tink/key_gen_configuration.h

// Copyright 2023 Google LLC
//
// 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.
//
////////////////////////////////////////////////////////////////////////////////

#ifndef TINK_KEY_GEN_CONFIGURATION_H_
#define TINK_KEY_GEN_CONFIGURATION_H_

#include <memory>
#include <typeindex>

#include "absl/container/flat_hash_map.h"
#include "absl/functional/any_invocable.h"
#include "absl/status/statusor.h"
#include "absl/types/optional.h"
#include "tink/internal/key_type_info_store.h"
#include "tink/key.h"
#include "tink/parameters.h"

namespace crypto {
namespace tink {

namespace internal {
template <class P>
using KeyCreatorFn = absl::AnyInvocable<absl::StatusOr<std::unique_ptr<Key>>(
    const P&, absl::optional<int>) const>;
using KeyCreatorFnMap =
    absl::flat_hash_map<std::type_index, KeyCreatorFn<Parameters>>;

class KeyGenConfigurationImpl;
}  // namespace internal

// KeyGenConfiguration used to generate keys using stored key type managers.
class KeyGenConfiguration {
 public:
  KeyGenConfiguration() = default;

  // Not copyable or movable.
  KeyGenConfiguration(const KeyGenConfiguration&) = delete;
  KeyGenConfiguration& operator=(const KeyGenConfiguration&) = delete;

 private:
  friend class internal::KeyGenConfigurationImpl;

  // When true, KeyGenConfiguration is in global registry mode. For
  // `some_fn(config)` with a `config` parameter, this indicates to `some_fn` to
  // use crypto::tink::Registry directly.
  bool global_registry_mode_ = false;

  // KeyTypeInfoStore holds KeyTypeManagers.
  crypto::tink::internal::KeyTypeInfoStore key_type_info_store_;
  // KeyCreatorFnMap holds functions that construct a Key from Parameters.
  crypto::tink::internal::KeyCreatorFnMap key_creator_fn_map_;
};

}  // namespace tink
}  // namespace crypto

#endif  // TINK_KEY_GEN_CONFIGURATION_H_