libtomcrypt(3) on Linux
The text 3c0f5bb951f6, as Debian 13 (Trixie), Debian 12 (Bookworm), Debian 11 (Bullseye), Debian 10 (Buster), Debian 9 (Stretch), Debian 8 (Jessie) shipped it. The page shows this text now.
public domain open source crypthographic toolkit