/* $OpenBSD: ec_key.c,v 1.26 2021/04/20 17:23:37 tb Exp $ */

/*

 * Written by Nils Larsch for the OpenSSL project.

 */

/* ====================================================================

 * Copyright (c) 1998-2005 The OpenSSL Project.  All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 *

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 *

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in

 *    the documentation and/or other materials provided with the

 *    distribution.

 *

 * 3. All advertising materials mentioning features or use of this

 *    software must display the following acknowledgment:

 *    "This product includes software developed by the OpenSSL Project

 *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"

 *

 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to

 *    endorse or promote products derived from this software without

 *    prior written permission. For written permission, please contact

 *    openssl-core@openssl.org.

 *

 * 5. Products derived from this software may not be called "OpenSSL"

 *    nor may "OpenSSL" appear in their names without prior written

 *    permission of the OpenSSL Project.

 *

 * 6. Redistributions of any form whatsoever must retain the following

 *    acknowledgment:

 *    "This product includes software developed by the OpenSSL Project

 *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"

 *

 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY

 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR

 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT

 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;

 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,

 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED

 * OF THE POSSIBILITY OF SUCH DAMAGE.

 * ====================================================================

 *

 * This product includes cryptographic software written by Eric Young

 * (eay@cryptsoft.com).  This product includes software written by Tim

 * Hudson (tjh@cryptsoft.com).

 *

 */

/* ====================================================================

 * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.

 * Portions originally developed by SUN MICROSYSTEMS, INC., and

 * contributed to the OpenSSL project.

 */

#include <string.h>

#include <openssl/opensslconf.h>

#ifndef OPENSSL_NO_ENGINE

#include <openssl/engine.h>

#endif

#include <openssl/err.h>

#include "bn_lcl.h"

#include "ec_lcl.h"

EC_KEY *

EC_KEY_new(void)

{

  return EC_KEY_new_method(NULL);

}

EC_KEY *

EC_KEY_new_by_curve_name(int nid)

{

  EC_KEY *ret = EC_KEY_new();

  if (ret == NULL)

    return NULL;

  ret->group = EC_GROUP_new_by_curve_name(nid);

  if (ret->group == NULL) {

    EC_KEY_free(ret);

    return NULL;

  }

  if (ret->meth->set_group != NULL &&

      ret->meth->set_group(ret, ret->group) == 0) {

    EC_KEY_free(ret);

    return NULL;

  }

  return ret;

}

void 

EC_KEY_free(EC_KEY * r)

{

  int i;

  if (r == NULL)

    return;

  i = CRYPTO_add(&r->references, -1, CRYPTO_LOCK_EC);

  if (i > 0)

    return;

  if (r->meth != NULL && r->meth->finish != NULL)

    r->meth->finish(r);

#ifndef OPENSSL_NO_ENGINE

  ENGINE_finish(r->engine);

#endif

  CRYPTO_free_ex_data(CRYPTO_EX_INDEX_EC_KEY, r, &r->ex_data);

  EC_GROUP_free(r->group);

  EC_POINT_free(r->pub_key);

  BN_clear_free(r->priv_key);

  EC_EX_DATA_free_all_data(&r->method_data);

  freezero(r, sizeof(EC_KEY));

}

EC_KEY *

EC_KEY_copy(EC_KEY * dest, const EC_KEY * src)

{

  EC_EXTRA_DATA *d;

  if (dest == NULL || src == NULL) {

    ECerror(ERR_R_PASSED_NULL_PARAMETER);

    return NULL;

  }

  if (src->meth != dest->meth) {

    if (dest->meth != NULL && dest->meth->finish != NULL)

      dest->meth->finish(dest);

#ifndef OPENSSL_NO_ENGINE

    if (ENGINE_finish(dest->engine) == 0)

      return 0;

    dest->engine = NULL;

#endif

  }

  /* copy the parameters */

  if (src->group) {

    const EC_METHOD *meth = EC_GROUP_method_of(src->group);

    /* clear the old group */

    EC_GROUP_free(dest->group);

    dest->group = EC_GROUP_new(meth);

    if (dest->group == NULL)

      return NULL;

    if (!EC_GROUP_copy(dest->group, src->group))

      return NULL;

  }

  /* copy the public key */

  if (src->pub_key && src->group) {

    EC_POINT_free(dest->pub_key);

    dest->pub_key = EC_POINT_new(src->group);

    if (dest->pub_key == NULL)

      return NULL;

    if (!EC_POINT_copy(dest->pub_key, src->pub_key))

      return NULL;

  }

  /* copy the private key */

  if (src->priv_key) {

    if (dest->priv_key == NULL) {

      dest->priv_key = BN_new();

      if (dest->priv_key == NULL)

        return NULL;

    }

    if (!BN_copy(dest->priv_key, src->priv_key))

      return NULL;

  }

  /* copy method/extra data */

  EC_EX_DATA_free_all_data(&dest->method_data);

  for (d = src->method_data; d != NULL; d = d->next) {

    void *t = d->dup_func(d->data);

    if (t == NULL)

      return 0;

    if (!EC_EX_DATA_set_data(&dest->method_data, t, d->dup_func,

        d->free_func, d->clear_free_func))

      return 0;

  }

  /* copy the rest */

  dest->enc_flag = src->enc_flag;

  dest->conv_form = src->conv_form;

  dest->version = src->version;

  dest->flags = src->flags;

  if (!CRYPTO_dup_ex_data(CRYPTO_EX_INDEX_EC_KEY, &dest->ex_data,

      &((EC_KEY *)src)->ex_data))  /* XXX const */

    return NULL;

  if (src->meth != dest->meth) {

#ifndef OPENSSL_NO_ENGINE

    if (src->engine != NULL && ENGINE_init(src->engine) == 0)

      return 0;

    dest->engine = src->engine;

#endif

    dest->meth = src->meth;

  }

  if (src->meth != NULL && src->meth->copy != NULL &&

      src->meth->copy(dest, src) == 0)

    return 0;

  return dest;

}

EC_KEY *

EC_KEY_dup(const EC_KEY * ec_key)

{

  EC_KEY *ret;

  if ((ret = EC_KEY_new_method(ec_key->engine)) == NULL)

    return NULL;

  if (EC_KEY_copy(ret, ec_key) == NULL) {

    EC_KEY_free(ret);

    return NULL;

  }

  return ret;

}

int 

EC_KEY_up_ref(EC_KEY * r)

{

  int i = CRYPTO_add(&r->references, 1, CRYPTO_LOCK_EC);

  return ((i > 1) ? 1 : 0);

}

int

EC_KEY_set_ex_data(EC_KEY *r, int idx, void *arg)

{

  return CRYPTO_set_ex_data(&r->ex_data, idx, arg);

}

void *

EC_KEY_get_ex_data(const EC_KEY *r, int idx)

{

  return CRYPTO_get_ex_data(&r->ex_data, idx);

}

int

EC_KEY_generate_key(EC_KEY *eckey)

{

  if (eckey->meth->keygen != NULL)

    return eckey->meth->keygen(eckey);

  ECerror(EC_R_NOT_IMPLEMENTED);

  return 0;

}

int

ossl_ec_key_gen(EC_KEY *eckey)

{

  int ok = 0;

  BN_CTX *ctx = NULL;

  BIGNUM *priv_key = NULL, *order = NULL;

  EC_POINT *pub_key = NULL;

  if (!eckey || !eckey->group) {

    ECerror(ERR_R_PASSED_NULL_PARAMETER);

    return 0;

  }

  if ((order = BN_new()) == NULL)

    goto err;

  if ((ctx = BN_CTX_new()) == NULL)

    goto err;

  if ((priv_key = eckey->priv_key) == NULL) {

    if ((priv_key = BN_new()) == NULL)

      goto err;

  }

  if (!EC_GROUP_get_order(eckey->group, order, ctx))

    goto err;

  if (!bn_rand_interval(priv_key, BN_value_one(), order))

    goto err;

  if ((pub_key = eckey->pub_key) == NULL) {

    if ((pub_key = EC_POINT_new(eckey->group)) == NULL)

      goto err;

  }

  if (!EC_POINT_mul(eckey->group, pub_key, priv_key, NULL, NULL, ctx))

    goto err;

  eckey->priv_key = priv_key;

  eckey->pub_key = pub_key;

  ok = 1;

 err:

  BN_free(order);

  if (eckey->pub_key == NULL)

    EC_POINT_free(pub_key);

  if (eckey->priv_key == NULL)

    BN_free(priv_key);

  BN_CTX_free(ctx);

  return (ok);

}

int 

EC_KEY_check_key(const EC_KEY * eckey)

{

  int ok = 0;

  BN_CTX *ctx = NULL;

  const BIGNUM *order = NULL;

  EC_POINT *point = NULL;

  if (!eckey || !eckey->group || !eckey->pub_key) {

    ECerror(ERR_R_PASSED_NULL_PARAMETER);

    return 0;

  }

  if (EC_POINT_is_at_infinity(eckey->group, eckey->pub_key) > 0) {

    ECerror(EC_R_POINT_AT_INFINITY);

    goto err;

  }

  if ((ctx = BN_CTX_new()) == NULL)

    goto err;

  if ((point = EC_POINT_new(eckey->group)) == NULL)

    goto err;

  /* testing whether the pub_key is on the elliptic curve */

  if (EC_POINT_is_on_curve(eckey->group, eckey->pub_key, ctx) <= 0) {

    ECerror(EC_R_POINT_IS_NOT_ON_CURVE);

    goto err;

  }

  /* testing whether pub_key * order is the point at infinity */

  order = &eckey->group->order;

  if (BN_is_zero(order)) {

    ECerror(EC_R_INVALID_GROUP_ORDER);

    goto err;

  }

  if (!EC_POINT_mul(eckey->group, point, NULL, eckey->pub_key, order, ctx)) {

    ECerror(ERR_R_EC_LIB);

    goto err;

  }

  if (EC_POINT_is_at_infinity(eckey->group, point) <= 0) {

    ECerror(EC_R_WRONG_ORDER);

    goto err;

  }

  /*

   * in case the priv_key is present : check if generator * priv_key ==

   * pub_key

   */

  if (eckey->priv_key) {

    if (BN_cmp(eckey->priv_key, order) >= 0) {

      ECerror(EC_R_WRONG_ORDER);

      goto err;

    }

    if (!EC_POINT_mul(eckey->group, point, eckey->priv_key,

      NULL, NULL, ctx)) {

      ECerror(ERR_R_EC_LIB);

      goto err;

    }

    if (EC_POINT_cmp(eckey->group, point, eckey->pub_key,

      ctx) != 0) {

      ECerror(EC_R_INVALID_PRIVATE_KEY);

      goto err;

    }

  }

  ok = 1;

 err:

  BN_CTX_free(ctx);

  EC_POINT_free(point);

  return (ok);

}

int 

EC_KEY_set_public_key_affine_coordinates(EC_KEY * key, BIGNUM * x, BIGNUM * y)

{

  BN_CTX *ctx = NULL;

  BIGNUM *tx, *ty;

  EC_POINT *point = NULL;

  int ok = 0;

  if (!key || !key->group || !x || !y) {

    ECerror(ERR_R_PASSED_NULL_PARAMETER);

    return 0;

  }

  ctx = BN_CTX_new();

  if (!ctx)

    goto err;

  point = EC_POINT_new(key->group);

  if (!point)

    goto err;

  if ((tx = BN_CTX_get(ctx)) == NULL)

    goto err;

  if ((ty = BN_CTX_get(ctx)) == NULL)

    goto err;

  if (!EC_POINT_set_affine_coordinates(key->group, point, x, y, ctx))

    goto err;

  if (!EC_POINT_get_affine_coordinates(key->group, point, tx, ty, ctx))

    goto err;

  /*

   * Check if retrieved coordinates match originals: if not values are

   * out of range.

   */

  if (BN_cmp(x, tx) || BN_cmp(y, ty)) {

    ECerror(EC_R_COORDINATES_OUT_OF_RANGE);

    goto err;

  }

  if (!EC_KEY_set_public_key(key, point))

    goto err;

  if (EC_KEY_check_key(key) == 0)

    goto err;

  ok = 1;

 err:

  BN_CTX_free(ctx);

  EC_POINT_free(point);

  return ok;

}

const EC_GROUP *

EC_KEY_get0_group(const EC_KEY * key)

{

  return key->group;

}

int 

EC_KEY_set_group(EC_KEY * key, const EC_GROUP * group)

{

  if (key->meth->set_group != NULL &&

      key->meth->set_group(key, group) == 0)

    return 0;

  EC_GROUP_free(key->group);

  key->group = EC_GROUP_dup(group);

  return (key->group == NULL) ? 0 : 1;

}

const BIGNUM *

EC_KEY_get0_private_key(const EC_KEY * key)

{

  return key->priv_key;

}

int 

EC_KEY_set_private_key(EC_KEY * key, const BIGNUM * priv_key)

{

  if (key->meth->set_private != NULL &&

      key->meth->set_private(key, priv_key) == 0)

    return 0;

  BN_clear_free(key->priv_key);

  key->priv_key = BN_dup(priv_key);

  return (key->priv_key == NULL) ? 0 : 1;

}

const EC_POINT *

EC_KEY_get0_public_key(const EC_KEY * key)

{

  return key->pub_key;

}

int 

EC_KEY_set_public_key(EC_KEY * key, const EC_POINT * pub_key)

{

  if (key->meth->set_public != NULL &&

      key->meth->set_public(key, pub_key) == 0)

    return 0;

  EC_POINT_free(key->pub_key);

  key->pub_key = EC_POINT_dup(pub_key, key->group);

  return (key->pub_key == NULL) ? 0 : 1;

}

unsigned int 

EC_KEY_get_enc_flags(const EC_KEY * key)

{

  return key->enc_flag;

}

void 

EC_KEY_set_enc_flags(EC_KEY * key, unsigned int flags)

{

  key->enc_flag = flags;

}

point_conversion_form_t 

EC_KEY_get_conv_form(const EC_KEY * key)

{

  return key->conv_form;

}

void 

EC_KEY_set_conv_form(EC_KEY * key, point_conversion_form_t cform)

{

  key->conv_form = cform;

  if (key->group != NULL)

    EC_GROUP_set_point_conversion_form(key->group, cform);

}

void *

EC_KEY_get_key_method_data(EC_KEY *key,

    void *(*dup_func) (void *),

    void (*free_func) (void *),

    void (*clear_free_func) (void *))

{

  void *ret;

  CRYPTO_r_lock(CRYPTO_LOCK_EC);

  ret = EC_EX_DATA_get_data(key->method_data, dup_func, free_func, clear_free_func);

  CRYPTO_r_unlock(CRYPTO_LOCK_EC);

  return ret;

}

void *

EC_KEY_insert_key_method_data(EC_KEY * key, void *data,

    void *(*dup_func) (void *),

    void (*free_func) (void *),

    void (*clear_free_func) (void *))

{

  EC_EXTRA_DATA *ex_data;

  CRYPTO_w_lock(CRYPTO_LOCK_EC);

  ex_data = EC_EX_DATA_get_data(key->method_data, dup_func, free_func, clear_free_func);

  if (ex_data == NULL)

    EC_EX_DATA_set_data(&key->method_data, data, dup_func, free_func, clear_free_func);

  CRYPTO_w_unlock(CRYPTO_LOCK_EC);

  return ex_data;

}

void 

EC_KEY_set_asn1_flag(EC_KEY * key, int flag)

{

  if (key->group != NULL)

    EC_GROUP_set_asn1_flag(key->group, flag);

}

int 

EC_KEY_precompute_mult(EC_KEY * key, BN_CTX * ctx)

{

  if (key->group == NULL)

    return 0;

  return EC_GROUP_precompute_mult(key->group, ctx);

}

int 

EC_KEY_get_flags(const EC_KEY * key)

{

  return key->flags;

}

void 

EC_KEY_set_flags(EC_KEY * key, int flags)

{

  key->flags |= flags;

}

void 

EC_KEY_clear_flags(EC_KEY * key, int flags)

{

  key->flags &= ~flags;

}