455 lines
11 KiB
C
455 lines
11 KiB
C
/* crypto/ecdsa/ecs_ossl.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 "ecdsa.h"
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#include <openssl/err.h>
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#include <openssl/obj_mac.h>
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static ECDSA_SIG *ecdsa_do_sign(const unsigned char *dgst, int dlen,
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EC_KEY *eckey);
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static int ecdsa_sign_setup(EC_KEY *eckey, BN_CTX *ctx_in, BIGNUM **kinvp,
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BIGNUM **rp);
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static int ecdsa_do_verify(const unsigned char *dgst, int dgst_len,
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ECDSA_SIG *sig, EC_KEY *eckey);
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static ECDSA_METHOD openssl_ecdsa_meth = {
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"OpenSSL ECDSA method",
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ecdsa_do_sign,
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ecdsa_sign_setup,
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ecdsa_do_verify,
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#if 0
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NULL, /* init */
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NULL, /* finish */
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#endif
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0, /* flags */
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NULL /* app_data */
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};
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const ECDSA_METHOD *ECDSA_OpenSSL(void)
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{
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return &openssl_ecdsa_meth;
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}
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static int ecdsa_sign_setup(EC_KEY *eckey, BN_CTX *ctx_in, BIGNUM **kinvp,
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BIGNUM **rp)
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{
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BN_CTX *ctx = NULL;
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BIGNUM k,*kinv=NULL,*r=NULL,*order=NULL,*X=NULL;
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EC_POINT *tmp_point=NULL;
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int ret = 0;
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if (!eckey || !eckey->group || !eckey->pub_key || !eckey->priv_key)
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{
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ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP, ERR_R_PASSED_NULL_PARAMETER);
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return 0;
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}
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BN_init(&k);
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if (ctx_in == NULL)
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{
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if ((ctx=BN_CTX_new()) == NULL)
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{
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ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP, ERR_R_MALLOC_FAILURE);
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goto err;
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}
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}
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else
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ctx=ctx_in;
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if ((r = BN_new()) == NULL)
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{
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ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP, ERR_R_BN_LIB);
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goto err;
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}
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if ((order = BN_new()) == NULL)
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{
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ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP, ERR_R_BN_LIB);
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goto err;
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}
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if ((X = BN_new()) == NULL)
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{
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ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP, ERR_R_BN_LIB);
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goto err;
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}
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if ((tmp_point = EC_POINT_new(eckey->group)) == NULL)
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{
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ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP, ERR_R_EC_LIB);
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goto err;
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}
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if (!EC_GROUP_get_order(eckey->group,order,ctx))
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{
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ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP, ERR_R_EC_LIB);
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goto err;
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}
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do
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{
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/* get random k */
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do
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if (!BN_rand_range(&k,order))
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{
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ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP,
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ECDSA_R_RANDOM_NUMBER_GENERATION_FAILED);
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goto err;
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}
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while (BN_is_zero(&k));
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/* compute r the x-coordinate of generator * k */
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if (!EC_POINT_mul(eckey->group, tmp_point, &k, NULL, NULL, ctx))
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{
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ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP, ERR_R_EC_LIB);
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goto err;
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}
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if (EC_METHOD_get_field_type(EC_GROUP_method_of(eckey->group))
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== NID_X9_62_prime_field)
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{
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if (!EC_POINT_get_affine_coordinates_GFp(eckey->group,
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tmp_point, X, NULL, ctx))
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{
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ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP,
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ERR_R_EC_LIB);
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goto err;
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}
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}
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else /* NID_X9_62_characteristic_two_field */
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{
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if (!EC_POINT_get_affine_coordinates_GF2m(eckey->group,
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tmp_point, X, NULL, ctx))
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{
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ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP,
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ERR_R_EC_LIB);
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goto err;
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}
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}
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if (!BN_nnmod(r,X,order,ctx))
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{
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ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP, ERR_R_BN_LIB);
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goto err;
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}
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}
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while (BN_is_zero(r));
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/* compute the inverse of k */
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if ((kinv = BN_mod_inverse(NULL,&k,order,ctx)) == NULL)
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{
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ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP, ERR_R_BN_LIB);
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goto err;
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}
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if (*rp == NULL)
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BN_clear_free(*rp);
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*rp = r;
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if (*kinvp == NULL)
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BN_clear_free(*kinvp);
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*kinvp = kinv;
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kinv = NULL;
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ret = 1;
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err:
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if (!ret)
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{
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if (kinv != NULL) BN_clear_free(kinv);
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if (r != NULL) BN_clear_free(r);
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}
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if (ctx_in == NULL)
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BN_CTX_free(ctx);
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if (kinv != NULL)
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BN_clear_free(kinv);
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if (order != NULL)
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BN_clear_free(order);
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if (tmp_point != NULL)
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EC_POINT_free(tmp_point);
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if (X) BN_clear_free(X);
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BN_clear_free(&k);
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return(ret);
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}
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static ECDSA_SIG *ecdsa_do_sign(const unsigned char *dgst, int dgst_len,
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EC_KEY *eckey)
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{
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BIGNUM *kinv=NULL,*r=NULL,*s=NULL,*m=NULL,*tmp=NULL,*order=NULL;
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BIGNUM xr;
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BN_CTX *ctx=NULL;
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ECDSA_SIG *ret=NULL;
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ECDSA_DATA *ecdsa;
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BN_init(&xr);
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ecdsa = ecdsa_check(eckey);
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if (!eckey || !eckey->group || !eckey->pub_key || !eckey->priv_key
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|| !ecdsa)
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{
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ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_PASSED_NULL_PARAMETER);
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goto err;
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}
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if ((ctx = BN_CTX_new()) == NULL || (order = BN_new()) == NULL ||
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(tmp = BN_new()) == NULL || (m = BN_new()) == NULL ||
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(s = BN_new()) == NULL )
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{
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ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_MALLOC_FAILURE);
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goto err;
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}
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if (!EC_GROUP_get_order(eckey->group,order,ctx))
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{
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ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_EC_LIB);
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goto err;
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}
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if (dgst_len > BN_num_bytes(order))
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{
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ECDSAerr(ECDSA_F_ECDSA_DO_SIGN,
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ECDSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE);
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goto err;
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}
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if (BN_bin2bn(dgst,dgst_len,m) == NULL)
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{
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ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_BN_LIB);
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goto err;
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}
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do
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{
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if (ecdsa->kinv == NULL || ecdsa->r == NULL)
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{
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if (!ECDSA_sign_setup(eckey,ctx,&kinv,&r))
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{
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ECDSAerr(ECDSA_F_ECDSA_DO_SIGN,
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ERR_R_ECDSA_LIB);
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goto err;
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}
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}
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else
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{
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kinv = ecdsa->kinv;
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ecdsa->kinv = NULL;
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r = ecdsa->r;
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ecdsa->r = NULL;
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}
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if (!BN_mod_mul(tmp,eckey->priv_key,r,order,ctx))
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{
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ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_BN_LIB);
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goto err;
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}
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if (!BN_add(s,tmp,m))
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{
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ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_BN_LIB);
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goto err;
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}
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if (BN_cmp(s,order) > 0)
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BN_sub(s,s,order);
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if (!BN_mod_mul(s,s,kinv,order,ctx))
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{
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ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_BN_LIB);
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goto err;
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}
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}
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while (BN_is_zero(s));
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if ((ret = ECDSA_SIG_new()) == NULL)
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{
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ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_MALLOC_FAILURE);
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goto err;
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}
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if (BN_copy(ret->r, r) == NULL || BN_copy(ret->s, s) == NULL)
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{
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ECDSA_SIG_free(ret);
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ret = NULL;
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ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_BN_LIB);
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}
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err:
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if (r)
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BN_clear_free(r);
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if (s)
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BN_clear_free(s);
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if (ctx)
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BN_CTX_free(ctx);
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if (m)
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BN_clear_free(m);
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if (tmp)
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BN_clear_free(tmp);
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if (order)
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BN_clear_free(order);
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if (kinv)
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BN_clear_free(kinv);
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return(ret);
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}
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static int ecdsa_do_verify(const unsigned char *dgst, int dgst_len,
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ECDSA_SIG *sig, EC_KEY *eckey)
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{
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BN_CTX *ctx;
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BIGNUM *order=NULL,*u1=NULL,*u2=NULL,*m=NULL,*X=NULL;
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EC_POINT *point=NULL;
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int ret = -1;
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if (!eckey || !eckey->group || !eckey->pub_key || !sig)
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{
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ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ECDSA_R_MISSING_PARAMETERS);
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return -1;
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}
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if ((ctx = BN_CTX_new()) == NULL || (order = BN_new()) == NULL ||
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(u1 = BN_new()) == NULL || (u2 = BN_new()) == NULL ||
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(m = BN_new()) == NULL || (X = BN_new()) == NULL)
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{
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ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_MALLOC_FAILURE);
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goto err;
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}
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if (!EC_GROUP_get_order(eckey->group, order, ctx))
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{
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ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_BN_LIB);
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goto err;
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}
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if (BN_is_zero(sig->r) || BN_get_sign(sig->r) ||
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BN_ucmp(sig->r, order) >= 0)
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{
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ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ECDSA_R_BAD_SIGNATURE);
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ret = 0;
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goto err;
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}
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if (BN_is_zero(sig->s) || BN_get_sign(sig->s) ||
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BN_ucmp(sig->s, order) >= 0)
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{
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ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ECDSA_R_BAD_SIGNATURE);
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ret = 0;
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goto err;
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}
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/* calculate tmp1 = inv(S) mod order */
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if ((BN_mod_inverse(u2,sig->s,order,ctx)) == NULL)
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{
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ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_BN_LIB);
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goto err;
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}
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/* digest -> m */
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if (BN_bin2bn(dgst,dgst_len,m) == NULL)
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{
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ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_BN_LIB);
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goto err;
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}
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/* u1 = m * tmp mod order */
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if (!BN_mod_mul(u1,m,u2,order,ctx))
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{
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ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_BN_LIB);
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goto err;
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}
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/* u2 = r * w mod q */
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if (!BN_mod_mul(u2,sig->r,u2,order,ctx))
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{
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ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_BN_LIB);
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goto err;
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}
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if ((point = EC_POINT_new(eckey->group)) == NULL)
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{
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ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_MALLOC_FAILURE);
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goto err;
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}
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if (!EC_POINT_mul(eckey->group, point, u1, eckey->pub_key, u2, ctx))
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{
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ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_EC_LIB);
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goto err;
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}
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if (EC_METHOD_get_field_type(EC_GROUP_method_of(eckey->group))
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== NID_X9_62_prime_field)
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{
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if (!EC_POINT_get_affine_coordinates_GFp(eckey->group,
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point, X, NULL, ctx))
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{
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ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP, ERR_R_EC_LIB);
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goto err;
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}
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}
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else /* NID_X9_62_characteristic_two_field */
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{
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if (!EC_POINT_get_affine_coordinates_GF2m(eckey->group,
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point, X, NULL, ctx))
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{
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ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP, ERR_R_EC_LIB);
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goto err;
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}
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}
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if (!BN_nnmod(u1,X,order,ctx))
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{
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ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_BN_LIB);
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goto err;
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}
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/* is now in u1. If the signature is correct, it will be
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* equal to R. */
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ret = (BN_ucmp(u1,sig->r) == 0);
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err:
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if (ctx)
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BN_CTX_free(ctx);
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if (u1)
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BN_clear_free(u1);
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if (u2)
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BN_clear_free(u2);
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if (m)
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BN_clear_free(m);
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if (X)
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BN_clear_free(X);
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if (order)
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BN_clear_free(order);
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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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