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_point_set_affine_coordinates,
41 ec_GFp_simple_point_get_affine_coordinates,
46 ec_GFp_simple_is_at_infinity,
47 ec_GFp_simple_is_on_curve,
49 ec_GFp_simple_make_affine,
50 ec_GFp_simple_points_make_affine,
52 0 /* precompute_mult */ ,
53 0 /* have_precompute_mult */ ,
54 ec_GFp_mont_field_mul,
55 ec_GFp_mont_field_sqr,
57 ec_GFp_mont_field_inv,
58 ec_GFp_mont_field_encode,
59 ec_GFp_mont_field_decode,
60 ec_GFp_mont_field_set_to_one,
61 ec_key_simple_priv2oct,
62 ec_key_simple_oct2priv,
64 ec_key_simple_generate_key,
65 ec_key_simple_check_key,
66 ec_key_simple_generate_public_key,
69 ecdh_simple_compute_key,
70 ecdsa_simple_sign_setup,
71 ecdsa_simple_sign_sig,
72 ecdsa_simple_verify_sig,
73 0, /* field_inverse_mod_ord */
74 ec_GFp_simple_blind_coordinates,
75 ec_GFp_simple_ladder_pre,
76 ec_GFp_simple_ladder_step,
77 ec_GFp_simple_ladder_post
83 int ec_GFp_mont_group_init(EC_GROUP *group)
87 ok = ec_GFp_simple_group_init(group);
88 group->field_data1 = NULL;
89 group->field_data2 = NULL;
93 void ec_GFp_mont_group_finish(EC_GROUP *group)
95 BN_MONT_CTX_free(group->field_data1);
96 group->field_data1 = NULL;
97 BN_free(group->field_data2);
98 group->field_data2 = NULL;
99 ec_GFp_simple_group_finish(group);
102 void ec_GFp_mont_group_clear_finish(EC_GROUP *group)
104 BN_MONT_CTX_free(group->field_data1);
105 group->field_data1 = NULL;
106 BN_clear_free(group->field_data2);
107 group->field_data2 = NULL;
108 ec_GFp_simple_group_clear_finish(group);
111 int ec_GFp_mont_group_copy(EC_GROUP *dest, const EC_GROUP *src)
113 BN_MONT_CTX_free(dest->field_data1);
114 dest->field_data1 = NULL;
115 BN_clear_free(dest->field_data2);
116 dest->field_data2 = NULL;
118 if (!ec_GFp_simple_group_copy(dest, src))
121 if (src->field_data1 != NULL) {
122 dest->field_data1 = BN_MONT_CTX_new();
123 if (dest->field_data1 == NULL)
125 if (!BN_MONT_CTX_copy(dest->field_data1, src->field_data1))
128 if (src->field_data2 != NULL) {
129 dest->field_data2 = BN_dup(src->field_data2);
130 if (dest->field_data2 == NULL)
137 BN_MONT_CTX_free(dest->field_data1);
138 dest->field_data1 = NULL;
142 int ec_GFp_mont_group_set_curve(EC_GROUP *group, const BIGNUM *p,
143 const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx)
145 BN_CTX *new_ctx = NULL;
146 BN_MONT_CTX *mont = NULL;
150 BN_MONT_CTX_free(group->field_data1);
151 group->field_data1 = NULL;
152 BN_free(group->field_data2);
153 group->field_data2 = NULL;
156 ctx = new_ctx = BN_CTX_new_ex(group->libctx);
161 mont = BN_MONT_CTX_new();
164 if (!BN_MONT_CTX_set(mont, p, ctx)) {
165 ECerr(EC_F_EC_GFP_MONT_GROUP_SET_CURVE, ERR_R_BN_LIB);
171 if (!BN_to_montgomery(one, BN_value_one(), mont, ctx))
174 group->field_data1 = mont;
176 group->field_data2 = one;
179 ret = ec_GFp_simple_group_set_curve(group, p, a, b, ctx);
182 BN_MONT_CTX_free(group->field_data1);
183 group->field_data1 = NULL;
184 BN_free(group->field_data2);
185 group->field_data2 = NULL;
190 BN_CTX_free(new_ctx);
191 BN_MONT_CTX_free(mont);
195 int ec_GFp_mont_field_mul(const EC_GROUP *group, BIGNUM *r, const BIGNUM *a,
196 const BIGNUM *b, BN_CTX *ctx)
198 if (group->field_data1 == NULL) {
199 ECerr(EC_F_EC_GFP_MONT_FIELD_MUL, EC_R_NOT_INITIALIZED);
203 return BN_mod_mul_montgomery(r, a, b, group->field_data1, ctx);
206 int ec_GFp_mont_field_sqr(const EC_GROUP *group, BIGNUM *r, const BIGNUM *a,
209 if (group->field_data1 == NULL) {
210 ECerr(EC_F_EC_GFP_MONT_FIELD_SQR, EC_R_NOT_INITIALIZED);
214 return BN_mod_mul_montgomery(r, a, a, group->field_data1, ctx);
218 * Computes the multiplicative inverse of a in GF(p), storing the result in r.
219 * If a is zero (or equivalent), you'll get a EC_R_CANNOT_INVERT error.
220 * We have a Mont structure, so SCA hardening is FLT inversion.
222 int ec_GFp_mont_field_inv(const EC_GROUP *group, BIGNUM *r, const BIGNUM *a,
226 BN_CTX *new_ctx = NULL;
229 if (group->field_data1 == NULL)
233 && (ctx = new_ctx = BN_CTX_secure_new_ex(group->libctx)) == NULL)
237 if ((e = BN_CTX_get(ctx)) == NULL)
240 /* Inverse in constant time with Fermats Little Theorem */
241 if (!BN_set_word(e, 2))
243 if (!BN_sub(e, group->field, e))
246 * Exponent e is public.
247 * No need for scatter-gather or BN_FLG_CONSTTIME.
249 if (!BN_mod_exp_mont(r, a, e, group->field, ctx, group->field_data1))
252 /* throw an error on zero */
254 ECerr(EC_F_EC_GFP_MONT_FIELD_INV, EC_R_CANNOT_INVERT);
262 BN_CTX_free(new_ctx);
266 int ec_GFp_mont_field_encode(const EC_GROUP *group, BIGNUM *r,
267 const BIGNUM *a, BN_CTX *ctx)
269 if (group->field_data1 == NULL) {
270 ECerr(EC_F_EC_GFP_MONT_FIELD_ENCODE, EC_R_NOT_INITIALIZED);
274 return BN_to_montgomery(r, a, (BN_MONT_CTX *)group->field_data1, ctx);
277 int ec_GFp_mont_field_decode(const EC_GROUP *group, BIGNUM *r,
278 const BIGNUM *a, BN_CTX *ctx)
280 if (group->field_data1 == NULL) {
281 ECerr(EC_F_EC_GFP_MONT_FIELD_DECODE, EC_R_NOT_INITIALIZED);
285 return BN_from_montgomery(r, a, group->field_data1, ctx);
288 int ec_GFp_mont_field_set_to_one(const EC_GROUP *group, BIGNUM *r,
291 if (group->field_data2 == NULL) {
292 ECerr(EC_F_EC_GFP_MONT_FIELD_SET_TO_ONE, EC_R_NOT_INITIALIZED);
296 if (!BN_copy(r, group->field_data2))