From 05c8eb5fd0e2dfe902217a3f6ffe570f8fb5af9f Mon Sep 17 00:00:00 2001
From: Suprabh Shukla <suprabh@google.com>
Date: Mon, 22 May 2017 15:20:06 -0700
Subject: [PATCH] Disabling the activate button when paused

This revises the previous attempt to drop taps when another window is
obscuring the device admin details. Any system alert windows or toasts
are disabled when the activity is in focus, otherwise the button is
disabled so no floating activities can obscure it and delegate taps back
to the security sensitive "Activate" button.

Test: CtsVerifier -> Device Administration -> Device Admin Tapjacking Test

Bug: 35056974
Change-Id: I292a44e713ea4a4b0305ca3b3b21f1c82fd73c2b
---
 src/com/android/settings/DeviceAdminAdd.java | 28 ++++++++++----------
 1 file changed, 14 insertions(+), 14 deletions(-)

diff --git a/src/com/android/settings/DeviceAdminAdd.java b/src/com/android/settings/DeviceAdminAdd.java
index fb2f29f5054..5978f5eded9 100644
--- a/src/com/android/settings/DeviceAdminAdd.java
+++ b/src/com/android/settings/DeviceAdminAdd.java
@@ -40,6 +40,7 @@ import android.net.Uri;
 import android.os.Binder;
 import android.os.Bundle;
 import android.os.Handler;
+import android.os.IBinder;
 import android.os.RemoteCallback;
 import android.os.RemoteException;
 import android.os.UserHandle;
@@ -90,6 +91,7 @@ public class DeviceAdminAdd extends Activity {
     public static final String EXTRA_CALLED_FROM_SUPPORT_DIALOG =
             "android.app.extra.CALLED_FROM_SUPPORT_DIALOG";
 
+    private final IBinder mToken = new Binder();
     Handler mHandler;
 
     DevicePolicyManager mDPM;
@@ -118,8 +120,6 @@ public class DeviceAdminAdd extends Activity {
     boolean mWaitingForRemoveMsg;
     boolean mAddingProfileOwner;
     boolean mAdminPoliciesInitialized;
-    int mCurSysAppOpMode;
-    int mCurToastAppOpMode;
 
     boolean mIsCalledFromSupportDialog = false;
 
@@ -352,6 +352,9 @@ public class DeviceAdminAdd extends Activity {
         restrictedAction.setFilterTouchesWhenObscured(true);
         restrictedAction.setOnClickListener(new View.OnClickListener() {
             public void onClick(View v) {
+                if (!mActionButton.isEnabled()) {
+                    return;
+                }
                 if (mAdding) {
                     addAndFinish();
                 } else if (isManagedProfile(mDeviceAdmin)
@@ -473,24 +476,21 @@ public class DeviceAdminAdd extends Activity {
     @Override
     protected void onResume() {
         super.onResume();
+        mActionButton.setEnabled(true);
         updateInterface();
-        // As long as we are running, don't let this admin overlay stuff on top of the screen.
-        final int uid = mDeviceAdmin.getActivityInfo().applicationInfo.uid;
-        final String pkg = mDeviceAdmin.getActivityInfo().applicationInfo.packageName;
-        mCurSysAppOpMode = mAppOps.checkOp(AppOpsManager.OP_SYSTEM_ALERT_WINDOW, uid, pkg);
-        mCurToastAppOpMode = mAppOps.checkOp(AppOpsManager.OP_TOAST_WINDOW, uid, pkg);
-        mAppOps.setMode(AppOpsManager.OP_SYSTEM_ALERT_WINDOW, uid, pkg, AppOpsManager.MODE_IGNORED);
-        mAppOps.setMode(AppOpsManager.OP_TOAST_WINDOW, uid, pkg, AppOpsManager.MODE_IGNORED);
+        // As long as we are running, don't let anyone overlay stuff on top of the screen.
+        mAppOps.setUserRestriction(AppOpsManager.OP_SYSTEM_ALERT_WINDOW, true, mToken);
+        mAppOps.setUserRestriction(AppOpsManager.OP_TOAST_WINDOW, true, mToken);
+
     }
 
     @Override
     protected void onPause() {
         super.onPause();
-        // As long as we are running, don't let this admin overlay stuff on top of the screen.
-        final int uid = mDeviceAdmin.getActivityInfo().applicationInfo.uid;
-        final String pkg = mDeviceAdmin.getActivityInfo().applicationInfo.packageName;
-        mAppOps.setMode(AppOpsManager.OP_SYSTEM_ALERT_WINDOW, uid, pkg, mCurSysAppOpMode);
-        mAppOps.setMode(AppOpsManager.OP_TOAST_WINDOW, uid, pkg, mCurToastAppOpMode);
+        // This just greys out the button. The actual listener is attached to R.id.restricted_action
+        mActionButton.setEnabled(false);
+        mAppOps.setUserRestriction(AppOpsManager.OP_SYSTEM_ALERT_WINDOW, false, mToken);
+        mAppOps.setUserRestriction(AppOpsManager.OP_TOAST_WINDOW, false, mToken);
         try {
             ActivityManager.getService().resumeAppSwitches();
         } catch (RemoteException e) {