1 /* ====================================================================
2 * Copyright (c) 1998-2002 The OpenSSL Project. All rights reserved.
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in
13 * the documentation and/or other materials provided with the
16 * 3. All advertising materials mentioning features or use of this
17 * software must display the following acknowledgment:
18 * "This product includes software developed by the OpenSSL Project
19 * for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
21 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
22 * endorse or promote products derived from this software without
23 * prior written permission. For written permission, please contact
24 * openssl-core@openssl.org.
26 * 5. Products derived from this software may not be called "OpenSSL"
27 * nor may "OpenSSL" appear in their names without prior written
28 * permission of the OpenSSL Project.
30 * 6. Redistributions of any form whatsoever must retain the following
32 * "This product includes software developed by the OpenSSL Project
33 * for use in the OpenSSL Toolkit (http://www.openssl.org/)"
35 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
36 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
37 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
38 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
39 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
40 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
41 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
42 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
43 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
44 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
45 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
46 * OF THE POSSIBILITY OF SUCH DAMAGE.
47 * ====================================================================
49 * This product includes cryptographic software written by Eric Young
50 * (eay@cryptsoft.com). This product includes software written by Tim
51 * Hudson (tjh@cryptsoft.com).
56 #include <openssl/err.h>
58 int EC_GROUP_check(const EC_GROUP *group, BN_CTX *ctx)
62 BN_CTX *new_ctx = NULL;
63 EC_POINT *point = NULL;
66 ctx = new_ctx = BN_CTX_new();
68 ECerr(EC_F_EC_GROUP_CHECK, ERR_R_MALLOC_FAILURE);
73 if ((order = BN_CTX_get(ctx)) == NULL)
76 /* check the discriminant */
77 if (!EC_GROUP_check_discriminant(group, ctx)) {
78 ECerr(EC_F_EC_GROUP_CHECK, EC_R_DISCRIMINANT_IS_ZERO);
82 /* check the generator */
83 if (group->generator == NULL) {
84 ECerr(EC_F_EC_GROUP_CHECK, EC_R_UNDEFINED_GENERATOR);
87 if (EC_POINT_is_on_curve(group, group->generator, ctx) <= 0) {
88 ECerr(EC_F_EC_GROUP_CHECK, EC_R_POINT_IS_NOT_ON_CURVE);
92 /* check the order of the generator */
93 if ((point = EC_POINT_new(group)) == NULL)
95 order = EC_GROUP_get0_order(group);
98 if (BN_is_zero(order)) {
99 ECerr(EC_F_EC_GROUP_CHECK, EC_R_UNDEFINED_ORDER);
103 if (!EC_POINT_mul(group, point, order, NULL, NULL, ctx))
105 if (!EC_POINT_is_at_infinity(group, point)) {
106 ECerr(EC_F_EC_GROUP_CHECK, EC_R_INVALID_GROUP_ORDER);
115 BN_CTX_free(new_ctx);
116 EC_POINT_free(point);