From 8947def237dc1ad11bfcc8a0c9172d4093f1b186 Mon Sep 17 00:00:00 2001
From: felkachang <felkachang@google.com>
Date: Fri, 1 Jul 2022 15:18:10 +0800
Subject: [PATCH] Prevent overlayable resources from being obfuscated

Once the build process finds one overlayable resource entry is not in
the list of collapse name exemption, the build process outputs the
resource name automatically and gives a warning message to notify the
developers.

Bug: 228192695

Test: atest aapt2_test
Change-Id: I989b75343d803b059c902baa088590fce7237211
---
 tools/aapt2/format/binary/TableFlattener.cpp  | 18 ++++++-
 .../format/binary/TableFlattener_test.cpp     | 48 +++++++++++++++++++
 2 files changed, 65 insertions(+), 1 deletion(-)

diff --git a/tools/aapt2/format/binary/TableFlattener.cpp b/tools/aapt2/format/binary/TableFlattener.cpp
index cd07b1ebbf924..46a846bce35fc 100644
--- a/tools/aapt2/format/binary/TableFlattener.cpp
+++ b/tools/aapt2/format/binary/TableFlattener.cpp
@@ -641,7 +641,23 @@ class PackageFlattener {
           local_key_index = (uint32_t)key_pool_.MakeRef(entry.name).index();
         } else {
           // resource isn't exempt from collapse, add it as obfuscated value
-          local_key_index = (uint32_t)key_pool_.MakeRef(obfuscated_resource_name).index();
+          if (entry.overlayable_item) {
+            // if the resource name of the specific entry is obfuscated and this
+            // entry is in the overlayable list, the overlay can't work on this
+            // overlayable at runtime because the name has been obfuscated in
+            // resources.arsc during flatten operation.
+            const OverlayableItem& item = entry.overlayable_item.value();
+            context_->GetDiagnostics()->Warn(android::DiagMessage(item.overlayable->source)
+                                             << "The resource name of overlayable entry "
+                                             << resource_name.to_string() << "'"
+                                             << " shouldn't be obfuscated in resources.arsc");
+
+            local_key_index = (uint32_t)key_pool_.MakeRef(entry.name).index();
+          } else {
+            // TODO(b/228192695): output the entry.name and Resource id to make
+            //  de-obfuscated possible.
+            local_key_index = (uint32_t)key_pool_.MakeRef(obfuscated_resource_name).index();
+          }
         }
         // Group values by configuration.
         for (auto& config_value : entry.values) {
diff --git a/tools/aapt2/format/binary/TableFlattener_test.cpp b/tools/aapt2/format/binary/TableFlattener_test.cpp
index 1dd2468b58683..e48fca61fef80 100644
--- a/tools/aapt2/format/binary/TableFlattener_test.cpp
+++ b/tools/aapt2/format/binary/TableFlattener_test.cpp
@@ -878,4 +878,52 @@ TEST_F(TableFlattenerTest, FlattenCustomResourceTypes) {
                      Res_value::TYPE_STRING, (uint32_t)*idx, 0u));
 }
 
+TEST_F(TableFlattenerTest, FlattenTypeEntryWithNameCollapseNotInExemption) {
+  OverlayableItem overlayable_item(std::make_shared<Overlayable>("TestName", "overlay://theme"));
+  overlayable_item.policies |= PolicyFlags::PUBLIC;
+
+  std::string name = "com.app.test:color/overlayable_color";
+  std::unique_ptr<ResourceTable> table =
+      test::ResourceTableBuilder()
+          .AddValue("com.app.test:color/overlayable_color", ResourceId(0x7f010000),
+                    util::make_unique<BinaryPrimitive>(uint8_t(Res_value::TYPE_INT_COLOR_ARGB8),
+                                                       0xffaabbcc))
+          .SetOverlayable(name, overlayable_item)
+          .Build();
+
+  TableFlattenerOptions options;
+  options.collapse_key_stringpool = true;
+
+  ResTable res_table;
+  EXPECT_THAT(Flatten(context_.get(), options, table.get(), &res_table), testing::IsTrue());
+  EXPECT_THAT(Exists(&res_table, "com.app.test:color/overlayable_color", ResourceId(0x7f010000), {},
+                     Res_value::TYPE_INT_COLOR_ARGB8, 0xffaabbcc, 0u),
+              testing::IsTrue());
+}
+
+TEST_F(TableFlattenerTest, FlattenTypeEntryWithNameCollapseInExemption) {
+  OverlayableItem overlayable_item(std::make_shared<Overlayable>("TestName", "overlay://theme"));
+  overlayable_item.policies |= PolicyFlags::PUBLIC;
+
+  std::string name = "com.app.test:color/overlayable_color";
+  std::unique_ptr<ResourceTable> table =
+      test::ResourceTableBuilder()
+          .AddValue("com.app.test:color/overlayable_color", ResourceId(0x7f010000),
+                    util::make_unique<BinaryPrimitive>(uint8_t(Res_value::TYPE_INT_COLOR_ARGB8),
+                                                       0xffaabbcc))
+          .SetOverlayable(name, overlayable_item)
+          .Build();
+
+  TableFlattenerOptions options;
+  options.collapse_key_stringpool = true;
+  options.name_collapse_exemptions.insert(
+      ResourceName({}, ResourceType::kColor, "overlayable_color"));
+
+  ResTable res_table;
+  EXPECT_THAT(Flatten(context_.get(), options, table.get(), &res_table), testing::IsTrue());
+  EXPECT_THAT(Exists(&res_table, "com.app.test:color/overlayable_color", ResourceId(0x7f010000), {},
+                     Res_value::TYPE_INT_COLOR_ARGB8, 0xffaabbcc, 0u),
+              testing::IsTrue());
+}
+
 }  // namespace aapt