/*
- * Copyright 2002-2016 The OpenSSL Project Authors. All Rights Reserved.
+ * Copyright 2002-2020 The OpenSSL Project Authors. All Rights Reserved.
+ * Copyright (c) 2002, Oracle and/or its affiliates. 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
*/
-/* ====================================================================
- * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
- * Portions originally developed by SUN MICROSYSTEMS, INC., and
- * contributed to the OpenSSL project.
+/*
+ * ECDSA low level APIs are deprecated for public use, but still ok for
+ * internal use.
*/
+#include "internal/deprecated.h"
-#include <internal/cryptlib.h>
+#include "internal/cryptlib.h"
#include <string.h>
-#include "ec_lcl.h"
+#include "ec_local.h"
+#include "internal/refcount.h"
#include <openssl/err.h>
#include <openssl/engine.h>
+#include <openssl/self_test.h>
+#include "crypto/bn.h"
+
+static int ecdsa_keygen_pairwise_test(EC_KEY *eckey, OSSL_CALLBACK *cb,
+ void *cbarg);
+#ifndef FIPS_MODE
EC_KEY *EC_KEY_new(void)
{
- return EC_KEY_new_method(NULL);
+ return ec_key_new_method_int(NULL, NULL);
}
+#endif
-EC_KEY *EC_KEY_new_by_curve_name(int nid)
+EC_KEY *EC_KEY_new_ex(OPENSSL_CTX *ctx)
+{
+ return ec_key_new_method_int(ctx, NULL);
+}
+
+EC_KEY *EC_KEY_new_by_curve_name_ex(OPENSSL_CTX *ctx, int nid)
{
- EC_KEY *ret = EC_KEY_new();
+ EC_KEY *ret = EC_KEY_new_ex(ctx);
if (ret == NULL)
return NULL;
- ret->group = EC_GROUP_new_by_curve_name(nid);
+ ret->group = EC_GROUP_new_by_curve_name_ex(ctx, nid);
if (ret->group == NULL) {
EC_KEY_free(ret);
return NULL;
return ret;
}
+#ifndef FIPS_MODE
+EC_KEY *EC_KEY_new_by_curve_name(int nid)
+{
+ return EC_KEY_new_by_curve_name_ex(NULL, nid);
+}
+#endif
+
void EC_KEY_free(EC_KEY *r)
{
int i;
if (r == NULL)
return;
- CRYPTO_atomic_add(&r->references, -1, &i, r->lock);
+ CRYPTO_DOWN_REF(&r->references, &i, r->lock);
REF_PRINT_COUNT("EC_KEY", r);
if (i > 0)
return;
REF_ASSERT_ISNT(i < 0);
- if (r->meth->finish != NULL)
+ if (r->meth != NULL && r->meth->finish != NULL)
r->meth->finish(r);
-#ifndef OPENSSL_NO_ENGINE
+#if !defined(OPENSSL_NO_ENGINE) && !defined(FIPS_MODE)
ENGINE_finish(r->engine);
#endif
if (r->group && r->group->meth->keyfinish)
r->group->meth->keyfinish(r);
+#ifndef FIPS_MODE
CRYPTO_free_ex_data(CRYPTO_EX_INDEX_EC_KEY, r, &r->ex_data);
+#endif
CRYPTO_THREAD_lock_free(r->lock);
EC_GROUP_free(r->group);
EC_POINT_free(r->pub_key);
OPENSSL_clear_free((void *)r, sizeof(EC_KEY));
}
-EC_KEY *EC_KEY_copy(EC_KEY *dest, EC_KEY *src)
+EC_KEY *EC_KEY_copy(EC_KEY *dest, const EC_KEY *src)
{
if (dest == NULL || src == NULL) {
ECerr(EC_F_EC_KEY_COPY, ERR_R_PASSED_NULL_PARAMETER);
dest->meth->finish(dest);
if (dest->group && dest->group->meth->keyfinish)
dest->group->meth->keyfinish(dest);
-#ifndef OPENSSL_NO_ENGINE
+#if !defined(OPENSSL_NO_ENGINE) && !defined(FIPS_MODE)
if (ENGINE_finish(dest->engine) == 0)
return 0;
dest->engine = NULL;
#endif
}
+ dest->libctx = src->libctx;
/* copy the parameters */
if (src->group != NULL) {
const EC_METHOD *meth = EC_GROUP_method_of(src->group);
/* clear the old group */
EC_GROUP_free(dest->group);
- dest->group = EC_GROUP_new(meth);
+ dest->group = EC_GROUP_new_ex(src->libctx, meth);
if (dest->group == NULL)
return NULL;
if (!EC_GROUP_copy(dest->group, src->group))
dest->conv_form = src->conv_form;
dest->version = src->version;
dest->flags = src->flags;
+#ifndef FIPS_MODE
if (!CRYPTO_dup_ex_data(CRYPTO_EX_INDEX_EC_KEY,
&dest->ex_data, &src->ex_data))
return NULL;
+#endif
if (src->meth != dest->meth) {
-#ifndef OPENSSL_NO_ENGINE
+#if !defined(OPENSSL_NO_ENGINE) && !defined(FIPS_MODE)
if (src->engine != NULL && ENGINE_init(src->engine) == 0)
return NULL;
dest->engine = src->engine;
if (src->meth->copy != NULL && src->meth->copy(dest, src) == 0)
return NULL;
+ dest->dirty_cnt++;
+
return dest;
}
-EC_KEY *EC_KEY_dup(EC_KEY *ec_key)
+EC_KEY *EC_KEY_dup(const EC_KEY *ec_key)
{
- EC_KEY *ret = EC_KEY_new_method(ec_key->engine);
+ EC_KEY *ret = ec_key_new_method_int(ec_key->libctx, ec_key->engine);
if (ret == NULL)
return NULL;
{
int i;
- if (CRYPTO_atomic_add(&r->references, 1, &i, r->lock) <= 0)
+ if (CRYPTO_UP_REF(&r->references, &i, r->lock) <= 0)
return 0;
REF_PRINT_COUNT("EC_KEY", r);
return ((i > 1) ? 1 : 0);
}
+ENGINE *EC_KEY_get0_engine(const EC_KEY *eckey)
+{
+ return eckey->engine;
+}
+
int EC_KEY_generate_key(EC_KEY *eckey)
{
if (eckey == NULL || eckey->group == NULL) {
ECerr(EC_F_EC_KEY_GENERATE_KEY, ERR_R_PASSED_NULL_PARAMETER);
return 0;
}
- if (eckey->meth->keygen != NULL)
- return eckey->meth->keygen(eckey);
+ if (eckey->meth->keygen != NULL) {
+ int ret;
+
+ ret = eckey->meth->keygen(eckey);
+ if (ret == 1)
+ eckey->dirty_cnt++;
+
+ return ret;
+ }
ECerr(EC_F_EC_KEY_GENERATE_KEY, EC_R_OPERATION_NOT_SUPPORTED);
return 0;
}
int ossl_ec_key_gen(EC_KEY *eckey)
{
- OPENSSL_assert(eckey->group->meth->keygen != NULL);
- return eckey->group->meth->keygen(eckey);
+ int ret;
+
+ ret = eckey->group->meth->keygen(eckey);
+
+ if (ret == 1)
+ eckey->dirty_cnt++;
+ return ret;
}
-int ec_key_simple_generate_key(EC_KEY *eckey)
+/*
+ * ECC Key generation.
+ * See SP800-56AR3 5.6.1.2.2 "Key Pair Generation by Testing Candidates"
+ *
+ * Params:
+ * libctx A context containing an optional self test callback.
+ * eckey An EC key object that contains domain params. The generated keypair
+ * is stored in this object.
+ * pairwise_test Set to non zero to perform a pairwise test. If the test
+ * fails then the keypair is not generated,
+ * Returns 1 if the keypair was generated or 0 otherwise.
+ */
+int ec_generate_key(OPENSSL_CTX *libctx, EC_KEY *eckey, int pairwise_test)
{
int ok = 0;
- BN_CTX *ctx = NULL;
BIGNUM *priv_key = NULL;
const BIGNUM *order = NULL;
EC_POINT *pub_key = NULL;
+ const EC_GROUP *group = eckey->group;
+ BN_CTX *ctx = BN_CTX_secure_new_ex(eckey->libctx);
- if ((ctx = BN_CTX_new()) == NULL)
+ if (ctx == NULL)
goto err;
if (eckey->priv_key == NULL) {
- priv_key = BN_new();
+ priv_key = BN_secure_new();
if (priv_key == NULL)
goto err;
} else
priv_key = eckey->priv_key;
- order = EC_GROUP_get0_order(eckey->group);
+ /*
+ * Steps (1-2): Check domain parameters and security strength.
+ * These steps must be done by the user. This would need to be
+ * stated in the security policy.
+ */
+
+ order = EC_GROUP_get0_order(group);
if (order == NULL)
goto err;
+ /*
+ * Steps (3-7): priv_key = DRBG_RAND(order_n_bits) (range [1, n-1]).
+ * Although this is slightly different from the standard, it is effectively
+ * equivalent as it gives an unbiased result ranging from 1..n-1. It is also
+ * faster as the standard needs to retry more often. Also doing
+ * 1 + rand[0..n-2] would effect the way that tests feed dummy entropy into
+ * rand so the simpler backward compatible method has been used here.
+ */
do
- if (!BN_rand_range(priv_key, order))
+ if (!BN_priv_rand_range_ex(priv_key, order, ctx))
goto err;
while (BN_is_zero(priv_key)) ;
if (eckey->pub_key == NULL) {
- pub_key = EC_POINT_new(eckey->group);
+ pub_key = EC_POINT_new(group);
if (pub_key == NULL)
goto err;
} else
pub_key = eckey->pub_key;
- if (!EC_POINT_mul(eckey->group, pub_key, priv_key, NULL, NULL, ctx))
+ /* Step (8) : pub_key = priv_key * G (where G is a point on the curve) */
+ if (!EC_POINT_mul(group, pub_key, priv_key, NULL, NULL, ctx))
goto err;
eckey->priv_key = priv_key;
eckey->pub_key = pub_key;
+ priv_key = NULL;
+ pub_key = NULL;
+
+ eckey->dirty_cnt++;
+
+#ifdef FIPS_MODE
+ pairwise_test = 1;
+#endif /* FIPS_MODE */
ok = 1;
+ if (pairwise_test) {
+ OSSL_CALLBACK *cb = NULL;
+ void *cbarg = NULL;
- err:
- if (eckey->pub_key == NULL)
- EC_POINT_free(pub_key);
- if (eckey->priv_key != priv_key)
- BN_free(priv_key);
+ OSSL_SELF_TEST_get_callback(libctx, &cb, &cbarg);
+ ok = ecdsa_keygen_pairwise_test(eckey, cb, cbarg);
+ }
+err:
+ /* Step (9): If there is an error return an invalid keypair. */
+ if (!ok) {
+ BN_clear(eckey->priv_key);
+ if (eckey->pub_key != NULL)
+ EC_POINT_set_to_infinity(group, eckey->pub_key);
+ }
+
+ EC_POINT_free(pub_key);
+ BN_clear_free(priv_key);
BN_CTX_free(ctx);
return ok;
}
+int ec_key_simple_generate_key(EC_KEY *eckey)
+{
+ return ec_generate_key(NULL, eckey, 0);
+}
+
int ec_key_simple_generate_public_key(EC_KEY *eckey)
{
- return EC_POINT_mul(eckey->group, eckey->pub_key, eckey->priv_key, NULL,
- NULL, NULL);
+ int ret;
+
+ /*
+ * See SP800-56AR3 5.6.1.2.2: Step (8)
+ * pub_key = priv_key * G (where G is a point on the curve)
+ */
+ ret = EC_POINT_mul(eckey->group, eckey->pub_key, eckey->priv_key, NULL,
+ NULL, NULL);
+
+ if (ret == 1)
+ eckey->dirty_cnt++;
+
+ return ret;
}
int EC_KEY_check_key(const EC_KEY *eckey)
return eckey->group->meth->keycheck(eckey);
}
-int ec_key_simple_check_key(const EC_KEY *eckey)
+/*
+ * Check the range of the EC public key.
+ * See SP800-56A R3 Section 5.6.2.3.3 (Part 2)
+ * i.e.
+ * - If q = odd prime p: Verify that xQ and yQ are integers in the
+ * interval[0, p - 1], OR
+ * - If q = 2m: Verify that xQ and yQ are bit strings of length m bits.
+ * Returns 1 if the public key has a valid range, otherwise it returns 0.
+ */
+static int ec_key_public_range_check(BN_CTX *ctx, const EC_KEY *key)
{
- int ok = 0;
- BN_CTX *ctx = NULL;
- const BIGNUM *order = NULL;
+ int ret = 0;
+ BIGNUM *x, *y;
+
+ BN_CTX_start(ctx);
+ x = BN_CTX_get(ctx);
+ y = BN_CTX_get(ctx);
+ if (y == NULL)
+ goto err;
+
+ if (!EC_POINT_get_affine_coordinates(key->group, key->pub_key, x, y, ctx))
+ goto err;
+
+ if (EC_METHOD_get_field_type(key->group->meth) == NID_X9_62_prime_field) {
+ if (BN_is_negative(x)
+ || BN_cmp(x, key->group->field) >= 0
+ || BN_is_negative(y)
+ || BN_cmp(y, key->group->field) >= 0) {
+ goto err;
+ }
+ } else {
+ int m = EC_GROUP_get_degree(key->group);
+ if (BN_num_bits(x) > m || BN_num_bits(y) > m) {
+ goto err;
+ }
+ }
+ ret = 1;
+err:
+ BN_CTX_end(ctx);
+ return ret;
+}
+
+/*
+ * ECC Key validation as specified in SP800-56A R3.
+ * Section 5.6.2.3.3 ECC Full Public-Key Validation.
+ */
+int ec_key_public_check(const EC_KEY *eckey, BN_CTX *ctx)
+{
+ int ret = 0;
EC_POINT *point = NULL;
+ const BIGNUM *order = NULL;
if (eckey == NULL || eckey->group == NULL || eckey->pub_key == NULL) {
- ECerr(EC_F_EC_KEY_SIMPLE_CHECK_KEY, ERR_R_PASSED_NULL_PARAMETER);
+ ECerr(0, ERR_R_PASSED_NULL_PARAMETER);
return 0;
}
+ /* 5.6.2.3.3 (Step 1): Q != infinity */
if (EC_POINT_is_at_infinity(eckey->group, eckey->pub_key)) {
- ECerr(EC_F_EC_KEY_SIMPLE_CHECK_KEY, EC_R_POINT_AT_INFINITY);
- goto err;
+ ECerr(0, EC_R_POINT_AT_INFINITY);
+ return 0;
}
- if ((ctx = BN_CTX_new()) == NULL)
- goto err;
- if ((point = EC_POINT_new(eckey->group)) == NULL)
+ point = EC_POINT_new(eckey->group);
+ if (point == NULL)
+ return 0;
+
+ /* 5.6.2.3.3 (Step 2) Test if the public key is in range */
+ if (!ec_key_public_range_check(ctx, eckey)) {
+ ECerr(0, EC_R_COORDINATES_OUT_OF_RANGE);
goto err;
+ }
- /* testing whether the pub_key is on the elliptic curve */
+ /* 5.6.2.3.3 (Step 3) is the pub_key on the elliptic curve */
if (EC_POINT_is_on_curve(eckey->group, eckey->pub_key, ctx) <= 0) {
- ECerr(EC_F_EC_KEY_SIMPLE_CHECK_KEY, EC_R_POINT_IS_NOT_ON_CURVE);
+ ECerr(0, EC_R_POINT_IS_NOT_ON_CURVE);
goto err;
}
- /* testing whether pub_key * order is the point at infinity */
+
order = eckey->group->order;
if (BN_is_zero(order)) {
- ECerr(EC_F_EC_KEY_SIMPLE_CHECK_KEY, EC_R_INVALID_GROUP_ORDER);
+ ECerr(0, EC_R_INVALID_GROUP_ORDER);
goto err;
}
+ /* 5.6.2.3.3 (Step 4) : pub_key * order is the point at infinity. */
if (!EC_POINT_mul(eckey->group, point, NULL, eckey->pub_key, order, ctx)) {
- ECerr(EC_F_EC_KEY_SIMPLE_CHECK_KEY, ERR_R_EC_LIB);
+ ECerr(0, ERR_R_EC_LIB);
goto err;
}
if (!EC_POINT_is_at_infinity(eckey->group, point)) {
- ECerr(EC_F_EC_KEY_SIMPLE_CHECK_KEY, EC_R_WRONG_ORDER);
+ ECerr(0, EC_R_WRONG_ORDER);
goto err;
}
- /*
- * in case the priv_key is present : check if generator * priv_key ==
- * pub_key
- */
+ ret = 1;
+err:
+ EC_POINT_free(point);
+ return ret;
+}
+
+/*
+ * ECC Key validation as specified in SP800-56A R3.
+ * Section 5.6.2.1.2 Owner Assurance of Private-Key Validity
+ * The private key is in the range [1, order-1]
+ */
+int ec_key_private_check(const EC_KEY *eckey)
+{
+ if (eckey == NULL || eckey->group == NULL || eckey->priv_key == NULL) {
+ ECerr(0, ERR_R_PASSED_NULL_PARAMETER);
+ return 0;
+ }
+ if (BN_cmp(eckey->priv_key, BN_value_one()) < 0
+ || BN_cmp(eckey->priv_key, eckey->group->order) >= 0) {
+ ECerr(0, EC_R_INVALID_PRIVATE_KEY);
+ return 0;
+ }
+ return 1;
+}
+
+/*
+ * ECC Key validation as specified in SP800-56A R3.
+ * Section 5.6.2.1.4 Owner Assurance of Pair-wise Consistency (b)
+ * Check if generator * priv_key = pub_key
+ */
+int ec_key_pairwise_check(const EC_KEY *eckey, BN_CTX *ctx)
+{
+ int ret = 0;
+ EC_POINT *point = NULL;
+
+ if (eckey == NULL
+ || eckey->group == NULL
+ || eckey->pub_key == NULL
+ || eckey->priv_key == NULL) {
+ ECerr(0, ERR_R_PASSED_NULL_PARAMETER);
+ return 0;
+ }
+
+ point = EC_POINT_new(eckey->group);
+ if (point == NULL)
+ goto err;
+
+
+ if (!EC_POINT_mul(eckey->group, point, eckey->priv_key, NULL, NULL, ctx)) {
+ ECerr(0, ERR_R_EC_LIB);
+ goto err;
+ }
+ if (EC_POINT_cmp(eckey->group, point, eckey->pub_key, ctx) != 0) {
+ ECerr(0, EC_R_INVALID_PRIVATE_KEY);
+ goto err;
+ }
+ ret = 1;
+err:
+ EC_POINT_free(point);
+ return ret;
+}
+
+
+/*
+ * ECC Key validation as specified in SP800-56A R3.
+ * Section 5.6.2.3.3 ECC Full Public-Key Validation
+ * Section 5.6.2.1.2 Owner Assurance of Private-Key Validity
+ * Section 5.6.2.1.4 Owner Assurance of Pair-wise Consistency
+ * NOTES:
+ * Before calling this method in fips mode, there should be an assurance that
+ * an approved elliptic-curve group is used.
+ * Returns 1 if the key is valid, otherwise it returns 0.
+ */
+int ec_key_simple_check_key(const EC_KEY *eckey)
+{
+ int ok = 0;
+ BN_CTX *ctx = NULL;
+
+ if (eckey == NULL) {
+ ECerr(0, ERR_R_PASSED_NULL_PARAMETER);
+ return 0;
+ }
+ if ((ctx = BN_CTX_new_ex(eckey->libctx)) == NULL)
+ return 0;
+
+ if (!ec_key_public_check(eckey, ctx))
+ goto err;
+
if (eckey->priv_key != NULL) {
- if (BN_cmp(eckey->priv_key, order) >= 0) {
- ECerr(EC_F_EC_KEY_SIMPLE_CHECK_KEY, EC_R_WRONG_ORDER);
- goto err;
- }
- if (!EC_POINT_mul(eckey->group, point, eckey->priv_key,
- NULL, NULL, ctx)) {
- ECerr(EC_F_EC_KEY_SIMPLE_CHECK_KEY, ERR_R_EC_LIB);
+ if (!ec_key_private_check(eckey)
+ || !ec_key_pairwise_check(eckey, ctx))
goto err;
- }
- if (EC_POINT_cmp(eckey->group, point, eckey->pub_key, ctx) != 0) {
- ECerr(EC_F_EC_KEY_SIMPLE_CHECK_KEY, EC_R_INVALID_PRIVATE_KEY);
- goto err;
- }
}
ok = 1;
- err:
+err:
BN_CTX_free(ctx);
- EC_POINT_free(point);
return ok;
}
BIGNUM *tx, *ty;
EC_POINT *point = NULL;
int ok = 0;
-#ifndef OPENSSL_NO_EC2M
- int tmp_nid, is_char_two = 0;
-#endif
if (key == NULL || key->group == NULL || x == NULL || y == NULL) {
ECerr(EC_F_EC_KEY_SET_PUBLIC_KEY_AFFINE_COORDINATES,
ERR_R_PASSED_NULL_PARAMETER);
return 0;
}
- ctx = BN_CTX_new();
+ ctx = BN_CTX_new_ex(key->libctx);
if (ctx == NULL)
return 0;
if (ty == NULL)
goto err;
-#ifndef OPENSSL_NO_EC2M
- tmp_nid = EC_METHOD_get_field_type(EC_GROUP_method_of(key->group));
-
- if (tmp_nid == NID_X9_62_characteristic_two_field)
- is_char_two = 1;
+ if (!EC_POINT_set_affine_coordinates(key->group, point, x, y, ctx))
+ goto err;
+ if (!EC_POINT_get_affine_coordinates(key->group, point, tx, ty, ctx))
+ goto err;
- if (is_char_two) {
- if (!EC_POINT_set_affine_coordinates_GF2m(key->group, point,
- x, y, ctx))
- goto err;
- if (!EC_POINT_get_affine_coordinates_GF2m(key->group, point,
- tx, ty, ctx))
- goto err;
- } else
-#endif
- {
- if (!EC_POINT_set_affine_coordinates_GFp(key->group, point,
- x, y, ctx))
- goto err;
- if (!EC_POINT_get_affine_coordinates_GFp(key->group, point,
- tx, ty, ctx))
- goto err;
- }
/*
- * Check if retrieved coordinates match originals and are less than field
- * order: if not values are out of range.
+ * Check if retrieved coordinates match originals. The range check is done
+ * inside EC_KEY_check_key().
*/
- if (BN_cmp(x, tx) || BN_cmp(y, ty)
- || (BN_cmp(x, key->group->field) >= 0)
- || (BN_cmp(y, key->group->field) >= 0)) {
+ if (BN_cmp(x, tx) || BN_cmp(y, ty)) {
ECerr(EC_F_EC_KEY_SET_PUBLIC_KEY_AFFINE_COORDINATES,
EC_R_COORDINATES_OUT_OF_RANGE);
goto err;
}
+ /* EC_KEY_set_public_key updates dirty_cnt */
if (!EC_KEY_set_public_key(key, point))
goto err;
}
+OPENSSL_CTX *ec_key_get_libctx(const EC_KEY *key)
+{
+ return key->libctx;
+}
+
const EC_GROUP *EC_KEY_get0_group(const EC_KEY *key)
{
return key->group;
return 0;
EC_GROUP_free(key->group);
key->group = EC_GROUP_dup(group);
+ key->dirty_cnt++;
return (key->group == NULL) ? 0 : 1;
}
int EC_KEY_set_private_key(EC_KEY *key, const BIGNUM *priv_key)
{
+ int fixed_top;
+ const BIGNUM *order = NULL;
+ BIGNUM *tmp_key = NULL;
+
if (key->group == NULL || key->group->meth == NULL)
return 0;
+
+ /*
+ * Not only should key->group be set, but it should also be in a valid
+ * fully initialized state.
+ *
+ * Specifically, to operate in constant time, we need that the group order
+ * is set, as we use its length as the fixed public size of any scalar used
+ * as an EC private key.
+ */
+ order = EC_GROUP_get0_order(key->group);
+ if (order == NULL || BN_is_zero(order))
+ return 0; /* This should never happen */
+
if (key->group->meth->set_private != NULL
&& key->group->meth->set_private(key, priv_key) == 0)
return 0;
if (key->meth->set_private != NULL
&& key->meth->set_private(key, priv_key) == 0)
return 0;
+
+ /*
+ * We should never leak the bit length of the secret scalar in the key,
+ * so we always set the `BN_FLG_CONSTTIME` flag on the internal `BIGNUM`
+ * holding the secret scalar.
+ *
+ * This is important also because `BN_dup()` (and `BN_copy()`) do not
+ * propagate the `BN_FLG_CONSTTIME` flag from the source `BIGNUM`, and
+ * this brings an extra risk of inadvertently losing the flag, even when
+ * the caller specifically set it.
+ *
+ * The propagation has been turned on and off a few times in the past
+ * years because in some conditions has shown unintended consequences in
+ * some code paths, so at the moment we can't fix this in the BN layer.
+ *
+ * In `EC_KEY_set_private_key()` we can work around the propagation by
+ * manually setting the flag after `BN_dup()` as we know for sure that
+ * inside the EC module the `BN_FLG_CONSTTIME` is always treated
+ * correctly and should not generate unintended consequences.
+ *
+ * Setting the BN_FLG_CONSTTIME flag alone is never enough, we also have
+ * to preallocate the BIGNUM internal buffer to a fixed public size big
+ * enough that operations performed during the processing never trigger
+ * a realloc which would leak the size of the scalar through memory
+ * accesses.
+ *
+ * Fixed Length
+ * ------------
+ *
+ * The order of the large prime subgroup of the curve is our choice for
+ * a fixed public size, as that is generally the upper bound for
+ * generating a private key in EC cryptosystems and should fit all valid
+ * secret scalars.
+ *
+ * For preallocating the BIGNUM storage we look at the number of "words"
+ * required for the internal representation of the order, and we
+ * preallocate 2 extra "words" in case any of the subsequent processing
+ * might temporarily overflow the order length.
+ */
+ tmp_key = BN_dup(priv_key);
+ if (tmp_key == NULL)
+ return 0;
+
+ BN_set_flags(tmp_key, BN_FLG_CONSTTIME);
+
+ fixed_top = bn_get_top(order) + 2;
+ if (bn_wexpand(tmp_key, fixed_top) == NULL) {
+ BN_clear_free(tmp_key);
+ return 0;
+ }
+
BN_clear_free(key->priv_key);
- key->priv_key = BN_dup(priv_key);
- return (key->priv_key == NULL) ? 0 : 1;
+ key->priv_key = tmp_key;
+ key->dirty_cnt++;
+
+ return 1;
}
const EC_POINT *EC_KEY_get0_public_key(const EC_KEY *key)
return 0;
EC_POINT_free(key->pub_key);
key->pub_key = EC_POINT_dup(pub_key, key->group);
+ key->dirty_cnt++;
return (key->pub_key == NULL) ? 0 : 1;
}
void EC_KEY_set_flags(EC_KEY *key, int flags)
{
key->flags |= flags;
+ key->dirty_cnt++;
}
void EC_KEY_clear_flags(EC_KEY *key, int flags)
{
key->flags &= ~flags;
+ key->dirty_cnt++;
}
size_t EC_KEY_key2buf(const EC_KEY *key, point_conversion_form_t form,
return 0;
if (EC_POINT_oct2point(key->group, key->pub_key, buf, len, ctx) == 0)
return 0;
+ key->dirty_cnt++;
/*
* Save the point conversion form.
* For non-custom curves the first octet of the buffer (excluding
return 1;
}
-size_t EC_KEY_priv2oct(const EC_KEY *eckey,
+size_t EC_KEY_priv2oct(const EC_KEY *eckey,
unsigned char *buf, size_t len)
{
if (eckey->group == NULL || eckey->group->meth == NULL)
int EC_KEY_oct2priv(EC_KEY *eckey, const unsigned char *buf, size_t len)
{
+ int ret;
+
if (eckey->group == NULL || eckey->group->meth == NULL)
return 0;
if (eckey->group->meth->oct2priv == NULL) {
ECerr(EC_F_EC_KEY_OCT2PRIV, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
return 0;
}
- return eckey->group->meth->oct2priv(eckey, buf, len);
+ ret = eckey->group->meth->oct2priv(eckey, buf, len);
+ if (ret == 1)
+ eckey->dirty_cnt++;
+ return ret;
}
int ec_key_simple_oct2priv(EC_KEY *eckey, const unsigned char *buf, size_t len)
ECerr(EC_F_EC_KEY_SIMPLE_OCT2PRIV, ERR_R_BN_LIB);
return 0;
}
+ eckey->dirty_cnt++;
return 1;
}
{
size_t len;
unsigned char *buf;
+
len = EC_KEY_priv2oct(eckey, NULL, 0);
if (len == 0)
return 0;
- buf = OPENSSL_malloc(len);
- if (buf == NULL)
+ if ((buf = OPENSSL_malloc(len)) == NULL) {
+ ECerr(EC_F_EC_KEY_PRIV2BUF, ERR_R_MALLOC_FAILURE);
return 0;
+ }
len = EC_KEY_priv2oct(eckey, buf, len);
if (len == 0) {
OPENSSL_free(buf);
return 0;
return 1;
}
+
+/*
+ * FIPS 140-2 IG 9.9 AS09.33
+ * Perform a sign/verify operation.
+ *
+ * NOTE: When generating keys for key-agreement schemes - FIPS 140-2 IG 9.9
+ * states that no additional pairwise tests are required (apart from the tests
+ * specified in SP800-56A) when generating keys. Hence pairwise ECDH tests are
+ * omitted here.
+ */
+static int ecdsa_keygen_pairwise_test(EC_KEY *eckey, OSSL_CALLBACK *cb,
+ void *cbarg)
+{
+ int ret = 0;
+ unsigned char dgst[16] = {0};
+ int dgst_len = (int)sizeof(dgst);
+ ECDSA_SIG *sig = NULL;
+ OSSL_SELF_TEST *st = NULL;
+
+ st = OSSL_SELF_TEST_new(cb, cbarg);
+ if (st == NULL)
+ return 0;
+
+ OSSL_SELF_TEST_onbegin(st, OSSL_SELF_TEST_TYPE_PCT,
+ OSSL_SELF_TEST_DESC_PCT_ECDSA);
+
+ sig = ECDSA_do_sign(dgst, dgst_len, eckey);
+ if (sig == NULL)
+ goto err;
+
+ OSSL_SELF_TEST_oncorrupt_byte(st, dgst);
+
+ if (ECDSA_do_verify(dgst, dgst_len, sig, eckey) != 1)
+ goto err;
+
+ ret = 1;
+err:
+ OSSL_SELF_TEST_onend(st, ret);
+ OSSL_SELF_TEST_free(st);
+ ECDSA_SIG_free(sig);
+ return ret;
+}
projects / openssl.git / blobdiff