forked from gost-engine/engine
/
gost_ec_keyx.c
341 lines (318 loc) · 11.3 KB
/
gost_ec_keyx.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
/**********************************************************************
* gost_ec_keyx.c *
* Copyright (c) 2005-2013 Cryptocom LTD *
* This file is distributed under the same license as OpenSSL *
* *
* VK0 34.10-2001 key exchange and GOST R 34.10-2001 *
* based PKCS7/SMIME support *
* Requires OpenSSL 0.9.9 for compilation *
**********************************************************************/
#include <openssl/evp.h>
#include <openssl/err.h>
#include <openssl/rand.h>
#include <string.h>
#include <openssl/objects.h>
#include "gost89.h"
#include "e_gost_err.h"
#include "gost_keywrap.h"
#include "gost_lcl.h"
/* Implementation of CryptoPro VKO 34.10-2001/2012 algorithm */
static int VKO_compute_key(unsigned char *shared_key, size_t shared_key_size,
const EC_POINT *pub_key, EC_KEY *priv_key,
const unsigned char *ukm, int dgst_nid)
{
unsigned char *databuf = NULL, *hashbuf = NULL;
BIGNUM *UKM = NULL, *p = NULL, *order = NULL, *X = NULL, *Y = NULL;
const BIGNUM *key = EC_KEY_get0_private_key(priv_key);
EC_POINT *pnt = EC_POINT_new(EC_KEY_get0_group(priv_key));
int i;
BN_CTX *ctx = BN_CTX_new();
EVP_MD_CTX mdctx;
const EVP_MD *md;
int effective_dgst_nid = (dgst_nid == NID_id_GostR3411_2012_512) ?
NID_id_GostR3411_2012_256 : dgst_nid;
int buf_len = (dgst_nid == NID_id_GostR3411_2012_512) ? 128 : 64,
half_len = buf_len >> 1;
if (!ctx) {
GOSTerr(GOST_F_VKO_COMPUTE_KEY, ERR_R_MALLOC_FAILURE);
return 0;
}
BN_CTX_start(ctx);
databuf = OPENSSL_malloc(buf_len);
hashbuf = OPENSSL_malloc(buf_len);
if (!databuf || !hashbuf) {
GOSTerr(GOST_F_VKO_COMPUTE_KEY, ERR_R_MALLOC_FAILURE);
goto err;
}
md = EVP_get_digestbynid(effective_dgst_nid);
if (!md) {
GOSTerr(GOST_F_VKO_COMPUTE_KEY, GOST_R_INVALID_DIGEST_TYPE);
goto err;
}
UKM = hashsum2bn(ukm, 8);
p = BN_CTX_get(ctx);
order = BN_CTX_get(ctx);
X = BN_CTX_get(ctx);
Y = BN_CTX_get(ctx);
EC_GROUP_get_order(EC_KEY_get0_group(priv_key), order, ctx);
BN_mod_mul(p, key, UKM, order, ctx);
if (!EC_POINT_mul
(EC_KEY_get0_group(priv_key), pnt, NULL, pub_key, p, ctx)) {
GOSTerr(GOST_F_VKO_COMPUTE_KEY, GOST_R_ERROR_POINT_MUL);
goto err;
}
EC_POINT_get_affine_coordinates_GFp(EC_KEY_get0_group(priv_key),
pnt, X, Y, ctx);
/*
* Serialize elliptic curve point same way as we do it when saving key
*/
store_bignum(Y, databuf, half_len);
store_bignum(X, databuf + half_len, half_len);
/* And reverse byte order of whole buffer */
for (i = 0; i < buf_len; i++) {
hashbuf[buf_len - 1 - i] = databuf[i];
}
EVP_MD_CTX_init(&mdctx);
EVP_DigestInit_ex(&mdctx, md, NULL);
EVP_DigestUpdate(&mdctx, hashbuf, buf_len);
EVP_DigestFinal_ex(&mdctx, shared_key, NULL);
EVP_MD_CTX_cleanup(&mdctx);
err:
BN_free(UKM);
BN_CTX_end(ctx);
BN_CTX_free(ctx);
EC_POINT_free(pnt);
if (databuf)
OPENSSL_free(databuf);
if (hashbuf)
OPENSSL_free(hashbuf);
return 32;
}
/*
* EVP_PKEY_METHOD callback derive.
* Implements VKO R 34.10-2001/2012 algorithms
*/
int pkey_gost_ec_derive(EVP_PKEY_CTX *ctx, unsigned char *key, size_t *keylen)
{
/*
* Public key of peer in the ctx field peerkey
* Our private key in the ctx pkey
* ukm is in the algorithm specific context data
*/
EVP_PKEY *my_key = EVP_PKEY_CTX_get0_pkey(ctx);
EVP_PKEY *peer_key = EVP_PKEY_CTX_get0_peerkey(ctx);
struct gost_pmeth_data *data = EVP_PKEY_CTX_get_data(ctx);
int dgst_nid = NID_undef;
if (!data || !data->shared_ukm) {
GOSTerr(GOST_F_PKEY_GOST_EC_DERIVE, GOST_R_UKM_NOT_SET);
return 0;
}
if (key == NULL) {
*keylen = 32;
return 32;
}
EVP_PKEY_get_default_digest_nid(my_key, &dgst_nid);
*keylen =
VKO_compute_key(key, 32,
EC_KEY_get0_public_key(EVP_PKEY_get0(peer_key)),
(EC_KEY *)EVP_PKEY_get0(my_key), data->shared_ukm,
dgst_nid);
return (*keylen) ? 1 : 0;
}
/*
* EVP_PKEY_METHOD callback encrypt
* Implementation of GOST2001 key transport, cryptocom variation
*/
/*
* Generates ephemeral key based on pubk algorithm computes shared key using
* VKO and returns filled up GOST_KEY_TRANSPORT structure
*/
/*
* EVP_PKEY_METHOD callback encrypt
* Implementation of GOST2001 key transport, cryptopo variation
*/
int pkey_GOST_ECcp_encrypt(EVP_PKEY_CTX *pctx, unsigned char *out,
size_t *out_len, const unsigned char *key,
size_t key_len)
{
GOST_KEY_TRANSPORT *gkt = NULL;
EVP_PKEY *pubk = EVP_PKEY_CTX_get0_pkey(pctx);
struct gost_pmeth_data *data = EVP_PKEY_CTX_get_data(pctx);
int pkey_nid = EVP_PKEY_base_id(pubk);
ASN1_OBJECT *crypt_params_obj = (pkey_nid == NID_id_GostR3410_2001) ?
OBJ_nid2obj(NID_id_Gost28147_89_CryptoPro_A_ParamSet) :
OBJ_nid2obj(NID_id_tc26_gost_28147_param_Z);
const struct gost_cipher_info *param =
get_encryption_params(crypt_params_obj);
unsigned char ukm[8], shared_key[32], crypted_key[44];
int ret = 0;
int key_is_ephemeral = 1;
gost_ctx cctx;
EVP_PKEY *sec_key = EVP_PKEY_CTX_get0_peerkey(pctx);
if (data->shared_ukm) {
memcpy(ukm, data->shared_ukm, 8);
} else if (out) {
if (RAND_bytes(ukm, 8) <= 0) {
GOSTerr(GOST_F_PKEY_GOST_ECCP_ENCRYPT, GOST_R_RNG_ERROR);
return 0;
}
}
/* Check for private key in the peer_key of context */
if (sec_key) {
key_is_ephemeral = 0;
if (!gost_get0_priv_key(sec_key)) {
GOSTerr(GOST_F_PKEY_GOST_ECCP_ENCRYPT,
GOST_R_NO_PRIVATE_PART_OF_NON_EPHEMERAL_KEYPAIR);
goto err;
}
} else {
key_is_ephemeral = 1;
if (out) {
sec_key = EVP_PKEY_new();
EVP_PKEY_assign(sec_key, EVP_PKEY_base_id(pubk), EC_KEY_new());
EVP_PKEY_copy_parameters(sec_key, pubk);
if (!gost_ec_keygen(EVP_PKEY_get0(sec_key))) {
goto err;
}
}
}
if (!get_gost_engine_param(GOST_PARAM_CRYPT_PARAMS)
&& param == gost_cipher_list) {
param = gost_cipher_list;
}
if (out) {
int dgst_nid = NID_undef;
EVP_PKEY_get_default_digest_nid(pubk, &dgst_nid);
if (!VKO_compute_key(shared_key, 32,
EC_KEY_get0_public_key(EVP_PKEY_get0(pubk)),
EVP_PKEY_get0(sec_key), ukm, dgst_nid)) {
GOSTerr(GOST_F_PKEY_GOST_ECCP_ENCRYPT,
GOST_R_ERROR_COMPUTING_SHARED_KEY);
goto err;
}
gost_init(&cctx, param->sblock);
keyWrapCryptoPro(&cctx, shared_key, ukm, key, crypted_key);
}
gkt = GOST_KEY_TRANSPORT_new();
if (!gkt) {
goto err;
}
if (!ASN1_OCTET_STRING_set(gkt->key_agreement_info->eph_iv, ukm, 8)) {
goto err;
}
if (!ASN1_OCTET_STRING_set(gkt->key_info->imit, crypted_key + 40, 4)) {
goto err;
}
if (!ASN1_OCTET_STRING_set
(gkt->key_info->encrypted_key, crypted_key + 8, 32)) {
goto err;
}
if (key_is_ephemeral) {
if (!X509_PUBKEY_set
(&gkt->key_agreement_info->ephem_key, out ? sec_key : pubk)) {
GOSTerr(GOST_F_PKEY_GOST_ECCP_ENCRYPT,
GOST_R_CANNOT_PACK_EPHEMERAL_KEY);
goto err;
}
}
ASN1_OBJECT_free(gkt->key_agreement_info->cipher);
gkt->key_agreement_info->cipher = OBJ_nid2obj(param->nid);
if (key_is_ephemeral)
EVP_PKEY_free(sec_key);
if (!key_is_ephemeral) {
/* Set control "public key from client certificate used" */
if (EVP_PKEY_CTX_ctrl(pctx, -1, -1, EVP_PKEY_CTRL_PEER_KEY, 3, NULL)
<= 0) {
GOSTerr(GOST_F_PKEY_GOST_ECCP_ENCRYPT, GOST_R_CTRL_CALL_FAILED);
goto err;
}
}
if ((*out_len = i2d_GOST_KEY_TRANSPORT(gkt, out ? &out : NULL)) > 0)
ret = 1;
GOST_KEY_TRANSPORT_free(gkt);
return ret;
err:
if (key_is_ephemeral)
EVP_PKEY_free(sec_key);
GOST_KEY_TRANSPORT_free(gkt);
return -1;
}
/*
* EVP_PKEY_METHOD callback decrypt
* Implementation of GOST2001 key transport, cryptopo variation
*/
int pkey_GOST_ECcp_decrypt(EVP_PKEY_CTX *pctx, unsigned char *key,
size_t *key_len, const unsigned char *in,
size_t in_len)
{
const unsigned char *p = in;
EVP_PKEY *priv = EVP_PKEY_CTX_get0_pkey(pctx);
GOST_KEY_TRANSPORT *gkt = NULL;
int ret = 0;
unsigned char wrappedKey[44];
unsigned char sharedKey[32];
gost_ctx ctx;
const struct gost_cipher_info *param = NULL;
EVP_PKEY *eph_key = NULL, *peerkey = NULL;
int dgst_nid = NID_undef;
if (!key) {
*key_len = 32;
return 1;
}
gkt = d2i_GOST_KEY_TRANSPORT(NULL, (const unsigned char **)&p, in_len);
if (!gkt) {
GOSTerr(GOST_F_PKEY_GOST_ECCP_DECRYPT,
GOST_R_ERROR_PARSING_KEY_TRANSPORT_INFO);
return -1;
}
/* If key transport structure contains public key, use it */
eph_key = X509_PUBKEY_get(gkt->key_agreement_info->ephem_key);
if (eph_key) {
if (EVP_PKEY_derive_set_peer(pctx, eph_key) <= 0) {
GOSTerr(GOST_F_PKEY_GOST_ECCP_DECRYPT,
GOST_R_INCOMPATIBLE_PEER_KEY);
goto err;
}
} else {
/* Set control "public key from client certificate used" */
if (EVP_PKEY_CTX_ctrl(pctx, -1, -1, EVP_PKEY_CTRL_PEER_KEY, 3, NULL)
<= 0) {
GOSTerr(GOST_F_PKEY_GOST_ECCP_DECRYPT, GOST_R_CTRL_CALL_FAILED);
goto err;
}
}
peerkey = EVP_PKEY_CTX_get0_peerkey(pctx);
if (!peerkey) {
GOSTerr(GOST_F_PKEY_GOST_ECCP_DECRYPT, GOST_R_NO_PEER_KEY);
goto err;
}
param = get_encryption_params(gkt->key_agreement_info->cipher);
if (!param) {
goto err;
}
gost_init(&ctx, param->sblock);
OPENSSL_assert(gkt->key_agreement_info->eph_iv->length == 8);
memcpy(wrappedKey, gkt->key_agreement_info->eph_iv->data, 8);
OPENSSL_assert(gkt->key_info->encrypted_key->length == 32);
memcpy(wrappedKey + 8, gkt->key_info->encrypted_key->data, 32);
OPENSSL_assert(gkt->key_info->imit->length == 4);
memcpy(wrappedKey + 40, gkt->key_info->imit->data, 4);
EVP_PKEY_get_default_digest_nid(priv, &dgst_nid);
if (!VKO_compute_key(sharedKey, 32,
EC_KEY_get0_public_key(EVP_PKEY_get0(peerkey)),
EVP_PKEY_get0(priv), wrappedKey, dgst_nid)) {
GOSTerr(GOST_F_PKEY_GOST_ECCP_DECRYPT,
GOST_R_ERROR_COMPUTING_SHARED_KEY);
goto err;
}
if (!keyUnwrapCryptoPro(&ctx, sharedKey, wrappedKey, key)) {
GOSTerr(GOST_F_PKEY_GOST_ECCP_DECRYPT,
GOST_R_ERROR_COMPUTING_SHARED_KEY);
goto err;
}
ret = 1;
err:
EVP_PKEY_free(eph_key);
GOST_KEY_TRANSPORT_free(gkt);
return ret;
}