services/data_decoder/public/cpp/json_sanitizer.h

// Copyright 2019 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef SERVICES_DATA_DECODER_PUBLIC_CPP_JSON_SANITIZER_H_
#define SERVICES_DATA_DECODER_PUBLIC_CPP_JSON_SANITIZER_H_

#include <string>

#include "base/functional/callback.h"
#include "base/types/expected.h"

namespace data_decoder {

// Sanitizes and normalizes JSON by parsing it in a safe environment and
// re-serializing it. Parsing the sanitized JSON should result in a value
// identical to parsing the original JSON.
//
// This allows parsing the sanitized JSON with the regular JSONParser while
// reducing the risk versus parsing completely untrusted JSON. It also minifies
// the resulting JSON, which might save some space.
class JsonSanitizer {
 public:
  using Result = base::expected<std::string, std::string>;
  using Callback = base::OnceCallback<void(Result)>;

  JsonSanitizer(const JsonSanitizer&) = delete;
  JsonSanitizer& operator=(const JsonSanitizer&) = delete;

  // Starts sanitizing the passed in unsafe JSON string. The passed |callback|
  // will be called with the result of the sanitization or an error message, but
  // not before the method returns.
  static void Sanitize(const std::string& json, Callback callback);
};

}  // namespace data_decoder

#endif  // SERVICES_DATA_DECODER_PUBLIC_CPP_JSON_SANITIZER_H_