Function TEST_F

launcher/fuzzed_data_provider_test.cpp:57–100

constexpr uint32_t kValidModifiedUtf8Seed = 0x12345678;

TEST_F(FuzzedDataProviderTest, InvalidModifiedUtf8AfterFixup) {
  auto& env = jvm_->GetEnv();
  auto modified_utf8_validator = env.FindClass("test/ModifiedUtf8Encoder");
  ASSERT_NE(nullptr, modified_utf8_validator);
  auto string_to_modified_utf_bytes = env.GetStaticMethodID(
      modified_utf8_validator, "encode", "(Ljava/lang/String;)[B");
  ASSERT_NE(nullptr, string_to_modified_utf_bytes);
  auto random_bytes = std::vector<uint8_t>(kValidModifiedUtf8NumBytes);
  auto random = std::mt19937(kValidModifiedUtf8Seed);
  for (bool ascii_only : {false, true}) {
    for (bool stop_on_backslash : {false, true}) {
      for (std::size_t i = 0; i < kValidModifiedUtf8NumRuns; ++i) {
        std::generate(random_bytes.begin(), random_bytes.end(), random);
        std::string fixed_string;
        std::tie(fixed_string, std::ignore) = FixUpModifiedUtf8(
            random_bytes.data(), random_bytes.size(),
            std::numeric_limits<jint>::max(), ascii_only, stop_on_backslash);

        jstring jni_fixed_string = env.NewStringUTF(fixed_string.c_str());
        auto jni_roundtripped_bytes = (jbyteArray)env.CallStaticObjectMethod(
            modified_utf8_validator, string_to_modified_utf_bytes,
            jni_fixed_string);
        ASSERT_FALSE(env.ExceptionCheck());
        env.DeleteLocalRef(jni_fixed_string);
        jint roundtripped_bytes_length =
            env.GetArrayLength(jni_roundtripped_bytes);
        jbyte* roundtripped_bytes =
            env.GetByteArrayElements(jni_roundtripped_bytes, nullptr);
        auto roundtripped_string =
            std::string(reinterpret_cast<char*>(roundtripped_bytes),
                        roundtripped_bytes_length);
        env.ReleaseByteArrayElements(jni_roundtripped_bytes, roundtripped_bytes,
                                     JNI_ABORT);
        env.DeleteLocalRef(jni_roundtripped_bytes);

        // Verify that the bytes obtained from running our modified UTF-8 fix-up
        // function remain unchanged when turned into a Java string and
        // reencoded into modified UTF-8. This will only happen if the our
        // fix-up function indeed returned valid modified UTF-8.
        ASSERT_EQ(fixed_string, roundtripped_string);
      }
    }
  }
}
}  // namespace jazzer