In random_add_noise, put the hashed noise into the pool, not the raw noise

random_add_noise calls SHATransform for every 64 octets of incoming noise,
yet instead of xor'ing the hashed noise into the pool it instead only xor'ed
20 octets of the raw noise in each iteration. This effectively reduced the
amount of new entropy entering the pool.

sshrand.c

@@ -240,7 +240,7 @@ void random_add_noise(void *noise, int length)
 	length -= HASHINPUT - pool.incomingpos;
 	SHATransform((word32 *) pool.incoming, (word32 *) pool.incomingb);
 	for (i = 0; i < HASHSIZE; i++) {
-	    pool.pool[pool.poolpos++] ^= pool.incomingb[i];
+	    pool.pool[pool.poolpos++] ^= pool.incoming[i];
 	    if (pool.poolpos >= POOLSIZE)
 		pool.poolpos = 0;
 	}