trait BasicAuthenticator {

  def basicUserAuthenticator(username: String, password: String)(implicit ec: ExecutionContext): AuthMagnet[UserPass] = {
    def validateUser(userPass: Option[UserPass]): Option[UserPass] =
      for {
        u <- userPass if u.user == username && u.pass == password
      } yield u

    def authenticator(userPass: Option[UserPass]): Future[Option[UserPass]] =
      Future(validateUser(userPass))

    BasicAuth(authenticator _, realm = "Private API")
  }
}