CODEWITHSUNDEEP
android
StayCool
StayCool

Reputation: 449

How to get system app permission on Android 9.0

I want to grant my application with system permission "INJECT_EVENTS" on Android 9.0 device, but I can't.

<uses-permission android:name="android.permission.INJECT_EVENTS"
                     android:protectionLevel="signature"
                     tools:ignore="ProtectedPermissions" />

Also I've read https://source.android.com/devices/tech/config/perms-whitelist article and moved apk to /system/priv-app, and then tried to whitelist my apk with inject_events permission in next places:

First try:

Second try:

This is how my whitelist edits look like in both files:

    <privapp-permissions package="com.my.apk">
       <permission name="android.permission.INJECT_EVENTS"/>
    </privapp-permissions>
   </permissions>

*I tried to debug this by grep'ing logcat with "PackageManager", but nothing useful. Also adb shell dumpsys package myapk | grep permission shows that permission.INJECT_EVENTS is not granted.

important: apk is granted inject_events while running on android 8.1. No whitelisting was used.

After everything done It was expected that inject_events will be granted, but no.

Upvotes: 0

Views: 4237

Answers (1)

StayCool
StayCool

Reputation: 449

I solved it. The thing is I have SAMSUNG A205FN. And stock ROM, signed by Samsung. To convert my app to system app I need to sign it with ROM's sign. In common, it's Android release signature, that can be found in their repo. But SAMSUNG's signature is a secret one, so it's impossible.

Workaround: If you have SAMSUNG phone, just flash GSI ROM and use Android's signature.

P.S. To understand what signature should I use I took all system apps and priv-apps from phone and have read their signature. It revealed that all of them are signed by SAMSUNG and none are signed by Android. Maybe, for that exists an easier way.

First, find all priv-app apks and copy them to pc:

adb shell find /system/priv-app -name "*.apk" -exec cp {} /path/to/copy \;

and then print certificates and grep them by "Common Name" CN. Also you can look closed using CN=Android or else

ls | xargs -L 1 keytool -printcert -jarfile | grep CN=

P.S. If you have not SAMSUNG phone, to easily convert app to system app you can use systemizer app (Magisk->Modules->Systemizer and download)

Upvotes: 1

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