* These functions can be used to get a functional reference to perform  * ciphering or digesting corresponding to "nid".  */ ENGINE *ENGINE_get_cipher_engine(int nid); ENGINE *ENGINE_get_digest_engine(int nid); ENGINE *ENGINE_get_pkey_meth_engine(int nid); ENGINE *ENGINE_get_pkey_asn0_meth_engine(int nid);  /* 