in src/rand.c [133:141]
void RAND_clean(csprng *rng) { /* kill internal state */ int i; rng->pool_ptr=rng->rndptr=0; for (i=0; i<32; i++) rng->pool[i]=0; for (i=0; i<NK; i++) rng->ira[i]=0; rng->borrow=0; }