to optimize Kotlin's generated code. You can get all of the latest Kotlin performance improvements just by keeping Android Studio's Kotlin plugin up-to-date.

Power efficiency

In Android P we continue to refine Doze, App Standby, and Background Limits to further improve battery life; please be sure to try your apps with these and send feedback.

Targeting modern Android

Android P is shaped by our longer-term initiatives to modernize the foundations of Android and the apps that run on it. As we announced recently, Google Play will require all app updates to target Android Oreo (targetSdkVersion 26 or higher) by November 2018, with support for 64-bit hardware on the horizon for 2019.

In line with these changes, Android P will warn users with a dialog when they install an app that targets a platform earlier than Android 4.2 (targetSdkVersion less than 17), and future platform versions will continue to increment that lower bound. We're encouraging every Android developer to start planning the migration to target API 26 now, and to start the migration work as soon as possible. Here's a checklist of resources for help and support -- we're looking forward to seeing your apps getting the most from modern Android.

Improving app compatibility through public APIs

A key issue for users and developers is app compatibility -- making sure that apps are ready for new platform versions as they arrive, without risk of crashes for users and emergency rollouts for developers. Apps that use Android's public APIs from the SDK or NDK are in a good position to be compatible, but apps that use private Android interfaces and libraries are not.

So with Android P we're starting a gradual process to restrict access to selected non-SDK interfaces, asking developers -- including app teams inside Google -- to use the public equivalents instead. In cases where there is no public equivalent for your use-case, please let us know -- we want to make sure that this process is as smooth as possible for developers, so we'll use your feedback to ensure the initial rollout only affects APIs where developers can easily migrate to public alternatives. More about the restrictions is here.

Get started in a few simple steps

First, make your app compatible to give your users a seamless transition to Android P. Just download a device system image or emulator system image, install your current app, and test -- the app should run and look great, and handle behavior changes properly. After you've made any necessary updates, we recommend publishing to Google Play right away without changing the app's platform targeting.

Remember, you don't need a supported Pixel device to test or develop on Android P. For most uses we highly recommend setting up an Android Virtual Device on the Android Emulator as a test environment instead. If you haven't tried the emulator recently, you'll find that it's incredibly fast , boots in under 6 seconds, convenient to use, and you can even model next-gen screens -- such as long screens and screens with camera cutout.

Next, change your app's targeting to "P" and run it with the full Android P experience. Set your app's targetSdkVersion to 'P' and compileSdkVersion to android-P, build, and test. Make sure to read the behavior changes for apps targeting P to find areas you will want to test and might need to adjust.

When you're ready, dive into Android P and learn about the many new features and APIs you can take advantage of in your app. To make it easier to explore the new APIs, take a look at the API diff report, along with the Android P API reference. Visit the P Developer Preview site for details on the preview timeline and support resources. Also check out this video highlighting what's new in Android P for developers.

To get started building with Android P, download the P Developer Preview SDK and tools into Android Studio 3.1 or use the latest Android Studio 3.2 canary version. We're also releasing an alpha version of the 28.0.0 support library for you to try.

What's ahead?

The Android P Developer Preview includes an updated SDK with system images for testing on the official Android Emulator and on Pixel, Pixel XL Pixel 2, and Pixel 2 XL devices.

We plan to update the preview system images and SDK regularly throughout the preview. This initial release is for developers only and not intended for daily or consumer use, so we're making it available by manual download and flash only. Downloads and instructions are here.

As we get closer to a final product, we'll be inviting consumers to try it out as well, and we'll open up enrollments through Android Beta at that time. Stay tuned for details, but for now please note that Android Beta is not currently available for Android P.

As always, your feedback is critical, so please let us know what you think — the sooner we hear from you, the more of your feedback we can integrate. When you find issues, please report them here. We have separate hotlists for filing platform issues, app compatibility issues, and third-party SDK issues.

Android Developer Story: Big Fish Games uses open beta testing to de-risk their game launch

Posted by Kacey Fahey, Developer Marketing, Google Play

Based in Seattle, Big Fish Games was founded in 2002. Starting as a game studio, they quickly turned into a major publisher and distributor of casual games. Leading up to the launch of their hit time management game, Cooking Craze, the team ran an open beta on Google Play.

Big Fish Games found that using open beta provided more than 10x the amount of user feedback from around the world, and also gave them access to key metrics and Android Vitals in the Play Console. The ability to monitor game performance metrics pre-launch allowed the team to focus on areas of improvement, which lead to a 21% reduction in crash rate. The larger sample size of beta testers also provided more insights on player behavior and helped achieve a +7% improvement in day 1, day 7, and day 30 retention rates.

You can also learn more pre-launch best practices and strategies to improve performance post-launch at our Google Developer Day on Monday, March 19th at GDC. Sign up to stay informed.

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Android Excellence: congratulations to the newly added apps and games

Posted by Kacey Fahey, Developer Marketing, Google Play

Kicking off the new year, we're excited to welcome our latest group of Android Excellence apps and games. These awardees represent some of the best experiences and top performing apps and games on the Play Store and can be found with other great selections on the Editors' Choice page.

If you're looking for some new apps, below are a few highlights.

  • EyeEm: A great photo editor app with a full suite of filters and tools to make your pictures shine. Learn style tips from their community and even sell your images through the EyeEm marketplace.
  • Musixmatch: Check out Musixmatch's updated app while learning the lyrics to all your favorite songs. The app is compatible with many of the top music streaming services and you can even follow along with your Android Wear device or on the big screen with Chromecast support.
  • ViewRanger: Plan your next hiking adventure by discovering new routes and trail guides with ViewRanger. Check out the Skyline feature using your phone's camera to identify over 9 million sites across the world through augmented reality.

Here are a few of our favorite new games joining the collection.

  • Fire Emblem Heroes: Nintendo's popular strategy-RPG franchise is now reimagined for mobile. Fight battles, develop your heroes' skills, and try various gameplay modes for hours of exciting gameplay.
  • Lumino City: Explore the charming papercraft style world in this award-winning puzzle adventure game. The beautiful scenery is all handcrafted.
  • Old Man's Journey: Gorgeous scenery, an immersive soundtrack, and deep emotion help you uncover the old man's life stories while you solve puzzles and shape the landscape to determine his future.

Congratulations to the newly added Android Excellence apps and games.

New Android Excellence apps New Android Excellence games
1tap

Acorns

Airbnb

Blink Health

Blinkist

Clue

Ditty

EyeEm

Fabulous

IFTTT

iReader

Journey

KKBOX

LinkedIn

Mobills: Budget Planner

Musixmatch

Shpock

Stocard

Video Editor

ViewRanger

YAZIO

YOP

Agent A

Bit Heroes

Bloons Supermonkey 2

Dancing Line

DEAD WARFARE: Zombie

Dragon Project

Fire Emblem Heroes

Futurama: Worlds of Tomorrow

Idle Heroes

Last Day on Earth: Survival

Lords Mobile

Lumino City

Modern Combat Versus

Old Man's Journey

The Walking Dead No Man's Land

War Wings

Explore other great apps and games in the Editors' Choice section on Google Play and discover best practices to help you build quality apps and games for people to love.

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Phasing out legacy recommendations on Android TV

Posted by Bejamin Baxter, Developer Programs Engineer

At Google I/O 2017, we announced a redesign of the Android TV's home screen. We expanded the recommendation row concept so that each app can have its own row (or multiple rows) of content on the home screen. Since the release of the new home screen, we have seen increased adoption of the new recommendation channels for Android Oreo in a wide variety of apps.

With more and more apps surfacing high-quality recommendations using the new channels, the legacy recommendation row in the new home screen on Android O will be phased out over the next year.

Currently, when an app creates recommendations with the legacy notification based API the content is added to a channel for that app. The channel may already exist if there was recommended content for it when you upgraded from Android N (or below). If the there is no channel for the app, it will be automatically generated for you. In either case, the user can't add or remove programs from the channel, but they can move, hide, and show the channel. When an app starts to use the new API to add its own channels, the system removes the auto-generated channel and the app takes over control of the display of their content.

Over the next year, we will phase out the automatic generation of channels. Instead of generating multiple channels, one for each app's legacy recommendations, we will insert one channel for all legacy recommendations. This channel will appear at the bottom of the channel list. Users can move or remove it. When a user upgrades to Android O, the previous recommendation row from Android N (and below) becomes a channel at the bottom of the home screen.

If you have not updated your app to post content to the new channels on the home screen, take a look at our documentation, codelab, and sample to get started.

We look forward to more and more apps taking advantage of the new changes in the home screen. We love to hear your feedback, so please visit the Android TV Developer Community on G+ to share your thoughts and ideas.

Double Stuffed Security in Android Oreo

Posted by Gian G Spicuzza, Android Security team

Android Oreo is stuffed full of security enhancements. Over the past few months, we've covered how we've improved the security of the Android platform and its applications: from making it safer to get apps, dropping insecure network protocols, providing more user control over identifiers, hardening the kernel, making Android easier to update, all the way to doubling the Android Security Rewards payouts. Now that Oreo is out the door, let's take a look at all the goodness inside.

Expanding support for hardware security

Android already supports Verified Boot, which is designed to prevent devices from booting up with software that has been tampered with. In Android Oreo, we added a reference implementation for Verified Boot running with Project Treble, called Android Verified Boot 2.0 (AVB). AVB has a couple of cool features to make updates easier and more secure, such as a common footer format and rollback protection. Rollback protection is designed to prevent a device to boot if downgraded to an older OS version, which could be vulnerable to an exploit. To do this, the devices save the OS version using either special hardware or by having the Trusted Execution Environment (TEE) sign the data. Pixel 2 and Pixel 2 XL come with this protection and we recommend all device manufacturers add this feature to their new devices.

Oreo also includes the new OEM Lock Hardware Abstraction Layer (HAL) that gives device manufacturers more flexibility for how they protect whether a device is locked, unlocked, or unlockable. For example, the new Pixel phones use this HAL to pass commands to the bootloader. The bootloader analyzes these commands the next time the device boots and determines if changes to the locks, which are securely stored in Replay Protected Memory Block (RPMB), should happen. If your device is stolen, these safeguards are designed to prevent your device from being reset and to keep your data secure. This new HAL even supports moving the lock state to dedicated hardware.

Speaking of hardware, we've invested support in tamper-resistant hardware, such as the security module found in every Pixel 2 and Pixel 2 XL. This physical chip prevents many software and hardware attacks and is also resistant to physical penetration attacks. The security module prevents deriving the encryption key without the device's passcode and limits the rate of unlock attempts, which makes many attacks infeasible due to time restrictions.

While the new Pixel devices have the special security module, all new GMS devices shipping with Android Oreo are required to implement key attestation. This provides a mechanism for strongly attesting IDs such as hardware identifiers.

We added new features for enterprise-managed devices as well. In work profiles, encryption keys are now ejected from RAM when the profile is off or when your company's admin remotely locks the profile. This helps secure enterprise data at rest.

Platform hardening and process isolation

As part of Project Treble, the Android framework was re-architected to make updates easier and less costly for device manufacturers. This separation of platform and vendor-code was also designed to improve security. Following the principle of least privilege, these HALs run in their own sandbox and only have access to the drivers and permissions that are absolutely necessary.

Continuing with the media stack hardening in Android Nougat, most direct hardware access has been removed from the media frameworks in Oreo resulting in better isolation. Furthermore, we've enabled Control Flow Integrity (CFI) across all media components. Most vulnerabilities today are exploited by subverting the normal control flow of an application, instead changing them to perform arbitrary malicious activities with all the privileges of the exploited application. CFI is a robust security mechanism that disallows arbitrary changes to the original control flow graph of a compiled binary, making it significantly harder to perform such attacks.

In addition to these architecture changes and CFI, Android Oreo comes with a feast of other tasty platform security enhancements:

  • Seccomp filtering: makes some unused syscalls unavailable to apps so that they can't be exploited by potentially harmful apps.
  • Hardened usercopy: A recent survey of security bugs on Android revealed that invalid or missing bounds checking was seen in approximately 45% of kernel vulnerabilities. We've backported a bounds checking feature to Android kernels 3.18 and above, which makes exploitation harder while also helping developers spot issues and fix bugs in their code.
  • Privileged Access Never (PAN) emulation: Also backported to 3.18 kernels and above, this feature prohibits the kernel from accessing user space directly and ensures developers utilize the hardened functions to access user space.
  • Kernel Address Space Layout Randomization (KASLR): Although Android has supported userspace Address Space Layout Randomization (ASLR) for years, we've backported KASLR to help mitigate vulnerabilities on Android kernels 4.4 and newer. KASLR works by randomizing the location where kernel code is loaded on each boot, making code reuse attacks probabilistic and therefore more difficult to carry out, especially remotely.

App security and device identifier changes

Android Instant Apps run in a restricted sandbox which limits permissions and capabilities such as reading the on-device app list or transmitting cleartext traffic. Although introduced during the Android Oreo release, Instant Apps supports devices running Android Lollipop and later.

In order to handle untrusted content more safely, we've isolated WebView by splitting the rendering engine into a separate process and running it within an isolated sandbox that restricts its resources. WebView also supports Safe Browsing to protect against potentially dangerous sites.

Lastly, we've made significant changes to device identifiers to give users more control, including:

  • Moving the static Android ID and Widevine values to an app-specific value, which helps limit the use of device-scoped non-resettable IDs.
  • In accordance with IETF RFC 7844 anonymity profile, net.hostname is now empty and the DHCP client no longer sends a hostname.
  • For apps that require a device ID, we've built a Build.getSerial() API and protected it behind a permission.
  • Alongside security researchers1, we designed a robust MAC address randomization for Wi-Fi scan traffic in various chipsets firmware.

Android Oreo brings in all of these improvements, and many more. As always, we appreciate feedback and welcome suggestions for how we can improve Android. Contact us at [email protected].

_____________________________________________________________________

1: Glenn Wilkinson and team at Sensepost, UK, Célestin Matte, Mathieu Cunche: University of Lyon, INSA-Lyon, CITI Lab, Inria Privatics, Mathy Vanhoef, KU Leuven

Welcoming Android 8.1 Oreo and Android Oreo (Go edition)

Posted by Dave Burke, VP of Engineering

At Google for India this Monday, we announced the final release of Android 8.1 Oreo. Android 8.1 Oreo is another exciting step toward bringing to life our vision of an AI-first mobile platform, for everyone, everywhere.

Android 8.1 introduces support for our new Android Oreo (Go edition) software experience for entry-level devices. Android Oreo (Go edition) brings the best of Android to the rapidly growing market for low-memory devices around the world, including your apps and games.

Android 8.1 also introduces the Neural Networks API, a hardware accelerated machine learning runtime to support ML capabilities in your apps. On supported devices, the Neural Networks API enables fast and efficient inference for a range of key use cases, starting with vision-based object classification.

You can get started with Android 8.1 Oreo (API level 27) today. We're pushing sources to Android Open Source Project now, and rolling out the update to supported Pixel and Nexus devices over the next week. We're also working with our device maker partners to bring Android 8.1 to more devices, including Android Oreo (Go edition) devices, in the months ahead.

Android Oreo (Go edition)

As announced at Google I/O 2017, the "Android Go" project is our initiative to optimize the Android experience for billions of people coming online around the world. Starting with Android 8.1, we're making Android a great platform for entry-level devices in the Android Oreo (Go edition) configuration:

  • Memory optimizations -- Improved memory usage across the platform to ensure that apps can run efficiently on devices with 1GB or less RAM.
  • Flexible targeting options -- New hardware feature constants to let you target the distribution of your apps to normal or low-RAM devices through Google Play.
  • Optimized Google apps: Rebuilt and optimized versions of Google apps, using less memory, storage space, and mobile data.
  • Google Play: While all apps will be available on Android Oreo (Go edition) devices, Google Play will give visibility to apps specifically optimized by developers to provide a great experience for billions of people with the building for billions guidelines.

We've updated the building for billions guidelines with additional guidance on how to optimize your app for Android Oreo (Go edition) devices. For most developers, optimizing your existing APK or using Google Play's Multiple APK feature to target a version of your APK to low-RAM devices is the best way to prepare for Android Oreo (Go edition) devices. Remember that making your app lighter and more efficient benefits your whole audience, regardless of device.

Neural Networks API

The Neural Networks API provides accelerated computation and inference for on-device machine learning frameworks like TensorFlow Lite -- Google's cross-platform ML library for mobile -- as well as Caffe2 and others. TensorFlow Lite is now available to developers, so visit the TensorFlow Lite open source repo for downloads and docs. TensorFlow Lite works with the Neural Networks API to run models like MobileNets, Inception v3, and Smart Reply efficiently on your mobile device.

Autofill enhancements and more

Android 8.1 includes select new features and developer APIs (API level 27), along with the latest optimizations, bug fixes, and security patches. Extend your app with Autofill enhancements, a SharedMemory API, and more. You can also add established Android Oreo features as well, see the Android Oreo site for details.

Test your apps on Android 8.1

If haven't already, take a few moments today to test your apps and make sure they offer the experience you want for users upgrading to Android 8.1 Oreo.

Just install your current app from Google Play onto a device or emulator running Android Oreo and test the user flows. The app should run and look great, and handle the Android Oreo behavior changes properly. In particular, pay attention to background location limits, notification channels, and changes in networking, security, and identifiers.

Speed your development with Android Studio

To build with Android 8.1, we recommend updating to Android Studio 3.0, which is now available from the stable channel. On top of the new app performance profiling tools, support for the Kotlin programming language, and Gradle build optimizations, Android Studio 3.0 makes it easier to develop for Android Oreo features like Instant Apps, XML Fonts, downloadable fonts, and adaptive icons.

With the final platform we're updating the SDK and build tools in Android Studio, as well as the API Level 27 emulator system images. We recommend updating to the Android Support Library 27.0.2, which is available from Google's Maven repository. See the version notes for details on what's new.

As always, we're providing downloadable factory and OTA images on the Nexus Images page to help you do final testing on your Pixel and Nexus devices.

Publish your updates to Google Play

When you're ready, you can publish your APK updates targeting API level 27 in your alpha, beta, or production channels. Make sure that your updated app runs well on Android Oreo as well as older versions. We recommend using beta testing to get early feedback from a small group of users and a pre-launch report to help you identify any issues, then do a staged rollout. Head over to the Android Developers site to find more info on launch best practices. We're looking forward to seeing your app updates!

What's next for Android Oreo?

We'll soon be closing the Developer Preview issue tracker, but please keep the feedback coming! If you still see an issue that you filed in the preview tracker, just file a new issue against Android 8.1 in the AOSP issue tracker. You can also continue to give us feedback or ask questions in the developer community.

Tuning your apps and games for long screen devices

Posted by Fred Chung, Developer Advocate

In recent months, there's a growing trend for handset makers to ship new devices with long screen aspect ratio (stretching beyond 16:9), many of which also sport rounded corners. This attests to the Android ecosystem's breadth and choice. Pixel 2 XL and Huawei Mate 10 Pro are just two of many examples. These screen characteristics could bring a very immersive experience to users and they take notice of apps and games that don't take advantage of the long aspect ratio screen on these new devices. Therefore it is important for developers to optimize for these screen designs. Let's have a look at related support provided by the Android OS.

Optimize for long aspect ratio screens

Most apps using standard UI widgets will likely work out-of-the-box on these devices. Android documentation details techniques for flexibly working on multiple screen sizes. However, some games and apps with custom UIs may run into issues due to incorrect assumptions on certain aspect ratios. We're sharing a few typical issues faced by developers, so you can pay attention to those relevant to you:

  • Certain sides of the screen are cropped. This makes any graphic or UI elements in the affected regions look incomplete.
  • Touch targets are offset from UI elements (e.g. buttons). Users may be confused on UI elements that are seemingly interactive.
  • For full screen mode on rounded corners devices, any UI elements very close to the corners may be outside of the curved corner viewable area. Imagine if a commerce app's "Purchase" button was partially obstructed? We recommend referencing Material Design guidelines by leaving 16dp side margins in layouts.

If responsive UI is really not suitable for your situation, as a last resort declare an explicit maximum supported aspect ratio as follows. On devices with a wider aspect ratio, the app will be shown in a compatibility mode padded with letterbox. Keep in mind that certain device models provide an override for users to force the app into full-screen compatibility mode, so be sure to test under these scenarios too!

Targets API level 26 or higher: Use android:maxAspectRatio attributes.

Targets API level 25 or lower: Use android.max_aspect meta-data. Note that maximum aspect ratio values will be respected only if your activities don't support resizableActivity. See documentation for detail.

System letterboxes an app when the declared maximum aspect ratio is smaller than the device's screen.

Consider using side-by-side activities

Long aspect ratio devices enable even more multi-window use cases that could increase user productivity. Beginning in Android 7.0, the platform offers a standard way for developers to implement multi-window on supported devices as well as perform data drag and drop between activities. Refer to documentation for details.

Testing is crucial. If you don't have access to one of these long screen devices, be sure to test on the emulator with adequate screen size and resolution hardware properties, which are explained in the emulator documentation.

We know you want to delight your users with long screen devices. With a few steps, you can ensure your apps and games taking full advantage of these devices!

10 things you might be doing wrong when using the SafetyNet Attestation API

Posted by Oscar Rodriguez, Developer Advocate

The SafetyNet Attestation API helps you assess the security and compatibility of the Android environments in which your apps run. Since it was introduced in March 2015, many developers have successfully integrated it into their Android apps to make more informed decisions based on the integrity and compatibility of the devices running their apps.

Throughout the years, the SafetyNet Attestation API has evolved, and its adoption has steadily increased. However, as with any security/anti-abuse related API, there are many common pitfalls that may lead developers into developing unstable systems, or worse, into a false sense of security.

In this post, we provide a list of the most common mistakes we have seen developers make when integrating the SafetyNet Attestation API.

1. Not getting an API key

Just like many other Google APIs, the SafetyNet Attestation API requires an API key in order to run. Furthermore, the SafetyNet Attestation API has a per-key usage quota. Although you can get this quota increased, you need to provide your API key to do so.

Getting an API key is easy and free of charge. There is no reason not to get an API key, so if you haven't already, get an API key now.

2. Not using the latest version of the API

The SafetyNet Attestation API has evolved throughout its history, and with it, there have been some interface changes. Most recently, with the release of Google Play services 11.0.0, we revamped the entire SafetyNet API to offer an interface that is easier and more streamlined to use: the new API uses SafetyNetClient instead of SafetyNetApi, which is now deprecated, so make sure you update your implementation to use the latest version of the API.

Most devices should have the latest version of Google Play services installed, but if a device doesn't have Google Play services installed, or doesn't have it up to date, using the SafetyNet Attestation API may lead to the app becoming unresponsive or crashing. You can prevent this by checking the installed version of Google Play services before using the API.

3. Using nonces incorrectly

The SafetyNet Attestation API lets you set a nonce to uniquely and globally identify each call to the API. Use this feature to prevent a malicious user from reusing a successful attestation result in place of an unsuccessful result (also known as a Replay Attack).

One good way to create a nonce is to create a large (16 bytes or longer) random number on your server using a cryptographically-secure random function. The SafetyNet attestation response includes the nonce you set, so make sure you verify that the returned nonce matches the one you included in the request you made.

4. Not checking the results on your server

SafetyNet can provide useful signals about the state of the device in which your app is running. However, if the logic that acts on these signals is only implemented and enforced directly on the device, an attacker could be able to modify your app and bypass any checks you perform.

To prevent this situation, you should run any logic that verifies the attestation result and enforces any actions based on them on a server that you control and trust.

5. Using the test attestation verification service for production

In order to simplify development and testing of the SafetyNet Attestation API, Google offers an online verification service that checks the digital signature of a SafetyNet Attestation result using a simple HTTPS request.

As useful as this service may seem, it is designed for test purposes only, and it has very strict usage quotas that will not be increased upon request. Instead, you should implement the digital signature verification logic on your server in a way that it doesn't depend on Google's servers. Most JWT libraries offer signature verification functionality, and we have code samples that show how to perform this verification in Java and C#. We plan to provide samples for more languages in the future.

6. Not checking the nonce, timestamp, APK name, and hashes

The SafetyNet Attestation API is most widely known for its integrity and compatibility checks, whose results are returned in ctsProfileMatch and basicIntegrity. Although these two values are indeed very useful, you should check the other values in the response, as they contain important information as well.

Use nonce to match a response to its request, as explained above, and use timestampMs to check how much time has passed since you made the request and you got the response. A delayed response that arrives several hours or days after the request may suggest suspicious activity.

Use apkPackageName to check the name of the APK that made the attestation request, and match apkDigestSha256 and apkCertificateDigestSha256 to those from your app's signed APK in Google Play, to get a signal about the integrity of the installed app.

Remember that the trustworthiness of the response as a whole is tied to the results of ctsProfileMatch and basicIntegrity. It is not unthinkable for a compromised device that fails basicIntegrity to have forged the rest of the values in the response.

7. Not understanding the differences between ctsProfileMatch and basicIntegrity

The SafetyNet Attestation API initially provided a single value called basicIntegrity to help developers determine the integrity of a device. As the API evolved, we introduced a new, stricter check whose results appear in a value called ctsProfileMatch, which allows developers to more finely evaluate the devices on which their app is running.

In broad terms, basicIntegrity gives you a signal about the general integrity of the device and its API. Rooted devices fail basicIntegrity, as do emulators, virtual devices, and devices with signs of tampering, such as API hooks.

On the other hand, ctsProfileMatch gives you a much stricter signal about the compatibility of the device. Only unmodified devices that have been certified by Google can pass ctsProfileMatch. Devices that will fail ctsProfileMatch include the following:

  • Devices that fail basicIntegrity
  • Devices with an unlocked bootloader
  • Devices with a custom system image (custom ROM)
  • Devices for which the manufactured didn't apply for, or pass, Google certification
  • Devices with a system image built directly from the Android Open Source Program source files
  • Devices with a system image distributed as part of a beta or developer preview program (including the Android Beta Program)

8. Not having a strategy for timing attestation checks

The SafetyNet Attestation API gives you a snapshot of the state of a device at the moment when the attestation request was made. A successful attestation doesn't necessarily mean that the device would have passed attestation in the past, or that it will in the future.

Because an attestation is just a spot check, you should plan a sensible strategy for choosing when to make attestation requests. You may choose to require successful attestations before users make in-app purchases, after a certain number of days have passed since the last successful attestation, each time your app is launched, after every reboot, or any other strategy that makes sense for your app.

Keep in mind that an attestation request is computationally expensive, consumes battery and bandwidth, and uses your quota. We recommend you plan a strategy to use the least amount of attestations required to satisfy your use case.

9. Using the SafetyNet Attestation API results as the only signal to attack abuse

It may be tempting to think that the SafetyNet Attestation API provides all the necessary signals for protecting an app against abusers, and use it as the only signal for building an anti-abuse system.

The SafetyNet Attestation API can only give signals about the state of a device, not the intent of a user, which is what an anti-abuse system should be designed to detect. Therefore, you might want to consider including other signals, such as access logs and behavioral patterns, to more accurately detect abusive users, and consider not blocking users solely on a failed attestation. Furthermore, there are many other conditions that cause an attestation to fail, such as network connection problems, quota issues, and other transient problems.

In other words, not all users who fail attestation are necessarily abusers, and not all abusers will necessarily fail attestation. By blocking users solely on their attestation results, you might be missing abusive users that don't fail attestations. Furthermore, you might also be blocking legitimate, loyal customers who fail attestations for reasons other than abuse.

10. Not monitoring and managing your usage quota

As mentioned before, the SafetyNet Attestation API is rate limited, and there is a default quota of 10,000 requests per day for each API key. Although this quota might be enough for most development, testing, and initial app launches, your app might reach the default limit as it increases in popularity.

To prevent inadvertently reaching your quota and getting attestation errors, you should build a system that monitors your usage of the API and warns you well before you reach your quota so you can get it increased. You should also be prepared to handle attestation failures because of an exceeded quota and avoid blocking all your users in this situation.

If you are close to reaching your quota, or expect a short-term spike that may lead you to exceed your quota, you can submit this form to request short or long-term increases to the quota for your API key. This process, as well as the additional quota, is free of charge.

Announcing Architecture Components 1.0 Stable

Posted by Lukas Bergstrom, Product Manager, Android Developer Frameworks Team

Android runs on billions of devices, from high-end phones to airplane seatbacks. The Android OS manages resources aggressively to perform well on this huge range of devices, and sometimes that can make building robust apps complicated. To make it easier, we launched a preview of Architecture Components at Google I/O to provide guidance on app architecture, with libraries for common tasks like lifecycle management and data persistence. Together, these foundational components make it possible to write modular apps with less boilerplate code, so developers can focus on innovating instead of reinventing the wheel - and we hope to keep building on this foundation in the future.

Today we're happy to announce that the Room and Lifecycle Architecture Components libraries have reached 1.0 stable. These APIs are ready for production apps and libraries, and are our recommendation for developers looking for help with app architecture and local storage (although they're only recommended, not required.) Lifecycles are now also integrated with the Support Library, so you can use them with standard classes like AppCompatActivity.

Although we're declaring them stable today, the beta components are already used in apps that together, have billions of installs. Top developers, like Zappos, have been able to spend more time on what's important thanks to Architecture Components:

Prior to the release of Android Architecture Components we had our own ViewModel implementation. We used Loaders and Dependency Injection to persist our ViewModel through config changes. We recently switched to the Architecture Components ViewModel implementation and all that boilerplate went away. We found that we were able to spend more time on design, business logic and testing, and less on writing boilerplate or worrying about Android lifecycle issues.

We've also started to use LiveData which hooks directly into the Activity lifecycle. We use it to retrieve and display network data and no longer have to concern ourselves with ​network call subscription management. - David Henry, Android Software Engineer, Zappos

Architecture Components provide a simple, flexible and practical approach that frees developers from some common problems so they can focus on building great experiences. This is based on core building blocks tied together by guidance on app architecture.

Lifecycles

Every Android developer has to deal with the operating system starting, stopping and destroying their Activities. That means managing the state of components - such as observables used to update UI - as you move through the lifecycle. Lifecycles enables the creation of lifecycle-aware components that manage their own lifecycles, reducing the possibility of leaks or crashes. The Lifecycle library is the foundation for other Architecture Components like LiveData.

LiveData

LiveData is a lifecycle-aware observable that holds data and provides updates. Your UI code subscribes to changes and provides LiveData a reference to its Lifecycle. Because LiveData is lifecycle-aware, it provides updates when its Lifecycle is started or resumed, but stops providing updates when the LifecycleOwner is destroyed. LiveData is a simple way to build reactive UIs that are safer and more performant.

ViewModel

ViewModel separates ownership of view data and logic from lifecycle-bound entities like Activities and Fragments. A ViewModel is retained until its associated Activity or Fragment is disposed of forever - that means view data survives events like a Fragment being recreated due to rotation. ViewModels not only eliminate common lifecycle issues, they help build UIs that are more modular and easier to test.

Room

Nearly all apps need to store data locally. While Android has bundled SQLite with the platform since version 1, using it directly can be painful. Room is a simple object-mapping layer that provides the full power of SQlite with less boilerplate. Features like compile-time query verification and built-in migration make it easier to build a robust persistence layer, while integration with LiveData lets Room provide database-backed, lifecycle-aware observables. Room blends of simplicity, power and robustness for managing local storage, and we hope you give it a try.

Guide to App Architecture and more

Last but not least, we created a Guide to App Architecture that provides core principles applicable to all developers, and specific guidance on using Architecture Components together. Because we've heard from you that clear and consistent guidance is important, today we're updating developer documentation to point to Architecture Components where appropriate. We also have a rich set of videos, codelabs and sample apps available at the Architecture Components site, with more to come.

Watch this space

Although the first set of Architecture Components is now stable, we know there's more work to do. Over the last few months, we've listened to your feedback and made improvements. We also recently launched a new Architecture Component, PagedList, to alpha, in response to your feedback that handling large datasets with RecyclerView is too difficult. This is just the beginning - we have more major components under development that we're looking to announce in the upcoming months.

Our hope with Architecture Components is to free developers to focus on providing unique new experiences for mobile devices. We're glad we can finally announce them as stable for production use. We'd like to thank the community, which has given such great feedback along the way, and we look forward to continuing the discussion in the comments of this post. Finally, for those of you who've been waiting for this stable launch, get started today.