_mgf1
ret = _mgf1(h, hlen, dbmask, dblen, mgf_hash_type); EG(ret, err);
ret = _mgf1(seed, hlen, dbmask, khlen, mgf_hash_type); EG(ret, err);
ret = _mgf1(maskeddb, (u16)khlen, seedmask, hlen, mgf_hash_type); EG(ret, err);
ret = _mgf1(maskeddb, (u16)khlen, seedmask, hlen, mgf_hash_type); EG(ret, err);
ret = _mgf1(seed, hlen, dbmask, khlen, mgf_hash_type); EG(ret, err);
ret = _mgf1(h, hlen, dbmask, dblen, mgf_hash_type); EG(ret, err);