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);

int decrypt_rfc4490_shared_key_2001(EVP_PKEY *priv,
                                    GOST_KEY_TRANSPORT *gkt,
                                    unsigned char *key_buf,
                                    int key_buf_len) ;