From f81e11d51ca758037198249178ae86d2fb7b3792 Mon Sep 17 00:00:00 2001
From: Ashish Kumar <akgaurav@google.com>
Date: Wed, 1 Mar 2023 14:34:42 +0000
Subject: [PATCH] Restricting DocumentsProvider#getType by implementing
 getTypeAnonymous

  - getTypeAnonymous can be accessed by anyone. It does not reveal any sensitive information.

Bug: b/271262541
Test: build and manual test
Change-Id: I300a3be0904c44214f3ab206c30314855feaa57b
---
 core/api/current.txt                              |  1 +
 core/java/android/provider/DocumentsProvider.java | 13 +++++++++++++
 2 files changed, 14 insertions(+)

diff --git a/core/api/current.txt b/core/api/current.txt
index a7f69374ff008..600adde36063f 100644
--- a/core/api/current.txt
+++ b/core/api/current.txt
@@ -36849,6 +36849,7 @@ package android.provider {
     method public String[] getDocumentStreamTypes(String, String);
     method public String getDocumentType(String) throws java.io.FileNotFoundException;
     method public final String getType(android.net.Uri);
+    method @Nullable public final String getTypeAnonymous(@NonNull android.net.Uri);
     method public final android.net.Uri insert(android.net.Uri, android.content.ContentValues);
     method public boolean isChildDocument(String, String);
     method public String moveDocument(String, String, String) throws java.io.FileNotFoundException;
diff --git a/core/java/android/provider/DocumentsProvider.java b/core/java/android/provider/DocumentsProvider.java
index 07d500176fe5c..5b527c70b4f75 100644
--- a/core/java/android/provider/DocumentsProvider.java
+++ b/core/java/android/provider/DocumentsProvider.java
@@ -978,6 +978,19 @@ public abstract class DocumentsProvider extends ContentProvider {
         }
     }
 
+    /**
+     * An unrestricted version of getType, which does not reveal sensitive information
+     */
+    @Override
+    public final @Nullable String getTypeAnonymous(@NonNull Uri uri) {
+        switch (mMatcher.match(uri)) {
+            case MATCH_ROOT:
+                return DocumentsContract.Root.MIME_TYPE_ITEM;
+            default:
+                return null;
+        }
+    }
+
     /**
      * Implementation is provided by the parent class. Can be overridden to
      * provide additional functionality, but subclasses <em>must</em> always