# File lib/mcollective/security/aes_security.rb, line 384
      def certname_from_certificate(cert)
        id = cert.subject
        if id.to_s =~ /^\/CN=([\w\.\-]+)/
          return $1
        else
          raise("Received a callerid in an unexpected format in an SSL certificate: '#{id}', ignoring")
        end
      end