1 /*
   2  * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package java.dyn;
  27 
  28 import java.security.*;
  29 import java.util.Enumeration;
  30 import java.util.Hashtable;
  31 import java.util.StringTokenizer;
  32 
  33 /**
  34  * This class is for managing runtime permission checking for
  35  * operations performed by methods in the {@link Linkage} class.
  36  * Like a {@link RuntimePermission}, on which it is modeled,
  37  * a {@code LinkagePermission} contains a target name but
  38  * no actions list; you either have the named permission
  39  * or you don't.
  40  * <p>
  41  * The following table lists all the possible {@code LinkagePermission} target names,
  42  * and for each provides a description of what the permission allows
  43  * and a discussion of the risks of granting code the permission.
  44  * <p>
  45  *
  46  * <table border=1 cellpadding=5 summary="permission target name,
  47  *  what the target allows,and associated risks">
  48  * <tr>
  49  * <th>Permission Target Name</th>
  50  * <th>What the Permission Allows</th>
  51  * <th>Risks of Allowing this Permission</th>
  52  * </tr>
  53  *
  54  * <tr>
  55  *   <td>registerBootstrapMethod.{class name}</td>
  56  *   <td>Specifying a bootstrap method for {@code invokedynamic} instructions within a class of the given name</td>
  57  *   <td>An attacker could attempt to attach a bootstrap method to a class which
  58  *       has just been loaded, thus gaining control of its {@code invokedynamic} calls.</td>
  59  * </tr>
  60  *
  61  * <tr>
  62  *   <td>invalidateAll</td>
  63  *   <td>Force the relinking of invokedynamic call sites everywhere.</td>
  64  *   <td>This could allow an attacker to slow down the system,
  65  *       or perhaps expose timing bugs in a dynamic language implementations,
  66  *       by forcing redundant relinking operations.</td>
  67  * </tr>
  68  *
  69  *
  70  * <tr>
  71  *   <td>invalidateCallerClass.{class name}</td>
  72  *   <td>Force the relinking of invokedynamic call sites in the given class.</td>
  73  *   <td>See {@code invalidateAll}.</td>
  74  * </tr>
  75  * </table>
  76  *
  77  * @see java.security.RuntimePermission
  78  * @see java.lang.SecurityManager
  79  *
  80  * @author John Rose, JSR 292 EG
  81  */
  82 
  83 public final class LinkagePermission extends BasicPermission {
  84     private static final long serialVersionUID = 292L;
  85 
  86     /**
  87      * Create a new LinkagePermission with the given name.
  88      * The name is the symbolic name of the LinkagePermission, such as
  89      * "registerBootstrapMethod", "invalidateCallerClass.*", etc. An asterisk
  90      * may appear at the end of the name, following a ".", or by itself, to
  91      * signify a wildcard match.
  92      *
  93      * @param name the name of the LinkagePermission
  94      */
  95     public LinkagePermission(String name) {
  96         super(name);
  97     }
  98 
  99     /**
 100      * Create a new LinkagePermission with the given name on the given class.
 101      * Equivalent to {@code LinkagePermission(name+"."+clazz.getName())}.
 102      *
 103      * @param name the name of the LinkagePermission
 104      * @param clazz the class affected by the permission
 105      */
 106     public LinkagePermission(String name, Class<?> clazz) {
 107         super(name + "." + clazz.getName());
 108     }
 109 }