Implement custom permission system for plugins

plugins/sdk/src/main/AndroidManifest.xml

@@ -0,0 +1,13 @@
+<manifest xmlns:android="http://schemas.android.com/apk/res/android">
+    <application>
+        <activity
+            android:name=".permissions.RequestPermissionActivity"
+            android:exported="true"
+            android:theme="@android:style/Theme.DeviceDefault.Dialog.NoActionBar.MinWidth">
+            <intent-filter>
+                <action android:name="de.mm20.launcher2.plugin.REQUEST_PERMISSION" />
+                <category android:name="android.intent.category.DEFAULT" />
+            </intent-filter>
+        </activity>
+    </application>
+</manifest>

plugins/sdk/src/main/java/de/mm20/launcher2/sdk/base/BasePluginProvider.kt

@@ -8,17 +8,22 @@ import android.os.Bundle
 import de.mm20.launcher2.plugin.PluginType
 import de.mm20.launcher2.plugin.contracts.PluginContract
 import de.mm20.launcher2.sdk.PluginState
+import de.mm20.launcher2.sdk.permissions.PluginPermissionManager
+import de.mm20.launcher2.sdk.permissions.permissionsDataStore
+import kotlinx.coroutines.flow.first
 import kotlinx.coroutines.runBlocking
 
 abstract class BasePluginProvider : ContentProvider() {
 
     override fun call(method: String, arg: String?, extras: Bundle?): Bundle? {
+        val context = context ?: return null
         return when (method) {
             PluginContract.Methods.GetType -> Bundle().apply {
                 putString("type", getPluginType().name)
             }
 
             PluginContract.Methods.GetState -> {
+                checkPermissionOrThrow(context)
                 val state = runBlocking {
                     getPluginState()
                 }
@@ -27,6 +32,7 @@ abstract class BasePluginProvider : ContentProvider() {
             }
 
             PluginContract.Methods.GetConfig -> {
+                checkPermissionOrThrow(context)
                 getPluginConfig()
             }
 
@@ -45,7 +51,12 @@ abstract class BasePluginProvider : ContentProvider() {
     }
 
     internal fun checkPermissionOrThrow(context: Context) {
-        if (context.checkCallingPermission(PluginContract.Permission) == PackageManager.PERMISSION_GRANTED) {
+        val callingPackage = callingPackage ?: throw IllegalArgumentException("No calling package")
+        val permissionManager = PluginPermissionManager(context)
+        val hasPermission = runBlocking {
+            permissionManager.hasPermission(callingPackage).first()
+        }
+        if (hasPermission) {
             return
         }
         throw SecurityException("Caller does not have permission to use plugins")

plugins/sdk/src/main/java/de/mm20/launcher2/sdk/permissions/DataStore.kt

@@ -0,0 +1,25 @@
+package de.mm20.launcher2.sdk.permissions
+
+import android.content.Context
+import androidx.datastore.core.Serializer
+import androidx.datastore.dataStore
+import java.io.InputStream
+import java.io.OutputStream
+
+internal val Context.permissionsDataStore by dataStore(
+    fileName = "plugin_permissions",
+    serializer = PermissionsSerializer,
+)
+
+internal object PermissionsSerializer : Serializer<Set<String>> {
+    override val defaultValue: Set<String>
+        get() = emptySet()
+
+    override suspend fun readFrom(input: InputStream): Set<String> {
+        return input.bufferedReader().readLines().toSet()
+    }
+
+    override suspend fun writeTo(t: Set<String>, output: OutputStream) {
+        output.bufferedWriter().write(t.joinToString("\n"))
+    }
+}

plugins/sdk/src/main/java/de/mm20/launcher2/sdk/permissions/PluginPermissionManager.kt

@@ -0,0 +1,32 @@
+package de.mm20.launcher2.sdk.permissions
+
+import android.content.Context
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.map
+import kotlinx.coroutines.runBlocking
+
+class PluginPermissionManager(
+    context: Context,
+) {
+    private val dataStore = context.applicationContext.permissionsDataStore
+
+    fun hasPermission(pluginPackage: String): Flow<Boolean> {
+        return dataStore.data.map { it.contains(pluginPackage) }
+    }
+
+    fun grantPermission(pluginPackage: String) {
+        runBlocking {
+            dataStore.updateData {
+                it + pluginPackage
+            }
+        }
+    }
+
+    fun revokePermission(pluginPackage: String) {
+        runBlocking {
+            dataStore.updateData {
+                it - pluginPackage
+            }
+        }
+    }
+}

plugins/sdk/src/main/java/de/mm20/launcher2/sdk/permissions/RequestPermissionActivity.kt

@@ -0,0 +1,64 @@
+package de.mm20.launcher2.sdk.permissions
+
+import android.app.Activity
+import android.content.pm.PackageManager
+import android.os.Bundle
+import android.text.Html
+import android.view.LayoutInflater
+import de.mm20.launcher2.sdk.R
+import de.mm20.launcher2.sdk.databinding.ActivityRequestPermissionBinding
+import kotlinx.coroutines.flow.first
+import kotlinx.coroutines.runBlocking
+
+class RequestPermissionActivity: Activity() {
+
+    private lateinit var binding: ActivityRequestPermissionBinding
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        val callingPackage = callingPackage ?: throw IllegalArgumentException("No calling package")
+
+        val callingPackageInfo = try {
+            packageManager.getApplicationInfo(callingPackage, 0)
+        } catch (e: PackageManager.NameNotFoundException) {
+            throw IllegalArgumentException("Invalid calling package")
+        }
+
+        val myPackageInfo = try {
+            packageManager.getApplicationInfo(packageName, 0)
+        } catch (e: PackageManager.NameNotFoundException) {
+            throw IllegalStateException("Invalid package")
+        }
+
+
+        val permissionManager = PluginPermissionManager(this)
+
+        val hasPermission = runBlocking {
+            permissionManager.hasPermission(callingPackage).first()
+        }
+
+        if (hasPermission) {
+            finish()
+            return
+        }
+
+        binding = ActivityRequestPermissionBinding.inflate(LayoutInflater.from(this))
+        val text = getString(
+            R.string.request_permission_message,
+            callingPackageInfo.loadLabel(packageManager),
+            myPackageInfo.loadLabel(packageManager)
+        )
+        binding.textView.text = Html.fromHtml(text, Html.FROM_HTML_MODE_LEGACY)
+        setContentView(binding.root)
+        binding.grantButton.setOnClickListener {
+            permissionManager.grantPermission(callingPackage)
+            setResult(RESULT_OK)
+            finish()
+        }
+        binding.denyButton.setOnClickListener {
+            permissionManager.revokePermission(callingPackage)
+            setResult(RESULT_CANCELED)
+            finish()
+        }
+    }
+}

plugins/sdk/src/main/res/layout/activity_request_permission.xml

@@ -0,0 +1,33 @@
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="match_parent"
+    android:layout_height="wrap_content"
+    android:orientation="vertical"
+    android:padding="24dp">
+
+    <TextView
+        android:id="@+id/textView"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        style="@android:style/TextAppearance.DeviceDefault"/>
+
+    <LinearLayout
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:layout_marginTop="24dp"
+        android:gravity="end">
+
+        <Button
+            android:id="@+id/deny_button"
+            style="@android:style/Widget.DeviceDefault.Button.Borderless"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:text="@string/request_permission_deny_button" />
+
+        <Button
+            android:id="@+id/grant_button"
+            style="@android:style/Widget.DeviceDefault.Button.Borderless"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:text="@string/request_permission_allow_button" />
+    </LinearLayout>
+</LinearLayout>

plugins/sdk/src/main/res/values/strings.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <string name="request_permission_message"><![CDATA[<b>%1$s</b> wants to access data from <b>%2$s</b>.]]></string>
+    <string name="request_permission_deny_button">Deny</string>
+    <string name="request_permission_allow_button">Allow</string>
+</resources>