1 /**********************************************************************
3 * Copyright (c) 2005-2013 Cryptocom LTD *
4 * This file is distributed under the same license as OpenSSL *
6 * Implementation of GOST R 34.10-2001 *
7 * Requires OpenSSL 1.0.0+ for compilation *
8 **********************************************************************/
11 #include <openssl/rand.h>
12 #include <openssl/ecdsa.h>
13 #include <openssl/err.h>
14 #include "e_gost_err.h"
17 void dump_signature(const char *message, const unsigned char *buffer,
19 void dump_dsa_sig(const char *message, ECDSA_SIG *sig);
22 # define dump_signature(a,b,c)
23 # define dump_dsa_sig(a,b)
26 static R3410_ec_params *gost_nid2params(int nid)
28 R3410_ec_params *params;
30 /* Map tc26-2012 256-bit parameters to cp-2001 parameters */
32 case NID_id_tc26_gost_3410_2012_256_paramSetB:
33 nid = NID_id_GostR3410_2001_CryptoPro_A_ParamSet;
35 case NID_id_tc26_gost_3410_2012_256_paramSetC:
36 nid = NID_id_GostR3410_2001_CryptoPro_B_ParamSet;
38 case NID_id_tc26_gost_3410_2012_256_paramSetD:
39 nid = NID_id_GostR3410_2001_CryptoPro_C_ParamSet;
42 /* Search nid in 2012 paramset */
43 params = R3410_2012_512_paramset;
44 while (params->nid != NID_undef) {
45 if (params->nid == nid)
50 /* Search nid in 2001 paramset */
51 params = R3410_2001_paramset;
52 while (params->nid != NID_undef) {
53 if (params->nid == nid)
62 * Fills EC_KEY structure hidden in the app_data field of DSA structure
63 * with parameter information, extracted from parameter array in
66 * Also fils DSA->q field with copy of EC_GROUP order field to make
67 * DSA_size function work
69 int fill_GOST_EC_params(EC_KEY *eckey, int nid)
71 R3410_ec_params *params = gost_nid2params(nid);
74 BIGNUM *p = NULL, *q = NULL, *a = NULL, *b = NULL, *x = NULL, *y =
75 NULL, *cofactor = NULL;
79 if (!eckey || !params) {
80 GOSTerr(GOST_F_FILL_GOST_EC_PARAMS, GOST_R_UNSUPPORTED_PARAMETER_SET);
84 if (!(ctx = BN_CTX_new())) {
85 GOSTerr(GOST_F_FILL_GOST_EC_PARAMS, ERR_R_MALLOC_FAILURE);
96 cofactor = BN_CTX_get(ctx);
97 if (!p || !a || !b || !x || !y || !q || !cofactor) {
98 GOSTerr(GOST_F_FILL_GOST_EC_PARAMS, ERR_R_MALLOC_FAILURE);
102 if (!BN_hex2bn(&p, params->p)
103 || !BN_hex2bn(&a, params->a)
104 || !BN_hex2bn(&b, params->b)
105 || !BN_hex2bn(&cofactor, params->cofactor)) {
106 GOSTerr(GOST_F_FILL_GOST_EC_PARAMS, ERR_R_INTERNAL_ERROR);
110 grp = EC_GROUP_new_curve_GFp(p, a, b, ctx);
112 GOSTerr(GOST_F_FILL_GOST_EC_PARAMS, ERR_R_MALLOC_FAILURE);
116 P = EC_POINT_new(grp);
118 GOSTerr(GOST_F_FILL_GOST_EC_PARAMS, ERR_R_MALLOC_FAILURE);
122 if (!BN_hex2bn(&x, params->x)
123 || !BN_hex2bn(&y, params->y)
124 || !EC_POINT_set_affine_coordinates(grp, P, x, y, ctx)
125 || !BN_hex2bn(&q, params->q)) {
126 GOSTerr(GOST_F_FILL_GOST_EC_PARAMS, ERR_R_INTERNAL_ERROR);
130 if (!EC_GROUP_set_generator(grp, P, q, cofactor)) {
131 GOSTerr(GOST_F_FILL_GOST_EC_PARAMS, ERR_R_INTERNAL_ERROR);
134 EC_GROUP_set_curve_name(grp, nid);
135 if (!EC_KEY_set_group(eckey, grp)) {
136 GOSTerr(GOST_F_FILL_GOST_EC_PARAMS, ERR_R_INTERNAL_ERROR);
151 * Computes gost_ec signature as ECDSA_SIG structure
154 ECDSA_SIG *gost_ec_sign(const unsigned char *dgst, int dlen, EC_KEY *eckey)
156 ECDSA_SIG *newsig = NULL, *ret = NULL;
158 BIGNUM *order = NULL;
159 const EC_GROUP *group;
160 const BIGNUM *priv_key;
161 BIGNUM *r = NULL, *s = NULL, *X = NULL, *tmp = NULL, *tmp2 = NULL,
162 *k = NULL, *e = NULL;
164 BIGNUM *new_r = NULL, *new_s = NULL;
169 OPENSSL_assert(dgst != NULL && eckey != NULL);
171 if (!(ctx = BN_CTX_secure_new())) {
172 GOSTerr(GOST_F_GOST_EC_SIGN, ERR_R_MALLOC_FAILURE);
177 OPENSSL_assert(dlen == 32 || dlen == 64);
178 md = BN_lebin2bn(dgst, dlen, NULL);
179 newsig = ECDSA_SIG_new();
180 if (!newsig || !md) {
181 GOSTerr(GOST_F_GOST_EC_SIGN, ERR_R_MALLOC_FAILURE);
184 group = EC_KEY_get0_group(eckey);
186 GOSTerr(GOST_F_GOST_EC_SIGN, ERR_R_INTERNAL_ERROR);
189 order = BN_CTX_get(ctx);
190 if (!order || !EC_GROUP_get_order(group, order, ctx)) {
191 GOSTerr(GOST_F_GOST_EC_SIGN, ERR_R_INTERNAL_ERROR);
194 priv_key = EC_KEY_get0_private_key(eckey);
196 GOSTerr(GOST_F_GOST_EC_SIGN, ERR_R_INTERNAL_ERROR);
200 if (!e || !BN_mod(e, md, order, ctx)) {
201 GOSTerr(GOST_F_GOST_EC_SIGN, ERR_R_INTERNAL_ERROR);
205 fprintf(stderr, "digest as bignum=");
206 BN_print_fp(stderr, md);
207 fprintf(stderr, "\ndigest mod q=");
208 BN_print_fp(stderr, e);
209 fprintf(stderr, "\n");
215 C = EC_POINT_new(group);
217 GOSTerr(GOST_F_GOST_EC_SIGN, ERR_R_MALLOC_FAILURE);
223 if (!BN_rand_range(k, order)) {
224 GOSTerr(GOST_F_GOST_EC_SIGN, GOST_R_RNG_ERROR);
228 * To avoid timing information leaking the length of k,
229 * compute C*k using an equivalent scalar of fixed bit-length */
230 if (!BN_add(k, k, order)
231 || (BN_num_bits(k) <= BN_num_bits(order)
232 && !BN_add(k, k, order))) {
235 if (!EC_POINT_mul(group, C, k, NULL, NULL, ctx)) {
236 GOSTerr(GOST_F_GOST_EC_SIGN, ERR_R_EC_LIB);
244 GOSTerr(GOST_F_GOST_EC_SIGN, ERR_R_MALLOC_FAILURE);
247 if (!EC_POINT_get_affine_coordinates(group, C, X, NULL, ctx)) {
248 GOSTerr(GOST_F_GOST_EC_SIGN, ERR_R_EC_LIB);
252 if (!BN_nnmod(r, X, order, ctx)) {
253 GOSTerr(GOST_F_GOST_EC_SIGN, ERR_R_INTERNAL_ERROR);
257 while (BN_is_zero(r));
258 /* s = (r*priv_key+k*e) mod order */
260 tmp = BN_CTX_get(ctx);
262 tmp2 = BN_CTX_get(ctx);
265 if (!tmp || !tmp2 || !s) {
266 GOSTerr(GOST_F_GOST_EC_SIGN, ERR_R_MALLOC_FAILURE);
270 if (!BN_mod_mul(tmp, priv_key, r, order, ctx)
271 || !BN_mod_mul(tmp2, k, e, order, ctx)
272 || !BN_mod_add(s, tmp, tmp2, order, ctx)) {
273 GOSTerr(GOST_F_GOST_EC_SIGN, ERR_R_INTERNAL_ERROR);
277 while (BN_is_zero(s));
281 if (!new_s || !new_r) {
282 GOSTerr(GOST_F_GOST_EC_SIGN, ERR_R_MALLOC_FAILURE);
285 ECDSA_SIG_set0(newsig, new_r, new_s);
295 if (!ret && newsig) {
296 ECDSA_SIG_free(newsig);
302 * Verifies gost ec signature
305 int gost_ec_verify(const unsigned char *dgst, int dgst_len,
306 ECDSA_SIG *sig, EC_KEY *ec)
309 const EC_GROUP *group = (ec) ? EC_KEY_get0_group(ec) : NULL;
311 BIGNUM *md = NULL, *e = NULL, *R = NULL, *v = NULL, *z1 = NULL, *z2 = NULL;
312 const BIGNUM *sig_s = NULL, *sig_r = NULL;
313 BIGNUM *X = NULL, *tmp = NULL;
315 const EC_POINT *pub_key = NULL;
318 OPENSSL_assert(dgst != NULL && sig != NULL && group != NULL);
320 if (!(ctx = BN_CTX_new())) {
321 GOSTerr(GOST_F_GOST_EC_VERIFY, ERR_R_MALLOC_FAILURE);
326 order = BN_CTX_get(ctx);
328 z1 = BN_CTX_get(ctx);
329 z2 = BN_CTX_get(ctx);
330 tmp = BN_CTX_get(ctx);
334 if (!order || !e || !z1 || !z2 || !tmp || !X || !R || !v) {
335 GOSTerr(GOST_F_GOST_EC_VERIFY, ERR_R_MALLOC_FAILURE);
339 pub_key = EC_KEY_get0_public_key(ec);
340 if (!pub_key || !EC_GROUP_get_order(group, order, ctx)) {
341 GOSTerr(GOST_F_GOST_EC_VERIFY, ERR_R_INTERNAL_ERROR);
345 ECDSA_SIG_get0(sig, &sig_r, &sig_s);
347 if (BN_is_zero(sig_s) || BN_is_zero(sig_r) ||
348 (BN_cmp(sig_s, order) >= 1) || (BN_cmp(sig_r, order) >= 1)) {
349 GOSTerr(GOST_F_GOST_EC_VERIFY, GOST_R_SIGNATURE_PARTS_GREATER_THAN_Q);
354 OPENSSL_assert(dgst_len == 32 || dgst_len == 64);
355 md = BN_lebin2bn(dgst, dgst_len, NULL);
356 if (!md || !BN_mod(e, md, order, ctx)) {
357 GOSTerr(GOST_F_GOST_EC_VERIFY, ERR_R_INTERNAL_ERROR);
361 fprintf(stderr, "digest as bignum: ");
362 BN_print_fp(stderr, md);
363 fprintf(stderr, "\ndigest mod q: ");
364 BN_print_fp(stderr, e);
366 if (BN_is_zero(e) && !BN_one(e)) {
367 GOSTerr(GOST_F_GOST_EC_VERIFY, ERR_R_INTERNAL_ERROR);
370 v = BN_mod_inverse(v, e, order, ctx);
371 if (!v || !BN_mod_mul(z1, sig_s, v, order, ctx)
372 || !BN_sub(tmp, order, sig_r)
373 || !BN_mod_mul(z2, tmp, v, order, ctx)) {
374 GOSTerr(GOST_F_GOST_EC_VERIFY, ERR_R_INTERNAL_ERROR);
378 fprintf(stderr, "\nInverted digest value: ");
379 BN_print_fp(stderr, v);
380 fprintf(stderr, "\nz1: ");
381 BN_print_fp(stderr, z1);
382 fprintf(stderr, "\nz2: ");
383 BN_print_fp(stderr, z2);
385 C = EC_POINT_new(group);
387 GOSTerr(GOST_F_GOST_EC_VERIFY, ERR_R_MALLOC_FAILURE);
390 if (!EC_POINT_mul(group, C, z1, pub_key, z2, ctx)) {
391 GOSTerr(GOST_F_GOST_EC_VERIFY, ERR_R_EC_LIB);
394 if (!EC_POINT_get_affine_coordinates(group, C, X, NULL, ctx)) {
395 GOSTerr(GOST_F_GOST_EC_VERIFY, ERR_R_EC_LIB);
398 if (!BN_mod(R, X, order, ctx)) {
399 GOSTerr(GOST_F_GOST_EC_VERIFY, ERR_R_INTERNAL_ERROR);
403 fprintf(stderr, "\nX=");
404 BN_print_fp(stderr, X);
405 fprintf(stderr, "\nX mod q=");
406 BN_print_fp(stderr, R);
407 fprintf(stderr, "\n");
409 if (BN_cmp(R, sig_r) != 0) {
410 GOSTerr(GOST_F_GOST_EC_VERIFY, GOST_R_SIGNATURE_MISMATCH);
425 * Computes GOST R 34.10-2001 public key
426 * or GOST R 34.10-2012 public key
429 int gost_ec_compute_public(EC_KEY *ec)
431 const EC_GROUP *group = (ec) ? EC_KEY_get0_group(ec) : NULL;
432 EC_POINT *pub_key = NULL;
433 const BIGNUM *priv_key = NULL;
438 GOSTerr(GOST_F_GOST_EC_COMPUTE_PUBLIC, GOST_R_KEY_IS_NOT_INITIALIZED);
442 ctx = BN_CTX_secure_new();
444 GOSTerr(GOST_F_GOST_EC_COMPUTE_PUBLIC, ERR_R_MALLOC_FAILURE);
449 priv_key = EC_KEY_get0_private_key(ec);
451 GOSTerr(GOST_F_GOST_EC_COMPUTE_PUBLIC, ERR_R_EC_LIB);
455 pub_key = EC_POINT_new(group);
457 GOSTerr(GOST_F_GOST_EC_COMPUTE_PUBLIC, ERR_R_MALLOC_FAILURE);
461 if (!EC_POINT_mul(group, pub_key, priv_key, NULL, NULL, ctx)) {
462 GOSTerr(GOST_F_GOST_EC_COMPUTE_PUBLIC, ERR_R_EC_LIB);
465 if (!EC_KEY_set_public_key(ec, pub_key)) {
466 GOSTerr(GOST_F_GOST_EC_COMPUTE_PUBLIC, ERR_R_EC_LIB);
472 EC_POINT_free(pub_key);
480 * Generates GOST R 34.10-2001
481 * or GOST R 34.10-2012 keypair
484 int gost_ec_keygen(EC_KEY *ec)
486 BIGNUM *order = NULL, *d = NULL;
487 const EC_GROUP *group = (ec) ? EC_KEY_get0_group(ec) : NULL;
491 GOSTerr(GOST_F_GOST_EC_KEYGEN, ERR_R_INTERNAL_ERROR);
498 GOSTerr(GOST_F_GOST_EC_KEYGEN, ERR_R_MALLOC_FAILURE);
502 if (!EC_GROUP_get_order(group, order, NULL)) {
503 GOSTerr(GOST_F_GOST_EC_KEYGEN, ERR_R_INTERNAL_ERROR);
508 if (!BN_rand_range(d, order)) {
509 GOSTerr(GOST_F_GOST_EC_KEYGEN, GOST_R_RNG_ERROR);
513 while (BN_is_zero(d));
515 if (!EC_KEY_set_private_key(ec, d)) {
516 GOSTerr(GOST_F_GOST_EC_KEYGEN, ERR_R_INTERNAL_ERROR);
527 return (ok) ? gost_ec_compute_public(ec) : 0;