emsa_pss_encode
ret = emsa_pss_encode(m, mlen, em, (modbits - 1), &emsize, gen_hash_type, mgf_hash_type, saltlen, forced_salt); EG(ret, err);
ATTRIBUTE_WARN_UNUSED_RET int emsa_pss_encode(const u8 *m, u32 mlen, u8 *em, u32 embits,