engines/ccgost/gost2001_keyx.c - third_party/openssl - Git at Google

 /**********************************************************************
  *                          gost_keyx.c                               *
  *             Copyright (c) 2005-2006 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/rand.h>
 #include <string.h>
 #include <openssl/objects.h>
 #include "gost89.h"
 #include "gosthash.h"
 #include "e_gost_err.h"
 #include "gost_keywrap.h"
 #include "gost_lcl.h"
 #include "gost2001_keyx.h"

 /* Transform ECDH shared key into little endian as required by Cryptocom
  * key exchange */
 static void *make_key_le(const void *in, size_t inlen, void *out, size_t *outlen)
 	{
 	const char* inbuf= in;
 	char* outbuf= out;
 	int i;
 	if (*outlen < inlen)
 		{
 		return NULL;
 		}
 	for (i=0;i<inlen;i++)
 		{
 		outbuf[inlen-1-i]=inbuf[i];
 		}
 	*outlen = inlen;
 	return out;
 	}

 /* Create gost 2001 ephemeral key with same parameters as peer key */
 static EC_KEY *make_ec_ephemeral_key(EC_KEY *peer_key,BIGNUM *seckey)
 	{
 	EC_KEY *out = EC_KEY_new();
 	EC_KEY_copy(out,peer_key);
 	EC_KEY_set_private_key(out,seckey);
 	gost2001_compute_public(out);
 	return out;
 	}
 /* Packs GOST elliptic curve key into EVP_PKEY setting same parameters
  * as in passed pubkey
  */
 static EVP_PKEY *ec_ephemeral_key_to_EVP(EVP_PKEY *pubk,int type,EC_KEY *ephemeral)
 	{
 	EVP_PKEY *newkey;
 	newkey = EVP_PKEY_new();
 	EVP_PKEY_assign(newkey,type,ephemeral);
 	return newkey;
 	}

 /*
  * EVP_PKEY_METHOD callback encrypt
  * Implementation of GOST2001 key transport, cryptocom variation
  */

 int pkey_GOST01cc_encrypt (EVP_PKEY_CTX *pctx,unsigned char *out,
 	size_t *out_len, const unsigned char *key,size_t key_len)
 	{
 	EVP_PKEY *pubk = EVP_PKEY_CTX_get0_pkey(pctx);
 	struct gost_pmeth_data *data = EVP_PKEY_CTX_get_data(pctx);
 	GOST_KEY_TRANSPORT *gkt = NULL;
 	int ret=0;
 	gost_ctx ctx;
 	EC_KEY *ephemeral=NULL;
 	const EC_POINT *pub_key_point=NULL;
 	unsigned char shared_key[32],encrypted_key[32],hmac[4],
 		iv[8]={0,0,0,0,0,0,0,0};
 	ephemeral = make_ec_ephemeral_key(EVP_PKEY_get0(pubk), gost_get_priv_key(data->eph_seckey));
 	if (!ephemeral) goto err;
 	/* compute shared key */
 	pub_key_point=EC_KEY_get0_public_key(EVP_PKEY_get0(pubk));
 	if (!ECDH_compute_key(shared_key,32,pub_key_point,ephemeral,make_key_le))
 		{
 		GOSTerr(GOST_F_PKEY_GOST01CC_ENCRYPT,GOST_R_ERROR_COMPUTING_SHARED_KEY);
 		goto err;
 		}
 	/* encrypt session key */
 	gost_init(&ctx, &GostR3411_94_CryptoProParamSet);
 	gost_key(&ctx,shared_key);
 	encrypt_cryptocom_key(key,key_len,encrypted_key,&ctx);
 	/* compute hmac of session key */
 	if (!gost_mac(&ctx,32,key,32,hmac))
 		{
 		GOSTerr(GOST_F_PKEY_GOST01CC_ENCRYPT,GOST_R_ERROR_COMPUTING_MAC);
 		return -1;
 		}
 	gkt = GOST_KEY_TRANSPORT_new();
 	if (!gkt)
 		{
 		GOSTerr(GOST_F_PKEY_GOST01CC_ENCRYPT,GOST_R_NO_MEMORY);
 		return -1;
 		}
 	/* Store IV which is always zero in our case */
 	if (!ASN1_OCTET_STRING_set(gkt->key_agreement_info->eph_iv,iv,8))
 		{
 		GOSTerr(GOST_F_PKEY_GOST01CC_ENCRYPT,GOST_R_ERROR_STORING_IV);
 		goto err;
 		}
 	if (!ASN1_OCTET_STRING_set(gkt->key_info->imit,hmac,4))
 		{
 		GOSTerr(GOST_F_PKEY_GOST01CC_ENCRYPT,GOST_R_ERROR_STORING_MAC);
 		goto err;
 		}
 	if (!ASN1_OCTET_STRING_set(gkt->key_info->encrypted_key,encrypted_key,32))
 		{
 		GOSTerr(GOST_F_PKEY_GOST01CC_ENCRYPT,GOST_R_ERROR_STORING_ENCRYPTED_KEY);
 		goto err;
 		}

 	if (!X509_PUBKEY_set(&gkt->key_agreement_info->ephem_key,data->eph_seckey))
 		{
 		GOSTerr(GOST_F_PKEY_GOST01CC_ENCRYPT,GOST_R_CANNOT_PACK_EPHEMERAL_KEY);
 		goto err;
 		}
 	ASN1_OBJECT_free(gkt->key_agreement_info->cipher);
 	gkt->key_agreement_info->cipher = OBJ_nid2obj(NID_id_Gost28147_89_cc);
 	if ((*out_len = i2d_GOST_KEY_TRANSPORT(gkt,&out))>0) ret = 1;
 	;
 	err:
 	if (gkt) GOST_KEY_TRANSPORT_free(gkt);
 	return ret;
 	}
 /*
  * EVP_PKEY_METHOD callback decrypt
  * Implementation of GOST2001 key transport, cryptocom variation
  */
 int pkey_GOST01cc_decrypt (EVP_PKEY_CTX *pctx, unsigned char *key, size_t *key_len, const unsigned char *in, size_t in_len)
 	{
 	/* Form DH params from compute shared key */
 	EVP_PKEY *priv=EVP_PKEY_CTX_get0_pkey(pctx);
 	GOST_KEY_TRANSPORT *gkt = NULL;
 	const unsigned char *p=in;
 	unsigned char shared_key[32];
 	unsigned char hmac[4],hmac_comp[4];
 	unsigned char iv[8];
 	int i;
 	gost_ctx ctx;
 	const EC_POINT *pub_key_point;
 	EVP_PKEY *eph_key;

 	if (!key)
 		{
 		*key_len = 32;
 		return 1;
 		}
 	/* Parse passed octet string and find out public key, iv and HMAC*/
 	gkt = d2i_GOST_KEY_TRANSPORT(NULL,(const unsigned char **)&p,
 		in_len);
 	if (!gkt)
 		{
 		GOSTerr(GOST_F_PKEY_GOST01CC_DECRYPT,GOST_R_ERROR_PARSING_KEY_TRANSPORT_INFO);
 		return 0;
 		}
 	eph_key = X509_PUBKEY_get(gkt->key_agreement_info->ephem_key);
 	/* Initialization vector is really ignored here */
 	OPENSSL_assert(gkt->key_agreement_info->eph_iv->length==8);
 	memcpy(iv,gkt->key_agreement_info->eph_iv->data,8);
 	/* HMAC should be computed and checked */
 	OPENSSL_assert(gkt->key_info->imit->length==4);
 	memcpy(hmac,gkt->key_info->imit->data,4);
 	/* Compute shared key */
 	pub_key_point=EC_KEY_get0_public_key(EVP_PKEY_get0(eph_key));
 	i=ECDH_compute_key(shared_key,32,pub_key_point,EVP_PKEY_get0(priv),make_key_le);
 	EVP_PKEY_free(eph_key);
 	if (!i)
 		{
 		GOSTerr(GOST_F_PKEY_GOST01CC_DECRYPT,GOST_R_ERROR_COMPUTING_SHARED_KEY);
 		GOST_KEY_TRANSPORT_free(gkt);
 		return 0;
 		}
 	/* Decrypt session key */
 	gost_init(&ctx, &GostR3411_94_CryptoProParamSet);
 	gost_key(&ctx,shared_key);

 	if (!decrypt_cryptocom_key(key,*key_len,gkt->key_info->encrypted_key->data,
 			gkt->key_info->encrypted_key->length, &ctx))
 		{
 		GOST_KEY_TRANSPORT_free(gkt);
 		return 0;
 		}
 	GOST_KEY_TRANSPORT_free(gkt);
 	/* check HMAC of session key*/
 	if (!gost_mac(&ctx,32,key,32,hmac_comp))
 		{
 		GOSTerr(GOST_F_PKEY_GOST01CC_DECRYPT,GOST_R_ERROR_COMPUTING_MAC);
 		return 0;
 		}
 	/* HMAC of session key is not correct */
     if (memcmp(hmac,hmac_comp,4)!=0)
 		{
 		GOSTerr(GOST_F_PKEY_GOST01CC_DECRYPT,GOST_R_SESSION_KEY_MAC_DOES_NOT_MATCH);
 		return 0;
 		}
 	return 1;
 	}

 /* Implementation of CryptoPro VKO 34.10-2001 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)
 	{
 	unsigned char ukm_be[8],databuf[64],hashbuf[64];
 	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;
 	gost_hash_ctx hash_ctx;
 	BN_CTX *ctx = BN_CTX_new();

 	for (i=0;i<8;i++)
 		{
 		ukm_be[7-i]=ukm[i];
 		}
 	BN_CTX_start(ctx);
 	UKM=getbnfrombuf(ukm_be,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);
 	EC_POINT_mul(EC_KEY_get0_group(priv_key),pnt,NULL,pub_key,p,ctx);
 	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,32);
 	store_bignum(X,databuf+32,32);
  	/* And reverse byte order of whole buffer */
 	for (i=0;i<64;i++)
 		{
 		hashbuf[63-i]=databuf[i];
 		}
 	init_gost_hash_ctx(&hash_ctx,&GostR3411_94_CryptoProParamSet);
 	start_hash(&hash_ctx);
 	hash_block(&hash_ctx,hashbuf,64);
 	finish_hash(&hash_ctx,shared_key);
 	done_gost_hash_ctx(&hash_ctx);
 	BN_free(UKM);
 	BN_CTX_end(ctx);
 	BN_CTX_free(ctx);
 	EC_POINT_free(pnt);
 	return 32;
 	}

 /* Generates ephemeral key based on pubk algorithm
  * computes shared key using VKO and returns filled up
  * GOST_KEY_TRANSPORT structure
  */
 /* Public, because it would be needed in SSL implementation */
 GOST_KEY_TRANSPORT *make_rfc4490_keytransport_2001(EVP_PKEY *pubk,BIGNUM *eph_key,
 	const unsigned char *key,size_t keylen, unsigned char *ukm,
 	size_t ukm_len)
 	{

 	const struct gost_cipher_info *param=get_encryption_params(NULL);
 	EC_KEY *ephemeral = NULL;
 	GOST_KEY_TRANSPORT *gkt=NULL;
 	const EC_POINT *pub_key_point = EC_KEY_get0_public_key(EVP_PKEY_get0(pubk));
 	unsigned char shared_key[32],crypted_key[44];
 	gost_ctx ctx;
 	EVP_PKEY *newkey=NULL;

 	/* 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;
 		}
 	ephemeral = make_ec_ephemeral_key(EVP_PKEY_get0(pubk),eph_key);
     VKO_compute_key(shared_key,32,pub_key_point,ephemeral,ukm);
 	gost_init(&ctx,param->sblock);
 	keyWrapCryptoPro(&ctx,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;
 		}
 	newkey = ec_ephemeral_key_to_EVP(pubk,NID_id_GostR3410_2001,ephemeral);
 	if (!X509_PUBKEY_set(&gkt->key_agreement_info->ephem_key,newkey))
 		{
 		GOSTerr(GOST_F_MAKE_RFC4490_KEYTRANSPORT_2001,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);
 	EVP_PKEY_free(newkey);
 	return gkt;
 	memerr:
 	GOSTerr(GOST_F_MAKE_RFC4490_KEYTRANSPORT_2001,
 		GOST_R_MALLOC_FAILURE);
 	err:
 	GOST_KEY_TRANSPORT_free(gkt);
 	return NULL;
 	}

 /*
  * EVP_PKEY_METHOD callback encrypt
  * Implementation of GOST2001 key transport, cryptopo variation
  */

 int pkey_GOST01cp_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);
 	unsigned char ukm[8];
 	int ret=0;
 	if (RAND_bytes(ukm,8)<=0)
 		{
 		GOSTerr(GOST_F_PKEY_GOST01CP_ENCRYPT,
 			GOST_R_RANDOM_GENERATOR_FAILURE);
 		return 0;
 		}

 	if (!(gkt=make_rfc4490_keytransport_2001(pubk,gost_get_priv_key(data->eph_seckey),key, key_len,ukm,8)))
 		{
 		goto err;
 		}
 	if ((*out_len = i2d_GOST_KEY_TRANSPORT(gkt,&out))>0) ret =1;
 	GOST_KEY_TRANSPORT_free(gkt);
 	return ret;
 	err:
 	GOST_KEY_TRANSPORT_free(gkt);
 	return -1;
 	}
 /* Public, because it would be needed in SSL implementation */
 int decrypt_rfc4490_shared_key_2001(EVP_PKEY *priv,GOST_KEY_TRANSPORT *gkt,
 	unsigned char *key_buf,int key_buf_len)
 	{
 	unsigned char wrappedKey[44];
 	unsigned char sharedKey[32];
 	gost_ctx ctx;
 	const struct gost_cipher_info *param=NULL;
 	EVP_PKEY *eph_key=NULL;

 	eph_key = X509_PUBKEY_get(gkt->key_agreement_info->ephem_key);
 	param = get_encryption_params(gkt->key_agreement_info->cipher);
 	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);
 	VKO_compute_key(sharedKey,32,EC_KEY_get0_public_key(EVP_PKEY_get0(eph_key)),
 		EVP_PKEY_get0(priv),wrappedKey);
 	if (!keyUnwrapCryptoPro(&ctx,sharedKey,wrappedKey,key_buf))
 		{
 		GOSTerr(GOST_F_PKCS7_GOST94CP_KEY_TRANSPORT_DECRYPT,
 			GOST_R_ERROR_COMPUTING_SHARED_KEY);
 		goto err;
 		}

 	EVP_PKEY_free(eph_key);
 	return 32;
 	err:
 	EVP_PKEY_free(eph_key);
 	return -1;
 	}
 /*
  * EVP_PKEY_METHOD callback decrypt
  * Implementation of GOST2001 key transport, cryptopo variation
  */
 int pkey_GOST01cp_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;

 	if (!key)
 		{
 		*key_len = 32;
 		return 1;
 		}
 	gkt = d2i_GOST_KEY_TRANSPORT(NULL,(const unsigned char **)&p,
 		in_len);
 	if (!gkt)
 		{
 		GOSTerr(GOST_F_PKCS7_GOST94CP_KEY_TRANSPORT_DECRYPT,GOST_R_ERROR_PARSING_KEY_TRANSPORT_INFO);
 		return -1;
 		}
 	ret = 	decrypt_rfc4490_shared_key_2001(priv,gkt,key,*key_len);
 	GOST_KEY_TRANSPORT_free(gkt);
 	return ret;
 	}
	/**********************************************************************
	* gost_keyx.c *
	* Copyright (c) 2005-2006 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/rand.h>
	#include <string.h>
	#include <openssl/objects.h>
	#include "gost89.h"
	#include "gosthash.h"
	#include "e_gost_err.h"
	#include "gost_keywrap.h"
	#include "gost_lcl.h"
	#include "gost2001_keyx.h"

	/* Transform ECDH shared key into little endian as required by Cryptocom
	* key exchange */
	static void make_key_le(const void in, size_t inlen, void out, size_t outlen)
	{
	const char* inbuf= in;
	char* outbuf= out;
	int i;
	if (*outlen < inlen)
	{
	return NULL;
	}
	for (i=0;i<inlen;i++)
	{
	outbuf[inlen-1-i]=inbuf[i];
	}
	*outlen = inlen;
	return out;
	}

	/* Create gost 2001 ephemeral key with same parameters as peer key */
	static EC_KEY make_ec_ephemeral_key(EC_KEY peer_key,BIGNUM *seckey)
	{
	EC_KEY *out = EC_KEY_new();
	EC_KEY_copy(out,peer_key);
	EC_KEY_set_private_key(out,seckey);
	gost2001_compute_public(out);
	return out;
	}
	/* Packs GOST elliptic curve key into EVP_PKEY setting same parameters
	* as in passed pubkey
	*/
	static EVP_PKEY ec_ephemeral_key_to_EVP(EVP_PKEY pubk,int type,EC_KEY *ephemeral)
	{
	EVP_PKEY *newkey;
	newkey = EVP_PKEY_new();
	EVP_PKEY_assign(newkey,type,ephemeral);
	return newkey;
	}

	/*
	* EVP_PKEY_METHOD callback encrypt
	* Implementation of GOST2001 key transport, cryptocom variation
	*/

	int pkey_GOST01cc_encrypt (EVP_PKEY_CTX pctx,unsigned char out,
	size_t out_len, const unsigned char key,size_t key_len)
	{
	EVP_PKEY *pubk = EVP_PKEY_CTX_get0_pkey(pctx);
	struct gost_pmeth_data *data = EVP_PKEY_CTX_get_data(pctx);
	GOST_KEY_TRANSPORT *gkt = NULL;
	int ret=0;
	gost_ctx ctx;
	EC_KEY *ephemeral=NULL;
	const EC_POINT *pub_key_point=NULL;
	unsigned char shared_key[32],encrypted_key[32],hmac[4],
	iv[8]={0,0,0,0,0,0,0,0};
	ephemeral = make_ec_ephemeral_key(EVP_PKEY_get0(pubk), gost_get_priv_key(data->eph_seckey));
	if (!ephemeral) goto err;
	/* compute shared key */
	pub_key_point=EC_KEY_get0_public_key(EVP_PKEY_get0(pubk));
	if (!ECDH_compute_key(shared_key,32,pub_key_point,ephemeral,make_key_le))
	{
	GOSTerr(GOST_F_PKEY_GOST01CC_ENCRYPT,GOST_R_ERROR_COMPUTING_SHARED_KEY);
	goto err;
	}
	/* encrypt session key */
	gost_init(&ctx, &GostR3411_94_CryptoProParamSet);
	gost_key(&ctx,shared_key);
	encrypt_cryptocom_key(key,key_len,encrypted_key,&ctx);
	/* compute hmac of session key */
	if (!gost_mac(&ctx,32,key,32,hmac))
	{
	GOSTerr(GOST_F_PKEY_GOST01CC_ENCRYPT,GOST_R_ERROR_COMPUTING_MAC);
	return -1;
	}
	gkt = GOST_KEY_TRANSPORT_new();
	if (!gkt)
	{
	GOSTerr(GOST_F_PKEY_GOST01CC_ENCRYPT,GOST_R_NO_MEMORY);
	return -1;
	}
	/* Store IV which is always zero in our case */
	if (!ASN1_OCTET_STRING_set(gkt->key_agreement_info->eph_iv,iv,8))
	{
	GOSTerr(GOST_F_PKEY_GOST01CC_ENCRYPT,GOST_R_ERROR_STORING_IV);
	goto err;
	}
	if (!ASN1_OCTET_STRING_set(gkt->key_info->imit,hmac,4))
	{
	GOSTerr(GOST_F_PKEY_GOST01CC_ENCRYPT,GOST_R_ERROR_STORING_MAC);
	goto err;
	}
	if (!ASN1_OCTET_STRING_set(gkt->key_info->encrypted_key,encrypted_key,32))
	{
	GOSTerr(GOST_F_PKEY_GOST01CC_ENCRYPT,GOST_R_ERROR_STORING_ENCRYPTED_KEY);
	goto err;
	}

	if (!X509_PUBKEY_set(&gkt->key_agreement_info->ephem_key,data->eph_seckey))
	{
	GOSTerr(GOST_F_PKEY_GOST01CC_ENCRYPT,GOST_R_CANNOT_PACK_EPHEMERAL_KEY);
	goto err;
	}
	ASN1_OBJECT_free(gkt->key_agreement_info->cipher);
	gkt->key_agreement_info->cipher = OBJ_nid2obj(NID_id_Gost28147_89_cc);
	if ((*out_len = i2d_GOST_KEY_TRANSPORT(gkt,&out))>0) ret = 1;
	;
	err:
	if (gkt) GOST_KEY_TRANSPORT_free(gkt);
	return ret;
	}
	/*
	* EVP_PKEY_METHOD callback decrypt
	* Implementation of GOST2001 key transport, cryptocom variation
	*/
	int pkey_GOST01cc_decrypt (EVP_PKEY_CTX pctx, unsigned char key, size_t key_len, const unsigned char in, size_t in_len)
	{
	/* Form DH params from compute shared key */
	EVP_PKEY *priv=EVP_PKEY_CTX_get0_pkey(pctx);
	GOST_KEY_TRANSPORT *gkt = NULL;
	const unsigned char *p=in;
	unsigned char shared_key[32];
	unsigned char hmac[4],hmac_comp[4];
	unsigned char iv[8];
	int i;
	gost_ctx ctx;
	const EC_POINT *pub_key_point;
	EVP_PKEY *eph_key;

	if (!key)
	{
	*key_len = 32;
	return 1;
	}
	/* Parse passed octet string and find out public key, iv and HMAC*/
	gkt = d2i_GOST_KEY_TRANSPORT(NULL,(const unsigned char **)&p,
	in_len);
	if (!gkt)
	{
	GOSTerr(GOST_F_PKEY_GOST01CC_DECRYPT,GOST_R_ERROR_PARSING_KEY_TRANSPORT_INFO);
	return 0;
	}
	eph_key = X509_PUBKEY_get(gkt->key_agreement_info->ephem_key);
	/* Initialization vector is really ignored here */
	OPENSSL_assert(gkt->key_agreement_info->eph_iv->length==8);
	memcpy(iv,gkt->key_agreement_info->eph_iv->data,8);
	/* HMAC should be computed and checked */
	OPENSSL_assert(gkt->key_info->imit->length==4);
	memcpy(hmac,gkt->key_info->imit->data,4);
	/* Compute shared key */
	pub_key_point=EC_KEY_get0_public_key(EVP_PKEY_get0(eph_key));
	i=ECDH_compute_key(shared_key,32,pub_key_point,EVP_PKEY_get0(priv),make_key_le);
	EVP_PKEY_free(eph_key);
	if (!i)
	{
	GOSTerr(GOST_F_PKEY_GOST01CC_DECRYPT,GOST_R_ERROR_COMPUTING_SHARED_KEY);
	GOST_KEY_TRANSPORT_free(gkt);
	return 0;
	}
	/* Decrypt session key */
	gost_init(&ctx, &GostR3411_94_CryptoProParamSet);
	gost_key(&ctx,shared_key);

	if (!decrypt_cryptocom_key(key,*key_len,gkt->key_info->encrypted_key->data,
	gkt->key_info->encrypted_key->length, &ctx))
	{
	GOST_KEY_TRANSPORT_free(gkt);
	return 0;
	}
	GOST_KEY_TRANSPORT_free(gkt);
	/* check HMAC of session key*/
	if (!gost_mac(&ctx,32,key,32,hmac_comp))
	{
	GOSTerr(GOST_F_PKEY_GOST01CC_DECRYPT,GOST_R_ERROR_COMPUTING_MAC);
	return 0;
	}
	/* HMAC of session key is not correct */
	if (memcmp(hmac,hmac_comp,4)!=0)
	{
	GOSTerr(GOST_F_PKEY_GOST01CC_DECRYPT,GOST_R_SESSION_KEY_MAC_DOES_NOT_MATCH);
	return 0;
	}
	return 1;
	}

	/* Implementation of CryptoPro VKO 34.10-2001 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)
	{
	unsigned char ukm_be[8],databuf[64],hashbuf[64];
	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;
	gost_hash_ctx hash_ctx;
	BN_CTX *ctx = BN_CTX_new();

	for (i=0;i<8;i++)
	{
	ukm_be[7-i]=ukm[i];
	}
	BN_CTX_start(ctx);
	UKM=getbnfrombuf(ukm_be,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);
	EC_POINT_mul(EC_KEY_get0_group(priv_key),pnt,NULL,pub_key,p,ctx);
	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,32);
	store_bignum(X,databuf+32,32);
	/* And reverse byte order of whole buffer */
	for (i=0;i<64;i++)
	{
	hashbuf[63-i]=databuf[i];
	}
	init_gost_hash_ctx(&hash_ctx,&GostR3411_94_CryptoProParamSet);
	start_hash(&hash_ctx);
	hash_block(&hash_ctx,hashbuf,64);
	finish_hash(&hash_ctx,shared_key);
	done_gost_hash_ctx(&hash_ctx);
	BN_free(UKM);
	BN_CTX_end(ctx);
	BN_CTX_free(ctx);
	EC_POINT_free(pnt);
	return 32;
	}

	/* Generates ephemeral key based on pubk algorithm
	* computes shared key using VKO and returns filled up
	* GOST_KEY_TRANSPORT structure
	*/
	/* Public, because it would be needed in SSL implementation */
	GOST_KEY_TRANSPORT make_rfc4490_keytransport_2001(EVP_PKEY pubk,BIGNUM *eph_key,
	const unsigned char key,size_t keylen, unsigned char ukm,
	size_t ukm_len)
	{

	const struct gost_cipher_info *param=get_encryption_params(NULL);
	EC_KEY *ephemeral = NULL;
	GOST_KEY_TRANSPORT *gkt=NULL;
	const EC_POINT *pub_key_point = EC_KEY_get0_public_key(EVP_PKEY_get0(pubk));
	unsigned char shared_key[32],crypted_key[44];
	gost_ctx ctx;
	EVP_PKEY *newkey=NULL;

	/* 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;
	}
	ephemeral = make_ec_ephemeral_key(EVP_PKEY_get0(pubk),eph_key);
	VKO_compute_key(shared_key,32,pub_key_point,ephemeral,ukm);
	gost_init(&ctx,param->sblock);
	keyWrapCryptoPro(&ctx,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;
	}
	newkey = ec_ephemeral_key_to_EVP(pubk,NID_id_GostR3410_2001,ephemeral);
	if (!X509_PUBKEY_set(&gkt->key_agreement_info->ephem_key,newkey))
	{
	GOSTerr(GOST_F_MAKE_RFC4490_KEYTRANSPORT_2001,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);
	EVP_PKEY_free(newkey);
	return gkt;
	memerr:
	GOSTerr(GOST_F_MAKE_RFC4490_KEYTRANSPORT_2001,
	GOST_R_MALLOC_FAILURE);
	err:
	GOST_KEY_TRANSPORT_free(gkt);
	return NULL;
	}

	/*
	* EVP_PKEY_METHOD callback encrypt
	* Implementation of GOST2001 key transport, cryptopo variation
	*/

	int pkey_GOST01cp_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);
	unsigned char ukm[8];
	int ret=0;
	if (RAND_bytes(ukm,8)<=0)
	{
	GOSTerr(GOST_F_PKEY_GOST01CP_ENCRYPT,
	GOST_R_RANDOM_GENERATOR_FAILURE);
	return 0;
	}

	if (!(gkt=make_rfc4490_keytransport_2001(pubk,gost_get_priv_key(data->eph_seckey),key, key_len,ukm,8)))
	{
	goto err;
	}
	if ((*out_len = i2d_GOST_KEY_TRANSPORT(gkt,&out))>0) ret =1;
	GOST_KEY_TRANSPORT_free(gkt);
	return ret;
	err:
	GOST_KEY_TRANSPORT_free(gkt);
	return -1;
	}
	/* Public, because it would be needed in SSL implementation */
	int decrypt_rfc4490_shared_key_2001(EVP_PKEY priv,GOST_KEY_TRANSPORT gkt,
	unsigned char *key_buf,int key_buf_len)
	{
	unsigned char wrappedKey[44];
	unsigned char sharedKey[32];
	gost_ctx ctx;
	const struct gost_cipher_info *param=NULL;
	EVP_PKEY *eph_key=NULL;

	eph_key = X509_PUBKEY_get(gkt->key_agreement_info->ephem_key);
	param = get_encryption_params(gkt->key_agreement_info->cipher);
	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);
	VKO_compute_key(sharedKey,32,EC_KEY_get0_public_key(EVP_PKEY_get0(eph_key)),
	EVP_PKEY_get0(priv),wrappedKey);
	if (!keyUnwrapCryptoPro(&ctx,sharedKey,wrappedKey,key_buf))
	{
	GOSTerr(GOST_F_PKCS7_GOST94CP_KEY_TRANSPORT_DECRYPT,
	GOST_R_ERROR_COMPUTING_SHARED_KEY);
	goto err;
	}

	EVP_PKEY_free(eph_key);
	return 32;
	err:
	EVP_PKEY_free(eph_key);
	return -1;
	}
	/*
	* EVP_PKEY_METHOD callback decrypt
	* Implementation of GOST2001 key transport, cryptopo variation
	*/
	int pkey_GOST01cp_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;

	if (!key)
	{
	*key_len = 32;
	return 1;
	}
	gkt = d2i_GOST_KEY_TRANSPORT(NULL,(const unsigned char **)&p,
	in_len);
	if (!gkt)
	{
	GOSTerr(GOST_F_PKCS7_GOST94CP_KEY_TRANSPORT_DECRYPT,GOST_R_ERROR_PARSING_KEY_TRANSPORT_INFO);
	return -1;
	}
	ret = decrypt_rfc4490_shared_key_2001(priv,gkt,key,*key_len);
	GOST_KEY_TRANSPORT_free(gkt);
	return ret;
	}