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/err.h>
12 #include <openssl/rand.h>
14 #include <openssl/objects.h>
16 #include "e_gost_err.h"
17 #include "gost_keywrap.h"
20 /* Implementation of CryptoPro VKO 34.10-2001/2012 algorithm */
21 static int VKO_compute_key(unsigned char *shared_key, size_t shared_key_size,
22 const EC_POINT *pub_key, EC_KEY *priv_key,
23 const unsigned char *ukm, int dgst_nid)
25 unsigned char *databuf = NULL;
26 BIGNUM *UKM = NULL, *p = NULL, *order = NULL, *X = NULL, *Y = NULL;
27 const BIGNUM *key = EC_KEY_get0_private_key(priv_key);
28 EC_POINT *pnt = EC_POINT_new(EC_KEY_get0_group(priv_key));
30 BN_CTX *ctx = BN_CTX_new();
31 EVP_MD_CTX *mdctx = NULL;
32 const EVP_MD *md = NULL;
33 int effective_dgst_nid = (dgst_nid == NID_id_GostR3411_2012_512) ?
34 NID_id_GostR3411_2012_256 : dgst_nid;
35 int buf_len = (dgst_nid == NID_id_GostR3411_2012_512) ? 128 : 64,
36 half_len = buf_len >> 1;
40 GOSTerr(GOST_F_VKO_COMPUTE_KEY, ERR_R_MALLOC_FAILURE);
45 databuf = OPENSSL_zalloc(buf_len);
47 GOSTerr(GOST_F_VKO_COMPUTE_KEY, ERR_R_MALLOC_FAILURE);
51 md = EVP_get_digestbynid(effective_dgst_nid);
53 GOSTerr(GOST_F_VKO_COMPUTE_KEY, GOST_R_INVALID_DIGEST_TYPE);
57 UKM = hashsum2bn(ukm, 8);
59 order = BN_CTX_get(ctx);
62 EC_GROUP_get_order(EC_KEY_get0_group(priv_key), order, ctx);
63 BN_mod_mul(p, key, UKM, order, ctx);
65 (EC_KEY_get0_group(priv_key), pnt, NULL, pub_key, p, ctx)) {
66 GOSTerr(GOST_F_VKO_COMPUTE_KEY, GOST_R_ERROR_POINT_MUL);
69 EC_POINT_get_affine_coordinates_GFp(EC_KEY_get0_group(priv_key),
72 * Serialize elliptic curve point same way as we do it when saving key
74 store_bignum(Y, databuf, half_len);
75 store_bignum(X, databuf + half_len, half_len);
76 /* And reverse byte order of whole buffer */
77 BUF_reverse(databuf, NULL, buf_len);
79 mdctx = EVP_MD_CTX_new();
81 GOSTerr(GOST_F_VKO_COMPUTE_KEY, ERR_R_MALLOC_FAILURE);
84 EVP_MD_CTX_init(mdctx);
85 EVP_DigestInit_ex(mdctx, md, NULL);
86 EVP_DigestUpdate(mdctx, databuf, buf_len);
87 EVP_DigestFinal_ex(mdctx, shared_key, NULL);
97 EVP_MD_CTX_free(mdctx);
99 OPENSSL_free(databuf);
105 * EVP_PKEY_METHOD callback derive.
106 * Implements VKO R 34.10-2001/2012 algorithms
108 int pkey_gost_ec_derive(EVP_PKEY_CTX *ctx, unsigned char *key, size_t *keylen)
111 * Public key of peer in the ctx field peerkey
112 * Our private key in the ctx pkey
113 * ukm is in the algorithm specific context data
115 EVP_PKEY *my_key = EVP_PKEY_CTX_get0_pkey(ctx);
116 EVP_PKEY *peer_key = EVP_PKEY_CTX_get0_peerkey(ctx);
117 struct gost_pmeth_data *data = EVP_PKEY_CTX_get_data(ctx);
118 int dgst_nid = NID_undef;
120 if (!data || !data->shared_ukm) {
121 GOSTerr(GOST_F_PKEY_GOST_EC_DERIVE, GOST_R_UKM_NOT_SET);
130 EVP_PKEY_get_default_digest_nid(my_key, &dgst_nid);
133 VKO_compute_key(key, 32,
134 EC_KEY_get0_public_key(EVP_PKEY_get0(peer_key)),
135 (EC_KEY *)EVP_PKEY_get0(my_key), data->shared_ukm,
137 return (*keylen) ? 1 : 0;
141 * Generates ephemeral key based on pubk algorithm computes shared key using
142 * VKO and returns filled up GOST_KEY_TRANSPORT structure
146 * EVP_PKEY_METHOD callback encrypt
147 * Implementation of GOST2001 key transport, cryptopo variation
150 int pkey_GOST_ECcp_encrypt(EVP_PKEY_CTX *pctx, unsigned char *out,
151 size_t *out_len, const unsigned char *key,
154 GOST_KEY_TRANSPORT *gkt = NULL;
155 EVP_PKEY *pubk = EVP_PKEY_CTX_get0_pkey(pctx);
156 struct gost_pmeth_data *data = EVP_PKEY_CTX_get_data(pctx);
157 int pkey_nid = EVP_PKEY_base_id(pubk);
158 ASN1_OBJECT *crypt_params_obj = (pkey_nid == NID_id_GostR3410_2001) ?
159 OBJ_nid2obj(NID_id_Gost28147_89_CryptoPro_A_ParamSet) :
160 OBJ_nid2obj(NID_id_tc26_gost_28147_param_Z);
161 const struct gost_cipher_info *param =
162 get_encryption_params(crypt_params_obj);
163 unsigned char ukm[8], shared_key[32], crypted_key[44];
165 int key_is_ephemeral = 1;
167 EVP_PKEY *sec_key = EVP_PKEY_CTX_get0_peerkey(pctx);
168 if (data->shared_ukm) {
169 memcpy(ukm, data->shared_ukm, 8);
172 if (RAND_bytes(ukm, 8) <= 0) {
173 GOSTerr(GOST_F_PKEY_GOST_ECCP_ENCRYPT, GOST_R_RNG_ERROR);
177 /* Check for private key in the peer_key of context */
179 key_is_ephemeral = 0;
180 if (!gost_get0_priv_key(sec_key)) {
181 GOSTerr(GOST_F_PKEY_GOST_ECCP_ENCRYPT,
182 GOST_R_NO_PRIVATE_PART_OF_NON_EPHEMERAL_KEYPAIR);
186 key_is_ephemeral = 1;
188 sec_key = EVP_PKEY_new();
189 if (! EVP_PKEY_assign(sec_key, EVP_PKEY_base_id(pubk), EC_KEY_new()) ||
190 ! EVP_PKEY_copy_parameters(sec_key, pubk) ||
191 ! gost_ec_keygen(EVP_PKEY_get0(sec_key))) {
192 GOSTerr(GOST_F_PKEY_GOST_ECCP_ENCRYPT,
193 GOST_R_ERROR_COMPUTING_SHARED_KEY);
198 if (!get_gost_engine_param(GOST_PARAM_CRYPT_PARAMS)
199 && param == gost_cipher_list) {
200 param = gost_cipher_list;
203 int dgst_nid = NID_undef;
204 EVP_PKEY_get_default_digest_nid(pubk, &dgst_nid);
206 if (!VKO_compute_key(shared_key, 32,
207 EC_KEY_get0_public_key(EVP_PKEY_get0(pubk)),
208 EVP_PKEY_get0(sec_key), ukm, dgst_nid)) {
209 GOSTerr(GOST_F_PKEY_GOST_ECCP_ENCRYPT,
210 GOST_R_ERROR_COMPUTING_SHARED_KEY);
213 gost_init(&cctx, param->sblock);
214 keyWrapCryptoPro(&cctx, shared_key, ukm, key, crypted_key);
216 gkt = GOST_KEY_TRANSPORT_new();
220 if (!ASN1_OCTET_STRING_set(gkt->key_agreement_info->eph_iv, ukm, 8)) {
223 if (!ASN1_OCTET_STRING_set(gkt->key_info->imit, crypted_key + 40, 4)) {
226 if (!ASN1_OCTET_STRING_set
227 (gkt->key_info->encrypted_key, crypted_key + 8, 32)) {
230 if (key_is_ephemeral) {
232 (&gkt->key_agreement_info->ephem_key, out ? sec_key : pubk)) {
233 GOSTerr(GOST_F_PKEY_GOST_ECCP_ENCRYPT,
234 GOST_R_CANNOT_PACK_EPHEMERAL_KEY);
238 ASN1_OBJECT_free(gkt->key_agreement_info->cipher);
239 gkt->key_agreement_info->cipher = OBJ_nid2obj(param->nid);
240 if (key_is_ephemeral)
241 EVP_PKEY_free(sec_key);
242 if (!key_is_ephemeral) {
243 /* Set control "public key from client certificate used" */
244 if (EVP_PKEY_CTX_ctrl(pctx, -1, -1, EVP_PKEY_CTRL_PEER_KEY, 3, NULL)
246 GOSTerr(GOST_F_PKEY_GOST_ECCP_ENCRYPT, GOST_R_CTRL_CALL_FAILED);
250 if ((*out_len = i2d_GOST_KEY_TRANSPORT(gkt, out ? &out : NULL)) > 0)
252 GOST_KEY_TRANSPORT_free(gkt);
255 if (key_is_ephemeral)
256 EVP_PKEY_free(sec_key);
257 GOST_KEY_TRANSPORT_free(gkt);
262 * EVP_PKEY_METHOD callback decrypt
263 * Implementation of GOST2001 key transport, cryptopo variation
265 int pkey_GOST_ECcp_decrypt(EVP_PKEY_CTX *pctx, unsigned char *key,
266 size_t *key_len, const unsigned char *in,
269 const unsigned char *p = in;
270 EVP_PKEY *priv = EVP_PKEY_CTX_get0_pkey(pctx);
271 GOST_KEY_TRANSPORT *gkt = NULL;
273 unsigned char wrappedKey[44];
274 unsigned char sharedKey[32];
276 const struct gost_cipher_info *param = NULL;
277 EVP_PKEY *eph_key = NULL, *peerkey = NULL;
278 int dgst_nid = NID_undef;
284 gkt = d2i_GOST_KEY_TRANSPORT(NULL, (const unsigned char **)&p, in_len);
286 GOSTerr(GOST_F_PKEY_GOST_ECCP_DECRYPT,
287 GOST_R_ERROR_PARSING_KEY_TRANSPORT_INFO);
291 /* If key transport structure contains public key, use it */
292 eph_key = X509_PUBKEY_get(gkt->key_agreement_info->ephem_key);
294 if (EVP_PKEY_derive_set_peer(pctx, eph_key) <= 0) {
295 GOSTerr(GOST_F_PKEY_GOST_ECCP_DECRYPT,
296 GOST_R_INCOMPATIBLE_PEER_KEY);
300 /* Set control "public key from client certificate used" */
301 if (EVP_PKEY_CTX_ctrl(pctx, -1, -1, EVP_PKEY_CTRL_PEER_KEY, 3, NULL)
303 GOSTerr(GOST_F_PKEY_GOST_ECCP_DECRYPT, GOST_R_CTRL_CALL_FAILED);
307 peerkey = EVP_PKEY_CTX_get0_peerkey(pctx);
309 GOSTerr(GOST_F_PKEY_GOST_ECCP_DECRYPT, GOST_R_NO_PEER_KEY);
313 param = get_encryption_params(gkt->key_agreement_info->cipher);
318 gost_init(&ctx, param->sblock);
319 OPENSSL_assert(gkt->key_agreement_info->eph_iv->length == 8);
320 memcpy(wrappedKey, gkt->key_agreement_info->eph_iv->data, 8);
321 OPENSSL_assert(gkt->key_info->encrypted_key->length == 32);
322 memcpy(wrappedKey + 8, gkt->key_info->encrypted_key->data, 32);
323 OPENSSL_assert(gkt->key_info->imit->length == 4);
324 memcpy(wrappedKey + 40, gkt->key_info->imit->data, 4);
326 EVP_PKEY_get_default_digest_nid(priv, &dgst_nid);
327 if (!VKO_compute_key(sharedKey, 32,
328 EC_KEY_get0_public_key(EVP_PKEY_get0(peerkey)),
329 EVP_PKEY_get0(priv), wrappedKey, dgst_nid)) {
330 GOSTerr(GOST_F_PKEY_GOST_ECCP_DECRYPT,
331 GOST_R_ERROR_COMPUTING_SHARED_KEY);
334 if (!keyUnwrapCryptoPro(&ctx, sharedKey, wrappedKey, key)) {
335 GOSTerr(GOST_F_PKEY_GOST_ECCP_DECRYPT,
336 GOST_R_ERROR_COMPUTING_SHARED_KEY);
342 EVP_PKEY_free(eph_key);
343 GOST_KEY_TRANSPORT_free(gkt);