PKCS8_add_keyusage
LCRYPTO_USED(PKCS8_add_keyusage);
LCRYPTO_ALIAS(PKCS8_add_keyusage);
if (key_usage && !PKCS8_add_keyusage(p8, key_usage))
int PKCS8_add_keyusage(PKCS8_PRIV_KEY_INFO *p8, int usage);