openssl/crypto/ec/ec_check.c
Matt Caswell cb9f1bc1d1 EC_POINT_is_on_curve does not return a boolean
The function EC_POINT_is_on_curve does not return a boolean value.
It returns 1 if the point is on the curve, 0 if it is not, and -1
on error. Many usages within OpenSSL were incorrectly using this
function and therefore not correctly handling error conditions.

With thanks to the Open Crypto Audit Project for reporting this issue.

Reviewed-by: Kurt Roeckx <kurt@openssl.org>
(cherry picked from commit 68886be7e2)

Conflicts:
	crypto/ec/ec2_oct.c
	crypto/ec/ecp_oct.c
	crypto/ec/ectest.c
2015-06-10 10:57:05 +01:00

120 lines
4.2 KiB
C

/* crypto/ec/ec_check.c */
/* ====================================================================
* Copyright (c) 1998-2002 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).
*
*/
#include "ec_lcl.h"
#include <openssl/err.h>
int EC_GROUP_check(const EC_GROUP *group, BN_CTX *ctx)
{
int ret = 0;
BIGNUM *order;
BN_CTX *new_ctx = NULL;
EC_POINT *point = NULL;
if (ctx == NULL) {
ctx = new_ctx = BN_CTX_new();
if (ctx == NULL) {
ECerr(EC_F_EC_GROUP_CHECK, ERR_R_MALLOC_FAILURE);
goto err;
}
}
BN_CTX_start(ctx);
if ((order = BN_CTX_get(ctx)) == NULL)
goto err;
/* check the discriminant */
if (!EC_GROUP_check_discriminant(group, ctx)) {
ECerr(EC_F_EC_GROUP_CHECK, EC_R_DISCRIMINANT_IS_ZERO);
goto err;
}
/* check the generator */
if (group->generator == NULL) {
ECerr(EC_F_EC_GROUP_CHECK, EC_R_UNDEFINED_GENERATOR);
goto err;
}
if (EC_POINT_is_on_curve(group, group->generator, ctx) <= 0) {
ECerr(EC_F_EC_GROUP_CHECK, EC_R_POINT_IS_NOT_ON_CURVE);
goto err;
}
/* check the order of the generator */
if ((point = EC_POINT_new(group)) == NULL)
goto err;
if (!EC_GROUP_get_order(group, order, ctx))
goto err;
if (BN_is_zero(order)) {
ECerr(EC_F_EC_GROUP_CHECK, 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)) {
ECerr(EC_F_EC_GROUP_CHECK, EC_R_INVALID_GROUP_ORDER);
goto err;
}
ret = 1;
err:
if (ctx != NULL)
BN_CTX_end(ctx);
if (new_ctx != NULL)
BN_CTX_free(new_ctx);
if (point)
EC_POINT_free(point);
return ret;
}