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 getbnfrombuf(buf, len);
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;
166 OPENSSL_assert(dgst != NULL && eckey != NULL);
168 if (!(ctx = BN_CTX_new())) {
169 GOSTerr(GOST_F_GOST_EC_SIGN, ERR_R_MALLOC_FAILURE);
174 OPENSSL_assert(dlen == 32 || dlen == 64);
175 md = hashsum2bn(dgst, dlen);
176 newsig = DSA_SIG_new();
177 if (!newsig || !md) {
178 GOSTerr(GOST_F_GOST_EC_SIGN, GOST_R_NO_MEMORY);
181 group = EC_KEY_get0_group(eckey);
183 GOSTerr(GOST_F_GOST_EC_SIGN, ERR_R_INTERNAL_ERROR);
186 order = BN_CTX_get(ctx);
187 if (!order || !EC_GROUP_get_order(group, order, ctx)) {
188 GOSTerr(GOST_F_GOST_EC_SIGN, ERR_R_INTERNAL_ERROR);
191 priv_key = EC_KEY_get0_private_key(eckey);
193 GOSTerr(GOST_F_GOST_EC_SIGN, ERR_R_INTERNAL_ERROR);
197 if (!e || !BN_mod(e, md, order, ctx)) {
198 GOSTerr(GOST_F_GOST_EC_SIGN, ERR_R_INTERNAL_ERROR);
202 fprintf(stderr, "digest as bignum=");
203 BN_print_fp(stderr, md);
204 fprintf(stderr, "\ndigest mod q=");
205 BN_print_fp(stderr, e);
206 fprintf(stderr, "\n");
212 C = EC_POINT_new(group);
214 GOSTerr(GOST_F_GOST_EC_SIGN, ERR_R_MALLOC_FAILURE);
220 if (!BN_rand_range(k, order)) {
221 GOSTerr(GOST_F_GOST_EC_SIGN,
222 GOST_R_RANDOM_NUMBER_GENERATOR_FAILED);
226 * To avoid timing information leaking the length of k,
227 * compute C*k using an equivalent scalar of fixed bit-length */
228 if (!BN_add(k, k, order)
229 || (BN_num_bits(k) <= BN_num_bits(order)
230 && !BN_add(k, k, order))) {
233 if (!EC_POINT_mul(group, C, k, NULL, NULL, ctx)) {
234 GOSTerr(GOST_F_GOST_EC_SIGN, ERR_R_EC_LIB);
242 GOSTerr(GOST_F_GOST_EC_SIGN, ERR_R_MALLOC_FAILURE);
245 if (!EC_POINT_get_affine_coordinates_GFp(group, C, X, NULL, ctx)) {
246 GOSTerr(GOST_F_GOST_EC_SIGN, ERR_R_EC_LIB);
250 if (!BN_nnmod(r, X, order, ctx)) {
251 GOSTerr(GOST_F_GOST_EC_SIGN, ERR_R_INTERNAL_ERROR);
255 while (BN_is_zero(r));
256 /* s = (r*priv_key+k*e) mod order */
258 tmp = BN_CTX_get(ctx);
260 tmp2 = BN_CTX_get(ctx);
263 if (!tmp || !tmp2 || !s) {
264 GOSTerr(GOST_F_GOST_EC_SIGN, ERR_R_MALLOC_FAILURE);
268 if (!BN_mod_mul(tmp, priv_key, r, order, ctx)
269 || !BN_mod_mul(tmp2, k, e, order, ctx)
270 || !BN_mod_add(s, tmp, tmp2, order, ctx)) {
271 GOSTerr(GOST_F_GOST_EC_SIGN, ERR_R_INTERNAL_ERROR);
275 while (BN_is_zero(s));
277 newsig->s = BN_dup(s);
278 newsig->r = BN_dup(r);
279 if (!newsig->s || !newsig->r) {
280 GOSTerr(GOST_F_GOST_EC_SIGN, ERR_R_MALLOC_FAILURE);
292 if (!ret && newsig) {
293 DSA_SIG_free(newsig);
299 * Verifies gost ec signature
302 int gost_ec_verify(const unsigned char *dgst, int dgst_len,
303 DSA_SIG *sig, EC_KEY *ec)
306 const EC_GROUP *group = (ec) ? EC_KEY_get0_group(ec) : NULL;
308 BIGNUM *md = NULL, *e = NULL, *R = NULL, *v = NULL,
309 *z1 = NULL, *z2 = NULL;
310 BIGNUM *X = NULL, *tmp = NULL;
312 const EC_POINT *pub_key = NULL;
315 OPENSSL_assert(dgst != NULL && sig != NULL && group != NULL);
317 if (!(ctx = BN_CTX_new())) {
318 GOSTerr(GOST_F_GOST_EC_VERIFY, GOST_R_NO_MEMORY);
323 order = BN_CTX_get(ctx);
325 z1 = BN_CTX_get(ctx);
326 z2 = BN_CTX_get(ctx);
327 tmp = BN_CTX_get(ctx);
331 if (!order || !e || !z1 || !z2 || !tmp || !X || !R || !v) {
332 GOSTerr(GOST_F_GOST_EC_VERIFY, ERR_R_MALLOC_FAILURE);
336 pub_key = EC_KEY_get0_public_key(ec);
337 if (!pub_key || !EC_GROUP_get_order(group, order, ctx)) {
338 GOSTerr(GOST_F_GOST_EC_VERIFY, ERR_R_INTERNAL_ERROR);
342 if (BN_is_zero(sig->s) || BN_is_zero(sig->r) ||
343 (BN_cmp(sig->s, order) >= 1) || (BN_cmp(sig->r, order) >= 1)) {
344 GOSTerr(GOST_F_GOST_EC_VERIFY, GOST_R_SIGNATURE_PARTS_GREATER_THAN_Q);
349 OPENSSL_assert(dgst_len == 32 || dgst_len == 64);
350 md = hashsum2bn(dgst, dgst_len);
351 if (!md || !BN_mod(e, md, order, ctx)) {
352 GOSTerr(GOST_F_GOST_EC_VERIFY, ERR_R_INTERNAL_ERROR);
356 fprintf(stderr, "digest as bignum: ");
357 BN_print_fp(stderr, md);
358 fprintf(stderr, "\ndigest mod q: ");
359 BN_print_fp(stderr, e);
361 if (BN_is_zero(e) && !BN_one(e)) {
362 GOSTerr(GOST_F_GOST_EC_VERIFY, ERR_R_INTERNAL_ERROR);
365 v = BN_mod_inverse(v, e, order, ctx);
367 || !BN_mod_mul(z1, sig->s, v, order, ctx)
368 || !BN_sub(tmp, order, sig->r)
369 || !BN_mod_mul(z2, tmp, v, order, ctx)) {
370 GOSTerr(GOST_F_GOST_EC_VERIFY, ERR_R_INTERNAL_ERROR);
374 fprintf(stderr, "\nInverted digest value: ");
375 BN_print_fp(stderr, v);
376 fprintf(stderr, "\nz1: ");
377 BN_print_fp(stderr, z1);
378 fprintf(stderr, "\nz2: ");
379 BN_print_fp(stderr, z2);
381 C = EC_POINT_new(group);
383 GOSTerr(GOST_F_GOST_EC_VERIFY, ERR_R_MALLOC_FAILURE);
386 if (!EC_POINT_mul(group, C, z1, pub_key, z2, ctx)) {
387 GOSTerr(GOST_F_GOST_EC_VERIFY, ERR_R_EC_LIB);
390 if (!EC_POINT_get_affine_coordinates_GFp(group, C, X, NULL, ctx)) {
391 GOSTerr(GOST_F_GOST_EC_VERIFY, ERR_R_EC_LIB);
394 if (!BN_mod(R, X, order, ctx)) {
395 GOSTerr(GOST_F_GOST_EC_VERIFY, ERR_R_INTERNAL_ERROR);
399 fprintf(stderr, "\nX=");
400 BN_print_fp(stderr, X);
401 fprintf(stderr, "\nX mod q=");
402 BN_print_fp(stderr, R);
403 fprintf(stderr, "\n");
405 if (BN_cmp(R, sig->r) != 0) {
406 GOSTerr(GOST_F_GOST_EC_VERIFY, GOST_R_SIGNATURE_MISMATCH);
421 * Computes GOST R 34.10-2001 public key
422 * or GOST R 34.10-2012 public key
425 int gost_ec_compute_public(EC_KEY *ec)
427 const EC_GROUP *group = (ec) ? EC_KEY_get0_group(ec) : NULL;
428 EC_POINT *pub_key = NULL;
429 const BIGNUM *priv_key = NULL;
434 GOSTerr(GOST_F_GOST_EC_COMPUTE_PUBLIC, GOST_R_KEY_IS_NOT_INITIALIZED);
440 GOSTerr(GOST_F_GOST_EC_COMPUTE_PUBLIC, ERR_R_MALLOC_FAILURE);
445 priv_key = EC_KEY_get0_private_key(ec);
447 GOSTerr(GOST_F_GOST_EC_COMPUTE_PUBLIC, ERR_R_EC_LIB);
451 pub_key = EC_POINT_new(group);
453 GOSTerr(GOST_F_GOST_EC_COMPUTE_PUBLIC, ERR_R_MALLOC_FAILURE);
457 if (!EC_POINT_mul(group, pub_key, priv_key, NULL, NULL, ctx)) {
458 GOSTerr(GOST_F_GOST_EC_COMPUTE_PUBLIC, ERR_R_EC_LIB);
461 if (!EC_KEY_set_public_key(ec, pub_key)) {
462 GOSTerr(GOST_F_GOST_EC_COMPUTE_PUBLIC, ERR_R_EC_LIB);
468 EC_POINT_free(pub_key);
476 * Generates GOST R 34.10-2001
477 * or GOST R 34.10-2012 keypair
480 int gost_ec_keygen(EC_KEY *ec)
482 BIGNUM *order = NULL, *d = NULL;
483 const EC_GROUP *group = (ec) ? EC_KEY_get0_group(ec) : NULL;
487 GOSTerr(GOST_F_GOST_EC_KEYGEN, ERR_R_INTERNAL_ERROR);
494 GOSTerr(GOST_F_GOST_EC_KEYGEN, ERR_R_MALLOC_FAILURE);
498 if (!EC_GROUP_get_order(group, order, NULL)) {
499 GOSTerr(GOST_F_GOST_EC_KEYGEN, ERR_R_INTERNAL_ERROR);
504 if (!BN_rand_range(d, order)) {
505 GOSTerr(GOST_F_GOST_EC_KEYGEN,
506 GOST_R_RANDOM_NUMBER_GENERATOR_FAILED);
510 while (BN_is_zero(d));
512 if (!EC_KEY_set_private_key(ec, d)) {
513 GOSTerr(GOST_F_GOST_EC_KEYGEN, ERR_R_INTERNAL_ERROR);
524 return (ok) ? gost_ec_compute_public(ec) : 0;