====== Fetching SSH hostkeys without interaction ======

---- dataentry snipplet ----
snipplet_tags: ssh, ssh-keys
LastUpdate_dt: 2010-07-31
Contributors: Jan Schampera
----

Applies at least to ''openssh''.

To get the hostkeys for a server, and write them to ''known_hosts''-file (to avoid that yes/no query when the key isn't known), you can do:

<code>
ssh-keyscan -t rsa foo foo.example.com 1.2.3.4 >> ~/.ssh/known_host
</code>

This example queries the hostkeys for the very same machine, but under 3 different "names" (hostname, FQDN, IP) and redirects the output to the ''known_hosts''-file.

__**Notes:**__
  * if done blindly, the ''known_host''-file may grow very large. It might be wise to check for key existance first
  * if multiple keys for the same host exist in ''known_hosts'', the first one is taken (which might be an old or wrong one)