int RAND_DRBG_set(RAND_DRBG *drbg, int type, unsigned int flags);
int RAND_DRBG_instantiate(RAND_DRBG *drbg,
const unsigned char *pers, size_t perslen);
int RAND_DRBG_set(RAND_DRBG *drbg, int type, unsigned int flags);
int RAND_DRBG_instantiate(RAND_DRBG *drbg,
const unsigned char *pers, size_t perslen);