Android Applications and Games

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Anbox apps short.png
Android OS Icon

Introduction[edit]

Ambox warning pn.svg.png Anbox disables the majority of the Android security model [1] and it uses a very outdated Android version with known vulnerabilities. [2]

Anbox is a third party project that allows Android applications and mobile games to run inside Whonix ™. According to the Anbox website: [3]

Anbox puts the Android operating system into a container, abstracts hardware access and integrates core system services into a GNU/Linux system. Every Android application will be integrated with your operating system like any other native application. To achieve our goal we use standard Linux technologies like containers (LXC) to separate the Android operating system from the host. Any Android version is suitable for this approach and we try to keep up with the latest available version from the Android Open Source Project.

The project is open source and theoretically any application can be run. Anbox does not have direct access to a user's hardware or data. It should be noted that while it is possible to install the Google Play Store, Google will not allow anyone to ship applications if the device is not certified and the vendor has not signed an agreement. [4]

Community Support Only!:
Info

Community Support Only means Whonix ™ developers are unlikely to provide free support for wiki chapters or pages with this tag. See Community Support for further information, including implications and possible alternatives.

Security Notes[edit]

  • Do not use physical devices (mobile phones or tablets) for any kind of anonymous activities because any physical device has a unique IMEI number which can be easily fetched by Android applications. Always use virtual devices such as Anbox or Android x86 for these kind of activities.
  • Always prefer using free and open source (FOSS) Android applications because they usually don't use any kind of surveillance. Using applications from F-Droid repositories is recommended.
  • Do not install Android Package Kits (APKs) directly from untrusted sources.
  • Always check permissions before starting an application. Note the Android settings menu only allows the user to manage dangerous permissions (such as Camera, Storage, Location, Phone etc.) but not AppOps (application operations) permissions. ADB shell or extended GUI application/permission manager (root required) is needed in order to display and manage not only dangerous but AppOps permissions.
  • Do not store any private information inside Anbox or Android x86 filesystems.
  • As the Android system cannot prevent applications from accessing the Internet, additional firewall management is required. Android uses Linux iptables firewall manager so a GUI application like AFWall+ can be used to control what applications are allowed to access the Internet (root needed).
  • If a proprietary, non-free Android application installation is required, prefer installation from Google Play Store using an anonymous account. An Aurora Store application can be useful for this purpose. Do not use your real Google Account and do not download and install APKs from third-party websites because it can be dangerous. [5]

General Issues[edit]

There are several issues with running popular Android applications using Anbox or Android x86 Workstation on top of a non-physical, certified Android device.

Unsupported CPU Architecture[edit]

Most popular Android applications (especially from Google Play Store) were written for ARMv7 and rarely for ARMv8 architectures. Therefore, some applications do not have support for x86 or x86_64 architectures. Android x86 users can use the libhoudini library in order to try to emulate ARMv7 architecture but many Android applications written for ARM still don't work.

Device Fingerprint[edit]

Many non-free, popular Android applications check the device fingerprint for hardware identification purposes. Both Anbox and Android x86 have emulator fingerprints so applications can easily detect that an emulator is in use. It is generally possible to spoof the device fingerprint, but it is necessary to rebuild the Android image for Anbox. Android x86 can utilize the Magisk module called MagiskHide Props Config in order to spoof the device fingerprint.

Network Interface Detection[edit]

Most popular Android applications detect network adapters and will not work properly if no Wi-Fi or mobile connection is established. Anbox uses a bridge network interface by default so some applications will not see the Internet connection. However, Android x86 starting from Nougat has a built-in virtual Wi-Fi interface so applications think that a real Wi-Fi connection is established.

Google Play Services Mechanisms[edit]

At present, the biggest problem with running popular Android applications on top of a non-physical Android device is passing SafetyNet by Google. Android consists of two parts:

  • The Android system itself (Android Open Source Project). This is a base system.
  • A proprietary subsystem called Google Play Services. This helps applications from Google Play Store to interact with Google servers. This is an optional subsystem but all Android devices which are certified by Google have this arrangement.

If only free software (FOSS) applications will be run, then Google Play Services is unneeded since all applications from F-Droid are built without a dependency upon Google Play Services. If some types of proprietary applications are needed, this can be problematic because some will use the Google Play Services mechanism.

Generally, Google Play Services consists of two important parts:

  • GCM (Google Cloud Messages)
  • SafetyNet

GCM is a proprietary mechanism for delivering Push Notifications from Google servers. GCM is used by ~70-80% of proprietary applications from Google Play Store which rely upon the mechanism. It is not difficult to enable GCM support for both Android x86 and Anbox. The Android x86 image comes with built-in, non-free Google Play Services so GCM is enabled by default. With Anbox, it is possible to install either proprietary Google Play Services (OpenGAPPS) or an open-source implementation of Google Play Services called Micro-G.

SafetyNet is a mechanism which verifies the integrity of the device. If a device is not certified by Google Corporation then most of the proprietary Android applications from Google Play Store will not run because many use SafetyNet to check the device is authentic and has not been tampered with. Nowadays there is no way to pass SafetyNet on either Android x86 or Anbox because Google uses its own closed-source algorithm for non-real devices detection. SafetyNet is used by ~30-50% of Google Play Store applications, especially those relating to banking and social networks such as Tinder.

Anbox inside Whonix ™ vs. Android x86 Workstation[edit]

There are both distinct advantages and disadvantages of running Android applications in a native Whonix-Workstation ™ versus an Android x86 Workstation. [6]

Table: Anbox Advantages and Disadvantages [7]

Category Notes
Bootloader / Ramdisk Anbox does not have any type of bootloader and ramdisk. Consequently it is impossible to install Magisk or some kind of recovery tool which is probably necessary for some operations like hiding root from applications (for example Magisk Hide).
Emulation No emulation is required, therefore Android applications can be run in a native Whonix-Workstation ™ environment.
Flexibility
  • It is easy to use Android Debug Bridge (adb) to install/remove applications and to push/pull files from/to the Anbox environment.
  • Root access - Anbox does not provide a superuser binary and manager. A manual installation of a superuser binary and application is required, which necessitates a rebuild of the Android image.
Networking Anbox does not provide a virtual Wi-Fi (wlan0) interface so some applications will not see the Internet connection.
Speed Android applications run faster in this configuration.

Table: Android x86 Workstation Advantages and Disadvantages

Category Notes
Bootloader / Ramdisk It is possible to use Magisk to achieve root permissions and hide root from applications on Android x86. [8]
Flexibility
  • It is possible to use adb if Android x86 uses the same internal network as the Gateway and Workstation. [9]
  • Root access - Android x86 has a pre-installed superuser binary and manager so root access works out of the box. Applications with root access will work without any additional setup.
Networking Android x86 provides a virtual Wi-Fi interface (wlan0) so applications think that a real Wi-Fi connection is established (Anbox uses a bridge network interface).
Operating System The full Android stack implemented as Android x86 is a full operating system which requires hardware virtualization (unlike Anbox).
Security This configuration is less secure than utilizing a Whonix-Workstation ™. [10]
Software Any version of Android from 4.x to 9.x can be installed (Anbox provides only Nougat).
Speed This configuration is slower as Android x86 does not provide any type of Guest Additions meaning no graphic card drivers are supported.

Anbox Installation[edit]

Base Software[edit]

Perform all installation steps inside Whonix-Workstation ™. No Whonix-Gateway ™ modifications are required.

Install package(s) linux-image-amd64 linux-headers-amd64 adb fastboot anbox.

A. Update the package lists and upgrade the system.

sudo apt update && sudo apt full-upgrade

B. Install the linux-image-amd64 linux-headers-amd64 adb fastboot anbox package(s).

Using apt command line parameter --no-install-recommends is in most cases optional.

sudo apt install --no-install-recommends linux-image-amd64 linux-headers-amd64 adb fastboot anbox

C. Done.

The procedure of installing package(s) linux-image-amd64 linux-headers-amd64 adb fastboot anbox is complete.

Android Image[edit]

1. Download Anbox Android image.

If this is required inside a Qubes Template then parameter --proxy http://127.0.0.1:8082 must be added to scurl as shown below.

Supported only --tlsv1.2 at time of writing. [11]

  • Non-Qubes-Whonix ™ (or Qubes StandaloneVM):
    scurl --tlsv1.2 --remote-name https://build.anbox.io/android-images/2018/07/19/android_amd64.img
  • Qubes-Whonix ™ Template:
    scurl --proxy http://127.0.0.1:8082 --tlsv1.2 --remote-name https://build.anbox.io/android-images/2018/07/19/android_amd64.img

2. Download Anbox Android image sha256sum file.

  • Non-Qubes-Whonix ™ (or Qubes StandaloneVM):
    curl --tlsv1.2 --remote-name https://build.anbox.io/android-images/2018/07/19/android_amd64.img.sha256sum
  • Qubes-Whonix ™ Template:
    curl --proxy http://127.0.0.1:8082 --tlsv1.2 --remote-name https://build.anbox.io/android-images/2018/07/19/android_amd64.img.sha256sum

3. Verify the image.

sha256sum --check android_amd64.img.sha256sum

Should show: 

android_amd64.img: OK

4. Move (rename) android_amd64.img to /var/lib/anbox/android.img. [12]

sudo mv android_amd64.img /var/lib/anbox/android.img

[13]

Anbox Configuration[edit]

Derivative Specific[edit]

Disabling Whonix-Workstation ™ Firewall is unfortunately required. Otherwise there would be no network access. [14]

Ambox warning pn.svg.png This reduces security! Especially when using multiple Whonix-Workstation ™ behind the same Whonix-Gateway ™.

1. Inside Whonix-Workstation ™.

(Qubes-Whonix ™: inside StandaloneVM (better!) or Template).

sudo systemctl mask whonix-firewall

2. Disable systemcheck in Whonix-Workstation ™ Firewall.

Open file /etc/systemcheck.d/50_user.conf in an editor with administrative (root) write permissions.

This box uses sudoedit for better security. This is an example and other tools can also achieve the same goal. If this example does not work for you or if you are not using Whonix ™, please refer to this link.

sudoedit /etc/systemcheck.d/50_user.conf

Paste.

systemcheck_skip_functions+=" check_whonix_firewall_systemd_status "

Save.

3. Reboot.

This is required to unload Whonix-Workstation ™ firewall rules and to have Anbox load its firewall rules.

sudo reboot

Qubes[edit]

Info Qubes users only.

A StandaloneVM is most suitable, otherwise changes will be non-persistent (lost after VM restart). Instructions on how to make Anbox persistent using a TemplateBased AppVM do not exist yet; see footnote for experimental instructions. [15]

Qubes-Whonix ™ requires the use of a Qubes VM kernel. [16] Users can follow the instructions from the Qubes website Installing kernel in Debian VM which are equally functional in Qubes-Whonix ™.

It has been reported that it is necessary to enable Anbox software rendering, but it is unclear how to accomplish that at present. The command from the previous link is likely non-functional because this guide does not use snap. Snap is not utilized because that would break the Always Verify Signatures recommendation (snap does not verify software signatures). [17]

Start Anbox[edit]

From Start Menu[edit]

Start menu → Accessories → Anbox

From Command Line[edit]

[18]

anbox launch --package=org.anbox.appmgr --component=org.anbox.appmgr.AppViewActivity

Usage[edit]

F-Droid Installation[edit]

It is suggested to install F-Droid. The instructions below document how to download and verify F-Droid inside Whonix-Workstation ™. [19]

1. Download the F-Droid signing key.

notice Digital software signatures can increase security but this requires knowledge. Learn more about digital software signature verification.

Securely download the signing key.

scurl-download "https://keyserver.ubuntu.com/pks/lookup?op=get&search=0x37d2c98789d8311948394e3e41e7044e1dba2e89"

Display the key's fingerprint.

gpg --keyid-format long --import --import-options show-only --with-fingerprint 'lookup?op=get&search=0x37d2c98789d8311948394e3e41e7044e1dba2e89'

Verify the fingerprint. It should show.

gpg: key 41E7044E1DBA2E89: 60 signatures not checked due to missing keys

pub rsa4096/41E7044E1DBA2E89 2014-04-25 [C] Key fingerprint = 37D2 C987 89D8 3119 4839 4E3E 41E7 044E 1DBA 2E89 uid F-Droid <admin@f-droid.org> sub rsa3072/5DCCB667F9BF9046 2014-04-25 [E] [expires: 2026-04-25]

sub rsa3072/7A029E54DD5DCE7A 2014-04-25 [S] [expires: 2026-04-25]

The most important check is confirming the key fingerprint exactly matches the output below. [20]

warning Warning:

Do not continue if the fingerprint does not match! This risks using infected or erroneous files! The whole point of verification is to confirm file integrity.

Add the signing key.

gpg --import 'lookup?op=get&search=0x37d2c98789d8311948394e3e41e7044e1dba2e89'

2. Download F-Droid.

scurl-download https://f-droid.org/FDroid.apk

3. Download F-Droid signature.

scurl-download https://f-droid.org/FDroid.apk.asc

4. Verify F-Droid.

gpg --verify FDroid.apk.asc

Should show. 

gpg: assuming signed data in 'FDroid.apk'
gpg: Signature made Fri 16 Apr 2021 09:26:14 AM UTC
gpg:                using RSA key 802A9799016112346E1FEFF47A029E54DD5DCE7A
gpg: Good signature from "F-Droid <admin@f-droid.org>" [unknown]
gpg: WARNING: This key is not certified with a trusted signature!
gpg:          There is no indication that the signature belongs to the owner.
Primary key fingerprint: 37D2 C987 89D8 3119 4839  4E3E 41E7 044E 1DBA 2E89
     Subkey fingerprint: 802A 9799 0161 1234 6E1F  EFF4 7A02 9E54 DD5D CE7A

5. Install F-Droid inside Anbox using adb.

adb install FDroid.apk

Images[edit]

Figure: F-Droid Images

Fdroid.png

Fdroid2.png

Fdroid3.png

File Sharing[edit]

In a terminal, run. [21]

lxsudo thunar

Browse to:

/var/lib/anbox/rootfs/data/media/0/

Files dropped to this download directory are readily visible to applications within Anbox.

Forum Discussion[edit]

Alternatives[edit]

Footnotes[edit]

  1. ↑ For example it disables SELinux which is a core part of the security model; see https://github.com/anbox/platform_system_core/commit/71907fc5e7833866be6ae3c120c602974edf8322
  2. ↑ See the dates on the Github repositories. https://github.com/anbox
  3. ↑ https://anbox.io/#about
  4. ↑ https://anbox.io/#faq
  5. ↑ Note that most non-free applications from Google Play Store will not work properly without Google Play Services installed. Some will never work at all because an Android virtual device cannot pass Google's SafetyNet mechanism.
  6. ↑ https://forums.whonix.org/t/integrate-anbox-into-whonix-workstation/9642
  7. ↑ The networking and software disadvantages below are very critical.
  8. ↑ Some individuals have already achieved this on Android x86.
  9. ↑ Also, it may be possible to run ssh-server on Whonix-Workstation ™ and connect the Android x86 through Termux or similar.
  10. ↑ Although it may have more flexibility, as static IP connections on the Android x86 Workstation have been accomplished.
  11. ↑ https://forums.whonix.org/t/anbox-install-trouble-handshake-failure/13308
  12. ↑ anbox-container-manager.service expects this file name.
  13. ↑ The following steps are probably not required because it should work out of the box after rebooting.

    Start kernel module.

    sudo modprobe ashmem_linux

    Start kernel module.

    sudo modprobe binder_linux

    Start anbox systemd service.

    sudo systemctl start anbox-container-manager.service

    Check if anbox systemd service is functional.

    sudo systemctl status anbox-container-manager.service

    Should show something similar to the following. 

    ● anbox-container-manager.service - Anbox Container Manager
   Loaded: loaded (/lib/systemd/system/anbox-container-manager.service; enabled; vendor preset: enabled)
   Active: active (running) since Mon 2018-12-31 06:23:49 EST; 874ms ago
     Docs: man:anbox(1)
  Process: 1996 ExecStartPre=/usr/share/anbox/anbox-bridge.sh start (code=exited, status=0/SUCCESS)
  Process: 1991 ExecStartPre=/sbin/modprobe binder_linux (code=exited, status=0/SUCCESS)
  Process: 1986 ExecStartPre=/sbin/modprobe ashmem_linux (code=exited, status=0/SUCCESS)
 Main PID: 2074 (anbox)
    Tasks: 9 (limit: 4915)
   Memory: 5.1M
      CPU: 51ms
   CGroup: /system.slice/anbox-container-manager.service
           └─2074 /usr/bin/anbox container-manager --daemon --privileged --data-path=/var/lib/anbox

Dec 31 06:23:48 debian systemd[1]: Starting Anbox Container Manager...
Dec 31 06:23:49 debian systemd[1]: Started Anbox Container Manager.
  14. ↑ This is because Anbox comes with its own bridged network. Whitelisting that interface in Whonix-Workstation ™ firewall is undocumented and might require source code modifications. Patches are Welcome.
  15. ↑ These steps do not work yet. 
    [ 2019-10-14 11:00:41] [launch.cpp:214@operator()] Session manager failed to become ready

    1. Increase VM private storage.

    • Power off the VM.
    • Add at least 2 GB more private storage to the VM. This can be done using Qubes VM Manager (QVMM).
    • Reboot the VM.

    2. Add /var/lib/anbox to Qubes bind-dirs.

    Create folder /rw/config/qubes-bind-dirs.d.

    sudo mkdir -p /rw/config/qubes-bind-dirs.d

    Create a new configuration file /rw/config/qubes-bind-dirs.d/50_user.conf.

    sudoedit /rw/config/qubes-bind-dirs.d/50_user.conf

    Paste.

    binds+=( '/var/lib/anbox' )

    Save.

    3. Reboot the VM.

    This results in storing /var/lib/anbox in the private rather than the root image. This means changes will persist rather than be lost after a VM restart.

    4. Fix file permissions.

    Ambox warning pn.svg.png Warning: the following steps might cause security issues.

    sudo systemctl stop anbox-container-manager.service

    sudo chown --recursive user:user /var/lib/anbox

    sudo systemctl start anbox-container-manager.service
  16. ↑ Using a VM kernel is currently challenging to use because Anbox is implemented using kernel modules, see: Simplify and promote using in-vm kernel.
  17. ↑ https://forums.whonix.org/t/snap-store-snaps-snapcraft-io-a-new-software-source/7631
  18. ↑ /usr/share/applications/anbox.desktop
  19. ↑ https://f-droid.org/docs/Release_Channels_and_Signing_Keys/
  20. ↑ Minor changes in the output such as new uids (email addresses) or newer expiration dates are inconsequential.
  21. ↑ https://forums.whonix.org/t/running-android-apps-inside-whonix-workstation-anbox-proof-of-concept/7441/13


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