1 /**********************************************************************
3 * Copyright (c) 2005-2006 Cryptocom LTD *
4 * This file is distributed under the same license as OpenSSL *
6 * Implements generation and parsing of GOST_KEY_TRANSPORT for *
7 * GOST R 34.10-94 algorithms *
9 * Requires OpenSSL 0.9.9 for compilation *
10 **********************************************************************/
12 #include <openssl/dh.h>
13 #include <openssl/rand.h>
14 #include <openssl/err.h>
15 #include <openssl/evp.h>
16 #include <openssl/objects.h>
20 #include "e_gost_err.h"
21 #include "gost_keywrap.h"
23 /* Common functions for both 94 and 2001 key exchange schemes */
25 * Implementation of the Diffi-Hellman key agreement scheme based on GOST-94
30 * Computes Diffie-Hellman key and stores it into buffer in little-endian
31 * byte order as expected by both versions of GOST 94 algorithm
33 static int compute_pair_key_le(unsigned char *pair_key, BIGNUM *pub_key,
36 unsigned char be_key[128];
38 key_size = DH_compute_key(be_key, pub_key, dh);
41 memset(pair_key, 0, 128);
42 for (i = 0; i < key_size; i++) {
43 pair_key[i] = be_key[key_size - 1 - i];
49 * Computes 256 bit Key exchange key as specified in RFC 4357
51 static int make_cp_exchange_key(BIGNUM *priv_key, EVP_PKEY *pubk,
52 unsigned char *shared_key)
54 unsigned char dh_key[128];
56 gost_hash_ctx hash_ctx;
61 memset(dh_key, 0, 128);
62 dh->g = BN_dup(pubk->pkey.dsa->g);
63 dh->p = BN_dup(pubk->pkey.dsa->p);
64 dh->priv_key = BN_dup(priv_key);
66 compute_pair_key_le(dh_key, ((DSA *)(EVP_PKEY_get0(pubk)))->pub_key,
71 init_gost_hash_ctx(&hash_ctx, &GostR3411_94_CryptoProParamSet);
72 start_hash(&hash_ctx);
73 hash_block(&hash_ctx, dh_key, 128);
74 finish_hash(&hash_ctx, shared_key);
75 done_gost_hash_ctx(&hash_ctx);
79 /* EVP_PKEY_METHOD callback derive. Implements VKO R 34.10-94 */
81 int pkey_gost94_derive(EVP_PKEY_CTX *ctx, unsigned char *key, size_t *keylen)
83 EVP_PKEY *pubk = EVP_PKEY_CTX_get0_peerkey(ctx);
84 EVP_PKEY *mykey = EVP_PKEY_CTX_get0_pkey(ctx);
89 return make_cp_exchange_key(gost_get0_priv_key(mykey), pubk, key);
93 * EVP_PKEY_METHOD callback encrypt for GOST R 34.10-94 cryptopro
97 int pkey_GOST94cp_encrypt(EVP_PKEY_CTX *ctx, unsigned char *out,
98 size_t *outlen, const unsigned char *key,
101 GOST_KEY_TRANSPORT *gkt = NULL;
102 unsigned char shared_key[32], ukm[8], crypted_key[44];
103 const struct gost_cipher_info *param = get_encryption_params(NULL);
104 EVP_PKEY *pubk = EVP_PKEY_CTX_get0_pkey(ctx);
105 struct gost_pmeth_data *data = EVP_PKEY_CTX_get_data(ctx);
107 int key_is_ephemeral = 1;
109 EVP_PKEY *mykey = EVP_PKEY_CTX_get0_peerkey(ctx);
111 /* Do not use vizir cipher parameters with cryptopro */
112 if (!get_gost_engine_param(GOST_PARAM_CRYPT_PARAMS)
113 && param == gost_cipher_list) {
114 param = gost_cipher_list + 1;
118 /* If key already set, it is not ephemeral */
119 key_is_ephemeral = 0;
120 if (!gost_get0_priv_key(mykey)) {
121 GOSTerr(GOST_F_PKEY_GOST94CP_ENCRYPT,
122 GOST_R_NO_PRIVATE_PART_OF_NON_EPHEMERAL_KEYPAIR);
126 /* Otherwise generate ephemeral key */
127 key_is_ephemeral = 1;
129 mykey = EVP_PKEY_new();
130 EVP_PKEY_assign(mykey, EVP_PKEY_base_id(pubk), DSA_new());
131 EVP_PKEY_copy_parameters(mykey, pubk);
132 if (!gost_sign_keygen(EVP_PKEY_get0(mykey))) {
138 make_cp_exchange_key(gost_get0_priv_key(mykey), pubk, shared_key);
139 if (data->shared_ukm) {
140 memcpy(ukm, data->shared_ukm, 8);
142 if (RAND_bytes(ukm, 8) <= 0) {
143 GOSTerr(GOST_F_PKEY_GOST94CP_ENCRYPT,
144 GOST_R_RANDOM_GENERATOR_FAILURE);
150 gost_init(&cctx, param->sblock);
151 keyWrapCryptoPro(&cctx, shared_key, ukm, key, crypted_key);
153 gkt = GOST_KEY_TRANSPORT_new();
157 if (!ASN1_OCTET_STRING_set(gkt->key_agreement_info->eph_iv, ukm, 8)) {
160 if (!ASN1_OCTET_STRING_set(gkt->key_info->imit, crypted_key + 40, 4)) {
163 if (!ASN1_OCTET_STRING_set
164 (gkt->key_info->encrypted_key, crypted_key + 8, 32)) {
167 if (key_is_ephemeral) {
169 (&gkt->key_agreement_info->ephem_key, out ? mykey : pubk)) {
170 GOSTerr(GOST_F_PKEY_GOST94CP_ENCRYPT,
171 GOST_R_CANNOT_PACK_EPHEMERAL_KEY);
175 EVP_PKEY_free(mykey);
177 ASN1_OBJECT_free(gkt->key_agreement_info->cipher);
178 gkt->key_agreement_info->cipher = OBJ_nid2obj(param->nid);
179 tmp_outlen = i2d_GOST_KEY_TRANSPORT(gkt, out ? &out : NULL);
180 if (tmp_outlen <= 0) {
181 GOSTerr(GOST_F_PKEY_GOST94CP_ENCRYPT,
182 GOST_R_ERROR_PACKING_KEY_TRANSPORT_INFO);
185 *outlen = tmp_outlen;
186 if (!key_is_ephemeral) {
187 /* Set control "public key from client certificate used" */
188 if (EVP_PKEY_CTX_ctrl(ctx, -1, -1, EVP_PKEY_CTRL_PEER_KEY, 3, NULL) <=
190 GOSTerr(GOST_F_PKEY_GOST94CP_ENCRYPT, GOST_R_CTRL_CALL_FAILED);
194 GOST_KEY_TRANSPORT_free(gkt);
197 if (key_is_ephemeral) {
198 EVP_PKEY_free(mykey);
200 GOSTerr(GOST_F_PKEY_GOST94CP_ENCRYPT, ERR_R_MALLOC_FAILURE);
202 GOST_KEY_TRANSPORT_free(gkt);
207 * EVP_PLEY_METHOD callback decrypt for GOST R 34.10-94 cryptopro
210 int pkey_GOST94cp_decrypt(EVP_PKEY_CTX *ctx, unsigned char *key,
211 size_t *key_len, const unsigned char *in,
214 const unsigned char *p = in;
215 GOST_KEY_TRANSPORT *gkt = NULL;
216 unsigned char wrappedKey[44];
217 unsigned char sharedKey[32];
219 const struct gost_cipher_info *param = NULL;
220 EVP_PKEY *eph_key = NULL, *peerkey = NULL;
221 EVP_PKEY *priv = EVP_PKEY_CTX_get0_pkey(ctx);
228 gkt = d2i_GOST_KEY_TRANSPORT(NULL, (const unsigned char **)&p, in_len);
230 GOSTerr(GOST_F_PKEY_GOST94CP_DECRYPT,
231 GOST_R_ERROR_PARSING_KEY_TRANSPORT_INFO);
234 eph_key = X509_PUBKEY_get(gkt->key_agreement_info->ephem_key);
236 if (EVP_PKEY_derive_set_peer(ctx, eph_key) <= 0) {
237 GOSTerr(GOST_F_PKEY_GOST94CP_DECRYPT,
238 GOST_R_INCOMPATIBLE_PEER_KEY);
242 /* Set control "public key from client certificate used" */
243 if (EVP_PKEY_CTX_ctrl(ctx, -1, -1, EVP_PKEY_CTRL_PEER_KEY, 3, NULL) <=
245 GOSTerr(GOST_F_PKEY_GOST94CP_DECRYPT, GOST_R_CTRL_CALL_FAILED);
249 peerkey = EVP_PKEY_CTX_get0_peerkey(ctx);
251 GOSTerr(GOST_F_PKEY_GOST94CP_DECRYPT, GOST_R_NO_PEER_KEY);
255 param = get_encryption_params(gkt->key_agreement_info->cipher);
260 gost_init(&cctx, param->sblock);
261 OPENSSL_assert(gkt->key_agreement_info->eph_iv->length == 8);
262 memcpy(wrappedKey, gkt->key_agreement_info->eph_iv->data, 8);
263 OPENSSL_assert(gkt->key_info->encrypted_key->length == 32);
264 memcpy(wrappedKey + 8, gkt->key_info->encrypted_key->data, 32);
265 OPENSSL_assert(gkt->key_info->imit->length == 4);
266 memcpy(wrappedKey + 40, gkt->key_info->imit->data, 4);
267 make_cp_exchange_key(gost_get0_priv_key(priv), peerkey, sharedKey);
268 if (!keyUnwrapCryptoPro(&cctx, sharedKey, wrappedKey, key)) {
269 GOSTerr(GOST_F_PKEY_GOST94CP_DECRYPT,
270 GOST_R_ERROR_COMPUTING_SHARED_KEY);
274 EVP_PKEY_free(eph_key);
275 GOST_KEY_TRANSPORT_free(gkt);
278 EVP_PKEY_free(eph_key);
279 GOST_KEY_TRANSPORT_free(gkt);