J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2005-2006 Sun Microsystems, Inc. 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. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | |
| 26 | package com.sun.script.javascript; |
| 27 | |
| 28 | import java.lang.reflect.*; |
| 29 | import static sun.security.util.SecurityConstants.*; |
| 30 | import sun.org.mozilla.javascript.internal.*; |
| 31 | |
| 32 | /** |
| 33 | * This wrap factory is used for security reasons. JSR 223 script |
| 34 | * engine interface and JavaScript engine classes are run as bootstrap |
| 35 | * classes. For example, java.lang.Class.forName method (when called without |
| 36 | * class loader) uses caller's class loader. This may be exploited by script |
| 37 | * authors to access classes otherwise not accessible. For example, |
| 38 | * classes in sun.* namespace are normally not accessible to untrusted |
| 39 | * code and hence should not be accessible to JavaScript run from |
| 40 | * untrusted code. |
| 41 | * |
| 42 | * @author A. Sundararajan |
| 43 | * @since 1.6 |
| 44 | */ |
| 45 | final class RhinoWrapFactory extends WrapFactory { |
| 46 | private RhinoWrapFactory() {} |
| 47 | private static RhinoWrapFactory theInstance; |
| 48 | |
| 49 | static synchronized WrapFactory getInstance() { |
| 50 | if (theInstance == null) { |
| 51 | theInstance = new RhinoWrapFactory(); |
| 52 | } |
| 53 | return theInstance; |
| 54 | } |
| 55 | |
| 56 | // We use instance of this class to wrap security sensitive |
| 57 | // Java object. Please refer below. |
| 58 | private static class RhinoJavaObject extends NativeJavaObject { |
| 59 | RhinoJavaObject(Scriptable scope, Object obj, Class type) { |
| 60 | // we pass 'null' to object. NativeJavaObject uses |
| 61 | // passed 'type' to reflect fields and methods when |
| 62 | // object is null. |
| 63 | super(scope, null, type); |
| 64 | |
| 65 | // Now, we set actual object. 'javaObject' is protected |
| 66 | // field of NativeJavaObject. |
| 67 | javaObject = obj; |
| 68 | } |
| 69 | } |
| 70 | |
| 71 | public Scriptable wrapAsJavaObject(Context cx, Scriptable scope, |
| 72 | Object javaObject, Class staticType) { |
| 73 | SecurityManager sm = System.getSecurityManager(); |
| 74 | ClassShutter classShutter = RhinoClassShutter.getInstance(); |
| 75 | if (javaObject instanceof ClassLoader) { |
| 76 | // Check with Security Manager whether we can expose a |
| 77 | // ClassLoader... |
| 78 | if (sm != null) { |
| 79 | sm.checkPermission(GET_CLASSLOADER_PERMISSION); |
| 80 | } |
| 81 | // if we fall through here, check permission succeeded. |
| 82 | return super.wrapAsJavaObject(cx, scope, javaObject, staticType); |
| 83 | } else { |
| 84 | String name = null; |
| 85 | if (javaObject instanceof Class) { |
| 86 | name = ((Class)javaObject).getName(); |
| 87 | } else if (javaObject instanceof Member) { |
| 88 | Member member = (Member) javaObject; |
| 89 | // Check member access. Don't allow reflective access to |
| 90 | // non-public members. Note that we can't call checkMemberAccess |
| 91 | // because that expects exact stack depth! |
| 92 | if (sm != null && !Modifier.isPublic(member.getModifiers())) { |
| 93 | return null; |
| 94 | } |
| 95 | name = member.getDeclaringClass().getName(); |
| 96 | } |
| 97 | // Now, make sure that no ClassShutter prevented Class or Member |
| 98 | // of it is accessed reflectively. Note that ClassShutter may |
| 99 | // prevent access to a class, even though SecurityManager permit. |
| 100 | if (name != null) { |
| 101 | if (!classShutter.visibleToScripts(name)) { |
| 102 | return null; |
| 103 | } else { |
| 104 | return super.wrapAsJavaObject(cx, scope, javaObject, staticType); |
| 105 | } |
| 106 | } |
| 107 | } |
| 108 | |
| 109 | // we have got some non-reflective object. |
| 110 | Class dynamicType = javaObject.getClass(); |
| 111 | String name = dynamicType.getName(); |
| 112 | if (!classShutter.visibleToScripts(name)) { |
| 113 | // Object of some sensitive class (such as sun.net.www.* |
| 114 | // objects returned from public method of java.net.URL class. |
| 115 | // We expose this object as though it is an object of some |
| 116 | // super class that is safe for access. |
| 117 | |
| 118 | Class type = null; |
| 119 | |
| 120 | // Whenever a Java Object is wrapped, we are passed with a |
| 121 | // staticType which is the type found from environment. For |
| 122 | // example, method return type known from signature. The dynamic |
| 123 | // type would be the actual Class of the actual returned object. |
| 124 | // If the staticType is an interface, we just use that type. |
| 125 | if (staticType != null && staticType.isInterface()) { |
| 126 | type = staticType; |
| 127 | } else { |
| 128 | // dynamicType is always a class type and never an interface. |
| 129 | // find an accessible super class of the dynamic type. |
| 130 | while (dynamicType != null) { |
| 131 | dynamicType = dynamicType.getSuperclass(); |
| 132 | name = dynamicType.getName(); |
| 133 | if (classShutter.visibleToScripts(name)) { |
| 134 | type = dynamicType; break; |
| 135 | } |
| 136 | } |
| 137 | // atleast java.lang.Object has to be accessible. So, when |
| 138 | // we reach here, type variable should not be null. |
| 139 | assert type != null: |
| 140 | "even java.lang.Object is not accessible?"; |
| 141 | } |
| 142 | // create custom wrapper with the 'safe' type. |
| 143 | return new RhinoJavaObject(scope, javaObject, type); |
| 144 | } else { |
| 145 | return super.wrapAsJavaObject(cx, scope, javaObject, staticType); |
| 146 | } |
| 147 | } |
| 148 | } |