diff options
Diffstat (limited to 'libjava/java/lang/reflect')
| -rw-r--r-- | libjava/java/lang/reflect/AccessibleObject.java | 146 | ||||
| -rw-r--r-- | libjava/java/lang/reflect/Member.java | 100 |
2 files changed, 173 insertions, 73 deletions
diff --git a/libjava/java/lang/reflect/AccessibleObject.java b/libjava/java/lang/reflect/AccessibleObject.java index 05c9efd..6bfc23a 100644 --- a/libjava/java/lang/reflect/AccessibleObject.java +++ b/libjava/java/lang/reflect/AccessibleObject.java @@ -1,5 +1,5 @@ /* java.lang.reflect.AccessibleObject - Copyright (C) 1998, 1999, 2000, 2001 Free Software Foundation, Inc. + Copyright (C) 2001 Free Software Foundation, Inc. This file is part of GNU Classpath. @@ -7,7 +7,7 @@ GNU Classpath is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. - + GNU Classpath 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 @@ -24,54 +24,146 @@ resulting executable to be covered by the GNU General Public License. This exception does not however invalidate any other reasons why the executable file might be covered by the GNU General Public License. */ - + package java.lang.reflect; /** + * This class is the superclass of various reflection classes, and + * allows sufficiently trusted code to bypass normal restrictions to + * do necessary things like invoke private methods outside of the + * class during Serialization. If you don't have a good reason + * to mess with this, don't try. Fortunately, there are adequate + * security checks before you can set a reflection object as accessible. + * * @author Tom Tromey <tromey@cygnus.com> - * @date December 12, 1998 - */ -/* Written using JDK 1.2 beta docs. - * Status: Believed complete and correct. + * @author Eric Blake <ebb9@email.byu.edu> + * @see Field + * @see Constructor + * @see Method + * @see ReflectPermission + * @since 1.2 + * @status updated to 1.4 */ - public class AccessibleObject { - protected AccessibleObject () + /** + * True if this object is marked accessible, which means the reflected + * object bypasses normal security checks. <em>NOTE</em>Don't try messing + * with this by reflection. You'll mess yourself up. + */ + // default visibility for use by inherited classes + boolean flag = false; + + /** + * Only the three reflection classes that extend this can create an + * accessible object. This is not serializable for security reasons. + */ + protected AccessibleObject() { - flag = false; } - public boolean isAccessible () + /** + * Return the accessibility status of this object. + * + * @return true if this object bypasses security checks + */ + public boolean isAccessible() { return flag; } - public static void setAccessible (AccessibleObject[] array, boolean flag) + /** + * Convenience method to set the flag on a number of objects with a single + * security check. If a security manager exists, it is checked for + * <code>ReflectPermission("suppressAccessChecks")</code>.<p> + * + * If <code>flag</code> is true, and the initial security check succeeds, + * this can still fail if a forbidden object is encountered, leaving the + * array half-modified. At the moment, the forbidden members are:<br> + * <ul> + * <li>Any Constructor for java.lang.Class</li> + * <li>Any AccessibleObject for java.lang.reflect.AccessibleObject + * (this is not specified by Sun, but it closes a big security hole + * where you can use reflection to bypass the security checks that + * reflection is supposed to provide)</li> + * </ul> + * (Sun has not specified others, but good candidates might include + * ClassLoader, String, and such. However, the more checks we do, the + * slower this method gets). + * + * @param array the array of accessible objects + * @param flag the desired state of accessibility, true to bypass security + * @throws NullPointerException if array is null + * @throws SecurityException if the request is denied + * @see SecurityManager#checkPermission(java.security.Permission) + * @see RuntimePermission + */ + public static void setAccessible(AccessibleObject[] array, boolean flag) { - checkPermission (); - // FIXME: check for invalid changes in the loop. - // For instance, can't set this flag to true for a Constructor for - // Class (example from the manual). - for (int i = 0; i < array.length; ++i) - array[i].flag = flag; + checkPermission(); + for (int i = 0; i < array.length; i++) + array[i].secureSetAccessible(flag); } - public void setAccessible (boolean flag) + /** + * Sets the accessibility flag for this reflection object. If a security + * manager exists, it is checked for + * <code>ReflectPermission("suppressAccessChecks")</code>.<p> + * + * If <code>flag</code> is true, and the initial security check succeeds, + * this will still fail for a forbidden object. At the moment, the + * forbidden members are:<br> + * <ul> + * <li>Any Constructor for java.lang.Class</li> + * <li>Any AccessibleObject for java.lang.reflect.AccessibleObject + * (this is not specified by Sun, but it closes a big security hole + * where you can use reflection to bypass the security checks that + * reflection is supposed to provide)</li> + * </ul> + * (Sun has not specified others, but good candidates might include + * ClassLoader, String, and such. However, the more checks we do, the + * slower this method gets). + * + * @param flag the desired state of accessibility, true to bypass security + * @throws NullPointerException if array is null + * @throws SecurityException if the request is denied + * @see SecurityManager#checkPermission(java.security.Permission) + * @see RuntimePermission + */ + public void setAccessible(boolean flag) { - checkPermission (); - // FIXME: check for invalid changes. - // For instance, can't set this flag to true for a Constructor for - // Class (example from the manual). - this.flag = flag; + checkPermission(); + secureSetAccessible(flag); } - private static final void checkPermission () + /** + * Performs the specified security check, for + * <code>ReflectPermission("suppressAccessChecks")</code>. + * + * @throws SecurityException if permission is denied + */ + private static final void checkPermission() { SecurityManager sm = System.getSecurityManager(); if (sm != null) - sm.checkPermission (new ReflectPermission ("suppressAccessChecks")); + sm.checkPermission(new ReflectPermission("suppressAccessChecks")); } - private boolean flag; + /** + * Performs the actual accessibility change, this must always be invoked + * after calling checkPermission. + * + * @param flag the desired status + * @throws SecurityException if flag is true and this is one of the + * forbidden members mentioned in {@link setAccessible(boolean)}. + */ + private final void secureSetAccessible(boolean flag) + { + if (flag && + ((this instanceof Constructor + && ((Constructor) this).getDeclaringClass() == Class.class) + || ((Member) this).getDeclaringClass() == AccessibleObject.class)) + throw new SecurityException("Cannot make object accessible: " + this); + this.flag = flag; + } } diff --git a/libjava/java/lang/reflect/Member.java b/libjava/java/lang/reflect/Member.java index d76cdda..1c313b0 100644 --- a/libjava/java/lang/reflect/Member.java +++ b/libjava/java/lang/reflect/Member.java @@ -1,4 +1,4 @@ -/* java.lang.reflect.Member +/* java.lang.reflect.Member - common query methods in reflection Copyright (C) 1998, 1999, 2001 Free Software Foundation, Inc. This file is part of GNU Classpath. @@ -7,7 +7,7 @@ GNU Classpath is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. - + GNU Classpath 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 @@ -27,55 +27,63 @@ executable file might be covered by the GNU General Public License. */ package java.lang.reflect; -/* Written using "Java Class Libraries", 2nd edition. - * Status: Believed complete and correct. - */ - /** - * Member is an interface that represents any member of a class. - * i.e. a field, a method or a constructor. - * You can get information about the declaring class, name or modifiers of - * the member with this interface. + * Member is an interface that represents any member of a class (field or + * method) or a constructor. You can get information about the declaring + * class, name or modifiers of the member with this interface. * - * @author John Keiser - * @author Per Bothner <bothner@cygnus.com> + * @author John Keiser + * @author Per Bothner <bothner@cygnus.com> + * @author Eric Blake <ebb9@email.byu.edu> + * @see Class + * @see Field + * @see Method + * @see Constructor + * @since 1.1 + * @status updated to 1.4 */ -public interface Member { - /** - * Represents all members, whether public, private, protected or - * package-protected. - * Used in java.lang.SecurityManager.checkMemberAccess() to determine the - * type of members to access. - */ - static final int DECLARED = 1; +public interface Member +{ + /** + * Represents all members, whether public, private, protected or + * package-protected, but only which are declared in this class. + * Used in SecurityManager.checkMemberAccess() to determine the + * type of members to access. + * @see SecurityManager#checkMemberAccess() + */ + int DECLARED = 1; - /** - * Represents public members only. Used inr - * java.lang.SecurityManager.checkMemberAccess() to determine the type of - * members to access. - */ - static final int PUBLIC = 0; + /** + * Represents public members only, but includes all inherited members. + * Used in SecurityManager.checkMemberAccess() to determine the type of + * members to access. + * @see SecurityManager#checkMemberAccess() + */ + int PUBLIC = 0; - /** - * Gets the class that declared this member. - * <STRONG>It is unclear whether this returns the class that actually - * syntactically declared the member, or the class where the - * <code>Member</code> object was gotten from.</STRONG> - * @return the class that declared this member. - */ - Class getDeclaringClass(); + /** + * Gets the class that declared this member. This is not the class where + * this method was called, or even the class where this Member object + * came to life, but the class that declares the member this represents. + * + * @return the class that declared this member + */ + Class getDeclaringClass(); - /** - * Gets the modifiers this member uses. Use the <code>Modifier</code> - * class to interpret the values. - * @see Modifier - * @return an integer representing the modifiers to this Member. - */ - int getModifiers(); + /** + * Gets the simple name of this member. This will be a valid Java + * identifier, with no qualification. + * + * @return the name of this member + */ + String getName(); - /** - * Gets the name of this member. - * @return the name of this member. - */ - String getName(); + /** + * Gets the modifiers this member uses. Use the <code>Modifier</code> + * class to interpret the values. + * + * @return an integer representing the modifiers to this Member + * @see Modifier + */ + int getModifiers(); } |