libcrypto/ec/ec_lib.c

/* $OpenBSD: ec_lib.c,v 1.22 2016/09/03 12:10:40 beck Exp $ */
/*
 * 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/opensslconf.h>

#include <openssl/err.h>
#include <openssl/opensslv.h>

#include "ec_lcl.h"

/* 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 = 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)) {
		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);

	EC_POINT_free(group->generator);
	BN_free(&group->order);
	BN_free(&group->cofactor);

	free(group->seed);

	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);

	EC_POINT_clear_free(group->generator);
	BN_clear_free(&group->order);
	BN_clear_free(&group->cofactor);

	if (group->seed) {
		explicit_bzero(group->seed, group->seed_len);
		free(group->seed);
	}
	explicit_bzero(group, sizeof *group);
	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 */
		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) {
		free(dest->seed);
		dest->seed = malloc(src->seed_len);
		if (dest->seed == NULL)
			return 0;
		memcpy(dest->seed, src->seed, src->seed_len);
		dest->seed_len = src->seed_len;
	} else {
		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;

	if ((a != NULL) && ((t = EC_GROUP_new(a->meth)) != NULL) &&
	    (!EC_GROUP_copy(t, a))) {
		EC_GROUP_free(t);
		t = NULL;
	}
	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) {
		free(group->seed);
		group->seed = NULL;
		group->seed_len = 0;
	}
	if (!len || !p)
		return 1;

	if ((group->seed = 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);
	if ((a1 = BN_CTX_get(ctx)) == NULL)
		goto err;
	if ((a2 = BN_CTX_get(ctx)) == NULL)
		goto err;
	if ((a3 = BN_CTX_get(ctx)) == NULL)
		goto err;
	if ((b1 = BN_CTX_get(ctx)) == NULL)
		goto err;
	if ((b2 = BN_CTX_get(ctx)) == NULL)
		goto err;
	if ((b3 = BN_CTX_get(ctx)) == NULL)
		goto err;

	/*
	 * 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))
			goto err;
		if (BN_cmp(a1, b1) || BN_cmp(a2, b2))
			r = 1;
	}
	BN_CTX_end(ctx);
	if (ctx_new)
		BN_CTX_free(ctx);

	return r;

err:
	BN_CTX_end(ctx);
	if (ctx_new)
		BN_CTX_free(ctx);
	return -1;
}


/* 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 = 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);
			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);
			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);
		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);
		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 = 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)) {
		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);
	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);
	explicit_bzero(point, sizeof *point);
	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->invert == 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 */
}

EC_KEY *
ECParameters_dup(EC_KEY *key)
{
	unsigned char *p = NULL;
	EC_KEY *k = NULL;
	int len;

	if (key == NULL)
		return (NULL);

	if ((len = i2d_ECParameters(key, &p)) > 0)
		k = d2i_ECParameters(NULL, (const unsigned char **)&p, len);

	return (k);
}