001 /*
002 * Copyright 1997-2006 Sun Microsystems, Inc. All Rights Reserved.
003 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
004 *
005 * This code is free software; you can redistribute it and/or modify it
006 * under the terms of the GNU General Public License version 2 only, as
007 * published by the Free Software Foundation. Sun designates this
008 * particular file as subject to the "Classpath" exception as provided
009 * by Sun in the LICENSE file that accompanied this code.
010 *
011 * This code is distributed in the hope that it will be useful, but WITHOUT
012 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
013 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
014 * version 2 for more details (a copy is included in the LICENSE file that
015 * accompanied this code).
016 *
017 * You should have received a copy of the GNU General Public License version
018 * 2 along with this work; if not, write to the Free Software Foundation,
019 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
020 *
021 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
022 * CA 95054 USA or visit www.sun.com if you need additional information or
023 * have any questions.
024 */
025
026 package java.security;
027
028 import java.util.HashMap;
029 import java.util.ArrayList;
030 import java.net.URL;
031
032 import sun.security.util.Debug;
033
034 /**
035 * This class extends ClassLoader with additional support for defining
036 * classes with an associated code source and permissions which are
037 * retrieved by the system policy by default.
038 *
039 * @version 1.93, 05/05/07
040 * @author Li Gong
041 * @author Roland Schemers
042 */
043 public class SecureClassLoader extends ClassLoader {
044 /*
045 * If initialization succeed this is set to true and security checks will
046 * succeed. Otherwise the object is not initialized and the object is
047 * useless.
048 */
049 private boolean initialized = false;
050
051 // HashMap that maps CodeSource to ProtectionDomain
052 private HashMap<CodeSource, ProtectionDomain> pdcache = new HashMap<CodeSource, ProtectionDomain>(
053 11);
054
055 private static final Debug debug = Debug.getInstance("scl");
056
057 /**
058 * Creates a new SecureClassLoader using the specified parent
059 * class loader for delegation.
060 *
061 * <p>If there is a security manager, this method first
062 * calls the security manager's <code>checkCreateClassLoader</code>
063 * method to ensure creation of a class loader is allowed.
064 * <p>
065 * @param parent the parent ClassLoader
066 * @exception SecurityException if a security manager exists and its
067 * <code>checkCreateClassLoader</code> method doesn't allow
068 * creation of a class loader.
069 * @see SecurityManager#checkCreateClassLoader
070 */
071 protected SecureClassLoader(ClassLoader parent) {
072 super (parent);
073 // this is to make the stack depth consistent with 1.1
074 SecurityManager security = System.getSecurityManager();
075 if (security != null) {
076 security.checkCreateClassLoader();
077 }
078 initialized = true;
079 }
080
081 /**
082 * Creates a new SecureClassLoader using the default parent class
083 * loader for delegation.
084 *
085 * <p>If there is a security manager, this method first
086 * calls the security manager's <code>checkCreateClassLoader</code>
087 * method to ensure creation of a class loader is allowed.
088 *
089 * @exception SecurityException if a security manager exists and its
090 * <code>checkCreateClassLoader</code> method doesn't allow
091 * creation of a class loader.
092 * @see SecurityManager#checkCreateClassLoader
093 */
094 protected SecureClassLoader() {
095 super ();
096 // this is to make the stack depth consistent with 1.1
097 SecurityManager security = System.getSecurityManager();
098 if (security != null) {
099 security.checkCreateClassLoader();
100 }
101 initialized = true;
102 }
103
104 /**
105 * Converts an array of bytes into an instance of class Class,
106 * with an optional CodeSource. Before the
107 * class can be used it must be resolved.
108 * <p>
109 * If a non-null CodeSource is supplied a ProtectionDomain is
110 * constructed and associated with the class being defined.
111 * <p>
112 * @param name the expected name of the class, or <code>null</code>
113 * if not known, using '.' and not '/' as the separator
114 * and without a trailing ".class" suffix.
115 * @param b the bytes that make up the class data. The bytes in
116 * positions <code>off</code> through <code>off+len-1</code>
117 * should have the format of a valid class file as defined
118 * by the
119 * <a href="http://java.sun.com/docs/books/vmspec/">Java
120 * Virtual Machine Specification</a>.
121 * @param off the start offset in <code>b</code> of the class data
122 * @param len the length of the class data
123 * @param cs the associated CodeSource, or <code>null</code> if none
124 * @return the <code>Class</code> object created from the data,
125 * and optional CodeSource.
126 * @exception ClassFormatError if the data did not contain a valid class
127 * @exception IndexOutOfBoundsException if either <code>off</code> or
128 * <code>len</code> is negative, or if
129 * <code>off+len</code> is greater than <code>b.length</code>.
130 *
131 * @exception SecurityException if an attempt is made to add this class
132 * to a package that contains classes that were signed by
133 * a different set of certificates than this class, or if
134 * the class name begins with "java.".
135 */
136 protected final Class<?> defineClass(String name, byte[] b,
137 int off, int len, CodeSource cs) {
138 if (cs == null)
139 return defineClass(name, b, off, len);
140 else
141 return defineClass(name, b, off, len,
142 getProtectionDomain(cs));
143 }
144
145 /**
146 * Converts a {@link java.nio.ByteBuffer <tt>ByteBuffer</tt>}
147 * into an instance of class <tt>Class</tt>, with an optional CodeSource.
148 * Before the class can be used it must be resolved.
149 * <p>
150 * If a non-null CodeSource is supplied a ProtectionDomain is
151 * constructed and associated with the class being defined.
152 * <p>
153 * @param name the expected name of the class, or <code>null</code>
154 * if not known, using '.' and not '/' as the separator
155 * and without a trailing ".class" suffix.
156 * @param b the bytes that make up the class data. The bytes from positions
157 * <tt>b.position()</tt> through <tt>b.position() + b.limit() -1</tt>
158 * should have the format of a valid class file as defined by the
159 * <a href="http://java.sun.com/docs/books/vmspec/">Java Virtual
160 * Machine Specification</a>.
161 * @param cs the associated CodeSource, or <code>null</code> if none
162 * @return the <code>Class</code> object created from the data,
163 * and optional CodeSource.
164 * @exception ClassFormatError if the data did not contain a valid class
165 * @exception SecurityException if an attempt is made to add this class
166 * to a package that contains classes that were signed by
167 * a different set of certificates than this class, or if
168 * the class name begins with "java.".
169 *
170 * @since 1.5
171 */
172 protected final Class<?> defineClass(String name,
173 java.nio.ByteBuffer b, CodeSource cs) {
174 if (cs == null)
175 return defineClass(name, b, (ProtectionDomain) null);
176 else
177 return defineClass(name, b, getProtectionDomain(cs));
178 }
179
180 /**
181 * Returns the permissions for the given CodeSource object.
182 * <p>
183 * This method is invoked by the defineClass method which takes
184 * a CodeSource as an argument when it is constructing the
185 * ProtectionDomain for the class being defined.
186 * <p>
187 * @param codesource the codesource.
188 *
189 * @return the permissions granted to the codesource.
190 *
191 */
192 protected PermissionCollection getPermissions(CodeSource codesource) {
193 check();
194 return new Permissions(); // ProtectionDomain defers the binding
195 }
196
197 /*
198 * Returned cached ProtectionDomain for the specified CodeSource.
199 */
200 private ProtectionDomain getProtectionDomain(CodeSource cs) {
201 if (cs == null)
202 return null;
203
204 ProtectionDomain pd = null;
205 synchronized (pdcache) {
206 pd = pdcache.get(cs);
207 if (pd == null) {
208 PermissionCollection perms = getPermissions(cs);
209 pd = new ProtectionDomain(cs, perms, this , null);
210 if (pd != null) {
211 pdcache.put(cs, pd);
212 if (debug != null) {
213 debug.println(" getPermissions " + pd);
214 debug.println("");
215 }
216 }
217 }
218 }
219 return pd;
220 }
221
222 /*
223 * Check to make sure the class loader has been initialized.
224 */
225 private void check() {
226 if (!initialized) {
227 throw new SecurityException(
228 "ClassLoader object not initialized");
229 }
230 }
231
232 }
|