blob: 57434341a2c5684982d23afe94eeb5129c0a6ac3 [file] [log] [blame]
// Copyright 2016 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
// A fuzzer that checks correctness of json parser/writer.
// The fuzzer input is passed through parsing twice,
// so that presumably valid json is parsed/written again.
#include <stddef.h>
#include <stdint.h>
#include <string>
#include "base/json/json_reader.h"
#include "base/json/json_writer.h"
#include "base/json/string_escape.h"
#include "base/logging.h"
#include "base/values.h"
// Entry point for libFuzzer.
// We will use the last byte of data as parsing options.
// The rest will be used as text input to the parser.
extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
if (size < 2)
return 0;
int error_code, error_line, error_column;
std::string error_message;
const std::string input_string(reinterpret_cast<const char*>(data), size - 1);
const int options = data[size - 1];
auto parsed_value = base::JSONReader::ReadAndReturnError(
input_string, options, &error_code, &error_message, &error_line,
if (!parsed_value)
return 0;
std::string parsed_output;
bool b = base::JSONWriter::Write(*parsed_value, &parsed_output);
auto double_parsed_value = base::JSONReader::ReadAndReturnError(
parsed_output, options, &error_code, &error_message, &error_line,
std::string double_parsed_output;
bool b2 =
base::JSONWriter::Write(*double_parsed_value, &double_parsed_output);
LOG_ASSERT(parsed_output == double_parsed_output)
<< "Parser/Writer mismatch."
<< "\nInput=" << base::GetQuotedJSONString(parsed_output)
<< "\nOutput=" << base::GetQuotedJSONString(double_parsed_output);
return 0;