1 /* $OpenBSD: gostr341001.c,v 1.9 2022/01/07 09:40:03 tb Exp $ */
2 /*
3 * Copyright (c) 2014 Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
4 * Copyright (c) 2005-2006 Cryptocom LTD
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 *
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 *
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in
15 * the documentation and/or other materials provided with the
16 * distribution.
17 *
18 * 3. All advertising materials mentioning features or use of this
19 * software must display the following acknowledgment:
20 * "This product includes software developed by the OpenSSL Project
21 * for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
22 *
23 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
24 * endorse or promote products derived from this software without
25 * prior written permission. For written permission, please contact
26 * openssl-core@openssl.org.
27 *
28 * 5. Products derived from this software may not be called "OpenSSL"
29 * nor may "OpenSSL" appear in their names without prior written
30 * permission of the OpenSSL Project.
31 *
32 * 6. Redistributions of any form whatsoever must retain the following
33 * acknowledgment:
34 * "This product includes software developed by the OpenSSL Project
35 * for use in the OpenSSL Toolkit (http://www.openssl.org/)"
36 *
37 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
38 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
39 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
40 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
41 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
42 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
43 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
44 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
45 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
46 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
47 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
48 * OF THE POSSIBILITY OF SUCH DAMAGE.
49 * ====================================================================
50 */
51
52 #include <string.h>
53
54 #include <openssl/opensslconf.h>
55
56 #ifndef OPENSSL_NO_GOST
57 #include <openssl/bn.h>
58 #include <openssl/err.h>
59 #include <openssl/gost.h>
60
61 #include "bn_lcl.h"
62 #include "ecs_locl.h"
63 #include "gost_locl.h"
64
65 /* Convert little-endian byte array into bignum */
66 BIGNUM *
GOST_le2bn(const unsigned char * buf,size_t len,BIGNUM * bn)67 GOST_le2bn(const unsigned char *buf, size_t len, BIGNUM *bn)
68 {
69 unsigned char temp[64];
70 int i;
71
72 if (len > 64)
73 return NULL;
74
75 for (i = 0; i < len; i++) {
76 temp[len - 1 - i] = buf[i];
77 }
78
79 return BN_bin2bn(temp, len, bn);
80 }
81
82 int
GOST_bn2le(BIGNUM * bn,unsigned char * buf,int len)83 GOST_bn2le(BIGNUM *bn, unsigned char *buf, int len)
84 {
85 unsigned char temp[64];
86 int i, bytes;
87
88 bytes = BN_num_bytes(bn);
89 if (len > 64 || bytes > len)
90 return 0;
91
92 BN_bn2bin(bn, temp);
93
94 for (i = 0; i < bytes; i++) {
95 buf[bytes - 1 - i] = temp[i];
96 }
97
98 memset(buf + bytes, 0, len - bytes);
99
100 return 1;
101 }
102
103 int
gost2001_compute_public(GOST_KEY * ec)104 gost2001_compute_public(GOST_KEY *ec)
105 {
106 const EC_GROUP *group = GOST_KEY_get0_group(ec);
107 EC_POINT *pub_key = NULL;
108 const BIGNUM *priv_key = NULL;
109 BN_CTX *ctx = NULL;
110 int ok = 0;
111
112 if (group == NULL) {
113 GOSTerror(GOST_R_KEY_IS_NOT_INITIALIZED);
114 return 0;
115 }
116 ctx = BN_CTX_new();
117 if (ctx == NULL) {
118 GOSTerror(ERR_R_MALLOC_FAILURE);
119 return 0;
120 }
121 BN_CTX_start(ctx);
122 if ((priv_key = GOST_KEY_get0_private_key(ec)) == NULL)
123 goto err;
124
125 pub_key = EC_POINT_new(group);
126 if (pub_key == NULL)
127 goto err;
128 if (EC_POINT_mul(group, pub_key, priv_key, NULL, NULL, ctx) == 0)
129 goto err;
130 if (GOST_KEY_set_public_key(ec, pub_key) == 0)
131 goto err;
132 ok = 1;
133
134 if (ok == 0) {
135 err:
136 GOSTerror(ERR_R_EC_LIB);
137 }
138 EC_POINT_free(pub_key);
139 if (ctx != NULL) {
140 BN_CTX_end(ctx);
141 BN_CTX_free(ctx);
142 }
143 return ok;
144 }
145
146 ECDSA_SIG *
gost2001_do_sign(BIGNUM * md,GOST_KEY * eckey)147 gost2001_do_sign(BIGNUM *md, GOST_KEY *eckey)
148 {
149 ECDSA_SIG *newsig = NULL;
150 BIGNUM *order = NULL;
151 const EC_GROUP *group;
152 const BIGNUM *priv_key;
153 BIGNUM *r = NULL, *s = NULL, *X = NULL, *tmp = NULL, *tmp2 = NULL, *k =
154 NULL, *e = NULL;
155 EC_POINT *C = NULL;
156 BN_CTX *ctx = BN_CTX_new();
157 int ok = 0;
158
159 if (ctx == NULL) {
160 GOSTerror(ERR_R_MALLOC_FAILURE);
161 return NULL;
162 }
163 BN_CTX_start(ctx);
164 newsig = ECDSA_SIG_new();
165 if (newsig == NULL) {
166 GOSTerror(ERR_R_MALLOC_FAILURE);
167 goto err;
168 }
169 s = newsig->s;
170 r = newsig->r;
171 group = GOST_KEY_get0_group(eckey);
172 if ((order = BN_CTX_get(ctx)) == NULL)
173 goto err;
174 if (EC_GROUP_get_order(group, order, ctx) == 0)
175 goto err;
176 priv_key = GOST_KEY_get0_private_key(eckey);
177 if ((e = BN_CTX_get(ctx)) == NULL)
178 goto err;
179 if (BN_mod_ct(e, md, order, ctx) == 0)
180 goto err;
181 if (BN_is_zero(e))
182 BN_one(e);
183 if ((k = BN_CTX_get(ctx)) == NULL)
184 goto err;
185 if ((X = BN_CTX_get(ctx)) == NULL)
186 goto err;
187 if ((C = EC_POINT_new(group)) == NULL)
188 goto err;
189 do {
190 do {
191 if (!BN_rand_range(k, order)) {
192 GOSTerror(GOST_R_RANDOM_NUMBER_GENERATOR_FAILED);
193 goto err;
194 }
195 /*
196 * We do not want timing information to leak the length
197 * of k, so we compute G*k using an equivalent scalar
198 * of fixed bit-length.
199 */
200 if (BN_add(k, k, order) == 0)
201 goto err;
202 if (BN_num_bits(k) <= BN_num_bits(order))
203 if (BN_add(k, k, order) == 0)
204 goto err;
205
206 if (EC_POINT_mul(group, C, k, NULL, NULL, ctx) == 0) {
207 GOSTerror(ERR_R_EC_LIB);
208 goto err;
209 }
210 if (EC_POINT_get_affine_coordinates(group, C, X,
211 NULL, ctx) == 0) {
212 GOSTerror(ERR_R_EC_LIB);
213 goto err;
214 }
215 if (BN_nnmod(r, X, order, ctx) == 0)
216 goto err;
217 } while (BN_is_zero(r));
218 /* s = (r*priv_key+k*e) mod order */
219 if (tmp == NULL) {
220 if ((tmp = BN_CTX_get(ctx)) == NULL)
221 goto err;
222 }
223 if (BN_mod_mul(tmp, priv_key, r, order, ctx) == 0)
224 goto err;
225 if (tmp2 == NULL) {
226 if ((tmp2 = BN_CTX_get(ctx)) == NULL)
227 goto err;
228 }
229 if (BN_mod_mul(tmp2, k, e, order, ctx) == 0)
230 goto err;
231 if (BN_mod_add(s, tmp, tmp2, order, ctx) == 0)
232 goto err;
233 } while (BN_is_zero(s));
234 ok = 1;
235
236 err:
237 EC_POINT_free(C);
238 if (ctx != NULL) {
239 BN_CTX_end(ctx);
240 BN_CTX_free(ctx);
241 }
242 if (ok == 0) {
243 ECDSA_SIG_free(newsig);
244 newsig = NULL;
245 }
246 return newsig;
247 }
248
249 int
gost2001_do_verify(BIGNUM * md,ECDSA_SIG * sig,GOST_KEY * ec)250 gost2001_do_verify(BIGNUM *md, ECDSA_SIG *sig, GOST_KEY *ec)
251 {
252 BN_CTX *ctx = BN_CTX_new();
253 const EC_GROUP *group = GOST_KEY_get0_group(ec);
254 BIGNUM *order;
255 BIGNUM *e = NULL, *R = NULL, *v = NULL, *z1 = NULL, *z2 = NULL;
256 BIGNUM *X = NULL, *tmp = NULL;
257 EC_POINT *C = NULL;
258 const EC_POINT *pub_key = NULL;
259 int ok = 0;
260
261 if (ctx == NULL)
262 goto err;
263 BN_CTX_start(ctx);
264 if ((order = BN_CTX_get(ctx)) == NULL)
265 goto err;
266 if ((e = BN_CTX_get(ctx)) == NULL)
267 goto err;
268 if ((z1 = BN_CTX_get(ctx)) == NULL)
269 goto err;
270 if ((z2 = BN_CTX_get(ctx)) == NULL)
271 goto err;
272 if ((tmp = BN_CTX_get(ctx)) == NULL)
273 goto err;
274 if ((X = BN_CTX_get(ctx)) == NULL)
275 goto err;
276 if ((R = BN_CTX_get(ctx)) == NULL)
277 goto err;
278 if ((v = BN_CTX_get(ctx)) == NULL)
279 goto err;
280
281 if (EC_GROUP_get_order(group, order, ctx) == 0)
282 goto err;
283 pub_key = GOST_KEY_get0_public_key(ec);
284 if (BN_is_zero(sig->s) || BN_is_zero(sig->r) ||
285 BN_cmp(sig->s, order) >= 1 || BN_cmp(sig->r, order) >= 1) {
286 GOSTerror(GOST_R_SIGNATURE_PARTS_GREATER_THAN_Q);
287 goto err;
288 }
289
290 if (BN_mod_ct(e, md, order, ctx) == 0)
291 goto err;
292 if (BN_is_zero(e))
293 BN_one(e);
294 if ((v = BN_mod_inverse_ct(v, e, order, ctx)) == NULL)
295 goto err;
296 if (BN_mod_mul(z1, sig->s, v, order, ctx) == 0)
297 goto err;
298 if (BN_sub(tmp, order, sig->r) == 0)
299 goto err;
300 if (BN_mod_mul(z2, tmp, v, order, ctx) == 0)
301 goto err;
302 if ((C = EC_POINT_new(group)) == NULL)
303 goto err;
304 if (EC_POINT_mul(group, C, z1, pub_key, z2, ctx) == 0) {
305 GOSTerror(ERR_R_EC_LIB);
306 goto err;
307 }
308 if (EC_POINT_get_affine_coordinates(group, C, X, NULL, ctx) == 0) {
309 GOSTerror(ERR_R_EC_LIB);
310 goto err;
311 }
312 if (BN_mod_ct(R, X, order, ctx) == 0)
313 goto err;
314 if (BN_cmp(R, sig->r) != 0) {
315 GOSTerror(GOST_R_SIGNATURE_MISMATCH);
316 } else {
317 ok = 1;
318 }
319 err:
320 EC_POINT_free(C);
321 if (ctx != NULL) {
322 BN_CTX_end(ctx);
323 BN_CTX_free(ctx);
324 }
325 return ok;
326 }
327
328 /* Implementation of CryptoPro VKO 34.10-2001 algorithm */
329 int
VKO_compute_key(BIGNUM * X,BIGNUM * Y,const GOST_KEY * pkey,GOST_KEY * priv_key,const BIGNUM * ukm)330 VKO_compute_key(BIGNUM *X, BIGNUM *Y, const GOST_KEY *pkey, GOST_KEY *priv_key,
331 const BIGNUM *ukm)
332 {
333 BIGNUM *p = NULL, *order = NULL;
334 const BIGNUM *key = GOST_KEY_get0_private_key(priv_key);
335 const EC_GROUP *group = GOST_KEY_get0_group(priv_key);
336 const EC_POINT *pub_key = GOST_KEY_get0_public_key(pkey);
337 EC_POINT *pnt;
338 BN_CTX *ctx = NULL;
339 int ok = 0;
340
341 pnt = EC_POINT_new(group);
342 if (pnt == NULL)
343 goto err;
344 ctx = BN_CTX_new();
345 if (ctx == NULL)
346 goto err;
347 BN_CTX_start(ctx);
348 if ((p = BN_CTX_get(ctx)) == NULL)
349 goto err;
350 if ((order = BN_CTX_get(ctx)) == NULL)
351 goto err;
352 if (EC_GROUP_get_order(group, order, ctx) == 0)
353 goto err;
354 if (BN_mod_mul(p, key, ukm, order, ctx) == 0)
355 goto err;
356 if (EC_POINT_mul(group, pnt, NULL, pub_key, p, ctx) == 0)
357 goto err;
358 if (EC_POINT_get_affine_coordinates(group, pnt, X, Y, ctx) == 0)
359 goto err;
360 ok = 1;
361
362 err:
363 if (ctx != NULL) {
364 BN_CTX_end(ctx);
365 BN_CTX_free(ctx);
366 }
367 EC_POINT_free(pnt);
368 return ok;
369 }
370
371 int
gost2001_keygen(GOST_KEY * ec)372 gost2001_keygen(GOST_KEY *ec)
373 {
374 BIGNUM *order = BN_new(), *d = BN_new();
375 const EC_GROUP *group = GOST_KEY_get0_group(ec);
376 int rc = 0;
377
378 if (order == NULL || d == NULL)
379 goto err;
380 if (EC_GROUP_get_order(group, order, NULL) == 0)
381 goto err;
382
383 do {
384 if (BN_rand_range(d, order) == 0) {
385 GOSTerror(GOST_R_RANDOM_NUMBER_GENERATOR_FAILED);
386 goto err;
387 }
388 } while (BN_is_zero(d));
389
390 if (GOST_KEY_set_private_key(ec, d) == 0)
391 goto err;
392 rc = gost2001_compute_public(ec);
393
394 err:
395 BN_free(d);
396 BN_free(order);
397 return rc;
398 }
399 #endif
400