authenticate

# File lib/webrick/httpauth/basicauth.rb, line 69
      def authenticate(req, res)
        unless basic_credentials = check_scheme(req)
          challenge(req, res)
        end
        userid, password = basic_credentials.unpack("m*")[0].split(":", 2)
        password ||= ""
        if userid.empty?
          error("user id was not given.")
          challenge(req, res)
        end
        unless encpass = @userdb.get_passwd(@realm, userid, @reload_db)
          error("%s: the user is not allowed.", userid)
          challenge(req, res)
        end
        if password.crypt(encpass) != encpass
          error("%s: password unmatch.", userid)
          challenge(req, res)
        end
        info("%s: authentication succeeded.", userid)
        req.user = userid
      end