Shawn, thanks for the detailed explanation. Rather than faking the system into thinking it's running RHEL6, would it be possible to update the oval definitions to include CentOS as an applicable platform?

On Fri, Aug 15, 2014 at 1:10 PM, Shawn Wells <> wrote:
On 8/14/14, 5:25 PM, Jeremiah Jahn wrote:
> I'm using it for SL6. The problem is in openscap-cpe-oval.xml. The
> test for release is searching on RedHat only.
> I've changed mine to the following: notice the (redhat|sl) on the
> second line. You should be able to change it to whatever the
> centos-release rpm says. I can't remember right now if SSG is where I
> got the original xml file, or if it's the one from open-scap. It's
> very possible that you'll have to make sure that you'll have to alter
> the ssg-rhel6-cpe-dictionary.xml to point to your altered cpe-oval
> file. I've attached them just incase, but it took some tweaking.
> <rpminfo_state id="" version="1"
> xmlns="">
>                   <name operation="pattern match">^(redhat|sl)-release</name>
>                   <version operation="pattern match">^6[^\d]</version>
>             </rpminfo_state>

To illustrate how CPE works, as part of Greg's question....

Step 1: In your OVAL check, you define which platforms the check is
written for. This is done by the <affected> stanzas, such as:

>       <affected family="unix">
>         <platform>Red Hat Enterprise Linux 6</platform>
>       </affected>

Step 2: When an SCAP interpreter parses each OVAL rule, it will parse
the <affected> tag above. For each <platform> listed, it will find the
associated <cpi-item> to find what <check> needs to be ran. This will
tell the SCAP interpreter if the OVAL rule is applicable for the system
being scanned.

For example, from SSG's CPE dictionary:

>       <cpe-item name="cpe:/o:redhat:enterprise_linux:6">
>             <title xml:lang="en-us">Red Hat Enterprise Linux 6</title>
>             <!-- the check references an OVAL file that contains an inventory definition -->
>             <check system="" href="filename">installed_OS_is_rhel6</check>
>       </cpe-item>

In this case, if the <platform> tag matches the cpe-item/title, then the
cpe-item/check will be ran. In the case of "Red Hat Enterprise Linux 6"
the OVAL check "installed_OS_is_rhel6" will be ran.

The installed_OS_is_rhel6 OVAL check queries the system to see if the
redhat-release-{server workstation}-6 RPM is installed, for example:
>   <linux:rpminfo_test check="all" check_existence="at_least_one_exists" comment="redhat-release-server is version 6" id="test_rhel_server" version="1">
>     <linux:object object_ref="obj_rhel_server" />
>     <linux:state state_ref="state_rhel_server" />
>   </linux:rpminfo_test>
>   <linux:rpminfo_state id="state_rhel_server" version="1">
>     <linux:version operation="pattern match">^6\.\d+$</linux:version>
>   </linux:rpminfo_state>
>   <linux:rpminfo_object id="obj_rhel_server" version="1">
>     <linux:name>redhat-release-server</linux:name>
>   </linux:rpminfo_object>

If the the check passes, the SCAP interpreter knows the particular OVAL
rule is applicable to the system, executes the probes, and you get a
pass/fail result. If the installed_OS_is_rhel6 check fails, the OVAL
rule will be marked as "Not Applicable."

For users running derivative operating systems (CentOS, Scientific...)
you can edit your CPE dictionary's regex like Jeremiah outlined. This
will "fake" the system into thinking it's running RHEL6 and allow the
check to be ran.