473 lines
12 KiB
C
473 lines
12 KiB
C
/* crypto/ecdsa/ecs_ossl.c */
|
|
/*
|
|
* Written by Nils Larsch for the OpenSSL project
|
|
*/
|
|
/* ====================================================================
|
|
* Copyright (c) 1998-2004 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 "ecs_locl.h"
|
|
#include <openssl/err.h>
|
|
#include <openssl/obj_mac.h>
|
|
#include <openssl/bn.h>
|
|
|
|
static ECDSA_SIG *ecdsa_do_sign(const unsigned char *dgst, int dlen,
|
|
const BIGNUM *, const BIGNUM *, EC_KEY *eckey);
|
|
static int ecdsa_sign_setup(EC_KEY *eckey, BN_CTX *ctx_in, BIGNUM **kinvp,
|
|
BIGNUM **rp);
|
|
static int ecdsa_do_verify(const unsigned char *dgst, int dgst_len,
|
|
const ECDSA_SIG *sig, EC_KEY *eckey);
|
|
|
|
static ECDSA_METHOD openssl_ecdsa_meth = {
|
|
"OpenSSL ECDSA method",
|
|
ecdsa_do_sign,
|
|
ecdsa_sign_setup,
|
|
ecdsa_do_verify,
|
|
#if 0
|
|
NULL, /* init */
|
|
NULL, /* finish */
|
|
#endif
|
|
0, /* flags */
|
|
NULL /* app_data */
|
|
};
|
|
|
|
const ECDSA_METHOD *ECDSA_OpenSSL(void)
|
|
{
|
|
return &openssl_ecdsa_meth;
|
|
}
|
|
|
|
static int ecdsa_sign_setup(EC_KEY *eckey, BN_CTX *ctx_in, BIGNUM **kinvp,
|
|
BIGNUM **rp)
|
|
{
|
|
BN_CTX *ctx = NULL;
|
|
BIGNUM *k = NULL, *r = NULL, *order = NULL, *X = NULL;
|
|
EC_POINT *tmp_point=NULL;
|
|
const EC_GROUP *group;
|
|
int ret = 0;
|
|
|
|
if (eckey == NULL || (group = EC_KEY_get0_group(eckey)) == NULL)
|
|
{
|
|
ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP, ERR_R_PASSED_NULL_PARAMETER);
|
|
return 0;
|
|
}
|
|
|
|
if (ctx_in == NULL)
|
|
{
|
|
if ((ctx = BN_CTX_new()) == NULL)
|
|
{
|
|
ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP,ERR_R_MALLOC_FAILURE);
|
|
return 0;
|
|
}
|
|
}
|
|
else
|
|
ctx = ctx_in;
|
|
|
|
k = BN_new(); /* this value is later returned in *kinvp */
|
|
r = BN_new(); /* this value is later returned in *rp */
|
|
order = BN_new();
|
|
X = BN_new();
|
|
if (!k || !r || !order || !X)
|
|
{
|
|
ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP, ERR_R_MALLOC_FAILURE);
|
|
goto err;
|
|
}
|
|
if ((tmp_point = EC_POINT_new(group)) == NULL)
|
|
{
|
|
ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP, ERR_R_EC_LIB);
|
|
goto err;
|
|
}
|
|
if (!EC_GROUP_get_order(group, order, ctx))
|
|
{
|
|
ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP, ERR_R_EC_LIB);
|
|
goto err;
|
|
}
|
|
|
|
do
|
|
{
|
|
/* get random k */
|
|
do
|
|
if (!BN_rand_range(k, order))
|
|
{
|
|
ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP,
|
|
ECDSA_R_RANDOM_NUMBER_GENERATION_FAILED);
|
|
goto err;
|
|
}
|
|
while (BN_is_zero(k));
|
|
|
|
/* compute r the x-coordinate of generator * k */
|
|
if (!EC_POINT_mul(group, tmp_point, k, NULL, NULL, ctx))
|
|
{
|
|
ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP, ERR_R_EC_LIB);
|
|
goto err;
|
|
}
|
|
if (EC_METHOD_get_field_type(EC_GROUP_method_of(group)) == NID_X9_62_prime_field)
|
|
{
|
|
if (!EC_POINT_get_affine_coordinates_GFp(group,
|
|
tmp_point, X, NULL, ctx))
|
|
{
|
|
ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP,ERR_R_EC_LIB);
|
|
goto err;
|
|
}
|
|
}
|
|
else /* NID_X9_62_characteristic_two_field */
|
|
{
|
|
if (!EC_POINT_get_affine_coordinates_GF2m(group,
|
|
tmp_point, X, NULL, ctx))
|
|
{
|
|
ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP,ERR_R_EC_LIB);
|
|
goto err;
|
|
}
|
|
}
|
|
if (!BN_nnmod(r, X, order, ctx))
|
|
{
|
|
ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP, ERR_R_BN_LIB);
|
|
goto err;
|
|
}
|
|
}
|
|
while (BN_is_zero(r));
|
|
|
|
/* compute the inverse of k */
|
|
if (!BN_mod_inverse(k, k, order, ctx))
|
|
{
|
|
ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP, ERR_R_BN_LIB);
|
|
goto err;
|
|
}
|
|
/* clear old values if necessary */
|
|
if (*rp != NULL)
|
|
BN_clear_free(*rp);
|
|
if (*kinvp != NULL)
|
|
BN_clear_free(*kinvp);
|
|
/* save the pre-computed values */
|
|
*rp = r;
|
|
*kinvp = k;
|
|
ret = 1;
|
|
err:
|
|
if (!ret)
|
|
{
|
|
if (k != NULL) BN_clear_free(k);
|
|
if (r != NULL) BN_clear_free(r);
|
|
}
|
|
if (ctx_in == NULL)
|
|
BN_CTX_free(ctx);
|
|
if (order != NULL)
|
|
BN_free(order);
|
|
if (tmp_point != NULL)
|
|
EC_POINT_free(tmp_point);
|
|
if (X)
|
|
BN_clear_free(X);
|
|
return(ret);
|
|
}
|
|
|
|
|
|
static ECDSA_SIG *ecdsa_do_sign(const unsigned char *dgst, int dgst_len,
|
|
const BIGNUM *in_kinv, const BIGNUM *in_r, EC_KEY *eckey)
|
|
{
|
|
int ok = 0, i;
|
|
BIGNUM *kinv=NULL, *s, *m=NULL,*tmp=NULL,*order=NULL;
|
|
const BIGNUM *ckinv;
|
|
BN_CTX *ctx = NULL;
|
|
const EC_GROUP *group;
|
|
ECDSA_SIG *ret;
|
|
ECDSA_DATA *ecdsa;
|
|
const BIGNUM *priv_key;
|
|
|
|
ecdsa = ecdsa_check(eckey);
|
|
group = EC_KEY_get0_group(eckey);
|
|
priv_key = EC_KEY_get0_private_key(eckey);
|
|
|
|
if (group == NULL || priv_key == NULL || ecdsa == NULL)
|
|
{
|
|
ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_PASSED_NULL_PARAMETER);
|
|
return NULL;
|
|
}
|
|
|
|
ret = ECDSA_SIG_new();
|
|
if (!ret)
|
|
{
|
|
ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_MALLOC_FAILURE);
|
|
return NULL;
|
|
}
|
|
s = ret->s;
|
|
|
|
if ((ctx = BN_CTX_new()) == NULL || (order = BN_new()) == NULL ||
|
|
(tmp = BN_new()) == NULL || (m = BN_new()) == NULL)
|
|
{
|
|
ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_MALLOC_FAILURE);
|
|
goto err;
|
|
}
|
|
|
|
if (!EC_GROUP_get_order(group, order, ctx))
|
|
{
|
|
ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_EC_LIB);
|
|
goto err;
|
|
}
|
|
i = BN_num_bits(order);
|
|
/* Need to truncate digest if it is too long: first truncate whole
|
|
* bytes.
|
|
*/
|
|
if (8 * dgst_len > i)
|
|
dgst_len = (i + 7)/8;
|
|
if (!BN_bin2bn(dgst, dgst_len, m))
|
|
{
|
|
ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_BN_LIB);
|
|
goto err;
|
|
}
|
|
/* If still too long truncate remaining bits with a shift */
|
|
if ((8 * dgst_len > i) && !BN_rshift(m, m, 8 - (i & 0x7)))
|
|
{
|
|
ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_BN_LIB);
|
|
goto err;
|
|
}
|
|
do
|
|
{
|
|
if (in_kinv == NULL || in_r == NULL)
|
|
{
|
|
if (!ECDSA_sign_setup(eckey, ctx, &kinv, &ret->r))
|
|
{
|
|
ECDSAerr(ECDSA_F_ECDSA_DO_SIGN,ERR_R_ECDSA_LIB);
|
|
goto err;
|
|
}
|
|
ckinv = kinv;
|
|
}
|
|
else
|
|
{
|
|
ckinv = in_kinv;
|
|
if (BN_copy(ret->r, in_r) == NULL)
|
|
{
|
|
ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_MALLOC_FAILURE);
|
|
goto err;
|
|
}
|
|
}
|
|
|
|
if (!BN_mod_mul(tmp, priv_key, ret->r, order, ctx))
|
|
{
|
|
ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_BN_LIB);
|
|
goto err;
|
|
}
|
|
if (!BN_mod_add_quick(s, tmp, m, order))
|
|
{
|
|
ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_BN_LIB);
|
|
goto err;
|
|
}
|
|
if (!BN_mod_mul(s, s, ckinv, order, ctx))
|
|
{
|
|
ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_BN_LIB);
|
|
goto err;
|
|
}
|
|
if (BN_is_zero(s))
|
|
{
|
|
/* if kinv and r have been supplied by the caller
|
|
* don't to generate new kinv and r values */
|
|
if (in_kinv != NULL && in_r != NULL)
|
|
{
|
|
ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ECDSA_R_NEED_NEW_SETUP_VALUES);
|
|
goto err;
|
|
}
|
|
}
|
|
else
|
|
/* s != 0 => we have a valid signature */
|
|
break;
|
|
}
|
|
while (1);
|
|
|
|
ok = 1;
|
|
err:
|
|
if (!ok)
|
|
{
|
|
ECDSA_SIG_free(ret);
|
|
ret = NULL;
|
|
}
|
|
if (ctx)
|
|
BN_CTX_free(ctx);
|
|
if (m)
|
|
BN_clear_free(m);
|
|
if (tmp)
|
|
BN_clear_free(tmp);
|
|
if (order)
|
|
BN_free(order);
|
|
if (kinv)
|
|
BN_clear_free(kinv);
|
|
return ret;
|
|
}
|
|
|
|
static int ecdsa_do_verify(const unsigned char *dgst, int dgst_len,
|
|
const ECDSA_SIG *sig, EC_KEY *eckey)
|
|
{
|
|
int ret = -1, i;
|
|
BN_CTX *ctx;
|
|
BIGNUM *order, *u1, *u2, *m, *X;
|
|
EC_POINT *point = NULL;
|
|
const EC_GROUP *group;
|
|
const EC_POINT *pub_key;
|
|
|
|
/* check input values */
|
|
if (eckey == NULL || (group = EC_KEY_get0_group(eckey)) == NULL ||
|
|
(pub_key = EC_KEY_get0_public_key(eckey)) == NULL || sig == NULL)
|
|
{
|
|
ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ECDSA_R_MISSING_PARAMETERS);
|
|
return -1;
|
|
}
|
|
|
|
ctx = BN_CTX_new();
|
|
if (!ctx)
|
|
{
|
|
ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_MALLOC_FAILURE);
|
|
return -1;
|
|
}
|
|
BN_CTX_start(ctx);
|
|
order = BN_CTX_get(ctx);
|
|
u1 = BN_CTX_get(ctx);
|
|
u2 = BN_CTX_get(ctx);
|
|
m = BN_CTX_get(ctx);
|
|
X = BN_CTX_get(ctx);
|
|
if (!X)
|
|
{
|
|
ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_BN_LIB);
|
|
goto err;
|
|
}
|
|
|
|
if (!EC_GROUP_get_order(group, order, ctx))
|
|
{
|
|
ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_EC_LIB);
|
|
goto err;
|
|
}
|
|
|
|
if (BN_is_zero(sig->r) || BN_is_negative(sig->r) ||
|
|
BN_ucmp(sig->r, order) >= 0 || BN_is_zero(sig->s) ||
|
|
BN_is_negative(sig->s) || BN_ucmp(sig->s, order) >= 0)
|
|
{
|
|
ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ECDSA_R_BAD_SIGNATURE);
|
|
ret = 0; /* signature is invalid */
|
|
goto err;
|
|
}
|
|
/* calculate tmp1 = inv(S) mod order */
|
|
if (!BN_mod_inverse(u2, sig->s, order, ctx))
|
|
{
|
|
ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_BN_LIB);
|
|
goto err;
|
|
}
|
|
/* digest -> m */
|
|
i = BN_num_bits(order);
|
|
/* Need to truncate digest if it is too long: first truncate whole
|
|
* bytes.
|
|
*/
|
|
if (8 * dgst_len > i)
|
|
dgst_len = (i + 7)/8;
|
|
if (!BN_bin2bn(dgst, dgst_len, m))
|
|
{
|
|
ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_BN_LIB);
|
|
goto err;
|
|
}
|
|
/* If still too long truncate remaining bits with a shift */
|
|
if ((8 * dgst_len > i) && !BN_rshift(m, m, 8 - (i & 0x7)))
|
|
{
|
|
ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_BN_LIB);
|
|
goto err;
|
|
}
|
|
/* u1 = m * tmp mod order */
|
|
if (!BN_mod_mul(u1, m, u2, order, ctx))
|
|
{
|
|
ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_BN_LIB);
|
|
goto err;
|
|
}
|
|
/* u2 = r * w mod q */
|
|
if (!BN_mod_mul(u2, sig->r, u2, order, ctx))
|
|
{
|
|
ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_BN_LIB);
|
|
goto err;
|
|
}
|
|
|
|
if ((point = EC_POINT_new(group)) == NULL)
|
|
{
|
|
ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_MALLOC_FAILURE);
|
|
goto err;
|
|
}
|
|
if (!EC_POINT_mul(group, point, u1, pub_key, u2, ctx))
|
|
{
|
|
ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_EC_LIB);
|
|
goto err;
|
|
}
|
|
if (EC_METHOD_get_field_type(EC_GROUP_method_of(group)) == NID_X9_62_prime_field)
|
|
{
|
|
if (!EC_POINT_get_affine_coordinates_GFp(group,
|
|
point, X, NULL, ctx))
|
|
{
|
|
ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_EC_LIB);
|
|
goto err;
|
|
}
|
|
}
|
|
else /* NID_X9_62_characteristic_two_field */
|
|
{
|
|
if (!EC_POINT_get_affine_coordinates_GF2m(group,
|
|
point, X, NULL, ctx))
|
|
{
|
|
ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_EC_LIB);
|
|
goto err;
|
|
}
|
|
}
|
|
|
|
if (!BN_nnmod(u1, X, order, ctx))
|
|
{
|
|
ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_BN_LIB);
|
|
goto err;
|
|
}
|
|
/* if the signature is correct u1 is equal to sig->r */
|
|
ret = (BN_ucmp(u1, sig->r) == 0);
|
|
err:
|
|
BN_CTX_end(ctx);
|
|
BN_CTX_free(ctx);
|
|
if (point)
|
|
EC_POINT_free(point);
|
|
return ret;
|
|
}
|