/*

 * Copyright (C) 2011-2012 Free Software Foundation, Inc.

 * Copyright (C) 2018 Red Hat, Inc.

 *

 * Author: Nikos Mavrogiannopoulos

 *

 * This file is part of GnuTLS.

 *

 * The GnuTLS is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public License

 * as published by the Free Software Foundation; either version 2.1 of

 * the License, or (at your option) any later version.

 *

 * This library is distributed in the hope that it will be useful, but

 * WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public License

 * along with this program.  If not, see <https://www.gnu.org/licenses/>

 *

 */

/*

 * The following code is an implementation of the AES-128-CBC cipher

 * using intel's AES instruction set. 

 */

#include "errors.h"

#include "gnutls_int.h"

#include <gnutls/crypto.h>

#include "errors.h"

#include <aes-x86.h>

#include <sha-x86.h>

#include <x86-common.h>

struct aes_ctx {

  AES_KEY expanded_key;

  uint8_t iv[16];

  int enc;

};

static int

aes_cipher_init(gnutls_cipher_algorithm_t algorithm, void **_ctx, int enc)

{

  /* we use key size to distinguish */

  if (algorithm != GNUTLS_CIPHER_AES_128_CBC

      && algorithm != GNUTLS_CIPHER_AES_192_CBC

      && algorithm != GNUTLS_CIPHER_AES_256_CBC)

    return GNUTLS_E_INVALID_REQUEST;

  *_ctx = gnutls_calloc(1, sizeof(struct aes_ctx));

  if (*_ctx == NULL) {

    gnutls_assert();

    return GNUTLS_E_MEMORY_ERROR;

  }

  ((struct aes_ctx *)(*_ctx))->enc = enc;

  return 0;

}

static int aes_cipher_setkey(void *_ctx, const void *userkey, size_t keysize)

{

  struct aes_ctx *ctx = _ctx;

  int ret;

  CHECK_AES_KEYSIZE(keysize);

  if (ctx->enc)

    ret =

        aesni_set_encrypt_key(userkey, keysize * 8,

            ALIGN16(&ctx->expanded_key));

  else

    ret =

        aesni_set_decrypt_key(userkey, keysize * 8,

            ALIGN16(&ctx->expanded_key));

  if (ret != 0)

    return gnutls_assert_val(GNUTLS_E_ENCRYPTION_FAILED);

  return 0;

}

static int aes_setiv(void *_ctx, const void *iv, size_t iv_size)

{

  struct aes_ctx *ctx = _ctx;

  if (iv_size != 16)

    return gnutls_assert_val(GNUTLS_E_INVALID_REQUEST);

  memcpy(ctx->iv, iv, 16);

  return 0;

}

static int

aes_encrypt(void *_ctx, const void *src, size_t src_size,

      void *dst, size_t dst_size)

{

  struct aes_ctx *ctx = _ctx;

  if (unlikely(dst_size < src_size))

    return gnutls_assert_val(GNUTLS_E_SHORT_MEMORY_BUFFER);

  if (unlikely(src_size % 16 != 0))

    return gnutls_assert_val(GNUTLS_E_INVALID_REQUEST);

  aesni_cbc_encrypt(src, dst, src_size, ALIGN16(&ctx->expanded_key),

        ctx->iv, 1);

  return 0;

}

static int

aes_decrypt(void *_ctx, const void *src, size_t src_size,

      void *dst, size_t dst_size)

{

  struct aes_ctx *ctx = _ctx;

  if (unlikely(dst_size < src_size))

    return gnutls_assert_val(GNUTLS_E_SHORT_MEMORY_BUFFER);

  if (unlikely(src_size % 16 != 0))

    return gnutls_assert_val(GNUTLS_E_INVALID_REQUEST);

  aesni_cbc_encrypt(src, dst, src_size, ALIGN16(&ctx->expanded_key),

        ctx->iv, 0);

  return 0;

}

static void aes_deinit(void *_ctx)

{

  struct aes_ctx *ctx = _ctx;

  zeroize_temp_key(ctx, sizeof(*ctx));

  gnutls_free(ctx);

}

const gnutls_crypto_cipher_st _gnutls_aesni_x86 = {

  .init = aes_cipher_init,

  .setkey = aes_cipher_setkey,

  .setiv = aes_setiv,

  .encrypt = aes_encrypt,

  .decrypt = aes_decrypt,

  .deinit = aes_deinit,

};