/*
- * Copyright 2002-2017 The OpenSSL Project Authors. All Rights Reserved.
+ * Copyright 2002-2018 The OpenSSL Project Authors. All Rights Reserved.
*
- * Licensed under the OpenSSL license (the "License"). You may not use
+ * Licensed under the Apache License 2.0 (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
#include <string.h>
#include <openssl/err.h>
#include <openssl/obj_mac.h>
-#include <openssl/bn.h>
#include <openssl/rand.h>
-#include <openssl/ec.h>
+#include "internal/bn_int.h"
#include "ec_lcl.h"
+int ossl_ecdsa_sign_setup(EC_KEY *eckey, BN_CTX *ctx_in, BIGNUM **kinvp,
+ BIGNUM **rp)
+{
+ if (eckey->group->meth->ecdsa_sign_setup == NULL) {
+ ECerr(EC_F_OSSL_ECDSA_SIGN_SETUP, EC_R_CURVE_DOES_NOT_SUPPORT_ECDSA);
+ return 0;
+ }
+
+ return eckey->group->meth->ecdsa_sign_setup(eckey, ctx_in, kinvp, rp);
+}
+
+ECDSA_SIG *ossl_ecdsa_sign_sig(const unsigned char *dgst, int dgst_len,
+ const BIGNUM *in_kinv, const BIGNUM *in_r,
+ EC_KEY *eckey)
+{
+ if (eckey->group->meth->ecdsa_sign_sig == NULL) {
+ ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, EC_R_CURVE_DOES_NOT_SUPPORT_ECDSA);
+ return NULL;
+ }
+
+ return eckey->group->meth->ecdsa_sign_sig(dgst, dgst_len,
+ in_kinv, in_r, eckey);
+}
+
+int ossl_ecdsa_verify_sig(const unsigned char *dgst, int dgst_len,
+ const ECDSA_SIG *sig, EC_KEY *eckey)
+{
+ if (eckey->group->meth->ecdsa_verify_sig == NULL) {
+ ECerr(EC_F_OSSL_ECDSA_VERIFY_SIG, EC_R_CURVE_DOES_NOT_SUPPORT_ECDSA);
+ return 0;
+ }
+
+ return eckey->group->meth->ecdsa_verify_sig(dgst, dgst_len, sig, eckey);
+}
+
int ossl_ecdsa_sign(int type, const unsigned char *dgst, int dlen,
unsigned char *sig, unsigned int *siglen,
const BIGNUM *kinv, const BIGNUM *r, EC_KEY *eckey)
const EC_GROUP *group;
int ret = 0;
int order_bits;
+ const BIGNUM *priv_key;
if (eckey == NULL || (group = EC_KEY_get0_group(eckey)) == NULL) {
ECerr(EC_F_ECDSA_SIGN_SETUP, ERR_R_PASSED_NULL_PARAMETER);
return 0;
}
+ if ((priv_key = EC_KEY_get0_private_key(eckey)) == NULL) {
+ ECerr(EC_F_ECDSA_SIGN_SETUP, EC_R_MISSING_PRIVATE_KEY);
+ return 0;
+ }
if (!EC_KEY_can_sign(eckey)) {
ECerr(EC_F_ECDSA_SIGN_SETUP, EC_R_CURVE_DOES_NOT_SUPPORT_SIGNING);
return 0;
}
- if (ctx_in == NULL) {
- if ((ctx = BN_CTX_new()) == NULL) {
+ if ((ctx = ctx_in) == NULL) {
+ if ((ctx = BN_CTX_new_ex(eckey->libctx)) == NULL) {
ECerr(EC_F_ECDSA_SIGN_SETUP, ERR_R_MALLOC_FAILURE);
return 0;
}
- } else
- ctx = ctx_in;
+ }
- k = BN_new(); /* this value is later returned in *kinvp */
+ k = BN_secure_new(); /* this value is later returned in *kinvp */
r = BN_new(); /* this value is later returned in *rp */
X = BN_new();
if (k == NULL || r == NULL || X == NULL) {
goto err;
}
order = EC_GROUP_get0_order(group);
- if (order == NULL) {
- ECerr(EC_F_ECDSA_SIGN_SETUP, ERR_R_EC_LIB);
- goto err;
- }
/* Preallocate space */
order_bits = BN_num_bits(order);
do {
/* get random k */
- do
+ do {
if (dgst != NULL) {
- if (!BN_generate_dsa_nonce
- (k, order, EC_KEY_get0_private_key(eckey), dgst, dlen,
- ctx)) {
+ if (!BN_generate_dsa_nonce(k, order, priv_key,
+ dgst, dlen, ctx)) {
ECerr(EC_F_ECDSA_SIGN_SETUP,
- EC_R_RANDOM_NUMBER_GENERATION_FAILED);
+ EC_R_RANDOM_NUMBER_GENERATION_FAILED);
goto err;
}
} else {
- if (!BN_priv_rand_range(k, order)) {
+ if (!BN_priv_rand_range_ex(k, order, ctx)) {
ECerr(EC_F_ECDSA_SIGN_SETUP,
- EC_R_RANDOM_NUMBER_GENERATION_FAILED);
+ EC_R_RANDOM_NUMBER_GENERATION_FAILED);
goto err;
}
}
- while (BN_is_zero(k));
-
- /*
- * We do not want timing information to leak the length of k, so we
- * compute G*k using an equivalent scalar of fixed bit-length.
- *
- * We unconditionally perform both of these additions to prevent a
- * small timing information leakage. We then choose the sum that is
- * one bit longer than the order. This guarantees the code
- * path used in the constant time implementations elsewhere.
- *
- * TODO: revisit the BN_copy aiming for a memory access agnostic
- * conditional copy.
- */
- if (!BN_add(r, k, order)
- || !BN_add(X, r, order)
- || !BN_copy(k, BN_num_bits(r) > order_bits ? r : X))
- 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)) {
ECerr(EC_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)) {
- ECerr(EC_F_ECDSA_SIGN_SETUP, ERR_R_EC_LIB);
- goto err;
- }
- }
-#ifndef OPENSSL_NO_EC2M
- else { /* NID_X9_62_characteristic_two_field */
- if (!EC_POINT_get_affine_coordinates_GF2m(group,
- tmp_point, X, NULL,
- ctx)) {
- ECerr(EC_F_ECDSA_SIGN_SETUP, ERR_R_EC_LIB);
- goto err;
- }
+ if (!EC_POINT_get_affine_coordinates(group, tmp_point, X, NULL, ctx)) {
+ ECerr(EC_F_ECDSA_SIGN_SETUP, ERR_R_EC_LIB);
+ goto err;
}
-#endif
+
if (!BN_nnmod(r, X, order, ctx)) {
ECerr(EC_F_ECDSA_SIGN_SETUP, ERR_R_BN_LIB);
goto err;
}
- }
- while (BN_is_zero(r));
+ } while (BN_is_zero(r));
/* compute the inverse of k */
- if (EC_GROUP_get_mont_data(group) != NULL) {
- /*
- * We want inverse in constant time, therefore we utilize the fact
- * order must be prime and use Fermat's Little Theorem instead.
- */
- if (!BN_set_word(X, 2)) {
- ECerr(EC_F_ECDSA_SIGN_SETUP, ERR_R_BN_LIB);
- goto err;
- }
- if (!BN_mod_sub(X, order, X, order, ctx)) {
- ECerr(EC_F_ECDSA_SIGN_SETUP, ERR_R_BN_LIB);
- goto err;
- }
- BN_set_flags(X, BN_FLG_CONSTTIME);
- if (!BN_mod_exp_mont_consttime
- (k, k, X, order, ctx, EC_GROUP_get_mont_data(group))) {
- ECerr(EC_F_ECDSA_SIGN_SETUP, ERR_R_BN_LIB);
- goto err;
- }
- } else {
- if (!BN_mod_inverse(k, k, order, ctx)) {
- ECerr(EC_F_ECDSA_SIGN_SETUP, ERR_R_BN_LIB);
- goto err;
- }
+ if (!ec_group_do_inverse_ord(group, k, k, ctx)) {
+ ECerr(EC_F_ECDSA_SIGN_SETUP, ERR_R_BN_LIB);
+ goto err;
}
/* clear old values if necessary */
return ret;
}
-int ossl_ecdsa_sign_setup(EC_KEY *eckey, BN_CTX *ctx_in, BIGNUM **kinvp,
- BIGNUM **rp)
+int ecdsa_simple_sign_setup(EC_KEY *eckey, BN_CTX *ctx_in, BIGNUM **kinvp,
+ BIGNUM **rp)
{
return ecdsa_sign_setup(eckey, ctx_in, kinvp, rp, NULL, 0);
}
-ECDSA_SIG *ossl_ecdsa_sign_sig(const unsigned char *dgst, int dgst_len,
- const BIGNUM *in_kinv, const BIGNUM *in_r,
- EC_KEY *eckey)
+ECDSA_SIG *ecdsa_simple_sign_sig(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;
+ BIGNUM *kinv = NULL, *s, *m = NULL;
const BIGNUM *order, *ckinv;
BN_CTX *ctx = NULL;
const EC_GROUP *group;
group = EC_KEY_get0_group(eckey);
priv_key = EC_KEY_get0_private_key(eckey);
- if (group == NULL || priv_key == NULL) {
- ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, ERR_R_PASSED_NULL_PARAMETER);
+ if (group == NULL) {
+ ECerr(EC_F_ECDSA_SIMPLE_SIGN_SIG, ERR_R_PASSED_NULL_PARAMETER);
+ return NULL;
+ }
+ if (priv_key == NULL) {
+ ECerr(EC_F_ECDSA_SIMPLE_SIGN_SIG, EC_R_MISSING_PRIVATE_KEY);
return NULL;
}
if (!EC_KEY_can_sign(eckey)) {
- ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, EC_R_CURVE_DOES_NOT_SUPPORT_SIGNING);
+ ECerr(EC_F_ECDSA_SIMPLE_SIGN_SIG, EC_R_CURVE_DOES_NOT_SUPPORT_SIGNING);
return NULL;
}
ret = ECDSA_SIG_new();
if (ret == NULL) {
- ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, ERR_R_MALLOC_FAILURE);
+ ECerr(EC_F_ECDSA_SIMPLE_SIGN_SIG, ERR_R_MALLOC_FAILURE);
return NULL;
}
ret->r = BN_new();
ret->s = BN_new();
if (ret->r == NULL || ret->s == NULL) {
- ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, ERR_R_MALLOC_FAILURE);
+ ECerr(EC_F_ECDSA_SIMPLE_SIGN_SIG, ERR_R_MALLOC_FAILURE);
goto err;
}
s = ret->s;
- if ((ctx = BN_CTX_new()) == NULL ||
- (tmp = BN_new()) == NULL || (m = BN_new()) == NULL) {
- ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, ERR_R_MALLOC_FAILURE);
+ if ((ctx = BN_CTX_new_ex(eckey->libctx)) == NULL
+ || (m = BN_new()) == NULL) {
+ ECerr(EC_F_ECDSA_SIMPLE_SIGN_SIG, ERR_R_MALLOC_FAILURE);
goto err;
}
order = EC_GROUP_get0_order(group);
- if (order == NULL) {
- ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, 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)) {
- ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, ERR_R_BN_LIB);
+ ECerr(EC_F_ECDSA_SIMPLE_SIGN_SIG, ERR_R_BN_LIB);
goto err;
}
- /* If still too long truncate remaining bits with a shift */
+ /* If still too long, truncate remaining bits with a shift */
if ((8 * dgst_len > i) && !BN_rshift(m, m, 8 - (i & 0x7))) {
- ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, ERR_R_BN_LIB);
+ ECerr(EC_F_ECDSA_SIMPLE_SIGN_SIG, ERR_R_BN_LIB);
goto err;
}
do {
if (in_kinv == NULL || in_r == NULL) {
if (!ecdsa_sign_setup(eckey, ctx, &kinv, &ret->r, dgst, dgst_len)) {
- ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, ERR_R_ECDSA_LIB);
+ ECerr(EC_F_ECDSA_SIMPLE_SIGN_SIG, ERR_R_ECDSA_LIB);
goto err;
}
ckinv = kinv;
} else {
ckinv = in_kinv;
if (BN_copy(ret->r, in_r) == NULL) {
- ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, ERR_R_MALLOC_FAILURE);
+ ECerr(EC_F_ECDSA_SIMPLE_SIGN_SIG, ERR_R_MALLOC_FAILURE);
goto err;
}
}
- if (!BN_mod_mul(tmp, priv_key, ret->r, order, ctx)) {
- ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, ERR_R_BN_LIB);
+ /*
+ * With only one multiplicant being in Montgomery domain
+ * multiplication yields real result without post-conversion.
+ * Also note that all operations but last are performed with
+ * zero-padded vectors. Last operation, BN_mod_mul_montgomery
+ * below, returns user-visible value with removed zero padding.
+ */
+ if (!bn_to_mont_fixed_top(s, ret->r, group->mont_data, ctx)
+ || !bn_mul_mont_fixed_top(s, s, priv_key, group->mont_data, ctx)) {
+ ECerr(EC_F_ECDSA_SIMPLE_SIGN_SIG, ERR_R_BN_LIB);
goto err;
}
- if (!BN_mod_add_quick(s, tmp, m, order)) {
- ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, ERR_R_BN_LIB);
+ if (!bn_mod_add_fixed_top(s, s, m, order)) {
+ ECerr(EC_F_ECDSA_SIMPLE_SIGN_SIG, ERR_R_BN_LIB);
goto err;
}
- if (!BN_mod_mul(s, s, ckinv, order, ctx)) {
- ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, ERR_R_BN_LIB);
+ /*
+ * |s| can still be larger than modulus, because |m| can be. In
+ * such case we count on Montgomery reduction to tie it up.
+ */
+ if (!bn_to_mont_fixed_top(s, s, group->mont_data, ctx)
+ || !BN_mod_mul_montgomery(s, s, ckinv, group->mont_data, ctx)) {
+ ECerr(EC_F_ECDSA_SIMPLE_SIGN_SIG, ERR_R_BN_LIB);
goto err;
}
+
if (BN_is_zero(s)) {
/*
* if kinv and r have been supplied by the caller, don't
* generate new kinv and r values
*/
if (in_kinv != NULL && in_r != NULL) {
- ECerr(EC_F_OSSL_ECDSA_SIGN_SIG, EC_R_NEED_NEW_SETUP_VALUES);
+ ECerr(EC_F_ECDSA_SIMPLE_SIGN_SIG, EC_R_NEED_NEW_SETUP_VALUES);
goto err;
}
- } else
+ } else {
/* s != 0 => we have a valid signature */
break;
- }
- while (1);
+ }
+ } while (1);
ok = 1;
err:
}
BN_CTX_free(ctx);
BN_clear_free(m);
- BN_clear_free(tmp);
BN_clear_free(kinv);
return ret;
}
return ret;
}
-int ossl_ecdsa_verify_sig(const unsigned char *dgst, int dgst_len,
- const ECDSA_SIG *sig, EC_KEY *eckey)
+int ecdsa_simple_verify_sig(const unsigned char *dgst, int dgst_len,
+ const ECDSA_SIG *sig, EC_KEY *eckey)
{
int ret = -1, i;
BN_CTX *ctx;
/* check input values */
if (eckey == NULL || (group = EC_KEY_get0_group(eckey)) == NULL ||
(pub_key = EC_KEY_get0_public_key(eckey)) == NULL || sig == NULL) {
- ECerr(EC_F_OSSL_ECDSA_VERIFY_SIG, EC_R_MISSING_PARAMETERS);
+ ECerr(EC_F_ECDSA_SIMPLE_VERIFY_SIG, EC_R_MISSING_PARAMETERS);
return -1;
}
if (!EC_KEY_can_sign(eckey)) {
- ECerr(EC_F_OSSL_ECDSA_VERIFY_SIG, EC_R_CURVE_DOES_NOT_SUPPORT_SIGNING);
+ ECerr(EC_F_ECDSA_SIMPLE_VERIFY_SIG, EC_R_CURVE_DOES_NOT_SUPPORT_SIGNING);
return -1;
}
- ctx = BN_CTX_new();
+ ctx = BN_CTX_new_ex(eckey->libctx);
if (ctx == NULL) {
- ECerr(EC_F_OSSL_ECDSA_VERIFY_SIG, ERR_R_MALLOC_FAILURE);
+ ECerr(EC_F_ECDSA_SIMPLE_VERIFY_SIG, ERR_R_MALLOC_FAILURE);
return -1;
}
BN_CTX_start(ctx);
m = BN_CTX_get(ctx);
X = BN_CTX_get(ctx);
if (X == NULL) {
- ECerr(EC_F_OSSL_ECDSA_VERIFY_SIG, ERR_R_BN_LIB);
+ ECerr(EC_F_ECDSA_SIMPLE_VERIFY_SIG, ERR_R_BN_LIB);
goto err;
}
order = EC_GROUP_get0_order(group);
if (order == NULL) {
- ECerr(EC_F_OSSL_ECDSA_VERIFY_SIG, ERR_R_EC_LIB);
+ ECerr(EC_F_ECDSA_SIMPLE_VERIFY_SIG, 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) {
- ECerr(EC_F_OSSL_ECDSA_VERIFY_SIG, EC_R_BAD_SIGNATURE);
+ ECerr(EC_F_ECDSA_SIMPLE_VERIFY_SIG, EC_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)) {
- ECerr(EC_F_OSSL_ECDSA_VERIFY_SIG, ERR_R_BN_LIB);
+ if (!ec_group_do_inverse_ord(group, u2, sig->s, ctx)) {
+ ECerr(EC_F_ECDSA_SIMPLE_VERIFY_SIG, ERR_R_BN_LIB);
goto err;
}
/* digest -> m */
if (8 * dgst_len > i)
dgst_len = (i + 7) / 8;
if (!BN_bin2bn(dgst, dgst_len, m)) {
- ECerr(EC_F_OSSL_ECDSA_VERIFY_SIG, ERR_R_BN_LIB);
+ ECerr(EC_F_ECDSA_SIMPLE_VERIFY_SIG, 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))) {
- ECerr(EC_F_OSSL_ECDSA_VERIFY_SIG, ERR_R_BN_LIB);
+ ECerr(EC_F_ECDSA_SIMPLE_VERIFY_SIG, ERR_R_BN_LIB);
goto err;
}
/* u1 = m * tmp mod order */
if (!BN_mod_mul(u1, m, u2, order, ctx)) {
- ECerr(EC_F_OSSL_ECDSA_VERIFY_SIG, ERR_R_BN_LIB);
+ ECerr(EC_F_ECDSA_SIMPLE_VERIFY_SIG, ERR_R_BN_LIB);
goto err;
}
/* u2 = r * w mod q */
if (!BN_mod_mul(u2, sig->r, u2, order, ctx)) {
- ECerr(EC_F_OSSL_ECDSA_VERIFY_SIG, ERR_R_BN_LIB);
+ ECerr(EC_F_ECDSA_SIMPLE_VERIFY_SIG, ERR_R_BN_LIB);
goto err;
}
if ((point = EC_POINT_new(group)) == NULL) {
- ECerr(EC_F_OSSL_ECDSA_VERIFY_SIG, ERR_R_MALLOC_FAILURE);
+ ECerr(EC_F_ECDSA_SIMPLE_VERIFY_SIG, ERR_R_MALLOC_FAILURE);
goto err;
}
if (!EC_POINT_mul(group, point, u1, pub_key, u2, ctx)) {
- ECerr(EC_F_OSSL_ECDSA_VERIFY_SIG, ERR_R_EC_LIB);
+ ECerr(EC_F_ECDSA_SIMPLE_VERIFY_SIG, 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)) {
- ECerr(EC_F_OSSL_ECDSA_VERIFY_SIG, ERR_R_EC_LIB);
- goto err;
- }
- }
-#ifndef OPENSSL_NO_EC2M
- else { /* NID_X9_62_characteristic_two_field */
- if (!EC_POINT_get_affine_coordinates_GF2m(group, point, X, NULL, ctx)) {
- ECerr(EC_F_OSSL_ECDSA_VERIFY_SIG, ERR_R_EC_LIB);
- goto err;
- }
+ if (!EC_POINT_get_affine_coordinates(group, point, X, NULL, ctx)) {
+ ECerr(EC_F_ECDSA_SIMPLE_VERIFY_SIG, ERR_R_EC_LIB);
+ goto err;
}
-#endif
+
if (!BN_nnmod(u1, X, order, ctx)) {
- ECerr(EC_F_OSSL_ECDSA_VERIFY_SIG, ERR_R_BN_LIB);
+ ECerr(EC_F_ECDSA_SIMPLE_VERIFY_SIG, ERR_R_BN_LIB);
goto err;
}
/* if the signature is correct u1 is equal to sig->r */