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-rw-r--r--openssl/crypto/ec/ec2_smpl.c2081
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);
+ }
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-26 21:37:35 +0000