• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 /* Originally written by Bodo Moeller for the OpenSSL project.
2  * ====================================================================
3  * Copyright (c) 1998-2005 The OpenSSL Project.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  *
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  *
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in
14  *    the documentation and/or other materials provided with the
15  *    distribution.
16  *
17  * 3. All advertising materials mentioning features or use of this
18  *    software must display the following acknowledgment:
19  *    "This product includes software developed by the OpenSSL Project
20  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
21  *
22  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
23  *    endorse or promote products derived from this software without
24  *    prior written permission. For written permission, please contact
25  *    openssl-core@openssl.org.
26  *
27  * 5. Products derived from this software may not be called "OpenSSL"
28  *    nor may "OpenSSL" appear in their names without prior written
29  *    permission of the OpenSSL Project.
30  *
31  * 6. Redistributions of any form whatsoever must retain the following
32  *    acknowledgment:
33  *    "This product includes software developed by the OpenSSL Project
34  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
35  *
36  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
37  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
38  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
39  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
40  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
41  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
42  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
43  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
44  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
45  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
46  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
47  * OF THE POSSIBILITY OF SUCH DAMAGE.
48  * ====================================================================
49  *
50  * This product includes cryptographic software written by Eric Young
51  * (eay@cryptsoft.com).  This product includes software written by Tim
52  * Hudson (tjh@cryptsoft.com).
53  *
54  */
55 /* ====================================================================
56  * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
57  *
58  * Portions of the attached software ("Contribution") are developed by
59  * SUN MICROSYSTEMS, INC., and are contributed to the OpenSSL project.
60  *
61  * The Contribution is licensed pursuant to the OpenSSL open source
62  * license provided above.
63  *
64  * The elliptic curve binary polynomial software is originally written by
65  * Sheueling Chang Shantz and Douglas Stebila of Sun Microsystems
66  * Laboratories. */
67 
68 #include <openssl/ec_key.h>
69 
70 #include <string.h>
71 
72 #include <openssl/ec.h>
73 #include <openssl/ecdsa.h>
74 #include <openssl/engine.h>
75 #include <openssl/err.h>
76 #include <openssl/ex_data.h>
77 #include <openssl/mem.h>
78 #include <openssl/thread.h>
79 
80 #include "internal.h"
81 #include "../delocate.h"
82 #include "../../internal.h"
83 
84 
85 DEFINE_STATIC_EX_DATA_CLASS(g_ec_ex_data_class);
86 
EC_KEY_new(void)87 EC_KEY *EC_KEY_new(void) { return EC_KEY_new_method(NULL); }
88 
EC_KEY_new_method(const ENGINE * engine)89 EC_KEY *EC_KEY_new_method(const ENGINE *engine) {
90   EC_KEY *ret = OPENSSL_malloc(sizeof(EC_KEY));
91   if (ret == NULL) {
92     OPENSSL_PUT_ERROR(EC, ERR_R_MALLOC_FAILURE);
93     return NULL;
94   }
95 
96   OPENSSL_memset(ret, 0, sizeof(EC_KEY));
97 
98   if (engine) {
99     ret->ecdsa_meth = ENGINE_get_ECDSA_method(engine);
100   }
101   if (ret->ecdsa_meth) {
102     METHOD_ref(ret->ecdsa_meth);
103   }
104 
105   ret->conv_form = POINT_CONVERSION_UNCOMPRESSED;
106   ret->references = 1;
107 
108   CRYPTO_new_ex_data(&ret->ex_data);
109 
110   if (ret->ecdsa_meth && ret->ecdsa_meth->init && !ret->ecdsa_meth->init(ret)) {
111     CRYPTO_free_ex_data(g_ec_ex_data_class_bss_get(), ret, &ret->ex_data);
112     if (ret->ecdsa_meth) {
113       METHOD_unref(ret->ecdsa_meth);
114     }
115     OPENSSL_free(ret);
116     return NULL;
117   }
118 
119   return ret;
120 }
121 
EC_KEY_new_by_curve_name(int nid)122 EC_KEY *EC_KEY_new_by_curve_name(int nid) {
123   EC_KEY *ret = EC_KEY_new();
124   if (ret == NULL) {
125     OPENSSL_PUT_ERROR(EC, ERR_R_MALLOC_FAILURE);
126     return NULL;
127   }
128   ret->group = EC_GROUP_new_by_curve_name(nid);
129   if (ret->group == NULL) {
130     EC_KEY_free(ret);
131     return NULL;
132   }
133   return ret;
134 }
135 
EC_KEY_free(EC_KEY * r)136 void EC_KEY_free(EC_KEY *r) {
137   if (r == NULL) {
138     return;
139   }
140 
141   if (!CRYPTO_refcount_dec_and_test_zero(&r->references)) {
142     return;
143   }
144 
145   if (r->ecdsa_meth) {
146     if (r->ecdsa_meth->finish) {
147       r->ecdsa_meth->finish(r);
148     }
149     METHOD_unref(r->ecdsa_meth);
150   }
151 
152   EC_GROUP_free(r->group);
153   EC_POINT_free(r->pub_key);
154   BN_clear_free(r->priv_key);
155   BN_free(r->fixed_k);
156 
157   CRYPTO_free_ex_data(g_ec_ex_data_class_bss_get(), r, &r->ex_data);
158 
159   OPENSSL_cleanse((void *)r, sizeof(EC_KEY));
160   OPENSSL_free(r);
161 }
162 
EC_KEY_copy(EC_KEY * dest,const EC_KEY * src)163 EC_KEY *EC_KEY_copy(EC_KEY *dest, const EC_KEY *src) {
164   if (dest == NULL || src == NULL) {
165     OPENSSL_PUT_ERROR(EC, ERR_R_PASSED_NULL_PARAMETER);
166     return NULL;
167   }
168   /* Copy the parameters. */
169   if (src->group) {
170     /* TODO(fork): duplicating the group seems wasteful. */
171     EC_GROUP_free(dest->group);
172     dest->group = EC_GROUP_dup(src->group);
173     if (dest->group == NULL) {
174       return NULL;
175     }
176   }
177 
178   /* Copy the public key. */
179   if (src->pub_key && src->group) {
180     EC_POINT_free(dest->pub_key);
181     dest->pub_key = EC_POINT_dup(src->pub_key, src->group);
182     if (dest->pub_key == NULL) {
183       return NULL;
184     }
185   }
186 
187   /* copy the private key */
188   if (src->priv_key) {
189     if (dest->priv_key == NULL) {
190       dest->priv_key = BN_new();
191       if (dest->priv_key == NULL) {
192         return NULL;
193       }
194     }
195     if (!BN_copy(dest->priv_key, src->priv_key)) {
196       return NULL;
197     }
198   }
199   /* copy method/extra data */
200   if (src->ecdsa_meth) {
201       METHOD_unref(dest->ecdsa_meth);
202       dest->ecdsa_meth = src->ecdsa_meth;
203       METHOD_ref(dest->ecdsa_meth);
204   }
205 
206   /* copy the rest */
207   dest->enc_flag = src->enc_flag;
208   dest->conv_form = src->conv_form;
209 
210   return dest;
211 }
212 
EC_KEY_dup(const EC_KEY * ec_key)213 EC_KEY *EC_KEY_dup(const EC_KEY *ec_key) {
214   EC_KEY *ret = EC_KEY_new();
215   if (ret == NULL) {
216     return NULL;
217   }
218   if (EC_KEY_copy(ret, ec_key) == NULL) {
219     EC_KEY_free(ret);
220     return NULL;
221   }
222   return ret;
223 }
224 
EC_KEY_up_ref(EC_KEY * r)225 int EC_KEY_up_ref(EC_KEY *r) {
226   CRYPTO_refcount_inc(&r->references);
227   return 1;
228 }
229 
EC_KEY_is_opaque(const EC_KEY * key)230 int EC_KEY_is_opaque(const EC_KEY *key) {
231   return key->ecdsa_meth && (key->ecdsa_meth->flags & ECDSA_FLAG_OPAQUE);
232 }
233 
EC_KEY_get0_group(const EC_KEY * key)234 const EC_GROUP *EC_KEY_get0_group(const EC_KEY *key) { return key->group; }
235 
EC_KEY_set_group(EC_KEY * key,const EC_GROUP * group)236 int EC_KEY_set_group(EC_KEY *key, const EC_GROUP *group) {
237   EC_GROUP_free(key->group);
238   /* TODO(fork): duplicating the group seems wasteful but see
239    * |EC_KEY_set_conv_form|. */
240   key->group = EC_GROUP_dup(group);
241   if (key->group == NULL) {
242     return 0;
243   }
244   /* XXX: |BN_cmp| is not constant time. */
245   if (key->priv_key != NULL &&
246       BN_cmp(key->priv_key, EC_GROUP_get0_order(group)) >= 0) {
247     return 0;
248   }
249   return 1;
250 }
251 
EC_KEY_get0_private_key(const EC_KEY * key)252 const BIGNUM *EC_KEY_get0_private_key(const EC_KEY *key) {
253   return key->priv_key;
254 }
255 
EC_KEY_set_private_key(EC_KEY * key,const BIGNUM * priv_key)256 int EC_KEY_set_private_key(EC_KEY *key, const BIGNUM *priv_key) {
257   /* XXX: |BN_cmp| is not constant time. */
258   if (key->group != NULL &&
259       BN_cmp(priv_key, EC_GROUP_get0_order(key->group)) >= 0) {
260     OPENSSL_PUT_ERROR(EC, EC_R_WRONG_ORDER);
261     return 0;
262   }
263   BN_clear_free(key->priv_key);
264   key->priv_key = BN_dup(priv_key);
265   return (key->priv_key == NULL) ? 0 : 1;
266 }
267 
EC_KEY_get0_public_key(const EC_KEY * key)268 const EC_POINT *EC_KEY_get0_public_key(const EC_KEY *key) {
269   return key->pub_key;
270 }
271 
EC_KEY_set_public_key(EC_KEY * key,const EC_POINT * pub_key)272 int EC_KEY_set_public_key(EC_KEY *key, const EC_POINT *pub_key) {
273   EC_POINT_free(key->pub_key);
274   key->pub_key = EC_POINT_dup(pub_key, key->group);
275   return (key->pub_key == NULL) ? 0 : 1;
276 }
277 
EC_KEY_get_enc_flags(const EC_KEY * key)278 unsigned int EC_KEY_get_enc_flags(const EC_KEY *key) { return key->enc_flag; }
279 
EC_KEY_set_enc_flags(EC_KEY * key,unsigned int flags)280 void EC_KEY_set_enc_flags(EC_KEY *key, unsigned int flags) {
281   key->enc_flag = flags;
282 }
283 
EC_KEY_get_conv_form(const EC_KEY * key)284 point_conversion_form_t EC_KEY_get_conv_form(const EC_KEY *key) {
285   return key->conv_form;
286 }
287 
EC_KEY_set_conv_form(EC_KEY * key,point_conversion_form_t cform)288 void EC_KEY_set_conv_form(EC_KEY *key, point_conversion_form_t cform) {
289   key->conv_form = cform;
290 }
291 
EC_KEY_check_key(const EC_KEY * eckey)292 int EC_KEY_check_key(const EC_KEY *eckey) {
293   int ok = 0;
294   BN_CTX *ctx = NULL;
295   EC_POINT *point = NULL;
296 
297   if (!eckey || !eckey->group || !eckey->pub_key) {
298     OPENSSL_PUT_ERROR(EC, ERR_R_PASSED_NULL_PARAMETER);
299     return 0;
300   }
301 
302   if (EC_POINT_is_at_infinity(eckey->group, eckey->pub_key)) {
303     OPENSSL_PUT_ERROR(EC, EC_R_POINT_AT_INFINITY);
304     goto err;
305   }
306 
307   ctx = BN_CTX_new();
308 
309   if (ctx == NULL) {
310     goto err;
311   }
312 
313   /* testing whether the pub_key is on the elliptic curve */
314   if (!EC_POINT_is_on_curve(eckey->group, eckey->pub_key, ctx)) {
315     OPENSSL_PUT_ERROR(EC, EC_R_POINT_IS_NOT_ON_CURVE);
316     goto err;
317   }
318   /* in case the priv_key is present :
319    * check if generator * priv_key == pub_key
320    */
321   if (eckey->priv_key) {
322     /* XXX: |BN_cmp| is not constant time. */
323     if (BN_cmp(eckey->priv_key, EC_GROUP_get0_order(eckey->group)) >= 0) {
324       OPENSSL_PUT_ERROR(EC, EC_R_WRONG_ORDER);
325       goto err;
326     }
327     point = EC_POINT_new(eckey->group);
328     if (point == NULL ||
329         !EC_POINT_mul(eckey->group, point, eckey->priv_key, NULL, NULL, ctx)) {
330       OPENSSL_PUT_ERROR(EC, ERR_R_EC_LIB);
331       goto err;
332     }
333     if (EC_POINT_cmp(eckey->group, point, eckey->pub_key, ctx) != 0) {
334       OPENSSL_PUT_ERROR(EC, EC_R_INVALID_PRIVATE_KEY);
335       goto err;
336     }
337   }
338   ok = 1;
339 
340 err:
341   BN_CTX_free(ctx);
342   EC_POINT_free(point);
343   return ok;
344 }
345 
EC_KEY_check_fips(const EC_KEY * key)346 int EC_KEY_check_fips(const EC_KEY *key) {
347   if (EC_KEY_is_opaque(key)) {
348     /* Opaque keys can't be checked. */
349     OPENSSL_PUT_ERROR(EC, EC_R_PUBLIC_KEY_VALIDATION_FAILED);
350     return 0;
351   }
352 
353   if (!EC_KEY_check_key(key)) {
354     return 0;
355   }
356 
357   if (key->priv_key) {
358     uint8_t data[16] = {0};
359     ECDSA_SIG *sig = ECDSA_do_sign(data, sizeof(data), key);
360 #if defined(BORINGSSL_FIPS_BREAK_ECDSA_PWCT)
361     data[0] = ~data[0];
362 #endif
363     int ok = sig != NULL &&
364              ECDSA_do_verify(data, sizeof(data), sig, key);
365     ECDSA_SIG_free(sig);
366     if (!ok) {
367       OPENSSL_PUT_ERROR(EC, EC_R_PUBLIC_KEY_VALIDATION_FAILED);
368       return 0;
369     }
370   }
371 
372   return 1;
373 }
374 
EC_KEY_set_public_key_affine_coordinates(EC_KEY * key,BIGNUM * x,BIGNUM * y)375 int EC_KEY_set_public_key_affine_coordinates(EC_KEY *key, BIGNUM *x,
376                                              BIGNUM *y) {
377   BN_CTX *ctx = NULL;
378   BIGNUM *tx, *ty;
379   EC_POINT *point = NULL;
380   int ok = 0;
381 
382   if (!key || !key->group || !x || !y) {
383     OPENSSL_PUT_ERROR(EC, ERR_R_PASSED_NULL_PARAMETER);
384     return 0;
385   }
386   ctx = BN_CTX_new();
387 
388   if (ctx == NULL) {
389     return 0;
390   }
391 
392   BN_CTX_start(ctx);
393   point = EC_POINT_new(key->group);
394 
395   if (point == NULL) {
396     goto err;
397   }
398 
399   tx = BN_CTX_get(ctx);
400   ty = BN_CTX_get(ctx);
401   if (tx == NULL ||
402       ty == NULL) {
403     goto err;
404   }
405 
406   if (!EC_POINT_set_affine_coordinates_GFp(key->group, point, x, y, ctx) ||
407       !EC_POINT_get_affine_coordinates_GFp(key->group, point, tx, ty, ctx)) {
408     goto err;
409   }
410 
411   /* Check if retrieved coordinates match originals: if not values
412    * are out of range. */
413   if (BN_cmp(x, tx) || BN_cmp(y, ty)) {
414     OPENSSL_PUT_ERROR(EC, EC_R_COORDINATES_OUT_OF_RANGE);
415     goto err;
416   }
417 
418   if (!EC_KEY_set_public_key(key, point)) {
419     goto err;
420   }
421 
422   if (EC_KEY_check_key(key) == 0) {
423     goto err;
424   }
425 
426   ok = 1;
427 
428 err:
429   BN_CTX_end(ctx);
430   BN_CTX_free(ctx);
431   EC_POINT_free(point);
432   return ok;
433 }
434 
EC_KEY_generate_key(EC_KEY * eckey)435 int EC_KEY_generate_key(EC_KEY *eckey) {
436   int ok = 0;
437   BIGNUM *priv_key = NULL;
438   EC_POINT *pub_key = NULL;
439 
440   if (!eckey || !eckey->group) {
441     OPENSSL_PUT_ERROR(EC, ERR_R_PASSED_NULL_PARAMETER);
442     return 0;
443   }
444 
445   if (eckey->priv_key == NULL) {
446     priv_key = BN_new();
447     if (priv_key == NULL) {
448       goto err;
449     }
450   } else {
451     priv_key = eckey->priv_key;
452   }
453 
454   const BIGNUM *order = EC_GROUP_get0_order(eckey->group);
455 
456   /* Check that the size of the group order is FIPS compliant (FIPS 186-4
457    * B.4.2). */
458   if (BN_num_bits(order) < 160) {
459     OPENSSL_PUT_ERROR(EC, EC_R_INVALID_GROUP_ORDER);
460     goto err;
461   }
462 
463   /* Generate the private key by testing candidates (FIPS 186-4 B.4.2). */
464   if (!BN_rand_range_ex(priv_key, 1, order)) {
465     goto err;
466   }
467 
468   if (eckey->pub_key == NULL) {
469     pub_key = EC_POINT_new(eckey->group);
470     if (pub_key == NULL) {
471       goto err;
472     }
473   } else {
474     pub_key = eckey->pub_key;
475   }
476 
477   if (!EC_POINT_mul(eckey->group, pub_key, priv_key, NULL, NULL, NULL)) {
478     goto err;
479   }
480 
481   eckey->priv_key = priv_key;
482   eckey->pub_key = pub_key;
483 
484   ok = 1;
485 
486 err:
487   if (eckey->pub_key == NULL) {
488     EC_POINT_free(pub_key);
489   }
490   if (eckey->priv_key == NULL) {
491     BN_free(priv_key);
492   }
493   return ok;
494 }
495 
EC_KEY_generate_key_fips(EC_KEY * eckey)496 int EC_KEY_generate_key_fips(EC_KEY *eckey) {
497   return EC_KEY_generate_key(eckey) && EC_KEY_check_fips(eckey);
498 }
499 
EC_KEY_get_ex_new_index(long argl,void * argp,CRYPTO_EX_unused * unused,CRYPTO_EX_dup * dup_unused,CRYPTO_EX_free * free_func)500 int EC_KEY_get_ex_new_index(long argl, void *argp, CRYPTO_EX_unused *unused,
501                             CRYPTO_EX_dup *dup_unused,
502                             CRYPTO_EX_free *free_func) {
503   int index;
504   if (!CRYPTO_get_ex_new_index(g_ec_ex_data_class_bss_get(), &index, argl, argp,
505                                free_func)) {
506     return -1;
507   }
508   return index;
509 }
510 
EC_KEY_set_ex_data(EC_KEY * d,int idx,void * arg)511 int EC_KEY_set_ex_data(EC_KEY *d, int idx, void *arg) {
512   return CRYPTO_set_ex_data(&d->ex_data, idx, arg);
513 }
514 
EC_KEY_get_ex_data(const EC_KEY * d,int idx)515 void *EC_KEY_get_ex_data(const EC_KEY *d, int idx) {
516   return CRYPTO_get_ex_data(&d->ex_data, idx);
517 }
518 
EC_KEY_set_asn1_flag(EC_KEY * key,int flag)519 void EC_KEY_set_asn1_flag(EC_KEY *key, int flag) {}
520