/*

 * Copyright (C) 2011-2012 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 "gnutls_int.h"

#include <algorithms.h>

#include "errors.h"

#include <x509/common.h>

#include <pk.h>

#include "c-strcase.h"

/* Supported ECC curves

 */

static SYSTEM_CONFIG_OR_CONST gnutls_ecc_curve_entry_st ecc_curves[] = {

#ifdef ENABLE_NON_SUITEB_CURVES

  {

   .name = "SECP192R1",

   .oid = "1.2.840.10045.3.1.1",

   .id = GNUTLS_ECC_CURVE_SECP192R1,

   .group = GNUTLS_GROUP_SECP192R1,

   .pk = GNUTLS_PK_ECDSA,

   .size = 24,

   .supported = 1,

   },

  {

   .name = "SECP224R1",

   .oid = "1.3.132.0.33",

   .id = GNUTLS_ECC_CURVE_SECP224R1,

   .group = GNUTLS_GROUP_SECP224R1,

   .pk = GNUTLS_PK_ECDSA,

   .size = 28,

   .supported = 1,

   },

#endif

  {

   .name = "SECP256R1",

   .oid = "1.2.840.10045.3.1.7",

   .id = GNUTLS_ECC_CURVE_SECP256R1,

   .group = GNUTLS_GROUP_SECP256R1,

   .pk = GNUTLS_PK_ECDSA,

   .size = 32,

   .supported = 1,

   },

  {

   .name = "SECP384R1",

   .oid = "1.3.132.0.34",

   .id = GNUTLS_ECC_CURVE_SECP384R1,

   .group = GNUTLS_GROUP_SECP384R1,

   .pk = GNUTLS_PK_ECDSA,

   .size = 48,

   .supported = 1,

   },

  {

   .name = "SECP521R1",

   .oid = "1.3.132.0.35",

   .id = GNUTLS_ECC_CURVE_SECP521R1,

   .group = GNUTLS_GROUP_SECP521R1,

   .pk = GNUTLS_PK_ECDSA,

   .size = 66,

   .supported = 1,

   },

  {

   .name = "X25519",

   .oid = ECDH_X25519_OID,

   .id = GNUTLS_ECC_CURVE_X25519,

   .group = GNUTLS_GROUP_X25519,

   .pk = GNUTLS_PK_ECDH_X25519,

   .size = 32,

   .supported = 1,

   },

  {

   .name = "Ed25519",

   .oid = SIG_EDDSA_SHA512_OID,

   .id = GNUTLS_ECC_CURVE_ED25519,

   .pk = GNUTLS_PK_EDDSA_ED25519,

   .size = 32,

   .sig_size = 64,

   .supported = 1,

   },

  {

   .name = "X448",

   .oid = ECDH_X448_OID,

   .id = GNUTLS_ECC_CURVE_X448,

   .pk = GNUTLS_PK_ECDH_X448,

   .size = 56,

   .supported = 1,

   },

  {

   .name = "Ed448",

   .oid = SIG_ED448_OID,

   .id = GNUTLS_ECC_CURVE_ED448,

   .pk = GNUTLS_PK_EDDSA_ED448,

   .size = 57,

   .sig_size = 114,

   .supported = 1,

   },

#if ENABLE_GOST

  /* Curves for usage in GOST digital signature algorithm (GOST R

   * 34.10-2001/-2012) and key agreement (VKO GOST R 34.10-2001/-2012).

   *

   * Historically CryptoPro has defined three 256-bit curves for use with

   * digital signature algorithm (CryptoPro-A, -B, -C).

   *

   * Also it has reissues two of them with different OIDs for key

   * exchange (CryptoPro-XchA = CryptoPro-A and CryptoPro-XchB =

   * CryptoPro-C).

   *

   * Then TC26 (Standard committee working on cryptographic standards) has

   * defined one 256-bit curve (TC26-256-A) and three 512-bit curves

   * (TC26-512-A, -B, -C).

   *

   * And finally TC26 has reissues original CryptoPro curves under their

   * own OID namespace (TC26-256-B = CryptoPro-A, TC26-256-C =

   * CryptoPro-B and TC26-256-D = CryptoPro-C).

   *

   * CryptoPro OIDs are usable for both GOST R 34.10-2001 and

   * GOST R 34.10-2012 keys (thus they have GNUTLS_PK_UNKNOWN in this

   * table).

   * TC26 OIDs are usable only for GOST R 34.10-2012 keys.

   */

  {

   .name = "CryptoPro-A",

   .oid = "1.2.643.2.2.35.1",

   .id = GNUTLS_ECC_CURVE_GOST256CPA,

   .group = GNUTLS_GROUP_GC256B,

   .pk = GNUTLS_PK_UNKNOWN,

   .size = 32,

   .gost_curve = 1,

   .supported = 1,

   },

  {

   .name = "CryptoPro-B",

   .oid = "1.2.643.2.2.35.2",

   .id = GNUTLS_ECC_CURVE_GOST256CPB,

   .group = GNUTLS_GROUP_GC256C,

   .pk = GNUTLS_PK_UNKNOWN,

   .size = 32,

   .gost_curve = 1,

   .supported = 1,

   },

  {

   .name = "CryptoPro-C",

   .oid = "1.2.643.2.2.35.3",

   .id = GNUTLS_ECC_CURVE_GOST256CPC,

   .group = GNUTLS_GROUP_GC256D,

   .pk = GNUTLS_PK_UNKNOWN,

   .size = 32,

   .gost_curve = 1,

   .supported = 1,

   },

  {

   .name = "CryptoPro-XchA",

   .oid = "1.2.643.2.2.36.0",

   .id = GNUTLS_ECC_CURVE_GOST256CPXA,

   .group = GNUTLS_GROUP_GC256B,

   .pk = GNUTLS_PK_UNKNOWN,

   .size = 32,

   .gost_curve = 1,

   .supported = 1,

   },

  {

   .name = "CryptoPro-XchB",

   .oid = "1.2.643.2.2.36.1",

   .id = GNUTLS_ECC_CURVE_GOST256CPXB,

   .group = GNUTLS_GROUP_GC256D,

   .pk = GNUTLS_PK_UNKNOWN,

   .size = 32,

   .gost_curve = 1,

   .supported = 1,

   },

  {

   .name = "TC26-256-A",

   .oid = "1.2.643.7.1.2.1.1.1",

   .id = GNUTLS_ECC_CURVE_GOST256A,

   .group = GNUTLS_GROUP_GC256A,

   .pk = GNUTLS_PK_GOST_12_256,

   .size = 32,

   .gost_curve = 1,

   .supported = 1,

   },

  {

   .name = "TC26-256-B",

   .oid = "1.2.643.7.1.2.1.1.2",

   .id = GNUTLS_ECC_CURVE_GOST256B,

   .group = GNUTLS_GROUP_GC256B,

   .pk = GNUTLS_PK_GOST_12_256,

   .size = 32,

   .gost_curve = 1,

   .supported = 1,

   },

  {

   .name = "TC26-256-C",

   .oid = "1.2.643.7.1.2.1.1.3",

   .id = GNUTLS_ECC_CURVE_GOST256C,

   .group = GNUTLS_GROUP_GC256C,

   .pk = GNUTLS_PK_GOST_12_256,

   .size = 32,

   .gost_curve = 1,

   .supported = 1,

   },

  {

   .name = "TC26-256-D",

   .oid = "1.2.643.7.1.2.1.1.4",

   .id = GNUTLS_ECC_CURVE_GOST256D,

   .group = GNUTLS_GROUP_GC256D,

   .pk = GNUTLS_PK_GOST_12_256,

   .size = 32,

   .gost_curve = 1,

   .supported = 1,

   },

  {

   .name = "TC26-512-A",

   .oid = "1.2.643.7.1.2.1.2.1",

   .id = GNUTLS_ECC_CURVE_GOST512A,

   .group = GNUTLS_GROUP_GC512A,

   .pk = GNUTLS_PK_GOST_12_512,

   .size = 64,

   .gost_curve = 1,

   .supported = 1,

   },

  {

   .name = "TC26-512-B",

   .oid = "1.2.643.7.1.2.1.2.2",

   .id = GNUTLS_ECC_CURVE_GOST512B,

   .group = GNUTLS_GROUP_GC512B,

   .pk = GNUTLS_PK_GOST_12_512,

   .size = 64,

   .gost_curve = 1,

   .supported = 1,

   },

  {

   .name = "TC26-512-C",

   .oid = "1.2.643.7.1.2.1.2.3",

   .id = GNUTLS_ECC_CURVE_GOST512C,

   .group = GNUTLS_GROUP_GC512C,

   .pk = GNUTLS_PK_GOST_12_512,

   .size = 64,

   .gost_curve = 1,

   .supported = 1,

   },

#endif

  {0, 0, 0}

};

#define GNUTLS_ECC_CURVE_LOOP(b) \

  { const gnutls_ecc_curve_entry_st *p; \

    for(p = ecc_curves; p->name != NULL; p++) { b ; } }

/**

 * gnutls_ecc_curve_list:

 *

 * Get the list of supported elliptic curves.

 *

 * This function is not thread safe.

 *

 * Returns: Return a (0)-terminated list of #gnutls_ecc_curve_t

 *   integers indicating the available curves.

 **/

const gnutls_ecc_curve_t *gnutls_ecc_curve_list(void)

{

  static gnutls_ecc_curve_t supported_curves[MAX_ALGOS] = { 0 };

  if (supported_curves[0] == 0) {

    int i = 0;

    GNUTLS_ECC_CURVE_LOOP(if

              (p->supported

               && _gnutls_pk_curve_exists(p->id))

              supported_curves[i++] = p->id;) ;

    supported_curves[i++] = 0;

  }

  return supported_curves;

}

unsigned _gnutls_ecc_curve_is_supported(gnutls_ecc_curve_t curve)

{

  GNUTLS_ECC_CURVE_LOOP(if

            (p->id == curve && p->supported

             && _gnutls_pk_curve_exists(p->id))

            return 1;) ;

  return 0;

}

/**

 * gnutls_oid_to_ecc_curve:

 * @oid: is a curve's OID

 *

 * Returns: return a #gnutls_ecc_curve_t value corresponding to

 *   the specified OID, or %GNUTLS_ECC_CURVE_INVALID on error.

 *

 * Since: 3.4.3

 **/

gnutls_ecc_curve_t gnutls_oid_to_ecc_curve(const char *oid)

{

  gnutls_ecc_curve_t ret = GNUTLS_ECC_CURVE_INVALID;

  GNUTLS_ECC_CURVE_LOOP(if

            (p->oid != NULL && c_strcasecmp(p->oid, oid) == 0

             && p->supported

             && _gnutls_pk_curve_exists(p->id)) {

            ret = p->id; break;}

  ) ;

  return ret;

}

/**

 * gnutls_ecc_curve_get_id:

 * @name: is a curve name

 *

 * The names are compared in a case insensitive way.

 *

 * Returns: return a #gnutls_ecc_curve_t value corresponding to

 *   the specified curve, or %GNUTLS_ECC_CURVE_INVALID on error.

 *

 * Since: 3.4.3

 **/

gnutls_ecc_curve_t gnutls_ecc_curve_get_id(const char *name)

{

  gnutls_ecc_curve_t ret = GNUTLS_ECC_CURVE_INVALID;

  GNUTLS_ECC_CURVE_LOOP(if

            (c_strcasecmp(p->name, name) == 0 && p->supported

             && _gnutls_pk_curve_exists(p->id)) {

            ret = p->id; break;}

  ) ;

  return ret;

}

/* This is only called by cfg_apply in priority.c, in blocklisting mode. */

int _gnutls_ecc_curve_mark_disabled(gnutls_ecc_curve_t curve)

{

  gnutls_ecc_curve_entry_st *p;

  for (p = ecc_curves; p->name != NULL; p++) {

    if (p->id == curve) {

      p->supported = false;

      return 0;

    }

  }

  return gnutls_assert_val(GNUTLS_E_INVALID_REQUEST);

}

/* This is only called by cfg_apply in priority.c, in allowlisting mode. */

void _gnutls_ecc_curve_mark_disabled_all(void)

{

  gnutls_ecc_curve_entry_st *p;

  for (p = ecc_curves; p->name != NULL; p++) {

    p->supported = false;

    p->supported_revertible = true;

  }

}

int

_gnutls_ecc_curve_set_enabled(gnutls_ecc_curve_t curve, unsigned int enabled)

{

  gnutls_ecc_curve_entry_st *p;

  for (p = ecc_curves; p->name != NULL; p++) {

    if (p->id == curve) {

      if (!p->supported_revertible) {

        return

            gnutls_assert_val(GNUTLS_E_INVALID_REQUEST);

      }

      p->supported = enabled;

      return 0;

    }

  }

  return gnutls_assert_val(GNUTLS_E_INVALID_REQUEST);

}

static int _gnutls_ecc_pk_compatible(const gnutls_ecc_curve_entry_st * p,

             gnutls_pk_algorithm_t pk)

{

  if (!p->supported || !_gnutls_pk_curve_exists(p->id))

    return 0;

  if (pk == GNUTLS_PK_GOST_01 || pk == GNUTLS_PK_GOST_12_256)

    return p->gost_curve && p->size == 32;

  return pk == p->pk;

}

/*-

 * _gnutls_ecc_bits_to_curve:

 * @bits: is a security parameter in bits

 *

 * Returns: return a #gnutls_ecc_curve_t value corresponding to

 *   the specified bit length, or %GNUTLS_ECC_CURVE_INVALID on error.

 -*/

gnutls_ecc_curve_t _gnutls_ecc_bits_to_curve(gnutls_pk_algorithm_t pk, int bits)

{

  gnutls_ecc_curve_t ret;

  if (pk == GNUTLS_PK_ECDSA)

    ret = GNUTLS_ECC_CURVE_SECP256R1;

  else if (pk == GNUTLS_PK_GOST_01 || pk == GNUTLS_PK_GOST_12_256)

    ret = GNUTLS_ECC_CURVE_GOST256CPA;

  else if (pk == GNUTLS_PK_GOST_12_512)

    ret = GNUTLS_ECC_CURVE_GOST512A;

  else

    ret = GNUTLS_ECC_CURVE_ED25519;

  GNUTLS_ECC_CURVE_LOOP(if (_gnutls_ecc_pk_compatible(p, pk)

          && 8 * p->size >= (unsigned)bits) {

            ret = p->id; break;}

  ) ;

  return ret;

}

/**

 * gnutls_ecc_curve_get_name:

 * @curve: is an ECC curve

 *

 * Convert a #gnutls_ecc_curve_t value to a string.

 *

 * Returns: a string that contains the name of the specified

 *   curve or %NULL.

 *

 * Since: 3.0

 **/

const char *gnutls_ecc_curve_get_name(gnutls_ecc_curve_t curve)

{

  const char *ret = NULL;

  GNUTLS_ECC_CURVE_LOOP(if (p->id == curve) {

            ret = p->name; break;}

  ) ;

  return ret;

}

/**

 * gnutls_ecc_curve_get_oid:

 * @curve: is an ECC curve

 *

 * Convert a #gnutls_ecc_curve_t value to its object identifier.

 *

 * Returns: a string that contains the OID of the specified

 *   curve or %NULL.

 *

 * Since: 3.4.3

 **/

const char *gnutls_ecc_curve_get_oid(gnutls_ecc_curve_t curve)

{

  const char *ret = NULL;

  GNUTLS_ECC_CURVE_LOOP(if (p->id == curve) {

            ret = p->oid; break;}

  ) ;

  return ret;

}

/*-

 * _gnutls_ecc_curve_get_params:

 * @curve: is an ECC curve

 *

 * Returns the information on a curve.

 *

 * Returns: a pointer to #gnutls_ecc_curve_entry_st or %NULL.

 -*/

const gnutls_ecc_curve_entry_st

    * _gnutls_ecc_curve_get_params(gnutls_ecc_curve_t curve)

{

  const gnutls_ecc_curve_entry_st *ret = NULL;

  GNUTLS_ECC_CURVE_LOOP(if (p->id == curve) {

            ret = p; break;}

  ) ;

  return ret;

}

/**

 * gnutls_ecc_curve_get_size:

 * @curve: is an ECC curve

 *

 * Returns: the size in bytes of the curve or 0 on failure.

 *

 * Since: 3.0

 **/

int gnutls_ecc_curve_get_size(gnutls_ecc_curve_t curve)

{

  int ret = 0;

  GNUTLS_ECC_CURVE_LOOP(if (p->id == curve) {

            ret = p->size; break;}

  ) ;

  return ret;

}

/**

 * gnutls_ecc_curve_get_pk:

 * @curve: is an ECC curve

 *

 * Returns: the public key algorithm associated with the named curve or %GNUTLS_PK_UNKNOWN.

 *

 * Since: 3.5.0

 **/

gnutls_pk_algorithm_t gnutls_ecc_curve_get_pk(gnutls_ecc_curve_t curve)

{

  int ret = GNUTLS_PK_UNKNOWN;

  GNUTLS_ECC_CURVE_LOOP(if (p->id == curve && p->supported) {

            ret = p->pk; break;}

  ) ;

  return ret;

}

/**

 * _gnutls_ecc_curve_get_group:

 * @curve: is an ECC curve

 *

 * Returns: the group associated with the named curve or %GNUTLS_GROUP_INVALID.

 *

 * Since: 3.6.11

 */

gnutls_group_t _gnutls_ecc_curve_get_group(gnutls_ecc_curve_t curve)

{

  gnutls_group_t ret = GNUTLS_GROUP_INVALID;

  GNUTLS_ECC_CURVE_LOOP(if

            (p->id == curve && p->supported

             && _gnutls_pk_curve_exists(p->id)) {

            ret = p->group; break;}

  ) ;

  return ret;

}