crypto/ec/ec_key.c

   1 /* crypto/ec/ec_key.c */
   2 /*
   3  * Written by Nils Larsch for the OpenSSL project.
   4  */
   5 /* ====================================================================
   6  * Copyright (c) 1998-2005 The OpenSSL Project.  All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  *
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  *
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in
  17  *    the documentation and/or other materials provided with the
  18  *    distribution.
  19  *
  20  * 3. All advertising materials mentioning features or use of this
  21  *    software must display the following acknowledgment:
  22  *    "This product includes software developed by the OpenSSL Project
  23  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
  24  *
  25  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  26  *    endorse or promote products derived from this software without
  27  *    prior written permission. For written permission, please contact
  28  *    openssl-core@openssl.org.
  29  *
  30  * 5. Products derived from this software may not be called "OpenSSL"
  31  *    nor may "OpenSSL" appear in their names without prior written
  32  *    permission of the OpenSSL Project.
  33  *
  34  * 6. Redistributions of any form whatsoever must retain the following
  35  *    acknowledgment:
  36  *    "This product includes software developed by the OpenSSL Project
  37  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
  38  *
  39  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  40  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  41  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  42  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  43  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  44  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  45  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  46  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  48  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  49  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  50  * OF THE POSSIBILITY OF SUCH DAMAGE.
  51  * ====================================================================
  52  *
  53  * This product includes cryptographic software written by Eric Young
  54  * (eay@cryptsoft.com).  This product includes software written by Tim
  55  * Hudson (tjh@cryptsoft.com).
  56  *
  57  */
  58 /* ====================================================================
  59  * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
  60  * Portions originally developed by SUN MICROSYSTEMS, INC., and
  61  * contributed to the OpenSSL project.
  62  */
  63
  64 #include <internal/cryptlib.h>
  65 #include <string.h>
  66 #include "ec_lcl.h"
  67 #include <openssl/err.h>
  68
  69 EC_KEY *EC_KEY_new(void)
  70 {
  71     return EC_KEY_new_method(NULL);
  72 }
  73
  74 EC_KEY *EC_KEY_new_by_curve_name(int nid)
  75 {
  76     EC_KEY *ret = EC_KEY_new();
  77     if (ret == NULL)
  78         return NULL;
  79     ret->group = EC_GROUP_new_by_curve_name(nid);
  80     if (ret->group == NULL) {
  81         EC_KEY_free(ret);
  82         return NULL;
  83     }
  84     return ret;
  85 }
  86
  87 void EC_KEY_free(EC_KEY *r)
  88 {
  89     int i;
  90
  91     if (r == NULL)
  92         return;
  93
  94     i = CRYPTO_add(&r->references, -1, CRYPTO_LOCK_EC);
  95 #ifdef REF_PRINT
  96     REF_PRINT("EC_KEY", r);
  97 #endif
  98     if (i > 0)
  99         return;
 100 #ifdef REF_CHECK
 101     if (i < 0) {
 102         fprintf(stderr, "EC_KEY_free, bad reference count\n");
 103         abort();
 104     }
 105 #endif
 106
 107     EC_GROUP_free(r->group);
 108     EC_POINT_free(r->pub_key);
 109     BN_clear_free(r->priv_key);
 110
 111     EC_EX_DATA_free_all_data(&r->method_data);
 112
 113     OPENSSL_clear_free((void *)r, sizeof(EC_KEY));
 114 }
 115
 116 EC_KEY *EC_KEY_copy(EC_KEY *dest, const EC_KEY *src)
 117 {
 118     EC_EXTRA_DATA *d;
 119
 120     if (dest == NULL || src == NULL) {
 121         ECerr(EC_F_EC_KEY_COPY, ERR_R_PASSED_NULL_PARAMETER);
 122         return NULL;
 123     }
 124     /* copy the parameters */
 125     if (src->group) {
 126         const EC_METHOD *meth = EC_GROUP_method_of(src->group);
 127         /* clear the old group */
 128         EC_GROUP_free(dest->group);
 129         dest->group = EC_GROUP_new(meth);
 130         if (dest->group == NULL)
 131             return NULL;
 132         if (!EC_GROUP_copy(dest->group, src->group))
 133             return NULL;
 134     }
 135     /*  copy the public key */
 136     if (src->pub_key && src->group) {
 137         EC_POINT_free(dest->pub_key);
 138         dest->pub_key = EC_POINT_new(src->group);
 139         if (dest->pub_key == NULL)
 140             return NULL;
 141         if (!EC_POINT_copy(dest->pub_key, src->pub_key))
 142             return NULL;
 143     }
 144     /* copy the private key */
 145     if (src->priv_key) {
 146         if (dest->priv_key == NULL) {
 147             dest->priv_key = BN_new();
 148             if (dest->priv_key == NULL)
 149                 return NULL;
 150         }
 151         if (!BN_copy(dest->priv_key, src->priv_key))
 152             return NULL;
 153     }
 154     /* copy method/extra data */
 155     EC_EX_DATA_free_all_data(&dest->method_data);
 156
 157     for (d = src->method_data; d != NULL; d = d->next) {
 158         void *t = d->dup_func(d->data);
 159
 160         if (t == NULL)
 161             return 0;
 162         if (!EC_EX_DATA_set_data
 163             (&dest->method_data, t, d->dup_func, d->free_func,
 164              d->clear_free_func))
 165             return 0;
 166     }
 167
 168     /* copy the rest */
 169     dest->enc_flag = src->enc_flag;
 170     dest->conv_form = src->conv_form;
 171     dest->version = src->version;
 172     dest->flags = src->flags;
 173
 174     return dest;
 175 }
 176
 177 EC_KEY *EC_KEY_dup(const EC_KEY *ec_key)
 178 {
 179     EC_KEY *ret = EC_KEY_new();
 180     if (ret == NULL)
 181         return NULL;
 182     if (EC_KEY_copy(ret, ec_key) == NULL) {
 183         EC_KEY_free(ret);
 184         return NULL;
 185     }
 186     return ret;
 187 }
 188
 189 int EC_KEY_up_ref(EC_KEY *r)
 190 {
 191     int i = CRYPTO_add(&r->references, 1, CRYPTO_LOCK_EC);
 192 #ifdef REF_PRINT
 193     REF_PRINT("EC_KEY", r);
 194 #endif
 195 #ifdef REF_CHECK
 196     if (i < 2) {
 197         fprintf(stderr, "EC_KEY_up, bad reference count\n");
 198         abort();
 199     }
 200 #endif
 201     return ((i > 1) ? 1 : 0);
 202 }
 203
 204 int EC_KEY_generate_key(EC_KEY *eckey)
 205 {
 206     int ok = 0;
 207     BN_CTX *ctx = NULL;
 208     BIGNUM *priv_key = NULL, *order = NULL;
 209     EC_POINT *pub_key = NULL;
 210
 211     if (!eckey || !eckey->group) {
 212         ECerr(EC_F_EC_KEY_GENERATE_KEY, ERR_R_PASSED_NULL_PARAMETER);
 213         return 0;
 214     }
 215
 216     if ((order = BN_new()) == NULL)
 217         goto err;
 218     if ((ctx = BN_CTX_new()) == NULL)
 219         goto err;
 220
 221     if (eckey->priv_key == NULL) {
 222         priv_key = BN_new();
 223         if (priv_key == NULL)
 224             goto err;
 225     } else
 226         priv_key = eckey->priv_key;
 227
 228     if (!EC_GROUP_get_order(eckey->group, order, ctx))
 229         goto err;
 230
 231     do
 232         if (!BN_rand_range(priv_key, order))
 233             goto err;
 234     while (BN_is_zero(priv_key)) ;
 235
 236     if (eckey->pub_key == NULL) {
 237         pub_key = EC_POINT_new(eckey->group);
 238         if (pub_key == NULL)
 239             goto err;
 240     } else
 241         pub_key = eckey->pub_key;
 242
 243     if (!EC_POINT_mul(eckey->group, pub_key, priv_key, NULL, NULL, ctx))
 244         goto err;
 245
 246     eckey->priv_key = priv_key;
 247     eckey->pub_key = pub_key;
 248
 249     ok = 1;
 250
 251  err:
 252     BN_free(order);
 253     if (eckey->pub_key == NULL)
 254         EC_POINT_free(pub_key);
 255     if (eckey->priv_key != priv_key)
 256         BN_free(priv_key);
 257     BN_CTX_free(ctx);
 258     return (ok);
 259 }
 260
 261 int EC_KEY_check_key(const EC_KEY *eckey)
 262 {
 263     int ok = 0;
 264     BN_CTX *ctx = NULL;
 265     const BIGNUM *order = NULL;
 266     EC_POINT *point = NULL;
 267
 268     if (!eckey || !eckey->group || !eckey->pub_key) {
 269         ECerr(EC_F_EC_KEY_CHECK_KEY, ERR_R_PASSED_NULL_PARAMETER);
 270         return 0;
 271     }
 272
 273     if (EC_POINT_is_at_infinity(eckey->group, eckey->pub_key)) {
 274         ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_POINT_AT_INFINITY);
 275         goto err;
 276     }
 277
 278     if ((ctx = BN_CTX_new()) == NULL)
 279         goto err;
 280     if ((point = EC_POINT_new(eckey->group)) == NULL)
 281         goto err;
 282
 283     /* testing whether the pub_key is on the elliptic curve */
 284     if (EC_POINT_is_on_curve(eckey->group, eckey->pub_key, ctx) <= 0) {
 285         ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_POINT_IS_NOT_ON_CURVE);
 286         goto err;
 287     }
 288     /* testing whether pub_key * order is the point at infinity */
 289     order = eckey->group->order;
 290     if (BN_is_zero(order)) {
 291         ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_INVALID_GROUP_ORDER);
 292         goto err;
 293     }
 294     if (!EC_POINT_mul(eckey->group, point, NULL, eckey->pub_key, order, ctx)) {
 295         ECerr(EC_F_EC_KEY_CHECK_KEY, ERR_R_EC_LIB);
 296         goto err;
 297     }
 298     if (!EC_POINT_is_at_infinity(eckey->group, point)) {
 299         ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_WRONG_ORDER);
 300         goto err;
 301     }
 302     /*
 303      * in case the priv_key is present : check if generator * priv_key ==
 304      * pub_key
 305      */
 306     if (eckey->priv_key) {
 307         if (BN_cmp(eckey->priv_key, order) >= 0) {
 308             ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_WRONG_ORDER);
 309             goto err;
 310         }
 311         if (!EC_POINT_mul(eckey->group, point, eckey->priv_key,
 312                           NULL, NULL, ctx)) {
 313             ECerr(EC_F_EC_KEY_CHECK_KEY, ERR_R_EC_LIB);
 314             goto err;
 315         }
 316         if (EC_POINT_cmp(eckey->group, point, eckey->pub_key, ctx) != 0) {
 317             ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_INVALID_PRIVATE_KEY);
 318             goto err;
 319         }
 320     }
 321     ok = 1;
 322  err:
 323     BN_CTX_free(ctx);
 324     EC_POINT_free(point);
 325     return (ok);
 326 }
 327
 328 int EC_KEY_set_public_key_affine_coordinates(EC_KEY *key, BIGNUM *x,
 329                                              BIGNUM *y)
 330 {
 331     BN_CTX *ctx = NULL;
 332     BIGNUM *tx, *ty;
 333     EC_POINT *point = NULL;
 334     int ok = 0;
 335 #ifndef OPENSSL_NO_EC2M
 336     int tmp_nid, is_char_two = 0;
 337 #endif
 338
 339     if (!key || !key->group || !x || !y) {
 340         ECerr(EC_F_EC_KEY_SET_PUBLIC_KEY_AFFINE_COORDINATES,
 341               ERR_R_PASSED_NULL_PARAMETER);
 342         return 0;
 343     }
 344     ctx = BN_CTX_new();
 345     if (ctx == NULL)
 346         goto err;
 347
 348     point = EC_POINT_new(key->group);
 349
 350     if (point == NULL)
 351         goto err;
 352
 353     tx = BN_CTX_get(ctx);
 354     ty = BN_CTX_get(ctx);
 355
 356 #ifndef OPENSSL_NO_EC2M
 357     tmp_nid = EC_METHOD_get_field_type(EC_GROUP_method_of(key->group));
 358
 359     if (tmp_nid == NID_X9_62_characteristic_two_field)
 360         is_char_two = 1;
 361
 362     if (is_char_two) {
 363         if (!EC_POINT_set_affine_coordinates_GF2m(key->group, point,
 364                                                   x, y, ctx))
 365             goto err;
 366         if (!EC_POINT_get_affine_coordinates_GF2m(key->group, point,
 367                                                   tx, ty, ctx))
 368             goto err;
 369     } else
 370 #endif
 371     {
 372         if (!EC_POINT_set_affine_coordinates_GFp(key->group, point,
 373                                                  x, y, ctx))
 374             goto err;
 375         if (!EC_POINT_get_affine_coordinates_GFp(key->group, point,
 376                                                  tx, ty, ctx))
 377             goto err;
 378     }
 379     /*
 380      * Check if retrieved coordinates match originals and are less than field
 381      * order: if not values are out of range.
 382      */
 383     if (BN_cmp(x, tx) || BN_cmp(y, ty)
 384         || (BN_cmp(x, key->group->field) >= 0)
 385         || (BN_cmp(y, key->group->field) >= 0)) {
 386         ECerr(EC_F_EC_KEY_SET_PUBLIC_KEY_AFFINE_COORDINATES,
 387               EC_R_COORDINATES_OUT_OF_RANGE);
 388         goto err;
 389     }
 390
 391     if (!EC_KEY_set_public_key(key, point))
 392         goto err;
 393
 394     if (EC_KEY_check_key(key) == 0)
 395         goto err;
 396
 397     ok = 1;
 398
 399  err:
 400     BN_CTX_free(ctx);
 401     EC_POINT_free(point);
 402     return ok;
 403
 404 }
 405
 406 const EC_GROUP *EC_KEY_get0_group(const EC_KEY *key)
 407 {
 408     return key->group;
 409 }
 410
 411 int EC_KEY_set_group(EC_KEY *key, const EC_GROUP *group)
 412 {
 413     EC_GROUP_free(key->group);
 414     key->group = EC_GROUP_dup(group);
 415     return (key->group == NULL) ? 0 : 1;
 416 }
 417
 418 const BIGNUM *EC_KEY_get0_private_key(const EC_KEY *key)
 419 {
 420     return key->priv_key;
 421 }
 422
 423 int EC_KEY_set_private_key(EC_KEY *key, const BIGNUM *priv_key)
 424 {
 425     BN_clear_free(key->priv_key);
 426     key->priv_key = BN_dup(priv_key);
 427     return (key->priv_key == NULL) ? 0 : 1;
 428 }
 429
 430 const EC_POINT *EC_KEY_get0_public_key(const EC_KEY *key)
 431 {
 432     return key->pub_key;
 433 }
 434
 435 int EC_KEY_set_public_key(EC_KEY *key, const EC_POINT *pub_key)
 436 {
 437     EC_POINT_free(key->pub_key);
 438     key->pub_key = EC_POINT_dup(pub_key, key->group);
 439     return (key->pub_key == NULL) ? 0 : 1;
 440 }
 441
 442 unsigned int EC_KEY_get_enc_flags(const EC_KEY *key)
 443 {
 444     return key->enc_flag;
 445 }
 446
 447 void EC_KEY_set_enc_flags(EC_KEY *key, unsigned int flags)
 448 {
 449     key->enc_flag = flags;
 450 }
 451
 452 point_conversion_form_t EC_KEY_get_conv_form(const EC_KEY *key)
 453 {
 454     return key->conv_form;
 455 }
 456
 457 void EC_KEY_set_conv_form(EC_KEY *key, point_conversion_form_t cform)
 458 {
 459     key->conv_form = cform;
 460     if (key->group != NULL)
 461         EC_GROUP_set_point_conversion_form(key->group, cform);
 462 }
 463
 464 void *EC_KEY_get_key_method_data(EC_KEY *key,
 465                                  void *(*dup_func) (void *),
 466                                  void (*free_func) (void *),
 467                                  void (*clear_free_func) (void *))
 468 {
 469     void *ret;
 470
 471     CRYPTO_r_lock(CRYPTO_LOCK_EC);
 472     ret =
 473         EC_EX_DATA_get_data(key->method_data, dup_func, free_func,
 474                             clear_free_func);
 475     CRYPTO_r_unlock(CRYPTO_LOCK_EC);
 476
 477     return ret;
 478 }
 479
 480 void *EC_KEY_insert_key_method_data(EC_KEY *key, void *data,
 481                                     void *(*dup_func) (void *),
 482                                     void (*free_func) (void *),
 483                                     void (*clear_free_func) (void *))
 484 {
 485     EC_EXTRA_DATA *ex_data;
 486
 487     CRYPTO_w_lock(CRYPTO_LOCK_EC);
 488     ex_data =
 489         EC_EX_DATA_get_data(key->method_data, dup_func, free_func,
 490                             clear_free_func);
 491     if (ex_data == NULL)
 492         EC_EX_DATA_set_data(&key->method_data, data, dup_func, free_func,
 493                             clear_free_func);
 494     CRYPTO_w_unlock(CRYPTO_LOCK_EC);
 495
 496     return ex_data;
 497 }
 498
 499 void EC_KEY_set_asn1_flag(EC_KEY *key, int flag)
 500 {
 501     if (key->group != NULL)
 502         EC_GROUP_set_asn1_flag(key->group, flag);
 503 }
 504
 505 int EC_KEY_precompute_mult(EC_KEY *key, BN_CTX *ctx)
 506 {
 507     if (key->group == NULL)
 508         return 0;
 509     return EC_GROUP_precompute_mult(key->group, ctx);
 510 }
 511
 512 int EC_KEY_get_flags(const EC_KEY *key)
 513 {
 514     return key->flags;
 515 }
 516
 517 void EC_KEY_set_flags(EC_KEY *key, int flags)
 518 {
 519     key->flags |= flags;
 520 }
 521
 522 void EC_KEY_clear_flags(EC_KEY *key, int flags)
 523 {
 524     key->flags &= ~flags;
 525 }