Here’s a cfengine bundle that I wrote for editing the sshd configuration file by passing an array with the parameters. Using an array is a very elegant way of defining the values to set. The bundle also restarts sshd after any changes are made, unless the no_restarts class is defined.
The first gist contains the edit_sshd bundle itself, together with the set_config_values bundle that actually performs the editing job (this should go into a library file, I have it in my personal version of cfengine_stdlib.cf). The second file is a sample bundle showing how to use edit_sshd.