From 5c5afc5603835ec73e16e10703416fa52222af33 Mon Sep 17 00:00:00 2001
From: Ted Bauer <tedbauer@google.com>
Date: Wed, 29 Mar 2023 14:25:14 +0000
Subject: [PATCH] Add namespace-level flag-write allowlist.

Also migrate some tests to allowlisted functionality, that exercise the
namespace flag-write allowlist.

Test: Presubmits
Bug: 273546621
Change-Id: I686dfd3c11b0e49f94cc46b3d009107c0a3b8e1a
---
 core/tests/coretests/AndroidManifest.xml      |  3 +-
 .../src/com/android/providers/settings/OWNERS |  1 +
 .../providers/settings/SettingsProvider.java  | 10 ++++-
 .../settings/WritableNamespacePrefixes.java   | 39 +++++++++++++++++++
 4 files changed, 51 insertions(+), 2 deletions(-)
 create mode 100644 packages/SettingsProvider/src/com/android/providers/settings/OWNERS
 create mode 100644 packages/SettingsProvider/src/com/android/providers/settings/WritableNamespacePrefixes.java

diff --git a/core/tests/coretests/AndroidManifest.xml b/core/tests/coretests/AndroidManifest.xml
index bf8ca8bc37641..4cccf8e49890f 100644
--- a/core/tests/coretests/AndroidManifest.xml
+++ b/core/tests/coretests/AndroidManifest.xml
@@ -76,7 +76,8 @@
     <uses-permission android:name="android.permission.USE_CREDENTIALS" />
     <uses-permission android:name="android.permission.WAKE_LOCK" />
     <uses-permission android:name="android.permission.WRITE_CONTACTS" />
-    <uses-permission android:name="android.permission.WRITE_DEVICE_CONFIG" />
+    <uses-permission android:name="android.permission.READ_WRITE_SYNC_DISABLED_MODE_CONFIG" />
+    <uses-permission android:name="android.permission.WRITE_ALLOWLISTED_DEVICE_CONFIG" />
     <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
     <uses-permission android:name="android.permission.WRITE_SETTINGS" />
     <uses-permission android:name="android.permission.WRITE_SECURE_SETTINGS" />
diff --git a/packages/SettingsProvider/src/com/android/providers/settings/OWNERS b/packages/SettingsProvider/src/com/android/providers/settings/OWNERS
new file mode 100644
index 0000000000000..0b71816062478
--- /dev/null
+++ b/packages/SettingsProvider/src/com/android/providers/settings/OWNERS
@@ -0,0 +1 @@
+per-file WritableNamespacePrefixes.java = cbrubaker@google.com,tedbauer@google.com
diff --git a/packages/SettingsProvider/src/com/android/providers/settings/SettingsProvider.java b/packages/SettingsProvider/src/com/android/providers/settings/SettingsProvider.java
index 5a8c59489ec84..3e1b597094d2e 100644
--- a/packages/SettingsProvider/src/com/android/providers/settings/SettingsProvider.java
+++ b/packages/SettingsProvider/src/com/android/providers/settings/SettingsProvider.java
@@ -2323,7 +2323,15 @@ public class SettingsProvider extends ContentProvider {
             return;
         } else if (hasAllowlistPermission) {
             for (String flag : flags) {
-                if (!DeviceConfig.getAdbWritableFlags().contains(flag)) {
+                boolean namespaceAllowed = false;
+                for (String allowlistedPrefix : WritableNamespacePrefixes.ALLOWLIST) {
+                    if (flag.startsWith(allowlistedPrefix)) {
+                        namespaceAllowed = true;
+                        break;
+                    }
+                }
+
+                if (!namespaceAllowed && !DeviceConfig.getAdbWritableFlags().contains(flag)) {
                     throw new SecurityException("Permission denial for flag '"
                         + flag
                         + "'; allowlist permission granted, but must add flag to the allowlist.");
diff --git a/packages/SettingsProvider/src/com/android/providers/settings/WritableNamespacePrefixes.java b/packages/SettingsProvider/src/com/android/providers/settings/WritableNamespacePrefixes.java
new file mode 100644
index 0000000000000..28f25e0cc407e
--- /dev/null
+++ b/packages/SettingsProvider/src/com/android/providers/settings/WritableNamespacePrefixes.java
@@ -0,0 +1,39 @@
+/*
+ * Copyright (C) 2007 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.providers.settings;
+
+import android.util.ArraySet;
+
+import java.util.Arrays;
+import java.util.Set;
+
+/**
+ * Contains the list of prefixes for namespaces in which any flag can be written with adb.
+ * <p>
+ * A security review is required for any prefix that's added to this list. To add to
+ * the list, create a change and tag the OWNER. In the change description, include a
+ * description of the flag's functionality, and a justification for why it needs to be
+ * allowlisted.
+ */
+final class WritableNamespacePrefixes {
+    public static final Set<String> ALLOWLIST =
+            new ArraySet<String>(Arrays.asList(
+                "app_compat_overrides",
+                "game_overlay",
+                "namespace1"
+            ));
+}