1 /**********************************************************************
3 * Copyright (c) 2005-2006 Cryptocom LTD *
4 * This file is distributed under the same license as OpenSSL *
6 * Implementation of GOST R 34.10-2001 *
7 * Requires OpenSSL 0.9.9 for compilation *
8 **********************************************************************/
10 #include "gost_params.h"
12 #include <openssl/rand.h>
13 #include <openssl/ecdsa.h>
14 #include <openssl/err.h>
15 #include "e_gost_err.h"
18 void dump_signature(const char *message, const unsigned char *buffer,
20 void dump_dsa_sig(const char *message, DSA_SIG *sig);
23 # define dump_signature(a,b,c)
24 # define dump_dsa_sig(a,b)
28 * Fills EC_KEY structure hidden in the app_data field of DSA structure
29 * with parameter information, extracted from parameter array in
32 * Also fils DSA->q field with copy of EC_GROUP order field to make
33 * DSA_size function work
35 int fill_GOST2001_params(EC_KEY *eckey, int nid)
37 R3410_2001_params *params = R3410_2001_paramset;
39 BIGNUM *p = NULL, *q = NULL, *a = NULL, *b = NULL, *x = NULL, *y = NULL;
41 BN_CTX *ctx = BN_CTX_new();
51 while (params->nid != NID_undef && params->nid != nid)
53 if (params->nid == NID_undef) {
54 GOSTerr(GOST_F_FILL_GOST2001_PARAMS,
55 GOST_R_UNSUPPORTED_PARAMETER_SET);
58 BN_hex2bn(&p, params->p);
59 BN_hex2bn(&a, params->a);
60 BN_hex2bn(&b, params->b);
62 grp = EC_GROUP_new_curve_GFp(p, a, b, ctx);
64 P = EC_POINT_new(grp);
66 BN_hex2bn(&x, params->x);
67 BN_hex2bn(&y, params->y);
68 EC_POINT_set_affine_coordinates_GFp(grp, P, x, y, ctx);
69 BN_hex2bn(&q, params->q);
71 fprintf(stderr, "Set params index %d oid %s\nq=",
72 (params - R3410_2001_paramset), OBJ_nid2sn(params->nid));
73 BN_print_fp(stderr, q);
74 fprintf(stderr, "\n");
77 EC_GROUP_set_generator(grp, P, q, NULL);
78 EC_GROUP_set_curve_name(grp, params->nid);
80 EC_KEY_set_group(eckey, grp);
91 * Computes gost2001 signature as DSA_SIG structure
95 DSA_SIG *gost2001_do_sign(const unsigned char *dgst, int dlen, EC_KEY *eckey)
97 DSA_SIG *newsig = NULL;
98 BIGNUM *md = hashsum2bn(dgst);
100 const EC_GROUP *group;
101 const BIGNUM *priv_key;
102 BIGNUM *r = NULL, *s = NULL, *X = NULL, *tmp = NULL, *tmp2 = NULL, *k =
105 BN_CTX *ctx = BN_CTX_new();
107 OPENSSL_assert(dlen == 32);
108 newsig = DSA_SIG_new();
110 GOSTerr(GOST_F_GOST2001_DO_SIGN, GOST_R_NO_MEMORY);
113 group = EC_KEY_get0_group(eckey);
114 order = BN_CTX_get(ctx);
115 EC_GROUP_get_order(group, order, ctx);
116 priv_key = EC_KEY_get0_private_key(eckey);
118 BN_mod(e, md, order, ctx);
120 fprintf(stderr, "digest as bignum=");
121 BN_print_fp(stderr, md);
122 fprintf(stderr, "\ndigest mod q=");
123 BN_print_fp(stderr, e);
124 fprintf(stderr, "\n");
130 C = EC_POINT_new(group);
133 if (!BN_rand_range(k, order)) {
134 GOSTerr(GOST_F_GOST2001_DO_SIGN,
135 GOST_R_RANDOM_NUMBER_GENERATOR_FAILED);
136 DSA_SIG_free(newsig);
140 if (!EC_POINT_mul(group, C, k, NULL, NULL, ctx)) {
141 GOSTerr(GOST_F_GOST2001_DO_SIGN, ERR_R_EC_LIB);
142 DSA_SIG_free(newsig);
148 if (!EC_POINT_get_affine_coordinates_GFp(group, C, X, NULL, ctx)) {
149 GOSTerr(GOST_F_GOST2001_DO_SIGN, ERR_R_EC_LIB);
150 DSA_SIG_free(newsig);
156 BN_nnmod(r, X, order, ctx);
158 while (BN_is_zero(r));
159 /* s = (r*priv_key+k*e) mod order */
161 tmp = BN_CTX_get(ctx);
162 BN_mod_mul(tmp, priv_key, r, order, ctx);
164 tmp2 = BN_CTX_get(ctx);
165 BN_mod_mul(tmp2, k, e, order, ctx);
168 BN_mod_add(s, tmp, tmp2, order, ctx);
170 while (BN_is_zero(s));
172 newsig->s = BN_dup(s);
173 newsig->r = BN_dup(r);
183 * Verifies gost 2001 signature
186 int gost2001_do_verify(const unsigned char *dgst, int dgst_len,
187 DSA_SIG *sig, EC_KEY *ec)
189 BN_CTX *ctx = BN_CTX_new();
190 const EC_GROUP *group = EC_KEY_get0_group(ec);
192 BIGNUM *md = NULL, *e = NULL, *R = NULL, *v = NULL, *z1 = NULL, *z2 =
194 BIGNUM *X = NULL, *tmp = NULL;
196 const EC_POINT *pub_key = NULL;
200 order = BN_CTX_get(ctx);
202 z1 = BN_CTX_get(ctx);
203 z2 = BN_CTX_get(ctx);
204 tmp = BN_CTX_get(ctx);
209 EC_GROUP_get_order(group, order, ctx);
210 pub_key = EC_KEY_get0_public_key(ec);
211 if (BN_is_zero(sig->s) || BN_is_zero(sig->r) ||
212 (BN_cmp(sig->s, order) >= 1) || (BN_cmp(sig->r, order) >= 1)) {
213 GOSTerr(GOST_F_GOST2001_DO_VERIFY,
214 GOST_R_SIGNATURE_PARTS_GREATER_THAN_Q);
218 md = hashsum2bn(dgst);
220 BN_mod(e, md, order, ctx);
222 fprintf(stderr, "digest as bignum: ");
223 BN_print_fp(stderr, md);
224 fprintf(stderr, "\ndigest mod q: ");
225 BN_print_fp(stderr, e);
229 v = BN_mod_inverse(v, e, order, ctx);
230 BN_mod_mul(z1, sig->s, v, order, ctx);
231 BN_sub(tmp, order, sig->r);
232 BN_mod_mul(z2, tmp, v, order, ctx);
234 fprintf(stderr, "\nInverted digest value: ");
235 BN_print_fp(stderr, v);
236 fprintf(stderr, "\nz1: ");
237 BN_print_fp(stderr, z1);
238 fprintf(stderr, "\nz2: ");
239 BN_print_fp(stderr, z2);
241 C = EC_POINT_new(group);
242 if (!EC_POINT_mul(group, C, z1, pub_key, z2, ctx)) {
243 GOSTerr(GOST_F_GOST2001_DO_VERIFY, ERR_R_EC_LIB);
246 if (!EC_POINT_get_affine_coordinates_GFp(group, C, X, NULL, ctx)) {
247 GOSTerr(GOST_F_GOST2001_DO_VERIFY, ERR_R_EC_LIB);
250 BN_mod(R, X, order, ctx);
252 fprintf(stderr, "\nX=");
253 BN_print_fp(stderr, X);
254 fprintf(stderr, "\nX mod q=");
255 BN_print_fp(stderr, R);
256 fprintf(stderr, "\n");
258 if (BN_cmp(R, sig->r) != 0) {
259 GOSTerr(GOST_F_GOST2001_DO_VERIFY, GOST_R_SIGNATURE_MISMATCH);
272 * Computes GOST R 34.10-2001 public key
276 int gost2001_compute_public(EC_KEY *ec)
278 const EC_GROUP *group = EC_KEY_get0_group(ec);
279 EC_POINT *pub_key = NULL;
280 const BIGNUM *priv_key = NULL;
285 GOSTerr(GOST_F_GOST2001_COMPUTE_PUBLIC,
286 GOST_R_KEY_IS_NOT_INITIALIZED);
291 if (!(priv_key = EC_KEY_get0_private_key(ec))) {
292 GOSTerr(GOST_F_GOST2001_COMPUTE_PUBLIC, ERR_R_EC_LIB);
296 pub_key = EC_POINT_new(group);
297 if (!EC_POINT_mul(group, pub_key, priv_key, NULL, NULL, ctx)) {
298 GOSTerr(GOST_F_GOST2001_COMPUTE_PUBLIC, ERR_R_EC_LIB);
301 if (!EC_KEY_set_public_key(ec, pub_key)) {
302 GOSTerr(GOST_F_GOST2001_COMPUTE_PUBLIC, ERR_R_EC_LIB);
308 EC_POINT_free(pub_key);
315 * Generates GOST R 34.10-2001 keypair
319 int gost2001_keygen(EC_KEY *ec)
321 BIGNUM *order = BN_new(), *d = BN_new();
322 const EC_GROUP *group = EC_KEY_get0_group(ec);
323 EC_GROUP_get_order(group, order, NULL);
326 if (!BN_rand_range(d, order)) {
327 GOSTerr(GOST_F_GOST2001_KEYGEN,
328 GOST_R_RANDOM_NUMBER_GENERATOR_FAILED);
334 while (BN_is_zero(d));
335 EC_KEY_set_private_key(ec, d);
338 return gost2001_compute_public(ec);