Before upgrading to Coldfusion 10, we used Coldfusion 7 and Apache 2.0 with the Apache CGI environment variables. We had to use a work around to get access to the same information in Coldfusion 10.
The code that I had to use for Coldfusion 10 with Apache 2.2 to pull the same information as the CGI variables:
<cfset x509=GetPageContext().getRequest().getAttribute("javax.servlet.reques t.X509Certificate")>
<cfset CERT_ISSUER=x509[1].getIssuerDN().getName()>
<cfset CERT_SUBJECT_DN=x509[1].getSubjectDN().getName()>
This should help out when you are dealing with X509/PKI certificates.