svn merge ^/branches/released .

1 files changed, 1042 insertions, 1039 deletions

diff --git a/openssl/crypto/ec/ec2_smpl.c b/openssl/crypto/ec/ec2_smpl.c
index cf357b462..1725dd128 100644
--- a/openssl/crypto/ec/ec2_smpl.c
+++ b/openssl/crypto/ec/ec2_smpl.c
@@ -1,1039 +1,1042 @@
-/* crypto/ec/ec2_smpl.c */
-/* ====================================================================
- * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
- *
- * The Elliptic Curve Public-Key Crypto Library (ECC Code) included
- * herein is developed by SUN MICROSYSTEMS, INC., and is contributed
- * to the OpenSSL project.
- *
- * The ECC Code is licensed pursuant to the OpenSSL open source
- * license provided below.
- *
- * The software is originally written by Sheueling Chang Shantz and
- * Douglas Stebila of Sun Microsystems Laboratories.
- *
- */
-/* ====================================================================
- * 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).
- *
- */
-
-#include <openssl/err.h>
-
-#include "ec_lcl.h"
-
-
-const EC_METHOD *EC_GF2m_simple_method(void)
-	{
-	static const EC_METHOD ret = {
-		NID_X9_62_characteristic_two_field,
-		ec_GF2m_simple_group_init,
-		ec_GF2m_simple_group_finish,
-		ec_GF2m_simple_group_clear_finish,
-		ec_GF2m_simple_group_copy,
-		ec_GF2m_simple_group_set_curve,
-		ec_GF2m_simple_group_get_curve,
-		ec_GF2m_simple_group_get_degree,
-		ec_GF2m_simple_group_check_discriminant,
-		ec_GF2m_simple_point_init,
-		ec_GF2m_simple_point_finish,
-		ec_GF2m_simple_point_clear_finish,
-		ec_GF2m_simple_point_copy,
-		ec_GF2m_simple_point_set_to_infinity,
-		0 /* set_Jprojective_coordinates_GFp */,
-		0 /* get_Jprojective_coordinates_GFp */,
-		ec_GF2m_simple_point_set_affine_coordinates,
-		ec_GF2m_simple_point_get_affine_coordinates,
-		ec_GF2m_simple_set_compressed_coordinates,
-		ec_GF2m_simple_point2oct,
-		ec_GF2m_simple_oct2point,
-		ec_GF2m_simple_add,
-		ec_GF2m_simple_dbl,
-		ec_GF2m_simple_invert,
-		ec_GF2m_simple_is_at_infinity,
-		ec_GF2m_simple_is_on_curve,
-		ec_GF2m_simple_cmp,
-		ec_GF2m_simple_make_affine,
-		ec_GF2m_simple_points_make_affine,
-
-		/* the following three method functions are defined in ec2_mult.c */
-		ec_GF2m_simple_mul,
-		ec_GF2m_precompute_mult,
-		ec_GF2m_have_precompute_mult,
-
-		ec_GF2m_simple_field_mul,
-		ec_GF2m_simple_field_sqr,
-		ec_GF2m_simple_field_div,
-		0 /* field_encode */,
-		0 /* field_decode */,
-		0 /* field_set_to_one */ };
-
-	return &ret;
-	}
-
-
-/* Initialize a GF(2^m)-based EC_GROUP structure.
- * Note that all other members are handled by EC_GROUP_new.
- */
-int ec_GF2m_simple_group_init(EC_GROUP *group)
-	{
-	BN_init(&group->field);
-	BN_init(&group->a);
-	BN_init(&group->b);
-	return 1;
-	}
-
-
-/* Free a GF(2^m)-based EC_GROUP structure.
- * Note that all other members are handled by EC_GROUP_free.
- */
-void ec_GF2m_simple_group_finish(EC_GROUP *group)
-	{
-	BN_free(&group->field);
-	BN_free(&group->a);
-	BN_free(&group->b);
-	}
-
-
-/* Clear and free a GF(2^m)-based EC_GROUP structure.
- * Note that all other members are handled by EC_GROUP_clear_free.
- */
-void ec_GF2m_simple_group_clear_finish(EC_GROUP *group)
-	{
-	BN_clear_free(&group->field);
-	BN_clear_free(&group->a);
-	BN_clear_free(&group->b);
-	group->poly[0] = 0;
-	group->poly[1] = 0;
-	group->poly[2] = 0;
-	group->poly[3] = 0;
-	group->poly[4] = 0;
-	group->poly[5] = -1;
-	}
-
-
-/* Copy a GF(2^m)-based EC_GROUP structure.
- * Note that all other members are handled by EC_GROUP_copy.
- */
-int ec_GF2m_simple_group_copy(EC_GROUP *dest, const EC_GROUP *src)
-	{
-	int i;
-	if (!BN_copy(&dest->field, &src->field)) return 0;
-	if (!BN_copy(&dest->a, &src->a)) return 0;
-	if (!BN_copy(&dest->b, &src->b)) return 0;
-	dest->poly[0] = src->poly[0];
-	dest->poly[1] = src->poly[1];
-	dest->poly[2] = src->poly[2];
-	dest->poly[3] = src->poly[3];
-	dest->poly[4] = src->poly[4];
-	dest->poly[5] = src->poly[5];
-	if (bn_wexpand(&dest->a, (int)(dest->poly[0] + BN_BITS2 - 1) / BN_BITS2) == NULL) return 0;
-	if (bn_wexpand(&dest->b, (int)(dest->poly[0] + BN_BITS2 - 1) / BN_BITS2) == NULL) return 0;
-	for (i = dest->a.top; i < dest->a.dmax; i++) dest->a.d[i] = 0;
-	for (i = dest->b.top; i < dest->b.dmax; i++) dest->b.d[i] = 0;
-	return 1;
-	}
-
-
-/* Set the curve parameters of an EC_GROUP structure. */
-int ec_GF2m_simple_group_set_curve(EC_GROUP *group,
-	const BIGNUM *p, const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx)
-	{
-	int ret = 0, i;
-
-	/* group->field */
-	if (!BN_copy(&group->field, p)) goto err;
-	i = BN_GF2m_poly2arr(&group->field, group->poly, 6) - 1;
-	if ((i != 5) && (i != 3))
-		{
-		ECerr(EC_F_EC_GF2M_SIMPLE_GROUP_SET_CURVE, EC_R_UNSUPPORTED_FIELD);
-		goto err;
-		}
-
-	/* group->a */
-	if (!BN_GF2m_mod_arr(&group->a, a, group->poly)) goto err;
-	if(bn_wexpand(&group->a, (int)(group->poly[0] + BN_BITS2 - 1) / BN_BITS2) == NULL) goto err;
-	for (i = group->a.top; i < group->a.dmax; i++) group->a.d[i] = 0;
-	
-	/* group->b */
-	if (!BN_GF2m_mod_arr(&group->b, b, group->poly)) goto err;
-	if(bn_wexpand(&group->b, (int)(group->poly[0] + BN_BITS2 - 1) / BN_BITS2) == NULL) goto err;
-	for (i = group->b.top; i < group->b.dmax; i++) group->b.d[i] = 0;
-		
-	ret = 1;
-  err:
-	return ret;
-	}
-
-
-/* Get the curve parameters of an EC_GROUP structure.
- * If p, a, or b are NULL then there values will not be set but the method will return with success.
- */
-int ec_GF2m_simple_group_get_curve(const EC_GROUP *group, BIGNUM *p, BIGNUM *a, BIGNUM *b, BN_CTX *ctx)
-	{
-	int ret = 0;
-	
-	if (p != NULL)
-		{
-		if (!BN_copy(p, &group->field)) return 0;
-		}
-
-	if (a != NULL)
-		{
-		if (!BN_copy(a, &group->a)) goto err;
-		}
-
-	if (b != NULL)
-		{
-		if (!BN_copy(b, &group->b)) goto err;
-		}
-	
-	ret = 1;
-	
-  err:
-	return ret;
-	}
-
-
-/* Gets the degree of the field.  For a curve over GF(2^m) this is the value m. */
-int ec_GF2m_simple_group_get_degree(const EC_GROUP *group)
-	{
-	return BN_num_bits(&group->field)-1;
-	}
-
-
-/* Checks the discriminant of the curve.
- * y^2 + x*y = x^3 + a*x^2 + b is an elliptic curve <=> b != 0 (mod p) 
- */
-int ec_GF2m_simple_group_check_discriminant(const EC_GROUP *group, BN_CTX *ctx)
-	{
-	int ret = 0;
-	BIGNUM *b;
-	BN_CTX *new_ctx = NULL;
-
-	if (ctx == NULL)
-		{
-		ctx = new_ctx = BN_CTX_new();
-		if (ctx == NULL)
-			{
-			ECerr(EC_F_EC_GF2M_SIMPLE_GROUP_CHECK_DISCRIMINANT, ERR_R_MALLOC_FAILURE);
-			goto err;
-			}
-		}
-	BN_CTX_start(ctx);
-	b = BN_CTX_get(ctx);
-	if (b == NULL) goto err;
-
-	if (!BN_GF2m_mod_arr(b, &group->b, group->poly)) goto err;
-	
-	/* check the discriminant:
-	 * y^2 + x*y = x^3 + a*x^2 + b is an elliptic curve <=> b != 0 (mod p) 
-	 */
-	if (BN_is_zero(b)) goto err;
-
-	ret = 1;
-
-err:
-	if (ctx != NULL)
-		BN_CTX_end(ctx);
-	if (new_ctx != NULL)
-		BN_CTX_free(new_ctx);
-	return ret;
-	}
-
-
-/* Initializes an EC_POINT. */
-int ec_GF2m_simple_point_init(EC_POINT *point)
-	{
-	BN_init(&point->X);
-	BN_init(&point->Y);
-	BN_init(&point->Z);
-	return 1;
-	}
-
-
-/* Frees an EC_POINT. */
-void ec_GF2m_simple_point_finish(EC_POINT *point)
-	{
-	BN_free(&point->X);
-	BN_free(&point->Y);
-	BN_free(&point->Z);
-	}
-
-
-/* Clears and frees an EC_POINT. */
-void ec_GF2m_simple_point_clear_finish(EC_POINT *point)
-	{
-	BN_clear_free(&point->X);
-	BN_clear_free(&point->Y);
-	BN_clear_free(&point->Z);
-	point->Z_is_one = 0;
-	}
-
-
-/* Copy the contents of one EC_POINT into another.  Assumes dest is initialized. */
-int ec_GF2m_simple_point_copy(EC_POINT *dest, const EC_POINT *src)
-	{
-	if (!BN_copy(&dest->X, &src->X)) return 0;
-	if (!BN_copy(&dest->Y, &src->Y)) return 0;
-	if (!BN_copy(&dest->Z, &src->Z)) return 0;
-	dest->Z_is_one = src->Z_is_one;
-
-	return 1;
-	}
-
-
-/* Set an EC_POINT to the point at infinity.  
- * A point at infinity is represented by having Z=0.
- */
-int ec_GF2m_simple_point_set_to_infinity(const EC_GROUP *group, EC_POINT *point)
-	{
-	point->Z_is_one = 0;
-	BN_zero(&point->Z);
-	return 1;
-	}
-
-
-/* Set the coordinates of an EC_POINT using affine coordinates. 
- * Note that the simple implementation only uses affine coordinates.
- */
-int ec_GF2m_simple_point_set_affine_coordinates(const EC_GROUP *group, EC_POINT *point,
-	const BIGNUM *x, const BIGNUM *y, BN_CTX *ctx)
-	{
-	int ret = 0;	
-	if (x == NULL || y == NULL)
-		{
-		ECerr(EC_F_EC_GF2M_SIMPLE_POINT_SET_AFFINE_COORDINATES, ERR_R_PASSED_NULL_PARAMETER);
-		return 0;
-		}
-
-	if (!BN_copy(&point->X, x)) goto err;
-	BN_set_negative(&point->X, 0);
-	if (!BN_copy(&point->Y, y)) goto err;
-	BN_set_negative(&point->Y, 0);
-	if (!BN_copy(&point->Z, BN_value_one())) goto err;
-	BN_set_negative(&point->Z, 0);
-	point->Z_is_one = 1;
-	ret = 1;
-
-  err:
-	return ret;
-	}
-
-
-/* Gets the affine coordinates of an EC_POINT. 
- * Note that the simple implementation only uses affine coordinates.
- */
-int ec_GF2m_simple_point_get_affine_coordinates(const EC_GROUP *group, const EC_POINT *point,
-	BIGNUM *x, BIGNUM *y, BN_CTX *ctx)
-	{
-	int ret = 0;
-
-	if (EC_POINT_is_at_infinity(group, point))
-		{
-		ECerr(EC_F_EC_GF2M_SIMPLE_POINT_GET_AFFINE_COORDINATES, EC_R_POINT_AT_INFINITY);
-		return 0;
-		}
-
-	if (BN_cmp(&point->Z, BN_value_one())) 
-		{
-		ECerr(EC_F_EC_GF2M_SIMPLE_POINT_GET_AFFINE_COORDINATES, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
-		return 0;
-		}
-	if (x != NULL)
-		{
-		if (!BN_copy(x, &point->X)) goto err;
-		BN_set_negative(x, 0);
-		}
-	if (y != NULL)
-		{
-		if (!BN_copy(y, &point->Y)) goto err;
-		BN_set_negative(y, 0);
-		}
-	ret = 1;
-		
- err:
-	return ret;
-	}
-
-
-/* Calculates and sets the affine coordinates of an EC_POINT from the given
- * compressed coordinates.  Uses algorithm 2.3.4 of SEC 1. 
- * Note that the simple implementation only uses affine coordinates.
- *
- * The method is from the following publication:
- * 
- *     Harper, Menezes, Vanstone:
- *     "Public-Key Cryptosystems with Very Small Key Lengths",
- *     EUROCRYPT '92, Springer-Verlag LNCS 658,
- *     published February 1993
- *
- * US Patents 6,141,420 and 6,618,483 (Vanstone, Mullin, Agnew) describe
- * the same method, but claim no priority date earlier than July 29, 1994
- * (and additionally fail to cite the EUROCRYPT '92 publication as prior art).
- */
-int ec_GF2m_simple_set_compressed_coordinates(const EC_GROUP *group, EC_POINT *point,
-	const BIGNUM *x_, int y_bit, BN_CTX *ctx)
-	{
-	BN_CTX *new_ctx = NULL;
-	BIGNUM *tmp, *x, *y, *z;
-	int ret = 0, z0;
-
-	/* clear error queue */
-	ERR_clear_error();
-
-	if (ctx == NULL)
-		{
-		ctx = new_ctx = BN_CTX_new();
-		if (ctx == NULL)
-			return 0;
-		}
-
-	y_bit = (y_bit != 0) ? 1 : 0;
-
-	BN_CTX_start(ctx);
-	tmp = BN_CTX_get(ctx);
-	x = BN_CTX_get(ctx);
-	y = BN_CTX_get(ctx);
-	z = BN_CTX_get(ctx);
-	if (z == NULL) goto err;
-
-	if (!BN_GF2m_mod_arr(x, x_, group->poly)) goto err;
-	if (BN_is_zero(x))
-		{
-		if (!BN_GF2m_mod_sqrt_arr(y, &group->b, group->poly, ctx)) goto err;
-		}
-	else
-		{
-		if (!group->meth->field_sqr(group, tmp, x, ctx)) goto err;
-		if (!group->meth->field_div(group, tmp, &group->b, tmp, ctx)) goto err;
-		if (!BN_GF2m_add(tmp, &group->a, tmp)) goto err;
-		if (!BN_GF2m_add(tmp, x, tmp)) goto err;
-		if (!BN_GF2m_mod_solve_quad_arr(z, tmp, group->poly, ctx))
-			{
-			unsigned long err = ERR_peek_last_error();
-			
-			if (ERR_GET_LIB(err) == ERR_LIB_BN && ERR_GET_REASON(err) == BN_R_NO_SOLUTION)
-				{
-				ERR_clear_error();
-				ECerr(EC_F_EC_GF2M_SIMPLE_SET_COMPRESSED_COORDINATES, EC_R_INVALID_COMPRESSED_POINT);
-				}
-			else
-				ECerr(EC_F_EC_GF2M_SIMPLE_SET_COMPRESSED_COORDINATES, ERR_R_BN_LIB);
-			goto err;
-			}
-		z0 = (BN_is_odd(z)) ? 1 : 0;
-		if (!group->meth->field_mul(group, y, x, z, ctx)) goto err;
-		if (z0 != y_bit)
-			{
-			if (!BN_GF2m_add(y, y, x)) goto err;
-			}
-		}
-
-	if (!EC_POINT_set_affine_coordinates_GF2m(group, point, x, y, ctx)) goto err;
-
-	ret = 1;
-
- err:
-	BN_CTX_end(ctx);
-	if (new_ctx != NULL)
-		BN_CTX_free(new_ctx);
-	return ret;
-	}
-
-
-/* Converts an EC_POINT to an octet string.  
- * If buf is NULL, the encoded length will be returned.
- * If the length len of buf is smaller than required an error will be returned.
- */
-size_t ec_GF2m_simple_point2oct(const EC_GROUP *group, const EC_POINT *point, point_conversion_form_t form,
-	unsigned char *buf, size_t len, BN_CTX *ctx)
-	{
-	size_t ret;
-	BN_CTX *new_ctx = NULL;
-	int used_ctx = 0;
-	BIGNUM *x, *y, *yxi;
-	size_t field_len, i, skip;
-
-	if ((form != POINT_CONVERSION_COMPRESSED)
-		&& (form != POINT_CONVERSION_UNCOMPRESSED)
-		&& (form != POINT_CONVERSION_HYBRID))
-		{
-		ECerr(EC_F_EC_GF2M_SIMPLE_POINT2OCT, EC_R_INVALID_FORM);
-		goto err;
-		}
-
-	if (EC_POINT_is_at_infinity(group, point))
-		{
-		/* encodes to a single 0 octet */
-		if (buf != NULL)
-			{
-			if (len < 1)
-				{
-				ECerr(EC_F_EC_GF2M_SIMPLE_POINT2OCT, EC_R_BUFFER_TOO_SMALL);
-				return 0;
-				}
-			buf[0] = 0;
-			}
-		return 1;
-		}
-
-
-	/* ret := required output buffer length */
-	field_len = (EC_GROUP_get_degree(group) + 7) / 8;
-	ret = (form == POINT_CONVERSION_COMPRESSED) ? 1 + field_len : 1 + 2*field_len;
-
-	/* if 'buf' is NULL, just return required length */
-	if (buf != NULL)
-		{
-		if (len < ret)
-			{
-			ECerr(EC_F_EC_GF2M_SIMPLE_POINT2OCT, EC_R_BUFFER_TOO_SMALL);
-			goto err;
-			}
-
-		if (ctx == NULL)
-			{
-			ctx = new_ctx = BN_CTX_new();
-			if (ctx == NULL)
-				return 0;
-			}
-
-		BN_CTX_start(ctx);
-		used_ctx = 1;
-		x = BN_CTX_get(ctx);
-		y = BN_CTX_get(ctx);
-		yxi = BN_CTX_get(ctx);
-		if (yxi == NULL) goto err;
-
-		if (!EC_POINT_get_affine_coordinates_GF2m(group, point, x, y, ctx)) goto err;
-
-		buf[0] = form;
-		if ((form != POINT_CONVERSION_UNCOMPRESSED) && !BN_is_zero(x))
-			{
-			if (!group->meth->field_div(group, yxi, y, x, ctx)) goto err;
-			if (BN_is_odd(yxi)) buf[0]++;
-			}
-
-		i = 1;
-		
-		skip = field_len - BN_num_bytes(x);
-		if (skip > field_len)
-			{
-			ECerr(EC_F_EC_GF2M_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERROR);
-			goto err;
-			}
-		while (skip > 0)
-			{
-			buf[i++] = 0;
-			skip--;
-			}
-		skip = BN_bn2bin(x, buf + i);
-		i += skip;
-		if (i != 1 + field_len)
-			{
-			ECerr(EC_F_EC_GF2M_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERROR);
-			goto err;
-			}
-
-		if (form == POINT_CONVERSION_UNCOMPRESSED || form == POINT_CONVERSION_HYBRID)
-			{
-			skip = field_len - BN_num_bytes(y);
-			if (skip > field_len)
-				{
-				ECerr(EC_F_EC_GF2M_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERROR);
-				goto err;
-				}
-			while (skip > 0)
-				{
-				buf[i++] = 0;
-				skip--;
-				}
-			skip = BN_bn2bin(y, buf + i);
-			i += skip;
-			}
-
-		if (i != ret)
-			{
-			ECerr(EC_F_EC_GF2M_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERROR);
-			goto err;
-			}
-		}
-	
-	if (used_ctx)
-		BN_CTX_end(ctx);
-	if (new_ctx != NULL)
-		BN_CTX_free(new_ctx);
-	return ret;
-
- err:
-	if (used_ctx)
-		BN_CTX_end(ctx);
-	if (new_ctx != NULL)
-		BN_CTX_free(new_ctx);
-	return 0;
-	}
-
-
-/* Converts an octet string representation to an EC_POINT. 
- * Note that the simple implementation only uses affine coordinates.
- */
-int ec_GF2m_simple_oct2point(const EC_GROUP *group, EC_POINT *point,
-	const unsigned char *buf, size_t len, BN_CTX *ctx)
-	{
-	point_conversion_form_t form;
-	int y_bit;
-	BN_CTX *new_ctx = NULL;
-	BIGNUM *x, *y, *yxi;
-	size_t field_len, enc_len;
-	int ret = 0;
-
-	if (len == 0)
-		{
-		ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_BUFFER_TOO_SMALL);
-		return 0;
-		}
-	form = buf[0];
-	y_bit = form & 1;
-	form = form & ~1U;
-	if ((form != 0)	&& (form != POINT_CONVERSION_COMPRESSED)
-		&& (form != POINT_CONVERSION_UNCOMPRESSED)
-		&& (form != POINT_CONVERSION_HYBRID))
-		{
-		ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
-		return 0;
-		}
-	if ((form == 0 || form == POINT_CONVERSION_UNCOMPRESSED) && y_bit)
-		{
-		ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
-		return 0;
-		}
-
-	if (form == 0)
-		{
-		if (len != 1)
-			{
-			ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
-			return 0;
-			}
-
-		return EC_POINT_set_to_infinity(group, point);
-		}
-	
-	field_len = (EC_GROUP_get_degree(group) + 7) / 8;
-	enc_len = (form == POINT_CONVERSION_COMPRESSED) ? 1 + field_len : 1 + 2*field_len;
-
-	if (len != enc_len)
-		{
-		ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
-		return 0;
-		}
-
-	if (ctx == NULL)
-		{
-		ctx = new_ctx = BN_CTX_new();
-		if (ctx == NULL)
-			return 0;
-		}
-
-	BN_CTX_start(ctx);
-	x = BN_CTX_get(ctx);
-	y = BN_CTX_get(ctx);
-	yxi = BN_CTX_get(ctx);
-	if (yxi == NULL) goto err;
-
-	if (!BN_bin2bn(buf + 1, field_len, x)) goto err;
-	if (BN_ucmp(x, &group->field) >= 0)
-		{
-		ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
-		goto err;
-		}
-
-	if (form == POINT_CONVERSION_COMPRESSED)
-		{
-		if (!EC_POINT_set_compressed_coordinates_GF2m(group, point, x, y_bit, ctx)) goto err;
-		}
-	else
-		{
-		if (!BN_bin2bn(buf + 1 + field_len, field_len, y)) goto err;
-		if (BN_ucmp(y, &group->field) >= 0)
-			{
-			ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
-			goto err;
-			}
-		if (form == POINT_CONVERSION_HYBRID)
-			{
-			if (!group->meth->field_div(group, yxi, y, x, ctx)) goto err;
-			if (y_bit != BN_is_odd(yxi))
-				{
-				ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
-				goto err;
-				}
-			}
-
-		if (!EC_POINT_set_affine_coordinates_GF2m(group, point, x, y, ctx)) goto err;
-		}
-	
-	if (!EC_POINT_is_on_curve(group, point, ctx)) /* test required by X9.62 */
-		{
-		ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_POINT_IS_NOT_ON_CURVE);
-		goto err;
-		}
-
-	ret = 1;
-	
- err:
-	BN_CTX_end(ctx);
-	if (new_ctx != NULL)
-		BN_CTX_free(new_ctx);
-	return ret;
-	}
-
-
-/* Computes a + b and stores the result in r.  r could be a or b, a could be b.
- * Uses algorithm A.10.2 of IEEE P1363.
- */
-int ec_GF2m_simple_add(const EC_GROUP *group, EC_POINT *r, const EC_POINT *a, const EC_POINT *b, BN_CTX *ctx)
-	{
-	BN_CTX *new_ctx = NULL;
-	BIGNUM *x0, *y0, *x1, *y1, *x2, *y2, *s, *t;
-	int ret = 0;
-	
-	if (EC_POINT_is_at_infinity(group, a))
-		{
-		if (!EC_POINT_copy(r, b)) return 0;
-		return 1;
-		}
-
-	if (EC_POINT_is_at_infinity(group, b))
-		{
-		if (!EC_POINT_copy(r, a)) return 0;
-		return 1;
-		}
-
-	if (ctx == NULL)
-		{
-		ctx = new_ctx = BN_CTX_new();
-		if (ctx == NULL)
-			return 0;
-		}
-
-	BN_CTX_start(ctx);
-	x0 = BN_CTX_get(ctx);
-	y0 = BN_CTX_get(ctx);
-	x1 = BN_CTX_get(ctx);
-	y1 = BN_CTX_get(ctx);
-	x2 = BN_CTX_get(ctx);
-	y2 = BN_CTX_get(ctx);
-	s = BN_CTX_get(ctx);
-	t = BN_CTX_get(ctx);
-	if (t == NULL) goto err;
-
-	if (a->Z_is_one) 
-		{
-		if (!BN_copy(x0, &a->X)) goto err;
-		if (!BN_copy(y0, &a->Y)) goto err;
-		}
-	else
-		{
-		if (!EC_POINT_get_affine_coordinates_GF2m(group, a, x0, y0, ctx)) goto err;
-		}
-	if (b->Z_is_one) 
-		{
-		if (!BN_copy(x1, &b->X)) goto err;
-		if (!BN_copy(y1, &b->Y)) goto err;
-		}
-	else
-		{
-		if (!EC_POINT_get_affine_coordinates_GF2m(group, b, x1, y1, ctx)) goto err;
-		}
-
-
-	if (BN_GF2m_cmp(x0, x1))
-		{
-		if (!BN_GF2m_add(t, x0, x1)) goto err;
-		if (!BN_GF2m_add(s, y0, y1)) goto err;
-		if (!group->meth->field_div(group, s, s, t, ctx)) goto err;
-		if (!group->meth->field_sqr(group, x2, s, ctx)) goto err;
-		if (!BN_GF2m_add(x2, x2, &group->a)) goto err;
-		if (!BN_GF2m_add(x2, x2, s)) goto err;
-		if (!BN_GF2m_add(x2, x2, t)) goto err;
-		}
-	else
-		{
-		if (BN_GF2m_cmp(y0, y1) || BN_is_zero(x1))
-			{
-			if (!EC_POINT_set_to_infinity(group, r)) goto err;
-			ret = 1;
-			goto err;
-			}
-		if (!group->meth->field_div(group, s, y1, x1, ctx)) goto err;
-		if (!BN_GF2m_add(s, s, x1)) goto err;
-		
-		if (!group->meth->field_sqr(group, x2, s, ctx)) goto err;
-		if (!BN_GF2m_add(x2, x2, s)) goto err;
-		if (!BN_GF2m_add(x2, x2, &group->a)) goto err;
-		}
-
-	if (!BN_GF2m_add(y2, x1, x2)) goto err;
-	if (!group->meth->field_mul(group, y2, y2, s, ctx)) goto err;
-	if (!BN_GF2m_add(y2, y2, x2)) goto err;
-	if (!BN_GF2m_add(y2, y2, y1)) goto err;
-
-	if (!EC_POINT_set_affine_coordinates_GF2m(group, r, x2, y2, ctx)) goto err;
-
-	ret = 1;
-
- err:
-	BN_CTX_end(ctx);
-	if (new_ctx != NULL)
-		BN_CTX_free(new_ctx);
-	return ret;
-	}
-
-
-/* Computes 2 * a and stores the result in r.  r could be a.
- * Uses algorithm A.10.2 of IEEE P1363.
- */
-int ec_GF2m_simple_dbl(const EC_GROUP *group, EC_POINT *r, const EC_POINT *a, BN_CTX *ctx)
-	{
-	return ec_GF2m_simple_add(group, r, a, a, ctx);
-	}
-
-
-int ec_GF2m_simple_invert(const EC_GROUP *group, EC_POINT *point, BN_CTX *ctx)
-	{
-	if (EC_POINT_is_at_infinity(group, point) || BN_is_zero(&point->Y))
-		/* point is its own inverse */
-		return 1;
-	
-	if (!EC_POINT_make_affine(group, point, ctx)) return 0;
-	return BN_GF2m_add(&point->Y, &point->X, &point->Y);
-	}
-
-
-/* Indicates whether the given point is the point at infinity. */
-int ec_GF2m_simple_is_at_infinity(const EC_GROUP *group, const EC_POINT *point)
-	{
-	return BN_is_zero(&point->Z);
-	}
-
-
-/* Determines whether the given EC_POINT is an actual point on the curve defined
- * in the EC_GROUP.  A point is valid if it satisfies the Weierstrass equation:
- *      y^2 + x*y = x^3 + a*x^2 + b.
- */
-int ec_GF2m_simple_is_on_curve(const EC_GROUP *group, const EC_POINT *point, BN_CTX *ctx)
-	{
-	int ret = -1;
-	BN_CTX *new_ctx = NULL;
-	BIGNUM *lh, *y2;
-	int (*field_mul)(const EC_GROUP *, BIGNUM *, const BIGNUM *, const BIGNUM *, BN_CTX *);
-	int (*field_sqr)(const EC_GROUP *, BIGNUM *, const BIGNUM *, BN_CTX *);
-
-	if (EC_POINT_is_at_infinity(group, point))
-		return 1;
-
-	field_mul = group->meth->field_mul;
-	field_sqr = group->meth->field_sqr;	
-
-	/* only support affine coordinates */
-	if (!point->Z_is_one) goto err;
-
-	if (ctx == NULL)
-		{
-		ctx = new_ctx = BN_CTX_new();
-		if (ctx == NULL)
-			return -1;
-		}
-
-	BN_CTX_start(ctx);
-	y2 = BN_CTX_get(ctx);
-	lh = BN_CTX_get(ctx);
-	if (lh == NULL) goto err;
-
-	/* We have a curve defined by a Weierstrass equation
-	 *      y^2 + x*y = x^3 + a*x^2 + b.
-	 *  <=> x^3 + a*x^2 + x*y + b + y^2 = 0
-	 *  <=> ((x + a) * x + y ) * x + b + y^2 = 0
-	 */
-	if (!BN_GF2m_add(lh, &point->X, &group->a)) goto err;
-	if (!field_mul(group, lh, lh, &point->X, ctx)) goto err;
-	if (!BN_GF2m_add(lh, lh, &point->Y)) goto err;
-	if (!field_mul(group, lh, lh, &point->X, ctx)) goto err;
-	if (!BN_GF2m_add(lh, lh, &group->b)) goto err;
-	if (!field_sqr(group, y2, &point->Y, ctx)) goto err;
-	if (!BN_GF2m_add(lh, lh, y2)) goto err;
-	ret = BN_is_zero(lh);
- err:
-	if (ctx) BN_CTX_end(ctx);
-	if (new_ctx) BN_CTX_free(new_ctx);
-	return ret;
-	}
-
-
-/* Indicates whether two points are equal.
- * Return values:
- *  -1   error
- *   0   equal (in affine coordinates)
- *   1   not equal
- */
-int ec_GF2m_simple_cmp(const EC_GROUP *group, const EC_POINT *a, const EC_POINT *b, BN_CTX *ctx)
-	{
-	BIGNUM *aX, *aY, *bX, *bY;
-	BN_CTX *new_ctx = NULL;
-	int ret = -1;
-
-	if (EC_POINT_is_at_infinity(group, a))
-		{
-		return EC_POINT_is_at_infinity(group, b) ? 0 : 1;
-		}
-	
-	if (a->Z_is_one && b->Z_is_one)
-		{
-		return ((BN_cmp(&a->X, &b->X) == 0) && BN_cmp(&a->Y, &b->Y) == 0) ? 0 : 1;
-		}
-
-	if (ctx == NULL)
-		{
-		ctx = new_ctx = BN_CTX_new();
-		if (ctx == NULL)
-			return -1;
-		}
-
-	BN_CTX_start(ctx);
-	aX = BN_CTX_get(ctx);
-	aY = BN_CTX_get(ctx);
-	bX = BN_CTX_get(ctx);
-	bY = BN_CTX_get(ctx);
-	if (bY == NULL) goto err;
-
-	if (!EC_POINT_get_affine_coordinates_GF2m(group, a, aX, aY, ctx)) goto err;
-	if (!EC_POINT_get_affine_coordinates_GF2m(group, b, bX, bY, ctx)) goto err;
-	ret = ((BN_cmp(aX, bX) == 0) && BN_cmp(aY, bY) == 0) ? 0 : 1;
-
-  err:	
-	if (ctx) BN_CTX_end(ctx);
-	if (new_ctx) BN_CTX_free(new_ctx);
-	return ret;
-	}
-
-
-/* Forces the given EC_POINT to internally use affine coordinates. */
-int ec_GF2m_simple_make_affine(const EC_GROUP *group, EC_POINT *point, BN_CTX *ctx)
-	{
-	BN_CTX *new_ctx = NULL;
-	BIGNUM *x, *y;
-	int ret = 0;
-
-	if (point->Z_is_one || EC_POINT_is_at_infinity(group, point))
-		return 1;
-	
-	if (ctx == NULL)
-		{
-		ctx = new_ctx = BN_CTX_new();
-		if (ctx == NULL)
-			return 0;
-		}
-
-	BN_CTX_start(ctx);
-	x = BN_CTX_get(ctx);
-	y = BN_CTX_get(ctx);
-	if (y == NULL) goto err;
-	
-	if (!EC_POINT_get_affine_coordinates_GF2m(group, point, x, y, ctx)) goto err;
-	if (!BN_copy(&point->X, x)) goto err;
-	if (!BN_copy(&point->Y, y)) goto err;
-	if (!BN_one(&point->Z)) goto err;
-	
-	ret = 1;		
-
-  err:
-	if (ctx) BN_CTX_end(ctx);
-	if (new_ctx) BN_CTX_free(new_ctx);
-	return ret;
-	}
-
-
-/* Forces each of the EC_POINTs in the given array to use affine coordinates. */
-int ec_GF2m_simple_points_make_affine(const EC_GROUP *group, size_t num, EC_POINT *points[], BN_CTX *ctx)
-	{
-	size_t i;
-
-	for (i = 0; i < num; i++)
-		{
-		if (!group->meth->make_affine(group, points[i], ctx)) return 0;
-		}
-
-	return 1;
-	}
-
-
-/* Wrapper to simple binary polynomial field multiplication implementation. */
-int ec_GF2m_simple_field_mul(const EC_GROUP *group, BIGNUM *r, const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx)
-	{
-	return BN_GF2m_mod_mul_arr(r, a, b, group->poly, ctx);
-	}
-
-
-/* Wrapper to simple binary polynomial field squaring implementation. */
-int ec_GF2m_simple_field_sqr(const EC_GROUP *group, BIGNUM *r, const BIGNUM *a, BN_CTX *ctx)
-	{
-	return BN_GF2m_mod_sqr_arr(r, a, group->poly, ctx);
-	}
-
-
-/* Wrapper to simple binary polynomial field division implementation. */
-int ec_GF2m_simple_field_div(const EC_GROUP *group, BIGNUM *r, const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx)
-	{
-	return BN_GF2m_mod_div(r, a, b, &group->field, ctx);
-	}
+/* crypto/ec/ec2_smpl.c */

+/* ====================================================================

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

+ *

+ * The Elliptic Curve Public-Key Crypto Library (ECC Code) included

+ * herein is developed by SUN MICROSYSTEMS, INC., and is contributed

+ * to the OpenSSL project.

+ *

+ * The ECC Code is licensed pursuant to the OpenSSL open source

+ * license provided below.

+ *

+ * The software is originally written by Sheueling Chang Shantz and

+ * Douglas Stebila of Sun Microsystems Laboratories.

+ *

+ */

+/* ====================================================================

+ * 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).

+ *

+ */

+

+#include <openssl/err.h>

+

+#include "ec_lcl.h"

+

+

+const EC_METHOD *EC_GF2m_simple_method(void)

+	{

+	static const EC_METHOD ret = {

+		NID_X9_62_characteristic_two_field,

+		ec_GF2m_simple_group_init,

+		ec_GF2m_simple_group_finish,

+		ec_GF2m_simple_group_clear_finish,

+		ec_GF2m_simple_group_copy,

+		ec_GF2m_simple_group_set_curve,

+		ec_GF2m_simple_group_get_curve,

+		ec_GF2m_simple_group_get_degree,

+		ec_GF2m_simple_group_check_discriminant,

+		ec_GF2m_simple_point_init,

+		ec_GF2m_simple_point_finish,

+		ec_GF2m_simple_point_clear_finish,

+		ec_GF2m_simple_point_copy,

+		ec_GF2m_simple_point_set_to_infinity,

+		0 /* set_Jprojective_coordinates_GFp */,

+		0 /* get_Jprojective_coordinates_GFp */,

+		ec_GF2m_simple_point_set_affine_coordinates,

+		ec_GF2m_simple_point_get_affine_coordinates,

+		ec_GF2m_simple_set_compressed_coordinates,

+		ec_GF2m_simple_point2oct,

+		ec_GF2m_simple_oct2point,

+		ec_GF2m_simple_add,

+		ec_GF2m_simple_dbl,

+		ec_GF2m_simple_invert,

+		ec_GF2m_simple_is_at_infinity,

+		ec_GF2m_simple_is_on_curve,

+		ec_GF2m_simple_cmp,

+		ec_GF2m_simple_make_affine,

+		ec_GF2m_simple_points_make_affine,

+

+		/* the following three method functions are defined in ec2_mult.c */

+		ec_GF2m_simple_mul,

+		ec_GF2m_precompute_mult,

+		ec_GF2m_have_precompute_mult,

+

+		ec_GF2m_simple_field_mul,

+		ec_GF2m_simple_field_sqr,

+		ec_GF2m_simple_field_div,

+		0 /* field_encode */,

+		0 /* field_decode */,

+		0 /* field_set_to_one */ };

+

+	return &ret;

+	}

+

+

+/* Initialize a GF(2^m)-based EC_GROUP structure.

+ * Note that all other members are handled by EC_GROUP_new.

+ */

+int ec_GF2m_simple_group_init(EC_GROUP *group)

+	{

+	BN_init(&group->field);

+	BN_init(&group->a);

+	BN_init(&group->b);

+	return 1;

+	}

+

+

+/* Free a GF(2^m)-based EC_GROUP structure.

+ * Note that all other members are handled by EC_GROUP_free.

+ */

+void ec_GF2m_simple_group_finish(EC_GROUP *group)

+	{

+	BN_free(&group->field);

+	BN_free(&group->a);

+	BN_free(&group->b);

+	}

+

+

+/* Clear and free a GF(2^m)-based EC_GROUP structure.

+ * Note that all other members are handled by EC_GROUP_clear_free.

+ */

+void ec_GF2m_simple_group_clear_finish(EC_GROUP *group)

+	{

+	BN_clear_free(&group->field);

+	BN_clear_free(&group->a);

+	BN_clear_free(&group->b);

+	group->poly[0] = 0;

+	group->poly[1] = 0;

+	group->poly[2] = 0;

+	group->poly[3] = 0;

+	group->poly[4] = 0;

+	group->poly[5] = -1;

+	}

+

+

+/* Copy a GF(2^m)-based EC_GROUP structure.

+ * Note that all other members are handled by EC_GROUP_copy.

+ */

+int ec_GF2m_simple_group_copy(EC_GROUP *dest, const EC_GROUP *src)

+	{

+	int i;

+	if (!BN_copy(&dest->field, &src->field)) return 0;

+	if (!BN_copy(&dest->a, &src->a)) return 0;

+	if (!BN_copy(&dest->b, &src->b)) return 0;

+	dest->poly[0] = src->poly[0];

+	dest->poly[1] = src->poly[1];

+	dest->poly[2] = src->poly[2];

+	dest->poly[3] = src->poly[3];

+	dest->poly[4] = src->poly[4];

+	dest->poly[5] = src->poly[5];

+	if (bn_wexpand(&dest->a, (int)(dest->poly[0] + BN_BITS2 - 1) / BN_BITS2) == NULL) return 0;

+	if (bn_wexpand(&dest->b, (int)(dest->poly[0] + BN_BITS2 - 1) / BN_BITS2) == NULL) return 0;

+	for (i = dest->a.top; i < dest->a.dmax; i++) dest->a.d[i] = 0;

+	for (i = dest->b.top; i < dest->b.dmax; i++) dest->b.d[i] = 0;

+	return 1;

+	}

+

+

+/* Set the curve parameters of an EC_GROUP structure. */

+int ec_GF2m_simple_group_set_curve(EC_GROUP *group,

+	const BIGNUM *p, const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx)

+	{

+	int ret = 0, i;

+

+	/* group->field */

+	if (!BN_copy(&group->field, p)) goto err;

+	i = BN_GF2m_poly2arr(&group->field, group->poly, 6) - 1;

+	if ((i != 5) && (i != 3))

+		{

+		ECerr(EC_F_EC_GF2M_SIMPLE_GROUP_SET_CURVE, EC_R_UNSUPPORTED_FIELD);

+		goto err;

+		}

+

+	/* group->a */

+	if (!BN_GF2m_mod_arr(&group->a, a, group->poly)) goto err;

+	if(bn_wexpand(&group->a, (int)(group->poly[0] + BN_BITS2 - 1) / BN_BITS2) == NULL) goto err;

+	for (i = group->a.top; i < group->a.dmax; i++) group->a.d[i] = 0;

+	

+	/* group->b */

+	if (!BN_GF2m_mod_arr(&group->b, b, group->poly)) goto err;

+	if(bn_wexpand(&group->b, (int)(group->poly[0] + BN_BITS2 - 1) / BN_BITS2) == NULL) goto err;

+	for (i = group->b.top; i < group->b.dmax; i++) group->b.d[i] = 0;

+		

+	ret = 1;

+  err:

+	return ret;

+	}

+

+

+/* Get the curve parameters of an EC_GROUP structure.

+ * If p, a, or b are NULL then there values will not be set but the method will return with success.

+ */

+int ec_GF2m_simple_group_get_curve(const EC_GROUP *group, BIGNUM *p, BIGNUM *a, BIGNUM *b, BN_CTX *ctx)

+	{

+	int ret = 0;

+	

+	if (p != NULL)

+		{

+		if (!BN_copy(p, &group->field)) return 0;

+		}

+

+	if (a != NULL)

+		{

+		if (!BN_copy(a, &group->a)) goto err;

+		}

+

+	if (b != NULL)

+		{

+		if (!BN_copy(b, &group->b)) goto err;

+		}

+	

+	ret = 1;

+	

+  err:

+	return ret;

+	}

+

+

+/* Gets the degree of the field.  For a curve over GF(2^m) this is the value m. */

+int ec_GF2m_simple_group_get_degree(const EC_GROUP *group)

+	{

+	return BN_num_bits(&group->field)-1;

+	}

+

+

+/* Checks the discriminant of the curve.

+ * y^2 + x*y = x^3 + a*x^2 + b is an elliptic curve <=> b != 0 (mod p) 

+ */

+int ec_GF2m_simple_group_check_discriminant(const EC_GROUP *group, BN_CTX *ctx)

+	{

+	int ret = 0;

+	BIGNUM *b;

+	BN_CTX *new_ctx = NULL;

+

+	if (ctx == NULL)

+		{

+		ctx = new_ctx = BN_CTX_new();

+		if (ctx == NULL)

+			{

+			ECerr(EC_F_EC_GF2M_SIMPLE_GROUP_CHECK_DISCRIMINANT, ERR_R_MALLOC_FAILURE);

+			goto err;

+			}

+		}

+	BN_CTX_start(ctx);

+	b = BN_CTX_get(ctx);

+	if (b == NULL) goto err;

+

+	if (!BN_GF2m_mod_arr(b, &group->b, group->poly)) goto err;

+	

+	/* check the discriminant:

+	 * y^2 + x*y = x^3 + a*x^2 + b is an elliptic curve <=> b != 0 (mod p) 

+	 */

+	if (BN_is_zero(b)) goto err;

+

+	ret = 1;

+

+err:

+	if (ctx != NULL)

+		BN_CTX_end(ctx);

+	if (new_ctx != NULL)

+		BN_CTX_free(new_ctx);

+	return ret;

+	}

+

+

+/* Initializes an EC_POINT. */

+int ec_GF2m_simple_point_init(EC_POINT *point)

+	{

+	BN_init(&point->X);

+	BN_init(&point->Y);

+	BN_init(&point->Z);

+	return 1;

+	}

+

+

+/* Frees an EC_POINT. */

+void ec_GF2m_simple_point_finish(EC_POINT *point)

+	{

+	BN_free(&point->X);

+	BN_free(&point->Y);

+	BN_free(&point->Z);

+	}

+

+

+/* Clears and frees an EC_POINT. */

+void ec_GF2m_simple_point_clear_finish(EC_POINT *point)

+	{

+	BN_clear_free(&point->X);

+	BN_clear_free(&point->Y);

+	BN_clear_free(&point->Z);

+	point->Z_is_one = 0;

+	}

+

+

+/* Copy the contents of one EC_POINT into another.  Assumes dest is initialized. */

+int ec_GF2m_simple_point_copy(EC_POINT *dest, const EC_POINT *src)

+	{

+	if (!BN_copy(&dest->X, &src->X)) return 0;

+	if (!BN_copy(&dest->Y, &src->Y)) return 0;

+	if (!BN_copy(&dest->Z, &src->Z)) return 0;

+	dest->Z_is_one = src->Z_is_one;

+

+	return 1;

+	}

+

+

+/* Set an EC_POINT to the point at infinity.  

+ * A point at infinity is represented by having Z=0.

+ */

+int ec_GF2m_simple_point_set_to_infinity(const EC_GROUP *group, EC_POINT *point)

+	{

+	point->Z_is_one = 0;

+	BN_zero(&point->Z);

+	return 1;

+	}

+

+

+/* Set the coordinates of an EC_POINT using affine coordinates. 

+ * Note that the simple implementation only uses affine coordinates.

+ */

+int ec_GF2m_simple_point_set_affine_coordinates(const EC_GROUP *group, EC_POINT *point,

+	const BIGNUM *x, const BIGNUM *y, BN_CTX *ctx)

+	{

+	int ret = 0;	

+	if (x == NULL || y == NULL)

+		{

+		ECerr(EC_F_EC_GF2M_SIMPLE_POINT_SET_AFFINE_COORDINATES, ERR_R_PASSED_NULL_PARAMETER);

+		return 0;

+		}

+

+	if (!BN_copy(&point->X, x)) goto err;

+	BN_set_negative(&point->X, 0);

+	if (!BN_copy(&point->Y, y)) goto err;

+	BN_set_negative(&point->Y, 0);

+	if (!BN_copy(&point->Z, BN_value_one())) goto err;

+	BN_set_negative(&point->Z, 0);

+	point->Z_is_one = 1;

+	ret = 1;

+

+  err:

+	return ret;

+	}

+

+

+/* Gets the affine coordinates of an EC_POINT. 

+ * Note that the simple implementation only uses affine coordinates.

+ */

+int ec_GF2m_simple_point_get_affine_coordinates(const EC_GROUP *group, const EC_POINT *point,

+	BIGNUM *x, BIGNUM *y, BN_CTX *ctx)

+	{

+	int ret = 0;

+

+	if (EC_POINT_is_at_infinity(group, point))

+		{

+		ECerr(EC_F_EC_GF2M_SIMPLE_POINT_GET_AFFINE_COORDINATES, EC_R_POINT_AT_INFINITY);

+		return 0;

+		}

+

+	if (BN_cmp(&point->Z, BN_value_one())) 

+		{

+		ECerr(EC_F_EC_GF2M_SIMPLE_POINT_GET_AFFINE_COORDINATES, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);

+		return 0;

+		}

+	if (x != NULL)

+		{

+		if (!BN_copy(x, &point->X)) goto err;

+		BN_set_negative(x, 0);

+		}

+	if (y != NULL)

+		{

+		if (!BN_copy(y, &point->Y)) goto err;

+		BN_set_negative(y, 0);

+		}

+	ret = 1;

+		

+ err:

+	return ret;

+	}

+

+

+/* Calculates and sets the affine coordinates of an EC_POINT from the given

+ * compressed coordinates.  Uses algorithm 2.3.4 of SEC 1. 

+ * Note that the simple implementation only uses affine coordinates.

+ *

+ * The method is from the following publication:

+ * 

+ *     Harper, Menezes, Vanstone:

+ *     "Public-Key Cryptosystems with Very Small Key Lengths",

+ *     EUROCRYPT '92, Springer-Verlag LNCS 658,

+ *     published February 1993

+ *

+ * US Patents 6,141,420 and 6,618,483 (Vanstone, Mullin, Agnew) describe

+ * the same method, but claim no priority date earlier than July 29, 1994

+ * (and additionally fail to cite the EUROCRYPT '92 publication as prior art).

+ */

+int ec_GF2m_simple_set_compressed_coordinates(const EC_GROUP *group, EC_POINT *point,

+	const BIGNUM *x_, int y_bit, BN_CTX *ctx)

+	{

+	BN_CTX *new_ctx = NULL;

+	BIGNUM *tmp, *x, *y, *z;

+	int ret = 0, z0;

+

+	/* clear error queue */

+	ERR_clear_error();

+

+	if (ctx == NULL)

+		{

+		ctx = new_ctx = BN_CTX_new();

+		if (ctx == NULL)

+			return 0;

+		}

+

+	y_bit = (y_bit != 0) ? 1 : 0;

+

+	BN_CTX_start(ctx);

+	tmp = BN_CTX_get(ctx);

+	x = BN_CTX_get(ctx);

+	y = BN_CTX_get(ctx);

+	z = BN_CTX_get(ctx);

+	if (z == NULL) goto err;

+

+	if (!BN_GF2m_mod_arr(x, x_, group->poly)) goto err;

+	if (BN_is_zero(x))

+		{

+		if (!BN_GF2m_mod_sqrt_arr(y, &group->b, group->poly, ctx)) goto err;

+		}

+	else

+		{

+		if (!group->meth->field_sqr(group, tmp, x, ctx)) goto err;

+		if (!group->meth->field_div(group, tmp, &group->b, tmp, ctx)) goto err;

+		if (!BN_GF2m_add(tmp, &group->a, tmp)) goto err;

+		if (!BN_GF2m_add(tmp, x, tmp)) goto err;

+		if (!BN_GF2m_mod_solve_quad_arr(z, tmp, group->poly, ctx))

+			{

+			unsigned long err = ERR_peek_last_error();

+			

+			if (ERR_GET_LIB(err) == ERR_LIB_BN && ERR_GET_REASON(err) == BN_R_NO_SOLUTION)

+				{

+				ERR_clear_error();

+				ECerr(EC_F_EC_GF2M_SIMPLE_SET_COMPRESSED_COORDINATES, EC_R_INVALID_COMPRESSED_POINT);

+				}

+			else

+				ECerr(EC_F_EC_GF2M_SIMPLE_SET_COMPRESSED_COORDINATES, ERR_R_BN_LIB);

+			goto err;

+			}

+		z0 = (BN_is_odd(z)) ? 1 : 0;

+		if (!group->meth->field_mul(group, y, x, z, ctx)) goto err;

+		if (z0 != y_bit)

+			{

+			if (!BN_GF2m_add(y, y, x)) goto err;

+			}

+		}

+

+	if (!EC_POINT_set_affine_coordinates_GF2m(group, point, x, y, ctx)) goto err;

+

+	ret = 1;

+

+ err:

+	BN_CTX_end(ctx);

+	if (new_ctx != NULL)

+		BN_CTX_free(new_ctx);

+	return ret;

+	}

+

+

+/* Converts an EC_POINT to an octet string.  

+ * If buf is NULL, the encoded length will be returned.

+ * If the length len of buf is smaller than required an error will be returned.

+ */

+size_t ec_GF2m_simple_point2oct(const EC_GROUP *group, const EC_POINT *point, point_conversion_form_t form,

+	unsigned char *buf, size_t len, BN_CTX *ctx)

+	{

+	size_t ret;

+	BN_CTX *new_ctx = NULL;

+	int used_ctx = 0;

+	BIGNUM *x, *y, *yxi;

+	size_t field_len, i, skip;

+

+	if ((form != POINT_CONVERSION_COMPRESSED)

+		&& (form != POINT_CONVERSION_UNCOMPRESSED)

+		&& (form != POINT_CONVERSION_HYBRID))

+		{

+		ECerr(EC_F_EC_GF2M_SIMPLE_POINT2OCT, EC_R_INVALID_FORM);

+		goto err;

+		}

+

+	if (EC_POINT_is_at_infinity(group, point))

+		{

+		/* encodes to a single 0 octet */

+		if (buf != NULL)

+			{

+			if (len < 1)

+				{

+				ECerr(EC_F_EC_GF2M_SIMPLE_POINT2OCT, EC_R_BUFFER_TOO_SMALL);

+				return 0;

+				}

+			buf[0] = 0;

+			}

+		return 1;

+		}

+

+

+	/* ret := required output buffer length */

+	field_len = (EC_GROUP_get_degree(group) + 7) / 8;

+	ret = (form == POINT_CONVERSION_COMPRESSED) ? 1 + field_len : 1 + 2*field_len;

+

+	/* if 'buf' is NULL, just return required length */

+	if (buf != NULL)

+		{

+		if (len < ret)

+			{

+			ECerr(EC_F_EC_GF2M_SIMPLE_POINT2OCT, EC_R_BUFFER_TOO_SMALL);

+			goto err;

+			}

+

+		if (ctx == NULL)

+			{

+			ctx = new_ctx = BN_CTX_new();

+			if (ctx == NULL)

+				return 0;

+			}

+

+		BN_CTX_start(ctx);

+		used_ctx = 1;

+		x = BN_CTX_get(ctx);

+		y = BN_CTX_get(ctx);

+		yxi = BN_CTX_get(ctx);

+		if (yxi == NULL) goto err;

+

+		if (!EC_POINT_get_affine_coordinates_GF2m(group, point, x, y, ctx)) goto err;

+

+		buf[0] = form;

+		if ((form != POINT_CONVERSION_UNCOMPRESSED) && !BN_is_zero(x))

+			{

+			if (!group->meth->field_div(group, yxi, y, x, ctx)) goto err;

+			if (BN_is_odd(yxi)) buf[0]++;

+			}

+

+		i = 1;

+		

+		skip = field_len - BN_num_bytes(x);

+		if (skip > field_len)

+			{

+			ECerr(EC_F_EC_GF2M_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERROR);

+			goto err;

+			}

+		while (skip > 0)

+			{

+			buf[i++] = 0;

+			skip--;

+			}

+		skip = BN_bn2bin(x, buf + i);

+		i += skip;

+		if (i != 1 + field_len)

+			{

+			ECerr(EC_F_EC_GF2M_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERROR);

+			goto err;

+			}

+

+		if (form == POINT_CONVERSION_UNCOMPRESSED || form == POINT_CONVERSION_HYBRID)

+			{

+			skip = field_len - BN_num_bytes(y);

+			if (skip > field_len)

+				{

+				ECerr(EC_F_EC_GF2M_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERROR);

+				goto err;

+				}

+			while (skip > 0)

+				{

+				buf[i++] = 0;

+				skip--;

+				}

+			skip = BN_bn2bin(y, buf + i);

+			i += skip;

+			}

+

+		if (i != ret)

+			{

+			ECerr(EC_F_EC_GF2M_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERROR);

+			goto err;

+			}

+		}

+	

+	if (used_ctx)

+		BN_CTX_end(ctx);

+	if (new_ctx != NULL)

+		BN_CTX_free(new_ctx);

+	return ret;

+

+ err:

+	if (used_ctx)

+		BN_CTX_end(ctx);

+	if (new_ctx != NULL)

+		BN_CTX_free(new_ctx);

+	return 0;

+	}

+

+

+/* Converts an octet string representation to an EC_POINT. 

+ * Note that the simple implementation only uses affine coordinates.

+ */

+int ec_GF2m_simple_oct2point(const EC_GROUP *group, EC_POINT *point,

+	const unsigned char *buf, size_t len, BN_CTX *ctx)

+	{

+	point_conversion_form_t form;

+	int y_bit;

+	BN_CTX *new_ctx = NULL;

+	BIGNUM *x, *y, *yxi;

+	size_t field_len, enc_len;

+	int ret = 0;

+

+	if (len == 0)

+		{

+		ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_BUFFER_TOO_SMALL);

+		return 0;

+		}

+	form = buf[0];

+	y_bit = form & 1;

+	form = form & ~1U;

+	if ((form != 0)	&& (form != POINT_CONVERSION_COMPRESSED)

+		&& (form != POINT_CONVERSION_UNCOMPRESSED)

+		&& (form != POINT_CONVERSION_HYBRID))

+		{

+		ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);

+		return 0;

+		}

+	if ((form == 0 || form == POINT_CONVERSION_UNCOMPRESSED) && y_bit)

+		{

+		ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);

+		return 0;

+		}

+

+	if (form == 0)

+		{

+		if (len != 1)

+			{

+			ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);

+			return 0;

+			}

+

+		return EC_POINT_set_to_infinity(group, point);

+		}

+	

+	field_len = (EC_GROUP_get_degree(group) + 7) / 8;

+	enc_len = (form == POINT_CONVERSION_COMPRESSED) ? 1 + field_len : 1 + 2*field_len;

+

+	if (len != enc_len)

+		{

+		ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);

+		return 0;

+		}

+

+	if (ctx == NULL)

+		{

+		ctx = new_ctx = BN_CTX_new();

+		if (ctx == NULL)

+			return 0;

+		}

+

+	BN_CTX_start(ctx);

+	x = BN_CTX_get(ctx);

+	y = BN_CTX_get(ctx);

+	yxi = BN_CTX_get(ctx);

+	if (yxi == NULL) goto err;

+

+	if (!BN_bin2bn(buf + 1, field_len, x)) goto err;

+	if (BN_ucmp(x, &group->field) >= 0)

+		{

+		ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);

+		goto err;

+		}

+

+	if (form == POINT_CONVERSION_COMPRESSED)

+		{

+		if (!EC_POINT_set_compressed_coordinates_GF2m(group, point, x, y_bit, ctx)) goto err;

+		}

+	else

+		{

+		if (!BN_bin2bn(buf + 1 + field_len, field_len, y)) goto err;

+		if (BN_ucmp(y, &group->field) >= 0)

+			{

+			ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);

+			goto err;

+			}

+		if (form == POINT_CONVERSION_HYBRID)

+			{

+			if (!group->meth->field_div(group, yxi, y, x, ctx)) goto err;

+			if (y_bit != BN_is_odd(yxi))

+				{

+				ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);

+				goto err;

+				}

+			}

+

+		if (!EC_POINT_set_affine_coordinates_GF2m(group, point, x, y, ctx)) goto err;

+		}

+	

+	if (!EC_POINT_is_on_curve(group, point, ctx)) /* test required by X9.62 */

+		{

+		ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_POINT_IS_NOT_ON_CURVE);

+		goto err;

+		}

+

+	ret = 1;

+	

+ err:

+	BN_CTX_end(ctx);

+	if (new_ctx != NULL)

+		BN_CTX_free(new_ctx);

+	return ret;

+	}

+

+

+/* Computes a + b and stores the result in r.  r could be a or b, a could be b.

+ * Uses algorithm A.10.2 of IEEE P1363.

+ */

+int ec_GF2m_simple_add(const EC_GROUP *group, EC_POINT *r, const EC_POINT *a, const EC_POINT *b, BN_CTX *ctx)

+	{

+	BN_CTX *new_ctx = NULL;

+	BIGNUM *x0, *y0, *x1, *y1, *x2, *y2, *s, *t;

+	int ret = 0;

+	

+	if (EC_POINT_is_at_infinity(group, a))

+		{

+		if (!EC_POINT_copy(r, b)) return 0;

+		return 1;

+		}

+

+	if (EC_POINT_is_at_infinity(group, b))

+		{

+		if (!EC_POINT_copy(r, a)) return 0;

+		return 1;

+		}

+

+	if (ctx == NULL)

+		{

+		ctx = new_ctx = BN_CTX_new();

+		if (ctx == NULL)

+			return 0;

+		}

+

+	BN_CTX_start(ctx);

+	x0 = BN_CTX_get(ctx);

+	y0 = BN_CTX_get(ctx);

+	x1 = BN_CTX_get(ctx);

+	y1 = BN_CTX_get(ctx);

+	x2 = BN_CTX_get(ctx);

+	y2 = BN_CTX_get(ctx);

+	s = BN_CTX_get(ctx);

+	t = BN_CTX_get(ctx);

+	if (t == NULL) goto err;

+

+	if (a->Z_is_one) 

+		{

+		if (!BN_copy(x0, &a->X)) goto err;

+		if (!BN_copy(y0, &a->Y)) goto err;

+		}

+	else

+		{

+		if (!EC_POINT_get_affine_coordinates_GF2m(group, a, x0, y0, ctx)) goto err;

+		}

+	if (b->Z_is_one) 

+		{

+		if (!BN_copy(x1, &b->X)) goto err;

+		if (!BN_copy(y1, &b->Y)) goto err;

+		}

+	else

+		{

+		if (!EC_POINT_get_affine_coordinates_GF2m(group, b, x1, y1, ctx)) goto err;

+		}

+

+

+	if (BN_GF2m_cmp(x0, x1))

+		{

+		if (!BN_GF2m_add(t, x0, x1)) goto err;

+		if (!BN_GF2m_add(s, y0, y1)) goto err;

+		if (!group->meth->field_div(group, s, s, t, ctx)) goto err;

+		if (!group->meth->field_sqr(group, x2, s, ctx)) goto err;

+		if (!BN_GF2m_add(x2, x2, &group->a)) goto err;

+		if (!BN_GF2m_add(x2, x2, s)) goto err;

+		if (!BN_GF2m_add(x2, x2, t)) goto err;

+		}

+	else

+		{

+		if (BN_GF2m_cmp(y0, y1) || BN_is_zero(x1))

+			{

+			if (!EC_POINT_set_to_infinity(group, r)) goto err;

+			ret = 1;

+			goto err;

+			}

+		if (!group->meth->field_div(group, s, y1, x1, ctx)) goto err;

+		if (!BN_GF2m_add(s, s, x1)) goto err;

+		

+		if (!group->meth->field_sqr(group, x2, s, ctx)) goto err;

+		if (!BN_GF2m_add(x2, x2, s)) goto err;

+		if (!BN_GF2m_add(x2, x2, &group->a)) goto err;

+		}

+

+	if (!BN_GF2m_add(y2, x1, x2)) goto err;

+	if (!group->meth->field_mul(group, y2, y2, s, ctx)) goto err;

+	if (!BN_GF2m_add(y2, y2, x2)) goto err;

+	if (!BN_GF2m_add(y2, y2, y1)) goto err;

+

+	if (!EC_POINT_set_affine_coordinates_GF2m(group, r, x2, y2, ctx)) goto err;

+

+	ret = 1;

+

+ err:

+	BN_CTX_end(ctx);

+	if (new_ctx != NULL)

+		BN_CTX_free(new_ctx);

+	return ret;

+	}

+

+

+/* Computes 2 * a and stores the result in r.  r could be a.

+ * Uses algorithm A.10.2 of IEEE P1363.

+ */

+int ec_GF2m_simple_dbl(const EC_GROUP *group, EC_POINT *r, const EC_POINT *a, BN_CTX *ctx)

+	{

+	return ec_GF2m_simple_add(group, r, a, a, ctx);

+	}

+

+

+int ec_GF2m_simple_invert(const EC_GROUP *group, EC_POINT *point, BN_CTX *ctx)

+	{

+	if (EC_POINT_is_at_infinity(group, point) || BN_is_zero(&point->Y))

+		/* point is its own inverse */

+		return 1;

+	

+	if (!EC_POINT_make_affine(group, point, ctx)) return 0;

+	return BN_GF2m_add(&point->Y, &point->X, &point->Y);

+	}

+

+

+/* Indicates whether the given point is the point at infinity. */

+int ec_GF2m_simple_is_at_infinity(const EC_GROUP *group, const EC_POINT *point)

+	{

+	return BN_is_zero(&point->Z);

+	}

+

+

+/* Determines whether the given EC_POINT is an actual point on the curve defined

+ * in the EC_GROUP.  A point is valid if it satisfies the Weierstrass equation:

+ *      y^2 + x*y = x^3 + a*x^2 + b.

+ */

+int ec_GF2m_simple_is_on_curve(const EC_GROUP *group, const EC_POINT *point, BN_CTX *ctx)

+	{

+	int ret = -1;

+	BN_CTX *new_ctx = NULL;

+	BIGNUM *lh, *y2;

+	int (*field_mul)(const EC_GROUP *, BIGNUM *, const BIGNUM *, const BIGNUM *, BN_CTX *);

+	int (*field_sqr)(const EC_GROUP *, BIGNUM *, const BIGNUM *, BN_CTX *);

+

+	if (EC_POINT_is_at_infinity(group, point))

+		return 1;

+

+	field_mul = group->meth->field_mul;

+	field_sqr = group->meth->field_sqr;	

+

+	/* only support affine coordinates */

+	if (!point->Z_is_one) goto err;

+

+	if (ctx == NULL)

+		{

+		ctx = new_ctx = BN_CTX_new();

+		if (ctx == NULL)

+			return -1;

+		}

+

+	BN_CTX_start(ctx);

+	y2 = BN_CTX_get(ctx);

+	lh = BN_CTX_get(ctx);

+	if (lh == NULL) goto err;

+

+	/* We have a curve defined by a Weierstrass equation

+	 *      y^2 + x*y = x^3 + a*x^2 + b.

+	 *  <=> x^3 + a*x^2 + x*y + b + y^2 = 0

+	 *  <=> ((x + a) * x + y ) * x + b + y^2 = 0

+	 */

+	if (!BN_GF2m_add(lh, &point->X, &group->a)) goto err;

+	if (!field_mul(group, lh, lh, &point->X, ctx)) goto err;

+	if (!BN_GF2m_add(lh, lh, &point->Y)) goto err;

+	if (!field_mul(group, lh, lh, &point->X, ctx)) goto err;

+	if (!BN_GF2m_add(lh, lh, &group->b)) goto err;

+	if (!field_sqr(group, y2, &point->Y, ctx)) goto err;

+	if (!BN_GF2m_add(lh, lh, y2)) goto err;

+	ret = BN_is_zero(lh);

+ err:

+	if (ctx) BN_CTX_end(ctx);

+	if (new_ctx) BN_CTX_free(new_ctx);

+	return ret;

+	}

+

+

+/* Indicates whether two points are equal.

+ * Return values:

+ *  -1   error

+ *   0   equal (in affine coordinates)

+ *   1   not equal

+ */

+int ec_GF2m_simple_cmp(const EC_GROUP *group, const EC_POINT *a, const EC_POINT *b, BN_CTX *ctx)

+	{

+	BIGNUM *aX, *aY, *bX, *bY;

+	BN_CTX *new_ctx = NULL;

+	int ret = -1;

+

+	if (EC_POINT_is_at_infinity(group, a))

+		{

+		return EC_POINT_is_at_infinity(group, b) ? 0 : 1;

+		}

+

+	if (EC_POINT_is_at_infinity(group, b))

+		return 1;

+	

+	if (a->Z_is_one && b->Z_is_one)

+		{

+		return ((BN_cmp(&a->X, &b->X) == 0) && BN_cmp(&a->Y, &b->Y) == 0) ? 0 : 1;

+		}

+

+	if (ctx == NULL)

+		{

+		ctx = new_ctx = BN_CTX_new();

+		if (ctx == NULL)

+			return -1;

+		}

+

+	BN_CTX_start(ctx);

+	aX = BN_CTX_get(ctx);

+	aY = BN_CTX_get(ctx);

+	bX = BN_CTX_get(ctx);

+	bY = BN_CTX_get(ctx);

+	if (bY == NULL) goto err;

+

+	if (!EC_POINT_get_affine_coordinates_GF2m(group, a, aX, aY, ctx)) goto err;

+	if (!EC_POINT_get_affine_coordinates_GF2m(group, b, bX, bY, ctx)) goto err;

+	ret = ((BN_cmp(aX, bX) == 0) && BN_cmp(aY, bY) == 0) ? 0 : 1;

+

+  err:	

+	if (ctx) BN_CTX_end(ctx);

+	if (new_ctx) BN_CTX_free(new_ctx);

+	return ret;

+	}

+

+

+/* Forces the given EC_POINT to internally use affine coordinates. */

+int ec_GF2m_simple_make_affine(const EC_GROUP *group, EC_POINT *point, BN_CTX *ctx)

+	{

+	BN_CTX *new_ctx = NULL;

+	BIGNUM *x, *y;

+	int ret = 0;

+

+	if (point->Z_is_one || EC_POINT_is_at_infinity(group, point))

+		return 1;

+	

+	if (ctx == NULL)

+		{

+		ctx = new_ctx = BN_CTX_new();

+		if (ctx == NULL)

+			return 0;

+		}

+

+	BN_CTX_start(ctx);

+	x = BN_CTX_get(ctx);

+	y = BN_CTX_get(ctx);

+	if (y == NULL) goto err;

+	

+	if (!EC_POINT_get_affine_coordinates_GF2m(group, point, x, y, ctx)) goto err;

+	if (!BN_copy(&point->X, x)) goto err;

+	if (!BN_copy(&point->Y, y)) goto err;

+	if (!BN_one(&point->Z)) goto err;

+	

+	ret = 1;		

+

+  err:

+	if (ctx) BN_CTX_end(ctx);

+	if (new_ctx) BN_CTX_free(new_ctx);

+	return ret;

+	}

+

+

+/* Forces each of the EC_POINTs in the given array to use affine coordinates. */

+int ec_GF2m_simple_points_make_affine(const EC_GROUP *group, size_t num, EC_POINT *points[], BN_CTX *ctx)

+	{

+	size_t i;

+

+	for (i = 0; i < num; i++)

+		{

+		if (!group->meth->make_affine(group, points[i], ctx)) return 0;

+		}

+

+	return 1;

+	}

+

+

+/* Wrapper to simple binary polynomial field multiplication implementation. */

+int ec_GF2m_simple_field_mul(const EC_GROUP *group, BIGNUM *r, const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx)

+	{

+	return BN_GF2m_mod_mul_arr(r, a, b, group->poly, ctx);

+	}

+

+

+/* Wrapper to simple binary polynomial field squaring implementation. */

+int ec_GF2m_simple_field_sqr(const EC_GROUP *group, BIGNUM *r, const BIGNUM *a, BN_CTX *ctx)

+	{

+	return BN_GF2m_mod_sqr_arr(r, a, group->poly, ctx);

+	}

+

+

+/* Wrapper to simple binary polynomial field division implementation. */

+int ec_GF2m_simple_field_div(const EC_GROUP *group, BIGNUM *r, const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx)

+	{

+	return BN_GF2m_mod_div(r, a, b, &group->field, ctx);

+	}