2 * Copyright 2001-2018 The OpenSSL Project Authors. All Rights Reserved.
3 * Copyright (c) 2002, Oracle and/or its affiliates. All rights reserved
5 * Licensed under the Apache License 2.0 (the "License"). You may not use
6 * this file except in compliance with the License. You can obtain a copy
7 * in the file LICENSE in the source distribution or at
8 * https://www.openssl.org/source/license.html
12 * ECDSA low level APIs are deprecated for public use, but still ok for
15 #include "internal/deprecated.h"
17 #include <openssl/err.h>
21 const EC_METHOD *EC_GFp_mont_method(void)
23 static const EC_METHOD ret = {
25 NID_X9_62_prime_field,
26 ec_GFp_mont_group_init,
27 ec_GFp_mont_group_finish,
28 ec_GFp_mont_group_clear_finish,
29 ec_GFp_mont_group_copy,
30 ec_GFp_mont_group_set_curve,
31 ec_GFp_simple_group_get_curve,
32 ec_GFp_simple_group_get_degree,
33 ec_group_simple_order_bits,
34 ec_GFp_simple_group_check_discriminant,
35 ec_GFp_simple_point_init,
36 ec_GFp_simple_point_finish,
37 ec_GFp_simple_point_clear_finish,
38 ec_GFp_simple_point_copy,
39 ec_GFp_simple_point_set_to_infinity,
40 ec_GFp_simple_set_Jprojective_coordinates_GFp,
41 ec_GFp_simple_get_Jprojective_coordinates_GFp,
42 ec_GFp_simple_point_set_affine_coordinates,
43 ec_GFp_simple_point_get_affine_coordinates,
48 ec_GFp_simple_is_at_infinity,
49 ec_GFp_simple_is_on_curve,
51 ec_GFp_simple_make_affine,
52 ec_GFp_simple_points_make_affine,
54 0 /* precompute_mult */ ,
55 0 /* have_precompute_mult */ ,
56 ec_GFp_mont_field_mul,
57 ec_GFp_mont_field_sqr,
59 ec_GFp_mont_field_inv,
60 ec_GFp_mont_field_encode,
61 ec_GFp_mont_field_decode,
62 ec_GFp_mont_field_set_to_one,
63 ec_key_simple_priv2oct,
64 ec_key_simple_oct2priv,
66 ec_key_simple_generate_key,
67 ec_key_simple_check_key,
68 ec_key_simple_generate_public_key,
71 ecdh_simple_compute_key,
72 ecdsa_simple_sign_setup,
73 ecdsa_simple_sign_sig,
74 ecdsa_simple_verify_sig,
75 0, /* field_inverse_mod_ord */
76 ec_GFp_simple_blind_coordinates,
77 ec_GFp_simple_ladder_pre,
78 ec_GFp_simple_ladder_step,
79 ec_GFp_simple_ladder_post
85 int ec_GFp_mont_group_init(EC_GROUP *group)
89 ok = ec_GFp_simple_group_init(group);
90 group->field_data1 = NULL;
91 group->field_data2 = NULL;
95 void ec_GFp_mont_group_finish(EC_GROUP *group)
97 BN_MONT_CTX_free(group->field_data1);
98 group->field_data1 = NULL;
99 BN_free(group->field_data2);
100 group->field_data2 = NULL;
101 ec_GFp_simple_group_finish(group);
104 void ec_GFp_mont_group_clear_finish(EC_GROUP *group)
106 BN_MONT_CTX_free(group->field_data1);
107 group->field_data1 = NULL;
108 BN_clear_free(group->field_data2);
109 group->field_data2 = NULL;
110 ec_GFp_simple_group_clear_finish(group);
113 int ec_GFp_mont_group_copy(EC_GROUP *dest, const EC_GROUP *src)
115 BN_MONT_CTX_free(dest->field_data1);
116 dest->field_data1 = NULL;
117 BN_clear_free(dest->field_data2);
118 dest->field_data2 = NULL;
120 if (!ec_GFp_simple_group_copy(dest, src))
123 if (src->field_data1 != NULL) {
124 dest->field_data1 = BN_MONT_CTX_new();
125 if (dest->field_data1 == NULL)
127 if (!BN_MONT_CTX_copy(dest->field_data1, src->field_data1))
130 if (src->field_data2 != NULL) {
131 dest->field_data2 = BN_dup(src->field_data2);
132 if (dest->field_data2 == NULL)
139 BN_MONT_CTX_free(dest->field_data1);
140 dest->field_data1 = NULL;
144 int ec_GFp_mont_group_set_curve(EC_GROUP *group, const BIGNUM *p,
145 const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx)
147 BN_CTX *new_ctx = NULL;
148 BN_MONT_CTX *mont = NULL;
152 BN_MONT_CTX_free(group->field_data1);
153 group->field_data1 = NULL;
154 BN_free(group->field_data2);
155 group->field_data2 = NULL;
158 ctx = new_ctx = BN_CTX_new_ex(group->libctx);
163 mont = BN_MONT_CTX_new();
166 if (!BN_MONT_CTX_set(mont, p, ctx)) {
167 ECerr(EC_F_EC_GFP_MONT_GROUP_SET_CURVE, ERR_R_BN_LIB);
173 if (!BN_to_montgomery(one, BN_value_one(), mont, ctx))
176 group->field_data1 = mont;
178 group->field_data2 = one;
181 ret = ec_GFp_simple_group_set_curve(group, p, a, b, ctx);
184 BN_MONT_CTX_free(group->field_data1);
185 group->field_data1 = NULL;
186 BN_free(group->field_data2);
187 group->field_data2 = NULL;
192 BN_CTX_free(new_ctx);
193 BN_MONT_CTX_free(mont);
197 int ec_GFp_mont_field_mul(const EC_GROUP *group, BIGNUM *r, const BIGNUM *a,
198 const BIGNUM *b, BN_CTX *ctx)
200 if (group->field_data1 == NULL) {
201 ECerr(EC_F_EC_GFP_MONT_FIELD_MUL, EC_R_NOT_INITIALIZED);
205 return BN_mod_mul_montgomery(r, a, b, group->field_data1, ctx);
208 int ec_GFp_mont_field_sqr(const EC_GROUP *group, BIGNUM *r, const BIGNUM *a,
211 if (group->field_data1 == NULL) {
212 ECerr(EC_F_EC_GFP_MONT_FIELD_SQR, EC_R_NOT_INITIALIZED);
216 return BN_mod_mul_montgomery(r, a, a, group->field_data1, ctx);
220 * Computes the multiplicative inverse of a in GF(p), storing the result in r.
221 * If a is zero (or equivalent), you'll get a EC_R_CANNOT_INVERT error.
222 * We have a Mont structure, so SCA hardening is FLT inversion.
224 int ec_GFp_mont_field_inv(const EC_GROUP *group, BIGNUM *r, const BIGNUM *a,
228 BN_CTX *new_ctx = NULL;
231 if (group->field_data1 == NULL)
235 && (ctx = new_ctx = BN_CTX_secure_new_ex(group->libctx)) == NULL)
239 if ((e = BN_CTX_get(ctx)) == NULL)
242 /* Inverse in constant time with Fermats Little Theorem */
243 if (!BN_set_word(e, 2))
245 if (!BN_sub(e, group->field, e))
248 * Exponent e is public.
249 * No need for scatter-gather or BN_FLG_CONSTTIME.
251 if (!BN_mod_exp_mont(r, a, e, group->field, ctx, group->field_data1))
254 /* throw an error on zero */
256 ECerr(EC_F_EC_GFP_MONT_FIELD_INV, EC_R_CANNOT_INVERT);
264 BN_CTX_free(new_ctx);
268 int ec_GFp_mont_field_encode(const EC_GROUP *group, BIGNUM *r,
269 const BIGNUM *a, BN_CTX *ctx)
271 if (group->field_data1 == NULL) {
272 ECerr(EC_F_EC_GFP_MONT_FIELD_ENCODE, EC_R_NOT_INITIALIZED);
276 return BN_to_montgomery(r, a, (BN_MONT_CTX *)group->field_data1, ctx);
279 int ec_GFp_mont_field_decode(const EC_GROUP *group, BIGNUM *r,
280 const BIGNUM *a, BN_CTX *ctx)
282 if (group->field_data1 == NULL) {
283 ECerr(EC_F_EC_GFP_MONT_FIELD_DECODE, EC_R_NOT_INITIALIZED);
287 return BN_from_montgomery(r, a, group->field_data1, ctx);
290 int ec_GFp_mont_field_set_to_one(const EC_GROUP *group, BIGNUM *r,
293 if (group->field_data2 == NULL) {
294 ECerr(EC_F_EC_GFP_MONT_FIELD_SET_TO_ONE, EC_R_NOT_INITIALIZED);
298 if (!BN_copy(r, group->field_data2))