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/evp.h>
15 #include <openssl/objects.h>
19 #include "e_gost_err.h"
20 #include "gost_keywrap.h"
22 /* Common functions for both 94 and 2001 key exchange schemes */
23 /* Implementation of the Diffi-Hellman key agreement scheme based on
26 /* Computes Diffie-Hellman key and stores it into buffer in
27 * little-endian byte order as expected by both versions of GOST 94
30 static int compute_pair_key_le(unsigned char *pair_key,BIGNUM *pub_key,DH *dh)
32 unsigned char be_key[128];
34 key_size=DH_compute_key(be_key,pub_key,dh);
35 if (!key_size) return 0;
36 memset(pair_key,0,128);
37 for (i=0;i<key_size;i++)
39 pair_key[i]=be_key[key_size-1-i];
45 * Computes 256 bit Key exchange key as specified in RFC 4357
47 static int make_cp_exchange_key(BIGNUM *priv_key,EVP_PKEY *pubk, unsigned char *shared_key)
49 unsigned char dh_key [128];
51 gost_hash_ctx hash_ctx;
57 dh->g = BN_dup(pubk->pkey.dsa->g);
58 dh->p = BN_dup(pubk->pkey.dsa->p);
59 dh->priv_key = BN_dup(priv_key);
60 ret=compute_pair_key_le(dh_key,((DSA *)(EVP_PKEY_get0(pubk)))->pub_key,dh) ;
63 init_gost_hash_ctx(&hash_ctx,&GostR3411_94_CryptoProParamSet);
64 start_hash(&hash_ctx);
65 hash_block(&hash_ctx,dh_key,128);
66 finish_hash(&hash_ctx,shared_key);
67 done_gost_hash_ctx(&hash_ctx);
71 /* EVP_PKEY_METHOD callback derive. Implements VKO R 34.10-94 */
73 int pkey_gost94_derive(EVP_PKEY_CTX *ctx,unsigned char *key,size_t *keylen)
75 EVP_PKEY *pubk = EVP_PKEY_CTX_get0_peerkey(ctx);
76 EVP_PKEY *mykey = EVP_PKEY_CTX_get0_pkey(ctx);
78 if (key == NULL) return 1;
80 return make_cp_exchange_key(gost_get0_priv_key(mykey), pubk, key);
83 /* EVP_PKEY_METHOD callback encrypt for
84 * GOST R 34.10-94 cryptopro modification
88 int pkey_GOST94cp_encrypt(EVP_PKEY_CTX *ctx, unsigned char *out, size_t *outlen, const unsigned char* key, size_t key_len )
90 GOST_KEY_TRANSPORT *gkt=NULL;
91 unsigned char shared_key[32], ukm[8],crypted_key[44];
92 const struct gost_cipher_info *param=get_encryption_params(NULL);
93 EVP_PKEY *pubk = EVP_PKEY_CTX_get0_pkey(ctx);
94 struct gost_pmeth_data *data = EVP_PKEY_CTX_get_data(ctx);
96 int key_is_ephemeral=1;
97 EVP_PKEY *mykey = EVP_PKEY_CTX_get0_peerkey(ctx);
99 /* Do not use vizir cipher parameters with cryptopro */
100 if (!get_gost_engine_param(GOST_PARAM_CRYPT_PARAMS) && param == gost_cipher_list)
102 param= gost_cipher_list+1;
107 /* If key already set, it is not ephemeral */
109 if (!gost_get0_priv_key(mykey))
111 GOSTerr(GOST_F_PKEY_GOST94CP_ENCRYPT,
112 GOST_R_NO_PRIVATE_PART_OF_NON_EPHEMERAL_KEYPAIR);
118 /* Otherwise generate ephemeral key */
119 key_is_ephemeral = 1;
122 mykey = EVP_PKEY_new();
123 EVP_PKEY_assign(mykey, EVP_PKEY_base_id(pubk),DSA_new());
124 EVP_PKEY_copy_parameters(mykey,pubk);
125 if (!gost_sign_keygen(EVP_PKEY_get0(mykey)))
132 make_cp_exchange_key(gost_get0_priv_key(mykey),pubk,shared_key);
133 if (data->shared_ukm)
135 memcpy(ukm,data->shared_ukm,8);
139 if (RAND_bytes(ukm,8)<=0)
141 GOSTerr(GOST_F_PKEY_GOST94CP_ENCRYPT,
142 GOST_R_RANDOM_GENERATOR_FAILURE);
148 gost_init(&cctx,param->sblock);
149 keyWrapCryptoPro(&cctx,shared_key,ukm,key,crypted_key);
151 gkt = GOST_KEY_TRANSPORT_new();
156 if(!ASN1_OCTET_STRING_set(gkt->key_agreement_info->eph_iv,
161 if (!ASN1_OCTET_STRING_set(gkt->key_info->imit,crypted_key+40,4))
165 if (!ASN1_OCTET_STRING_set(gkt->key_info->encrypted_key,crypted_key+8,32))
169 if (key_is_ephemeral) {
170 if (!X509_PUBKEY_set(&gkt->key_agreement_info->ephem_key,out?mykey:pubk))
172 GOSTerr(GOST_F_PKEY_GOST94CP_ENCRYPT,GOST_R_CANNOT_PACK_EPHEMERAL_KEY);
175 if (out) EVP_PKEY_free(mykey);
177 ASN1_OBJECT_free(gkt->key_agreement_info->cipher);
178 gkt->key_agreement_info->cipher = OBJ_nid2obj(param->nid);
179 *outlen = i2d_GOST_KEY_TRANSPORT(gkt,out?&out:NULL);
182 GOSTerr(GOST_F_PKEY_GOST94CP_ENCRYPT,GOST_R_ERROR_PACKING_KEY_TRANSPORT_INFO);
185 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) <= 0)
190 GOSTerr(GOST_F_PKEY_GOST94CP_ENCRYPT,
191 GOST_R_CTRL_CALL_FAILED);
195 GOST_KEY_TRANSPORT_free(gkt);
198 if (key_is_ephemeral) {
199 EVP_PKEY_free(mykey);
201 GOSTerr(GOST_F_PKEY_GOST94CP_ENCRYPT,
202 GOST_R_MALLOC_FAILURE);
204 GOST_KEY_TRANSPORT_free(gkt);
209 /* EVP_PLEY_METHOD callback decrypt for
210 * GOST R 34.10-94 cryptopro modification
212 int pkey_GOST94cp_decrypt(EVP_PKEY_CTX *ctx, unsigned char *key, size_t *key_len,const unsigned char *in, size_t in_len) {
213 const unsigned char *p = in;
214 GOST_KEY_TRANSPORT *gkt = NULL;
215 unsigned char wrappedKey[44];
216 unsigned char sharedKey[32];
218 const struct gost_cipher_info *param=NULL;
219 EVP_PKEY *eph_key=NULL, *peerkey=NULL;
220 EVP_PKEY *priv= EVP_PKEY_CTX_get0_pkey(ctx);
228 gkt = d2i_GOST_KEY_TRANSPORT(NULL,(const unsigned char **)&p,
232 GOSTerr(GOST_F_PKEY_GOST94CP_DECRYPT,GOST_R_ERROR_PARSING_KEY_TRANSPORT_INFO);
235 eph_key = X509_PUBKEY_get(gkt->key_agreement_info->ephem_key);
238 if (EVP_PKEY_derive_set_peer(ctx, eph_key) <= 0)
240 GOSTerr(GOST_F_PKEY_GOST94CP_DECRYPT,
241 GOST_R_INCOMPATIBLE_PEER_KEY);
247 /* Set control "public key from client certificate used" */
248 if (EVP_PKEY_CTX_ctrl(ctx, -1, -1, EVP_PKEY_CTRL_PEER_KEY, 3, NULL) <= 0)
250 GOSTerr(GOST_F_PKEY_GOST94CP_DECRYPT,
251 GOST_R_CTRL_CALL_FAILED);
255 peerkey = EVP_PKEY_CTX_get0_peerkey(ctx);
258 GOSTerr(GOST_F_PKEY_GOST94CP_DECRYPT,
263 param = get_encryption_params(gkt->key_agreement_info->cipher);
268 gost_init(&cctx,param->sblock);
269 OPENSSL_assert(gkt->key_agreement_info->eph_iv->length==8);
270 memcpy(wrappedKey,gkt->key_agreement_info->eph_iv->data,8);
271 OPENSSL_assert(gkt->key_info->encrypted_key->length==32);
272 memcpy(wrappedKey+8,gkt->key_info->encrypted_key->data,32);
273 OPENSSL_assert(gkt->key_info->imit->length==4);
274 memcpy(wrappedKey+40,gkt->key_info->imit->data,4);
275 make_cp_exchange_key(gost_get0_priv_key(priv),peerkey,sharedKey);
276 if (!keyUnwrapCryptoPro(&cctx,sharedKey,wrappedKey,key))
278 GOSTerr(GOST_F_PKEY_GOST94CP_DECRYPT,
279 GOST_R_ERROR_COMPUTING_SHARED_KEY);
283 EVP_PKEY_free(eph_key);
284 GOST_KEY_TRANSPORT_free(gkt);
287 EVP_PKEY_free(eph_key);
288 GOST_KEY_TRANSPORT_free(gkt);