ref: a3c75553b4c50247ce22a4da4d2a87c10d5b0835
dir: /sys/src/libsec/port/prng.c/
#include "os.h"
#include <libsec.h>
//
//  just use the libc prng to fill a buffer
//
void
prng(uchar *p, int n)
{
	uchar *e;
	for(e = p+n; p < e; p++)
		*p = rand();
}