intent gatekeeper initial

2026-04-19 02:23:04 +02:00
parent 5e6cc7a0f1
commit 57c3dcca86
27 changed files with 1413 additions and 12 deletions
@@ -0,0 +1,53 @@
+/*
+ * Copyright (c) 2024-2026 Fabian Freund.
+ *
+ * This file is part of WebLibre
+ * (see https://weblibre.eu).
+ */
+package eu.weblibre.simple_intent_receiver
+
+import android.content.Context
+import android.content.pm.PackageManager
+import android.os.Build
+import eu.weblibre.simple_intent_receiver.pigeons.IntentGatekeeperHostApi
+
+/**
+ * Persists the Flutter-side gatekeeper policy to a shared-prefs file that
+ * [eu.weblibre.flutter_mozilla_components.activities.IntentReceiverActivity]
+ * reads on each incoming intent.
+ *
+ * The prefs file name MUST match
+ * [eu.weblibre.flutter_mozilla_components.gatekeeper.IntentGatekeeperPreferences.PREFS_NAME].
+ */
+class IntentGatekeeperHostApiImpl(private val context: Context) : IntentGatekeeperHostApi {
+    companion object {
+        private const val PREFS_NAME = "weblibre_intent_gatekeeper"
+        private const val KEY_ENABLED = "enabled"
+        private const val KEY_BLOCKED_PACKAGES = "blocked_packages"
+    }
+
+    override fun setConfig(enabled: Boolean, blockedPackages: List<String>) {
+        val prefs = context.applicationContext.getSharedPreferences(PREFS_NAME, Context.MODE_PRIVATE)
+        prefs.edit()
+            .putBoolean(KEY_ENABLED, enabled)
+            .putStringSet(KEY_BLOCKED_PACKAGES, blockedPackages.toSet())
+            .apply()
+    }
+
+    override fun resolvePackageLabel(packageName: String): String? {
+        return try {
+            val pm = context.applicationContext.packageManager
+            val info = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
+                pm.getApplicationInfo(packageName, PackageManager.ApplicationInfoFlags.of(0))
+            } else {
+                @Suppress("DEPRECATION")
+                pm.getApplicationInfo(packageName, 0)
+            }
+            pm.getApplicationLabel(info).toString()
+        } catch (_: PackageManager.NameNotFoundException) {
+            null
+        } catch (_: Exception) {
+            null
+        }
+    }
+}
@@ -22,7 +22,10 @@ package eu.weblibre.simple_intent_receiver
 import android.app.Activity
 import android.content.Context
 import android.content.Intent
+import android.content.pm.ApplicationInfo
+import android.content.pm.PackageManager
 import android.net.Uri
+import android.os.Build
 import android.os.Bundle
 import io.flutter.Log
 import io.flutter.embedding.engine.plugins.FlutterPlugin
@@ -30,20 +33,29 @@ import io.flutter.embedding.engine.plugins.activity.ActivityAware
 import io.flutter.embedding.engine.plugins.activity.ActivityPluginBinding
 import io.flutter.plugin.common.PluginRegistry
 import eu.weblibre.simple_intent_receiver.pigeons.Intent as PigeonIntent
+import eu.weblibre.simple_intent_receiver.pigeons.IntentGatekeeperHostApi

 class SimpleIntentReceiverPlugin: FlutterPlugin, ActivityAware, PluginRegistry.NewIntentListener {
  private lateinit var context: Context
  private var intentReceiver: IntentReceiver? = null
  private var lastHandledIntent: String? = null
  private var activity: Activity? = null
+  private var binaryMessenger: io.flutter.plugin.common.BinaryMessenger? = null

  override fun onAttachedToEngine(flutterPluginBinding: FlutterPlugin.FlutterPluginBinding) {
    context = flutterPluginBinding.applicationContext
    intentReceiver = IntentReceiver(flutterPluginBinding.binaryMessenger)
+    binaryMessenger = flutterPluginBinding.binaryMessenger
+    IntentGatekeeperHostApi.setUp(
+      flutterPluginBinding.binaryMessenger,
+      IntentGatekeeperHostApiImpl(flutterPluginBinding.applicationContext),
+    )
  }

  override fun onDetachedFromEngine(binding: FlutterPlugin.FlutterPluginBinding) {
    intentReceiver = null
+    binaryMessenger?.let { IntentGatekeeperHostApi.setUp(it, null) }
+    binaryMessenger = null
  }

  override fun onAttachedToActivity(binding: ActivityPluginBinding) {
@@ -118,10 +130,59 @@ class SimpleIntentReceiverPlugin: FlutterPlugin, ActivityAware, PluginRegistry.N
    return true
  }

+  private fun resolveCallerPackage(intent: Intent): String? {
+    val raw = resolveRawCallerPackage(intent) ?: return null
+    // Treat system packages (launcher, shell, SystemUI, etc.) as internal — the
+    // gatekeeper shouldn't prompt the user when the OS itself forwards an intent.
+    if (isSystemPackage(raw)) return null
+    return raw
+  }
+
+  private fun resolveRawCallerPackage(intent: Intent): String? {
+    // 1. Try Activity.getReferrer() — handles EXTRA_REFERRER/_NAME and real caller.
+    activity?.referrer?.let { uri ->
+      if (uri.scheme == "android-app") {
+        uri.host?.let { return it }
+      }
+    }
+
+    // 2. Fallback to explicit referrer extras on the intent itself.
+    @Suppress("DEPRECATION")
+    val referrerUri: Uri? = intent.getParcelableExtra(Intent.EXTRA_REFERRER)
+    if (referrerUri?.scheme == "android-app") {
+      referrerUri.host?.let { return it }
+    }
+
+    intent.getStringExtra(Intent.EXTRA_REFERRER_NAME)?.let { name ->
+      Uri.parse(name).takeIf { it.scheme == "android-app" }?.host?.let { return it }
+    }
+
+    // 3. Caller for startActivityForResult flows.
+    return activity?.callingPackage
+  }
+
+  private fun isSystemPackage(packageName: String): Boolean {
+    return try {
+      val pm = context.packageManager
+      val info = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
+        pm.getApplicationInfo(packageName, PackageManager.ApplicationInfoFlags.of(0))
+      } else {
+        @Suppress("DEPRECATION")
+        pm.getApplicationInfo(packageName, 0)
+      }
+      val systemFlags = ApplicationInfo.FLAG_SYSTEM or ApplicationInfo.FLAG_UPDATED_SYSTEM_APP
+      (info.flags and systemFlags) != 0
+    } catch (_: PackageManager.NameNotFoundException) {
+      false
+    } catch (_: Exception) {
+      false
+    }
+  }
+
  private fun convertToPigeonIntent(intent: Intent): PigeonIntent {
    val action = intent.action
    val data = intent.dataString
-    val fromPackageName = intent.getPackage()
+    val fromPackageName = resolveCallerPackage(intent)

    val categories = ArrayList<String>()
    intent.categories?.let {
@@ -17,6 +17,26 @@ private object IntentPigeonUtils {

  fun createConnectionError(channelName: String): FlutterError {
    return FlutterError("channel-error",  "Unable to establish connection on channel: '$channelName'.", "")  }
+
+  fun wrapResult(result: Any?): List<Any?> {
+    return listOf(result)
+  }
+
+  fun wrapError(exception: Throwable): List<Any?> {
+    return if (exception is FlutterError) {
+      listOf(
+        exception.code,
+        exception.message,
+        exception.details
+      )
+    } else {
+      listOf(
+        exception.javaClass.simpleName,
+        exception.toString(),
+        "Cause: " + exception.cause + ", Stacktrace: " + Log.getStackTraceString(exception)
+      )
+    }
+  }
  fun doubleEquals(a: Double, b: Double): Boolean {
    // Normalize -0.0 to 0.0 and handle NaN equality.
    return (if (a == 0.0) 0.0 else a) == (if (b == 0.0) 0.0 else b) || (a.isNaN() && b.isNaN())
@@ -276,3 +296,65 @@ class IntentEvents(private val binaryMessenger: BinaryMessenger, private val mes
    }
  }
 }
+/** Generated interface from Pigeon that represents a handler of messages from Flutter. */
+interface IntentGatekeeperHostApi {
+  /**
+   * Replicates the blocked-packages policy to the native side so the
+   * [IntentReceiverActivity] can reject intents without launching Flutter.
+   */
+  fun setConfig(enabled: Boolean, blockedPackages: List<String>)
+  /**
+   * Resolves a package name to its user-visible application label via
+   * [PackageManager]. Returns `null` if the package is not installed or the
+   * label cannot be resolved.
+   */
+  fun resolvePackageLabel(packageName: String): String?
+
+  companion object {
+    /** The codec used by IntentGatekeeperHostApi. */
+    val codec: MessageCodec<Any?> by lazy {
+      IntentPigeonCodec()
+    }
+    /** Sets up an instance of `IntentGatekeeperHostApi` to handle messages through the `binaryMessenger`. */
+    @JvmOverloads
+    fun setUp(binaryMessenger: BinaryMessenger, api: IntentGatekeeperHostApi?, messageChannelSuffix: String = "") {
+      val separatedMessageChannelSuffix = if (messageChannelSuffix.isNotEmpty()) ".$messageChannelSuffix" else ""
+      run {
+        val channel = BasicMessageChannel<Any?>(binaryMessenger, "dev.flutter.pigeon.simple_intent_receiver.IntentGatekeeperHostApi.setConfig$separatedMessageChannelSuffix", codec)
+        if (api != null) {
+          channel.setMessageHandler { message, reply ->
+            val args = message as List<Any?>
+            val enabledArg = args[0] as Boolean
+            val blockedPackagesArg = args[1] as List<String>
+            val wrapped: List<Any?> = try {
+              api.setConfig(enabledArg, blockedPackagesArg)
+              listOf(null)
+            } catch (exception: Throwable) {
+              IntentPigeonUtils.wrapError(exception)
+            }
+            reply.reply(wrapped)
+          }
+        } else {
+          channel.setMessageHandler(null)
+        }
+      }
+      run {
+        val channel = BasicMessageChannel<Any?>(binaryMessenger, "dev.flutter.pigeon.simple_intent_receiver.IntentGatekeeperHostApi.resolvePackageLabel$separatedMessageChannelSuffix", codec)
+        if (api != null) {
+          channel.setMessageHandler { message, reply ->
+            val args = message as List<Any?>
+            val packageNameArg = args[0] as String
+            val wrapped: List<Any?> = try {
+              listOf(api.resolvePackageLabel(packageNameArg))
+            } catch (exception: Throwable) {
+              IntentPigeonUtils.wrapError(exception)
+            }
+            reply.reply(wrapped)
+          }
+        } else {
+          channel.setMessageHandler(null)
+        }
+      }
+    }
+  }
+}