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
DEFINE_STATIC_EX_DATA_CLASS(g_ec_ex_data_class)85 DEFINE_STATIC_EX_DATA_CLASS(g_ec_ex_data_class)
86
87 static EC_WRAPPED_SCALAR *ec_wrapped_scalar_new(const EC_GROUP *group) {
88 EC_WRAPPED_SCALAR *wrapped = OPENSSL_malloc(sizeof(EC_WRAPPED_SCALAR));
89 if (wrapped == NULL) {
90 OPENSSL_PUT_ERROR(EC, ERR_R_MALLOC_FAILURE);
91 return NULL;
92 }
93
94 OPENSSL_memset(wrapped, 0, sizeof(EC_WRAPPED_SCALAR));
95 wrapped->bignum.d = wrapped->scalar.words;
96 wrapped->bignum.width = group->order.width;
97 wrapped->bignum.dmax = group->order.width;
98 wrapped->bignum.flags = BN_FLG_STATIC_DATA;
99 return wrapped;
100 }
101
ec_wrapped_scalar_free(EC_WRAPPED_SCALAR * scalar)102 static void ec_wrapped_scalar_free(EC_WRAPPED_SCALAR *scalar) {
103 OPENSSL_free(scalar);
104 }
105
EC_KEY_new(void)106 EC_KEY *EC_KEY_new(void) { return EC_KEY_new_method(NULL); }
107
EC_KEY_new_method(const ENGINE * engine)108 EC_KEY *EC_KEY_new_method(const ENGINE *engine) {
109 EC_KEY *ret = OPENSSL_malloc(sizeof(EC_KEY));
110 if (ret == NULL) {
111 OPENSSL_PUT_ERROR(EC, ERR_R_MALLOC_FAILURE);
112 return NULL;
113 }
114
115 OPENSSL_memset(ret, 0, sizeof(EC_KEY));
116
117 if (engine) {
118 ret->ecdsa_meth = ENGINE_get_ECDSA_method(engine);
119 }
120 if (ret->ecdsa_meth) {
121 METHOD_ref(ret->ecdsa_meth);
122 }
123
124 ret->conv_form = POINT_CONVERSION_UNCOMPRESSED;
125 ret->references = 1;
126
127 CRYPTO_new_ex_data(&ret->ex_data);
128
129 if (ret->ecdsa_meth && ret->ecdsa_meth->init && !ret->ecdsa_meth->init(ret)) {
130 CRYPTO_free_ex_data(g_ec_ex_data_class_bss_get(), ret, &ret->ex_data);
131 if (ret->ecdsa_meth) {
132 METHOD_unref(ret->ecdsa_meth);
133 }
134 OPENSSL_free(ret);
135 return NULL;
136 }
137
138 return ret;
139 }
140
EC_KEY_new_by_curve_name(int nid)141 EC_KEY *EC_KEY_new_by_curve_name(int nid) {
142 EC_KEY *ret = EC_KEY_new();
143 if (ret == NULL) {
144 OPENSSL_PUT_ERROR(EC, ERR_R_MALLOC_FAILURE);
145 return NULL;
146 }
147 ret->group = EC_GROUP_new_by_curve_name(nid);
148 if (ret->group == NULL) {
149 EC_KEY_free(ret);
150 return NULL;
151 }
152 return ret;
153 }
154
EC_KEY_free(EC_KEY * r)155 void EC_KEY_free(EC_KEY *r) {
156 if (r == NULL) {
157 return;
158 }
159
160 if (!CRYPTO_refcount_dec_and_test_zero(&r->references)) {
161 return;
162 }
163
164 if (r->ecdsa_meth) {
165 if (r->ecdsa_meth->finish) {
166 r->ecdsa_meth->finish(r);
167 }
168 METHOD_unref(r->ecdsa_meth);
169 }
170
171 EC_GROUP_free(r->group);
172 EC_POINT_free(r->pub_key);
173 ec_wrapped_scalar_free(r->priv_key);
174 BN_free(r->fixed_k);
175
176 CRYPTO_free_ex_data(g_ec_ex_data_class_bss_get(), r, &r->ex_data);
177
178 OPENSSL_free(r);
179 }
180
EC_KEY_dup(const EC_KEY * src)181 EC_KEY *EC_KEY_dup(const EC_KEY *src) {
182 if (src == NULL) {
183 OPENSSL_PUT_ERROR(EC, ERR_R_PASSED_NULL_PARAMETER);
184 return NULL;
185 }
186
187 EC_KEY *ret = EC_KEY_new();
188 if (ret == NULL) {
189 return NULL;
190 }
191
192 if ((src->group != NULL &&
193 !EC_KEY_set_group(ret, src->group)) ||
194 (src->pub_key != NULL &&
195 !EC_KEY_set_public_key(ret, src->pub_key)) ||
196 (src->priv_key != NULL &&
197 !EC_KEY_set_private_key(ret, EC_KEY_get0_private_key(src)))) {
198 EC_KEY_free(ret);
199 return NULL;
200 }
201
202 ret->enc_flag = src->enc_flag;
203 ret->conv_form = src->conv_form;
204 return ret;
205 }
206
EC_KEY_up_ref(EC_KEY * r)207 int EC_KEY_up_ref(EC_KEY *r) {
208 CRYPTO_refcount_inc(&r->references);
209 return 1;
210 }
211
EC_KEY_is_opaque(const EC_KEY * key)212 int EC_KEY_is_opaque(const EC_KEY *key) {
213 return key->ecdsa_meth && (key->ecdsa_meth->flags & ECDSA_FLAG_OPAQUE);
214 }
215
EC_KEY_get0_group(const EC_KEY * key)216 const EC_GROUP *EC_KEY_get0_group(const EC_KEY *key) { return key->group; }
217
EC_KEY_set_group(EC_KEY * key,const EC_GROUP * group)218 int EC_KEY_set_group(EC_KEY *key, const EC_GROUP *group) {
219 // If |key| already has a group, it is an error to switch to another one.
220 if (key->group != NULL) {
221 if (EC_GROUP_cmp(key->group, group, NULL) != 0) {
222 OPENSSL_PUT_ERROR(EC, EC_R_GROUP_MISMATCH);
223 return 0;
224 }
225 return 1;
226 }
227
228 assert(key->priv_key == NULL);
229 assert(key->pub_key == NULL);
230
231 EC_GROUP_free(key->group);
232 key->group = EC_GROUP_dup(group);
233 return key->group != NULL;
234 }
235
EC_KEY_get0_private_key(const EC_KEY * key)236 const BIGNUM *EC_KEY_get0_private_key(const EC_KEY *key) {
237 return key->priv_key != NULL ? &key->priv_key->bignum : NULL;
238 }
239
EC_KEY_set_private_key(EC_KEY * key,const BIGNUM * priv_key)240 int EC_KEY_set_private_key(EC_KEY *key, const BIGNUM *priv_key) {
241 if (key->group == NULL) {
242 OPENSSL_PUT_ERROR(EC, EC_R_MISSING_PARAMETERS);
243 return 0;
244 }
245
246 EC_WRAPPED_SCALAR *scalar = ec_wrapped_scalar_new(key->group);
247 if (scalar == NULL) {
248 return 0;
249 }
250 if (!ec_bignum_to_scalar(key->group, &scalar->scalar, priv_key)) {
251 OPENSSL_PUT_ERROR(EC, EC_R_WRONG_ORDER);
252 ec_wrapped_scalar_free(scalar);
253 return 0;
254 }
255 ec_wrapped_scalar_free(key->priv_key);
256 key->priv_key = scalar;
257 return 1;
258 }
259
EC_KEY_get0_public_key(const EC_KEY * key)260 const EC_POINT *EC_KEY_get0_public_key(const EC_KEY *key) {
261 return key->pub_key;
262 }
263
EC_KEY_set_public_key(EC_KEY * key,const EC_POINT * pub_key)264 int EC_KEY_set_public_key(EC_KEY *key, const EC_POINT *pub_key) {
265 if (key->group == NULL) {
266 OPENSSL_PUT_ERROR(EC, EC_R_MISSING_PARAMETERS);
267 return 0;
268 }
269
270 if (pub_key != NULL && EC_GROUP_cmp(key->group, pub_key->group, NULL) != 0) {
271 OPENSSL_PUT_ERROR(EC, EC_R_GROUP_MISMATCH);
272 return 0;
273 }
274
275 EC_POINT_free(key->pub_key);
276 key->pub_key = EC_POINT_dup(pub_key, key->group);
277 return (key->pub_key == NULL) ? 0 : 1;
278 }
279
EC_KEY_get_enc_flags(const EC_KEY * key)280 unsigned int EC_KEY_get_enc_flags(const EC_KEY *key) { return key->enc_flag; }
281
EC_KEY_set_enc_flags(EC_KEY * key,unsigned int flags)282 void EC_KEY_set_enc_flags(EC_KEY *key, unsigned int flags) {
283 key->enc_flag = flags;
284 }
285
EC_KEY_get_conv_form(const EC_KEY * key)286 point_conversion_form_t EC_KEY_get_conv_form(const EC_KEY *key) {
287 return key->conv_form;
288 }
289
EC_KEY_set_conv_form(EC_KEY * key,point_conversion_form_t cform)290 void EC_KEY_set_conv_form(EC_KEY *key, point_conversion_form_t cform) {
291 key->conv_form = cform;
292 }
293
EC_KEY_check_key(const EC_KEY * eckey)294 int EC_KEY_check_key(const EC_KEY *eckey) {
295 int ok = 0;
296 BN_CTX *ctx = NULL;
297 EC_POINT *point = NULL;
298
299 if (!eckey || !eckey->group || !eckey->pub_key) {
300 OPENSSL_PUT_ERROR(EC, ERR_R_PASSED_NULL_PARAMETER);
301 return 0;
302 }
303
304 if (EC_POINT_is_at_infinity(eckey->group, eckey->pub_key)) {
305 OPENSSL_PUT_ERROR(EC, EC_R_POINT_AT_INFINITY);
306 goto err;
307 }
308
309 ctx = BN_CTX_new();
310
311 if (ctx == NULL) {
312 goto err;
313 }
314
315 // testing whether the pub_key is on the elliptic curve
316 if (!EC_POINT_is_on_curve(eckey->group, eckey->pub_key, ctx)) {
317 OPENSSL_PUT_ERROR(EC, EC_R_POINT_IS_NOT_ON_CURVE);
318 goto err;
319 }
320 // in case the priv_key is present :
321 // check if generator * priv_key == pub_key
322 if (eckey->priv_key != NULL) {
323 point = EC_POINT_new(eckey->group);
324 if (point == NULL ||
325 !ec_point_mul_scalar(eckey->group, &point->raw,
326 &eckey->priv_key->scalar, NULL, NULL)) {
327 OPENSSL_PUT_ERROR(EC, ERR_R_EC_LIB);
328 goto err;
329 }
330 if (EC_POINT_cmp(eckey->group, point, eckey->pub_key, ctx) != 0) {
331 OPENSSL_PUT_ERROR(EC, EC_R_INVALID_PRIVATE_KEY);
332 goto err;
333 }
334 }
335 ok = 1;
336
337 err:
338 BN_CTX_free(ctx);
339 EC_POINT_free(point);
340 return ok;
341 }
342
EC_KEY_check_fips(const EC_KEY * key)343 int EC_KEY_check_fips(const EC_KEY *key) {
344 if (EC_KEY_is_opaque(key)) {
345 // Opaque keys can't be checked.
346 OPENSSL_PUT_ERROR(EC, EC_R_PUBLIC_KEY_VALIDATION_FAILED);
347 return 0;
348 }
349
350 if (!EC_KEY_check_key(key)) {
351 return 0;
352 }
353
354 if (key->priv_key) {
355 uint8_t data[16] = {0};
356 ECDSA_SIG *sig = ECDSA_do_sign(data, sizeof(data), key);
357 #if defined(BORINGSSL_FIPS_BREAK_ECDSA_PWCT)
358 data[0] = ~data[0];
359 #endif
360 int ok = sig != NULL &&
361 ECDSA_do_verify(data, sizeof(data), sig, key);
362 ECDSA_SIG_free(sig);
363 if (!ok) {
364 OPENSSL_PUT_ERROR(EC, EC_R_PUBLIC_KEY_VALIDATION_FAILED);
365 return 0;
366 }
367 }
368
369 return 1;
370 }
371
EC_KEY_set_public_key_affine_coordinates(EC_KEY * key,BIGNUM * x,BIGNUM * y)372 int EC_KEY_set_public_key_affine_coordinates(EC_KEY *key, BIGNUM *x,
373 BIGNUM *y) {
374 EC_POINT *point = NULL;
375 int ok = 0;
376
377 if (!key || !key->group || !x || !y) {
378 OPENSSL_PUT_ERROR(EC, ERR_R_PASSED_NULL_PARAMETER);
379 return 0;
380 }
381
382 point = EC_POINT_new(key->group);
383 if (point == NULL ||
384 !EC_POINT_set_affine_coordinates_GFp(key->group, point, x, y, NULL) ||
385 !EC_KEY_set_public_key(key, point) ||
386 !EC_KEY_check_key(key)) {
387 goto err;
388 }
389
390 ok = 1;
391
392 err:
393 EC_POINT_free(point);
394 return ok;
395 }
396
EC_KEY_key2buf(EC_KEY * key,point_conversion_form_t form,unsigned char ** out_buf,BN_CTX * ctx)397 size_t EC_KEY_key2buf(EC_KEY *key, point_conversion_form_t form,
398 unsigned char **out_buf, BN_CTX *ctx) {
399 if (key == NULL || key->pub_key == NULL || key->group == NULL) {
400 return 0;
401 }
402
403 const size_t len =
404 EC_POINT_point2oct(key->group, key->pub_key, form, NULL, 0, ctx);
405 if (len == 0) {
406 return 0;
407 }
408
409 uint8_t *buf = OPENSSL_malloc(len);
410 if (buf == NULL) {
411 return 0;
412 }
413
414 if (EC_POINT_point2oct(key->group, key->pub_key, form, buf, len, ctx) !=
415 len) {
416 OPENSSL_free(buf);
417 return 0;
418 }
419
420 *out_buf = buf;
421 return len;
422 }
423
EC_KEY_generate_key(EC_KEY * key)424 int EC_KEY_generate_key(EC_KEY *key) {
425 if (key == NULL || key->group == NULL) {
426 OPENSSL_PUT_ERROR(EC, ERR_R_PASSED_NULL_PARAMETER);
427 return 0;
428 }
429
430 // Check that the group order is FIPS compliant (FIPS 186-4 B.4.2).
431 if (BN_num_bits(EC_GROUP_get0_order(key->group)) < 160) {
432 OPENSSL_PUT_ERROR(EC, EC_R_INVALID_GROUP_ORDER);
433 return 0;
434 }
435
436 static const uint8_t kDefaultAdditionalData[32] = {0};
437 EC_WRAPPED_SCALAR *priv_key = ec_wrapped_scalar_new(key->group);
438 EC_POINT *pub_key = EC_POINT_new(key->group);
439 if (priv_key == NULL || pub_key == NULL ||
440 // Generate the private key by testing candidates (FIPS 186-4 B.4.2).
441 !ec_random_nonzero_scalar(key->group, &priv_key->scalar,
442 kDefaultAdditionalData) ||
443 !ec_point_mul_scalar(key->group, &pub_key->raw, &priv_key->scalar, NULL,
444 NULL)) {
445 EC_POINT_free(pub_key);
446 ec_wrapped_scalar_free(priv_key);
447 return 0;
448 }
449
450 ec_wrapped_scalar_free(key->priv_key);
451 key->priv_key = priv_key;
452 EC_POINT_free(key->pub_key);
453 key->pub_key = pub_key;
454 return 1;
455 }
456
EC_KEY_generate_key_fips(EC_KEY * eckey)457 int EC_KEY_generate_key_fips(EC_KEY *eckey) {
458 return EC_KEY_generate_key(eckey) && EC_KEY_check_fips(eckey);
459 }
460
EC_KEY_get_ex_new_index(long argl,void * argp,CRYPTO_EX_unused * unused,CRYPTO_EX_dup * dup_unused,CRYPTO_EX_free * free_func)461 int EC_KEY_get_ex_new_index(long argl, void *argp, CRYPTO_EX_unused *unused,
462 CRYPTO_EX_dup *dup_unused,
463 CRYPTO_EX_free *free_func) {
464 int index;
465 if (!CRYPTO_get_ex_new_index(g_ec_ex_data_class_bss_get(), &index, argl, argp,
466 free_func)) {
467 return -1;
468 }
469 return index;
470 }
471
EC_KEY_set_ex_data(EC_KEY * d,int idx,void * arg)472 int EC_KEY_set_ex_data(EC_KEY *d, int idx, void *arg) {
473 return CRYPTO_set_ex_data(&d->ex_data, idx, arg);
474 }
475
EC_KEY_get_ex_data(const EC_KEY * d,int idx)476 void *EC_KEY_get_ex_data(const EC_KEY *d, int idx) {
477 return CRYPTO_get_ex_data(&d->ex_data, idx);
478 }
479
EC_KEY_set_asn1_flag(EC_KEY * key,int flag)480 void EC_KEY_set_asn1_flag(EC_KEY *key, int flag) {}
481