/* crypto/ec/ecp_nist.c */

/*

 * Written by Nils Larsch for the OpenSSL project.

 */

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

 * Copyright (c) 1998-2003 The OpenSSL Project.  All rights reserved.

 *

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

 * modification, are permitted provided that the following conditions

 * are met:

 *

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

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

 *

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

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

 *    the documentation and/or other materials provided with the

 *    distribution.

 *

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

 *    software must display the following acknowledgment:

 *    "This product includes software developed by the OpenSSL Project

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

 *

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

 *    endorse or promote products derived from this software without

 *    prior written permission. For written permission, please contact

 *    openssl-core@openssl.org.

 *

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

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

 *    permission of the OpenSSL Project.

 *

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

 *    acknowledgment:

 *    "This product includes software developed by the OpenSSL Project

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

 *

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

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

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

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

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

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

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

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

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

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

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

 * OF THE POSSIBILITY OF SUCH DAMAGE.

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

 *

 * This product includes cryptographic software written by Eric Young

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

 * Hudson (tjh@cryptsoft.com).

 *

 */

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

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

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

 * and contributed to the OpenSSL project.

 */

#include <limits.h>

#include <openssl/err.h>

#include <openssl/obj_mac.h>

#include "ec_lcl.h"

#ifdef OPENSSL_FIPS

# include <openssl/fips.h>

#endif

const EC_METHOD *EC_GFp_nist_method(void)

{

    static const EC_METHOD ret = {

        EC_FLAGS_DEFAULT_OCT,

        NID_X9_62_prime_field,

        ec_GFp_simple_group_init,

        ec_GFp_simple_group_finish,

        ec_GFp_simple_group_clear_finish,

        ec_GFp_nist_group_copy,

        ec_GFp_nist_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_nist_field_mul,

        ec_GFp_nist_field_sqr,

        0 /* field_div */ ,

        0 /* field_encode */ ,

        0 /* field_decode */ ,

        0                       /* field_set_to_one */

    };

#ifdef OPENSSL_FIPS

    if (FIPS_mode())

        return fips_ec_gfp_nist_method();

#endif

    return &ret;

}

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

{

    dest->field_mod_func = src->field_mod_func;

    return ec_GFp_simple_group_copy(dest, src);

}

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

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

{

    int ret = 0;

    BN_CTX *new_ctx = NULL;

    BIGNUM *tmp_bn;

    if (ctx == NULL)

        if ((ctx = new_ctx = BN_CTX_new()) == NULL)

            return 0;

    BN_CTX_start(ctx);

    if ((tmp_bn = BN_CTX_get(ctx)) == NULL)

        goto err;

    if (BN_ucmp(BN_get0_nist_prime_192(), p) == 0)

        group->field_mod_func = BN_nist_mod_192;

    else if (BN_ucmp(BN_get0_nist_prime_224(), p) == 0)

        group->field_mod_func = BN_nist_mod_224;

    else if (BN_ucmp(BN_get0_nist_prime_256(), p) == 0)

        group->field_mod_func = BN_nist_mod_256;

    else if (BN_ucmp(BN_get0_nist_prime_384(), p) == 0)

        group->field_mod_func = BN_nist_mod_384;

    else if (BN_ucmp(BN_get0_nist_prime_521(), p) == 0)

        group->field_mod_func = BN_nist_mod_521;

    else {

        ECerr(EC_F_EC_GFP_NIST_GROUP_SET_CURVE, EC_R_NOT_A_NIST_PRIME);

        goto err;

    }

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

 err:

    BN_CTX_end(ctx);

    if (new_ctx != NULL)

        BN_CTX_free(new_ctx);

    return ret;

}

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

                          const BIGNUM *b, BN_CTX *ctx)

{

    int ret = 0;

    BN_CTX *ctx_new = NULL;

    if (!group || !r || !a || !b) {

        ECerr(EC_F_EC_GFP_NIST_FIELD_MUL, ERR_R_PASSED_NULL_PARAMETER);

        goto err;

    }

    if (!ctx)

        if ((ctx_new = ctx = BN_CTX_new()) == NULL)

            goto err;

    if (!BN_mul(r, a, b, ctx))

        goto err;

    if (!group->field_mod_func(r, r, &group->field, ctx))

        goto err;

    ret = 1;

 err:

    if (ctx_new)

        BN_CTX_free(ctx_new);

    return ret;

}

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

                          BN_CTX *ctx)

{

    int ret = 0;

    BN_CTX *ctx_new = NULL;

    if (!group || !r || !a) {

        ECerr(EC_F_EC_GFP_NIST_FIELD_SQR, EC_R_PASSED_NULL_PARAMETER);

        goto err;

    }

    if (!ctx)

        if ((ctx_new = ctx = BN_CTX_new()) == NULL)

            goto err;

    if (!BN_sqr(r, a, ctx))

        goto err;

    if (!group->field_mod_func(r, r, &group->field, ctx))

        goto err;

    ret = 1;

 err:

    if (ctx_new)

        BN_CTX_free(ctx_new);

    return ret;

}