text: ﻿/* crypto/ec/ec_lib.c */
  /*
   * Originally written by Bodo Moeller for the OpenSSL project.
   */
  /* ====================================================================
   * Copyright (c) 1998-2003 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.
   * Binary polynomial ECC support in OpenSSL originally developed by 
   * SUN MICROSYSTEMS, INC., and contributed to the OpenSSL project.
   */
  
  #include <string.h>
  
  #include <openssl/err.h>
  #include <openssl/opensslv.h>
  
  #include "ec_lcl.h"
  
  static const char EC_version[] = "EC" OPENSSL_VERSION_PTEXT;
  
  
  /* functions for EC_GROUP objects */
  
  EC_GROUP *EC_GROUP_new(const EC_METHOD *meth)
  	{
  	EC_GROUP *ret;
  
  	if (meth == NULL)
  		{
  		ECerr(EC_F_EC_GROUP_NEW, EC_R_SLOT_FULL);
  		return NULL;
  		}
  	if (meth->group_init == 0)
  		{
  		ECerr(EC_F_EC_GROUP_NEW, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
  		return NULL;
  		}
  
  	ret = OPENSSL_malloc(sizeof *ret);
  	if (ret == NULL)
  		{
  		ECerr(EC_F_EC_GROUP_NEW, ERR_R_MALLOC_FAILURE);
  		return NULL;
  		}
  
  	ret->meth = meth;
  
  	ret->extra_data = NULL;
  
  	ret->generator = NULL;
  	BN_init(&ret->order);
  	BN_init(&ret->cofactor);
  
  	ret->curve_name = 0;	
  	ret->asn1_flag  = 0;
  	ret->asn1_form  = POINT_CONVERSION_UNCOMPRESSED;
  
  	ret->seed = NULL;
  	ret->seed_len = 0;
  
  	if (!meth->group_init(ret))
  		{
  		OPENSSL_free(ret);
  		return NULL;
  		}
  	
  	return ret;
  	}
  
  
  void EC_GROUP_free(EC_GROUP *group)
  	{
  	if (!group) return;
  
  	if (group->meth->group_finish != 0)
  		group->meth->group_finish(group);
  
  	EC_EX_DATA_free_all_data(&group->extra_data);
  
  	if (group->generator != NULL)
  		EC_POINT_free(group->generator);
  	BN_free(&group->order);
  	BN_free(&group->cofactor);
  
  	if (group->seed)
  		OPENSSL_free(group->seed);
  
  	OPENSSL_free(group);
  	}
   
  
  void EC_GROUP_clear_free(EC_GROUP *group)
  	{
  	if (!group) return;
  
  	if (group->meth->group_clear_finish != 0)
  		group->meth->group_clear_finish(group);
  	else if (group->meth->group_finish != 0)
  		group->meth->group_finish(group);
  
  	EC_EX_DATA_clear_free_all_data(&group->extra_data);
  
  	if (group->generator != NULL)
  		EC_POINT_clear_free(group->generator);
  	BN_clear_free(&group->order);
  	BN_clear_free(&group->cofactor);
  
  	if (group->seed)
  		{
  		OPENSSL_cleanse(group->seed, group->seed_len);
  		OPENSSL_free(group->seed);
  		}
  
  	OPENSSL_cleanse(group, sizeof *group);
  	OPENSSL_free(group);
  	}
  
  
  int EC_GROUP_copy(EC_GROUP *dest, const EC_GROUP *src)
  	{
  	EC_EXTRA_DATA *d;
  
  	if (dest->meth->group_copy == 0)
  		{
  		ECerr(EC_F_EC_GROUP_COPY, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
  		return 0;
  		}
  	if (dest->meth != src->meth)
  		{
  		ECerr(EC_F_EC_GROUP_COPY, EC_R_INCOMPATIBLE_OBJECTS);
  		return 0;
  		}
  	if (dest == src)
  		return 1;
  	
  	EC_EX_DATA_free_all_data(&dest->extra_data);
  
  	for (d = src->extra_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->extra_data, t, d->dup_func, d->free_func, d->clear_free_func))
  			return 0;
  		}
  
  	if (src->generator != NULL)
  		{
  		if (dest->generator == NULL)
  			{
  			dest->generator = EC_POINT_new(dest);
  			if (dest->generator == NULL) return 0;
  			}
  		if (!EC_POINT_copy(dest->generator, src->generator)) return 0;
  		}
  	else
  		{
  		/* src->generator == NULL */
  		if (dest->generator != NULL)
  			{
  			EC_POINT_clear_free(dest->generator);
  			dest->generator = NULL;
  			}
  		}
  
  	if (!BN_copy(&dest->order, &src->order)) return 0;
  	if (!BN_copy(&dest->cofactor, &src->cofactor)) return 0;
  
  	dest->curve_name = src->curve_name;
  	dest->asn1_flag  = src->asn1_flag;
  	dest->asn1_form  = src->asn1_form;
  
  	if (src->seed)
  		{
  		if (dest->seed)
  			OPENSSL_free(dest->seed);
  		dest->seed = OPENSSL_malloc(src->seed_len);
  		if (dest->seed == NULL)
  			return 0;
  		if (!memcpy(dest->seed, src->seed, src->seed_len))
  			return 0;
  		dest->seed_len = src->seed_len;
  		}
  	else
  		{
  		if (dest->seed)
  			OPENSSL_free(dest->seed);
  		dest->seed = NULL;
  		dest->seed_len = 0;
  		}
  	
  
  	return dest->meth->group_copy(dest, src);
  	}
  
  
  EC_GROUP *EC_GROUP_dup(const EC_GROUP *a)
  	{
  	EC_GROUP *t = NULL;
  	int ok = 0;
  
  	if (a == NULL) return NULL;
  
  	if ((t = EC_GROUP_new(a->meth)) == NULL) return(NULL);
  	if (!EC_GROUP_copy(t, a)) goto err;
  
  	ok = 1;
  
    err:	
  	if (!ok)
  		{
  		if (t) EC_GROUP_free(t);
  		return NULL;
  		}
  	else return t;
  	}
  
  
  const EC_METHOD *EC_GROUP_method_of(const EC_GROUP *group)
  	{
  	return group->meth;
  	}
  
  
  int EC_METHOD_get_field_type(const EC_METHOD *meth)
          {
          return meth->field_type;
          }
  
  
  int EC_GROUP_set_generator(EC_GROUP *group, const EC_POINT *generator, const BIGNUM *order, const BIGNUM *cofactor)
  	{
  	if (generator == NULL)
  		{
  		ECerr(EC_F_EC_GROUP_SET_GENERATOR, ERR_R_PASSED_NULL_PARAMETER);
  		return 0   ;
  		}
  
  	if (group->generator == NULL)
  		{
  		group->generator = EC_POINT_new(group);
  		if (group->generator == NULL) return 0;
  		}
  	if (!EC_POINT_copy(group->generator, generator)) return 0;
  
  	if (order != NULL)
  		{ if (!BN_copy(&group->order, order)) return 0; }	
  	else
  		BN_zero(&group->order);
  
  	if (cofactor != NULL)
  		{ if (!BN_copy(&group->cofactor, cofactor)) return 0; }	
  	else
  		BN_zero(&group->cofactor);
  
  	return 1;
  	}
  
  
  const EC_POINT *EC_GROUP_get0_generator(const EC_GROUP *group)
  	{
  	return group->generator;
  	}
  
  
  int EC_GROUP_get_order(const EC_GROUP *group, BIGNUM *order, BN_CTX *ctx)
  	{
  	if (!BN_copy(order, &group->order))
  		return 0;
  
  	return !BN_is_zero(order);
  	}
  
  
  int EC_GROUP_get_cofactor(const EC_GROUP *group, BIGNUM *cofactor, BN_CTX *ctx)
  	{
  	if (!BN_copy(cofactor, &group->cofactor))
  		return 0;
  
  	return !BN_is_zero(&group->cofactor);
  	}
  
  
  void EC_GROUP_set_curve_name(EC_GROUP *group, int nid)
  	{
  	group->curve_name = nid;
  	}
  
  
  int EC_GROUP_get_curve_name(const EC_GROUP *group)
  	{
  	return group->curve_name;
  	}
  
  
  void EC_GROUP_set_asn1_flag(EC_GROUP *group, int flag)
  	{
  	group->asn1_flag = flag;
  	}
  
  
  int EC_GROUP_get_asn1_flag(const EC_GROUP *group)
  	{
  	return group->asn1_flag;
  	}
  
  
  void EC_GROUP_set_point_conversion_form(EC_GROUP *group, 
                                          point_conversion_form_t form)
  	{
  	group->asn1_form = form;
  	}
  
  
  point_conversion_form_t EC_GROUP_get_point_conversion_form(const EC_GROUP *group)
  	{
  	return group->asn1_form;
  	}
  
  
  size_t EC_GROUP_set_seed(EC_GROUP *group, const unsigned char *p, size_t len)
  	{
  	if (group->seed)
  		{
  		OPENSSL_free(group->seed);
  		group->seed = NULL;
  		group->seed_len = 0;
  		}
  
  	if (!len || !p)
  		return 1;
  
  	if ((group->seed = OPENSSL_malloc(len)) == NULL)
  		return 0;
  	memcpy(group->seed, p, len);
  	group->seed_len = len;
  
  	return len;
  	}
  
  
  unsigned char *EC_GROUP_get0_seed(const EC_GROUP *group)
  	{
  	return group->seed;
  	}
  
  
  size_t EC_GROUP_get_seed_len(const EC_GROUP *group)
  	{
  	return group->seed_len;
  	}
  
  
  int EC_GROUP_set_curve_GFp(EC_GROUP *group, const BIGNUM *p, const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx)
  	{
  	if (group->meth->group_set_curve == 0)
  		{
  		ECerr(EC_F_EC_GROUP_SET_CURVE_GFP, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
  		return 0;
  		}
  	return group->meth->group_set_curve(group, p, a, b, ctx);
  	}
  
  
  int EC_GROUP_get_curve_GFp(const EC_GROUP *group, BIGNUM *p, BIGNUM *a, BIGNUM *b, BN_CTX *ctx)
  	{
  	if (group->meth->group_get_curve == 0)
  		{
  		ECerr(EC_F_EC_GROUP_GET_CURVE_GFP, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
  		return 0;
  		}
  	return group->meth->group_get_curve(group, p, a, b, ctx);
  	}
  
  #ifndef OPENSSL_NO_EC2M
  int EC_GROUP_set_curve_GF2m(EC_GROUP *group, const BIGNUM *p, const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx)
  	{
  	if (group->meth->group_set_curve == 0)
  		{
  		ECerr(EC_F_EC_GROUP_SET_CURVE_GF2M, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
  		return 0;
  		}
  	return group->meth->group_set_curve(group, p, a, b, ctx);
  	}
  
  
  int EC_GROUP_get_curve_GF2m(const EC_GROUP *group, BIGNUM *p, BIGNUM *a, BIGNUM *b, BN_CTX *ctx)
  	{
  	if (group->meth->group_get_curve == 0)
  		{
  		ECerr(EC_F_EC_GROUP_GET_CURVE_GF2M, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
  		return 0;
  		}
  	return group->meth->group_get_curve(group, p, a, b, ctx);
  	}
  #endif
  
  int EC_GROUP_get_degree(const EC_GROUP *group)
  	{
  	if (group->meth->group_get_degree == 0)
  		{
  		ECerr(EC_F_EC_GROUP_GET_DEGREE, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
  		return 0;
  		}
  	return group->meth->group_get_degree(group);
  	}
  
  
  int EC_GROUP_check_discriminant(const EC_GROUP *group, BN_CTX *ctx)
  	{
  	if (group->meth->group_check_discriminant == 0)
  		{
  		ECerr(EC_F_EC_GROUP_CHECK_DISCRIMINANT, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
  		return 0;
  		}
  	return group->meth->group_check_discriminant(group, ctx);
  	}
  
  
  int EC_GROUP_cmp(const EC_GROUP *a, const EC_GROUP *b, BN_CTX *ctx)
  	{
  	int    r = 0;
  	BIGNUM *a1, *a2, *a3, *b1, *b2, *b3;
  	BN_CTX *ctx_new = NULL;
  
  	/* compare the field types*/
  	if (EC_METHOD_get_field_type(EC_GROUP_method_of(a)) !=
  	    EC_METHOD_get_field_type(EC_GROUP_method_of(b)))
  		return 1;
  	/* compare the curve name (if present in both) */
  	if (EC_GROUP_get_curve_name(a) && EC_GROUP_get_curve_name(b) &&
  	    EC_GROUP_get_curve_name(a) != EC_GROUP_get_curve_name(b))
  		return 1;
  
  	if (!ctx)
  		ctx_new = ctx = BN_CTX_new();
  	if (!ctx)
  		return -1;
  	
  	BN_CTX_start(ctx);
  	a1 = BN_CTX_get(ctx);
  	a2 = BN_CTX_get(ctx);
  	a3 = BN_CTX_get(ctx);
  	b1 = BN_CTX_get(ctx);
  	b2 = BN_CTX_get(ctx);
  	b3 = BN_CTX_get(ctx);
  	if (!b3)
  		{
  		BN_CTX_end(ctx);
  		if (ctx_new)
  			BN_CTX_free(ctx);
  		return -1;
  		}
  
  	/* XXX This approach assumes that the external representation
  	 * of curves over the same field type is the same.
  	 */
  	if (!a->meth->group_get_curve(a, a1, a2, a3, ctx) ||
  	    !b->meth->group_get_curve(b, b1, b2, b3, ctx))
  		r = 1;
  
  	if (r || BN_cmp(a1, b1) || BN_cmp(a2, b2) || BN_cmp(a3, b3))
  		r = 1;
  
  	/* XXX EC_POINT_cmp() assumes that the methods are equal */
  	if (r || EC_POINT_cmp(a, EC_GROUP_get0_generator(a),
  	    EC_GROUP_get0_generator(b), ctx))
  		r = 1;
  
  	if (!r)
  		{
  		/* compare the order and cofactor */
  		if (!EC_GROUP_get_order(a, a1, ctx) ||
  		    !EC_GROUP_get_order(b, b1, ctx) ||
  		    !EC_GROUP_get_cofactor(a, a2, ctx) ||
  		    !EC_GROUP_get_cofactor(b, b2, ctx))
  			{
  			BN_CTX_end(ctx);
  			if (ctx_new)
  				BN_CTX_free(ctx);
  			return -1;
  			}
  		if (BN_cmp(a1, b1) || BN_cmp(a2, b2))
  			r = 1;
  		}
  
  	BN_CTX_end(ctx);
  	if (ctx_new)
  		BN_CTX_free(ctx);
  
  	return r;
  	}
  
  
  /* this has 'package' visibility */
  int EC_EX_DATA_set_data(EC_EXTRA_DATA **ex_data, void *data,
  	void *(*dup_func)(void *), void (*free_func)(void *), void (*clear_free_func)(void *))
  	{
  	EC_EXTRA_DATA *d;
  
  	if (ex_data == NULL)
  		return 0;
  
  	for (d = *ex_data; d != NULL; d = d->next)
  		{
  		if (d->dup_func == dup_func && d->free_func == free_func && d->clear_free_func == clear_free_func)
  			{
  			ECerr(EC_F_EC_EX_DATA_SET_DATA, EC_R_SLOT_FULL);
  			return 0;
  			}
  		}
  
  	if (data == NULL)
  		/* no explicit entry needed */
  		return 1;
  
  	d = OPENSSL_malloc(sizeof *d);
  	if (d == NULL)
  		return 0;
  
  	d->data = data;
  	d->dup_func = dup_func;
  	d->free_func = free_func;
  	d->clear_free_func = clear_free_func;
  
  	d->next = *ex_data;
  	*ex_data = d;
  
  	return 1;
  	}
  
  /* this has 'package' visibility */
  void *EC_EX_DATA_get_data(const EC_EXTRA_DATA *ex_data,
  	void *(*dup_func)(void *), void (*free_func)(void *), void (*clear_free_func)(void *))
  	{
  	const EC_EXTRA_DATA *d;
  
  	for (d = ex_data; d != NULL; d = d->next)
  		{
  		if (d->dup_func == dup_func && d->free_func == free_func && d->clear_free_func == clear_free_func)
  			return d->data;
  		}
  	
  	return NULL;
  	}
  
  /* this has 'package' visibility */
  void EC_EX_DATA_free_data(EC_EXTRA_DATA **ex_data,
  	void *(*dup_func)(void *), void (*free_func)(void *), void (*clear_free_func)(void *))
  	{
  	EC_EXTRA_DATA **p;
  
  	if (ex_data == NULL)
  		return;
  
  	for (p = ex_data; *p != NULL; p = &((*p)->next))
  		{
  		if ((*p)->dup_func == dup_func && (*p)->free_func == free_func && (*p)->clear_free_func == clear_free_func)
  			{
  			EC_EXTRA_DATA *next = (*p)->next;
  
  			(*p)->free_func((*p)->data);
  			OPENSSL_free(*p);
  			
  			*p = next;
  			return;
  			}
  		}
  	}
  
  /* this has 'package' visibility */
  void EC_EX_DATA_clear_free_data(EC_EXTRA_DATA **ex_data,
  	void *(*dup_func)(void *), void (*free_func)(void *), void (*clear_free_func)(void *))
  	{
  	EC_EXTRA_DATA **p;
  
  	if (ex_data == NULL)
  		return;
  
  	for (p = ex_data; *p != NULL; p = &((*p)->next))
  		{
  		if ((*p)->dup_func == dup_func && (*p)->free_func == free_func && (*p)->clear_free_func == clear_free_func)
  			{
  			EC_EXTRA_DATA *next = (*p)->next;
  
  			(*p)->clear_free_func((*p)->data);
  			OPENSSL_free(*p);
  			
  			*p = next;
  			return;
  			}
  		}
  	}
  
  /* this has 'package' visibility */
  void EC_EX_DATA_free_all_data(EC_EXTRA_DATA **ex_data)
  	{
  	EC_EXTRA_DATA *d;
  
  	if (ex_data == NULL)
  		return;
  
  	d = *ex_data;
  	while (d)
  		{
  		EC_EXTRA_DATA *next = d->next;
  		
  		d->free_func(d->data);
  		OPENSSL_free(d);
  		
  		d = next;
  		}
  	*ex_data = NULL;
  	}
  
  /* this has 'package' visibility */
  void EC_EX_DATA_clear_free_all_data(EC_EXTRA_DATA **ex_data)
  	{
  	EC_EXTRA_DATA *d;
  
  	if (ex_data == NULL)
  		return;
  
  	d = *ex_data;
  	while (d)
  		{
  		EC_EXTRA_DATA *next = d->next;
  		
  		d->clear_free_func(d->data);
  		OPENSSL_free(d);
  		
  		d = next;
  		}
  	*ex_data = NULL;
  	}
  
  
  /* functions for EC_POINT objects */
  
  EC_POINT *EC_POINT_new(const EC_GROUP *group)
  	{
  	EC_POINT *ret;
  
  	if (group == NULL)
  		{
  		ECerr(EC_F_EC_POINT_NEW, ERR_R_PASSED_NULL_PARAMETER);
  		return NULL;
  		}
  	if (group->meth->point_init == 0)
  		{
  		ECerr(EC_F_EC_POINT_NEW, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
  		return NULL;
  		}
  
  	ret = OPENSSL_malloc(sizeof *ret);
  	if (ret == NULL)
  		{
  		ECerr(EC_F_EC_POINT_NEW, ERR_R_MALLOC_FAILURE);
  		return NULL;
  		}
  
  	ret->meth = group->meth;
  	
  	if (!ret->meth->point_init(ret))
  		{
  		OPENSSL_free(ret);
  		return NULL;
  		}
  	
  	return ret;
  	}
  
  
  void EC_POINT_free(EC_POINT *point)
  	{
  	if (!point) return;
  
  	if (point->meth->point_finish != 0)
  		point->meth->point_finish(point);
  	OPENSSL_free(point);
  	}
   
  
  void EC_POINT_clear_free(EC_POINT *point)
  	{
  	if (!point) return;
  
  	if (point->meth->point_clear_finish != 0)
  		point->meth->point_clear_finish(point);
  	else if (point->meth->point_finish != 0)
  		point->meth->point_finish(point);
  	OPENSSL_cleanse(point, sizeof *point);
  	OPENSSL_free(point);
  	}
  
  
  int EC_POINT_copy(EC_POINT *dest, const EC_POINT *src)
  	{
  	if (dest->meth->point_copy == 0)
  		{
  		ECerr(EC_F_EC_POINT_COPY, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
  		return 0;
  		}
  	if (dest->meth != src->meth)
  		{
  		ECerr(EC_F_EC_POINT_COPY, EC_R_INCOMPATIBLE_OBJECTS);
  		return 0;
  		}
  	if (dest == src)
  		return 1;
  	return dest->meth->point_copy(dest, src);
  	}
  
  
  EC_POINT *EC_POINT_dup(const EC_POINT *a, const EC_GROUP *group)
  	{
  	EC_POINT *t;
  	int r;
  
  	if (a == NULL) return NULL;
  
  	t = EC_POINT_new(group);
  	if (t == NULL) return(NULL);
  	r = EC_POINT_copy(t, a);
  	if (!r)
  		{
  		EC_POINT_free(t);
  		return NULL;
  		}
  	else return t;
  	}
  
  
  const EC_METHOD *EC_POINT_method_of(const EC_POINT *point)
  	{
  	return point->meth;
  	}
  
  
  int EC_POINT_set_to_infinity(const EC_GROUP *group, EC_POINT *point)
  	{
  	if (group->meth->point_set_to_infinity == 0)
  		{
  		ECerr(EC_F_EC_POINT_SET_TO_INFINITY, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
  		return 0;
  		}
  	if (group->meth != point->meth)
  		{
  		ECerr(EC_F_EC_POINT_SET_TO_INFINITY, EC_R_INCOMPATIBLE_OBJECTS);
  		return 0;
  		}
  	return group->meth->point_set_to_infinity(group, point);
  	}
  
  
  int EC_POINT_set_Jprojective_coordinates_GFp(const EC_GROUP *group, EC_POINT *point,
  	const BIGNUM *x, const BIGNUM *y, const BIGNUM *z, BN_CTX *ctx)
  	{
  	if (group->meth->point_set_Jprojective_coordinates_GFp == 0)
  		{
  		ECerr(EC_F_EC_POINT_SET_JPROJECTIVE_COORDINATES_GFP, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
  		return 0;
  		}
  	if (group->meth != point->meth)
  		{
  		ECerr(EC_F_EC_POINT_SET_JPROJECTIVE_COORDINATES_GFP, EC_R_INCOMPATIBLE_OBJECTS);
  		return 0;
  		}
  	return group->meth->point_set_Jprojective_coordinates_GFp(group, point, x, y, z, ctx);
  	}
  
  
  int EC_POINT_get_Jprojective_coordinates_GFp(const EC_GROUP *group, const EC_POINT *point,
  	BIGNUM *x, BIGNUM *y, BIGNUM *z, BN_CTX *ctx)
  	{
  	if (group->meth->point_get_Jprojective_coordinates_GFp == 0)
  		{
  		ECerr(EC_F_EC_POINT_GET_JPROJECTIVE_COORDINATES_GFP, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
  		return 0;
  		}
  	if (group->meth != point->meth)
  		{
  		ECerr(EC_F_EC_POINT_GET_JPROJECTIVE_COORDINATES_GFP, EC_R_INCOMPATIBLE_OBJECTS);
  		return 0;
  		}
  	return group->meth->point_get_Jprojective_coordinates_GFp(group, point, x, y, z, ctx);
  	}
  
  
  int EC_POINT_set_affine_coordinates_GFp(const EC_GROUP *group, EC_POINT *point,
  	const BIGNUM *x, const BIGNUM *y, BN_CTX *ctx)
  	{
  	if (group->meth->point_set_affine_coordinates == 0)
  		{
  		ECerr(EC_F_EC_POINT_SET_AFFINE_COORDINATES_GFP, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
  		return 0;
  		}
  	if (group->meth != point->meth)
  		{
  		ECerr(EC_F_EC_POINT_SET_AFFINE_COORDINATES_GFP, EC_R_INCOMPATIBLE_OBJECTS);
  		return 0;
  		}
  	return group->meth->point_set_affine_coordinates(group, point, x, y, ctx);
  	}
  
  #ifndef OPENSSL_NO_EC2M
  int EC_POINT_set_affine_coordinates_GF2m(const EC_GROUP *group, EC_POINT *point,
  	const BIGNUM *x, const BIGNUM *y, BN_CTX *ctx)
  	{
  	if (group->meth->point_set_affine_coordinates == 0)
  		{
  		ECerr(EC_F_EC_POINT_SET_AFFINE_COORDINATES_GF2M, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
  		return 0;
  		}
  	if (group->meth != point->meth)
  		{
  		ECerr(EC_F_EC_POINT_SET_AFFINE_COORDINATES_GF2M, EC_R_INCOMPATIBLE_OBJECTS);
  		return 0;
  		}
  	return group->meth->point_set_affine_coordinates(group, point, x, y, ctx);
  	}
  #endif
  
  int EC_POINT_get_affine_coordinates_GFp(const EC_GROUP *group, const EC_POINT *point,
  	BIGNUM *x, BIGNUM *y, BN_CTX *ctx)
  	{
  	if (group->meth->point_get_affine_coordinates == 0)
  		{
  		ECerr(EC_F_EC_POINT_GET_AFFINE_COORDINATES_GFP, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
  		return 0;
  		}
  	if (group->meth != point->meth)
  		{
  		ECerr(EC_F_EC_POINT_GET_AFFINE_COORDINATES_GFP, EC_R_INCOMPATIBLE_OBJECTS);
  		return 0;
  		}
  	return group->meth->point_get_affine_coordinates(group, point, x, y, ctx);
  	}
  
  #ifndef OPENSSL_NO_EC2M
  int EC_POINT_get_affine_coordinates_GF2m(const EC_GROUP *group, const EC_POINT *point,
  	BIGNUM *x, BIGNUM *y, BN_CTX *ctx)
  	{
  	if (group->meth->point_get_affine_coordinates == 0)
  		{
  		ECerr(EC_F_EC_POINT_GET_AFFINE_COORDINATES_GF2M, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
  		return 0;
  		}
  	if (group->meth != point->meth)
  		{
  		ECerr(EC_F_EC_POINT_GET_AFFINE_COORDINATES_GF2M, EC_R_INCOMPATIBLE_OBJECTS);
  		return 0;
  		}
  	return group->meth->point_get_affine_coordinates(group, point, x, y, ctx);
  	}
  #endif
  
  int EC_POINT_add(const EC_GROUP *group, EC_POINT *r, const EC_POINT *a, const EC_POINT *b, BN_CTX *ctx)
  	{
  	if (group->meth->add == 0)
  		{
  		ECerr(EC_F_EC_POINT_ADD, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
  		return 0;
  		}
  	if ((group->meth != r->meth) || (r->meth != a->meth) || (a->meth != b->meth))
  		{
  		ECerr(EC_F_EC_POINT_ADD, EC_R_INCOMPATIBLE_OBJECTS);
  		return 0;
  		}
  	return group->meth->add(group, r, a, b, ctx);
  	}
  
  
  int EC_POINT_dbl(const EC_GROUP *group, EC_POINT *r, const EC_POINT *a, BN_CTX *ctx)
  	{
  	if (group->meth->dbl == 0)
  		{
  		ECerr(EC_F_EC_POINT_DBL, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
  		return 0;
  		}
  	if ((group->meth != r->meth) || (r->meth != a->meth))
  		{
  		ECerr(EC_F_EC_POINT_DBL, EC_R_INCOMPATIBLE_OBJECTS);
  		return 0;
  		}
  	return group->meth->dbl(group, r, a, ctx);
  	}
  
  
  int EC_POINT_invert(const EC_GROUP *group, EC_POINT *a, BN_CTX *ctx)
  	{
  	if (group->meth->dbl == 0)
  		{
  		ECerr(EC_F_EC_POINT_INVERT, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
  		return 0;
  		}
  	if (group->meth != a->meth)
  		{
  		ECerr(EC_F_EC_POINT_INVERT, EC_R_INCOMPATIBLE_OBJECTS);
  		return 0;
  		}
  	return group->meth->invert(group, a, ctx);
  	}
  
  
  int EC_POINT_is_at_infinity(const EC_GROUP *group, const EC_POINT *point)
  	{
  	if (group->meth->is_at_infinity == 0)
  		{
  		ECerr(EC_F_EC_POINT_IS_AT_INFINITY, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
  		return 0;
  		}
  	if (group->meth != point->meth)
  		{
  		ECerr(EC_F_EC_POINT_IS_AT_INFINITY, EC_R_INCOMPATIBLE_OBJECTS);
  		return 0;
  		}
  	return group->meth->is_at_infinity(group, point);
  	}
  
  
  int EC_POINT_is_on_curve(const EC_GROUP *group, const EC_POINT *point, BN_CTX *ctx)
  	{
  	if (group->meth->is_on_curve == 0)
  		{
  		ECerr(EC_F_EC_POINT_IS_ON_CURVE, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
  		return 0;
  		}
  	if (group->meth != point->meth)
  		{
  		ECerr(EC_F_EC_POINT_IS_ON_CURVE, EC_R_INCOMPATIBLE_OBJECTS);
  		return 0;
  		}
  	return group->meth->is_on_curve(group, point, ctx);
  	}
  
  
  int EC_POINT_cmp(const EC_GROUP *group, const EC_POINT *a, const EC_POINT *b, BN_CTX *ctx)
  	{
  	if (group->meth->point_cmp == 0)
  		{
  		ECerr(EC_F_EC_POINT_CMP, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
  		return -1;
  		}
  	if ((group->meth != a->meth) || (a->meth != b->meth))
  		{
  		ECerr(EC_F_EC_POINT_CMP, EC_R_INCOMPATIBLE_OBJECTS);
  		return -1;
  		}
  	return group->meth->point_cmp(group, a, b, ctx);
  	}
  
  
  int EC_POINT_make_affine(const EC_GROUP *group, EC_POINT *point, BN_CTX *ctx)
  	{
  	if (group->meth->make_affine == 0)
  		{
  		ECerr(EC_F_EC_POINT_MAKE_AFFINE, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
  		return 0;
  		}
  	if (group->meth != point->meth)
  		{
  		ECerr(EC_F_EC_POINT_MAKE_AFFINE, EC_R_INCOMPATIBLE_OBJECTS);
  		return 0;
  		}
  	return group->meth->make_affine(group, point, ctx);
  	}
  
  
  int EC_POINTs_make_affine(const EC_GROUP *group, size_t num, EC_POINT *points[], BN_CTX *ctx)
  	{
  	size_t i;
  
  	if (group->meth->points_make_affine == 0)
  		{
  		ECerr(EC_F_EC_POINTS_MAKE_AFFINE, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
  		return 0;
  		}
  	for (i = 0; i < num; i++)
  		{
  		if (group->meth != points[i]->meth)
  			{
  			ECerr(EC_F_EC_POINTS_MAKE_AFFINE, EC_R_INCOMPATIBLE_OBJECTS);
  			return 0;
  			}
  		}
  	return group->meth->points_make_affine(group, num, points, ctx);
  	}
  
  
  /* Functions for point multiplication.
   *
   * If group->meth->mul is 0, we use the wNAF-based implementations in ec_mult.c;
   * otherwise we dispatch through methods.
   */
  
  int EC_POINTs_mul(const EC_GROUP *group, EC_POINT *r, const BIGNUM *scalar,
  	size_t num, const EC_POINT *points[], const BIGNUM *scalars[], BN_CTX *ctx)
  	{
  	if (group->meth->mul == 0)
  		/* use default */
  		return ec_wNAF_mul(group, r, scalar, num, points, scalars, ctx);
  
  	return group->meth->mul(group, r, scalar, num, points, scalars, ctx);
  	}
  
  int EC_POINT_mul(const EC_GROUP *group, EC_POINT *r, const BIGNUM *g_scalar,
  	const EC_POINT *point, const BIGNUM *p_scalar, BN_CTX *ctx)
  	{
  	/* just a convenient interface to EC_POINTs_mul() */
  
  	const EC_POINT *points[1];
  	const BIGNUM *scalars[1];
  
  	points[0] = point;
  	scalars[0] = p_scalar;
  
  	return EC_POINTs_mul(group, r, g_scalar, (point != NULL && p_scalar != NULL), points, scalars, ctx);
  	}
  
  int EC_GROUP_precompute_mult(EC_GROUP *group, BN_CTX *ctx)
  	{
  	if (group->meth->mul == 0)
  		/* use default */
  		return ec_wNAF_precompute_mult(group, ctx);
  
  	if (group->meth->precompute_mult != 0)
  		return group->meth->precompute_mult(group, ctx);
  	else
  		return 1; /* nothing to do, so report success */
  	}
  
  int EC_GROUP_have_precompute_mult(const EC_GROUP *group)
  	{
  	if (group->meth->mul == 0)
  		/* use default */
  		return ec_wNAF_have_precompute_mult(group);
  
  	if (group->meth->have_precompute_mult != 0)
  		return group->meth->have_precompute_mult(group);
  	else
  		return 0; /* cannot tell whether precomputation has been performed */
  	}
  