AOSP/UnifiedEmail - Secure UPDATE_WIDGET receiver with a new permission

The update methods sends a broadcast with the account name, the folder, etc.
This implicitly bypasses the GET_ACCOUNT permission if a third-party
applications listens to this broadcast.

- Introduce a new app permission
- com.android.email.permission.GET_WIDGET_UPDATE
- Now the com.android.email.permission.GET_WIDGET_UPDATE is required to
- receive the emitted broadcast
- Add this permission to our existing widgets.

Ported changes from cr/106302205
- added uses-permission GET_WIDGET_UPDATE, so Gmail app has the permission to receive the intent

Bug: 139803872

Test: manual - Ran the following tests on Pixel phone. Tested the email UI.

$ make -j 40
$ make Email -j
$ make EmailTests -j
  -rw-r--r-- 1 rtenneti primarygroup 6356400 Sep 16 14:10 out/target/product/marlin/testcases/Email/arm64/Email.apk
  -rw-r--r-- 1 rtenneti primarygroup 389599 Sep 16 14:18 out/target/product/marlin/testcases/EmailTests/arm64/EmailTests.apk

$ adb install -r -d -g out/target/product/marlin/testcases/Email/arm64/Email.apk
$ adb install -r -d -g out/target/product/marlin/testcases/EmailTests/arm64/EmailTests.apk
$ adb shell am instrument -w com.android.email.tests
  Time: 34.746
  OK (157 tests)

$ atest EmailTests
  Summary
  -------
  EmailTests: Passed: 157, Failed: 0, Ignored: 0, Assumption Failed: 0

  All tests passed!

$ adb install ../security_attack/bug_139803872/poc.apk
  Captured the logcat output at rtenneti's x20web logcat.out.0916.1503
  while reproducting the steps in b/139803872#comment3

Change-Id: Ied292eab76c672c60de57f8ce43df0e0ea6d3464

2 files changed, 18 insertions, 3 deletions

diff --git a/res/values/strings.xml b/res/values/strings.xml
index 951f1070c..a8b7bfef9 100644
--- a/res/values/strings.xml
+++ b/res/values/strings.xml
@@ -26,6 +26,13 @@
 
     <string name="app_name" translatable="false">Unified Email</string>
 
+    <!-- The name of the permission to get widget update notifications. -->
+    <string name="permission_update_widget" translatable="false">com.android.email.permission.GET_WIDGET_UPDATE</string>
+    <!-- Permission label for receiving updates for the widget. -->
+    <string name="permission_update_widget_label">Update widget</string>
+    <!-- Permission description for receiving updates for the widget. -->
+    <string name="permission_update_widget_desc">Allows the app to receive notifications when the widget should be refreshed, including the account name and folder name.</string>
+
     <!-- Compose -->
     <!-- Shown in Compose; the sender of the message [CHAR LIMIT=10] -->
     <string name="from">From</string>
diff --git a/src/com/android/mail/widget/BaseWidgetProvider.java b/src/com/android/mail/widget/BaseWidgetProvider.java
index 00eacd79b..42d1ae634 100644
--- a/src/com/android/mail/widget/BaseWidgetProvider.java
+++ b/src/com/android/mail/widget/BaseWidgetProvider.java
@@ -318,10 +318,18 @@ public abstract class BaseWidgetProvider extends AppWidgetProvider {
         updateWidgetIntent.putExtra(EXTRA_FOLDER_TYPE, folderType);
         updateWidgetIntent.putExtra(EXTRA_FOLDER_CAPABILITIES, folderCapabilities);
         updateWidgetIntent.putExtra(EXTRA_FOLDER_URI, folderUri);
-        updateWidgetIntent.putExtra(EXTRA_FOLDER_CONVERSATION_LIST_URI, folderConversationListUri);
-        updateWidgetIntent.putExtra(EXTRA_FOLDER_DISPLAY_NAME, folderDisplayName);
 
-        context.sendBroadcast(updateWidgetIntent);
+        if (folderConversationListUri != null) {
+            updateWidgetIntent.putExtra(EXTRA_FOLDER_CONVERSATION_LIST_URI,
+                    folderConversationListUri);
+        }
+        if (folderDisplayName != null) {
+            updateWidgetIntent.putExtra(EXTRA_FOLDER_DISPLAY_NAME, folderDisplayName);
+        }
+        updateWidgetIntent.setPackage(context.getPackageName());
+
+        context.sendBroadcast(updateWidgetIntent,
+                context.getString(R.string.permission_update_widget));
     }
 
     public static void validateAllWidgets(Context context, String accountMimeType) {