I'm developing a remote-control application for Android.
I want to be able to lock/unlock the screen.
To do this there are two ways:
Making the app a Device Administrator.
Using PowerManager.goToSleep(), which requires the DEVICE_POWER permission, which is a system permission.
So eclipse tells me "this permission is only granted to system apps".
I really need this and some other system permissions in my app, as it's a remote control app that must be able to control system features.
From the support page:
Uploading System Applications
Most developers will not need to upload system applications and may ignore this section. System applications may come pre-installed on certain devices and may or may not already be published in the Play store.
If you need to upload a system application and encounter an error message when doing so, please contact us. Please be sure to select the Publishing issues and distribution option.
If I'm understanding it right, It's possible to make a system application. how?
I'm developing a remote-control application for Android
Fortunately, this is not possible, except perhaps if you run as root, or you download the Android source code, modify it, and roll it into your own ROM mod.
If I'm understanding it right, It's possible to make a system application. how?
Build your own ROM mod. Sign the app with the same signing key as is used to sign your ROM mod. Put your app in your ROM mod. Install your ROM mod on your device.
This, of course, will limit your app's distribution to those devices running your ROM mod.
A lot of “system” permissions are really SIGNATURE_OR_SYSTEM permissions. For those, you need to do one of the following:
After building the APK, install it as a system app.
Sign the app with the same key as the Android distribution on your device.
For the first option, you would need to be root on your device. Regular APKs reside in /data/app, while system APKs need to be placed in a different folder (on Android 6 and 7 it’s /system/priv-app, earlier versions may differ). However, this is not very suitable for an app to be distributed to end users, especially if your target audience is not very tech-savvy.
For the second option, you need to build Android from source for your target device. If you sign the app with the same key as your Android build, then users running that build of Android can install it in the usual manner.
Related
I was looking for an answer whether Google allows to install externall C++ applications together with Android Apps on Google Play. I found some information on this site: Developer Policy Center - Malicious Behavior.
They say, that the following sentence is explicitly prohibited:
Apps that install other apps on a device without the user's prior consent.
Now my question is, what exactly does mean other apps? It is about other apps in Google play or any apps like my external C++ program that I want to execute in Android app? Does I have to inform users that some C++ app will be installed in the device?
first i you want to execute an c/c++ application in android , the only right and best way is to convert that app to a static or shared library using android NDK and after that you can use it by Java Native Interface (JNI).
second , "other apps" in the sentence that you mentioned in your question , some application can install some applications in system without user permission. for example in a rooted device we can simply install application without showing any windows or getting permission. in android old release because of some security issue in non-root device we was able to install an application without asking permission.
see this link for more information :
https://paulononaka.wordpress.com/2011/07/02/how-to-install-a-application-in-background-on-android/
Update
google wont allow developers to do that because android system cannot track this executive and it could be virus or dangerous tool that may harm android system
The device my Android app is running does not have Playstore on it. The plan is to pre-install the software when shipping the device. I am now looking for a strategy to upgrade the application.
I found this useful link to install an Android app from the apk file:
Android: install .apk programmatically
I am thinking I will use this logic to auto-upgrade my app. I am wondering if it is even possible. I am thinking the upgrade will first try to uninstall existing version but will fail as the executable is still running and the file may be locked. Is there a better way? Regards.
Peter, we've just implemented the same thing.
Users have the software pre-installed on their device and we host update APK's on the companies servers.
From the app they can then check for updates where we have a WCF service which extracts the APK file (essentially a .zip) and returns the manifest details. From there we have the version of the APK and can compare it against the local version.
If the user decides to upgrade they can download the APK and you can automatically launch it. At which point the user will be told the application is going to be updated. There are no file locks etc, the app will just close and restart using the new version.
Note: Downgrading is not "automatic". The user would have to first uninstall the app. For upgrades, however, it's a simple case of downloading and launching the APK version (the user will be told they need to allow installations from unknown sources if this is not checked).
You have a couple of options, depending upon your target system.
Use the link you posted. This will provide the user with a traditional install dialog, whereby the user can choose to install or not. You should avoid doing that automatically, as APKs can be large and you might irritate the user if they don't want updates.
You can install updates magically, but you will require the firmware signing key (or possibly root, but I haven't tested that). That will not ask for consent from the user. You will need to add additional code using reflection to access the installation methods of Android. If you go this way, you should build an opt-out/in mechanism.
If your app is open-source, F-Droid would solve the problem for you.
F-Droid is an installable catalogue of FOSS (Free and Open Source
Software) applications for the Android platform. The client makes it
easy to browse, install, and keep track of updates on your device.
Mainly, it updates your app when necessary. (Or just have a look at its source code for inspiration on how to do it).
Yes but as far as I remember only if you had Root privileges in order to have access to the INSTALL_PACKAGES permission.
I want to create an system application(while installing it will ask user permission to make it as system app) for UN-rooted application. As I am not familiar in android, please tell me how to create it.
Thanks in advance.
True system apps are baked into the ROM image, and signed with the same key the ROM was signed with, giving them extra access to the system.
You cannot add a new system app on the same level without updating the ROM image of the device, and even then you'll need the OEM key to sign your app and you will have to request them to include it in their ROM.
Having a rooted device allows standard apps to gain extra access without being system apps.
I have a question. How can I make an Android app installation to work similar as works installation from the official App Store for Android? (http://en.wikipedia.org/wiki/List_of_mobile_software_distribution_platforms) Do I need to have Root access? Or should it be a special version of Android where App Store will work as Google Play? Currently, I’m only able to install applications as “Unknown Sources”, where my application downloads the apk File and calls a system installation window where user confirms the installation. The problem here is that the file to be installed can be copied (even just a brief moment). It may be ok for free applications or the ones with server authentication (log/pas) but for paid apps it could be a problem.
Even if you install the app and delete the APK, it's still very easy to recover the APK of an installed application. The only way you can really protect your app is by using in-app licensing checks or locking the app to a certain device by using the device's id.
Further, on unrooted devices, you can not install apps outside of the Google Play store, unless you enable installation from unknown sources. To get around that restriction -- and to allow auto-updating or silent installation -- you will need to root and install a modified package manager.
Can somebody explain to me what are the benefits of Android System App over a "normal" app
(besides that fact that a system app cannot be uninstalled)?
Special permissions?
There is some confusion here.
First, if you are talking about "system app" as just being one with FLAG_SYSTEM set, all this means is that the app is located on the /system partition, which is the read-only partition that is basically the firmware of the device. (It can only be modified as part of an OTA firmware update.) These apps can't be removed simply because they are on a partition that can't be modified.
The only thing special about a system application beyond this is that there are a handful of signature permissions that can also be granted to any app on the system image. For example there is a permission to directly talk with the package manager to install an app (without going through the system UI) that such an app can have; this is useful for any app store / market pre-loaded on a device.
Being signed with the platform certificate is an orthogonal concept -- such an app can be either on the system image or installed as a third party app (though obviously in almost all cases these come pre-installed). Such apps have access to a whole suite of low-level permissions for interacting with the platform. Very few apps are signed with this certificate; it is only for core platform applications. Unless you are working with a hardware vendor on a device, you won't have access to this.
All of the platform's certificates (whether they be available to all apps, require an app be signed with the platform cert, or are available to apps installed on the system partition) are declared by the platforms manifest, just like any other app:
https://android.googlesource.com/platform/frameworks/base/+/master/core/res/AndroidManifest.xml
There are permissions that can only be obtained by systems apps. For example the permission brick can be requested by every app but it is only granted to apps that are signed as system apps. There are some other features that make more sense I think directly installing and removing apps would be a system only permission too.
From your explanation I guess you mean the the pre-installed applications (like the Browser or the Messages app). You can take a look in these apps at https://android.googlesource.com. (search for platform/packages/apps/...).
You will find that these application are no difference to your own custom developed Apps, except you can't remove them. They cannot be removed as they provide the basic functionality to operate your phone / device. So, same security constraints apply there.