# File common/lib/symbiosis/domain/ssl.rb, line 252
    def ssl_find_matching_certificate_and_key
      #
      # Find the certificates and keys
      #
      certificate_files, key_files = self.ssl_available_files

      return nil if certificate_files.empty? or key_files.empty?

      #
      # Test each certificate...
      certificate_files.each do |cert_fn|
        cert = OpenSSL::X509::Certificate.new(File.read(cert_fn))
        #
        # ...with each key
        key_files.each do |key_fn|
          key = OpenSSL::PKey::RSA.new(File.read(key_fn))
          #
          # This tests the private key, and returns the current certificate and
          # key if they verify.
          return [cert_fn, key_fn] if cert.check_private_key(key)
        end
      end

      #
      # Return nil if no matching keys and certs are found
      return nil
    end