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, DSA_SIG *sig);
22 # define dump_signature(a,b,c)
23 # define dump_dsa_sig(a,b)
26 /* Convert little-endian byte array into bignum */
27 BIGNUM *hashsum2bn(const unsigned char *dgst, int len)
29 unsigned char buf[64];
32 if (len > sizeof(buf))
35 for (i = 0; i < len; i++) {
36 buf[len - i - 1] = dgst[i];
38 return BN_bin2bn(buf, len, NULL);
41 static R3410_ec_params *gost_nid2params(int nid)
43 R3410_ec_params *params;
45 /* Search nid in 2012 paramset */
46 params = R3410_2012_512_paramset;
47 while (params->nid != NID_undef) {
48 if (params->nid == nid)
53 /* Search nid in 2001 paramset */
54 params = R3410_2001_paramset;
55 while (params->nid != NID_undef) {
56 if (params->nid == nid)
65 * Fills EC_KEY structure hidden in the app_data field of DSA structure
66 * with parameter information, extracted from parameter array in
69 * Also fils DSA->q field with copy of EC_GROUP order field to make
70 * DSA_size function work
72 int fill_GOST_EC_params(EC_KEY *eckey, int nid)
74 R3410_ec_params *params = gost_nid2params(nid);
77 BIGNUM *p = NULL, *q = NULL, *a = NULL, *b = NULL, *x = NULL, *y = NULL;
81 if (!eckey || !params) {
82 GOSTerr(GOST_F_FILL_GOST_EC_PARAMS, GOST_R_UNSUPPORTED_PARAMETER_SET);
86 if (!(ctx = BN_CTX_new())) {
87 GOSTerr(GOST_F_FILL_GOST_EC_PARAMS, ERR_R_MALLOC_FAILURE);
98 if (!p || !a || !b || !x || !y || !q) {
99 GOSTerr(GOST_F_FILL_GOST_EC_PARAMS, ERR_R_MALLOC_FAILURE);
103 if (!BN_hex2bn(&p, params->p)
104 || !BN_hex2bn(&a, params->a)
105 || !BN_hex2bn(&b, params->b)) {
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_GFp(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, NULL)) {
131 GOSTerr(GOST_F_FILL_GOST_EC_PARAMS, ERR_R_INTERNAL_ERROR);
134 EC_GROUP_set_curve_name(grp, params->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 DSA_SIG structure
154 DSA_SIG *gost_ec_sign(const unsigned char *dgst, int dlen, EC_KEY *eckey)
156 DSA_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_new())) {
172 GOSTerr(GOST_F_GOST_EC_SIGN, ERR_R_MALLOC_FAILURE);
177 OPENSSL_assert(dlen == 32 || dlen == 64);
178 md = hashsum2bn(dgst, dlen);
179 newsig = DSA_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_GFp(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 DSA_SIG_set0(newsig, new_r, new_s);
295 if (!ret && newsig) {
296 DSA_SIG_free(newsig);
302 * Verifies gost ec signature
305 int gost_ec_verify(const unsigned char *dgst, int dgst_len,
306 DSA_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,
312 *z1 = NULL, *z2 = NULL;
313 const BIGNUM *sig_s = NULL, *sig_r = NULL;
314 BIGNUM *X = NULL, *tmp = NULL;
316 const EC_POINT *pub_key = NULL;
319 OPENSSL_assert(dgst != NULL && sig != NULL && group != NULL);
321 if (!(ctx = BN_CTX_new())) {
322 GOSTerr(GOST_F_GOST_EC_VERIFY, ERR_R_MALLOC_FAILURE);
327 order = BN_CTX_get(ctx);
329 z1 = BN_CTX_get(ctx);
330 z2 = BN_CTX_get(ctx);
331 tmp = BN_CTX_get(ctx);
335 if (!order || !e || !z1 || !z2 || !tmp || !X || !R || !v) {
336 GOSTerr(GOST_F_GOST_EC_VERIFY, ERR_R_MALLOC_FAILURE);
340 pub_key = EC_KEY_get0_public_key(ec);
341 if (!pub_key || !EC_GROUP_get_order(group, order, ctx)) {
342 GOSTerr(GOST_F_GOST_EC_VERIFY, ERR_R_INTERNAL_ERROR);
346 DSA_SIG_get0(sig, &sig_r, &sig_s);
348 if (BN_is_zero(sig_s) || BN_is_zero(sig_r) ||
349 (BN_cmp(sig_s, order) >= 1) || (BN_cmp(sig_r, order) >= 1)) {
350 GOSTerr(GOST_F_GOST_EC_VERIFY, GOST_R_SIGNATURE_PARTS_GREATER_THAN_Q);
355 OPENSSL_assert(dgst_len == 32 || dgst_len == 64);
356 md = hashsum2bn(dgst, dgst_len);
357 if (!md || !BN_mod(e, md, order, ctx)) {
358 GOSTerr(GOST_F_GOST_EC_VERIFY, ERR_R_INTERNAL_ERROR);
362 fprintf(stderr, "digest as bignum: ");
363 BN_print_fp(stderr, md);
364 fprintf(stderr, "\ndigest mod q: ");
365 BN_print_fp(stderr, e);
367 if (BN_is_zero(e) && !BN_one(e)) {
368 GOSTerr(GOST_F_GOST_EC_VERIFY, ERR_R_INTERNAL_ERROR);
371 v = BN_mod_inverse(v, e, order, ctx);
372 if (!v || !BN_mod_mul(z1, sig_s, v, order, ctx)
373 || !BN_sub(tmp, order, sig_r)
374 || !BN_mod_mul(z2, tmp, v, order, ctx)) {
375 GOSTerr(GOST_F_GOST_EC_VERIFY, ERR_R_INTERNAL_ERROR);
379 fprintf(stderr, "\nInverted digest value: ");
380 BN_print_fp(stderr, v);
381 fprintf(stderr, "\nz1: ");
382 BN_print_fp(stderr, z1);
383 fprintf(stderr, "\nz2: ");
384 BN_print_fp(stderr, z2);
386 C = EC_POINT_new(group);
388 GOSTerr(GOST_F_GOST_EC_VERIFY, ERR_R_MALLOC_FAILURE);
391 if (!EC_POINT_mul(group, C, z1, pub_key, z2, ctx)) {
392 GOSTerr(GOST_F_GOST_EC_VERIFY, ERR_R_EC_LIB);
395 if (!EC_POINT_get_affine_coordinates_GFp(group, C, X, NULL, ctx)) {
396 GOSTerr(GOST_F_GOST_EC_VERIFY, ERR_R_EC_LIB);
399 if (!BN_mod(R, X, order, ctx)) {
400 GOSTerr(GOST_F_GOST_EC_VERIFY, ERR_R_INTERNAL_ERROR);
404 fprintf(stderr, "\nX=");
405 BN_print_fp(stderr, X);
406 fprintf(stderr, "\nX mod q=");
407 BN_print_fp(stderr, R);
408 fprintf(stderr, "\n");
410 if (BN_cmp(R, sig_r) != 0) {
411 GOSTerr(GOST_F_GOST_EC_VERIFY, GOST_R_SIGNATURE_MISMATCH);
426 * Computes GOST R 34.10-2001 public key
427 * or GOST R 34.10-2012 public key
430 int gost_ec_compute_public(EC_KEY *ec)
432 const EC_GROUP *group = (ec) ? EC_KEY_get0_group(ec) : NULL;
433 EC_POINT *pub_key = NULL;
434 const BIGNUM *priv_key = NULL;
439 GOSTerr(GOST_F_GOST_EC_COMPUTE_PUBLIC, GOST_R_KEY_IS_NOT_INITIALIZED);
445 GOSTerr(GOST_F_GOST_EC_COMPUTE_PUBLIC, ERR_R_MALLOC_FAILURE);
450 priv_key = EC_KEY_get0_private_key(ec);
452 GOSTerr(GOST_F_GOST_EC_COMPUTE_PUBLIC, ERR_R_EC_LIB);
456 pub_key = EC_POINT_new(group);
458 GOSTerr(GOST_F_GOST_EC_COMPUTE_PUBLIC, ERR_R_MALLOC_FAILURE);
462 if (!EC_POINT_mul(group, pub_key, priv_key, NULL, NULL, ctx)) {
463 GOSTerr(GOST_F_GOST_EC_COMPUTE_PUBLIC, ERR_R_EC_LIB);
466 if (!EC_KEY_set_public_key(ec, pub_key)) {
467 GOSTerr(GOST_F_GOST_EC_COMPUTE_PUBLIC, ERR_R_EC_LIB);
473 EC_POINT_free(pub_key);
481 * Generates GOST R 34.10-2001
482 * or GOST R 34.10-2012 keypair
485 int gost_ec_keygen(EC_KEY *ec)
487 BIGNUM *order = NULL, *d = NULL;
488 const EC_GROUP *group = (ec) ? EC_KEY_get0_group(ec) : NULL;
492 GOSTerr(GOST_F_GOST_EC_KEYGEN, ERR_R_INTERNAL_ERROR);
499 GOSTerr(GOST_F_GOST_EC_KEYGEN, ERR_R_MALLOC_FAILURE);
503 if (!EC_GROUP_get_order(group, order, NULL)) {
504 GOSTerr(GOST_F_GOST_EC_KEYGEN, ERR_R_INTERNAL_ERROR);
509 if (!BN_rand_range(d, order)) {
510 GOSTerr(GOST_F_GOST_EC_KEYGEN, GOST_R_RNG_ERROR);
514 while (BN_is_zero(d));
516 if (!EC_KEY_set_private_key(ec, d)) {
517 GOSTerr(GOST_F_GOST_EC_KEYGEN, ERR_R_INTERNAL_ERROR);
528 return (ok) ? gost_ec_compute_public(ec) : 0;