Add Sideloaded detector

A helper class to detect if any package is unsafe or sideloaded.
A package is considered unsafe if not a system app and not installed
through trusted sources.
The usage will be added in the following cls.

Bug: 154263570
Test: Added UnitTest
Change-Id: Ifffbe64ae95029427aeca4a997bc440dbdc2d3d6

3 files changed, 305 insertions, 0 deletions

diff --git a/packages/CarSystemUI/res/values/config.xml b/packages/CarSystemUI/res/values/config.xml
index bf1bf38cdb92..5679306b3001 100644
--- a/packages/CarSystemUI/res/values/config.xml
+++ b/packages/CarSystemUI/res/values/config.xml
@@ -76,6 +76,11 @@
         <item>com.android.systemui.car.userswitcher.FullscreenUserSwitcherViewMediator</item>
     </string-array>
 
+    <!-- List of package names that are allowed sources of app installation. -->
+    <string-array name="config_allowedAppInstallSources" translatable="false">
+        <item>com.android.vending</item>
+    </string-array>
+
     <!-- SystemUI Services: The classes of the stuff to start. -->
     <string-array name="config_systemUIServiceComponents" translatable="false">
         <item>com.android.systemui.util.NotificationChannels</item>
diff --git a/packages/CarSystemUI/src/com/android/systemui/sideloaded/car/CarSideLoadedAppDetector.java b/packages/CarSystemUI/src/com/android/systemui/sideloaded/car/CarSideLoadedAppDetector.java
new file mode 100644
index 000000000000..c0dbb5879d7d
--- /dev/null
+++ b/packages/CarSystemUI/src/com/android/systemui/sideloaded/car/CarSideLoadedAppDetector.java
@@ -0,0 +1,136 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.systemui.sideloaded.car;
+
+import android.annotation.NonNull;
+import android.app.ActivityManager;
+import android.content.ComponentName;
+import android.content.pm.ApplicationInfo;
+import android.content.pm.InstallSourceInfo;
+import android.content.pm.PackageInfo;
+import android.content.pm.PackageManager;
+import android.content.res.Resources;
+import android.os.UserHandle;
+import android.util.Log;
+
+import com.android.systemui.R;
+import com.android.systemui.car.CarDeviceProvisionedController;
+import com.android.systemui.dagger.qualifiers.Main;
+
+import java.util.Arrays;
+import java.util.List;
+
+import javax.inject.Inject;
+import javax.inject.Singleton;
+
+/**
+ * A class that detects unsafe apps.
+ * An app is considered safe if is a system app or installed through whitelisted sources.
+ */
+@Singleton
+public class CarSideLoadedAppDetector {
+    private static final String TAG = "CarSideLoadedDetector";
+
+    private final PackageManager mPackageManager;
+    private final CarDeviceProvisionedController mCarDeviceProvisionedController;
+    private final List<String> mAllowedAppInstallSources;
+
+    @Inject
+    public CarSideLoadedAppDetector(@Main Resources resources, PackageManager packageManager,
+            CarDeviceProvisionedController deviceProvisionedController) {
+        mAllowedAppInstallSources = Arrays.asList(
+                resources.getStringArray(R.array.config_allowedAppInstallSources));
+        mPackageManager = packageManager;
+        mCarDeviceProvisionedController = deviceProvisionedController;
+    }
+
+    boolean hasUnsafeInstalledApps() {
+        int userId = mCarDeviceProvisionedController.getCurrentUser();
+
+        List<PackageInfo> packages = mPackageManager.getInstalledPackagesAsUser(
+                PackageManager.MATCH_DIRECT_BOOT_AWARE
+                        | PackageManager.MATCH_DIRECT_BOOT_UNAWARE,
+                userId);
+        for (PackageInfo info : packages) {
+            if (info.applicationInfo == null) {
+                Log.w(TAG, info.packageName + " does not have application info.");
+                return true;
+            }
+
+            if (!isSafe(info.applicationInfo)) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    boolean isSafe(@NonNull ActivityManager.StackInfo stackInfo) {
+        ComponentName componentName = stackInfo.topActivity;
+        if (componentName == null) {
+            Log.w(TAG, "Stack info does not have top activity: " + stackInfo.stackId);
+            return false;
+        }
+        return isSafe(componentName.getPackageName());
+    }
+
+    private boolean isSafe(@NonNull String packageName) {
+        if (packageName == null) {
+            return false;
+        }
+
+        ApplicationInfo applicationInfo;
+        try {
+            int userId = mCarDeviceProvisionedController.getCurrentUser();
+            applicationInfo = mPackageManager.getApplicationInfoAsUser(packageName,
+                    PackageManager.MATCH_DIRECT_BOOT_AWARE
+                            | PackageManager.MATCH_DIRECT_BOOT_UNAWARE,
+                    UserHandle.of(userId));
+
+            if (applicationInfo == null) {
+                Log.e(TAG, packageName + " did not have an application info!");
+                return false;
+            }
+        } catch (PackageManager.NameNotFoundException e) {
+            Log.e(TAG, "Could not get application info for package:" + packageName, e);
+            return false;
+        }
+
+        return isSafe(applicationInfo);
+    }
+
+    private boolean isSafe(@NonNull ApplicationInfo applicationInfo) {
+        String packageName = applicationInfo.packageName;
+
+        if (applicationInfo.isSystemApp() || applicationInfo.isUpdatedSystemApp()) {
+            return true;
+        }
+
+        String initiatingPackageName;
+        try {
+            InstallSourceInfo sourceInfo = mPackageManager.getInstallSourceInfo(packageName);
+            initiatingPackageName = sourceInfo.getInitiatingPackageName();
+            if (initiatingPackageName == null) {
+                Log.w(TAG, packageName + " does not have an installer name.");
+                return false;
+            }
+
+            return mAllowedAppInstallSources.contains(initiatingPackageName);
+        } catch (IllegalArgumentException | PackageManager.NameNotFoundException e) {
+            return false;
+        }
+    }
+}
diff --git a/packages/CarSystemUI/tests/src/com/android/systemui/sideloaded/car/CarSideLoadedAppDetectorTest.java b/packages/CarSystemUI/tests/src/com/android/systemui/sideloaded/car/CarSideLoadedAppDetectorTest.java
new file mode 100644
index 000000000000..aebb0e005019
--- /dev/null
+++ b/packages/CarSystemUI/tests/src/com/android/systemui/sideloaded/car/CarSideLoadedAppDetectorTest.java
@@ -0,0 +1,164 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.systemui.sideloaded.car;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.anyInt;
+import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.Mockito.when;
+
+import android.app.ActivityManager;
+import android.content.ComponentName;
+import android.content.pm.ApplicationInfo;
+import android.content.pm.InstallSourceInfo;
+import android.content.pm.PackageManager;
+import android.testing.AndroidTestingRunner;
+import android.testing.TestableLooper;
+import android.testing.TestableResources;
+
+import androidx.test.filters.SmallTest;
+
+import com.android.systemui.R;
+import com.android.systemui.SysuiTestCase;
+import com.android.systemui.car.CarDeviceProvisionedController;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+
+@RunWith(AndroidTestingRunner.class)
+@TestableLooper.RunWithLooper
+@SmallTest
+public class CarSideLoadedAppDetectorTest extends SysuiTestCase {
+
+    private static final String SAFE_VENDOR = "com.safe.vendor";
+    private static final String UNSAFE_VENDOR = "com.unsafe.vendor";
+    private static final String APP_PACKAGE_NAME = "com.test";
+    private static final String APP_CLASS_NAME = ".TestClass";
+
+    private CarSideLoadedAppDetector mSideLoadedAppDetector;
+
+    @Mock
+    private PackageManager mPackageManager;
+    @Mock
+    private CarDeviceProvisionedController mCarDeviceProvisionedController;
+
+    @Before
+    public void setUp() throws Exception {
+        MockitoAnnotations.initMocks(this);
+
+        TestableResources testableResources = mContext.getOrCreateTestableResources();
+        String[] allowedAppInstallSources = new String[] {SAFE_VENDOR};
+        testableResources.addOverride(R.array.config_allowedAppInstallSources,
+                allowedAppInstallSources);
+
+        mSideLoadedAppDetector = new CarSideLoadedAppDetector(testableResources.getResources(),
+                mPackageManager,
+                mCarDeviceProvisionedController);
+    }
+
+    @Test
+    public void isSafe_systemApp_returnsTrue() throws Exception {
+        ActivityManager.StackInfo stackInfo = new ActivityManager.StackInfo();
+        stackInfo.topActivity = new ComponentName(APP_PACKAGE_NAME, APP_CLASS_NAME);
+
+        ApplicationInfo applicationInfo = new ApplicationInfo();
+        applicationInfo.packageName = APP_PACKAGE_NAME;
+        applicationInfo.flags = ApplicationInfo.FLAG_SYSTEM;
+
+        when(mPackageManager.getApplicationInfoAsUser(eq(APP_PACKAGE_NAME), anyInt(), any()))
+                .thenReturn(applicationInfo);
+
+        assertThat(mSideLoadedAppDetector.isSafe(stackInfo)).isTrue();
+    }
+
+    @Test
+    public void isSafe_updatedSystemApp_returnsTrue() throws Exception {
+        ActivityManager.StackInfo stackInfo = new ActivityManager.StackInfo();
+        stackInfo.topActivity = new ComponentName(APP_PACKAGE_NAME, APP_CLASS_NAME);
+
+        ApplicationInfo applicationInfo = new ApplicationInfo();
+        applicationInfo.packageName = APP_PACKAGE_NAME;
+        applicationInfo.flags = ApplicationInfo.FLAG_UPDATED_SYSTEM_APP;
+
+        when(mPackageManager.getApplicationInfoAsUser(eq(APP_PACKAGE_NAME), anyInt(), any()))
+                .thenReturn(applicationInfo);
+
+        assertThat(mSideLoadedAppDetector.isSafe(stackInfo)).isTrue();
+    }
+
+    @Test
+    public void isSafe_nonSystemApp_withSafeSource_returnsTrue() throws Exception {
+        InstallSourceInfo sourceInfo = new InstallSourceInfo(SAFE_VENDOR,
+                /* initiatingPackageSigningInfo= */null,
+                /* originatingPackageName= */ null,
+                /* installingPackageName= */ null);
+        ActivityManager.StackInfo stackInfo = new ActivityManager.StackInfo();
+        stackInfo.topActivity = new ComponentName(APP_PACKAGE_NAME, APP_CLASS_NAME);
+
+        ApplicationInfo applicationInfo = new ApplicationInfo();
+        applicationInfo.packageName = APP_PACKAGE_NAME;
+
+        when(mPackageManager.getApplicationInfoAsUser(eq(APP_PACKAGE_NAME), anyInt(), any()))
+                .thenReturn(applicationInfo);
+        when(mPackageManager.getInstallSourceInfo(APP_PACKAGE_NAME)).thenReturn(sourceInfo);
+
+        assertThat(mSideLoadedAppDetector.isSafe(stackInfo)).isTrue();
+    }
+
+    @Test
+    public void isSafe_nonSystemApp_withUnsafeSource_returnsFalse() throws Exception {
+        InstallSourceInfo sourceInfo = new InstallSourceInfo(UNSAFE_VENDOR,
+                /* initiatingPackageSigningInfo= */null,
+                /* originatingPackageName= */ null,
+                /* installingPackageName= */ null);
+        ActivityManager.StackInfo stackInfo = new ActivityManager.StackInfo();
+        stackInfo.topActivity = new ComponentName(APP_PACKAGE_NAME, APP_CLASS_NAME);
+
+        ApplicationInfo applicationInfo = new ApplicationInfo();
+        applicationInfo.packageName = APP_PACKAGE_NAME;
+
+        when(mPackageManager.getApplicationInfoAsUser(eq(APP_PACKAGE_NAME), anyInt(), any()))
+                .thenReturn(applicationInfo);
+        when(mPackageManager.getInstallSourceInfo(APP_PACKAGE_NAME)).thenReturn(sourceInfo);
+
+        assertThat(mSideLoadedAppDetector.isSafe(stackInfo)).isFalse();
+    }
+
+    @Test
+    public void isSafe_nonSystemApp_withoutSource_returnsFalse() throws Exception {
+        InstallSourceInfo sourceInfo = new InstallSourceInfo(null,
+                /* initiatingPackageSigningInfo= */null,
+                /* originatingPackageName= */ null,
+                /* installingPackageName= */ null);
+        ActivityManager.StackInfo stackInfo = new ActivityManager.StackInfo();
+        stackInfo.topActivity = new ComponentName(APP_PACKAGE_NAME, APP_CLASS_NAME);
+
+        ApplicationInfo applicationInfo = new ApplicationInfo();
+        applicationInfo.packageName = APP_PACKAGE_NAME;
+
+        when(mPackageManager.getApplicationInfoAsUser(eq(APP_PACKAGE_NAME), anyInt(), any()))
+                .thenReturn(applicationInfo);
+        when(mPackageManager.getInstallSourceInfo(APP_PACKAGE_NAME)).thenReturn(sourceInfo);
+
+        assertThat(mSideLoadedAppDetector.isSafe(stackInfo)).isFalse();
+    }
+}