/* crypto/ec/ecp_mont.c */

/*

 * Originally written by Bodo Moeller for the OpenSSL project.

 */

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

 * Copyright (c) 1998-2001 The OpenSSL Project.  All rights reserved.

 *

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

 * modification, are permitted provided that the following conditions

 * are met:

 *

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

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

 *

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

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

 *    the documentation and/or other materials provided with the

 *    distribution.

 *

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

 *    software must display the following acknowledgment:

 *    "This product includes software developed by the OpenSSL Project

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

 *

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

 *    endorse or promote products derived from this software without

 *    prior written permission. For written permission, please contact

 *    openssl-core@openssl.org.

 *

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

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

 *    permission of the OpenSSL Project.

 *

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

 *    acknowledgment:

 *    "This product includes software developed by the OpenSSL Project

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

 *

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

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

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

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

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

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

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

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

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

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

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

 * OF THE POSSIBILITY OF SUCH DAMAGE.

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

 *

 * This product includes cryptographic software written by Eric Young

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

 * Hudson (tjh@cryptsoft.com).

 *

 */

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

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

 * Portions of this software developed by SUN MICROSYSTEMS, INC.,

 * and contributed to the OpenSSL project.

 */

#include <openssl/err.h>

#ifdef OPENSSL_FIPS

# include <openssl/fips.h>

#endif

#include "ec_lcl.h"

const EC_METHOD *EC_GFp_mont_method(void)

{

    static const EC_METHOD ret = {

        EC_FLAGS_DEFAULT_OCT,

        NID_X9_62_prime_field,

        ec_GFp_mont_group_init,

        ec_GFp_mont_group_finish,

        ec_GFp_mont_group_clear_finish,

        ec_GFp_mont_group_copy,

        ec_GFp_mont_group_set_curve,

        ec_GFp_simple_group_get_curve,

        ec_GFp_simple_group_get_degree,

        ec_GFp_simple_group_check_discriminant,

        ec_GFp_simple_point_init,

        ec_GFp_simple_point_finish,

        ec_GFp_simple_point_clear_finish,

        ec_GFp_simple_point_copy,

        ec_GFp_simple_point_set_to_infinity,

        ec_GFp_simple_set_Jprojective_coordinates_GFp,

        ec_GFp_simple_get_Jprojective_coordinates_GFp,

        ec_GFp_simple_point_set_affine_coordinates,

        ec_GFp_simple_point_get_affine_coordinates,

        0, 0, 0,

        ec_GFp_simple_add,

        ec_GFp_simple_dbl,

        ec_GFp_simple_invert,

        ec_GFp_simple_is_at_infinity,

        ec_GFp_simple_is_on_curve,

        ec_GFp_simple_cmp,

        ec_GFp_simple_make_affine,

        ec_GFp_simple_points_make_affine,

        0 /* mul */ ,

        0 /* precompute_mult */ ,

        0 /* have_precompute_mult */ ,

        ec_GFp_mont_field_mul,

        ec_GFp_mont_field_sqr,

        0 /* field_div */ ,

        ec_GFp_mont_field_encode,

        ec_GFp_mont_field_decode,

        ec_GFp_mont_field_set_to_one

    };

#ifdef OPENSSL_FIPS

    if (FIPS_mode())

        return fips_ec_gfp_mont_method();

#endif

    return &ret;

}

int ec_GFp_mont_group_init(EC_GROUP *group)

{

    int ok;

    ok = ec_GFp_simple_group_init(group);

    group->field_data1 = NULL;

    group->field_data2 = NULL;

    return ok;

}

void ec_GFp_mont_group_finish(EC_GROUP *group)

{

    if (group->field_data1 != NULL) {

        BN_MONT_CTX_free(group->field_data1);

        group->field_data1 = NULL;

    }

    if (group->field_data2 != NULL) {

        BN_free(group->field_data2);

        group->field_data2 = NULL;

    }

    ec_GFp_simple_group_finish(group);

}

void ec_GFp_mont_group_clear_finish(EC_GROUP *group)

{

    if (group->field_data1 != NULL) {

        BN_MONT_CTX_free(group->field_data1);

        group->field_data1 = NULL;

    }

    if (group->field_data2 != NULL) {

        BN_clear_free(group->field_data2);

        group->field_data2 = NULL;

    }

    ec_GFp_simple_group_clear_finish(group);

}

int ec_GFp_mont_group_copy(EC_GROUP *dest, const EC_GROUP *src)

{

    if (dest->field_data1 != NULL) {

        BN_MONT_CTX_free(dest->field_data1);

        dest->field_data1 = NULL;

    }

    if (dest->field_data2 != NULL) {

        BN_clear_free(dest->field_data2);

        dest->field_data2 = NULL;

    }

    if (!ec_GFp_simple_group_copy(dest, src))

        return 0;

    if (src->field_data1 != NULL) {

        dest->field_data1 = BN_MONT_CTX_new();

        if (dest->field_data1 == NULL)

            return 0;

        if (!BN_MONT_CTX_copy(dest->field_data1, src->field_data1))

            goto err;

    }

    if (src->field_data2 != NULL) {

        dest->field_data2 = BN_dup(src->field_data2);

        if (dest->field_data2 == NULL)

            goto err;

    }

    return 1;

 err:

    if (dest->field_data1 != NULL) {

        BN_MONT_CTX_free(dest->field_data1);

        dest->field_data1 = NULL;

    }

    return 0;

}

int ec_GFp_mont_group_set_curve(EC_GROUP *group, const BIGNUM *p,

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

{

    BN_CTX *new_ctx = NULL;

    BN_MONT_CTX *mont = NULL;

    BIGNUM *one = NULL;

    int ret = 0;

    if (group->field_data1 != NULL) {

        BN_MONT_CTX_free(group->field_data1);

        group->field_data1 = NULL;

    }

    if (group->field_data2 != NULL) {

        BN_free(group->field_data2);

        group->field_data2 = NULL;

    }

    if (ctx == NULL) {

        ctx = new_ctx = BN_CTX_new();

        if (ctx == NULL)

            return 0;

    }

    mont = BN_MONT_CTX_new();

    if (mont == NULL)

        goto err;

    if (!BN_MONT_CTX_set(mont, p, ctx)) {

        ECerr(EC_F_EC_GFP_MONT_GROUP_SET_CURVE, ERR_R_BN_LIB);

        goto err;

    }

    one = BN_new();

    if (one == NULL)

        goto err;

    if (!BN_to_montgomery(one, BN_value_one(), mont, ctx))

        goto err;

    group->field_data1 = mont;

    mont = NULL;

    group->field_data2 = one;

    one = NULL;

    ret = ec_GFp_simple_group_set_curve(group, p, a, b, ctx);

    if (!ret) {

        BN_MONT_CTX_free(group->field_data1);

        group->field_data1 = NULL;

        BN_free(group->field_data2);

        group->field_data2 = NULL;

    }

 err:

    if (new_ctx != NULL)

        BN_CTX_free(new_ctx);

    if (mont != NULL)

        BN_MONT_CTX_free(mont);

    if (one != NULL)

        BN_free(one);

    return ret;

}

int ec_GFp_mont_field_mul(const EC_GROUP *group, BIGNUM *r, const BIGNUM *a,

                          const BIGNUM *b, BN_CTX *ctx)

{

    if (group->field_data1 == NULL) {

        ECerr(EC_F_EC_GFP_MONT_FIELD_MUL, EC_R_NOT_INITIALIZED);

        return 0;

    }

    return BN_mod_mul_montgomery(r, a, b, group->field_data1, ctx);

}

int ec_GFp_mont_field_sqr(const EC_GROUP *group, BIGNUM *r, const BIGNUM *a,

                          BN_CTX *ctx)

{

    if (group->field_data1 == NULL) {

        ECerr(EC_F_EC_GFP_MONT_FIELD_SQR, EC_R_NOT_INITIALIZED);

        return 0;

    }

    return BN_mod_mul_montgomery(r, a, a, group->field_data1, ctx);

}

int ec_GFp_mont_field_encode(const EC_GROUP *group, BIGNUM *r,

                             const BIGNUM *a, BN_CTX *ctx)

{

    if (group->field_data1 == NULL) {

        ECerr(EC_F_EC_GFP_MONT_FIELD_ENCODE, EC_R_NOT_INITIALIZED);

        return 0;

    }

    return BN_to_montgomery(r, a, (BN_MONT_CTX *)group->field_data1, ctx);

}

int ec_GFp_mont_field_decode(const EC_GROUP *group, BIGNUM *r,

                             const BIGNUM *a, BN_CTX *ctx)

{

    if (group->field_data1 == NULL) {

        ECerr(EC_F_EC_GFP_MONT_FIELD_DECODE, EC_R_NOT_INITIALIZED);

        return 0;

    }

    return BN_from_montgomery(r, a, group->field_data1, ctx);

}

int ec_GFp_mont_field_set_to_one(const EC_GROUP *group, BIGNUM *r,

                                 BN_CTX *ctx)

{

    if (group->field_data2 == NULL) {

        ECerr(EC_F_EC_GFP_MONT_FIELD_SET_TO_ONE, EC_R_NOT_INITIALIZED);

        return 0;

    }

    if (!BN_copy(r, group->field_data2))

        return 0;

    return 1;

}