// Copyright 1995-2016 The OpenSSL Project 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

//

//     https://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 <stddef.h>

#include <openssl/cipher.h>

#include <openssl/des.h>

#include <openssl/nid.h>

#include "../des/internal.h"

#include "../fipsmodule/cipher/internal.h"

#include "internal.h"

using namespace bssl;

typedef struct {

  union {

    double align;

    DES_key_schedule ks;

  } ks;

} EVP_DES_KEY;

static int des_init_key(EVP_CIPHER_CTX *ctx, const uint8_t *key,

                        const uint8_t *iv, int enc) {

  EVP_DES_KEY *dat = (EVP_DES_KEY *)ctx->cipher_data;

  DES_set_key_ex(key, &dat->ks.ks);

  return 1;

}

static int des_cbc_cipher_update(EVP_CIPHER_CTX *ctx, uint8_t *out,

                                 const uint8_t *in, size_t len) {

  EVP_DES_KEY *dat = (EVP_DES_KEY *)ctx->cipher_data;

  DES_ncbc_encrypt_ex(in, out, len, &dat->ks.ks, ctx->iv, ctx->encrypt);

  return 1;

}

static const EVP_CIPHER evp_des_cbc = {

    /*nid=*/NID_des_cbc,

    /*block_size=*/8,

    /*key_len=*/8,

    /*iv_len=*/8,

    /*ctx_size=*/sizeof(EVP_DES_KEY),

    /*flags=*/EVP_CIPH_CBC_MODE,

    /*init=*/des_init_key,

    /*cipher_update=*/des_cbc_cipher_update,

    /*cipher_final=*/nullptr,

    /*update_aad=*/nullptr,

    /*cleanup=*/nullptr,

    /*ctrl=*/nullptr,

};

const EVP_CIPHER *EVP_des_cbc() { return &evp_des_cbc; }

static int des_ecb_cipher_update(EVP_CIPHER_CTX *ctx, uint8_t *out,

                                 const uint8_t *in, size_t len) {

  if (len < ctx->cipher->block_size) {

    return 1;

  }

  len -= ctx->cipher->block_size;

  EVP_DES_KEY *dat = (EVP_DES_KEY *)ctx->cipher_data;

  for (size_t i = 0; i <= len; i += ctx->cipher->block_size) {

    DES_ecb_encrypt_ex(in + i, out + i, &dat->ks.ks, ctx->encrypt);

  }

  return 1;

}

static const EVP_CIPHER evp_des_ecb = {

    /*nid=*/NID_des_ecb,

    /*block_size=*/8,

    /*key_len=*/8,

    /*iv_len=*/0,

    /*ctx_size=*/sizeof(EVP_DES_KEY),

    /*flags=*/EVP_CIPH_ECB_MODE,

    /*init=*/des_init_key,

    /*cipher_update=*/des_ecb_cipher_update,

    /*cipher_final=*/nullptr,

    /*update_aad=*/nullptr,

    /*cleanup=*/nullptr,

    /*ctrl=*/nullptr,

};

const EVP_CIPHER *EVP_des_ecb() { return &evp_des_ecb; }

typedef struct {

  union {

    double align;

    DES_key_schedule ks[3];

  } ks;

} DES_EDE_KEY;

static int des_ede3_init_key(EVP_CIPHER_CTX *ctx, const uint8_t *key,

                             const uint8_t *iv, int enc) {

  DES_EDE_KEY *dat = (DES_EDE_KEY *)ctx->cipher_data;

  DES_set_key_ex(key, &dat->ks.ks[0]);

  DES_set_key_ex(key + 8, &dat->ks.ks[1]);

  DES_set_key_ex(key + 16, &dat->ks.ks[2]);

  return 1;

}

static int des_ede3_cbc_cipher_update(EVP_CIPHER_CTX *ctx, uint8_t *out,

                                      const uint8_t *in, size_t len) {

  DES_EDE_KEY *dat = (DES_EDE_KEY *)ctx->cipher_data;

  DES_ede3_cbc_encrypt_ex(in, out, len, &dat->ks.ks[0], &dat->ks.ks[1],

                          &dat->ks.ks[2], ctx->iv, ctx->encrypt);

  return 1;

}

static const EVP_CIPHER evp_des_ede3_cbc = {

    /*nid=*/NID_des_ede3_cbc,

    /*block_size=*/8,

    /*key_len=*/24,

    /*iv_len=*/8,

    /*ctx_size=*/sizeof(DES_EDE_KEY),

    /*flags=*/EVP_CIPH_CBC_MODE,

    /*init=*/des_ede3_init_key,

    /*cipher_update=*/des_ede3_cbc_cipher_update,

    /*cipher_final=*/nullptr,

    /*update_aad=*/nullptr,

    /*cleanup=*/nullptr,

    /*ctrl=*/nullptr,

};

const EVP_CIPHER *EVP_des_ede3_cbc() { return &evp_des_ede3_cbc; }

static int des_ede_init_key(EVP_CIPHER_CTX *ctx, const uint8_t *key,

                            const uint8_t *iv, int enc) {

  DES_EDE_KEY *dat = (DES_EDE_KEY *)ctx->cipher_data;

  // 2-DES is 3-DES with the first key used twice.

  DES_set_key_ex(key, &dat->ks.ks[0]);

  DES_set_key_ex(key + 8, &dat->ks.ks[1]);

  DES_set_key_ex(key, &dat->ks.ks[2]);

  return 1;

}

static const EVP_CIPHER evp_des_ede_cbc = {

    /*nid=*/NID_des_ede_cbc,

    /*block_size=*/8,

    /*key_len=*/16,

    /*iv_len=*/8,

    /*ctx_size=*/sizeof(DES_EDE_KEY),

    /*flags=*/EVP_CIPH_CBC_MODE,

    /*init=*/des_ede_init_key,

    /*cipher_update=*/des_ede3_cbc_cipher_update,

    /*cipher_final=*/nullptr,

    /*update_aad=*/nullptr,

    /*cleanup=*/nullptr,

    /*ctrl=*/nullptr,

};

const EVP_CIPHER *EVP_des_ede_cbc() { return &evp_des_ede_cbc; }

static int des_ede_ecb_cipher_update(EVP_CIPHER_CTX *ctx, uint8_t *out,

                                     const uint8_t *in, size_t len) {

  if (len < ctx->cipher->block_size) {

    return 1;

  }

  len -= ctx->cipher->block_size;

  DES_EDE_KEY *dat = (DES_EDE_KEY *)ctx->cipher_data;

  for (size_t i = 0; i <= len; i += ctx->cipher->block_size) {

    DES_ecb3_encrypt_ex(in + i, out + i, &dat->ks.ks[0], &dat->ks.ks[1],

                        &dat->ks.ks[2], ctx->encrypt);

  }

  return 1;

}

static const EVP_CIPHER evp_des_ede = {

    /*nid=*/NID_des_ede_ecb,

    /*block_size=*/8,

    /*key_len=*/16,

    /*iv_len=*/0,

    /*ctx_size=*/sizeof(DES_EDE_KEY),

    /*flags=*/EVP_CIPH_ECB_MODE,

    /*init=*/des_ede_init_key,

    /*cipher_update=*/des_ede_ecb_cipher_update,

    /*cipher_final=*/nullptr,

    /*update_aad=*/nullptr,

    /*cleanup=*/nullptr,

    /*ctrl=*/nullptr,

};

const EVP_CIPHER *EVP_des_ede() { return &evp_des_ede; }

static const EVP_CIPHER evp_des_ede3 = {

    /*nid=*/NID_des_ede3_ecb,

    /*block_size=*/8,

    /*key_len=*/24,

    /*iv_len=*/0,

    /*ctx_size=*/sizeof(DES_EDE_KEY),

    /*flags=*/EVP_CIPH_ECB_MODE,

    /*init=*/des_ede3_init_key,

    /*cipher_update=*/des_ede_ecb_cipher_update,

    /*cipher_final=*/nullptr,

    /*update_aad=*/nullptr,

    /*cleanup=*/nullptr,

    /*ctrl=*/nullptr,

};

const EVP_CIPHER *EVP_des_ede3() { return &evp_des_ede3; }

const EVP_CIPHER *EVP_des_ede3_ecb() { return EVP_des_ede3(); }