ec_key.c revision 306195 
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        ECerr(EC_F_EC_KEY_NEW, ERR_R_MALLOC_FAILURE);
78        return (NULL);
79    }
80
81    ret->version = 1;
82    ret->flags = 0;
83    ret->group = NULL;
84    ret->pub_key = NULL;
85    ret->priv_key = NULL;
86    ret->enc_flag = 0;
87    ret->conv_form = POINT_CONVERSION_UNCOMPRESSED;
88    ret->references = 1;
89    ret->method_data = NULL;
90    return (ret);
91}
92
93EC_KEY *EC_KEY_new_by_curve_name(int nid)
94{
95    EC_KEY *ret = EC_KEY_new();
96    if (ret == NULL)
97        return NULL;
98    ret->group = EC_GROUP_new_by_curve_name(nid);
99    if (ret->group == NULL) {
100        EC_KEY_free(ret);
101        return NULL;
102    }
103    return ret;
104}
105
106void EC_KEY_free(EC_KEY *r)
107{
108    int i;
109
110    if (r == NULL)
111        return;
112
113    i = CRYPTO_add(&r->references, -1, CRYPTO_LOCK_EC);
114#ifdef REF_PRINT
115    REF_PRINT("EC_KEY", r);
116#endif
117    if (i > 0)
118        return;
119#ifdef REF_CHECK
120    if (i < 0) {
121        fprintf(stderr, "EC_KEY_free, bad reference count\n");
122        abort();
123    }
124#endif
125
126    if (r->group != NULL)
127        EC_GROUP_free(r->group);
128    if (r->pub_key != NULL)
129        EC_POINT_free(r->pub_key);
130    if (r->priv_key != NULL)
131        BN_clear_free(r->priv_key);
132
133    EC_EX_DATA_free_all_data(&r->method_data);
134
135    OPENSSL_cleanse((void *)r, sizeof(EC_KEY));
136
137    OPENSSL_free(r);
138}
139
140EC_KEY *EC_KEY_copy(EC_KEY *dest, const EC_KEY *src)
141{
142    EC_EXTRA_DATA *d;
143
144    if (dest == NULL || src == NULL) {
145        ECerr(EC_F_EC_KEY_COPY, ERR_R_PASSED_NULL_PARAMETER);
146        return NULL;
147    }
148    /* copy the parameters */
149    if (src->group) {
150        const EC_METHOD *meth = EC_GROUP_method_of(src->group);
151        /* clear the old group */
152        if (dest->group)
153            EC_GROUP_free(dest->group);
154        dest->group = EC_GROUP_new(meth);
155        if (dest->group == NULL)
156            return NULL;
157        if (!EC_GROUP_copy(dest->group, src->group))
158            return NULL;
159    }
160    /*  copy the public key */
161    if (src->pub_key && src->group) {
162        if (dest->pub_key)
163            EC_POINT_free(dest->pub_key);
164        dest->pub_key = EC_POINT_new(src->group);
165        if (dest->pub_key == NULL)
166            return NULL;
167        if (!EC_POINT_copy(dest->pub_key, src->pub_key))
168            return NULL;
169    }
170    /* copy the private key */
171    if (src->priv_key) {
172        if (dest->priv_key == NULL) {
173            dest->priv_key = BN_new();
174            if (dest->priv_key == NULL)
175                return NULL;
176        }
177        if (!BN_copy(dest->priv_key, src->priv_key))
178            return NULL;
179    }
180    /* copy method/extra data */
181    EC_EX_DATA_free_all_data(&dest->method_data);
182
183    for (d = src->method_data; d != NULL; d = d->next) {
184        void *t = d->dup_func(d->data);
185
186        if (t == NULL)
187            return 0;
188        if (!EC_EX_DATA_set_data
189            (&dest->method_data, t, d->dup_func, d->free_func,
190             d->clear_free_func))
191            return 0;
192    }
193
194    /* copy the rest */
195    dest->enc_flag = src->enc_flag;
196    dest->conv_form = src->conv_form;
197    dest->version = src->version;
198    dest->flags = src->flags;
199
200    return dest;
201}
202
203EC_KEY *EC_KEY_dup(const EC_KEY *ec_key)
204{
205    EC_KEY *ret = EC_KEY_new();
206    if (ret == NULL)
207        return NULL;
208    if (EC_KEY_copy(ret, ec_key) == NULL) {
209        EC_KEY_free(ret);
210        return NULL;
211    }
212    return ret;
213}
214
215int EC_KEY_up_ref(EC_KEY *r)
216{
217    int i = CRYPTO_add(&r->references, 1, CRYPTO_LOCK_EC);
218#ifdef REF_PRINT
219    REF_PRINT("EC_KEY", r);
220#endif
221#ifdef REF_CHECK
222    if (i < 2) {
223        fprintf(stderr, "EC_KEY_up, bad reference count\n");
224        abort();
225    }
226#endif
227    return ((i > 1) ? 1 : 0);
228}
229
230int EC_KEY_generate_key(EC_KEY *eckey)
231{
232    int ok = 0;
233    BN_CTX *ctx = NULL;
234    BIGNUM *priv_key = NULL, *order = NULL;
235    EC_POINT *pub_key = NULL;
236
237#ifdef OPENSSL_FIPS
238    if (FIPS_mode())
239        return FIPS_ec_key_generate_key(eckey);
240#endif
241
242    if (!eckey || !eckey->group) {
243        ECerr(EC_F_EC_KEY_GENERATE_KEY, ERR_R_PASSED_NULL_PARAMETER);
244        return 0;
245    }
246
247    if ((order = BN_new()) == NULL)
248        goto err;
249    if ((ctx = BN_CTX_new()) == NULL)
250        goto err;
251
252    if (eckey->priv_key == NULL) {
253        priv_key = BN_new();
254        if (priv_key == NULL)
255            goto err;
256    } else
257        priv_key = eckey->priv_key;
258
259    if (!EC_GROUP_get_order(eckey->group, order, ctx))
260        goto err;
261
262    do
263        if (!BN_rand_range(priv_key, order))
264            goto err;
265    while (BN_is_zero(priv_key)) ;
266
267    if (eckey->pub_key == NULL) {
268        pub_key = EC_POINT_new(eckey->group);
269        if (pub_key == NULL)
270            goto err;
271    } else
272        pub_key = eckey->pub_key;
273
274    if (!EC_POINT_mul(eckey->group, pub_key, priv_key, NULL, NULL, ctx))
275        goto err;
276
277    eckey->priv_key = priv_key;
278    eckey->pub_key = pub_key;
279
280    ok = 1;
281
282 err:
283    if (order)
284        BN_free(order);
285    if (pub_key != NULL && eckey->pub_key == NULL)
286        EC_POINT_free(pub_key);
287    if (priv_key != NULL && eckey->priv_key == NULL)
288        BN_free(priv_key);
289    if (ctx != NULL)
290        BN_CTX_free(ctx);
291    return (ok);
292}
293
294int EC_KEY_check_key(const EC_KEY *eckey)
295{
296    int ok = 0;
297    BN_CTX *ctx = NULL;
298    const BIGNUM *order = NULL;
299    EC_POINT *point = NULL;
300
301    if (!eckey || !eckey->group || !eckey->pub_key) {
302        ECerr(EC_F_EC_KEY_CHECK_KEY, ERR_R_PASSED_NULL_PARAMETER);
303        return 0;
304    }
305
306    if (EC_POINT_is_at_infinity(eckey->group, eckey->pub_key)) {
307        ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_POINT_AT_INFINITY);
308        goto err;
309    }
310
311    if ((ctx = BN_CTX_new()) == NULL)
312        goto err;
313    if ((point = EC_POINT_new(eckey->group)) == NULL)
314        goto err;
315
316    /* testing whether the pub_key is on the elliptic curve */
317    if (EC_POINT_is_on_curve(eckey->group, eckey->pub_key, ctx) <= 0) {
318        ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_POINT_IS_NOT_ON_CURVE);
319        goto err;
320    }
321    /* testing whether pub_key * order is the point at infinity */
322    order = &eckey->group->order;
323    if (BN_is_zero(order)) {
324        ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_INVALID_GROUP_ORDER);
325        goto err;
326    }
327    if (!EC_POINT_mul(eckey->group, point, NULL, eckey->pub_key, order, ctx)) {
328        ECerr(EC_F_EC_KEY_CHECK_KEY, ERR_R_EC_LIB);
329        goto err;
330    }
331    if (!EC_POINT_is_at_infinity(eckey->group, point)) {
332        ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_WRONG_ORDER);
333        goto err;
334    }
335    /*
336     * in case the priv_key is present : check if generator * priv_key ==
337     * pub_key
338     */
339    if (eckey->priv_key) {
340        if (BN_cmp(eckey->priv_key, order) >= 0) {
341            ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_WRONG_ORDER);
342            goto err;
343        }
344        if (!EC_POINT_mul(eckey->group, point, eckey->priv_key,
345                          NULL, NULL, ctx)) {
346            ECerr(EC_F_EC_KEY_CHECK_KEY, ERR_R_EC_LIB);
347            goto err;
348        }
349        if (EC_POINT_cmp(eckey->group, point, eckey->pub_key, ctx) != 0) {
350            ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_INVALID_PRIVATE_KEY);
351            goto err;
352        }
353    }
354    ok = 1;
355 err:
356    if (ctx != NULL)
357        BN_CTX_free(ctx);
358    if (point != NULL)
359        EC_POINT_free(point);
360    return (ok);
361}
362
363int EC_KEY_set_public_key_affine_coordinates(EC_KEY *key, BIGNUM *x,
364                                             BIGNUM *y)
365{
366    BN_CTX *ctx = NULL;
367    BIGNUM *tx, *ty;
368    EC_POINT *point = NULL;
369    int ok = 0;
370#ifndef OPENSSL_NO_EC2M
371    int tmp_nid, is_char_two = 0;
372#endif
373
374    if (!key || !key->group || !x || !y) {
375        ECerr(EC_F_EC_KEY_SET_PUBLIC_KEY_AFFINE_COORDINATES,
376              ERR_R_PASSED_NULL_PARAMETER);
377        return 0;
378    }
379    ctx = BN_CTX_new();
380    if (ctx == NULL)
381        return 0;
382    BN_CTX_start(ctx);
383    point = EC_POINT_new(key->group);
384
385    if (!point)
386        goto err;
387
388    tx = BN_CTX_get(ctx);
389    ty = BN_CTX_get(ctx);
390    if (ty == NULL)
391        goto err;
392
393#ifndef OPENSSL_NO_EC2M
394    tmp_nid = EC_METHOD_get_field_type(EC_GROUP_method_of(key->group));
395
396    if (tmp_nid == NID_X9_62_characteristic_two_field)
397        is_char_two = 1;
398
399    if (is_char_two) {
400        if (!EC_POINT_set_affine_coordinates_GF2m(key->group, point,
401                                                  x, y, ctx))
402            goto err;
403        if (!EC_POINT_get_affine_coordinates_GF2m(key->group, point,
404                                                  tx, ty, ctx))
405            goto err;
406    } else
407#endif
408    {
409        if (!EC_POINT_set_affine_coordinates_GFp(key->group, point,
410                                                 x, y, ctx))
411            goto err;
412        if (!EC_POINT_get_affine_coordinates_GFp(key->group, point,
413                                                 tx, ty, ctx))
414            goto err;
415    }
416    /*
417     * Check if retrieved coordinates match originals: if not values are out
418     * of range.
419     */
420    if (BN_cmp(x, tx) || BN_cmp(y, ty)) {
421        ECerr(EC_F_EC_KEY_SET_PUBLIC_KEY_AFFINE_COORDINATES,
422              EC_R_COORDINATES_OUT_OF_RANGE);
423        goto err;
424    }
425
426    if (!EC_KEY_set_public_key(key, point))
427        goto err;
428
429    if (EC_KEY_check_key(key) == 0)
430        goto err;
431
432    ok = 1;
433
434 err:
435    BN_CTX_end(ctx);
436    BN_CTX_free(ctx);
437    EC_POINT_free(point);
438    return ok;
439
440}
441
442const EC_GROUP *EC_KEY_get0_group(const EC_KEY *key)
443{
444    return key->group;
445}
446
447int EC_KEY_set_group(EC_KEY *key, const EC_GROUP *group)
448{
449    if (key->group != NULL)
450        EC_GROUP_free(key->group);
451    key->group = EC_GROUP_dup(group);
452    return (key->group == NULL) ? 0 : 1;
453}
454
455const BIGNUM *EC_KEY_get0_private_key(const EC_KEY *key)
456{
457    return key->priv_key;
458}
459
460int EC_KEY_set_private_key(EC_KEY *key, const BIGNUM *priv_key)
461{
462    if (key->priv_key)
463        BN_clear_free(key->priv_key);
464    key->priv_key = BN_dup(priv_key);
465    return (key->priv_key == NULL) ? 0 : 1;
466}
467
468const EC_POINT *EC_KEY_get0_public_key(const EC_KEY *key)
469{
470    return key->pub_key;
471}
472
473int EC_KEY_set_public_key(EC_KEY *key, const EC_POINT *pub_key)
474{
475    if (key->pub_key != NULL)
476        EC_POINT_free(key->pub_key);
477    key->pub_key = EC_POINT_dup(pub_key, key->group);
478    return (key->pub_key == NULL) ? 0 : 1;
479}
480
481unsigned int EC_KEY_get_enc_flags(const EC_KEY *key)
482{
483    return key->enc_flag;
484}
485
486void EC_KEY_set_enc_flags(EC_KEY *key, unsigned int flags)
487{
488    key->enc_flag = flags;
489}
490
491point_conversion_form_t EC_KEY_get_conv_form(const EC_KEY *key)
492{
493    return key->conv_form;
494}
495
496void EC_KEY_set_conv_form(EC_KEY *key, point_conversion_form_t cform)
497{
498    key->conv_form = cform;
499    if (key->group != NULL)
500        EC_GROUP_set_point_conversion_form(key->group, cform);
501}
502
503void *EC_KEY_get_key_method_data(EC_KEY *key,
504                                 void *(*dup_func) (void *),
505                                 void (*free_func) (void *),
506                                 void (*clear_free_func) (void *))
507{
508    void *ret;
509
510    CRYPTO_r_lock(CRYPTO_LOCK_EC);
511    ret =
512        EC_EX_DATA_get_data(key->method_data, dup_func, free_func,
513                            clear_free_func);
514    CRYPTO_r_unlock(CRYPTO_LOCK_EC);
515
516    return ret;
517}
518
519void *EC_KEY_insert_key_method_data(EC_KEY *key, void *data,
520                                    void *(*dup_func) (void *),
521                                    void (*free_func) (void *),
522                                    void (*clear_free_func) (void *))
523{
524    EC_EXTRA_DATA *ex_data;
525
526    CRYPTO_w_lock(CRYPTO_LOCK_EC);
527    ex_data =
528        EC_EX_DATA_get_data(key->method_data, dup_func, free_func,
529                            clear_free_func);
530    if (ex_data == NULL)
531        EC_EX_DATA_set_data(&key->method_data, data, dup_func, free_func,
532                            clear_free_func);
533    CRYPTO_w_unlock(CRYPTO_LOCK_EC);
534
535    return ex_data;
536}
537
538void EC_KEY_set_asn1_flag(EC_KEY *key, int flag)
539{
540    if (key->group != NULL)
541        EC_GROUP_set_asn1_flag(key->group, flag);
542}
543
544int EC_KEY_precompute_mult(EC_KEY *key, BN_CTX *ctx)
545{
546    if (key->group == NULL)
547        return 0;
548    return EC_GROUP_precompute_mult(key->group, ctx);
549}
550
551int EC_KEY_get_flags(const EC_KEY *key)
552{
553    return key->flags;
554}
555
556void EC_KEY_set_flags(EC_KEY *key, int flags)
557{
558    key->flags |= flags;
559}
560
561void EC_KEY_clear_flags(EC_KEY *key, int flags)
562{
563    key->flags &= ~flags;
564}
565