Java tutorial
/* * Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package java.awt; import java.security.BasicPermission; /** * This class is for AWT permissions. * An {@code AWTPermission} contains a target name but * no actions list; you either have the named permission * or you don't. * * <P> * The target name is the name of the AWT permission (see below). The naming * convention follows the hierarchical property naming convention. * Also, an asterisk could be used to represent all AWT permissions. * * <P> * The following table lists all the possible {@code AWTPermission} * target names, and for each provides a description of what the * permission allows and a discussion of the risks of granting code * the permission. * * <table class="striped"> * <caption>AWTPermission target names, descriptions, and associated risks * </caption> * <thead> * <tr> * <th scope="col">Permission Target Name * <th scope="col">What the Permission Allows * <th scope="col">Risks of Allowing this Permission * </thead> * <tbody> * <tr> * <th scope="row">accessClipboard * <td>Posting and retrieval of information to and from the AWT clipboard * <td>This would allow malfeasant code to share potentially sensitive or * confidential information. * <tr> * <th scope="row">accessEventQueue * <td>Access to the AWT event queue * <td>After retrieving the AWT event queue, malicious code may peek at and * even remove existing events from its event queue, as well as post bogus * events which may purposefully cause the application or applet to * misbehave in an insecure manner. * <tr> * <th scope="row">accessSystemTray * <td>Access to the AWT SystemTray instance * <td>This would allow malicious code to add tray icons to the system tray. * First, such an icon may look like the icon of some known application * (such as a firewall or anti-virus) and order a user to do something * unsafe (with help of balloon messages). Second, the system tray may be * glutted with tray icons so that no one could add a tray icon anymore. * <tr> * <th scope="row">createRobot * <td>Create java.awt.Robot objects * <td>The java.awt.Robot object allows code to generate native-level mouse * and keyboard events as well as read the screen. It could allow malicious * code to control the system, run other programs, read the display, and * deny mouse and keyboard access to the user. * <tr> * <th scope="row">fullScreenExclusive * <td>Enter full-screen exclusive mode * <td>Entering full-screen exclusive mode allows direct access to low-level * graphics card memory. This could be used to spoof the system, since the * program is in direct control of rendering. Depending on the * implementation, the security warning may not be shown for the windows * used to enter the full-screen exclusive mode (assuming that the * {@code fullScreenExclusive} permission has been granted to this * application). Note that this behavior does not mean that the * {@code showWindowWithoutWarningBanner} permission will be automatically * granted to the application which has the {@code fullScreenExclusive} * permission: non-full-screen windows will continue to be shown with the * security warning. * <tr> * <th scope="row">listenToAllAWTEvents * <td>Listen to all AWT events, system-wide * <td>After adding an AWT event listener, malicious code may scan all AWT * events dispatched in the system, allowing it to read all user input (such * as passwords). Each AWT event listener is called from within the context * of that event queue's EventDispatchThread, so if the accessEventQueue * permission is also enabled, malicious code could modify the contents of * AWT event queues system-wide, causing the application or applet to * misbehave in an insecure manner. * <tr> * <th scope="row">readDisplayPixels * <td>Readback of pixels from the display screen * <td>Interfaces such as the java.awt.Composite interface or the * java.awt.Robot class allow arbitrary code to examine pixels on the * display enable malicious code to snoop on the activities of the user. * <tr> * <th scope="row">replaceKeyboardFocusManager * <td>Sets the {@code KeyboardFocusManager} for a particular thread. * <td>When {@code SecurityManager} is installed, the invoking thread must * be granted this permission in order to replace the current * {@code KeyboardFocusManager}. If permission is not granted, a * {@code SecurityException} will be thrown. * <tr> * <th scope="row">setAppletStub * <td>Setting the stub which implements Applet container services * <td>Malicious code could set an applet's stub and result in unexpected * behavior or denial of service to an applet. * <tr> * <th scope="row">setWindowAlwaysOnTop * <td>Setting always-on-top property of the window: * {@link Window#setAlwaysOnTop} * <td>The malicious window might make itself look and behave like a real * full desktop, so that information entered by the unsuspecting user is * captured and subsequently misused * <tr> * <th scope="row">showWindowWithoutWarningBanner * <td>Display of a window without also displaying a banner warning that the * window was created by an applet * <td>Without this warning, an applet may pop up windows without the user * knowing that they belong to an applet. Since users may make * security-sensitive decisions based on whether or not the window belongs * to an applet (entering a username and password into a dialog box, for * example), disabling this warning banner may allow applets to trick the * user into entering such information. * <tr> * <th scope="row">toolkitModality * <td>Creating {@link Dialog.ModalityType#TOOLKIT_MODAL TOOLKIT_MODAL} * dialogs and setting the * {@link Dialog.ModalExclusionType#TOOLKIT_EXCLUDE TOOLKIT_EXCLUDE} window * property. * <td>When a toolkit-modal dialog is shown from an applet, it blocks all * other applets in the browser. When launching applications from Java Web * Start, its windows (such as the security dialog) may also be blocked by * toolkit-modal dialogs, shown from these applications. * <tr> * <th scope="row">watchMousePointer * <td>Getting the information about the mouse pointer position at any time * <td>Constantly watching the mouse pointer, an applet can make guesses * about what the user is doing, i.e. moving the mouse to the lower left * corner of the screen most likely means that the user is about to launch * an application. If a virtual keypad is used so that keyboard is emulated * using the mouse, an applet may guess what is being typed. * </tbody> * </table> * * @see java.security.BasicPermission * @see java.security.Permission * @see java.security.Permissions * @see java.security.PermissionCollection * @see java.lang.SecurityManager * * @author Marianne Mueller * @author Roland Schemers */ public final class AWTPermission extends BasicPermission { /** use serialVersionUID from the Java 2 platform for interoperability */ private static final long serialVersionUID = 8890392402588814465L; /** * Creates a new {@code AWTPermission} with the specified name. * The name is the symbolic name of the {@code AWTPermission}, * such as "topLevelWindow", "systemClipboard", etc. An asterisk * may be used to indicate all AWT permissions. * * @param name the name of the AWTPermission * * @throws NullPointerException if {@code name} is {@code null}. * @throws IllegalArgumentException if {@code name} is empty. */ public AWTPermission(String name) { super(name); } /** * Creates a new {@code AWTPermission} object with the specified name. * The name is the symbolic name of the {@code AWTPermission}, and the * actions string is currently unused and should be {@code null}. * * @param name the name of the {@code AWTPermission} * @param actions should be {@code null} * * @throws NullPointerException if {@code name} is {@code null}. * @throws IllegalArgumentException if {@code name} is empty. */ public AWTPermission(String name, String actions) { super(name, actions); } }