Using the OpenSSH known_hosts File

Tectia client tools for z/OS supports also the OpenSSH-style known_hosts file that contains the public key data of known server hosts, and reads the file by default from the default location, from the user-specific file $HOME/.ssh/known_hosts or from the system-wide file /etc/ssh/ssh_known_hosts. Both hashed and plain-format host keys are supported.

In case you wish to define other files to be used for the known host keys, you can specify the files in the Connection Broker configuration file ssh-broker-config.xml by using the known-hosts element. Several file locations can be defined to be checked for known host keys, and the Connection Broker will read them in the order they are defined in the ssh-broker-config.xml file. Since the configuration file settings will override the default behavior, you need to define also the default locations of the OpenSSH-style known_hosts file, in case you want them all to be read. For example:

  <known-hosts path="/home/username/.ssh/known_hosts" />
  <known-hosts path="/etc/ssh/ssh_known_hosts" />
  <known-hosts path="/home/.ssh2/hostkeys" />
  <known-hosts path="/u/username/.ssh2/hostkeys" />

You can disable OpenSSH known_hosts file handling by defining an empty setting: known-hosts path="". After this, only the Tectia-related hostkey directories will be used.

The OpenSSH known_hosts file is never automatically updated by Tectia client tools for z/OS. New host keys are always stored in the Tectia $HOME/.ssh2/hostkeys directory or in the directory configured as the last one in ssh-broker-config.xml. See known-hosts for details.