ssh-keysign(8) on macOS
The text 2c25ff01f7ae, as Mac OS X 10.5.2, Mac OS X 10.5.1, Mac OS X 10.5, Mac OS X 10.4.11.x86, Mac OS X 10.4.11.ppc, Mac OS X 10.4.10.x86, Mac OS X 10.4.10.ppc, Mac OS X 10.4.9.x86, Mac OS X 10.4.9.ppc shipped it.
ssh helper program for host-based authentication