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 int VKO_compute_key(unsigned char *shared_key,
22 const EC_POINT *pub_key, const EC_KEY *priv_key,
23 const unsigned char *ukm, const size_t ukm_size,
24 const int vko_dgst_nid)
26 unsigned char *databuf = NULL;
27 BIGNUM *UKM = NULL, *p = NULL, *order = NULL, *X = NULL, *Y = NULL, *cofactor = NULL;
28 const BIGNUM *key = EC_KEY_get0_private_key(priv_key);
29 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 buf_len, half_len;
37 GOSTerr(GOST_F_VKO_COMPUTE_KEY, ERR_R_MALLOC_FAILURE);
42 md = EVP_get_digestbynid(vko_dgst_nid);
44 GOSTerr(GOST_F_VKO_COMPUTE_KEY, GOST_R_INVALID_DIGEST_TYPE);
48 UKM = hashsum2bn(ukm, ukm_size);
50 order = BN_CTX_get(ctx);
51 cofactor = BN_CTX_get(ctx);
54 EC_GROUP_get_order(EC_KEY_get0_group(priv_key), order, ctx);
55 EC_GROUP_get_cofactor(EC_KEY_get0_group(priv_key), cofactor, ctx);
56 BN_mod_mul(UKM, UKM, cofactor, order, ctx);
57 BN_mod_mul(p, key, UKM, order, ctx);
58 if (!EC_POINT_mul(EC_KEY_get0_group(priv_key), pnt, NULL, pub_key, p, ctx)) {
59 GOSTerr(GOST_F_VKO_COMPUTE_KEY, GOST_R_ERROR_POINT_MUL);
62 EC_POINT_get_affine_coordinates(EC_KEY_get0_group(priv_key),
65 half_len = BN_num_bytes(order);
66 buf_len = 2 * half_len;
67 databuf = OPENSSL_zalloc(buf_len);
69 GOSTerr(GOST_F_VKO_COMPUTE_KEY, ERR_R_MALLOC_FAILURE);
74 * Serialize elliptic curve point same way as we do it when saving key
76 store_bignum(Y, databuf, half_len);
77 store_bignum(X, databuf + half_len, half_len);
78 /* And reverse byte order of whole buffer */
79 BUF_reverse(databuf, NULL, buf_len);
81 mdctx = EVP_MD_CTX_new();
83 GOSTerr(GOST_F_VKO_COMPUTE_KEY, ERR_R_MALLOC_FAILURE);
86 EVP_MD_CTX_init(mdctx);
87 EVP_DigestInit_ex(mdctx, md, NULL);
88 EVP_DigestUpdate(mdctx, databuf, buf_len);
89 EVP_DigestFinal_ex(mdctx, shared_key, NULL);
90 ret = (EVP_MD_size(md) > 0) ? EVP_MD_size(md) : 0;
99 EVP_MD_CTX_free(mdctx);
101 OPENSSL_free(databuf);
107 * keyout expected to be 64 bytes
109 static int gost_keg(const unsigned char *ukm_source, int pkey_nid,
110 const EC_POINT *pub_key, const EC_KEY *priv_key,
111 unsigned char *keyout)
114 unsigned char real_ukm[16];
117 memset(real_ukm, 0, 16);
118 if (memcmp(ukm_source, real_ukm, 16) == 0)
121 memcpy(real_ukm, ukm_source, 16);
122 BUF_reverse(real_ukm, NULL, 16);
126 case NID_id_GostR3410_2012_512:
128 VKO_compute_key(keyout, pub_key, priv_key, real_ukm, 16,
129 NID_id_GostR3411_2012_512);
130 return (keylen) ? keylen : 0;
133 case NID_id_GostR3410_2012_256:
135 unsigned char tmpkey[32];
137 VKO_compute_key(tmpkey, pub_key, priv_key, real_ukm, 16,
138 NID_id_GostR3411_2012_256);
143 if (gost_kdftree2012_256
144 (keyout, 64, tmpkey, 32, (const unsigned char *)"kdf tree", 8,
145 ukm_source + 16, 8, 1) > 0)
150 OPENSSL_cleanse(tmpkey, 32);
151 return (keylen) ? keylen : 0;
160 * EVP_PKEY_METHOD callback derive.
161 * Implements VKO R 34.10-2001/2012 algorithms
163 int pkey_gost_ec_derive(EVP_PKEY_CTX *ctx, unsigned char *key, size_t *keylen)
166 * Public key of peer in the ctx field peerkey
167 * Our private key in the ctx pkey
168 * ukm is in the algorithm specific context data
170 EVP_PKEY *my_key = EVP_PKEY_CTX_get0_pkey(ctx);
171 EVP_PKEY *peer_key = EVP_PKEY_CTX_get0_peerkey(ctx);
172 struct gost_pmeth_data *data = EVP_PKEY_CTX_get_data(ctx);
173 int dgst_nid = NID_undef;
175 if (!data || !data->shared_ukm) {
176 GOSTerr(GOST_F_PKEY_GOST_EC_DERIVE, GOST_R_UKM_NOT_SET);
180 * shared_ukm_size = 8 stands for pre-2018 cipher suites
181 * It means 32 bytes of key length, 8 byte UKM, 32-bytes hash
183 * shared_ukm_size = 32 stands for pre-2018 cipher suites
184 * It means 64 bytes of shared_key, 16 bytes of UKM and either
185 * 64 bytes of hash or 64 bytes of TLSTREE output
188 switch (data->shared_ukm_size) {
196 EVP_PKEY_get_default_digest_nid(my_key, &dgst_nid);
197 if (dgst_nid == NID_id_GostR3411_2012_512)
198 dgst_nid = NID_id_GostR3411_2012_256;
202 EC_KEY_get0_public_key(EVP_PKEY_get0(peer_key)),
203 (EC_KEY *)EVP_PKEY_get0(my_key),
204 data->shared_ukm, 8, dgst_nid);
205 return (*keylen) ? 1 : 0;
215 *keylen = gost_keg(data->shared_ukm, EVP_PKEY_id(my_key),
216 EC_KEY_get0_public_key(EVP_PKEY_get0(peer_key)),
217 (EC_KEY *)EVP_PKEY_get0(my_key), key);
218 return (*keylen) ? 1 : 0;
228 * Generates ephemeral key based on pubk algorithm computes shared key using
229 * VKO and returns filled up GOST_KEY_TRANSPORT structure
233 * EVP_PKEY_METHOD callback encrypt
234 * Implementation of GOST2001/12 key transport, cryptopro variation
237 static int pkey_GOST_ECcp_encrypt(EVP_PKEY_CTX *pctx, unsigned char *out,
238 size_t *out_len, const unsigned char *key,
241 GOST_KEY_TRANSPORT *gkt = NULL;
242 EVP_PKEY *pubk = EVP_PKEY_CTX_get0_pkey(pctx);
243 struct gost_pmeth_data *data = EVP_PKEY_CTX_get_data(pctx);
244 int pkey_nid = EVP_PKEY_base_id(pubk);
245 ASN1_OBJECT *crypt_params_obj = (pkey_nid == NID_id_GostR3410_2001) ?
246 OBJ_nid2obj(NID_id_Gost28147_89_CryptoPro_A_ParamSet) :
247 OBJ_nid2obj(NID_id_tc26_gost_28147_param_Z);
248 const struct gost_cipher_info *param =
249 get_encryption_params(crypt_params_obj);
250 unsigned char ukm[8], shared_key[32], crypted_key[44];
252 int key_is_ephemeral = 1;
254 EVP_PKEY *sec_key = EVP_PKEY_CTX_get0_peerkey(pctx);
255 if (data->shared_ukm) {
256 memcpy(ukm, data->shared_ukm, 8);
258 if (RAND_bytes(ukm, 8) <= 0) {
259 GOSTerr(GOST_F_PKEY_GOST_ECCP_ENCRYPT, GOST_R_RNG_ERROR);
263 /* Check for private key in the peer_key of context */
265 key_is_ephemeral = 0;
266 if (!gost_get0_priv_key(sec_key)) {
267 GOSTerr(GOST_F_PKEY_GOST_ECCP_ENCRYPT,
268 GOST_R_NO_PRIVATE_PART_OF_NON_EPHEMERAL_KEYPAIR);
272 key_is_ephemeral = 1;
274 sec_key = EVP_PKEY_new();
275 if (!EVP_PKEY_assign(sec_key, EVP_PKEY_base_id(pubk), EC_KEY_new())
276 || !EVP_PKEY_copy_parameters(sec_key, pubk)
277 || !gost_ec_keygen(EVP_PKEY_get0(sec_key))) {
278 GOSTerr(GOST_F_PKEY_GOST_ECCP_ENCRYPT,
279 GOST_R_ERROR_COMPUTING_SHARED_KEY);
284 if (!get_gost_engine_param(GOST_PARAM_CRYPT_PARAMS)
285 && param == gost_cipher_list) {
286 param = gost_cipher_list;
289 int dgst_nid = NID_undef;
290 EVP_PKEY_get_default_digest_nid(pubk, &dgst_nid);
291 if (dgst_nid == NID_id_GostR3411_2012_512)
292 dgst_nid = NID_id_GostR3411_2012_256;
294 if (!VKO_compute_key(shared_key,
295 EC_KEY_get0_public_key(EVP_PKEY_get0(pubk)),
296 EVP_PKEY_get0(sec_key), ukm, 8, dgst_nid)) {
297 GOSTerr(GOST_F_PKEY_GOST_ECCP_ENCRYPT,
298 GOST_R_ERROR_COMPUTING_SHARED_KEY);
301 gost_init(&cctx, param->sblock);
302 keyWrapCryptoPro(&cctx, shared_key, ukm, key, crypted_key);
304 gkt = GOST_KEY_TRANSPORT_new();
308 if (!ASN1_OCTET_STRING_set(gkt->key_agreement_info->eph_iv, ukm, 8)) {
311 if (!ASN1_OCTET_STRING_set(gkt->key_info->imit, crypted_key + 40, 4)) {
314 if (!ASN1_OCTET_STRING_set
315 (gkt->key_info->encrypted_key, crypted_key + 8, 32)) {
318 if (key_is_ephemeral) {
320 (&gkt->key_agreement_info->ephem_key, out ? sec_key : pubk)) {
321 GOSTerr(GOST_F_PKEY_GOST_ECCP_ENCRYPT,
322 GOST_R_CANNOT_PACK_EPHEMERAL_KEY);
326 ASN1_OBJECT_free(gkt->key_agreement_info->cipher);
327 gkt->key_agreement_info->cipher = OBJ_nid2obj(param->nid);
328 if (key_is_ephemeral)
329 EVP_PKEY_free(sec_key);
330 if (!key_is_ephemeral) {
331 /* Set control "public key from client certificate used" */
332 if (EVP_PKEY_CTX_ctrl(pctx, -1, -1, EVP_PKEY_CTRL_PEER_KEY, 3, NULL)
334 GOSTerr(GOST_F_PKEY_GOST_ECCP_ENCRYPT, GOST_R_CTRL_CALL_FAILED);
338 if ((*out_len = i2d_GOST_KEY_TRANSPORT(gkt, out ? &out : NULL)) > 0)
340 GOST_KEY_TRANSPORT_free(gkt);
343 if (key_is_ephemeral)
344 EVP_PKEY_free(sec_key);
345 GOST_KEY_TRANSPORT_free(gkt);
350 * EVP_PKEY_METHOD callback decrypt
351 * Implementation of GOST2018 key transport
353 static int pkey_gost2018_encrypt(EVP_PKEY_CTX *pctx, unsigned char *out,
354 size_t *out_len, const unsigned char *key,
357 PSKeyTransport_gost *pst = NULL;
358 EVP_PKEY *pubk = EVP_PKEY_CTX_get0_pkey(pctx);
359 struct gost_pmeth_data *data = EVP_PKEY_CTX_get_data(pctx);
360 int pkey_nid = EVP_PKEY_base_id(pubk);
361 unsigned char expkeys[64];
362 EVP_PKEY *sec_key = NULL;
364 int mac_nid = NID_undef;
366 int exp_len = 0, iv_len = 0;
367 unsigned char *exp_buf = NULL;
368 int key_is_ephemeral = 0;
370 switch (data->cipher_nid) {
372 mac_nid = NID_magma_mac;
376 case NID_grasshopper_ctr:
377 mac_nid = NID_grasshopper_mac;
382 GOSTerr(GOST_F_PKEY_GOST2018_ENCRYPT, GOST_R_INVALID_CIPHER);
386 exp_len = key_len + mac_len;
387 exp_buf = OPENSSL_malloc(exp_len);
389 GOSTerr(GOST_F_PKEY_GOST2018_ENCRYPT, ERR_R_MALLOC_FAILURE);
393 sec_key = EVP_PKEY_CTX_get0_peerkey(pctx);
396 sec_key = EVP_PKEY_new();
397 if (sec_key == NULL) {
398 GOSTerr(GOST_F_PKEY_GOST2018_ENCRYPT, ERR_R_MALLOC_FAILURE );
402 if (!EVP_PKEY_assign(sec_key, EVP_PKEY_base_id(pubk), EC_KEY_new())
403 || !EVP_PKEY_copy_parameters(sec_key, pubk)
404 || !gost_ec_keygen(EVP_PKEY_get0(sec_key))) {
405 GOSTerr(GOST_F_PKEY_GOST2018_ENCRYPT,
406 GOST_R_ERROR_COMPUTING_SHARED_KEY);
409 key_is_ephemeral = 1;
412 if (gost_keg(data->shared_ukm, pkey_nid,
413 EC_KEY_get0_public_key(EVP_PKEY_get0(pubk)),
414 EVP_PKEY_get0(sec_key), expkeys) <= 0) {
415 GOSTerr(GOST_F_PKEY_GOST2018_ENCRYPT,
416 GOST_R_ERROR_COMPUTING_EXPORT_KEYS);
420 if (gost_kexp15(key, key_len, data->cipher_nid, expkeys + 32,
421 mac_nid, expkeys + 0, data->shared_ukm + 24, iv_len,
422 exp_buf, &exp_len) <= 0) {
423 GOSTerr(GOST_F_PKEY_GOST2018_ENCRYPT, GOST_R_CANNOT_PACK_EPHEMERAL_KEY);
427 pst = PSKeyTransport_gost_new();
429 GOSTerr(GOST_F_PKEY_GOST2018_ENCRYPT, ERR_R_MALLOC_FAILURE);
433 if (!ASN1_OCTET_STRING_set(pst->psexp, exp_buf, exp_len)) {
434 GOSTerr(GOST_F_PKEY_GOST2018_ENCRYPT, ERR_R_MALLOC_FAILURE);
438 if (!X509_PUBKEY_set(&pst->ephem_key, out ? sec_key : pubk)) {
439 GOSTerr(GOST_F_PKEY_GOST2018_ENCRYPT, GOST_R_CANNOT_PACK_EPHEMERAL_KEY);
443 if ((*out_len = i2d_PSKeyTransport_gost(pst, out ? &out : NULL)) > 0)
446 if (key_is_ephemeral)
447 EVP_PKEY_free(sec_key);
449 PSKeyTransport_gost_free(pst);
450 OPENSSL_free(exp_buf);
454 int pkey_gost_encrypt(EVP_PKEY_CTX *pctx, unsigned char *out,
455 size_t *out_len, const unsigned char *key, size_t key_len)
457 struct gost_pmeth_data *data = EVP_PKEY_CTX_get_data(pctx);
458 if (data->shared_ukm == NULL || data->shared_ukm_size == 8)
459 return pkey_GOST_ECcp_encrypt(pctx, out, out_len, key, key_len);
460 else if (data->shared_ukm_size == 32)
461 return pkey_gost2018_encrypt(pctx, out, out_len, key, key_len);
463 GOSTerr(GOST_F_PKEY_GOST_ENCRYPT, ERR_R_INTERNAL_ERROR);
469 * EVP_PKEY_METHOD callback decrypt
470 * Implementation of GOST2001/12 key transport, cryptopro variation
472 static int pkey_GOST_ECcp_decrypt(EVP_PKEY_CTX *pctx, unsigned char *key,
473 size_t *key_len, const unsigned char *in,
476 const unsigned char *p = in;
477 EVP_PKEY *priv = EVP_PKEY_CTX_get0_pkey(pctx);
478 GOST_KEY_TRANSPORT *gkt = NULL;
480 unsigned char wrappedKey[44];
481 unsigned char sharedKey[32];
483 const struct gost_cipher_info *param = NULL;
484 EVP_PKEY *eph_key = NULL, *peerkey = NULL;
485 int dgst_nid = NID_undef;
491 gkt = d2i_GOST_KEY_TRANSPORT(NULL, (const unsigned char **)&p, in_len);
493 GOSTerr(GOST_F_PKEY_GOST_ECCP_DECRYPT,
494 GOST_R_ERROR_PARSING_KEY_TRANSPORT_INFO);
498 /* If key transport structure contains public key, use it */
499 eph_key = X509_PUBKEY_get(gkt->key_agreement_info->ephem_key);
501 if (EVP_PKEY_derive_set_peer(pctx, eph_key) <= 0) {
502 GOSTerr(GOST_F_PKEY_GOST_ECCP_DECRYPT,
503 GOST_R_INCOMPATIBLE_PEER_KEY);
507 /* Set control "public key from client certificate used" */
508 if (EVP_PKEY_CTX_ctrl(pctx, -1, -1, EVP_PKEY_CTRL_PEER_KEY, 3, NULL)
510 GOSTerr(GOST_F_PKEY_GOST_ECCP_DECRYPT, GOST_R_CTRL_CALL_FAILED);
514 peerkey = EVP_PKEY_CTX_get0_peerkey(pctx);
516 GOSTerr(GOST_F_PKEY_GOST_ECCP_DECRYPT, GOST_R_NO_PEER_KEY);
520 param = get_encryption_params(gkt->key_agreement_info->cipher);
525 gost_init(&ctx, param->sblock);
526 OPENSSL_assert(gkt->key_agreement_info->eph_iv->length == 8);
527 memcpy(wrappedKey, gkt->key_agreement_info->eph_iv->data, 8);
528 OPENSSL_assert(gkt->key_info->encrypted_key->length == 32);
529 memcpy(wrappedKey + 8, gkt->key_info->encrypted_key->data, 32);
530 OPENSSL_assert(gkt->key_info->imit->length == 4);
531 memcpy(wrappedKey + 40, gkt->key_info->imit->data, 4);
533 EVP_PKEY_get_default_digest_nid(priv, &dgst_nid);
534 if (dgst_nid == NID_id_GostR3411_2012_512)
535 dgst_nid = NID_id_GostR3411_2012_256;
537 if (!VKO_compute_key(sharedKey,
538 EC_KEY_get0_public_key(EVP_PKEY_get0(peerkey)),
539 EVP_PKEY_get0(priv), wrappedKey, 8, dgst_nid)) {
540 GOSTerr(GOST_F_PKEY_GOST_ECCP_DECRYPT,
541 GOST_R_ERROR_COMPUTING_SHARED_KEY);
544 if (!keyUnwrapCryptoPro(&ctx, sharedKey, wrappedKey, key)) {
545 GOSTerr(GOST_F_PKEY_GOST_ECCP_DECRYPT,
546 GOST_R_ERROR_COMPUTING_SHARED_KEY);
552 EVP_PKEY_free(eph_key);
553 GOST_KEY_TRANSPORT_free(gkt);
558 * EVP_PKEY_METHOD callback decrypt
559 * Implementation of GOST2018 key transport
561 static int pkey_gost2018_decrypt(EVP_PKEY_CTX *pctx, unsigned char *key,
562 size_t *key_len, const unsigned char *in,
565 const unsigned char *p = in;
566 struct gost_pmeth_data *data = EVP_PKEY_CTX_get_data(pctx);
567 EVP_PKEY *priv = EVP_PKEY_CTX_get0_pkey(pctx);
568 PSKeyTransport_gost *pst = NULL;
570 unsigned char expkeys[64];
571 EVP_PKEY *eph_key = NULL;
572 int pkey_nid = EVP_PKEY_base_id(priv);
573 int mac_nid = NID_undef;
576 switch (data->cipher_nid) {
578 mac_nid = NID_magma_mac;
581 case NID_grasshopper_ctr:
582 mac_nid = NID_grasshopper_mac;
586 GOSTerr(GOST_F_PKEY_GOST2018_DECRYPT, GOST_R_INVALID_CIPHER);
595 pst = d2i_PSKeyTransport_gost(NULL, (const unsigned char **)&p, in_len);
597 GOSTerr(GOST_F_PKEY_GOST2018_DECRYPT,
598 GOST_R_ERROR_PARSING_KEY_TRANSPORT_INFO);
602 eph_key = X509_PUBKEY_get(pst->ephem_key);
605 1. Checks the next three conditions fulfilling and terminates the
606 connection with fatal error if not.
608 o Q_eph is on the same curve as server public key;
610 o Q_eph is not equal to zero point;
612 o q * Q_eph is not equal to zero point.
614 if (gost_keg(data->shared_ukm, pkey_nid,
615 EC_KEY_get0_public_key(EVP_PKEY_get0(eph_key)),
616 EVP_PKEY_get0(priv), expkeys) <= 0) {
617 GOSTerr(GOST_F_PKEY_GOST2018_DECRYPT,
618 GOST_R_ERROR_COMPUTING_EXPORT_KEYS);
622 if (gost_kimp15(ASN1_STRING_get0_data(pst->psexp),
623 ASN1_STRING_length(pst->psexp), data->cipher_nid,
624 expkeys + 32, mac_nid, expkeys + 0, data->shared_ukm + 24,
626 GOSTerr(GOST_F_PKEY_GOST2018_DECRYPT, GOST_R_CANNOT_UNPACK_EPHEMERAL_KEY);
632 EVP_PKEY_free(eph_key);
633 PSKeyTransport_gost_free(pst);
637 int pkey_gost_decrypt(EVP_PKEY_CTX *pctx, unsigned char *key,
638 size_t *key_len, const unsigned char *in, size_t in_len)
640 struct gost_pmeth_data *data = EVP_PKEY_CTX_get_data(pctx);
641 if (data->shared_ukm == NULL || data->shared_ukm_size == 8)
642 return pkey_GOST_ECcp_decrypt(pctx, key, key_len, in, in_len);
643 else if (data->shared_ukm_size == 32)
644 return pkey_gost2018_decrypt(pctx, key, key_len, in, in_len);
646 GOSTerr(GOST_F_PKEY_GOST_DECRYPT, ERR_R_INTERNAL_ERROR);