2 * Copyright 2002-2016 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the OpenSSL license (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
11 #include <openssl/err.h>
13 int EC_GROUP_check(const EC_GROUP *group, BN_CTX *ctx)
17 BN_CTX *new_ctx = NULL;
18 EC_POINT *point = NULL;
20 /* Custom curves assumed to be correct */
21 if ((group->meth->flags & EC_FLAGS_CUSTOM_CURVE) != 0)
25 ctx = new_ctx = BN_CTX_new();
27 ECerr(EC_F_EC_GROUP_CHECK, ERR_R_MALLOC_FAILURE);
32 /* check the discriminant */
33 if (!EC_GROUP_check_discriminant(group, ctx)) {
34 ECerr(EC_F_EC_GROUP_CHECK, EC_R_DISCRIMINANT_IS_ZERO);
38 /* check the generator */
39 if (group->generator == NULL) {
40 ECerr(EC_F_EC_GROUP_CHECK, EC_R_UNDEFINED_GENERATOR);
43 if (EC_POINT_is_on_curve(group, group->generator, ctx) <= 0) {
44 ECerr(EC_F_EC_GROUP_CHECK, EC_R_POINT_IS_NOT_ON_CURVE);
48 /* check the order of the generator */
49 if ((point = EC_POINT_new(group)) == NULL)
51 order = EC_GROUP_get0_order(group);
54 if (BN_is_zero(order)) {
55 ECerr(EC_F_EC_GROUP_CHECK, EC_R_UNDEFINED_ORDER);
59 if (!EC_POINT_mul(group, point, order, NULL, NULL, ctx))
61 if (!EC_POINT_is_at_infinity(group, point)) {
62 ECerr(EC_F_EC_GROUP_CHECK, EC_R_INVALID_GROUP_ORDER);