Merge "Added flac_extractor_fuzzer"

        "libbinder",

    ],

}

cc_fuzz {

    name: "flac_extractor_fuzzer",

    srcs: [

        "flac_extractor_fuzzer.cpp",

    ],

    include_dirs: [

        "frameworks/av/media/extractors/flac",

    ],

    static_libs: [

        "liblog",

        "libstagefright_foundation",

        "libmedia",

        "libextractorfuzzerbase",

        "libstagefright_metadatautils",

        "libFLAC",

        "libflacextractor",

    ],

    shared_libs: [

        "libutils",

        "libmediandk",

        "libbinder",

        "libbinder_ndk",

        "libbase",

    ],

    dictionary: "flac_extractor_fuzzer.dict",

}

+ [libwavextractor](#wavExtractorFuzzer)

+ [libmp3extractor](#mp3ExtractorFuzzer)

+ [libaacextractor](#aacExtractorFuzzer)

+ [libflacextractor](#flacExtractor)

# <a name="ExtractorFuzzerBase"></a> Fuzzer for libextractorfuzzerbase

All the extractors have a common API - creating a data source, extraction

  $ adb shell /data/fuzz/arm64/aac_extractor_fuzzer/aac_extractor_fuzzer CORPUS_DIR

```

# <a name="flacExtractor"></a> Fuzzer for libflacextractor

## Plugin Design Considerations

The fuzzer plugin for FLAC extractor uses the `ExtractorFuzzerBase` class and

implements only the `createExtractor` to create the FLAC extractor object.

##### Maximize code coverage

Dict file (dictionary file) is created for FLAC to ensure that the required start

bytes are present in every input file that goes to the fuzzer.

This ensures that larger code gets covered.

## Build

This describes steps to build flac_extractor_fuzzer binary.

### Android

#### Steps to build

Build the fuzzer

```

  $ mm -j$(nproc) flac_extractor_fuzzer

```

#### Steps to run

Create a directory CORPUS_DIR and copy some flac files to that folder

Push this directory to device.

To run on device

```

  $ adb sync data

  $ adb shell /data/fuzz/arm64/flac_extractor_fuzzer/flac_extractor_fuzzer CORPUS_DIR

```

## References:

 * http://llvm.org/docs/LibFuzzer.html

 * https://github.com/google/oss-fuzz

/******************************************************************************

 *

 * Copyright (C) 2020 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.

 *

 *****************************************************************************

 * Originally developed and contributed by Ittiam Systems Pvt. Ltd, Bangalore

 */

#include "ExtractorFuzzerBase.h"

#include "FLACExtractor.h"

using namespace android;

class FlacExtractor : public ExtractorFuzzerBase {

 public:

  FlacExtractor() = default;

  ~FlacExtractor() = default;

  bool createExtractor();

};

bool FlacExtractor::createExtractor() {

  mExtractor = new FLACExtractor(new DataSourceHelper(mDataSource->wrap()));

  if (!mExtractor) {

    return false;

  }

  mExtractor->name();

  return true;

}

extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {

  if ((!data) || (size == 0)) {

    return 0;

  }

  FlacExtractor* extractor = new FlacExtractor();

  if (!extractor) {

    return 0;

  }

  if (extractor->setDataSource(data, size)) {

    if (extractor->createExtractor()) {

      extractor->getExtractorDef();

      extractor->getMetadata();

      extractor->extractTracks();

      extractor->getTracksMetadata();

    }

  }

  delete extractor;

  return 0;

}

# Start code (bytes 0-3)

# The below 4 bytes correspond to "fLaC" in ASCII

kw1="\x66\x4C\x61\x43"