ec_key.c revision 04ef91b390dfcc6125913e2f2af502d23d7a5112 
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 <string.h>
65#include "ec_lcl.h"
66#include <openssl/err.h>
67#ifdef OPENSSL_FIPS
68#include <openssl/fips.h>
69#endif
70
71EC_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
94EC_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
108void 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
141EC_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
208EC_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
221int 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
237int 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
292err:
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
304int 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;
375err:
376	if (ctx   != NULL)
377		BN_CTX_free(ctx);
378	if (point != NULL)
379		EC_POINT_free(point);
380	return(ok);
381	}
382
383int 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
459const EC_GROUP *EC_KEY_get0_group(const EC_KEY *key)
460	{
461	return key->group;
462	}
463
464int 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
472const BIGNUM *EC_KEY_get0_private_key(const EC_KEY *key)
473	{
474	return key->priv_key;
475	}
476
477int 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
485const EC_POINT *EC_KEY_get0_public_key(const EC_KEY *key)
486	{
487	return key->pub_key;
488	}
489
490int 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
498unsigned int EC_KEY_get_enc_flags(const EC_KEY *key)
499	{
500	return key->enc_flag;
501	}
502
503void EC_KEY_set_enc_flags(EC_KEY *key, unsigned int flags)
504	{
505	key->enc_flag = flags;
506	}
507
508point_conversion_form_t EC_KEY_get_conv_form(const EC_KEY *key)
509	{
510	return key->conv_form;
511	}
512
513void 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
520void *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
532void *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
546void 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
552int 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
559int EC_KEY_get_flags(const EC_KEY *key)
560	{
561	return key->flags;
562	}
563
564void EC_KEY_set_flags(EC_KEY *key, int flags)
565	{
566	key->flags |= flags;
567	}
568
569void EC_KEY_clear_flags(EC_KEY *key, int flags)
570	{
571	key->flags &= ~flags;
572	}
573