/*
- * Copyright 2001-2018 The OpenSSL Project Authors. All Rights Reserved.
+ * Copyright 2001-2022 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
*/
+/*
+ * ECDSA low-level APIs are deprecated for public use, but still ok for
+ * internal use.
+ */
+#include "internal/deprecated.h"
+
#include <openssl/err.h>
#include <openssl/symhacks.h>
-#include "ec_lcl.h"
+#include "ec_local.h"
const EC_METHOD *EC_GFp_simple_method(void)
{
static const EC_METHOD ret = {
EC_FLAGS_DEFAULT_OCT,
NID_X9_62_prime_field,
- ec_GFp_simple_group_init,
- ec_GFp_simple_group_finish,
- ec_GFp_simple_group_clear_finish,
- ec_GFp_simple_group_copy,
- ec_GFp_simple_group_set_curve,
- ec_GFp_simple_group_get_curve,
- ec_GFp_simple_group_get_degree,
- ec_group_simple_order_bits,
- ec_GFp_simple_group_check_discriminant,
- ec_GFp_simple_point_init,
- ec_GFp_simple_point_finish,
- ec_GFp_simple_point_clear_finish,
- ec_GFp_simple_point_copy,
- ec_GFp_simple_point_set_to_infinity,
- ec_GFp_simple_set_Jprojective_coordinates_GFp,
- ec_GFp_simple_get_Jprojective_coordinates_GFp,
- ec_GFp_simple_point_set_affine_coordinates,
- ec_GFp_simple_point_get_affine_coordinates,
+ ossl_ec_GFp_simple_group_init,
+ ossl_ec_GFp_simple_group_finish,
+ ossl_ec_GFp_simple_group_clear_finish,
+ ossl_ec_GFp_simple_group_copy,
+ ossl_ec_GFp_simple_group_set_curve,
+ ossl_ec_GFp_simple_group_get_curve,
+ ossl_ec_GFp_simple_group_get_degree,
+ ossl_ec_group_simple_order_bits,
+ ossl_ec_GFp_simple_group_check_discriminant,
+ ossl_ec_GFp_simple_point_init,
+ ossl_ec_GFp_simple_point_finish,
+ ossl_ec_GFp_simple_point_clear_finish,
+ ossl_ec_GFp_simple_point_copy,
+ ossl_ec_GFp_simple_point_set_to_infinity,
+ ossl_ec_GFp_simple_point_set_affine_coordinates,
+ ossl_ec_GFp_simple_point_get_affine_coordinates,
0, 0, 0,
- ec_GFp_simple_add,
- ec_GFp_simple_dbl,
- ec_GFp_simple_invert,
- ec_GFp_simple_is_at_infinity,
- ec_GFp_simple_is_on_curve,
- ec_GFp_simple_cmp,
- ec_GFp_simple_make_affine,
- ec_GFp_simple_points_make_affine,
+ ossl_ec_GFp_simple_add,
+ ossl_ec_GFp_simple_dbl,
+ ossl_ec_GFp_simple_invert,
+ ossl_ec_GFp_simple_is_at_infinity,
+ ossl_ec_GFp_simple_is_on_curve,
+ ossl_ec_GFp_simple_cmp,
+ ossl_ec_GFp_simple_make_affine,
+ ossl_ec_GFp_simple_points_make_affine,
0 /* mul */ ,
0 /* precompute_mult */ ,
0 /* have_precompute_mult */ ,
- ec_GFp_simple_field_mul,
- ec_GFp_simple_field_sqr,
+ ossl_ec_GFp_simple_field_mul,
+ ossl_ec_GFp_simple_field_sqr,
0 /* field_div */ ,
+ ossl_ec_GFp_simple_field_inv,
0 /* field_encode */ ,
0 /* field_decode */ ,
0, /* field_set_to_one */
- ec_key_simple_priv2oct,
- ec_key_simple_oct2priv,
+ ossl_ec_key_simple_priv2oct,
+ ossl_ec_key_simple_oct2priv,
0, /* set private */
- ec_key_simple_generate_key,
- ec_key_simple_check_key,
- ec_key_simple_generate_public_key,
+ ossl_ec_key_simple_generate_key,
+ ossl_ec_key_simple_check_key,
+ ossl_ec_key_simple_generate_public_key,
0, /* keycopy */
0, /* keyfinish */
- ecdh_simple_compute_key,
+ ossl_ecdh_simple_compute_key,
+ ossl_ecdsa_simple_sign_setup,
+ ossl_ecdsa_simple_sign_sig,
+ ossl_ecdsa_simple_verify_sig,
0, /* field_inverse_mod_ord */
- ec_GFp_simple_blind_coordinates,
- 0, /* ladder_pre */
- 0, /* ladder_step */
- 0 /* ladder_post */
+ ossl_ec_GFp_simple_blind_coordinates,
+ ossl_ec_GFp_simple_ladder_pre,
+ ossl_ec_GFp_simple_ladder_step,
+ ossl_ec_GFp_simple_ladder_post
};
return &ret;
* representation (i.e. 'encoding' means multiplying by some factor R).
*/
-int ec_GFp_simple_group_init(EC_GROUP *group)
+int ossl_ec_GFp_simple_group_init(EC_GROUP *group)
{
group->field = BN_new();
group->a = BN_new();
return 1;
}
-void ec_GFp_simple_group_finish(EC_GROUP *group)
+void ossl_ec_GFp_simple_group_finish(EC_GROUP *group)
{
BN_free(group->field);
BN_free(group->a);
BN_free(group->b);
}
-void ec_GFp_simple_group_clear_finish(EC_GROUP *group)
+void ossl_ec_GFp_simple_group_clear_finish(EC_GROUP *group)
{
BN_clear_free(group->field);
BN_clear_free(group->a);
BN_clear_free(group->b);
}
-int ec_GFp_simple_group_copy(EC_GROUP *dest, const EC_GROUP *src)
+int ossl_ec_GFp_simple_group_copy(EC_GROUP *dest, const EC_GROUP *src)
{
if (!BN_copy(dest->field, src->field))
return 0;
return 1;
}
-int ec_GFp_simple_group_set_curve(EC_GROUP *group,
- const BIGNUM *p, const BIGNUM *a,
- const BIGNUM *b, BN_CTX *ctx)
+int ossl_ec_GFp_simple_group_set_curve(EC_GROUP *group,
+ const BIGNUM *p, const BIGNUM *a,
+ const BIGNUM *b, BN_CTX *ctx)
{
int ret = 0;
BN_CTX *new_ctx = NULL;
/* p must be a prime > 3 */
if (BN_num_bits(p) <= 2 || !BN_is_odd(p)) {
- ECerr(EC_F_EC_GFP_SIMPLE_GROUP_SET_CURVE, EC_R_INVALID_FIELD);
+ ERR_raise(ERR_LIB_EC, EC_R_INVALID_FIELD);
return 0;
}
if (ctx == NULL) {
- ctx = new_ctx = BN_CTX_new();
+ ctx = new_ctx = BN_CTX_new_ex(group->libctx);
if (ctx == NULL)
return 0;
}
/* group->a */
if (!BN_nnmod(tmp_a, a, p, ctx))
goto err;
- if (group->meth->field_encode) {
+ if (group->meth->field_encode != NULL) {
if (!group->meth->field_encode(group, group->a, tmp_a, ctx))
goto err;
} else if (!BN_copy(group->a, tmp_a))
/* group->b */
if (!BN_nnmod(group->b, b, p, ctx))
goto err;
- if (group->meth->field_encode)
+ if (group->meth->field_encode != NULL)
if (!group->meth->field_encode(group, group->b, group->b, ctx))
goto err;
return ret;
}
-int ec_GFp_simple_group_get_curve(const EC_GROUP *group, BIGNUM *p, BIGNUM *a,
- BIGNUM *b, BN_CTX *ctx)
+int ossl_ec_GFp_simple_group_get_curve(const EC_GROUP *group, BIGNUM *p,
+ BIGNUM *a, BIGNUM *b, BN_CTX *ctx)
{
int ret = 0;
BN_CTX *new_ctx = NULL;
}
if (a != NULL || b != NULL) {
- if (group->meth->field_decode) {
+ if (group->meth->field_decode != NULL) {
if (ctx == NULL) {
- ctx = new_ctx = BN_CTX_new();
+ ctx = new_ctx = BN_CTX_new_ex(group->libctx);
if (ctx == NULL)
return 0;
}
return ret;
}
-int ec_GFp_simple_group_get_degree(const EC_GROUP *group)
+int ossl_ec_GFp_simple_group_get_degree(const EC_GROUP *group)
{
return BN_num_bits(group->field);
}
-int ec_GFp_simple_group_check_discriminant(const EC_GROUP *group, BN_CTX *ctx)
+int ossl_ec_GFp_simple_group_check_discriminant(const EC_GROUP *group,
+ BN_CTX *ctx)
{
int ret = 0;
BIGNUM *a, *b, *order, *tmp_1, *tmp_2;
BN_CTX *new_ctx = NULL;
if (ctx == NULL) {
- ctx = new_ctx = BN_CTX_new();
+ ctx = new_ctx = BN_CTX_new_ex(group->libctx);
if (ctx == NULL) {
- ECerr(EC_F_EC_GFP_SIMPLE_GROUP_CHECK_DISCRIMINANT,
- ERR_R_MALLOC_FAILURE);
+ ERR_raise(ERR_LIB_EC, ERR_R_BN_LIB);
goto err;
}
}
if (order == NULL)
goto err;
- if (group->meth->field_decode) {
+ if (group->meth->field_decode != NULL) {
if (!group->meth->field_decode(group, a, group->a, ctx))
goto err;
if (!group->meth->field_decode(group, b, group->b, ctx))
ret = 1;
err:
- if (ctx != NULL)
- BN_CTX_end(ctx);
+ BN_CTX_end(ctx);
BN_CTX_free(new_ctx);
return ret;
}
-int ec_GFp_simple_point_init(EC_POINT *point)
+int ossl_ec_GFp_simple_point_init(EC_POINT *point)
{
point->X = BN_new();
point->Y = BN_new();
return 1;
}
-void ec_GFp_simple_point_finish(EC_POINT *point)
+void ossl_ec_GFp_simple_point_finish(EC_POINT *point)
{
BN_free(point->X);
BN_free(point->Y);
BN_free(point->Z);
}
-void ec_GFp_simple_point_clear_finish(EC_POINT *point)
+void ossl_ec_GFp_simple_point_clear_finish(EC_POINT *point)
{
BN_clear_free(point->X);
BN_clear_free(point->Y);
point->Z_is_one = 0;
}
-int ec_GFp_simple_point_copy(EC_POINT *dest, const EC_POINT *src)
+int ossl_ec_GFp_simple_point_copy(EC_POINT *dest, const EC_POINT *src)
{
if (!BN_copy(dest->X, src->X))
return 0;
return 1;
}
-int ec_GFp_simple_point_set_to_infinity(const EC_GROUP *group,
- EC_POINT *point)
+int ossl_ec_GFp_simple_point_set_to_infinity(const EC_GROUP *group,
+ EC_POINT *point)
{
point->Z_is_one = 0;
BN_zero(point->Z);
return 1;
}
-int ec_GFp_simple_set_Jprojective_coordinates_GFp(const EC_GROUP *group,
- EC_POINT *point,
- const BIGNUM *x,
- const BIGNUM *y,
- const BIGNUM *z,
- BN_CTX *ctx)
+int ossl_ec_GFp_simple_set_Jprojective_coordinates_GFp(const EC_GROUP *group,
+ EC_POINT *point,
+ const BIGNUM *x,
+ const BIGNUM *y,
+ const BIGNUM *z,
+ BN_CTX *ctx)
{
BN_CTX *new_ctx = NULL;
int ret = 0;
if (ctx == NULL) {
- ctx = new_ctx = BN_CTX_new();
+ ctx = new_ctx = BN_CTX_new_ex(group->libctx);
if (ctx == NULL)
return 0;
}
return ret;
}
-int ec_GFp_simple_get_Jprojective_coordinates_GFp(const EC_GROUP *group,
- const EC_POINT *point,
- BIGNUM *x, BIGNUM *y,
- BIGNUM *z, BN_CTX *ctx)
+int ossl_ec_GFp_simple_get_Jprojective_coordinates_GFp(const EC_GROUP *group,
+ const EC_POINT *point,
+ BIGNUM *x, BIGNUM *y,
+ BIGNUM *z, BN_CTX *ctx)
{
BN_CTX *new_ctx = NULL;
int ret = 0;
- if (group->meth->field_decode != 0) {
+ if (group->meth->field_decode != NULL) {
if (ctx == NULL) {
- ctx = new_ctx = BN_CTX_new();
+ ctx = new_ctx = BN_CTX_new_ex(group->libctx);
if (ctx == NULL)
return 0;
}
return ret;
}
-int ec_GFp_simple_point_set_affine_coordinates(const EC_GROUP *group,
- EC_POINT *point,
- const BIGNUM *x,
- const BIGNUM *y, BN_CTX *ctx)
+int ossl_ec_GFp_simple_point_set_affine_coordinates(const EC_GROUP *group,
+ EC_POINT *point,
+ const BIGNUM *x,
+ const BIGNUM *y, BN_CTX *ctx)
{
if (x == NULL || y == NULL) {
/*
* unlike for projective coordinates, we do not tolerate this
*/
- ECerr(EC_F_EC_GFP_SIMPLE_POINT_SET_AFFINE_COORDINATES,
- ERR_R_PASSED_NULL_PARAMETER);
+ ERR_raise(ERR_LIB_EC, ERR_R_PASSED_NULL_PARAMETER);
return 0;
}
BN_value_one(), ctx);
}
-int ec_GFp_simple_point_get_affine_coordinates(const EC_GROUP *group,
- const EC_POINT *point,
- BIGNUM *x, BIGNUM *y,
- BN_CTX *ctx)
+int ossl_ec_GFp_simple_point_get_affine_coordinates(const EC_GROUP *group,
+ const EC_POINT *point,
+ BIGNUM *x, BIGNUM *y,
+ BN_CTX *ctx)
{
BN_CTX *new_ctx = NULL;
BIGNUM *Z, *Z_1, *Z_2, *Z_3;
int ret = 0;
if (EC_POINT_is_at_infinity(group, point)) {
- ECerr(EC_F_EC_GFP_SIMPLE_POINT_GET_AFFINE_COORDINATES,
- EC_R_POINT_AT_INFINITY);
+ ERR_raise(ERR_LIB_EC, EC_R_POINT_AT_INFINITY);
return 0;
}
if (ctx == NULL) {
- ctx = new_ctx = BN_CTX_new();
+ ctx = new_ctx = BN_CTX_new_ex(group->libctx);
if (ctx == NULL)
return 0;
}
/* transform (X, Y, Z) into (x, y) := (X/Z^2, Y/Z^3) */
- if (group->meth->field_decode) {
+ if (group->meth->field_decode != NULL) {
if (!group->meth->field_decode(group, Z, point->Z, ctx))
goto err;
Z_ = Z;
}
if (BN_is_one(Z_)) {
- if (group->meth->field_decode) {
+ if (group->meth->field_decode != NULL) {
if (x != NULL) {
if (!group->meth->field_decode(group, x, point->X, ctx))
goto err;
}
}
} else {
- if (!BN_mod_inverse(Z_1, Z_, group->field, ctx)) {
- ECerr(EC_F_EC_GFP_SIMPLE_POINT_GET_AFFINE_COORDINATES,
- ERR_R_BN_LIB);
+ if (!group->meth->field_inv(group, Z_1, Z_, ctx)) {
+ ERR_raise(ERR_LIB_EC, ERR_R_BN_LIB);
goto err;
}
- if (group->meth->field_encode == 0) {
+ if (group->meth->field_encode == NULL) {
/* field_sqr works on standard representation */
if (!group->meth->field_sqr(group, Z_2, Z_1, ctx))
goto err;
}
if (y != NULL) {
- if (group->meth->field_encode == 0) {
+ if (group->meth->field_encode == NULL) {
/*
* field_mul works on standard representation
*/
return ret;
}
-int ec_GFp_simple_add(const EC_GROUP *group, EC_POINT *r, const EC_POINT *a,
- const EC_POINT *b, BN_CTX *ctx)
+int ossl_ec_GFp_simple_add(const EC_GROUP *group, EC_POINT *r, const EC_POINT *a,
+ const EC_POINT *b, BN_CTX *ctx)
{
int (*field_mul) (const EC_GROUP *, BIGNUM *, const BIGNUM *,
const BIGNUM *, BN_CTX *);
p = group->field;
if (ctx == NULL) {
- ctx = new_ctx = BN_CTX_new();
+ ctx = new_ctx = BN_CTX_new_ex(group->libctx);
if (ctx == NULL)
return 0;
}
ret = 1;
end:
- if (ctx) /* otherwise we already called BN_CTX_end */
- BN_CTX_end(ctx);
+ BN_CTX_end(ctx);
BN_CTX_free(new_ctx);
return ret;
}
-int ec_GFp_simple_dbl(const EC_GROUP *group, EC_POINT *r, const EC_POINT *a,
- BN_CTX *ctx)
+int ossl_ec_GFp_simple_dbl(const EC_GROUP *group, EC_POINT *r, const EC_POINT *a,
+ BN_CTX *ctx)
{
int (*field_mul) (const EC_GROUP *, BIGNUM *, const BIGNUM *,
const BIGNUM *, BN_CTX *);
p = group->field;
if (ctx == NULL) {
- ctx = new_ctx = BN_CTX_new();
+ ctx = new_ctx = BN_CTX_new_ex(group->libctx);
if (ctx == NULL)
return 0;
}
return ret;
}
-int ec_GFp_simple_invert(const EC_GROUP *group, EC_POINT *point, BN_CTX *ctx)
+int ossl_ec_GFp_simple_invert(const EC_GROUP *group, EC_POINT *point,
+ BN_CTX *ctx)
{
if (EC_POINT_is_at_infinity(group, point) || BN_is_zero(point->Y))
/* point is its own inverse */
return BN_usub(point->Y, group->field, point->Y);
}
-int ec_GFp_simple_is_at_infinity(const EC_GROUP *group, const EC_POINT *point)
+int ossl_ec_GFp_simple_is_at_infinity(const EC_GROUP *group,
+ const EC_POINT *point)
{
return BN_is_zero(point->Z);
}
-int ec_GFp_simple_is_on_curve(const EC_GROUP *group, const EC_POINT *point,
- BN_CTX *ctx)
+int ossl_ec_GFp_simple_is_on_curve(const EC_GROUP *group, const EC_POINT *point,
+ BN_CTX *ctx)
{
int (*field_mul) (const EC_GROUP *, BIGNUM *, const BIGNUM *,
const BIGNUM *, BN_CTX *);
p = group->field;
if (ctx == NULL) {
- ctx = new_ctx = BN_CTX_new();
+ ctx = new_ctx = BN_CTX_new_ex(group->libctx);
if (ctx == NULL)
return -1;
}
return ret;
}
-int ec_GFp_simple_cmp(const EC_GROUP *group, const EC_POINT *a,
- const EC_POINT *b, BN_CTX *ctx)
+int ossl_ec_GFp_simple_cmp(const EC_GROUP *group, const EC_POINT *a,
+ const EC_POINT *b, BN_CTX *ctx)
{
/*-
* return values:
field_sqr = group->meth->field_sqr;
if (ctx == NULL) {
- ctx = new_ctx = BN_CTX_new();
+ ctx = new_ctx = BN_CTX_new_ex(group->libctx);
if (ctx == NULL)
return -1;
}
return ret;
}
-int ec_GFp_simple_make_affine(const EC_GROUP *group, EC_POINT *point,
- BN_CTX *ctx)
+int ossl_ec_GFp_simple_make_affine(const EC_GROUP *group, EC_POINT *point,
+ BN_CTX *ctx)
{
BN_CTX *new_ctx = NULL;
BIGNUM *x, *y;
return 1;
if (ctx == NULL) {
- ctx = new_ctx = BN_CTX_new();
+ ctx = new_ctx = BN_CTX_new_ex(group->libctx);
if (ctx == NULL)
return 0;
}
if (y == NULL)
goto err;
- if (!EC_POINT_get_affine_coordinates_GFp(group, point, x, y, ctx))
+ if (!EC_POINT_get_affine_coordinates(group, point, x, y, ctx))
goto err;
- if (!EC_POINT_set_affine_coordinates_GFp(group, point, x, y, ctx))
+ if (!EC_POINT_set_affine_coordinates(group, point, x, y, ctx))
goto err;
if (!point->Z_is_one) {
- ECerr(EC_F_EC_GFP_SIMPLE_MAKE_AFFINE, ERR_R_INTERNAL_ERROR);
+ ERR_raise(ERR_LIB_EC, ERR_R_INTERNAL_ERROR);
goto err;
}
return ret;
}
-int ec_GFp_simple_points_make_affine(const EC_GROUP *group, size_t num,
- EC_POINT *points[], BN_CTX *ctx)
+int ossl_ec_GFp_simple_points_make_affine(const EC_GROUP *group, size_t num,
+ EC_POINT *points[], BN_CTX *ctx)
{
BN_CTX *new_ctx = NULL;
BIGNUM *tmp, *tmp_Z;
return 1;
if (ctx == NULL) {
- ctx = new_ctx = BN_CTX_new();
+ ctx = new_ctx = BN_CTX_new_ex(group->libctx);
if (ctx == NULL)
return 0;
}
* points[i]->Z by its inverse.
*/
- if (!BN_mod_inverse(tmp, prod_Z[num - 1], group->field, ctx)) {
- ECerr(EC_F_EC_GFP_SIMPLE_POINTS_MAKE_AFFINE, ERR_R_BN_LIB);
+ if (!group->meth->field_inv(group, tmp, prod_Z[num - 1], ctx)) {
+ ERR_raise(ERR_LIB_EC, ERR_R_BN_LIB);
goto err;
}
- if (group->meth->field_encode != 0) {
+ if (group->meth->field_encode != NULL) {
/*
* In the Montgomery case, we just turned R*H (representing H) into
* 1/(R*H), but we need R*(1/H) (representing 1/H); i.e. we need to
return ret;
}
-int ec_GFp_simple_field_mul(const EC_GROUP *group, BIGNUM *r, const BIGNUM *a,
- const BIGNUM *b, BN_CTX *ctx)
+int ossl_ec_GFp_simple_field_mul(const EC_GROUP *group, BIGNUM *r, const BIGNUM *a,
+ const BIGNUM *b, BN_CTX *ctx)
{
return BN_mod_mul(r, a, b, group->field, ctx);
}
-int ec_GFp_simple_field_sqr(const EC_GROUP *group, BIGNUM *r, const BIGNUM *a,
- BN_CTX *ctx)
+int ossl_ec_GFp_simple_field_sqr(const EC_GROUP *group, BIGNUM *r, const BIGNUM *a,
+ BN_CTX *ctx)
{
return BN_mod_sqr(r, a, group->field, ctx);
}
+/*-
+ * Computes the multiplicative inverse of a in GF(p), storing the result in r.
+ * If a is zero (or equivalent), you'll get an EC_R_CANNOT_INVERT error.
+ * Since we don't have a Mont structure here, SCA hardening is with blinding.
+ * NB: "a" must be in _decoded_ form. (i.e. field_decode must precede.)
+ */
+int ossl_ec_GFp_simple_field_inv(const EC_GROUP *group, BIGNUM *r,
+ const BIGNUM *a, BN_CTX *ctx)
+{
+ BIGNUM *e = NULL;
+ BN_CTX *new_ctx = NULL;
+ int ret = 0;
+
+ if (ctx == NULL
+ && (ctx = new_ctx = BN_CTX_secure_new_ex(group->libctx)) == NULL)
+ return 0;
+
+ BN_CTX_start(ctx);
+ if ((e = BN_CTX_get(ctx)) == NULL)
+ goto err;
+
+ do {
+ if (!BN_priv_rand_range_ex(e, group->field, 0, ctx))
+ goto err;
+ } while (BN_is_zero(e));
+
+ /* r := a * e */
+ if (!group->meth->field_mul(group, r, a, e, ctx))
+ goto err;
+ /* r := 1/(a * e) */
+ if (!BN_mod_inverse(r, r, group->field, ctx)) {
+ ERR_raise(ERR_LIB_EC, EC_R_CANNOT_INVERT);
+ goto err;
+ }
+ /* r := e/(a * e) = 1/a */
+ if (!group->meth->field_mul(group, r, r, e, ctx))
+ goto err;
+
+ ret = 1;
+
+ err:
+ BN_CTX_end(ctx);
+ BN_CTX_free(new_ctx);
+ return ret;
+}
+
/*-
* Apply randomization of EC point projective coordinates:
*
- * (X, Y ,Z ) = (lambda^2*X, lambda^3*Y, lambda*Z)
- * lambda = [1,group->field)
+ * (X, Y, Z) = (lambda^2*X, lambda^3*Y, lambda*Z)
+ * lambda = [1, group->field)
*
*/
-int ec_GFp_simple_blind_coordinates(const EC_GROUP *group, EC_POINT *p,
- BN_CTX *ctx)
+int ossl_ec_GFp_simple_blind_coordinates(const EC_GROUP *group, EC_POINT *p,
+ BN_CTX *ctx)
{
int ret = 0;
BIGNUM *lambda = NULL;
lambda = BN_CTX_get(ctx);
temp = BN_CTX_get(ctx);
if (temp == NULL) {
- ECerr(EC_F_EC_GFP_SIMPLE_BLIND_COORDINATES, ERR_R_MALLOC_FAILURE);
- goto err;
+ ERR_raise(ERR_LIB_EC, ERR_R_BN_LIB);
+ goto end;
}
- /* make sure lambda is not zero */
+ /*-
+ * Make sure lambda is not zero.
+ * If the RNG fails, we cannot blind but nevertheless want
+ * code to continue smoothly and not clobber the error stack.
+ */
do {
- if (!BN_priv_rand_range(lambda, group->field)) {
- ECerr(EC_F_EC_GFP_SIMPLE_BLIND_COORDINATES, ERR_R_BN_LIB);
- goto err;
+ ERR_set_mark();
+ ret = BN_priv_rand_range_ex(lambda, group->field, 0, ctx);
+ ERR_pop_to_mark();
+ if (ret == 0) {
+ ret = 1;
+ goto end;
}
} while (BN_is_zero(lambda));
+ /* if field_encode defined convert between representations */
+ if ((group->meth->field_encode != NULL
+ && !group->meth->field_encode(group, lambda, lambda, ctx))
+ || !group->meth->field_mul(group, p->Z, p->Z, lambda, ctx)
+ || !group->meth->field_sqr(group, temp, lambda, ctx)
+ || !group->meth->field_mul(group, p->X, p->X, temp, ctx)
+ || !group->meth->field_mul(group, temp, temp, lambda, ctx)
+ || !group->meth->field_mul(group, p->Y, p->Y, temp, ctx))
+ goto end;
+
+ p->Z_is_one = 0;
+ ret = 1;
+
+ end:
+ BN_CTX_end(ctx);
+ return ret;
+}
+
+/*-
+ * Input:
+ * - p: affine coordinates
+ *
+ * Output:
+ * - s := p, r := 2p: blinded projective (homogeneous) coordinates
+ *
+ * For doubling we use Formula 3 from Izu-Takagi "A fast parallel elliptic curve
+ * multiplication resistant against side channel attacks" appendix, described at
+ * https://hyperelliptic.org/EFD/g1p/auto-shortw-xz.html#doubling-dbl-2002-it-2
+ * simplified for Z1=1.
+ *
+ * Blinding uses the equivalence relation (\lambda X, \lambda Y, \lambda Z)
+ * for any non-zero \lambda that holds for projective (homogeneous) coords.
+ */
+int ossl_ec_GFp_simple_ladder_pre(const EC_GROUP *group,
+ EC_POINT *r, EC_POINT *s,
+ EC_POINT *p, BN_CTX *ctx)
+{
+ BIGNUM *t1, *t2, *t3, *t4, *t5 = NULL;
+
+ t1 = s->Z;
+ t2 = r->Z;
+ t3 = s->X;
+ t4 = r->X;
+ t5 = s->Y;
+
+ if (!p->Z_is_one /* r := 2p */
+ || !group->meth->field_sqr(group, t3, p->X, ctx)
+ || !BN_mod_sub_quick(t4, t3, group->a, group->field)
+ || !group->meth->field_sqr(group, t4, t4, ctx)
+ || !group->meth->field_mul(group, t5, p->X, group->b, ctx)
+ || !BN_mod_lshift_quick(t5, t5, 3, group->field)
+ /* r->X coord output */
+ || !BN_mod_sub_quick(r->X, t4, t5, group->field)
+ || !BN_mod_add_quick(t1, t3, group->a, group->field)
+ || !group->meth->field_mul(group, t2, p->X, t1, ctx)
+ || !BN_mod_add_quick(t2, group->b, t2, group->field)
+ /* r->Z coord output */
+ || !BN_mod_lshift_quick(r->Z, t2, 2, group->field))
+ return 0;
+
+ /* make sure lambda (r->Y here for storage) is not zero */
+ do {
+ if (!BN_priv_rand_range_ex(r->Y, group->field, 0, ctx))
+ return 0;
+ } while (BN_is_zero(r->Y));
+
+ /* make sure lambda (s->Z here for storage) is not zero */
+ do {
+ if (!BN_priv_rand_range_ex(s->Z, group->field, 0, ctx))
+ return 0;
+ } while (BN_is_zero(s->Z));
+
/* if field_encode defined convert between representations */
if (group->meth->field_encode != NULL
- && !group->meth->field_encode(group, lambda, lambda, ctx))
- goto err;
- if (!group->meth->field_mul(group, p->Z, p->Z, lambda, ctx))
- goto err;
- if (!group->meth->field_sqr(group, temp, lambda, ctx))
- goto err;
- if (!group->meth->field_mul(group, p->X, p->X, temp, ctx))
- goto err;
- if (!group->meth->field_mul(group, temp, temp, lambda, ctx))
+ && (!group->meth->field_encode(group, r->Y, r->Y, ctx)
+ || !group->meth->field_encode(group, s->Z, s->Z, ctx)))
+ return 0;
+
+ /* blind r and s independently */
+ if (!group->meth->field_mul(group, r->Z, r->Z, r->Y, ctx)
+ || !group->meth->field_mul(group, r->X, r->X, r->Y, ctx)
+ || !group->meth->field_mul(group, s->X, p->X, s->Z, ctx)) /* s := p */
+ return 0;
+
+ r->Z_is_one = 0;
+ s->Z_is_one = 0;
+
+ return 1;
+}
+
+/*-
+ * Input:
+ * - s, r: projective (homogeneous) coordinates
+ * - p: affine coordinates
+ *
+ * Output:
+ * - s := r + s, r := 2r: projective (homogeneous) coordinates
+ *
+ * Differential addition-and-doubling using Eq. (9) and (10) from Izu-Takagi
+ * "A fast parallel elliptic curve multiplication resistant against side channel
+ * attacks", as described at
+ * https://hyperelliptic.org/EFD/g1p/auto-shortw-xz.html#ladder-mladd-2002-it-4
+ */
+int ossl_ec_GFp_simple_ladder_step(const EC_GROUP *group,
+ EC_POINT *r, EC_POINT *s,
+ EC_POINT *p, BN_CTX *ctx)
+{
+ int ret = 0;
+ BIGNUM *t0, *t1, *t2, *t3, *t4, *t5, *t6 = NULL;
+
+ BN_CTX_start(ctx);
+ t0 = BN_CTX_get(ctx);
+ t1 = BN_CTX_get(ctx);
+ t2 = BN_CTX_get(ctx);
+ t3 = BN_CTX_get(ctx);
+ t4 = BN_CTX_get(ctx);
+ t5 = BN_CTX_get(ctx);
+ t6 = BN_CTX_get(ctx);
+
+ if (t6 == NULL
+ || !group->meth->field_mul(group, t6, r->X, s->X, ctx)
+ || !group->meth->field_mul(group, t0, r->Z, s->Z, ctx)
+ || !group->meth->field_mul(group, t4, r->X, s->Z, ctx)
+ || !group->meth->field_mul(group, t3, r->Z, s->X, ctx)
+ || !group->meth->field_mul(group, t5, group->a, t0, ctx)
+ || !BN_mod_add_quick(t5, t6, t5, group->field)
+ || !BN_mod_add_quick(t6, t3, t4, group->field)
+ || !group->meth->field_mul(group, t5, t6, t5, ctx)
+ || !group->meth->field_sqr(group, t0, t0, ctx)
+ || !BN_mod_lshift_quick(t2, group->b, 2, group->field)
+ || !group->meth->field_mul(group, t0, t2, t0, ctx)
+ || !BN_mod_lshift1_quick(t5, t5, group->field)
+ || !BN_mod_sub_quick(t3, t4, t3, group->field)
+ /* s->Z coord output */
+ || !group->meth->field_sqr(group, s->Z, t3, ctx)
+ || !group->meth->field_mul(group, t4, s->Z, p->X, ctx)
+ || !BN_mod_add_quick(t0, t0, t5, group->field)
+ /* s->X coord output */
+ || !BN_mod_sub_quick(s->X, t0, t4, group->field)
+ || !group->meth->field_sqr(group, t4, r->X, ctx)
+ || !group->meth->field_sqr(group, t5, r->Z, ctx)
+ || !group->meth->field_mul(group, t6, t5, group->a, ctx)
+ || !BN_mod_add_quick(t1, r->X, r->Z, group->field)
+ || !group->meth->field_sqr(group, t1, t1, ctx)
+ || !BN_mod_sub_quick(t1, t1, t4, group->field)
+ || !BN_mod_sub_quick(t1, t1, t5, group->field)
+ || !BN_mod_sub_quick(t3, t4, t6, group->field)
+ || !group->meth->field_sqr(group, t3, t3, ctx)
+ || !group->meth->field_mul(group, t0, t5, t1, ctx)
+ || !group->meth->field_mul(group, t0, t2, t0, ctx)
+ /* r->X coord output */
+ || !BN_mod_sub_quick(r->X, t3, t0, group->field)
+ || !BN_mod_add_quick(t3, t4, t6, group->field)
+ || !group->meth->field_sqr(group, t4, t5, ctx)
+ || !group->meth->field_mul(group, t4, t4, t2, ctx)
+ || !group->meth->field_mul(group, t1, t1, t3, ctx)
+ || !BN_mod_lshift1_quick(t1, t1, group->field)
+ /* r->Z coord output */
+ || !BN_mod_add_quick(r->Z, t4, t1, group->field))
goto err;
- if (!group->meth->field_mul(group, p->Y, p->Y, temp, ctx))
+
+ ret = 1;
+
+ err:
+ BN_CTX_end(ctx);
+ return ret;
+}
+
+/*-
+ * Input:
+ * - s, r: projective (homogeneous) coordinates
+ * - p: affine coordinates
+ *
+ * Output:
+ * - r := (x,y): affine coordinates
+ *
+ * Recovers the y-coordinate of r using Eq. (8) from Brier-Joye, "Weierstrass
+ * Elliptic Curves and Side-Channel Attacks", modified to work in mixed
+ * projective coords, i.e. p is affine and (r,s) in projective (homogeneous)
+ * coords, and return r in affine coordinates.
+ *
+ * X4 = two*Y1*X2*Z3*Z2;
+ * Y4 = two*b*Z3*SQR(Z2) + Z3*(a*Z2+X1*X2)*(X1*Z2+X2) - X3*SQR(X1*Z2-X2);
+ * Z4 = two*Y1*Z3*SQR(Z2);
+ *
+ * Z4 != 0 because:
+ * - Z2==0 implies r is at infinity (handled by the BN_is_zero(r->Z) branch);
+ * - Z3==0 implies s is at infinity (handled by the BN_is_zero(s->Z) branch);
+ * - Y1==0 implies p has order 2, so either r or s are infinity and handled by
+ * one of the BN_is_zero(...) branches.
+ */
+int ossl_ec_GFp_simple_ladder_post(const EC_GROUP *group,
+ EC_POINT *r, EC_POINT *s,
+ EC_POINT *p, BN_CTX *ctx)
+{
+ int ret = 0;
+ BIGNUM *t0, *t1, *t2, *t3, *t4, *t5, *t6 = NULL;
+
+ if (BN_is_zero(r->Z))
+ return EC_POINT_set_to_infinity(group, r);
+
+ if (BN_is_zero(s->Z)) {
+ if (!EC_POINT_copy(r, p)
+ || !EC_POINT_invert(group, r, ctx))
+ return 0;
+ return 1;
+ }
+
+ BN_CTX_start(ctx);
+ t0 = BN_CTX_get(ctx);
+ t1 = BN_CTX_get(ctx);
+ t2 = BN_CTX_get(ctx);
+ t3 = BN_CTX_get(ctx);
+ t4 = BN_CTX_get(ctx);
+ t5 = BN_CTX_get(ctx);
+ t6 = BN_CTX_get(ctx);
+
+ if (t6 == NULL
+ || !BN_mod_lshift1_quick(t4, p->Y, group->field)
+ || !group->meth->field_mul(group, t6, r->X, t4, ctx)
+ || !group->meth->field_mul(group, t6, s->Z, t6, ctx)
+ || !group->meth->field_mul(group, t5, r->Z, t6, ctx)
+ || !BN_mod_lshift1_quick(t1, group->b, group->field)
+ || !group->meth->field_mul(group, t1, s->Z, t1, ctx)
+ || !group->meth->field_sqr(group, t3, r->Z, ctx)
+ || !group->meth->field_mul(group, t2, t3, t1, ctx)
+ || !group->meth->field_mul(group, t6, r->Z, group->a, ctx)
+ || !group->meth->field_mul(group, t1, p->X, r->X, ctx)
+ || !BN_mod_add_quick(t1, t1, t6, group->field)
+ || !group->meth->field_mul(group, t1, s->Z, t1, ctx)
+ || !group->meth->field_mul(group, t0, p->X, r->Z, ctx)
+ || !BN_mod_add_quick(t6, r->X, t0, group->field)
+ || !group->meth->field_mul(group, t6, t6, t1, ctx)
+ || !BN_mod_add_quick(t6, t6, t2, group->field)
+ || !BN_mod_sub_quick(t0, t0, r->X, group->field)
+ || !group->meth->field_sqr(group, t0, t0, ctx)
+ || !group->meth->field_mul(group, t0, t0, s->X, ctx)
+ || !BN_mod_sub_quick(t0, t6, t0, group->field)
+ || !group->meth->field_mul(group, t1, s->Z, t4, ctx)
+ || !group->meth->field_mul(group, t1, t3, t1, ctx)
+ || (group->meth->field_decode != NULL
+ && !group->meth->field_decode(group, t1, t1, ctx))
+ || !group->meth->field_inv(group, t1, t1, ctx)
+ || (group->meth->field_encode != NULL
+ && !group->meth->field_encode(group, t1, t1, ctx))
+ || !group->meth->field_mul(group, r->X, t5, t1, ctx)
+ || !group->meth->field_mul(group, r->Y, t0, t1, ctx))
goto err;
- p->Z_is_one = 0;
+ if (group->meth->field_set_to_one != NULL) {
+ if (!group->meth->field_set_to_one(group, r->Z, ctx))
+ goto err;
+ } else {
+ if (!BN_one(r->Z))
+ goto err;
+ }
+
+ r->Z_is_one = 1;
ret = 1;
err:
- BN_CTX_end(ctx);
- return ret;
+ BN_CTX_end(ctx);
+ return ret;
}