Merge "Fix brotli decompressor interface usage when reading past the end."

Android.bp

@@ -113,6 +113,7 @@ cc_test {
     test_suites: ["device-tests"],
     srcs: [
         "brotli_compressor_unittest.cc",
+        "brotli_decompressor_unittest.cc",
         "bsdiff_arguments.cc",
         "bsdiff_arguments_unittest.cc",
         "bsdiff_unittest.cc",

Makefile

@@ -64,6 +64,7 @@ bspatch_src_files := \
 # Unit test files.
 bsdiff_common_unittests := \
     brotli_compressor_unittest.cc \
+    brotli_decompressor_unittest.cc \
     bsdiff_arguments.cc \
     bsdiff_arguments_unittest.cc \
     bsdiff_unittest.cc \

brotli_decompressor.cc

@@ -48,6 +48,18 @@ bool BrotliDecompressor::Read(uint8_t* output_data, size_t bytes_to_output) {
     } else if (result == BROTLI_DECODER_RESULT_NEEDS_MORE_INPUT) {
       LOG(ERROR) << "Decompressor reached EOF while reading from input stream.";
       return false;
+    } else if (result == BROTLI_DECODER_RESULT_SUCCESS) {
+      // This means that decoding is finished, no more input might be consumed
+      // and no more output will be produced. In the normal case, when there is
+      // more data available than what was requested in this Read() call it
+      // returns BROTLI_DECODER_RESULT_NEEDS_MORE_OUTPUT.
+      if (available_out > 0) {
+        LOG(ERROR) << "Expected to read " << available_out
+                   << " more bytes but reached the end of compressed brotli "
+                      "stream";
+        return false;
+      }
+      return true;
     }
   }
   return true;

brotli_decompressor_unittest.cc

@@ -0,0 +1,66 @@
+// Copyright 2018 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "bsdiff/brotli_decompressor.h"
+
+#include <memory>
+#include <string>
+#include <vector>
+
+#include <gtest/gtest.h>
+
+namespace {
+
+// echo -n "Hello!" | brotli -9 | hexdump -v -e '"    " 11/1 "0x%02x, " "\n"'
+constexpr uint8_t kBrotliHello[] = {
+    0x8b, 0x02, 0x80, 0x48, 0x65, 0x6c, 0x6c, 0x6f, 0x21, 0x03,
+};
+
+}  // namespace
+
+namespace bsdiff {
+
+class BrotliDecompressorTest : public testing::Test {
+ protected:
+  void SetUp() {
+    decompressor_.reset(new BrotliDecompressor());
+    EXPECT_NE(nullptr, decompressor_.get());
+  }
+
+  std::unique_ptr<BrotliDecompressor> decompressor_;
+};
+
+TEST_F(BrotliDecompressorTest, SmokeTest) {
+  EXPECT_TRUE(decompressor_->SetInputData(kBrotliHello, sizeof(kBrotliHello)));
+  std::vector<uint8_t> output_data(6);
+  EXPECT_TRUE(decompressor_->Read(output_data.data(), output_data.size()));
+  std::string hello = "Hello!";
+  EXPECT_EQ(std::vector<uint8_t>(hello.begin(), hello.end()), output_data);
+}
+
+TEST_F(BrotliDecompressorTest, ReadingFromEmptyFileTest) {
+  uint8_t data = 0;
+  EXPECT_TRUE(decompressor_->SetInputData(&data, 0));
+
+  uint8_t output_data[10];
+  EXPECT_FALSE(decompressor_->Read(output_data, sizeof(output_data)));
+}
+
+// Check that we fail to read from a truncated file.
+TEST_F(BrotliDecompressorTest, ReadingFromTruncatedFileTest) {
+  // We feed only half of the compressed file.
+  EXPECT_TRUE(
+      decompressor_->SetInputData(kBrotliHello, sizeof(kBrotliHello) / 2));
+  uint8_t output_data[6];
+  EXPECT_FALSE(decompressor_->Read(output_data, sizeof(output_data)));
+}
+
+// Check that we fail to read more than it is available in the file.
+TEST_F(BrotliDecompressorTest, ReadingMoreThanAvailableTest) {
+  EXPECT_TRUE(decompressor_->SetInputData(kBrotliHello, sizeof(kBrotliHello)));
+  uint8_t output_data[1000];
+  EXPECT_FALSE(decompressor_->Read(output_data, sizeof(output_data)));
+}
+
+}  // namespace bsdiff

bsdiff.gyp

@@ -151,6 +151,7 @@
           'includes': ['../common-mk/common_test.gypi'],
           'sources': [
             'brotli_compressor_unittest.cc',
+            'brotli_decompressor_unittest.cc',
             'bsdiff_arguments.cc',
             'bsdiff_arguments_unittest.cc',
             'bsdiff_unittest.cc',