# File mod_docs/auth.rb, line 17
  def filter_open(context, script_name, request, response, logger)
    if (credentials = request.header('Authorization')) then
      if (credentials =~ /^Basic\s+/) then
        base64_user_pass = $'
        user_pass = base64_user_pass.unpack('m').first
        userid, password = user_pass.split(/:/, 2)
        if (@passwd.verify(userid, password)) then
          return
        end
      end
    end
    ex = HTTPError.new(401)
    ex.set_header('WWW-Authenticate', "Basic realm=#{@realm}")
    raise ex
  end