Lighttpd

At the moment, it is possible to require client certificates from a trusted CA. However, there appears to be no way to require a specific certificate for authorization control.

With the attached patch, it is possible to use $HTTP["remoteuser"] in logic decisions by setting:
ssl.verifyclient.username = "SSL_CLIENT_S_DN_CN"
ssl.verifyclient.exportcert = "enable"

Example syntax could be:
$HTTP["url"] =~ "^/cert_required" {
$HTTP["remoteuser"] !~ "my cert CN" {
url.access-deny = ( "" )
}
}