/*

 * Copyright (C) 2008-2012 Free Software Foundation, 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/>

 *

 */

#include "errors.h"

#include "gnutls_int.h"

#include <gnutls/crypto.h>

#include "crypto-backend.h"

#include "crypto.h"

#include "mpi.h"

#include "pk.h"

#include "random.h"

#include "cipher_int.h"

/* default values for priorities */

int crypto_mac_prio = INT_MAX;

int crypto_digest_prio = INT_MAX;

int crypto_cipher_prio = INT_MAX;

typedef struct algo_list {

  int algorithm;

  int priority;

  void *alg_data;

  int free_alg_data;

  struct algo_list *next;

} algo_list;

#define cipher_list algo_list

#define mac_list algo_list

#define digest_list algo_list

static int _algo_register(algo_list *al, int algorithm, int priority, void *s,

        int free_s)

{

  algo_list *cl;

  algo_list *last_cl = al;

  int ret;

  if (al == NULL) {

    ret = gnutls_assert_val(GNUTLS_E_INVALID_REQUEST);

    goto cleanup;

  }

  /* look if there is any cipher with lowest priority. In that case do not add.

   */

  cl = al;

  while (cl && cl->alg_data) {

    if (cl->algorithm == algorithm) {

      if (cl->priority < priority) {

        gnutls_assert();

        ret = GNUTLS_E_CRYPTO_ALREADY_REGISTERED;

        goto cleanup;

      } else {

        /* the current has higher priority -> overwrite */

        cl->algorithm = algorithm;

        cl->priority = priority;

        cl->alg_data = s;

        cl->free_alg_data = free_s;

        return 0;

      }

    }

    cl = cl->next;

    if (cl)

      last_cl = cl;

  }

  cl = gnutls_calloc(1, sizeof(cipher_list));

  if (cl == NULL) {

    gnutls_assert();

    ret = GNUTLS_E_MEMORY_ERROR;

    goto cleanup;

  }

  last_cl->algorithm = algorithm;

  last_cl->priority = priority;

  last_cl->alg_data = s;

  last_cl->free_alg_data = free_s;

  last_cl->next = cl;

  return 0;

cleanup:

  if (free_s)

    gnutls_free(s);

  return ret;

}

static const void *_get_algo(algo_list *al, int algo)

{

  cipher_list *cl;

  /* look if there is any cipher with lowest priority. In that case do not add.

   */

  cl = al;

  while (cl && cl->alg_data) {

    if (cl->algorithm == algo) {

      return cl->alg_data;

    }

    cl = cl->next;

  }

  return NULL;

}

static cipher_list glob_cl = { GNUTLS_CIPHER_NULL, 0, NULL, 0, NULL };

static mac_list glob_ml = { GNUTLS_MAC_NULL, 0, NULL, 0, NULL };

static digest_list glob_dl = { GNUTLS_MAC_NULL, 0, NULL, 0, NULL };

static void _deregister(algo_list *cl)

{

  algo_list *next;

  next = cl->next;

  cl->next = NULL;

  cl = next;

  while (cl) {

    next = cl->next;

    if (cl->free_alg_data)

      gnutls_free(cl->alg_data);

    gnutls_free(cl);

    cl = next;

  }

}

void _gnutls_crypto_deregister(void)

{

  _deregister(&glob_cl);

  _deregister(&glob_ml);

  _deregister(&glob_dl);

}

/*-

 * gnutls_crypto_single_cipher_register:

 * @algorithm: is the gnutls algorithm identifier

 * @priority: is the priority of the algorithm

 * @s: is a structure holding new cipher's data

 *

 * This function will register a cipher algorithm to be used by

 * gnutls.  Any algorithm registered will override the included

 * algorithms and by convention kernel implemented algorithms have

 * priority of 90 and CPU-assisted of 80.  The algorithm with the lowest priority will be

 * used by gnutls.

 *

 * In the case the registered init or setkey functions return %GNUTLS_E_NEED_FALLBACK,

 * GnuTLS will attempt to use the next in priority registered cipher.

 *

 * This function should be called before gnutls_global_init().

 *

 * For simplicity you can use the convenience

 * gnutls_crypto_single_cipher_register() macro.

 *

 * Returns: %GNUTLS_E_SUCCESS on success, otherwise a negative error code.

 *

 * Since: 2.6.0

 -*/

int gnutls_crypto_single_cipher_register(gnutls_cipher_algorithm_t algorithm,

           int priority,

           const gnutls_crypto_cipher_st *s,

           int free_s)

{

  /* we override const in case free_s is set */

  return _algo_register(&glob_cl, algorithm, priority, (void *)s, free_s);

}

const gnutls_crypto_cipher_st *

_gnutls_get_crypto_cipher(gnutls_cipher_algorithm_t algo)

{

  return _get_algo(&glob_cl, algo);

}

/**

 * gnutls_crypto_register_cipher:

 * @algorithm: is the gnutls algorithm identifier

 * @priority: is the priority of the algorithm

 * @init: A function which initializes the cipher

 * @setkey: A function which sets the key of the cipher

 * @setiv: A function which sets the nonce/IV of the cipher (non-AEAD)

 * @encrypt: A function which performs encryption (non-AEAD)

 * @decrypt: A function which performs decryption (non-AEAD)

 * @deinit: A function which deinitializes the cipher

 *

 * This function will register a cipher algorithm to be used by

 * gnutls.  Any algorithm registered will override the included

 * algorithms and by convention kernel implemented algorithms have

 * priority of 90 and CPU-assisted of 80.  The algorithm with the lowest priority will be

 * used by gnutls.

 *

 * In the case the registered init or setkey functions return %GNUTLS_E_NEED_FALLBACK,

 * GnuTLS will attempt to use the next in priority registered cipher.

 *

 * The functions which are marked as non-AEAD they are not required when

 * registering a cipher to be used with the new AEAD API introduced in

 * GnuTLS 3.4.0. Internally GnuTLS uses the new AEAD API.

 *

 * Deprecated: since 3.7.0 it is no longer possible to override cipher implementation

 *

 * Returns: %GNUTLS_E_SUCCESS on success, otherwise a negative error code.

 *

 * Since: 3.4.0

 **/

int gnutls_crypto_register_cipher(gnutls_cipher_algorithm_t algorithm,

          int priority, gnutls_cipher_init_func init,

          gnutls_cipher_setkey_func setkey,

          gnutls_cipher_setiv_func setiv,

          gnutls_cipher_encrypt_func encrypt,

          gnutls_cipher_decrypt_func decrypt,

          gnutls_cipher_deinit_func deinit)

{

  _gnutls_debug_log(

    "called the deprecated gnutls_crypto_register_cipher()\n");

  return 0;

}

int _gnutls_crypto_register_cipher(gnutls_cipher_algorithm_t algorithm,

           int priority, gnutls_cipher_init_func init,

           gnutls_cipher_setkey_func setkey,

           gnutls_cipher_setiv_func setiv,

           gnutls_cipher_encrypt_func encrypt,

           gnutls_cipher_decrypt_func decrypt,

           gnutls_cipher_deinit_func deinit)

{

  gnutls_crypto_cipher_st *s =

    gnutls_calloc(1, sizeof(gnutls_crypto_cipher_st));

  if (s == NULL)

    return gnutls_assert_val(GNUTLS_E_MEMORY_ERROR);

  s->init = init;

  s->setkey = setkey;

  s->setiv = setiv;

  s->encrypt = encrypt;

  s->decrypt = decrypt;

  s->deinit = deinit;

  return gnutls_crypto_single_cipher_register(algorithm, priority, s, 1);

}

/**

 * gnutls_crypto_register_aead_cipher:

 * @algorithm: is the gnutls AEAD cipher identifier

 * @priority: is the priority of the algorithm

 * @init: A function which initializes the cipher

 * @setkey: A function which sets the key of the cipher

 * @aead_encrypt: Perform the AEAD encryption

 * @aead_decrypt: Perform the AEAD decryption

 * @deinit: A function which deinitializes the cipher

 *

 * This function will register a cipher algorithm to be used by

 * gnutls.  Any algorithm registered will override the included

 * algorithms and by convention kernel implemented algorithms have

 * priority of 90 and CPU-assisted of 80.  The algorithm with the lowest priority will be

 * used by gnutls.

 *

 * In the case the registered init or setkey functions return %GNUTLS_E_NEED_FALLBACK,

 * GnuTLS will attempt to use the next in priority registered cipher.

 *

 * The functions registered will be used with the new AEAD API introduced in

 * GnuTLS 3.4.0. Internally GnuTLS uses the new AEAD API.

 *

 * Deprecated: since 3.7.0 it is no longer possible to override cipher implementation

 *

 * Returns: %GNUTLS_E_SUCCESS on success, otherwise a negative error code.

 *

 * Since: 3.4.0

 **/

int gnutls_crypto_register_aead_cipher(

  gnutls_cipher_algorithm_t algorithm, int priority,

  gnutls_cipher_init_func init, gnutls_cipher_setkey_func setkey,

  gnutls_cipher_aead_encrypt_func aead_encrypt,

  gnutls_cipher_aead_decrypt_func aead_decrypt,

  gnutls_cipher_deinit_func deinit)

{

  _gnutls_debug_log(

    "called the deprecated gnutls_crypto_register_aead_cipher()\n");

  return 0;

}

/*-

 * gnutls_crypto_rnd_register:

 * @priority: is the priority of the generator

 * @s: is a structure holding new generator's data

 *

 * This function will register a random generator to be used by

 * gnutls.  Any generator registered will override the included

 * generator and by convention kernel implemented generators have

 * priority of 90 and CPU-assisted of 80. The generator with the lowest priority will be

 * used by gnutls.

 *

 * This function should be called before gnutls_global_init().

 *

 * For simplicity you can use the convenience

 * gnutls_crypto_rnd_register() macro.

 *

 * Returns: %GNUTLS_E_SUCCESS on success, otherwise a negative error code.

 *

 * Since: 2.6.0

 -*/

int gnutls_crypto_rnd_register(int priority, const gnutls_crypto_rnd_st *s)

{

  if (crypto_rnd_prio >= priority) {

    memcpy(&_gnutls_rnd_ops, s, sizeof(*s));

    crypto_rnd_prio = priority;

    return 0;

  }

  return GNUTLS_E_CRYPTO_ALREADY_REGISTERED;

}

/*-

 * gnutls_crypto_single_mac_register:

 * @algorithm: is the gnutls algorithm identifier

 * @priority: is the priority of the algorithm

 * @s: is a structure holding new algorithms's data

 *

 * This function will register a MAC algorithm to be used by gnutls.

 * Any algorithm registered will override the included algorithms and

 * by convention kernel implemented algorithms have priority of 90

 *  and CPU-assisted of 80.

 * The algorithm with the lowest priority will be used by gnutls.

 *

 * This function should be called before gnutls_global_init().

 *

 * For simplicity you can use the convenience

 * gnutls_crypto_single_mac_register() macro.

 *

 * Returns: %GNUTLS_E_SUCCESS on success, otherwise a negative error code.

 *

 * Since: 2.6.0

 -*/

int gnutls_crypto_single_mac_register(gnutls_mac_algorithm_t algorithm,

              int priority,

              const gnutls_crypto_mac_st *s, int free_s)

{

  return _algo_register(&glob_ml, algorithm, priority, (void *)s, free_s);

}

const gnutls_crypto_mac_st *_gnutls_get_crypto_mac(gnutls_mac_algorithm_t algo)

{

  return _get_algo(&glob_ml, algo);

}

/*-

 * gnutls_crypto_single_digest_register:

 * @algorithm: is the gnutls algorithm identifier

 * @priority: is the priority of the algorithm

 * @s: is a structure holding new algorithms's data

 *

 * This function will register a digest (hash) algorithm to be used by

 * gnutls.  Any algorithm registered will override the included

 * algorithms and by convention kernel implemented algorithms have

 * priority of 90  and CPU-assisted of 80.  The algorithm with the lowest priority will be

 * used by gnutls.

 *

 * This function should be called before gnutls_global_init().

 *

 * For simplicity you can use the convenience

 * gnutls_crypto_single_digest_register() macro.

 *

 * Returns: %GNUTLS_E_SUCCESS on success, otherwise a negative error code.

 *

 * Since: 2.6.0

 -*/

int gnutls_crypto_single_digest_register(gnutls_digest_algorithm_t algorithm,

           int priority,

           const gnutls_crypto_digest_st *s,

           int free_s)

{

  return _algo_register(&glob_dl, algorithm, priority, (void *)s, free_s);

}

const gnutls_crypto_digest_st *

_gnutls_get_crypto_digest(gnutls_digest_algorithm_t algo)

{

  return _get_algo(&glob_dl, algo);

}

/**

 * gnutls_crypto_register_mac:

 * @algorithm: is the gnutls MAC identifier

 * @priority: is the priority of the algorithm

 * @init: A function which initializes the MAC

 * @setkey: A function which sets the key of the MAC

 * @setnonce: A function which sets the nonce for the mac (may be %NULL for common MAC algorithms)

 * @hash: Perform the hash operation

 * @output: Provide the output of the MAC

 * @deinit: A function which deinitializes the MAC

 * @hash_fast: Perform the MAC operation in one go

 *

 * This function will register a MAC algorithm to be used by gnutls.

 * Any algorithm registered will override the included algorithms and

 * by convention kernel implemented algorithms have priority of 90

 *  and CPU-assisted of 80.

 * The algorithm with the lowest priority will be used by gnutls.

 *

 * Deprecated: since 3.7.0 it is no longer possible to override cipher implementation

 *

 * Returns: %GNUTLS_E_SUCCESS on success, otherwise a negative error code.

 *

 * Since: 3.4.0

 **/

int gnutls_crypto_register_mac(gnutls_mac_algorithm_t algorithm, int priority,

             gnutls_mac_init_func init,

             gnutls_mac_setkey_func setkey,

             gnutls_mac_setnonce_func setnonce,

             gnutls_mac_hash_func hash,

             gnutls_mac_output_func output,

             gnutls_mac_deinit_func deinit,

             gnutls_mac_fast_func hash_fast)

{

  _gnutls_debug_log(

    "called the deprecated gnutls_crypto_register_mac()\n");

  return 0;

}

/**

 * gnutls_crypto_register_digest:

 * @algorithm: is the gnutls digest identifier

 * @priority: is the priority of the algorithm

 * @init: A function which initializes the digest

 * @hash: Perform the hash operation

 * @output: Provide the output of the digest

 * @deinit: A function which deinitializes the digest

 * @hash_fast: Perform the digest operation in one go

 *

 * This function will register a digest algorithm to be used by gnutls.

 * Any algorithm registered will override the included algorithms and

 * by convention kernel implemented algorithms have priority of 90

 *  and CPU-assisted of 80.

 * The algorithm with the lowest priority will be used by gnutls.

 *

 * Deprecated: since 3.7.0 it is no longer possible to override cipher implementation

 *

 * Returns: %GNUTLS_E_SUCCESS on success, otherwise a negative error code.

 *

 * Since: 3.4.0

 **/

int gnutls_crypto_register_digest(gnutls_digest_algorithm_t algorithm,

          int priority, gnutls_digest_init_func init,

          gnutls_digest_hash_func hash,

          gnutls_digest_output_func output,

          gnutls_digest_deinit_func deinit,

          gnutls_digest_fast_func hash_fast)

{

  _gnutls_debug_log(

    "called the deprecated gnutls_crypto_register_digest()\n");

  return 0;

}