text: // 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.
  //
  ///////////////////////////////////////////////////////////////////////////////
  
  #include <algorithm>
  #include <vector>
  
  #ifndef TINK_AEAD_AES_CTR_HMAC_AEAD_KEY_MANAGER_H_
  #define TINK_AEAD_AES_CTR_HMAC_AEAD_KEY_MANAGER_H_
  
  #include "absl/strings/string_view.h"
  #include "tink/aead.h"
  #include "tink/key_manager.h"
  #include "tink/util/errors.h"
  #include "tink/util/protobuf_helper.h"
  #include "tink/util/status.h"
  #include "tink/util/statusor.h"
  #include "proto/aes_ctr_hmac_aead.pb.h"
  #include "proto/tink.pb.h"
  
  namespace crypto {
  namespace tink {
  
  class AesCtrHmacAeadKeyManager : public KeyManager<Aead> {
   public:
    static constexpr char kKeyType[] =
        "type.googleapis.com/google.crypto.tink.AesCtrHmacAeadKey";
    static constexpr char kHmacKeyType[] =
        "type.googleapis.com/google.crypto.tink.HmacKey";
    static constexpr uint32_t kVersion = 0;
  
    AesCtrHmacAeadKeyManager();
  
    // Constructs an instance of AES-CTR-HMAC-AEAD Aead for the given 'key_data',
    // which must contain AesCtrHmacAeadKey-proto.
    crypto::tink::util::StatusOr<std::unique_ptr<Aead>> GetPrimitive(
        const google::crypto::tink::KeyData& key_data) const override;
  
    // Constructs an instance of AES-CTR-HMAC-AEAD Aead for the given 'key',
    // which must be AesCtrHmacAeadKey-proto.
    crypto::tink::util::StatusOr<std::unique_ptr<Aead>> GetPrimitive(
        const portable_proto::MessageLite& key) const override;
  
    // Returns the type_url identifying the key type handled by this manager.
    const std::string& get_key_type() const override;
  
    // Returns the version of this key manager.
    uint32_t get_version() const override;
  
    // Returns a factory that generates keys of the key type
    // handled by this manager.
    const KeyFactory& get_key_factory() const override;
  
    virtual ~AesCtrHmacAeadKeyManager() {}
  
   private:
    friend class AesCtrHmacAeadKeyFactory;
  
    static constexpr char kKeyTypePrefix[] = "type.googleapis.com/";
    static constexpr char kKeyFormatUrl[] =
        "type.googleapis.com/google.crypto.tink.AesCtrHmacAeadKeyFormat";
  
    std::string key_type_;
    std::unique_ptr<KeyFactory> key_factory_;
  
    // Constructs an instance of AES-CTR-HMAC-AEAD Aead for the given 'key'.
    crypto::tink::util::StatusOr<std::unique_ptr<Aead>> GetPrimitiveImpl(
        const google::crypto::tink::AesCtrHmacAeadKey& key) const;
  
    static crypto::tink::util::Status Validate(
        const google::crypto::tink::AesCtrHmacAeadKey& key);
    static crypto::tink::util::Status Validate(
        const google::crypto::tink::AesCtrHmacAeadKeyFormat& key_format);
  };
  
  }  // namespace tink
  }  // namespace crypto
  
  #endif  // TINK_AEAD_AES_CTR_HMAC_AEAD_KEY_MANAGER_H_
  