crypto/ec/ecp_mont.c

   1 /*
   2  * Copyright 2001-2016 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     };
  66
  67     return &ret;
  68 }
  69
  70 int ec_GFp_mont_group_init(EC_GROUP *group)
  71 {
  72     int ok;
  73
  74     ok = ec_GFp_simple_group_init(group);
  75     group->field_data1 = NULL;
  76     group->field_data2 = NULL;
  77     return ok;
  78 }
  79
  80 void ec_GFp_mont_group_finish(EC_GROUP *group)
  81 {
  82     BN_MONT_CTX_free(group->field_data1);
  83     group->field_data1 = NULL;
  84     BN_free(group->field_data2);
  85     group->field_data2 = NULL;
  86     ec_GFp_simple_group_finish(group);
  87 }
  88
  89 void ec_GFp_mont_group_clear_finish(EC_GROUP *group)
  90 {
  91     BN_MONT_CTX_free(group->field_data1);
  92     group->field_data1 = NULL;
  93     BN_clear_free(group->field_data2);
  94     group->field_data2 = NULL;
  95     ec_GFp_simple_group_clear_finish(group);
  96 }
  97
  98 int ec_GFp_mont_group_copy(EC_GROUP *dest, const EC_GROUP *src)
  99 {
 100     BN_MONT_CTX_free(dest->field_data1);
 101     dest->field_data1 = NULL;
 102     BN_clear_free(dest->field_data2);
 103     dest->field_data2 = NULL;
 104
 105     if (!ec_GFp_simple_group_copy(dest, src))
 106         return 0;
 107
 108     if (src->field_data1 != NULL) {
 109         dest->field_data1 = BN_MONT_CTX_new();
 110         if (dest->field_data1 == NULL)
 111             return 0;
 112         if (!BN_MONT_CTX_copy(dest->field_data1, src->field_data1))
 113             goto err;
 114     }
 115     if (src->field_data2 != NULL) {
 116         dest->field_data2 = BN_dup(src->field_data2);
 117         if (dest->field_data2 == NULL)
 118             goto err;
 119     }
 120
 121     return 1;
 122
 123  err:
 124     BN_MONT_CTX_free(dest->field_data1);
 125     dest->field_data1 = NULL;
 126     return 0;
 127 }
 128
 129 int ec_GFp_mont_group_set_curve(EC_GROUP *group, const BIGNUM *p,
 130                                 const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx)
 131 {
 132     BN_CTX *new_ctx = NULL;
 133     BN_MONT_CTX *mont = NULL;
 134     BIGNUM *one = NULL;
 135     int ret = 0;
 136
 137     BN_MONT_CTX_free(group->field_data1);
 138     group->field_data1 = NULL;
 139     BN_free(group->field_data2);
 140     group->field_data2 = NULL;
 141
 142     if (ctx == NULL) {
 143         ctx = new_ctx = BN_CTX_new();
 144         if (ctx == NULL)
 145             return 0;
 146     }
 147
 148     mont = BN_MONT_CTX_new();
 149     if (mont == NULL)
 150         goto err;
 151     if (!BN_MONT_CTX_set(mont, p, ctx)) {
 152         ECerr(EC_F_EC_GFP_MONT_GROUP_SET_CURVE, ERR_R_BN_LIB);
 153         goto err;
 154     }
 155     one = BN_new();
 156     if (one == NULL)
 157         goto err;
 158     if (!BN_to_montgomery(one, BN_value_one(), mont, ctx))
 159         goto err;
 160
 161     group->field_data1 = mont;
 162     mont = NULL;
 163     group->field_data2 = one;
 164     one = NULL;
 165
 166     ret = ec_GFp_simple_group_set_curve(group, p, a, b, ctx);
 167
 168     if (!ret) {
 169         BN_MONT_CTX_free(group->field_data1);
 170         group->field_data1 = NULL;
 171         BN_free(group->field_data2);
 172         group->field_data2 = NULL;
 173     }
 174
 175  err:
 176     BN_free(one);
 177     BN_CTX_free(new_ctx);
 178     BN_MONT_CTX_free(mont);
 179     return ret;
 180 }
 181
 182 int ec_GFp_mont_field_mul(const EC_GROUP *group, BIGNUM *r, const BIGNUM *a,
 183                           const BIGNUM *b, BN_CTX *ctx)
 184 {
 185     if (group->field_data1 == NULL) {
 186         ECerr(EC_F_EC_GFP_MONT_FIELD_MUL, EC_R_NOT_INITIALIZED);
 187         return 0;
 188     }
 189
 190     return BN_mod_mul_montgomery(r, a, b, group->field_data1, ctx);
 191 }
 192
 193 int ec_GFp_mont_field_sqr(const EC_GROUP *group, BIGNUM *r, const BIGNUM *a,
 194                           BN_CTX *ctx)
 195 {
 196     if (group->field_data1 == NULL) {
 197         ECerr(EC_F_EC_GFP_MONT_FIELD_SQR, EC_R_NOT_INITIALIZED);
 198         return 0;
 199     }
 200
 201     return BN_mod_mul_montgomery(r, a, a, group->field_data1, ctx);
 202 }
 203
 204 int ec_GFp_mont_field_encode(const EC_GROUP *group, BIGNUM *r,
 205                              const BIGNUM *a, BN_CTX *ctx)
 206 {
 207     if (group->field_data1 == NULL) {
 208         ECerr(EC_F_EC_GFP_MONT_FIELD_ENCODE, EC_R_NOT_INITIALIZED);
 209         return 0;
 210     }
 211
 212     return BN_to_montgomery(r, a, (BN_MONT_CTX *)group->field_data1, ctx);
 213 }
 214
 215 int ec_GFp_mont_field_decode(const EC_GROUP *group, BIGNUM *r,
 216                              const BIGNUM *a, BN_CTX *ctx)
 217 {
 218     if (group->field_data1 == NULL) {
 219         ECerr(EC_F_EC_GFP_MONT_FIELD_DECODE, EC_R_NOT_INITIALIZED);
 220         return 0;
 221     }
 222
 223     return BN_from_montgomery(r, a, group->field_data1, ctx);
 224 }
 225
 226 int ec_GFp_mont_field_set_to_one(const EC_GROUP *group, BIGNUM *r,
 227                                  BN_CTX *ctx)
 228 {
 229     if (group->field_data2 == NULL) {
 230         ECerr(EC_F_EC_GFP_MONT_FIELD_SET_TO_ONE, EC_R_NOT_INITIALIZED);
 231         return 0;
 232     }
 233
 234     if (!BN_copy(r, group->field_data2))
 235         return 0;
 236     return 1;
 237 }