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      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 (at) 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 (at) cryptsoft.com).  This product includes software written by Tim
     55  * Hudson (tjh (at) 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 <string.h>
     65 #include "ec_lcl.h"
     66 #include <openssl/err.h>
     67 #ifdef OPENSSL_FIPS
     68 #include <openssl/fips.h>
     69 #endif
     70 
     71 EC_KEY *EC_KEY_new(void)
     72 	{
     73 	EC_KEY *ret;
     74 
     75 	ret=(EC_KEY *)OPENSSL_malloc(sizeof(EC_KEY));
     76 	if (ret == NULL)
     77 		{
     78 		ECerr(EC_F_EC_KEY_NEW, ERR_R_MALLOC_FAILURE);
     79 		return(NULL);
     80 		}
     81 
     82 	ret->version = 1;
     83 	ret->flags = 0;
     84 	ret->group   = NULL;
     85 	ret->pub_key = NULL;
     86 	ret->priv_key= NULL;
     87 	ret->enc_flag= 0;
     88 	ret->conv_form = POINT_CONVERSION_UNCOMPRESSED;
     89 	ret->references= 1;
     90 	ret->method_data = NULL;
     91 	return(ret);
     92 	}
     93 
     94 EC_KEY *EC_KEY_new_by_curve_name(int nid)
     95 	{
     96 	EC_KEY *ret = EC_KEY_new();
     97 	if (ret == NULL)
     98 		return NULL;
     99 	ret->group = EC_GROUP_new_by_curve_name(nid);
    100 	if (ret->group == NULL)
    101 		{
    102 		EC_KEY_free(ret);
    103 		return NULL;
    104 		}
    105 	return ret;
    106 	}
    107 
    108 void EC_KEY_free(EC_KEY *r)
    109 	{
    110 	int i;
    111 
    112 	if (r == NULL) return;
    113 
    114 	i=CRYPTO_add(&r->references,-1,CRYPTO_LOCK_EC);
    115 #ifdef REF_PRINT
    116 	REF_PRINT("EC_KEY",r);
    117 #endif
    118 	if (i > 0) return;
    119 #ifdef REF_CHECK
    120 	if (i < 0)
    121 		{
    122 		fprintf(stderr,"EC_KEY_free, bad reference count\n");
    123 		abort();
    124 		}
    125 #endif
    126 
    127 	if (r->group    != NULL)
    128 		EC_GROUP_free(r->group);
    129 	if (r->pub_key  != NULL)
    130 		EC_POINT_free(r->pub_key);
    131 	if (r->priv_key != NULL)
    132 		BN_clear_free(r->priv_key);
    133 
    134 	EC_EX_DATA_free_all_data(&r->method_data);
    135 
    136 	OPENSSL_cleanse((void *)r, sizeof(EC_KEY));
    137 
    138 	OPENSSL_free(r);
    139 	}
    140 
    141 EC_KEY *EC_KEY_copy(EC_KEY *dest, const EC_KEY *src)
    142 	{
    143 	EC_EXTRA_DATA *d;
    144 
    145 	if (dest == NULL || src == NULL)
    146 		{
    147 		ECerr(EC_F_EC_KEY_COPY, ERR_R_PASSED_NULL_PARAMETER);
    148 		return NULL;
    149 		}
    150 	/* copy the parameters */
    151 	if (src->group)
    152 		{
    153 		const EC_METHOD *meth = EC_GROUP_method_of(src->group);
    154 		/* clear the old group */
    155 		if (dest->group)
    156 			EC_GROUP_free(dest->group);
    157 		dest->group = EC_GROUP_new(meth);
    158 		if (dest->group == NULL)
    159 			return NULL;
    160 		if (!EC_GROUP_copy(dest->group, src->group))
    161 			return NULL;
    162 		}
    163 	/*  copy the public key */
    164 	if (src->pub_key && src->group)
    165 		{
    166 		if (dest->pub_key)
    167 			EC_POINT_free(dest->pub_key);
    168 		dest->pub_key = EC_POINT_new(src->group);
    169 		if (dest->pub_key == NULL)
    170 			return NULL;
    171 		if (!EC_POINT_copy(dest->pub_key, src->pub_key))
    172 			return NULL;
    173 		}
    174 	/* copy the private key */
    175 	if (src->priv_key)
    176 		{
    177 		if (dest->priv_key == NULL)
    178 			{
    179 			dest->priv_key = BN_new();
    180 			if (dest->priv_key == NULL)
    181 				return NULL;
    182 			}
    183 		if (!BN_copy(dest->priv_key, src->priv_key))
    184 			return NULL;
    185 		}
    186 	/* copy method/extra data */
    187 	EC_EX_DATA_free_all_data(&dest->method_data);
    188 
    189 	for (d = src->method_data; d != NULL; d = d->next)
    190 		{
    191 		void *t = d->dup_func(d->data);
    192 
    193 		if (t == NULL)
    194 			return 0;
    195 		if (!EC_EX_DATA_set_data(&dest->method_data, t, d->dup_func, d->free_func, d->clear_free_func))
    196 			return 0;
    197 		}
    198 
    199 	/* copy the rest */
    200 	dest->enc_flag  = src->enc_flag;
    201 	dest->conv_form = src->conv_form;
    202 	dest->version   = src->version;
    203 	dest->flags = src->flags;
    204 
    205 	return dest;
    206 	}
    207 
    208 EC_KEY *EC_KEY_dup(const EC_KEY *ec_key)
    209 	{
    210 	EC_KEY *ret = EC_KEY_new();
    211 	if (ret == NULL)
    212 		return NULL;
    213 	if (EC_KEY_copy(ret, ec_key) == NULL)
    214 		{
    215 		EC_KEY_free(ret);
    216 		return NULL;
    217 		}
    218 	return ret;
    219 	}
    220 
    221 int EC_KEY_up_ref(EC_KEY *r)
    222 	{
    223 	int i = CRYPTO_add(&r->references, 1, CRYPTO_LOCK_EC);
    224 #ifdef REF_PRINT
    225 	REF_PRINT("EC_KEY",r);
    226 #endif
    227 #ifdef REF_CHECK
    228 	if (i < 2)
    229 		{
    230 		fprintf(stderr, "EC_KEY_up, bad reference count\n");
    231 		abort();
    232 		}
    233 #endif
    234 	return ((i > 1) ? 1 : 0);
    235 	}
    236 
    237 int EC_KEY_generate_key(EC_KEY *eckey)
    238 	{
    239 	int	ok = 0;
    240 	BN_CTX	*ctx = NULL;
    241 	BIGNUM	*priv_key = NULL, *order = NULL;
    242 	EC_POINT *pub_key = NULL;
    243 
    244 #ifdef OPENSSL_FIPS
    245 	if (FIPS_mode())
    246 		return FIPS_ec_key_generate_key(eckey);
    247 #endif
    248 
    249 	if (!eckey || !eckey->group)
    250 		{
    251 		ECerr(EC_F_EC_KEY_GENERATE_KEY, ERR_R_PASSED_NULL_PARAMETER);
    252 		return 0;
    253 		}
    254 
    255 	if ((order = BN_new()) == NULL) goto err;
    256 	if ((ctx = BN_CTX_new()) == NULL) goto err;
    257 
    258 	if (eckey->priv_key == NULL)
    259 		{
    260 		priv_key = BN_new();
    261 		if (priv_key == NULL)
    262 			goto err;
    263 		}
    264 	else
    265 		priv_key = eckey->priv_key;
    266 
    267 	if (!EC_GROUP_get_order(eckey->group, order, ctx))
    268 		goto err;
    269 
    270 	do
    271 		if (!BN_rand_range(priv_key, order))
    272 			goto err;
    273 	while (BN_is_zero(priv_key));
    274 
    275 	if (eckey->pub_key == NULL)
    276 		{
    277 		pub_key = EC_POINT_new(eckey->group);
    278 		if (pub_key == NULL)
    279 			goto err;
    280 		}
    281 	else
    282 		pub_key = eckey->pub_key;
    283 
    284 	if (!EC_POINT_mul(eckey->group, pub_key, priv_key, NULL, NULL, ctx))
    285 		goto err;
    286 
    287 	eckey->priv_key = priv_key;
    288 	eckey->pub_key  = pub_key;
    289 
    290 	ok=1;
    291 
    292 err:
    293 	if (order)
    294 		BN_free(order);
    295 	if (pub_key  != NULL && eckey->pub_key  == NULL)
    296 		EC_POINT_free(pub_key);
    297 	if (priv_key != NULL && eckey->priv_key == NULL)
    298 		BN_free(priv_key);
    299 	if (ctx != NULL)
    300 		BN_CTX_free(ctx);
    301 	return(ok);
    302 	}
    303 
    304 int EC_KEY_check_key(const EC_KEY *eckey)
    305 	{
    306 	int	ok   = 0;
    307 	BN_CTX	*ctx = NULL;
    308 	const BIGNUM	*order  = NULL;
    309 	EC_POINT *point = NULL;
    310 
    311 	if (!eckey || !eckey->group || !eckey->pub_key)
    312 		{
    313 		ECerr(EC_F_EC_KEY_CHECK_KEY, ERR_R_PASSED_NULL_PARAMETER);
    314 		return 0;
    315 		}
    316 
    317 	if (EC_POINT_is_at_infinity(eckey->group, eckey->pub_key))
    318 		{
    319 		ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_POINT_AT_INFINITY);
    320 		goto err;
    321 		}
    322 
    323 	if ((ctx = BN_CTX_new()) == NULL)
    324 		goto err;
    325 	if ((point = EC_POINT_new(eckey->group)) == NULL)
    326 		goto err;
    327 
    328 	/* testing whether the pub_key is on the elliptic curve */
    329 	if (!EC_POINT_is_on_curve(eckey->group, eckey->pub_key, ctx))
    330 		{
    331 		ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_POINT_IS_NOT_ON_CURVE);
    332 		goto err;
    333 		}
    334 	/* testing whether pub_key * order is the point at infinity */
    335 	order = &eckey->group->order;
    336 	if (BN_is_zero(order))
    337 		{
    338 		ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_INVALID_GROUP_ORDER);
    339 		goto err;
    340 		}
    341 	if (!EC_POINT_mul(eckey->group, point, NULL, eckey->pub_key, order, ctx))
    342 		{
    343 		ECerr(EC_F_EC_KEY_CHECK_KEY, ERR_R_EC_LIB);
    344 		goto err;
    345 		}
    346 	if (!EC_POINT_is_at_infinity(eckey->group, point))
    347 		{
    348 		ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_WRONG_ORDER);
    349 		goto err;
    350 		}
    351 	/* in case the priv_key is present :
    352 	 * check if generator * priv_key == pub_key
    353 	 */
    354 	if (eckey->priv_key)
    355 		{
    356 		if (BN_cmp(eckey->priv_key, order) >= 0)
    357 			{
    358 			ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_WRONG_ORDER);
    359 			goto err;
    360 			}
    361 		if (!EC_POINT_mul(eckey->group, point, eckey->priv_key,
    362 			NULL, NULL, ctx))
    363 			{
    364 			ECerr(EC_F_EC_KEY_CHECK_KEY, ERR_R_EC_LIB);
    365 			goto err;
    366 			}
    367 		if (EC_POINT_cmp(eckey->group, point, eckey->pub_key,
    368 			ctx) != 0)
    369 			{
    370 			ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_INVALID_PRIVATE_KEY);
    371 			goto err;
    372 			}
    373 		}
    374 	ok = 1;
    375 err:
    376 	if (ctx   != NULL)
    377 		BN_CTX_free(ctx);
    378 	if (point != NULL)
    379 		EC_POINT_free(point);
    380 	return(ok);
    381 	}
    382 
    383 int EC_KEY_set_public_key_affine_coordinates(EC_KEY *key, BIGNUM *x, BIGNUM *y)
    384 	{
    385 	BN_CTX *ctx = NULL;
    386 	BIGNUM *tx, *ty;
    387 	EC_POINT *point = NULL;
    388 	int ok = 0, tmp_nid, is_char_two = 0;
    389 
    390 	if (!key || !key->group || !x || !y)
    391 		{
    392 		ECerr(EC_F_EC_KEY_SET_PUBLIC_KEY_AFFINE_COORDINATES,
    393 						ERR_R_PASSED_NULL_PARAMETER);
    394 		return 0;
    395 		}
    396 	ctx = BN_CTX_new();
    397 	if (!ctx)
    398 		goto err;
    399 
    400 	point = EC_POINT_new(key->group);
    401 
    402 	if (!point)
    403 		goto err;
    404 
    405 	tmp_nid = EC_METHOD_get_field_type(EC_GROUP_method_of(key->group));
    406 
    407         if (tmp_nid == NID_X9_62_characteristic_two_field)
    408 		is_char_two = 1;
    409 
    410 	tx = BN_CTX_get(ctx);
    411 	ty = BN_CTX_get(ctx);
    412 #ifndef OPENSSL_NO_EC2M
    413 	if (is_char_two)
    414 		{
    415 		if (!EC_POINT_set_affine_coordinates_GF2m(key->group, point,
    416 								x, y, ctx))
    417 			goto err;
    418 		if (!EC_POINT_get_affine_coordinates_GF2m(key->group, point,
    419 								tx, ty, ctx))
    420 			goto err;
    421 		}
    422 	else
    423 #endif
    424 		{
    425 		if (!EC_POINT_set_affine_coordinates_GFp(key->group, point,
    426 								x, y, ctx))
    427 			goto err;
    428 		if (!EC_POINT_get_affine_coordinates_GFp(key->group, point,
    429 								tx, ty, ctx))
    430 			goto err;
    431 		}
    432 	/* Check if retrieved coordinates match originals: if not values
    433 	 * are out of range.
    434 	 */
    435 	if (BN_cmp(x, tx) || BN_cmp(y, ty))
    436 		{
    437 		ECerr(EC_F_EC_KEY_SET_PUBLIC_KEY_AFFINE_COORDINATES,
    438 			EC_R_COORDINATES_OUT_OF_RANGE);
    439 		goto err;
    440 		}
    441 
    442 	if (!EC_KEY_set_public_key(key, point))
    443 		goto err;
    444 
    445 	if (EC_KEY_check_key(key) == 0)
    446 		goto err;
    447 
    448 	ok = 1;
    449 
    450 	err:
    451 	if (ctx)
    452 		BN_CTX_free(ctx);
    453 	if (point)
    454 		EC_POINT_free(point);
    455 	return ok;
    456 
    457 	}
    458 
    459 const EC_GROUP *EC_KEY_get0_group(const EC_KEY *key)
    460 	{
    461 	return key->group;
    462 	}
    463 
    464 int EC_KEY_set_group(EC_KEY *key, const EC_GROUP *group)
    465 	{
    466 	if (key->group != NULL)
    467 		EC_GROUP_free(key->group);
    468 	key->group = EC_GROUP_dup(group);
    469 	return (key->group == NULL) ? 0 : 1;
    470 	}
    471 
    472 const BIGNUM *EC_KEY_get0_private_key(const EC_KEY *key)
    473 	{
    474 	return key->priv_key;
    475 	}
    476 
    477 int EC_KEY_set_private_key(EC_KEY *key, const BIGNUM *priv_key)
    478 	{
    479 	if (key->priv_key)
    480 		BN_clear_free(key->priv_key);
    481 	key->priv_key = BN_dup(priv_key);
    482 	return (key->priv_key == NULL) ? 0 : 1;
    483 	}
    484 
    485 const EC_POINT *EC_KEY_get0_public_key(const EC_KEY *key)
    486 	{
    487 	return key->pub_key;
    488 	}
    489 
    490 int EC_KEY_set_public_key(EC_KEY *key, const EC_POINT *pub_key)
    491 	{
    492 	if (key->pub_key != NULL)
    493 		EC_POINT_free(key->pub_key);
    494 	key->pub_key = EC_POINT_dup(pub_key, key->group);
    495 	return (key->pub_key == NULL) ? 0 : 1;
    496 	}
    497 
    498 unsigned int EC_KEY_get_enc_flags(const EC_KEY *key)
    499 	{
    500 	return key->enc_flag;
    501 	}
    502 
    503 void EC_KEY_set_enc_flags(EC_KEY *key, unsigned int flags)
    504 	{
    505 	key->enc_flag = flags;
    506 	}
    507 
    508 point_conversion_form_t EC_KEY_get_conv_form(const EC_KEY *key)
    509 	{
    510 	return key->conv_form;
    511 	}
    512 
    513 void EC_KEY_set_conv_form(EC_KEY *key, point_conversion_form_t cform)
    514 	{
    515 	key->conv_form = cform;
    516 	if (key->group != NULL)
    517 		EC_GROUP_set_point_conversion_form(key->group, cform);
    518 	}
    519 
    520 void *EC_KEY_get_key_method_data(EC_KEY *key,
    521 	void *(*dup_func)(void *), void (*free_func)(void *), void (*clear_free_func)(void *))
    522 	{
    523 	void *ret;
    524 
    525 	CRYPTO_r_lock(CRYPTO_LOCK_EC);
    526 	ret = EC_EX_DATA_get_data(key->method_data, dup_func, free_func, clear_free_func);
    527 	CRYPTO_r_unlock(CRYPTO_LOCK_EC);
    528 
    529 	return ret;
    530 	}
    531 
    532 void *EC_KEY_insert_key_method_data(EC_KEY *key, void *data,
    533 	void *(*dup_func)(void *), void (*free_func)(void *), void (*clear_free_func)(void *))
    534 	{
    535 	EC_EXTRA_DATA *ex_data;
    536 
    537 	CRYPTO_w_lock(CRYPTO_LOCK_EC);
    538 	ex_data = EC_EX_DATA_get_data(key->method_data, dup_func, free_func, clear_free_func);
    539 	if (ex_data == NULL)
    540 		EC_EX_DATA_set_data(&key->method_data, data, dup_func, free_func, clear_free_func);
    541 	CRYPTO_w_unlock(CRYPTO_LOCK_EC);
    542 
    543 	return ex_data;
    544 	}
    545 
    546 void EC_KEY_set_asn1_flag(EC_KEY *key, int flag)
    547 	{
    548 	if (key->group != NULL)
    549 		EC_GROUP_set_asn1_flag(key->group, flag);
    550 	}
    551 
    552 int EC_KEY_precompute_mult(EC_KEY *key, BN_CTX *ctx)
    553 	{
    554 	if (key->group == NULL)
    555 		return 0;
    556 	return EC_GROUP_precompute_mult(key->group, ctx);
    557 	}
    558 
    559 int EC_KEY_get_flags(const EC_KEY *key)
    560 	{
    561 	return key->flags;
    562 	}
    563 
    564 void EC_KEY_set_flags(EC_KEY *key, int flags)
    565 	{
    566 	key->flags |= flags;
    567 	}
    568 
    569 void EC_KEY_clear_flags(EC_KEY *key, int flags)
    570 	{
    571 	key->flags &= ~flags;
    572 	}
    573