3.2. The RHN SSL Maintenance Tool

Red Hat Network provides a command line tool to ease management of your secure infrastructure: the RHN SSL Maintenance Tool, commonly known by its command rhn-ssl-tool. This tool is available as part of the rhns-certs-tools package. This package can be found within the software channels for the latest RHN Proxy Server and RHN Satellite Server (as well as the RHN Satellite Server ISO). RHN SSL Maintenance Tool enables you to generate your own Certificate Authority SSL key pair, as well as Web server SSL key sets (sometimes called key pairs).
This tool is only a build tool. It generates all of the SSL keys and certificates that are required. It also packages the files in RPM format for quick distribution and installation on all client machines. It does not deploy them, however. That is left to the administrator, or in many cases, automated by the RHN Satellite Server.

Note

The rhns-certs-tools, which contains rhn-ssl-tool, can be installed and run on any current Red Hat Enterprise Linux system with minimal requirements. This is offered as a convenience for administrators who wish to manage their SSL infrastructure from their workstation or another system other than their RHN Server(s).
Here are the cases in which the tool is required:
  • When updating your CA public certificate - this is rare.
  • When installing an RHN Proxy Server version 3.6 or later that connects to the central RHN Servers as its top-level service - the hosted service, for security reasons, cannot be a repository for your CA SSL key and certificate, which is private to your organization.
  • When reconfiguring your RHN infrastructure to use SSL where it previously did not.
  • When adding RHN Proxy Servers of versions prior to 3.6 into your RHN infrastructure.
  • When adding multiple RHN Satellite Servers to your RHN infrastructure - consult with a Red Hat representative for instructions regarding this.
Here are the cases in which the tool is not required:
  • During installation of an RHN Satellite Server - all SSL settings are configured during the installation process. The SSL keys and certificate are built and deployed automatically.
  • During installation of an RHN Proxy Server version 3.6 or later if connected to an RHN Satellite Server version 3.6 or later as its top-level service - the RHN Satellite Server contains all of the SSL information needed to configure, build and deploy the RHN Proxy Server's SSL keys and certificates.
The installation procedures of both the RHN Satellite Server and the RHN Proxy Server ensure the CA SSL public certificate is deployed to the /pub directory of each server. This public certificate is used by the client systems to connect to the RHN Server. Refer to Section 3.3, “Deploying the CA SSL Public Certificate to Clients” for more information.
In short, if your organization's RHN infrastructure deploys the latest version of RHN Satellite Server as its top-level service, you will likely have little need to use the tool. Otherwise, become familiar with its usage.

3.2.1. SSL Generation Explained

The primary benefits of using the RHN SSL Maintenance Tool are security, flexibility, and portability. Security is achieved through the creation of distinct Web server SSL keys and certificates for each RHN server, all signed by a single Certificate Authority SSL key pair created by your organization. Flexibility is supplied by the tool's ability to work on any machine that has the rhns-certs-tools package installed. Portability exists in a build structure that can be stored anywhere for safe keeping and then installed wherever the need arises.
Again, if your infrastructure's top-level RHN Server is the most current RHN Satellite Server, the most you may have to do is restore your ssl-build tree from an archive to the /root directory and utilize the configuration tools provided within the RHN Satellite Server's website.
To make the best use of the RHN SSL Maintenance Tool, complete the following high-level tasks in roughly this order. Refer to the remaining sections for the required details:
  1. Install the rhns-certs-tools package on a system within your organization, perhaps but not necessarily the RHN Satellite Server or RHN Proxy Server.
  2. Create a single Certificate Authority SSL key pair for your organization and install the resulting RPM or public certificate on all client systems.
  3. Create a Web server SSL key set for each of the Proxies and Satellites to be deployed and install the resulting RPMs on the RHN Servers, restarting the httpd service afterwards:
     /sbin/service httpd restart 
  4. Archive the SSL build tree - consisting of the primary build directory and all subdirectories and files - to removable media, such as a floppy disk. (Disk space requirements are insignificant.)
  5. Verify and then store that archive in a safe location, such as the one described for backups in the Additional Requirements sections of either the Proxy or Satellite installation guide.
  6. Record and secure the CA password for future use.
  7. Delete the build tree from the build system for security purposes, but only once the entire RHN infrastructure is in place and configured.
  8. When additional Web server SSL key sets are needed, restore the build tree on a system running the RHN SSL Maintenance Tool and repeat steps 3 through 7.