crypto/ec/ecp_mont.c

   1 /*
   2  * Copyright 2001-2016 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the OpenSSL license (the "License").  You may not use
   5  * this file except in compliance with the License.  You can obtain a copy
   6  * in the file LICENSE in the source distribution or at
   7  * https://www.openssl.org/source/license.html
   8  */
   9
  10 /* ====================================================================
  11  * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
  12  * Portions of this software developed by SUN MICROSYSTEMS, INC.,
  13  * and contributed to the OpenSSL project.
  14  */
  15
  16 #include <openssl/err.h>
  17
  18 #include "ec_lcl.h"
  19
  20 const EC_METHOD *EC_GFp_mont_method(void)
  21 {
  22     static const EC_METHOD ret = {
  23         EC_FLAGS_DEFAULT_OCT,
  24         NID_X9_62_prime_field,
  25         ec_GFp_mont_group_init,
  26         ec_GFp_mont_group_finish,
  27         ec_GFp_mont_group_clear_finish,
  28         ec_GFp_mont_group_copy,
  29         ec_GFp_mont_group_set_curve,
  30         ec_GFp_simple_group_get_curve,
  31         ec_GFp_simple_group_get_degree,
  32         ec_group_simple_order_bits,
  33         ec_GFp_simple_group_check_discriminant,
  34         ec_GFp_simple_point_init,
  35         ec_GFp_simple_point_finish,
  36         ec_GFp_simple_point_clear_finish,
  37         ec_GFp_simple_point_copy,
  38         ec_GFp_simple_point_set_to_infinity,
  39         ec_GFp_simple_set_Jprojective_coordinates_GFp,
  40         ec_GFp_simple_get_Jprojective_coordinates_GFp,
  41         ec_GFp_simple_point_set_affine_coordinates,
  42         ec_GFp_simple_point_get_affine_coordinates,
  43         0, 0, 0,
  44         ec_GFp_simple_add,
  45         ec_GFp_simple_dbl,
  46         ec_GFp_simple_invert,
  47         ec_GFp_simple_is_at_infinity,
  48         ec_GFp_simple_is_on_curve,
  49         ec_GFp_simple_cmp,
  50         ec_GFp_simple_make_affine,
  51         ec_GFp_simple_points_make_affine,
  52         0 /* mul */ ,
  53         0 /* precompute_mult */ ,
  54         0 /* have_precompute_mult */ ,
  55         ec_GFp_mont_field_mul,
  56         ec_GFp_mont_field_sqr,
  57         0 /* field_div */ ,
  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,
  63         0, /* set private */
  64         ec_key_simple_generate_key,
  65         ec_key_simple_check_key,
  66         ec_key_simple_generate_public_key,
  67         0, /* keycopy */
  68         0, /* keyfinish */
  69         ecdh_simple_compute_key
  70     };
  71
  72     return &ret;
  73 }
  74
  75 int ec_GFp_mont_group_init(EC_GROUP *group)
  76 {
  77     int ok;
  78
  79     ok = ec_GFp_simple_group_init(group);
  80     group->field_data1 = NULL;
  81     group->field_data2 = NULL;
  82     return ok;
  83 }
  84
  85 void ec_GFp_mont_group_finish(EC_GROUP *group)
  86 {
  87     BN_MONT_CTX_free(group->field_data1);
  88     group->field_data1 = NULL;
  89     BN_free(group->field_data2);
  90     group->field_data2 = NULL;
  91     ec_GFp_simple_group_finish(group);
  92 }
  93
  94 void ec_GFp_mont_group_clear_finish(EC_GROUP *group)
  95 {
  96     BN_MONT_CTX_free(group->field_data1);
  97     group->field_data1 = NULL;
  98     BN_clear_free(group->field_data2);
  99     group->field_data2 = NULL;
 100     ec_GFp_simple_group_clear_finish(group);
 101 }
 102
 103 int ec_GFp_mont_group_copy(EC_GROUP *dest, const EC_GROUP *src)
 104 {
 105     BN_MONT_CTX_free(dest->field_data1);
 106     dest->field_data1 = NULL;
 107     BN_clear_free(dest->field_data2);
 108     dest->field_data2 = NULL;
 109
 110     if (!ec_GFp_simple_group_copy(dest, src))
 111         return 0;
 112
 113     if (src->field_data1 != NULL) {
 114         dest->field_data1 = BN_MONT_CTX_new();
 115         if (dest->field_data1 == NULL)
 116             return 0;
 117         if (!BN_MONT_CTX_copy(dest->field_data1, src->field_data1))
 118             goto err;
 119     }
 120     if (src->field_data2 != NULL) {
 121         dest->field_data2 = BN_dup(src->field_data2);
 122         if (dest->field_data2 == NULL)
 123             goto err;
 124     }
 125
 126     return 1;
 127
 128  err:
 129     BN_MONT_CTX_free(dest->field_data1);
 130     dest->field_data1 = NULL;
 131     return 0;
 132 }
 133
 134 int ec_GFp_mont_group_set_curve(EC_GROUP *group, const BIGNUM *p,
 135                                 const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx)
 136 {
 137     BN_CTX *new_ctx = NULL;
 138     BN_MONT_CTX *mont = NULL;
 139     BIGNUM *one = NULL;
 140     int ret = 0;
 141
 142     BN_MONT_CTX_free(group->field_data1);
 143     group->field_data1 = NULL;
 144     BN_free(group->field_data2);
 145     group->field_data2 = NULL;
 146
 147     if (ctx == NULL) {
 148         ctx = new_ctx = BN_CTX_new();
 149         if (ctx == NULL)
 150             return 0;
 151     }
 152
 153     mont = BN_MONT_CTX_new();
 154     if (mont == NULL)
 155         goto err;
 156     if (!BN_MONT_CTX_set(mont, p, ctx)) {
 157         ECerr(EC_F_EC_GFP_MONT_GROUP_SET_CURVE, ERR_R_BN_LIB);
 158         goto err;
 159     }
 160     one = BN_new();
 161     if (one == NULL)
 162         goto err;
 163     if (!BN_to_montgomery(one, BN_value_one(), mont, ctx))
 164         goto err;
 165
 166     group->field_data1 = mont;
 167     mont = NULL;
 168     group->field_data2 = one;
 169     one = NULL;
 170
 171     ret = ec_GFp_simple_group_set_curve(group, p, a, b, ctx);
 172
 173     if (!ret) {
 174         BN_MONT_CTX_free(group->field_data1);
 175         group->field_data1 = NULL;
 176         BN_free(group->field_data2);
 177         group->field_data2 = NULL;
 178     }
 179
 180  err:
 181     BN_CTX_free(new_ctx);
 182     BN_MONT_CTX_free(mont);
 183     return ret;
 184 }
 185
 186 int ec_GFp_mont_field_mul(const EC_GROUP *group, BIGNUM *r, const BIGNUM *a,
 187                           const BIGNUM *b, BN_CTX *ctx)
 188 {
 189     if (group->field_data1 == NULL) {
 190         ECerr(EC_F_EC_GFP_MONT_FIELD_MUL, EC_R_NOT_INITIALIZED);
 191         return 0;
 192     }
 193
 194     return BN_mod_mul_montgomery(r, a, b, group->field_data1, ctx);
 195 }
 196
 197 int ec_GFp_mont_field_sqr(const EC_GROUP *group, BIGNUM *r, const BIGNUM *a,
 198                           BN_CTX *ctx)
 199 {
 200     if (group->field_data1 == NULL) {
 201         ECerr(EC_F_EC_GFP_MONT_FIELD_SQR, EC_R_NOT_INITIALIZED);
 202         return 0;
 203     }
 204
 205     return BN_mod_mul_montgomery(r, a, a, group->field_data1, ctx);
 206 }
 207
 208 int ec_GFp_mont_field_encode(const EC_GROUP *group, BIGNUM *r,
 209                              const BIGNUM *a, BN_CTX *ctx)
 210 {
 211     if (group->field_data1 == NULL) {
 212         ECerr(EC_F_EC_GFP_MONT_FIELD_ENCODE, EC_R_NOT_INITIALIZED);
 213         return 0;
 214     }
 215
 216     return BN_to_montgomery(r, a, (BN_MONT_CTX *)group->field_data1, ctx);
 217 }
 218
 219 int ec_GFp_mont_field_decode(const EC_GROUP *group, BIGNUM *r,
 220                              const BIGNUM *a, BN_CTX *ctx)
 221 {
 222     if (group->field_data1 == NULL) {
 223         ECerr(EC_F_EC_GFP_MONT_FIELD_DECODE, EC_R_NOT_INITIALIZED);
 224         return 0;
 225     }
 226
 227     return BN_from_montgomery(r, a, group->field_data1, ctx);
 228 }
 229
 230 int ec_GFp_mont_field_set_to_one(const EC_GROUP *group, BIGNUM *r,
 231                                  BN_CTX *ctx)
 232 {
 233     if (group->field_data2 == NULL) {
 234         ECerr(EC_F_EC_GFP_MONT_FIELD_SET_TO_ONE, EC_R_NOT_INITIALIZED);
 235         return 0;
 236     }
 237
 238     if (!BN_copy(r, group->field_data2))
 239         return 0;
 240     return 1;
 241 }