/* Swap two buffers in RAM. They must be disjoint.  */
static void bufswap(void *b1, void *b2, size_t len)
/* Swap two buffers in RAM. They must be disjoint.  */
static void bufswap(void *b1, void *b2, size_t len)
{
	size_t u;
	unsigned char *buf1, *buf2;
	buf1 = b1;
	buf2 = b2;
	for (u = 0; u < len; u ++) {
		unsigned w;
		w = buf1[u];
		buf1[u] = buf2[u];
		buf2[u] = w;
	}
}