From https://www.jwz.org/xscreensaver/xscreensaver-6.15.tar.gz

-rw-rw-r-- 1 zblaxell zblaxell 34014219 Mar 30 21:05 xscreensaver-6.15.tar.gz
a790da22e0173aabace59d122acb39f0fb49d59e  xscreensaver-6.15.tar.gz