crypto/ec/ecp_mont.c

   1 /*
   2  * Copyright 2001-2018 The OpenSSL Project Authors. All Rights Reserved.
   3  * Copyright (c) 2002, Oracle and/or its affiliates. All rights reserved
   4  *
   5  * Licensed under the OpenSSL license (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
   9  */
  10
  11 #include <openssl/err.h>
  12
  13 #include "ec_lcl.h"
  14
  15 const EC_METHOD *EC_GFp_mont_method(void)
  16 {
  17     static const EC_METHOD ret = {
  18         EC_FLAGS_DEFAULT_OCT,
  19         NID_X9_62_prime_field,
  20         ec_GFp_mont_group_init,
  21         ec_GFp_mont_group_finish,
  22         ec_GFp_mont_group_clear_finish,
  23         ec_GFp_mont_group_copy,
  24         ec_GFp_mont_group_set_curve,
  25         ec_GFp_simple_group_get_curve,
  26         ec_GFp_simple_group_get_degree,
  27         ec_group_simple_order_bits,
  28         ec_GFp_simple_group_check_discriminant,
  29         ec_GFp_simple_point_init,
  30         ec_GFp_simple_point_finish,
  31         ec_GFp_simple_point_clear_finish,
  32         ec_GFp_simple_point_copy,
  33         ec_GFp_simple_point_set_to_infinity,
  34         ec_GFp_simple_set_Jprojective_coordinates_GFp,
  35         ec_GFp_simple_get_Jprojective_coordinates_GFp,
  36         ec_GFp_simple_point_set_affine_coordinates,
  37         ec_GFp_simple_point_get_affine_coordinates,
  38         0, 0, 0,
  39         ec_GFp_simple_add,
  40         ec_GFp_simple_dbl,
  41         ec_GFp_simple_invert,
  42         ec_GFp_simple_is_at_infinity,
  43         ec_GFp_simple_is_on_curve,
  44         ec_GFp_simple_cmp,
  45         ec_GFp_simple_make_affine,
  46         ec_GFp_simple_points_make_affine,
  47         0 /* mul */ ,
  48         0 /* precompute_mult */ ,
  49         0 /* have_precompute_mult */ ,
  50         ec_GFp_mont_field_mul,
  51         ec_GFp_mont_field_sqr,
  52         0 /* field_div */ ,
  53         ec_GFp_mont_field_encode,
  54         ec_GFp_mont_field_decode,
  55         ec_GFp_mont_field_set_to_one,
  56         ec_key_simple_priv2oct,
  57         ec_key_simple_oct2priv,
  58         0, /* set private */
  59         ec_key_simple_generate_key,
  60         ec_key_simple_check_key,
  61         ec_key_simple_generate_public_key,
  62         0, /* keycopy */
  63         0, /* keyfinish */
  64         ecdh_simple_compute_key,
  65         0, /* field_inverse_mod_ord */
  66         ec_GFp_simple_blind_coordinates
  67     };
  68
  69     return &ret;
  70 }
  71
  72 int ec_GFp_mont_group_init(EC_GROUP *group)
  73 {
  74     int ok;
  75
  76     ok = ec_GFp_simple_group_init(group);
  77     group->field_data1 = NULL;
  78     group->field_data2 = NULL;
  79     return ok;
  80 }
  81
  82 void ec_GFp_mont_group_finish(EC_GROUP *group)
  83 {
  84     BN_MONT_CTX_free(group->field_data1);
  85     group->field_data1 = NULL;
  86     BN_free(group->field_data2);
  87     group->field_data2 = NULL;
  88     ec_GFp_simple_group_finish(group);
  89 }
  90
  91 void ec_GFp_mont_group_clear_finish(EC_GROUP *group)
  92 {
  93     BN_MONT_CTX_free(group->field_data1);
  94     group->field_data1 = NULL;
  95     BN_clear_free(group->field_data2);
  96     group->field_data2 = NULL;
  97     ec_GFp_simple_group_clear_finish(group);
  98 }
  99
 100 int ec_GFp_mont_group_copy(EC_GROUP *dest, const EC_GROUP *src)
 101 {
 102     BN_MONT_CTX_free(dest->field_data1);
 103     dest->field_data1 = NULL;
 104     BN_clear_free(dest->field_data2);
 105     dest->field_data2 = NULL;
 106
 107     if (!ec_GFp_simple_group_copy(dest, src))
 108         return 0;
 109
 110     if (src->field_data1 != NULL) {
 111         dest->field_data1 = BN_MONT_CTX_new();
 112         if (dest->field_data1 == NULL)
 113             return 0;
 114         if (!BN_MONT_CTX_copy(dest->field_data1, src->field_data1))
 115             goto err;
 116     }
 117     if (src->field_data2 != NULL) {
 118         dest->field_data2 = BN_dup(src->field_data2);
 119         if (dest->field_data2 == NULL)
 120             goto err;
 121     }
 122
 123     return 1;
 124
 125  err:
 126     BN_MONT_CTX_free(dest->field_data1);
 127     dest->field_data1 = NULL;
 128     return 0;
 129 }
 130
 131 int ec_GFp_mont_group_set_curve(EC_GROUP *group, const BIGNUM *p,
 132                                 const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx)
 133 {
 134     BN_CTX *new_ctx = NULL;
 135     BN_MONT_CTX *mont = NULL;
 136     BIGNUM *one = NULL;
 137     int ret = 0;
 138
 139     BN_MONT_CTX_free(group->field_data1);
 140     group->field_data1 = NULL;
 141     BN_free(group->field_data2);
 142     group->field_data2 = NULL;
 143
 144     if (ctx == NULL) {
 145         ctx = new_ctx = BN_CTX_new();
 146         if (ctx == NULL)
 147             return 0;
 148     }
 149
 150     mont = BN_MONT_CTX_new();
 151     if (mont == NULL)
 152         goto err;
 153     if (!BN_MONT_CTX_set(mont, p, ctx)) {
 154         ECerr(EC_F_EC_GFP_MONT_GROUP_SET_CURVE, ERR_R_BN_LIB);
 155         goto err;
 156     }
 157     one = BN_new();
 158     if (one == NULL)
 159         goto err;
 160     if (!BN_to_montgomery(one, BN_value_one(), mont, ctx))
 161         goto err;
 162
 163     group->field_data1 = mont;
 164     mont = NULL;
 165     group->field_data2 = one;
 166     one = NULL;
 167
 168     ret = ec_GFp_simple_group_set_curve(group, p, a, b, ctx);
 169
 170     if (!ret) {
 171         BN_MONT_CTX_free(group->field_data1);
 172         group->field_data1 = NULL;
 173         BN_free(group->field_data2);
 174         group->field_data2 = NULL;
 175     }
 176
 177  err:
 178     BN_free(one);
 179     BN_CTX_free(new_ctx);
 180     BN_MONT_CTX_free(mont);
 181     return ret;
 182 }
 183
 184 int ec_GFp_mont_field_mul(const EC_GROUP *group, BIGNUM *r, const BIGNUM *a,
 185                           const BIGNUM *b, BN_CTX *ctx)
 186 {
 187     if (group->field_data1 == NULL) {
 188         ECerr(EC_F_EC_GFP_MONT_FIELD_MUL, EC_R_NOT_INITIALIZED);
 189         return 0;
 190     }
 191
 192     return BN_mod_mul_montgomery(r, a, b, group->field_data1, ctx);
 193 }
 194
 195 int ec_GFp_mont_field_sqr(const EC_GROUP *group, BIGNUM *r, const BIGNUM *a,
 196                           BN_CTX *ctx)
 197 {
 198     if (group->field_data1 == NULL) {
 199         ECerr(EC_F_EC_GFP_MONT_FIELD_SQR, EC_R_NOT_INITIALIZED);
 200         return 0;
 201     }
 202
 203     return BN_mod_mul_montgomery(r, a, a, group->field_data1, ctx);
 204 }
 205
 206 int ec_GFp_mont_field_encode(const EC_GROUP *group, BIGNUM *r,
 207                              const BIGNUM *a, BN_CTX *ctx)
 208 {
 209     if (group->field_data1 == NULL) {
 210         ECerr(EC_F_EC_GFP_MONT_FIELD_ENCODE, EC_R_NOT_INITIALIZED);
 211         return 0;
 212     }
 213
 214     return BN_to_montgomery(r, a, (BN_MONT_CTX *)group->field_data1, ctx);
 215 }
 216
 217 int ec_GFp_mont_field_decode(const EC_GROUP *group, BIGNUM *r,
 218                              const BIGNUM *a, BN_CTX *ctx)
 219 {
 220     if (group->field_data1 == NULL) {
 221         ECerr(EC_F_EC_GFP_MONT_FIELD_DECODE, EC_R_NOT_INITIALIZED);
 222         return 0;
 223     }
 224
 225     return BN_from_montgomery(r, a, group->field_data1, ctx);
 226 }
 227
 228 int ec_GFp_mont_field_set_to_one(const EC_GROUP *group, BIGNUM *r,
 229                                  BN_CTX *ctx)
 230 {
 231     if (group->field_data2 == NULL) {
 232         ECerr(EC_F_EC_GFP_MONT_FIELD_SET_TO_ONE, EC_R_NOT_INITIALIZED);
 233         return 0;
 234     }
 235
 236     if (!BN_copy(r, group->field_data2))
 237         return 0;
 238     return 1;
 239 }