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120 lines
4.2 KiB
120 lines
4.2 KiB
/* crypto/ec/ec_check.c */ |
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/* ==================================================================== |
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* Copyright (c) 1998-2002 The OpenSSL Project. All rights reserved. |
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* |
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* Redistribution and use in source and binary forms, with or without |
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* modification, are permitted provided that the following conditions |
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* are met: |
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* |
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* 1. Redistributions of source code must retain the above copyright |
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* notice, this list of conditions and the following disclaimer. |
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* |
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* 2. Redistributions in binary form must reproduce the above copyright |
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* notice, this list of conditions and the following disclaimer in |
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* the documentation and/or other materials provided with the |
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* distribution. |
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* |
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* 3. All advertising materials mentioning features or use of this |
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* software must display the following acknowledgment: |
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* "This product includes software developed by the OpenSSL Project |
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* for use in the OpenSSL Toolkit. (http://www.openssl.org/)" |
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* |
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* 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to |
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* endorse or promote products derived from this software without |
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* prior written permission. For written permission, please contact |
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* openssl-core@openssl.org. |
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* |
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* 5. Products derived from this software may not be called "OpenSSL" |
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* nor may "OpenSSL" appear in their names without prior written |
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* permission of the OpenSSL Project. |
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* |
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* 6. Redistributions of any form whatsoever must retain the following |
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* acknowledgment: |
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* "This product includes software developed by the OpenSSL Project |
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* for use in the OpenSSL Toolkit (http://www.openssl.org/)" |
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* |
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* THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY |
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* EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
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* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR |
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* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
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* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, |
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* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED |
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* OF THE POSSIBILITY OF SUCH DAMAGE. |
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* ==================================================================== |
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* |
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* This product includes cryptographic software written by Eric Young |
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* (eay@cryptsoft.com). This product includes software written by Tim |
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* Hudson (tjh@cryptsoft.com). |
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* |
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*/ |
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#include "ec_lcl.h" |
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#include <openssl/err.h> |
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int EC_GROUP_check(const EC_GROUP *group, BN_CTX *ctx) |
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{ |
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int ret = 0; |
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BIGNUM *order; |
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BN_CTX *new_ctx = NULL; |
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EC_POINT *point = NULL; |
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if (ctx == NULL) { |
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ctx = new_ctx = BN_CTX_new(); |
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if (ctx == NULL) { |
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ECerr(EC_F_EC_GROUP_CHECK, ERR_R_MALLOC_FAILURE); |
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goto err; |
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} |
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} |
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BN_CTX_start(ctx); |
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if ((order = BN_CTX_get(ctx)) == NULL) |
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goto err; |
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/* check the discriminant */ |
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if (!EC_GROUP_check_discriminant(group, ctx)) { |
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ECerr(EC_F_EC_GROUP_CHECK, EC_R_DISCRIMINANT_IS_ZERO); |
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goto err; |
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} |
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/* check the generator */ |
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if (group->generator == NULL) { |
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ECerr(EC_F_EC_GROUP_CHECK, EC_R_UNDEFINED_GENERATOR); |
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goto err; |
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} |
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if (EC_POINT_is_on_curve(group, group->generator, ctx) <= 0) { |
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ECerr(EC_F_EC_GROUP_CHECK, EC_R_POINT_IS_NOT_ON_CURVE); |
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goto err; |
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} |
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/* check the order of the generator */ |
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if ((point = EC_POINT_new(group)) == NULL) |
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goto err; |
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if (!EC_GROUP_get_order(group, order, ctx)) |
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goto err; |
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if (BN_is_zero(order)) { |
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ECerr(EC_F_EC_GROUP_CHECK, EC_R_UNDEFINED_ORDER); |
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goto err; |
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} |
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if (!EC_POINT_mul(group, point, order, NULL, NULL, ctx)) |
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goto err; |
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if (!EC_POINT_is_at_infinity(group, point)) { |
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ECerr(EC_F_EC_GROUP_CHECK, EC_R_INVALID_GROUP_ORDER); |
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goto err; |
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} |
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ret = 1; |
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err: |
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if (ctx != NULL) |
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BN_CTX_end(ctx); |
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if (new_ctx != NULL) |
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BN_CTX_free(new_ctx); |
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if (point) |
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EC_POINT_free(point); |
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return ret; |
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}
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