279 lines
8.9 KiB
C
279 lines
8.9 KiB
C
/**********************************************************************
|
|
* gost94_keyx.c *
|
|
* Copyright (c) 2005-2006 Cryptocom LTD *
|
|
* This file is distributed under the same license as OpenSSL *
|
|
* *
|
|
* Implements generation and parsing of GOST_KEY_TRANSPORT for *
|
|
* GOST R 34.10-94 algorithms *
|
|
* *
|
|
* Requires OpenSSL 0.9.9 for compilation *
|
|
**********************************************************************/
|
|
#include <string.h>
|
|
#include <openssl/dh.h>
|
|
#include <openssl/rand.h>
|
|
#include <openssl/err.h>
|
|
#include <openssl/evp.h>
|
|
#include <openssl/objects.h>
|
|
|
|
#include "gost89.h"
|
|
#include "gosthash.h"
|
|
#include "e_gost_err.h"
|
|
#include "gost_keywrap.h"
|
|
#include "gost_lcl.h"
|
|
/* Common functions for both 94 and 2001 key exchange schemes */
|
|
/*
|
|
* Implementation of the Diffi-Hellman key agreement scheme based on GOST-94
|
|
* keys
|
|
*/
|
|
|
|
/*
|
|
* Computes Diffie-Hellman key and stores it into buffer in little-endian
|
|
* byte order as expected by both versions of GOST 94 algorithm
|
|
*/
|
|
static int compute_pair_key_le(unsigned char *pair_key, BIGNUM *pub_key,
|
|
DH *dh)
|
|
{
|
|
unsigned char be_key[128];
|
|
int i, key_size;
|
|
key_size = DH_compute_key(be_key, pub_key, dh);
|
|
if (!key_size)
|
|
return 0;
|
|
memset(pair_key, 0, 128);
|
|
for (i = 0; i < key_size; i++) {
|
|
pair_key[i] = be_key[key_size - 1 - i];
|
|
}
|
|
return key_size;
|
|
}
|
|
|
|
/*
|
|
* Computes 256 bit Key exchange key as specified in RFC 4357
|
|
*/
|
|
static int make_cp_exchange_key(BIGNUM *priv_key, EVP_PKEY *pubk,
|
|
unsigned char *shared_key)
|
|
{
|
|
unsigned char dh_key[128];
|
|
int ret;
|
|
gost_hash_ctx hash_ctx;
|
|
DH *dh = DH_new();
|
|
|
|
if (!dh)
|
|
return 0;
|
|
memset(dh_key, 0, 128);
|
|
dh->g = BN_dup(pubk->pkey.dsa->g);
|
|
dh->p = BN_dup(pubk->pkey.dsa->p);
|
|
dh->priv_key = BN_dup(priv_key);
|
|
ret =
|
|
compute_pair_key_le(dh_key, ((DSA *)(EVP_PKEY_get0(pubk)))->pub_key,
|
|
dh);
|
|
DH_free(dh);
|
|
if (!ret)
|
|
return 0;
|
|
init_gost_hash_ctx(&hash_ctx, &GostR3411_94_CryptoProParamSet);
|
|
start_hash(&hash_ctx);
|
|
hash_block(&hash_ctx, dh_key, 128);
|
|
finish_hash(&hash_ctx, shared_key);
|
|
done_gost_hash_ctx(&hash_ctx);
|
|
return 1;
|
|
}
|
|
|
|
/* EVP_PKEY_METHOD callback derive. Implements VKO R 34.10-94 */
|
|
|
|
int pkey_gost94_derive(EVP_PKEY_CTX *ctx, unsigned char *key, size_t *keylen)
|
|
{
|
|
EVP_PKEY *pubk = EVP_PKEY_CTX_get0_peerkey(ctx);
|
|
EVP_PKEY *mykey = EVP_PKEY_CTX_get0_pkey(ctx);
|
|
*keylen = 32;
|
|
if (key == NULL)
|
|
return 1;
|
|
|
|
return make_cp_exchange_key(gost_get0_priv_key(mykey), pubk, key);
|
|
}
|
|
|
|
/*
|
|
* EVP_PKEY_METHOD callback encrypt for GOST R 34.10-94 cryptopro
|
|
* modification
|
|
*/
|
|
|
|
int pkey_GOST94cp_encrypt(EVP_PKEY_CTX *ctx, unsigned char *out,
|
|
size_t *outlen, const unsigned char *key,
|
|
size_t key_len)
|
|
{
|
|
GOST_KEY_TRANSPORT *gkt = NULL;
|
|
unsigned char shared_key[32], ukm[8], crypted_key[44];
|
|
const struct gost_cipher_info *param = get_encryption_params(NULL);
|
|
EVP_PKEY *pubk = EVP_PKEY_CTX_get0_pkey(ctx);
|
|
struct gost_pmeth_data *data = EVP_PKEY_CTX_get_data(ctx);
|
|
gost_ctx cctx;
|
|
int key_is_ephemeral = 1;
|
|
EVP_PKEY *mykey = EVP_PKEY_CTX_get0_peerkey(ctx);
|
|
|
|
/* Do not use vizir cipher parameters with cryptopro */
|
|
if (!get_gost_engine_param(GOST_PARAM_CRYPT_PARAMS)
|
|
&& param == gost_cipher_list) {
|
|
param = gost_cipher_list + 1;
|
|
}
|
|
|
|
if (mykey) {
|
|
/* If key already set, it is not ephemeral */
|
|
key_is_ephemeral = 0;
|
|
if (!gost_get0_priv_key(mykey)) {
|
|
GOSTerr(GOST_F_PKEY_GOST94CP_ENCRYPT,
|
|
GOST_R_NO_PRIVATE_PART_OF_NON_EPHEMERAL_KEYPAIR);
|
|
goto err;
|
|
}
|
|
} else {
|
|
/* Otherwise generate ephemeral key */
|
|
key_is_ephemeral = 1;
|
|
if (out) {
|
|
mykey = EVP_PKEY_new();
|
|
EVP_PKEY_assign(mykey, EVP_PKEY_base_id(pubk), DSA_new());
|
|
EVP_PKEY_copy_parameters(mykey, pubk);
|
|
if (!gost_sign_keygen(EVP_PKEY_get0(mykey))) {
|
|
goto err;
|
|
}
|
|
}
|
|
}
|
|
if (out)
|
|
make_cp_exchange_key(gost_get0_priv_key(mykey), pubk, shared_key);
|
|
if (data->shared_ukm) {
|
|
memcpy(ukm, data->shared_ukm, 8);
|
|
} else if (out) {
|
|
if (RAND_bytes(ukm, 8) <= 0) {
|
|
GOSTerr(GOST_F_PKEY_GOST94CP_ENCRYPT,
|
|
GOST_R_RANDOM_GENERATOR_FAILURE);
|
|
goto err;
|
|
}
|
|
}
|
|
|
|
if (out) {
|
|
gost_init(&cctx, param->sblock);
|
|
keyWrapCryptoPro(&cctx, shared_key, ukm, key, crypted_key);
|
|
}
|
|
gkt = GOST_KEY_TRANSPORT_new();
|
|
if (!gkt) {
|
|
goto memerr;
|
|
}
|
|
if (!ASN1_OCTET_STRING_set(gkt->key_agreement_info->eph_iv, ukm, 8)) {
|
|
goto memerr;
|
|
}
|
|
if (!ASN1_OCTET_STRING_set(gkt->key_info->imit, crypted_key + 40, 4)) {
|
|
goto memerr;
|
|
}
|
|
if (!ASN1_OCTET_STRING_set
|
|
(gkt->key_info->encrypted_key, crypted_key + 8, 32)) {
|
|
goto memerr;
|
|
}
|
|
if (key_is_ephemeral) {
|
|
if (!X509_PUBKEY_set
|
|
(&gkt->key_agreement_info->ephem_key, out ? mykey : pubk)) {
|
|
GOSTerr(GOST_F_PKEY_GOST94CP_ENCRYPT,
|
|
GOST_R_CANNOT_PACK_EPHEMERAL_KEY);
|
|
goto err;
|
|
}
|
|
if (out)
|
|
EVP_PKEY_free(mykey);
|
|
}
|
|
ASN1_OBJECT_free(gkt->key_agreement_info->cipher);
|
|
gkt->key_agreement_info->cipher = OBJ_nid2obj(param->nid);
|
|
*outlen = i2d_GOST_KEY_TRANSPORT(gkt, out ? &out : NULL);
|
|
if (*outlen <= 0) {
|
|
GOSTerr(GOST_F_PKEY_GOST94CP_ENCRYPT,
|
|
GOST_R_ERROR_PACKING_KEY_TRANSPORT_INFO);
|
|
goto err;
|
|
}
|
|
if (!key_is_ephemeral) {
|
|
/* Set control "public key from client certificate used" */
|
|
if (EVP_PKEY_CTX_ctrl(ctx, -1, -1, EVP_PKEY_CTRL_PEER_KEY, 3, NULL) <=
|
|
0) {
|
|
GOSTerr(GOST_F_PKEY_GOST94CP_ENCRYPT, GOST_R_CTRL_CALL_FAILED);
|
|
goto err;
|
|
}
|
|
}
|
|
GOST_KEY_TRANSPORT_free(gkt);
|
|
return 1;
|
|
memerr:
|
|
if (key_is_ephemeral) {
|
|
EVP_PKEY_free(mykey);
|
|
}
|
|
GOSTerr(GOST_F_PKEY_GOST94CP_ENCRYPT, ERR_R_MALLOC_FAILURE);
|
|
err:
|
|
GOST_KEY_TRANSPORT_free(gkt);
|
|
return -1;
|
|
}
|
|
|
|
/*
|
|
* EVP_PLEY_METHOD callback decrypt for GOST R 34.10-94 cryptopro
|
|
* modification
|
|
*/
|
|
int pkey_GOST94cp_decrypt(EVP_PKEY_CTX *ctx, unsigned char *key,
|
|
size_t *key_len, const unsigned char *in,
|
|
size_t in_len)
|
|
{
|
|
const unsigned char *p = in;
|
|
GOST_KEY_TRANSPORT *gkt = NULL;
|
|
unsigned char wrappedKey[44];
|
|
unsigned char sharedKey[32];
|
|
gost_ctx cctx;
|
|
const struct gost_cipher_info *param = NULL;
|
|
EVP_PKEY *eph_key = NULL, *peerkey = NULL;
|
|
EVP_PKEY *priv = EVP_PKEY_CTX_get0_pkey(ctx);
|
|
|
|
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_GOST94CP_DECRYPT,
|
|
GOST_R_ERROR_PARSING_KEY_TRANSPORT_INFO);
|
|
return 0;
|
|
}
|
|
eph_key = X509_PUBKEY_get(gkt->key_agreement_info->ephem_key);
|
|
if (eph_key) {
|
|
if (EVP_PKEY_derive_set_peer(ctx, eph_key) <= 0) {
|
|
GOSTerr(GOST_F_PKEY_GOST94CP_DECRYPT,
|
|
GOST_R_INCOMPATIBLE_PEER_KEY);
|
|
goto err;
|
|
}
|
|
} else {
|
|
/* Set control "public key from client certificate used" */
|
|
if (EVP_PKEY_CTX_ctrl(ctx, -1, -1, EVP_PKEY_CTRL_PEER_KEY, 3, NULL) <=
|
|
0) {
|
|
GOSTerr(GOST_F_PKEY_GOST94CP_DECRYPT, GOST_R_CTRL_CALL_FAILED);
|
|
goto err;
|
|
}
|
|
}
|
|
peerkey = EVP_PKEY_CTX_get0_peerkey(ctx);
|
|
if (!peerkey) {
|
|
GOSTerr(GOST_F_PKEY_GOST94CP_DECRYPT, GOST_R_NO_PEER_KEY);
|
|
goto err;
|
|
}
|
|
|
|
param = get_encryption_params(gkt->key_agreement_info->cipher);
|
|
if (!param) {
|
|
goto err;
|
|
}
|
|
|
|
gost_init(&cctx, 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);
|
|
make_cp_exchange_key(gost_get0_priv_key(priv), peerkey, sharedKey);
|
|
if (!keyUnwrapCryptoPro(&cctx, sharedKey, wrappedKey, key)) {
|
|
GOSTerr(GOST_F_PKEY_GOST94CP_DECRYPT,
|
|
GOST_R_ERROR_COMPUTING_SHARED_KEY);
|
|
goto err;
|
|
}
|
|
|
|
EVP_PKEY_free(eph_key);
|
|
GOST_KEY_TRANSPORT_free(gkt);
|
|
return 1;
|
|
err:
|
|
EVP_PKEY_free(eph_key);
|
|
GOST_KEY_TRANSPORT_free(gkt);
|
|
return -1;
|
|
}
|