fix linter issues

Signed-off-by: Dominik Richter <dominik.richter@gmail.com>
enforce access permissions to /etc/ssh

Signed-off-by: Dominik Richter <dominik.richter@gmail.com>
feature: add cipher configuration for redhat and centos

Signed-off-by: Dominik Richter <dominik.richter@gmail.com>