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
175 CRYPTO_free_ex_data(g_ec_ex_data_class_bss_get(), r, &r->ex_data);
176
177 OPENSSL_free(r);
178 }
179
EC_KEY_dup(const EC_KEY * src)180 EC_KEY *EC_KEY_dup(const EC_KEY *src) {
181 if (src == NULL) {
182 OPENSSL_PUT_ERROR(EC, ERR_R_PASSED_NULL_PARAMETER);
183 return NULL;
184 }
185
186 EC_KEY *ret = EC_KEY_new();
187 if (ret == NULL) {
188 return NULL;
189 }
190
191 if ((src->group != NULL &&
192 !EC_KEY_set_group(ret, src->group)) ||
193 (src->pub_key != NULL &&
194 !EC_KEY_set_public_key(ret, src->pub_key)) ||
195 (src->priv_key != NULL &&
196 !EC_KEY_set_private_key(ret, EC_KEY_get0_private_key(src)))) {
197 EC_KEY_free(ret);
198 return NULL;
199 }
200
201 ret->enc_flag = src->enc_flag;
202 ret->conv_form = src->conv_form;
203 return ret;
204 }
205
EC_KEY_up_ref(EC_KEY * r)206 int EC_KEY_up_ref(EC_KEY *r) {
207 CRYPTO_refcount_inc(&r->references);
208 return 1;
209 }
210
EC_KEY_is_opaque(const EC_KEY * key)211 int EC_KEY_is_opaque(const EC_KEY *key) {
212 return key->ecdsa_meth && (key->ecdsa_meth->flags & ECDSA_FLAG_OPAQUE);
213 }
214
EC_KEY_get0_group(const EC_KEY * key)215 const EC_GROUP *EC_KEY_get0_group(const EC_KEY *key) { return key->group; }
216
EC_KEY_set_group(EC_KEY * key,const EC_GROUP * group)217 int EC_KEY_set_group(EC_KEY *key, const EC_GROUP *group) {
218 // If |key| already has a group, it is an error to switch to another one.
219 if (key->group != NULL) {
220 if (EC_GROUP_cmp(key->group, group, NULL) != 0) {
221 OPENSSL_PUT_ERROR(EC, EC_R_GROUP_MISMATCH);
222 return 0;
223 }
224 return 1;
225 }
226
227 assert(key->priv_key == NULL);
228 assert(key->pub_key == NULL);
229
230 EC_GROUP_free(key->group);
231 key->group = EC_GROUP_dup(group);
232 return key->group != NULL;
233 }
234
EC_KEY_get0_private_key(const EC_KEY * key)235 const BIGNUM *EC_KEY_get0_private_key(const EC_KEY *key) {
236 return key->priv_key != NULL ? &key->priv_key->bignum : NULL;
237 }
238
EC_KEY_set_private_key(EC_KEY * key,const BIGNUM * priv_key)239 int EC_KEY_set_private_key(EC_KEY *key, const BIGNUM *priv_key) {
240 if (key->group == NULL) {
241 OPENSSL_PUT_ERROR(EC, EC_R_MISSING_PARAMETERS);
242 return 0;
243 }
244
245 EC_WRAPPED_SCALAR *scalar = ec_wrapped_scalar_new(key->group);
246 if (scalar == NULL) {
247 return 0;
248 }
249 if (!ec_bignum_to_scalar(key->group, &scalar->scalar, priv_key)) {
250 OPENSSL_PUT_ERROR(EC, EC_R_WRONG_ORDER);
251 ec_wrapped_scalar_free(scalar);
252 return 0;
253 }
254 ec_wrapped_scalar_free(key->priv_key);
255 key->priv_key = scalar;
256 return 1;
257 }
258
EC_KEY_get0_public_key(const EC_KEY * key)259 const EC_POINT *EC_KEY_get0_public_key(const EC_KEY *key) {
260 return key->pub_key;
261 }
262
EC_KEY_set_public_key(EC_KEY * key,const EC_POINT * pub_key)263 int EC_KEY_set_public_key(EC_KEY *key, const EC_POINT *pub_key) {
264 if (key->group == NULL) {
265 OPENSSL_PUT_ERROR(EC, EC_R_MISSING_PARAMETERS);
266 return 0;
267 }
268
269 if (pub_key != NULL && EC_GROUP_cmp(key->group, pub_key->group, NULL) != 0) {
270 OPENSSL_PUT_ERROR(EC, EC_R_GROUP_MISMATCH);
271 return 0;
272 }
273
274 EC_POINT_free(key->pub_key);
275 key->pub_key = EC_POINT_dup(pub_key, key->group);
276 return (key->pub_key == NULL) ? 0 : 1;
277 }
278
EC_KEY_get_enc_flags(const EC_KEY * key)279 unsigned int EC_KEY_get_enc_flags(const EC_KEY *key) { return key->enc_flag; }
280
EC_KEY_set_enc_flags(EC_KEY * key,unsigned int flags)281 void EC_KEY_set_enc_flags(EC_KEY *key, unsigned int flags) {
282 key->enc_flag = flags;
283 }
284
EC_KEY_get_conv_form(const EC_KEY * key)285 point_conversion_form_t EC_KEY_get_conv_form(const EC_KEY *key) {
286 return key->conv_form;
287 }
288
EC_KEY_set_conv_form(EC_KEY * key,point_conversion_form_t cform)289 void EC_KEY_set_conv_form(EC_KEY *key, point_conversion_form_t cform) {
290 key->conv_form = cform;
291 }
292
EC_KEY_check_key(const EC_KEY * eckey)293 int EC_KEY_check_key(const EC_KEY *eckey) {
294 if (!eckey || !eckey->group || !eckey->pub_key) {
295 OPENSSL_PUT_ERROR(EC, ERR_R_PASSED_NULL_PARAMETER);
296 return 0;
297 }
298
299 if (EC_POINT_is_at_infinity(eckey->group, eckey->pub_key)) {
300 OPENSSL_PUT_ERROR(EC, EC_R_POINT_AT_INFINITY);
301 return 0;
302 }
303
304 // Test whether the public key is on the elliptic curve.
305 if (!EC_POINT_is_on_curve(eckey->group, eckey->pub_key, NULL)) {
306 OPENSSL_PUT_ERROR(EC, EC_R_POINT_IS_NOT_ON_CURVE);
307 return 0;
308 }
309
310 // Check the public and private keys match.
311 if (eckey->priv_key != NULL) {
312 EC_RAW_POINT point;
313 if (!ec_point_mul_scalar_base(eckey->group, &point,
314 &eckey->priv_key->scalar)) {
315 OPENSSL_PUT_ERROR(EC, ERR_R_EC_LIB);
316 return 0;
317 }
318 if (!ec_GFp_simple_points_equal(eckey->group, &point,
319 &eckey->pub_key->raw)) {
320 OPENSSL_PUT_ERROR(EC, EC_R_INVALID_PRIVATE_KEY);
321 return 0;
322 }
323 }
324
325 return 1;
326 }
327
EC_KEY_check_fips(const EC_KEY * key)328 int EC_KEY_check_fips(const EC_KEY *key) {
329 if (EC_KEY_is_opaque(key)) {
330 // Opaque keys can't be checked.
331 OPENSSL_PUT_ERROR(EC, EC_R_PUBLIC_KEY_VALIDATION_FAILED);
332 return 0;
333 }
334
335 if (!EC_KEY_check_key(key)) {
336 return 0;
337 }
338
339 if (key->priv_key) {
340 uint8_t data[16] = {0};
341 ECDSA_SIG *sig = ECDSA_do_sign(data, sizeof(data), key);
342 #if defined(BORINGSSL_FIPS_BREAK_ECDSA_PWCT)
343 data[0] = ~data[0];
344 #endif
345 int ok = sig != NULL &&
346 ECDSA_do_verify(data, sizeof(data), sig, key);
347 ECDSA_SIG_free(sig);
348 if (!ok) {
349 OPENSSL_PUT_ERROR(EC, EC_R_PUBLIC_KEY_VALIDATION_FAILED);
350 return 0;
351 }
352 }
353
354 return 1;
355 }
356
EC_KEY_set_public_key_affine_coordinates(EC_KEY * key,const BIGNUM * x,const BIGNUM * y)357 int EC_KEY_set_public_key_affine_coordinates(EC_KEY *key, const BIGNUM *x,
358 const BIGNUM *y) {
359 EC_POINT *point = NULL;
360 int ok = 0;
361
362 if (!key || !key->group || !x || !y) {
363 OPENSSL_PUT_ERROR(EC, ERR_R_PASSED_NULL_PARAMETER);
364 return 0;
365 }
366
367 point = EC_POINT_new(key->group);
368 if (point == NULL ||
369 !EC_POINT_set_affine_coordinates_GFp(key->group, point, x, y, NULL) ||
370 !EC_KEY_set_public_key(key, point) ||
371 !EC_KEY_check_key(key)) {
372 goto err;
373 }
374
375 ok = 1;
376
377 err:
378 EC_POINT_free(point);
379 return ok;
380 }
381
EC_KEY_key2buf(const EC_KEY * key,point_conversion_form_t form,unsigned char ** out_buf,BN_CTX * ctx)382 size_t EC_KEY_key2buf(const EC_KEY *key, point_conversion_form_t form,
383 unsigned char **out_buf, BN_CTX *ctx) {
384 if (key == NULL || key->pub_key == NULL || key->group == NULL) {
385 return 0;
386 }
387
388 const size_t len =
389 EC_POINT_point2oct(key->group, key->pub_key, form, NULL, 0, ctx);
390 if (len == 0) {
391 return 0;
392 }
393
394 uint8_t *buf = OPENSSL_malloc(len);
395 if (buf == NULL) {
396 return 0;
397 }
398
399 if (EC_POINT_point2oct(key->group, key->pub_key, form, buf, len, ctx) !=
400 len) {
401 OPENSSL_free(buf);
402 return 0;
403 }
404
405 *out_buf = buf;
406 return len;
407 }
408
EC_KEY_generate_key(EC_KEY * key)409 int EC_KEY_generate_key(EC_KEY *key) {
410 if (key == NULL || key->group == NULL) {
411 OPENSSL_PUT_ERROR(EC, ERR_R_PASSED_NULL_PARAMETER);
412 return 0;
413 }
414
415 // Check that the group order is FIPS compliant (FIPS 186-4 B.4.2).
416 if (BN_num_bits(EC_GROUP_get0_order(key->group)) < 160) {
417 OPENSSL_PUT_ERROR(EC, EC_R_INVALID_GROUP_ORDER);
418 return 0;
419 }
420
421 static const uint8_t kDefaultAdditionalData[32] = {0};
422 EC_WRAPPED_SCALAR *priv_key = ec_wrapped_scalar_new(key->group);
423 EC_POINT *pub_key = EC_POINT_new(key->group);
424 if (priv_key == NULL || pub_key == NULL ||
425 // Generate the private key by testing candidates (FIPS 186-4 B.4.2).
426 !ec_random_nonzero_scalar(key->group, &priv_key->scalar,
427 kDefaultAdditionalData) ||
428 !ec_point_mul_scalar_base(key->group, &pub_key->raw, &priv_key->scalar)) {
429 EC_POINT_free(pub_key);
430 ec_wrapped_scalar_free(priv_key);
431 return 0;
432 }
433
434 ec_wrapped_scalar_free(key->priv_key);
435 key->priv_key = priv_key;
436 EC_POINT_free(key->pub_key);
437 key->pub_key = pub_key;
438 return 1;
439 }
440
EC_KEY_generate_key_fips(EC_KEY * eckey)441 int EC_KEY_generate_key_fips(EC_KEY *eckey) {
442 if (EC_KEY_generate_key(eckey) && EC_KEY_check_fips(eckey)) {
443 return 1;
444 }
445
446 EC_POINT_free(eckey->pub_key);
447 ec_wrapped_scalar_free(eckey->priv_key);
448 eckey->pub_key = NULL;
449 eckey->priv_key = NULL;
450 return 0;
451 }
452
EC_KEY_get_ex_new_index(long argl,void * argp,CRYPTO_EX_unused * unused,CRYPTO_EX_dup * dup_unused,CRYPTO_EX_free * free_func)453 int EC_KEY_get_ex_new_index(long argl, void *argp, CRYPTO_EX_unused *unused,
454 CRYPTO_EX_dup *dup_unused,
455 CRYPTO_EX_free *free_func) {
456 int index;
457 if (!CRYPTO_get_ex_new_index(g_ec_ex_data_class_bss_get(), &index, argl, argp,
458 free_func)) {
459 return -1;
460 }
461 return index;
462 }
463
EC_KEY_set_ex_data(EC_KEY * d,int idx,void * arg)464 int EC_KEY_set_ex_data(EC_KEY *d, int idx, void *arg) {
465 return CRYPTO_set_ex_data(&d->ex_data, idx, arg);
466 }
467
EC_KEY_get_ex_data(const EC_KEY * d,int idx)468 void *EC_KEY_get_ex_data(const EC_KEY *d, int idx) {
469 return CRYPTO_get_ex_data(&d->ex_data, idx);
470 }
471
EC_KEY_set_asn1_flag(EC_KEY * key,int flag)472 void EC_KEY_set_asn1_flag(EC_KEY *key, int flag) {}
473