// Copyright 2017 Google Inc.
//
// 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_CONFIG_H_
#define TINK_CONFIG_H_

#include <string>

#include "absl/status/status.h"
#include "absl/strings/ascii.h"
#include "tink/aead/aead_config.h"
#include "tink/catalogue.h"
#include "tink/daead/deterministic_aead_config.h"
#include "tink/hybrid/hybrid_config.h"
#include "tink/key_manager.h"
#include "tink/mac/mac_config.h"
#include "tink/registry.h"
#include "tink/signature/signature_config.h"
#include "tink/streamingaead/streaming_aead_config.h"
#include "tink/util/errors.h"
#include "tink/util/status.h"
#include "proto/config.pb.h"

namespace crypto {
namespace tink {

// Static methods for handling of Tink configurations.
//
// Configurations, i.e., collections of key types and their corresponding key
// managers supported by a specific run-time environment enable control
// of Tink setup via JSON-formatted config files that determine which key types
// are supported, and provide a mechanism for deprecation of obsolete/outdated
// cryptographic schemes (see tink/proto/config.proto for more info).
//
// Example usage:
//
// RegistryConfig registry_config = ...;
// auto status = Config::Register(registry_config);
//
class Config {
 public:
  // Returns a KeyTypeEntry for Tink key types with the specified parameters.
  static std::unique_ptr<google::crypto::tink::KeyTypeEntry>
  GetTinkKeyTypeEntry(const std::string& catalogue_name,
                      const std::string& primitive_name,
                      const std::string& key_proto_name,
                      int key_manager_version, bool new_key_allowed);

  // Registers a key manager according to the specification in 'entry'.
  template <class P>
  static crypto::tink::util::Status Register(
      const google::crypto::tink::KeyTypeEntry& entry);

  // Registers key managers and primitive wrappers according to the
  // specification in 'config'.
  static crypto::tink::util::Status Register(
      const google::crypto::tink::RegistryConfig& config);

 private:
  static crypto::tink::util::Status Validate(
      const google::crypto::tink::KeyTypeEntry& entry);
};

///////////////////////////////////////////////////////////////////////////////
// Implementation details of templated methods.

// static
template <class P>
crypto::tink::util::Status Config::Register(
    const google::crypto::tink::KeyTypeEntry& entry) {
  util::Status status;
  std::string primitive_name = absl::AsciiStrToLower(entry.primitive_name());

  if (primitive_name == "mac") {
    status = MacConfig::Register();
  } else if (primitive_name == "aead") {
    status = AeadConfig::Register();
  } else if (primitive_name == "deterministicaead") {
    status = DeterministicAeadConfig::Register();
  } else if (primitive_name == "hybridencrypt" ||
             primitive_name == "hybriddecrypt") {
    status = HybridConfig::Register();
  } else if (primitive_name == "publickeysign" ||
             primitive_name == "publickeyverify") {
    status = SignatureConfig::Register();
  } else if (primitive_name == "streamingaead") {
    status = StreamingAeadConfig::Register();
  } else {
    status = util::Status(
        absl::StatusCode::kInvalidArgument,
        absl::StrCat("Non-standard primitive '", entry.primitive_name(),
                     "', call Registry::RegisterKeyManager "
                     "and Registry::"
                     "RegisterPrimitiveWrapper directly."));
  }
  if (!status.ok()) return status;
  return util::OkStatus();
}

}  // namespace tink
}  // namespace crypto

#endif  // TINK_CONFIG_H_