1 /* 2 * Copyright (c) 1997, 2019, 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.security; 27 28 import java.util.Map; 29 import java.util.Objects; 30 import java.util.concurrent.ConcurrentHashMap; 31 import java.util.function.Function; 32 33 import sun.security.util.Debug; 34 35 /** 36 * This class extends ClassLoader with additional support for defining 37 * classes with an associated code source and permissions which are 38 * retrieved by the system policy by default. 39 * 40 * @author Li Gong 41 * @author Roland Schemers 42 * @since 1.2 43 */ 44 public class SecureClassLoader extends ClassLoader { 45 46 /* 47 * Map that maps the CodeSource to a ProtectionDomain. The key is a 48 * CodeSourceKey class that uses a String instead of a URL to avoid 49 * potential expensive name service lookups. This does mean that URLs that 50 * are equivalent after nameservice lookup will be placed in separate 51 * ProtectionDomains; however during policy enforcement these URLs will be 52 * canonicalized and resolved resulting in a consistent set of granted 53 * permissions. 54 */ 55 private final Map<CodeSourceKey, ProtectionDomain> pdcache 56 = new ConcurrentHashMap<>(11); 57 58 static { 59 ClassLoader.registerAsParallelCapable(); 60 } 61 62 /** 63 * Creates a new SecureClassLoader using the specified parent 64 * class loader for delegation. 65 * 66 * <p>If there is a security manager, this method first 67 * calls the security manager's {@code checkCreateClassLoader} 68 * method to ensure creation of a class loader is allowed. 69 * 70 * @param parent the parent ClassLoader 71 * @throws SecurityException if a security manager exists and its 72 * {@code checkCreateClassLoader} method doesn't allow 73 * creation of a class loader. 74 * @see SecurityManager#checkCreateClassLoader 75 */ 76 protected SecureClassLoader(ClassLoader parent) { 77 super(parent); 78 } 79 80 /** 81 * Creates a new SecureClassLoader using the default parent class 82 * loader for delegation. 83 * 84 * <p>If there is a security manager, this method first 85 * calls the security manager's {@code checkCreateClassLoader} 86 * method to ensure creation of a class loader is allowed. 87 * 88 * @throws SecurityException if a security manager exists and its 89 * {@code checkCreateClassLoader} method doesn't allow 90 * creation of a class loader. 91 * @see SecurityManager#checkCreateClassLoader 92 */ 93 protected SecureClassLoader() { 94 super(); 95 } 96 97 /** 98 * Creates a new {@code SecureClassLoader} of the specified name and 99 * using the specified parent class loader for delegation. 100 * 101 * @param name class loader name; or {@code null} if not named 102 * @param parent the parent class loader 103 * 104 * @throws IllegalArgumentException if the given name is empty. 105 * 106 * @throws SecurityException if a security manager exists and its 107 * {@link SecurityManager#checkCreateClassLoader()} method 108 * doesn't allow creation of a class loader. 109 * 110 * @since 9 111 * @spec JPMS 112 */ 113 protected SecureClassLoader(String name, ClassLoader parent) { 114 super(name, parent); 115 } 116 117 /** 118 * Converts an array of bytes into an instance of class Class, 119 * with an optional CodeSource. Before the 120 * class can be used it must be resolved. 121 * <p> 122 * If a non-null CodeSource is supplied a ProtectionDomain is 123 * constructed and associated with the class being defined. 124 * 125 * @param name the expected name of the class, or {@code null} 126 * if not known, using '.' and not '/' as the separator 127 * and without a trailing ".class" suffix. 128 * @param b the bytes that make up the class data. The bytes in 129 * positions {@code off} through {@code off+len-1} 130 * should have the format of a valid class file as defined by 131 * <cite>The Java Virtual Machine Specification</cite>. 132 * @param off the start offset in {@code b} of the class data 133 * @param len the length of the class data 134 * @param cs the associated CodeSource, or {@code null} if none 135 * @return the {@code Class} object created from the data, 136 * and optional CodeSource. 137 * @throws ClassFormatError if the data did not contain a valid class 138 * @throws IndexOutOfBoundsException if either {@code off} or 139 * {@code len} is negative, or if 140 * {@code off+len} is greater than {@code b.length}. 141 * 142 * @throws SecurityException if an attempt is made to add this class 143 * to a package that contains classes that were signed by 144 * a different set of certificates than this class, or if 145 * the class name begins with "java.". 146 */ 147 protected final Class<?> defineClass(String name, 148 byte[] b, int off, int len, 149 CodeSource cs) 150 { 151 return defineClass(name, b, off, len, getProtectionDomain(cs)); 152 } 153 154 /** 155 * Converts a {@link java.nio.ByteBuffer ByteBuffer} 156 * into an instance of class {@code Class}, with an optional CodeSource. 157 * Before the class can be used it must be resolved. 158 * <p> 159 * If a non-null CodeSource is supplied a ProtectionDomain is 160 * constructed and associated with the class being defined. 161 * 162 * @param name the expected name of the class, or {@code null} 163 * if not known, using '.' and not '/' as the separator 164 * and without a trailing ".class" suffix. 165 * @param b the bytes that make up the class data. The bytes from positions 166 * {@code b.position()} through {@code b.position() + b.limit() -1} 167 * should have the format of a valid class file as defined by 168 * <cite>The Java Virtual Machine Specification</cite>. 169 * @param cs the associated CodeSource, or {@code null} if none 170 * @return the {@code Class} object created from the data, 171 * and optional CodeSource. 172 * @throws ClassFormatError if the data did not contain a valid class 173 * @throws SecurityException if an attempt is made to add this class 174 * to a package that contains classes that were signed by 175 * a different set of certificates than this class, or if 176 * the class name begins with "java.". 177 * 178 * @since 1.5 179 */ 180 protected final Class<?> defineClass(String name, java.nio.ByteBuffer b, 181 CodeSource cs) 182 { 183 return defineClass(name, b, getProtectionDomain(cs)); 184 } 185 186 /** 187 * Returns the permissions for the given CodeSource object. 188 * <p> 189 * This method is invoked by the defineClass method which takes 190 * a CodeSource as an argument when it is constructing the 191 * ProtectionDomain for the class being defined. 192 * 193 * @param codesource the codesource. 194 * 195 * @return the permissions granted to the codesource. 196 * 197 */ 198 protected PermissionCollection getPermissions(CodeSource codesource) 199 { 200 return new Permissions(); // ProtectionDomain defers the binding 201 } 202 203 /* 204 * holder class for the static field "debug" to delay its initialization 205 */ 206 private static class DebugHolder { 207 private static final Debug debug = Debug.getInstance("scl"); 208 } 209 210 /* 211 * Returned cached ProtectionDomain for the specified CodeSource. 212 */ 213 private ProtectionDomain getProtectionDomain(CodeSource cs) { 214 if (cs == null) { 215 return null; 216 } 217 218 // Use a CodeSourceKey object key. It should behave in the 219 // same manner as the CodeSource when compared for equality except 220 // that no nameservice lookup is done on the hostname (String comparison 221 // only), and the fragment is not considered. 222 CodeSourceKey key = new CodeSourceKey(cs); 223 return pdcache.computeIfAbsent(key, new Function<>() { 224 @Override 225 public ProtectionDomain apply(CodeSourceKey key /* not used */) { 226 PermissionCollection perms 227 = SecureClassLoader.this.getPermissions(cs); 228 ProtectionDomain pd = new ProtectionDomain( 229 cs, perms, SecureClassLoader.this, null); 230 if (DebugHolder.debug != null) { 231 DebugHolder.debug.println(" getPermissions " + pd); 232 DebugHolder.debug.println(""); 233 } 234 return pd; 235 } 236 }); 237 } 238 239 private static class CodeSourceKey { 240 private final CodeSource cs; 241 242 CodeSourceKey(CodeSource cs) { 243 this.cs = cs; 244 } 245 246 @Override 247 public int hashCode() { 248 String locationNoFrag = cs.getLocationNoFragString(); 249 return locationNoFrag != null ? locationNoFrag.hashCode() : 0; 250 } 251 252 @Override 253 public boolean equals(Object obj) { 254 if (obj == this) { 255 return true; 256 } 257 258 if (!(obj instanceof CodeSourceKey)) { 259 return false; 260 } 261 262 CodeSourceKey csk = (CodeSourceKey) obj; 263 264 if (!Objects.equals(cs.getLocationNoFragString(), 265 csk.cs.getLocationNoFragString())) { 266 return false; 267 } 268 269 return cs.matchCerts(csk.cs, true); 270 } 271 } 272 }