// Copyright (c) 2021 PaddlePaddle Authors. All Rights Reserved.
//
// 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.
#pragma once

#ifndef PADDLE_MODEL_PROTECT_UTIL_CRYPTO_AES_GCM_H
#define PADDLE_MODEL_PROTECT_UTIL_CRYPTO_AES_GCM_H

#include <openssl/aes.h>
#include <openssl/evp.h>
#include <iostream>
#include <string>

#include "fastdeploy/encryption/util/include/crypto/basic.h"

namespace fastdeploy {
namespace util {
namespace crypto {
// aes key 32 byte for 256 bit
#define AES_GCM_KEY_LENGTH 32

// aes tag 16 byte for 128 bit
#define AES_GCM_TAG_LENGTH 16

// aes iv 12 byte for 96 bit
#define AES_GCM_IV_LENGTH 16

class AesGcm {
 public:
  /**
   * \brief        initial aes-gcm-256 context use key & iv
   *
   * \note         initial aes-gcm-256 context use key & iv. gcm mode
   *               will generate a tag(16 byte), so the ciphertext's length
   *               should be longer 16 byte than plaintext.
   *
   *
   * \param plaintext     plain text to be encrypted(in)
   * \param len      plain text's length(in)
   * \param key     aes key (in)
   * \param iv      aes iv (in)
   * \param ciphertext   encrypted text(out)
   * \param out_len   encrypted length(out)
   *
   * \return         return  0 if successful
   *                        -1 EVP_CIPHER_CTX_new or aes_gcm_key error
   *                        -2 EVP_EncryptUpdate error
   *                        -3 EVP_EncryptFinal_ex error
   *                        -4 EVP_CIPHER_CTX_ctrl error
   */
  static int encrypt_aes_gcm(const unsigned char* plaintext, const int& len,
                             const unsigned char* key, const unsigned char* iv,
                             unsigned char* ciphertext,
                             int& out_len);  // NOLINT
  /**
   * \brief        encrypt using aes-gcm-256
   *
   * \note         encrypt using aes-gcm-256
   *
   * \param ciphertext     cipher text to be decrypted(in)
   * \param len      plain text's length(in)
   * \param key     aes key (in)
   * \param iv      aes iv (in)
   * \param plaintext   decrypted text(out)
   * \param out_len   decrypted length(out)
   *
   * \return         return  0 if successful
   *                        -1 EVP_CIPHER_CTX_new or aes_gcm_key error
   *                        -2 EVP_DecryptUpdate error
   *                        -3 EVP_CIPHER_CTX_ctrl error
   *                        -4 EVP_DecryptFinal_ex error
   */
  static int decrypt_aes_gcm(const unsigned char* ciphertext, const int& len,
                             const unsigned char* key, const unsigned char* iv,
                             unsigned char* plaintext, int& out_len);  // NOLINT

 private:
  /**
   * \brief        initial aes-gcm-256 context use key & iv
   *
   * \note         initial aes-gcm-256 context use key & iv
   *
   * \param key     aes key (in)
   * \param iv      aes iv (in)
   * \param e_ctx   encryption context(out)
   * \param d_ctx   decryption context(out)
   *
   * \return         return  0 if successful
   *                        -1 EVP_xxcryptInit_ex error
   *                        -2 EVP_CIPHER_CTX_ctrl error
   *                        -3 EVP_xxcryptInit_ex error
   */
  static int aes_gcm_key(const unsigned char* key, const unsigned char* iv,
                         EVP_CIPHER_CTX* e_ctx, EVP_CIPHER_CTX* d_ctx);

  /**
   * \brief        initial aes-gcm-256 context use key & iv
   *
   * \note         initial aes-gcm-256 context use key & iv
   *
   * \param key     aes key (in)
   * \param iv      aes iv (in)
   * \param e_ctx   encryption context(out)
   * \param d_ctx   decryption context(out)
   *
   * \return         return  0 if successful
   *                        -1 EVP_xxcryptInit_ex error
   *                        -2 EVP_CIPHER_CTX_ctrl error
   *                        -3 EVP_xxcryptInit_ex error
   *                        -4 invalid key length or iv length
   *                        -5 hex_to_byte error
   */
  static int aes_gcm_key(const std::string& key_hex, const std::string& iv_hex,
                         EVP_CIPHER_CTX* e_ctx, EVP_CIPHER_CTX* d_ctx);
};

}  // namespace crypto
}  // namespace util
}  // namespace fastdeploy
#endif  // PADDLE_MODEL_PROTECT_UTIL_CRYPTO_AES_GCM_H