DO NOT MERGE Take advantage of new MotionEvent flag to prevent tapjacking.

Ticket: CYNGNOS-2707
Bug: 26677796
Change-Id: I563541f0a42564b854af0f8037c1d4741c79a2ac
(cherry picked from commit b431433dabd769d0e1688a49dad100b7b65ff66b)

2 files changed, 58 insertions, 2 deletions

diff --git a/res/layout/grant_permissions.xml b/res/layout/grant_permissions.xml
index 463f0ccd..fe6389fe 100644
--- a/res/layout/grant_permissions.xml
+++ b/res/layout/grant_permissions.xml
@@ -91,14 +91,14 @@
                     android:text="@string/grant_dialog_button_deny" >
                 </Button>
 
-                <Button
+                <com.android.packageinstaller.permission.ui.SecureButtonView
                     android:id="@+id/permission_allow_button"
                     android:layout_width="wrap_content"
                     android:layout_height="wrap_content"
                     style="?android:attr/buttonBarButtonStyle"
                     android:layout_marginStart="8dip"
                     android:text="@string/grant_dialog_button_allow" >
-                </Button>
+                </com.android.packageinstaller.permission.ui.SecureButtonView>
 
             </LinearLayout>
 
diff --git a/src/com/android/packageinstaller/permission/ui/SecureButtonView.java b/src/com/android/packageinstaller/permission/ui/SecureButtonView.java
new file mode 100644
index 00000000..624744e5
--- /dev/null
+++ b/src/com/android/packageinstaller/permission/ui/SecureButtonView.java
@@ -0,0 +1,56 @@
+/*
+ * Copyright (C) 2016 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.packageinstaller.permission.ui;
+
+import android.content.Context;
+import android.util.AttributeSet;
+import android.view.MotionEvent;
+import android.widget.Button;
+
+/**
+ * Extension of Button that uses the hidden MotionEvent flag for partially obscured windows to
+ * prevent tapjacking attacks.
+ */
+public class SecureButtonView extends Button {
+
+    public SecureButtonView(Context context) {
+        this(context, null);
+    }
+
+    public SecureButtonView(Context context, AttributeSet attrs) {
+        this(context, attrs, 0);
+    }
+
+    public SecureButtonView(Context context, AttributeSet attrs, int defStyleAttr) {
+        this(context, attrs, defStyleAttr, 0);
+    }
+
+    public SecureButtonView(Context context, AttributeSet attrs, int defStyleAttr,
+            int defStyleRes) {
+        super(context, attrs, defStyleAttr, defStyleRes);
+    }
+
+    @Override
+    public boolean onFilterTouchEventForSecurity(MotionEvent event) {
+        if ((event.getFlags() & MotionEvent.FLAG_WINDOW_IS_OBSCURED) != 0
+                || (event.getFlags() & MotionEvent.FLAG_WINDOW_IS_PARTIALLY_OBSCURED) != 0) {
+            // Window is obscured, drop this touch.
+            return false;
+        }
+        return true;
+    }
+}