1 /**********************************************************************
3 * Copyright (c) 2005-2013 Cryptocom LTD *
4 * This file is distributed under the same license as OpenSSL *
6 * VK0 34.10-2001 key exchange and GOST R 34.10-2001 *
7 * based PKCS7/SMIME support *
8 * Requires OpenSSL 0.9.9 for compilation *
9 **********************************************************************/
10 #include <openssl/evp.h>
11 #include <openssl/rand.h>
13 #include <openssl/objects.h>
15 #include "e_gost_err.h"
16 #include "gost_keywrap.h"
19 /* Implementation of CryptoPro VKO 34.10-2001/2012 algorithm */
20 static int VKO_compute_key(unsigned char *shared_key, size_t shared_key_size,
21 const EC_POINT *pub_key, EC_KEY *priv_key,
22 const unsigned char *ukm, int dgst_nid)
24 unsigned char *databuf = NULL, *hashbuf = NULL;
25 BIGNUM *UKM = NULL, *p = NULL, *order = NULL, *X = NULL, *Y = NULL;
26 const BIGNUM *key = EC_KEY_get0_private_key(priv_key);
27 EC_POINT *pnt = EC_POINT_new(EC_KEY_get0_group(priv_key));
29 BN_CTX *ctx = BN_CTX_new();
32 int effective_dgst_nid = (dgst_nid == NID_id_GostR3411_2012_512) ?
33 NID_id_GostR3411_2012_256 : dgst_nid;
34 int buf_len = (dgst_nid == NID_id_GostR3411_2012_512) ? 128 : 64,
35 half_len = buf_len >> 1;
38 GOSTerr(GOST_F_VKO_COMPUTE_KEY, ERR_R_MALLOC_FAILURE);
43 databuf = OPENSSL_malloc(buf_len);
44 hashbuf = OPENSSL_malloc(buf_len);
45 if (!databuf || !hashbuf) {
46 GOSTerr(GOST_F_VKO_COMPUTE_KEY, ERR_R_MALLOC_FAILURE);
50 md = EVP_get_digestbynid(effective_dgst_nid);
52 GOSTerr(GOST_F_VKO_COMPUTE_KEY, GOST_R_INVALID_DIGEST_TYPE);
56 UKM = hashsum2bn(ukm, 8);
58 order = BN_CTX_get(ctx);
61 EC_GROUP_get_order(EC_KEY_get0_group(priv_key), order, ctx);
62 BN_mod_mul(p, key, UKM, order, ctx);
63 if(!EC_POINT_mul(EC_KEY_get0_group(priv_key), pnt, NULL, pub_key, p, ctx)) {
64 GOSTerr(GOST_F_VKO_COMPUTE_KEY, GOST_R_ERROR_POINT_MUL);
67 EC_POINT_get_affine_coordinates_GFp(EC_KEY_get0_group(priv_key),
70 * Serialize elliptic curve point same way as we do it when saving key
72 store_bignum(Y, databuf, half_len);
73 store_bignum(X, databuf + half_len, half_len);
74 /* And reverse byte order of whole buffer */
75 for (i = 0; i < buf_len; i++) {
76 hashbuf[buf_len - 1 - i] = databuf[i];
78 EVP_MD_CTX_init(&mdctx);
79 EVP_DigestInit_ex(&mdctx, md, NULL);
80 EVP_DigestUpdate(&mdctx, hashbuf, buf_len);
81 EVP_DigestFinal_ex(&mdctx, shared_key, NULL);
82 EVP_MD_CTX_cleanup(&mdctx);
89 OPENSSL_free(databuf);
91 OPENSSL_free(hashbuf);
97 * EVP_PKEY_METHOD callback derive.
98 * Implements VKO R 34.10-2001/2012 algorithms
100 int pkey_gost_ec_derive(EVP_PKEY_CTX *ctx, unsigned char *key, size_t *keylen)
103 * Public key of peer in the ctx field peerkey
104 * Our private key in the ctx pkey
105 * ukm is in the algorithm specific context data
107 EVP_PKEY *my_key = EVP_PKEY_CTX_get0_pkey(ctx);
108 EVP_PKEY *peer_key = EVP_PKEY_CTX_get0_peerkey(ctx);
109 struct gost_pmeth_data *data = EVP_PKEY_CTX_get_data(ctx);
110 int dgst_nid = NID_undef;
112 if (!data || !data->shared_ukm) {
113 GOSTerr(GOST_F_PKEY_GOST_EC_DERIVE, GOST_R_UKM_NOT_SET);
122 EVP_PKEY_get_default_digest_nid(my_key, &dgst_nid);
125 VKO_compute_key(key, 32,
126 EC_KEY_get0_public_key(EVP_PKEY_get0(peer_key)),
127 (EC_KEY *)EVP_PKEY_get0(my_key), data->shared_ukm,
129 return (*keylen) ? 1 : 0;
133 * EVP_PKEY_METHOD callback encrypt
134 * Implementation of GOST2001 key transport, cryptocom variation
137 * Generates ephemeral key based on pubk algorithm computes shared key using
138 * VKO and returns filled up GOST_KEY_TRANSPORT structure
142 * EVP_PKEY_METHOD callback encrypt
143 * Implementation of GOST2001 key transport, cryptopo variation
146 int pkey_GOST_ECcp_encrypt(EVP_PKEY_CTX *pctx, unsigned char *out,
147 size_t *out_len, const unsigned char *key,
150 GOST_KEY_TRANSPORT *gkt = NULL;
151 EVP_PKEY *pubk = EVP_PKEY_CTX_get0_pkey(pctx);
152 struct gost_pmeth_data *data = EVP_PKEY_CTX_get_data(pctx);
153 int pkey_nid = EVP_PKEY_base_id(pubk);
154 ASN1_OBJECT *crypt_params_obj = (pkey_nid == NID_id_GostR3410_2001) ?
155 OBJ_nid2obj(NID_id_Gost28147_89_CryptoPro_A_ParamSet) :
156 OBJ_nid2obj(NID_id_tc26_gost_28147_param_Z);
157 const struct gost_cipher_info *param =
158 get_encryption_params(crypt_params_obj);
159 unsigned char ukm[8], shared_key[32], crypted_key[44];
161 int key_is_ephemeral = 1;
163 EVP_PKEY *sec_key = EVP_PKEY_CTX_get0_peerkey(pctx);
164 if (data->shared_ukm) {
165 memcpy(ukm, data->shared_ukm, 8);
168 if (RAND_bytes(ukm, 8) <= 0) {
169 GOSTerr(GOST_F_PKEY_GOST_ECCP_ENCRYPT, GOST_R_RNG_ERROR);
173 /* Check for private key in the peer_key of context */
175 key_is_ephemeral = 0;
176 if (!gost_get0_priv_key(sec_key)) {
177 GOSTerr(GOST_F_PKEY_GOST_ECCP_ENCRYPT,
178 GOST_R_NO_PRIVATE_PART_OF_NON_EPHEMERAL_KEYPAIR);
182 key_is_ephemeral = 1;
184 sec_key = EVP_PKEY_new();
185 EVP_PKEY_assign(sec_key, EVP_PKEY_base_id(pubk), EC_KEY_new());
186 EVP_PKEY_copy_parameters(sec_key, pubk);
187 if (!gost_ec_keygen(EVP_PKEY_get0(sec_key))) {
192 if (!get_gost_engine_param(GOST_PARAM_CRYPT_PARAMS)
193 && param == gost_cipher_list) {
194 param = gost_cipher_list;
197 int dgst_nid = NID_undef;
198 EVP_PKEY_get_default_digest_nid(pubk, &dgst_nid);
200 if (!VKO_compute_key(shared_key, 32,
201 EC_KEY_get0_public_key(EVP_PKEY_get0(pubk)),
202 EVP_PKEY_get0(sec_key), ukm, dgst_nid)) {
203 GOSTerr(GOST_F_PKEY_GOST_ECCP_ENCRYPT,
204 GOST_R_ERROR_COMPUTING_SHARED_KEY);
207 gost_init(&cctx, param->sblock);
208 keyWrapCryptoPro(&cctx, shared_key, ukm, key, crypted_key);
210 gkt = GOST_KEY_TRANSPORT_new();
214 if (!ASN1_OCTET_STRING_set(gkt->key_agreement_info->eph_iv, ukm, 8)) {
217 if (!ASN1_OCTET_STRING_set(gkt->key_info->imit, crypted_key + 40, 4)) {
220 if (!ASN1_OCTET_STRING_set
221 (gkt->key_info->encrypted_key, crypted_key + 8, 32)) {
224 if (key_is_ephemeral) {
226 (&gkt->key_agreement_info->ephem_key, out ? sec_key : pubk)) {
227 GOSTerr(GOST_F_PKEY_GOST_ECCP_ENCRYPT,
228 GOST_R_CANNOT_PACK_EPHEMERAL_KEY);
232 ASN1_OBJECT_free(gkt->key_agreement_info->cipher);
233 gkt->key_agreement_info->cipher = OBJ_nid2obj(param->nid);
234 if (key_is_ephemeral)
235 EVP_PKEY_free(sec_key);
236 if (!key_is_ephemeral) {
237 /* Set control "public key from client certificate used" */
238 if (EVP_PKEY_CTX_ctrl(pctx, -1, -1, EVP_PKEY_CTRL_PEER_KEY, 3, NULL)
240 GOSTerr(GOST_F_PKEY_GOST_ECCP_ENCRYPT, GOST_R_CTRL_CALL_FAILED);
244 if ((*out_len = i2d_GOST_KEY_TRANSPORT(gkt, out ? &out : NULL)) > 0)
246 GOST_KEY_TRANSPORT_free(gkt);
249 if (key_is_ephemeral)
250 EVP_PKEY_free(sec_key);
251 GOST_KEY_TRANSPORT_free(gkt);
256 * EVP_PKEY_METHOD callback decrypt
257 * Implementation of GOST2001 key transport, cryptopo variation
259 int pkey_GOST_ECcp_decrypt(EVP_PKEY_CTX *pctx, unsigned char *key,
260 size_t *key_len, const unsigned char *in,
263 const unsigned char *p = in;
264 EVP_PKEY *priv = EVP_PKEY_CTX_get0_pkey(pctx);
265 GOST_KEY_TRANSPORT *gkt = NULL;
267 unsigned char wrappedKey[44];
268 unsigned char sharedKey[32];
270 const struct gost_cipher_info *param = NULL;
271 EVP_PKEY *eph_key = NULL, *peerkey = NULL;
272 int dgst_nid = NID_undef;
278 gkt = d2i_GOST_KEY_TRANSPORT(NULL, (const unsigned char **)&p, in_len);
280 GOSTerr(GOST_F_PKEY_GOST_ECCP_DECRYPT,
281 GOST_R_ERROR_PARSING_KEY_TRANSPORT_INFO);
285 /* If key transport structure contains public key, use it */
286 eph_key = X509_PUBKEY_get(gkt->key_agreement_info->ephem_key);
288 if (EVP_PKEY_derive_set_peer(pctx, eph_key) <= 0) {
289 GOSTerr(GOST_F_PKEY_GOST_ECCP_DECRYPT,
290 GOST_R_INCOMPATIBLE_PEER_KEY);
294 /* Set control "public key from client certificate used" */
295 if (EVP_PKEY_CTX_ctrl(pctx, -1, -1, EVP_PKEY_CTRL_PEER_KEY, 3, NULL)
297 GOSTerr(GOST_F_PKEY_GOST_ECCP_DECRYPT, GOST_R_CTRL_CALL_FAILED);
301 peerkey = EVP_PKEY_CTX_get0_peerkey(pctx);
303 GOSTerr(GOST_F_PKEY_GOST_ECCP_DECRYPT, GOST_R_NO_PEER_KEY);
307 param = get_encryption_params(gkt->key_agreement_info->cipher);
312 gost_init(&ctx, param->sblock);
313 OPENSSL_assert(gkt->key_agreement_info->eph_iv->length == 8);
314 memcpy(wrappedKey, gkt->key_agreement_info->eph_iv->data, 8);
315 OPENSSL_assert(gkt->key_info->encrypted_key->length == 32);
316 memcpy(wrappedKey + 8, gkt->key_info->encrypted_key->data, 32);
317 OPENSSL_assert(gkt->key_info->imit->length == 4);
318 memcpy(wrappedKey + 40, gkt->key_info->imit->data, 4);
320 EVP_PKEY_get_default_digest_nid(priv, &dgst_nid);
321 if (!VKO_compute_key(sharedKey, 32,
322 EC_KEY_get0_public_key(EVP_PKEY_get0(peerkey)),
323 EVP_PKEY_get0(priv), wrappedKey, dgst_nid)) {
324 GOSTerr(GOST_F_PKEY_GOST_ECCP_DECRYPT,
325 GOST_R_ERROR_COMPUTING_SHARED_KEY);
328 if (!keyUnwrapCryptoPro(&ctx, sharedKey, wrappedKey, key)) {
329 GOSTerr(GOST_F_PKEY_GOST_ECCP_DECRYPT,
330 GOST_R_ERROR_COMPUTING_SHARED_KEY);
336 EVP_PKEY_free(eph_key);
337 GOST_KEY_TRANSPORT_free(gkt);