/*

 * Copyright 2002-2021 The OpenSSL Project Authors. All Rights Reserved.

 *

 * Licensed under the Apache License 2.0 (the "License").  You may not use

 * this file except in compliance with the License.  You can obtain a copy

 * in the file LICENSE in the source distribution or at

 * https://www.openssl.org/source/license.html

 */

/*

 * ECDSA low level APIs are deprecated for public use, but still ok for

 * internal use.

 */

#include "internal/deprecated.h"

#include "ec_local.h"

#include <openssl/err.h>

int EC_GROUP_check_named_curve(const EC_GROUP *group, int nist_only,

                               BN_CTX *ctx)

{

    int nid;

    BN_CTX *new_ctx = NULL;

    if (group == NULL) {

        ERR_raise(ERR_LIB_EC, ERR_R_PASSED_NULL_PARAMETER);

        return NID_undef;

    }

    if (ctx == NULL) {

        ctx = new_ctx = BN_CTX_new_ex(NULL);

        if (ctx == NULL) {

            ERR_raise(ERR_LIB_EC, ERR_R_MALLOC_FAILURE);

            return NID_undef;

        }

    }

    nid = ossl_ec_curve_nid_from_params(group, ctx);

    if (nid > 0 && nist_only && EC_curve_nid2nist(nid) == NULL)

        nid = NID_undef;

    BN_CTX_free(new_ctx);

    return nid;

}

int EC_GROUP_check(const EC_GROUP *group, BN_CTX *ctx)

{

#ifdef FIPS_MODULE

    /*

    * ECC domain parameter validation.

    * See SP800-56A R3 5.5.2 "Assurances of Domain-Parameter Validity" Part 1b.

    */

    return EC_GROUP_check_named_curve(group, 1, ctx) >= 0 ? 1 : 0;

#else

    int ret = 0;

    const BIGNUM *order;

    BN_CTX *new_ctx = NULL;

    EC_POINT *point = NULL;

    if (group == NULL || group->meth == NULL) {

        ERR_raise(ERR_LIB_EC, ERR_R_PASSED_NULL_PARAMETER);

        return 0;

    }

    /* Custom curves assumed to be correct */

    if ((group->meth->flags & EC_FLAGS_CUSTOM_CURVE) != 0)

        return 1;

    if (ctx == NULL) {

        ctx = new_ctx = BN_CTX_new();

        if (ctx == NULL) {

            ERR_raise(ERR_LIB_EC, ERR_R_MALLOC_FAILURE);

            goto err;

        }

    }

    /* check the discriminant */

    if (!EC_GROUP_check_discriminant(group, ctx)) {

        ERR_raise(ERR_LIB_EC, EC_R_DISCRIMINANT_IS_ZERO);

        goto err;

    }

    /* check the generator */

    if (group->generator == NULL) {

        ERR_raise(ERR_LIB_EC, EC_R_UNDEFINED_GENERATOR);

        goto err;

    }

    if (EC_POINT_is_on_curve(group, group->generator, ctx) <= 0) {

        ERR_raise(ERR_LIB_EC, EC_R_POINT_IS_NOT_ON_CURVE);

        goto err;

    }

    /* check the order of the generator */

    if ((point = EC_POINT_new(group)) == NULL)

        goto err;

    order = EC_GROUP_get0_order(group);

    if (order == NULL)

        goto err;

    if (BN_is_zero(order)) {

        ERR_raise(ERR_LIB_EC, EC_R_UNDEFINED_ORDER);

        goto err;

    }

    if (!EC_POINT_mul(group, point, order, NULL, NULL, ctx))

        goto err;

    if (!EC_POINT_is_at_infinity(group, point)) {

        ERR_raise(ERR_LIB_EC, EC_R_INVALID_GROUP_ORDER);

        goto err;

    }

    ret = 1;

 err:

    BN_CTX_free(new_ctx);

    EC_POINT_free(point);

    return ret;

#endif /* FIPS_MODULE */

}