Source for java.lang.SecurityManager

   1: /* SecurityManager.java -- security checks for privileged actions
   2:    Copyright (C) 1998, 1999, 2001, 2002, 2004, 2005 Free Software Foundation, Inc.
   3: 
   4: This file is part of GNU Classpath.
   5: 
   6: GNU Classpath is free software; you can redistribute it and/or modify
   7: it under the terms of the GNU General Public License as published by
   8: the Free Software Foundation; either version 2, or (at your option)
   9: any later version.
  10: 
  11: GNU Classpath is distributed in the hope that it will be useful, but
  12: WITHOUT ANY WARRANTY; without even the implied warranty of
  13: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14: General Public License for more details.
  15: 
  16: You should have received a copy of the GNU General Public License
  17: along with GNU Classpath; see the file COPYING.  If not, write to the
  18: Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19: 02110-1301 USA.
  20: 
  21: Linking this library statically or dynamically with other modules is
  22: making a combined work based on this library.  Thus, the terms and
  23: conditions of the GNU General Public License cover the whole
  24: combination.
  25: 
  26: As a special exception, the copyright holders of this library give you
  27: permission to link this library with independent modules to produce an
  28: executable, regardless of the license terms of these independent
  29: modules, and to copy and distribute the resulting executable under
  30: terms of your choice, provided that you also meet, for each linked
  31: independent module, the terms and conditions of the license of that
  32: module.  An independent module is a module which is not derived from
  33: or based on this library.  If you modify this library, you may extend
  34: this exception to your version of the library, but you are not
  35: obligated to do so.  If you do not wish to do so, delete this
  36: exception statement from your version. */
  37: 
  38: 
  39: package java.lang;
  40: 
  41: import gnu.classpath.VMStackWalker;
  42: 
  43: import java.awt.AWTPermission;
  44: import java.io.File;
  45: import java.io.FileDescriptor;
  46: import java.io.FileInputStream;
  47: import java.io.FileOutputStream;
  48: import java.io.FilePermission;
  49: import java.io.RandomAccessFile;
  50: import java.lang.reflect.Member;
  51: import java.net.InetAddress;
  52: import java.net.ServerSocket;
  53: import java.net.Socket;
  54: import java.net.SocketImplFactory;
  55: import java.net.SocketPermission;
  56: import java.net.URL;
  57: import java.net.URLStreamHandlerFactory;
  58: import java.security.AccessControlContext;
  59: import java.security.AccessControlException;
  60: import java.security.AccessController;
  61: import java.security.AllPermission;
  62: import java.security.BasicPermission;
  63: import java.security.Permission;
  64: import java.security.Policy;
  65: import java.security.PrivilegedAction;
  66: import java.security.ProtectionDomain;
  67: import java.security.Security;
  68: import java.security.SecurityPermission;
  69: import java.util.Properties;
  70: import java.util.PropertyPermission;
  71: import java.util.StringTokenizer;
  72: 
  73: /**
  74:  * SecurityManager is a class you can extend to create your own Java
  75:  * security policy.  By default, there is no SecurityManager installed in
  76:  * 1.1, which means that all things are permitted to all people. The security
  77:  * manager, if set, is consulted before doing anything with potentially
  78:  * dangerous results, and throws a <code>SecurityException</code> if the
  79:  * action is forbidden.
  80:  *
  81:  * <p>A typical check is as follows, just before the dangerous operation:<br>
  82:  * <pre>
  83:  * SecurityManager sm = System.getSecurityManager();
  84:  * if (sm != null)
  85:  *   sm.checkABC(<em>argument</em>, ...);
  86:  * </pre>
  87:  * Note that this is thread-safe, by caching the security manager in a local
  88:  * variable rather than risking a NullPointerException if the mangager is
  89:  * changed between the check for null and before the permission check.
  90:  *
  91:  * <p>The special method <code>checkPermission</code> is a catchall, and
  92:  * the default implementation calls
  93:  * <code>AccessController.checkPermission</code>. In fact, all the other
  94:  * methods default to calling checkPermission.
  95:  *
  96:  * <p>Sometimes, the security check needs to happen from a different context,
  97:  * such as when called from a worker thread. In such cases, use
  98:  * <code>getSecurityContext</code> to take a snapshot that can be passed
  99:  * to the worker thread:<br>
 100:  * <pre>
 101:  * Object context = null;
 102:  * SecurityManager sm = System.getSecurityManager();
 103:  * if (sm != null)
 104:  *   context = sm.getSecurityContext(); // defaults to an AccessControlContext
 105:  * // now, in worker thread
 106:  * if (sm != null)
 107:  *   sm.checkPermission(permission, context);
 108:  * </pre>
 109:  *
 110:  * <p>Permissions fall into these categories: File, Socket, Net, Security,
 111:  * Runtime, Property, AWT, Reflect, and Serializable. Each of these
 112:  * permissions have a property naming convention, that follows a hierarchical
 113:  * naming convention, to make it easy to grant or deny several permissions
 114:  * at once. Some permissions also take a list of permitted actions, such
 115:  * as "read" or "write", to fine-tune control even more. The permission
 116:  * <code>java.security.AllPermission</code> grants all permissions.
 117:  *
 118:  * <p>The default methods in this class deny all things to all people. You
 119:  * must explicitly grant permission for anything you want to be legal when
 120:  * subclassing this class.
 121:  *
 122:  * @author John Keiser
 123:  * @author Eric Blake (ebb9@email.byu.edu)
 124:  * @see ClassLoader
 125:  * @see SecurityException
 126:  * @see #checkTopLevelWindow(Object)
 127:  * @see System#getSecurityManager()
 128:  * @see System#setSecurityManager(SecurityManager)
 129:  * @see AccessController
 130:  * @see AccessControlContext
 131:  * @see AccessControlException
 132:  * @see Permission
 133:  * @see BasicPermission
 134:  * @see java.io.FilePermission
 135:  * @see java.net.SocketPermission
 136:  * @see java.util.PropertyPermission
 137:  * @see RuntimePermission
 138:  * @see java.awt.AWTPermission
 139:  * @see Policy
 140:  * @see SecurityPermission
 141:  * @see ProtectionDomain
 142:  * @since 1.0
 143:  * @status still missing 1.4 functionality
 144:  */
 145: public class SecurityManager
 146: {
 147:   /**
 148:    * The current security manager. This is located here instead of in
 149:    * System, to avoid security problems, as well as bootstrap issues.
 150:    * Make sure to access it in a thread-safe manner; it is package visible
 151:    * to avoid overhead in java.lang.
 152:    */
 153:   static volatile SecurityManager current;
 154: 
 155:   /**
 156:    * Tells whether or not the SecurityManager is currently performing a
 157:    * security check.
 158:    * @deprecated Use {@link #checkPermission(Permission)} instead.
 159:    */
 160:   protected boolean inCheck;
 161: 
 162:   /**
 163:    * Construct a new security manager. There may be a security check, of
 164:    * <code>RuntimePermission("createSecurityManager")</code>.
 165:    *
 166:    * @throws SecurityException if permission is denied
 167:    */
 168:   public SecurityManager()
 169:   {
 170:     /* "When there is security manager installed, the security manager
 171:        need to check the package access. However, if the security
 172:        manager itself uses any unloaded class, it will trigger the
 173:        classloading, which causes infinite loop. There is no easy
 174:        legal solution. The workaround will be that security manager
 175:        can not depend on any unloaded class. In the constructor of
 176:        security manager, it must transitively load all classes it
 177:        refers to."  Sun bug #4242924.  */
 178: 
 179:     // Load and initialize java.security.Security
 180:     java.security.Security.getProvider((String)null);
 181: 
 182:     SecurityManager sm = System.getSecurityManager();
 183:     if (sm != null)
 184:       sm.checkPermission(new RuntimePermission("createSecurityManager"));
 185:   }
 186: 
 187:   /**
 188:    * Tells whether or not the SecurityManager is currently performing a
 189:    * security check.
 190:    *
 191:    * @return true if the SecurityManager is in a security check
 192:    * @see #inCheck
 193:    * @deprecated use {@link #checkPermission(Permission)} instead
 194:    */
 195:   public boolean getInCheck()
 196:   {
 197:     return inCheck;
 198:   }
 199: 
 200:   /**
 201:    * Get a list of all the classes currently executing methods on the Java
 202:    * stack.  getClassContext()[0] is the currently executing method (ie. the
 203:    * class that CALLED getClassContext, not SecurityManager).
 204:    *
 205:    * @return an array of classes on the Java execution stack
 206:    */
 207:   protected Class[] getClassContext()
 208:   {
 209:     Class[] stack1 = VMStackWalker.getClassContext();
 210:     Class[] stack2 = new Class[stack1.length - 1];
 211:     System.arraycopy(stack1, 1, stack2, 0, stack1.length - 1);
 212:     return stack2;
 213:   }
 214: 
 215:   /**
 216:    * Find the ClassLoader of the first non-system class on the execution
 217:    * stack. A non-system class is one whose ClassLoader is not equal to
 218:    * {@link ClassLoader#getSystemClassLoader()} or its ancestors. This
 219:    * will return null in three cases:
 220:    *
 221:    * <ul>
 222:    * <li>All methods on the stack are from system classes</li>
 223:    * <li>All methods on the stack up to the first "privileged" caller, as
 224:    *  created by {@link AccessController#doPrivileged(PrivilegedAction)},
 225:    *  are from system classes</li>
 226:    * <li>A check of <code>java.security.AllPermission</code> succeeds.</li>
 227:    * </ul>
 228:    * 
 229:    * @return the most recent non-system ClassLoader on the execution stack
 230:    * @deprecated use {@link #checkPermission(Permission)} instead
 231:    */
 232:   protected ClassLoader currentClassLoader()
 233:   {
 234:     Class cl = currentLoadedClass();
 235:     return cl != null ? cl.getClassLoader() : null;
 236:   }
 237: 
 238:   /**
 239:    * Find the first non-system class on the execution stack. A non-system
 240:    * class is one whose ClassLoader is not equal to
 241:    * {@link ClassLoader#getSystemClassLoader()} or its ancestors. This
 242:    * will return null in three cases:
 243:    *
 244:    * <ul>
 245:    * <li>All methods on the stack are from system classes</li>
 246:    * <li>All methods on the stack up to the first "privileged" caller, as
 247:    *  created by {@link AccessController#doPrivileged(PrivilegedAction)},
 248:    *  are from system classes</li>
 249:    * <li>A check of <code>java.security.AllPermission</code> succeeds.</li>
 250:    * </ul>
 251:    * 
 252:    * @return the most recent non-system Class on the execution stack
 253:    * @deprecated use {@link #checkPermission(Permission)} instead
 254:    */
 255:   protected Class<?> currentLoadedClass()
 256:   {
 257:     int i = classLoaderDepth();
 258:     return i >= 0 ? getClassContext()[i] : null;
 259:   }
 260: 
 261:   /**
 262:    * Get the depth of a particular class on the execution stack.
 263:    *
 264:    * @param className the fully-qualified name to search for
 265:    * @return the index of the class on the stack, or -1
 266:    * @deprecated use {@link #checkPermission(Permission)} instead
 267:    */
 268:   protected int classDepth(String className)
 269:   {
 270:     Class[] c = getClassContext();
 271:     for (int i = 0; i < c.length; i++)
 272:       if (className.equals(c[i].getName()))
 273:         return i;
 274:     return -1;
 275:   }
 276: 
 277:   /**
 278:    * Get the depth on the execution stack of the most recent non-system class.
 279:    * A non-system class is one whose ClassLoader is not equal to
 280:    * {@link ClassLoader#getSystemClassLoader()} or its ancestors. This
 281:    * will return -1 in three cases:
 282:    *
 283:    * <ul>
 284:    * <li>All methods on the stack are from system classes</li>
 285:    * <li>All methods on the stack up to the first "privileged" caller, as
 286:    *  created by {@link AccessController#doPrivileged(PrivilegedAction)},
 287:    *  are from system classes</li>
 288:    * <li>A check of <code>java.security.AllPermission</code> succeeds.</li>
 289:    * </ul>
 290:    * 
 291:    * @return the index of the most recent non-system Class on the stack
 292:    * @deprecated use {@link #checkPermission(Permission)} instead
 293:    */
 294:   protected int classLoaderDepth()
 295:   {
 296:     try
 297:       {
 298:         checkPermission(new AllPermission());
 299:       }
 300:     catch (SecurityException e)
 301:       {
 302:         Class[] c = getClassContext();
 303:         for (int i = 0; i < c.length; i++)
 304:           if (c[i].getClassLoader() != null)
 305:             // XXX Check if c[i] is AccessController, or a system class.
 306:             return i;
 307:       }
 308:     return -1;
 309:   }
 310: 
 311:   /**
 312:    * Tell whether the specified class is on the execution stack.
 313:    *
 314:    * @param className the fully-qualified name of the class to find
 315:    * @return whether the specified class is on the execution stack
 316:    * @deprecated use {@link #checkPermission(Permission)} instead
 317:    */
 318:   protected boolean inClass(String className)
 319:   {
 320:     return classDepth(className) != -1;
 321:   }
 322: 
 323:   /**
 324:    * Tell whether there is a class loaded with an explicit ClassLoader on
 325:    * the stack.
 326:    *
 327:    * @return whether a class with an explicit ClassLoader is on the stack
 328:    * @deprecated use {@link #checkPermission(Permission)} instead
 329:    */
 330:   protected boolean inClassLoader()
 331:   {
 332:     return classLoaderDepth() != -1;
 333:   }
 334: 
 335:   /**
 336:    * Get an implementation-dependent Object that contains enough information
 337:    * about the current environment to be able to perform standard security
 338:    * checks later.  This is used by trusted methods that need to verify that
 339:    * their callers have sufficient access to perform certain operations.
 340:    *
 341:    * <p>Currently the only methods that use this are checkRead() and
 342:    * checkConnect(). The default implementation returns an
 343:    * <code>AccessControlContext</code>.
 344:    *
 345:    * @return a security context
 346:    * @see #checkConnect(String, int, Object)
 347:    * @see #checkRead(String, Object)
 348:    * @see AccessControlContext
 349:    * @see AccessController#getContext()
 350:    */
 351:   public Object getSecurityContext()
 352:   {
 353:     return AccessController.getContext();
 354:   }
 355: 
 356:   /**
 357:    * Check if the current thread is allowed to perform an operation that
 358:    * requires the specified <code>Permission</code>. This defaults to
 359:    * <code>AccessController.checkPermission</code>.
 360:    *
 361:    * @param perm the <code>Permission</code> required
 362:    * @throws SecurityException if permission is denied
 363:    * @throws NullPointerException if perm is null
 364:    * @since 1.2
 365:    */
 366:   public void checkPermission(Permission perm)
 367:   {
 368:     AccessController.checkPermission(perm);
 369:   }
 370: 
 371:   /**
 372:    * Check if the current thread is allowed to perform an operation that
 373:    * requires the specified <code>Permission</code>. This is done in a
 374:    * context previously returned by <code>getSecurityContext()</code>. The
 375:    * default implementation expects context to be an AccessControlContext,
 376:    * and it calls <code>AccessControlContext.checkPermission(perm)</code>.
 377:    *
 378:    * @param perm the <code>Permission</code> required
 379:    * @param context a security context
 380:    * @throws SecurityException if permission is denied, or if context is
 381:    *         not an AccessControlContext
 382:    * @throws NullPointerException if perm is null
 383:    * @see #getSecurityContext()
 384:    * @see AccessControlContext#checkPermission(Permission)
 385:    * @since 1.2
 386:    */
 387:   public void checkPermission(Permission perm, Object context)
 388:   {
 389:     if (! (context instanceof AccessControlContext))
 390:       throw new SecurityException("Missing context");
 391:     ((AccessControlContext) context).checkPermission(perm);
 392:   }
 393: 
 394:   /**
 395:    * Check if the current thread is allowed to create a ClassLoader. This
 396:    * method is called from ClassLoader.ClassLoader(), and checks
 397:    * <code>RuntimePermission("createClassLoader")</code>. If you override
 398:    * this, you should call <code>super.checkCreateClassLoader()</code> rather
 399:    * than throwing an exception.
 400:    *
 401:    * @throws SecurityException if permission is denied
 402:    * @see ClassLoader#ClassLoader()
 403:    */
 404:   public void checkCreateClassLoader()
 405:   {
 406:     checkPermission(new RuntimePermission("createClassLoader"));
 407:   }
 408: 
 409:   /**
 410:    * Check if the current thread is allowed to modify another Thread. This is
 411:    * called by Thread.stop(), suspend(), resume(), interrupt(), destroy(),
 412:    * setPriority(), setName(), and setDaemon(). The default implementation
 413:    * checks <code>RuntimePermission("modifyThread")</code> on system threads
 414:    * (ie. threads in ThreadGroup with a null parent), and returns silently on
 415:    * other threads.
 416:    *
 417:    * <p>If you override this, you must do two things. First, call
 418:    * <code>super.checkAccess(t)</code>, to make sure you are not relaxing
 419:    * requirements. Second, if the calling thread has
 420:    * <code>RuntimePermission("modifyThread")</code>, return silently, so that
 421:    * core classes (the Classpath library!) can modify any thread.
 422:    *
 423:    * @param thread the other Thread to check
 424:    * @throws SecurityException if permission is denied
 425:    * @throws NullPointerException if thread is null
 426:    * @see Thread#stop()
 427:    * @see Thread#suspend()
 428:    * @see Thread#resume()
 429:    * @see Thread#setPriority(int)
 430:    * @see Thread#setName(String)
 431:    * @see Thread#setDaemon(boolean)
 432:    */
 433:   public void checkAccess(Thread thread)
 434:   {
 435:     if (thread.getThreadGroup() != null 
 436:     && thread.getThreadGroup().parent == null)
 437:       checkPermission(new RuntimePermission("modifyThread"));
 438:   }
 439: 
 440:   /**
 441:    * Check if the current thread is allowed to modify a ThreadGroup. This is
 442:    * called by Thread.Thread() (to add a thread to the ThreadGroup),
 443:    * ThreadGroup.ThreadGroup() (to add this ThreadGroup to a parent),
 444:    * ThreadGroup.stop(), suspend(), resume(), interrupt(), destroy(),
 445:    * setDaemon(), and setMaxPriority(). The default implementation
 446:    * checks <code>RuntimePermission("modifyThread")</code> on the system group
 447:    * (ie. the one with a null parent), and returns silently on other groups.
 448:    *
 449:    * <p>If you override this, you must do two things. First, call
 450:    * <code>super.checkAccess(t)</code>, to make sure you are not relaxing
 451:    * requirements. Second, if the calling thread has
 452:    * <code>RuntimePermission("modifyThreadGroup")</code>, return silently,
 453:    * so that core classes (the Classpath library!) can modify any thread.
 454:    *
 455:    * @param g the ThreadGroup to check
 456:    * @throws SecurityException if permission is denied
 457:    * @throws NullPointerException if g is null
 458:    * @see Thread#Thread()
 459:    * @see ThreadGroup#ThreadGroup(String)
 460:    * @see ThreadGroup#stop()
 461:    * @see ThreadGroup#suspend()
 462:    * @see ThreadGroup#resume()
 463:    * @see ThreadGroup#interrupt()
 464:    * @see ThreadGroup#setDaemon(boolean)
 465:    * @see ThreadGroup#setMaxPriority(int)
 466:    */
 467:   public void checkAccess(ThreadGroup g)
 468:   {
 469:     if (g.parent == null)
 470:       checkPermission(new RuntimePermission("modifyThreadGroup"));
 471:   }
 472: 
 473:   /**
 474:    * Check if the current thread is allowed to exit the JVM with the given
 475:    * status. This method is called from Runtime.exit() and Runtime.halt().
 476:    * The default implementation checks
 477:    * <code>RuntimePermission("exitVM")</code>. If you override this, call
 478:    * <code>super.checkExit</code> rather than throwing an exception.
 479:    *
 480:    * @param status the status to exit with
 481:    * @throws SecurityException if permission is denied
 482:    * @see Runtime#exit(int)
 483:    * @see Runtime#halt(int)
 484:    */
 485:   public void checkExit(int status)
 486:   {
 487:     checkPermission(new RuntimePermission("exitVM"));
 488:   }
 489: 
 490:   /**
 491:    * Check if the current thread is allowed to execute the given program. This
 492:    * method is called from Runtime.exec(). If the name is an absolute path,
 493:    * the default implementation checks
 494:    * <code>FilePermission(program, "execute")</code>, otherwise it checks
 495:    * <code>FilePermission("&lt;&lt;ALL FILES&gt;&gt;", "execute")</code>. If
 496:    * you override this, call <code>super.checkExec</code> rather than
 497:    * throwing an exception.
 498:    *
 499:    * @param program the name of the program to exec
 500:    * @throws SecurityException if permission is denied
 501:    * @throws NullPointerException if program is null
 502:    * @see Runtime#exec(String[], String[], File)
 503:    */
 504:   public void checkExec(String program)
 505:   {
 506:     if (! program.equals(new File(program).getAbsolutePath()))
 507:       program = "<<ALL FILES>>";
 508:     checkPermission(new FilePermission(program, "execute"));
 509:   }
 510: 
 511:   /**
 512:    * Check if the current thread is allowed to link in the given native
 513:    * library. This method is called from Runtime.load() (and hence, by
 514:    * loadLibrary() as well). The default implementation checks
 515:    * <code>RuntimePermission("loadLibrary." + filename)</code>. If you
 516:    * override this, call <code>super.checkLink</code> rather than throwing
 517:    * an exception.
 518:    *
 519:    * @param filename the full name of the library to load
 520:    * @throws SecurityException if permission is denied
 521:    * @throws NullPointerException if filename is null
 522:    * @see Runtime#load(String)
 523:    */
 524:   public void checkLink(String filename)
 525:   {
 526:     // Use the toString() hack to do the null check.
 527:     checkPermission(new RuntimePermission("loadLibrary."
 528:                                           + filename.toString()));
 529:   }
 530: 
 531:   /**
 532:    * Check if the current thread is allowed to read the given file using the
 533:    * FileDescriptor. This method is called from
 534:    * FileInputStream.FileInputStream(). The default implementation checks
 535:    * <code>RuntimePermission("readFileDescriptor")</code>. If you override
 536:    * this, call <code>super.checkRead</code> rather than throwing an
 537:    * exception.
 538:    *
 539:    * @param desc the FileDescriptor representing the file to access
 540:    * @throws SecurityException if permission is denied
 541:    * @throws NullPointerException if desc is null
 542:    * @see FileInputStream#FileInputStream(FileDescriptor)
 543:    */
 544:   public void checkRead(FileDescriptor desc)
 545:   {
 546:     if (desc == null)
 547:       throw new NullPointerException();
 548:     checkPermission(new RuntimePermission("readFileDescriptor"));
 549:   }
 550: 
 551:   /**
 552:    * Check if the current thread is allowed to read the given file. This
 553:    * method is called from FileInputStream.FileInputStream(),
 554:    * RandomAccessFile.RandomAccessFile(), File.exists(), canRead(), isFile(),
 555:    * isDirectory(), lastModified(), length() and list(). The default
 556:    * implementation checks <code>FilePermission(filename, "read")</code>. If
 557:    * you override this, call <code>super.checkRead</code> rather than
 558:    * throwing an exception.
 559:    *
 560:    * @param filename the full name of the file to access
 561:    * @throws SecurityException if permission is denied
 562:    * @throws NullPointerException if filename is null
 563:    * @see File
 564:    * @see FileInputStream#FileInputStream(String)
 565:    * @see RandomAccessFile#RandomAccessFile(String, String)
 566:    */
 567:   public void checkRead(String filename)
 568:   {
 569:     checkPermission(new FilePermission(filename, "read"));
 570:   }
 571: 
 572:   /**
 573:    * Check if the current thread is allowed to read the given file. using the
 574:    * given security context. The context must be a result of a previous call
 575:    * to <code>getSecurityContext()</code>. The default implementation checks
 576:    * <code>AccessControlContext.checkPermission(new FilePermission(filename,
 577:    * "read"))</code>. If you override this, call <code>super.checkRead</code>
 578:    * rather than throwing an exception.
 579:    *
 580:    * @param filename the full name of the file to access
 581:    * @param context the context to determine access for
 582:    * @throws SecurityException if permission is denied, or if context is
 583:    *         not an AccessControlContext
 584:    * @throws NullPointerException if filename is null
 585:    * @see #getSecurityContext()
 586:    * @see AccessControlContext#checkPermission(Permission)
 587:    */
 588:   public void checkRead(String filename, Object context)
 589:   {
 590:     if (! (context instanceof AccessControlContext))
 591:       throw new SecurityException("Missing context");
 592:     AccessControlContext ac = (AccessControlContext) context;
 593:     ac.checkPermission(new FilePermission(filename, "read"));
 594:   }
 595: 
 596:   /**
 597:    * Check if the current thread is allowed to write the given file using the
 598:    * FileDescriptor. This method is called from
 599:    * FileOutputStream.FileOutputStream(). The default implementation checks
 600:    * <code>RuntimePermission("writeFileDescriptor")</code>. If you override
 601:    * this, call <code>super.checkWrite</code> rather than throwing an
 602:    * exception.
 603:    *
 604:    * @param desc the FileDescriptor representing the file to access
 605:    * @throws SecurityException if permission is denied
 606:    * @throws NullPointerException if desc is null
 607:    * @see FileOutputStream#FileOutputStream(FileDescriptor)
 608:    */
 609:   public void checkWrite(FileDescriptor desc)
 610:   {
 611:     if (desc == null)
 612:       throw new NullPointerException();
 613:     checkPermission(new RuntimePermission("writeFileDescriptor"));
 614:   }
 615: 
 616:   /**
 617:    * Check if the current thread is allowed to write the given file. This
 618:    * method is called from FileOutputStream.FileOutputStream(),
 619:    * RandomAccessFile.RandomAccessFile(), File.canWrite(), mkdir(), and
 620:    * renameTo(). The default implementation checks
 621:    * <code>FilePermission(filename, "write")</code>. If you override this,
 622:    * call <code>super.checkWrite</code> rather than throwing an exception.
 623:    *
 624:    * @param filename the full name of the file to access
 625:    * @throws SecurityException if permission is denied
 626:    * @throws NullPointerException if filename is null
 627:    * @see File
 628:    * @see File#canWrite()
 629:    * @see File#mkdir()
 630:    * @see File#renameTo(File)
 631:    * @see FileOutputStream#FileOutputStream(String)
 632:    * @see RandomAccessFile#RandomAccessFile(String, String)
 633:    */
 634:   public void checkWrite(String filename)
 635:   {
 636:     checkPermission(new FilePermission(filename, "write"));
 637:   }
 638: 
 639:   /**
 640:    * Check if the current thread is allowed to delete the given file. This
 641:    * method is called from File.delete(). The default implementation checks
 642:    * <code>FilePermission(filename, "delete")</code>. If you override this,
 643:    * call <code>super.checkDelete</code> rather than throwing an exception.
 644:    *
 645:    * @param filename the full name of the file to delete
 646:    * @throws SecurityException if permission is denied
 647:    * @throws NullPointerException if filename is null
 648:    * @see File#delete()
 649:    */
 650:   public void checkDelete(String filename)
 651:   {
 652:     checkPermission(new FilePermission(filename, "delete"));
 653:   }
 654: 
 655:   /**
 656:    * Check if the current thread is allowed to connect to a given host on a
 657:    * given port. This method is called from Socket.Socket(). A port number
 658:    * of -1 indicates the caller is attempting to determine an IP address, so
 659:    * the default implementation checks
 660:    * <code>SocketPermission(host, "resolve")</code>. Otherwise, the default
 661:    * implementation checks
 662:    * <code>SocketPermission(host + ":" + port, "connect")</code>. If you
 663:    * override this, call <code>super.checkConnect</code> rather than throwing
 664:    * an exception.
 665:    *
 666:    * @param host the host to connect to
 667:    * @param port the port to connect on
 668:    * @throws SecurityException if permission is denied
 669:    * @throws NullPointerException if host is null
 670:    * @see Socket#Socket()
 671:    */
 672:   public void checkConnect(String host, int port)
 673:   {
 674:     if (port == -1)
 675:       checkPermission(new SocketPermission(host, "resolve"));
 676:     else
 677:       // Use the toString() hack to do the null check.
 678:       checkPermission(new SocketPermission(host.toString() + ":" + port,
 679:                                            "connect"));
 680:   }
 681: 
 682:   /**
 683:    * Check if the current thread is allowed to connect to a given host on a
 684:    * given port, using the given security context. The context must be a
 685:    * result of a previous call to <code>getSecurityContext</code>. A port
 686:    * number of -1 indicates the caller is attempting to determine an IP
 687:    * address, so the default implementation checks
 688:    * <code>AccessControlContext.checkPermission(new SocketPermission(host,
 689:    * "resolve"))</code>. Otherwise, the default implementation checks
 690:    * <code>AccessControlContext.checkPermission(new SocketPermission(host
 691:    * + ":" + port, "connect"))</code>. If you override this, call
 692:    * <code>super.checkConnect</code> rather than throwing an exception.
 693:    *
 694:    * @param host the host to connect to
 695:    * @param port the port to connect on
 696:    * @param context the context to determine access for
 697:    *
 698:    * @throws SecurityException if permission is denied, or if context is
 699:    *         not an AccessControlContext
 700:    * @throws NullPointerException if host is null
 701:    *
 702:    * @see #getSecurityContext()
 703:    * @see AccessControlContext#checkPermission(Permission)
 704:    */
 705:   public void checkConnect(String host, int port, Object context)
 706:   {
 707:     if (! (context instanceof AccessControlContext))
 708:       throw new SecurityException("Missing context");
 709:     AccessControlContext ac = (AccessControlContext) context;
 710:     if (port == -1)
 711:       ac.checkPermission(new SocketPermission(host, "resolve"));
 712:     else
 713:       // Use the toString() hack to do the null check.
 714:       ac.checkPermission(new SocketPermission(host.toString() + ":" + port,
 715:                                               "connect"));
 716:   }
 717: 
 718:   /**
 719:    * Check if the current thread is allowed to listen to a specific port for
 720:    * data. This method is called by ServerSocket.ServerSocket(). The default
 721:    * implementation checks
 722:    * <code>SocketPermission("localhost:" + (port == 0 ? "1024-" : "" + port),
 723:    * "listen")</code>. If you override this, call
 724:    * <code>super.checkListen</code> rather than throwing an exception.
 725:    *
 726:    * @param port the port to listen on
 727:    * @throws SecurityException if permission is denied
 728:    * @see ServerSocket#ServerSocket(int)
 729:    */
 730:   public void checkListen(int port)
 731:   {
 732:     checkPermission(new SocketPermission("localhost:"
 733:                                          + (port == 0 ? "1024-" : "" +port),
 734:                                          "listen"));
 735:   }
 736: 
 737:   /**
 738:    * Check if the current thread is allowed to accept a connection from a
 739:    * particular host on a particular port. This method is called by
 740:    * ServerSocket.implAccept(). The default implementation checks
 741:    * <code>SocketPermission(host + ":" + port, "accept")</code>. If you
 742:    * override this, call <code>super.checkAccept</code> rather than throwing
 743:    * an exception.
 744:    *
 745:    * @param host the host which wishes to connect
 746:    * @param port the port the connection will be on
 747:    * @throws SecurityException if permission is denied
 748:    * @throws NullPointerException if host is null
 749:    * @see ServerSocket#accept()
 750:    */
 751:   public void checkAccept(String host, int port)
 752:   {
 753:     // Use the toString() hack to do the null check.
 754:     checkPermission(new SocketPermission(host.toString() + ":" + port,
 755:                                          "accept"));
 756:   }
 757: 
 758:   /**
 759:    * Check if the current thread is allowed to read and write multicast to
 760:    * a particular address. The default implementation checks
 761:    * <code>SocketPermission(addr.getHostAddress(), "accept,connect")</code>.
 762:    * If you override this, call <code>super.checkMulticast</code> rather than
 763:    * throwing an exception.
 764:    *
 765:    * @param addr the address to multicast to
 766:    * @throws SecurityException if permission is denied
 767:    * @throws NullPointerException if host is null
 768:    * @since 1.1
 769:    */
 770:   public void checkMulticast(InetAddress addr)
 771:   {
 772:     checkPermission(new SocketPermission(addr.getHostAddress(),
 773:                                          "accept,connect"));
 774:   }
 775: 
 776:   /**
 777:    *Check if the current thread is allowed to read and write multicast to
 778:    * a particular address with a particular ttl (time-to-live) value. The
 779:    * default implementation ignores ttl, and checks
 780:    * <code>SocketPermission(addr.getHostAddress(), "accept,connect")</code>.
 781:    * If you override this, call <code>super.checkMulticast</code> rather than
 782:    * throwing an exception.
 783:    *
 784:    * @param addr the address to multicast to
 785:    * @param ttl value in use for multicast send
 786:    * @throws SecurityException if permission is denied
 787:    * @throws NullPointerException if host is null
 788:    * @since 1.1
 789:    * @deprecated use {@link #checkPermission(Permission)} instead
 790:    */
 791:   public void checkMulticast(InetAddress addr, byte ttl)
 792:   {
 793:     checkPermission(new SocketPermission(addr.getHostAddress(),
 794:                                          "accept,connect"));
 795:   }
 796: 
 797:   /**
 798:    * Check if the current thread is allowed to read or write all the system
 799:    * properties at once. This method is called by System.getProperties()
 800:    * and setProperties(). The default implementation checks
 801:    * <code>PropertyPermission("*", "read,write")</code>. If you override
 802:    * this, call <code>super.checkPropertiesAccess</code> rather than
 803:    * throwing an exception.
 804:    *
 805:    * @throws SecurityException if permission is denied
 806:    * @see System#getProperties()
 807:    * @see System#setProperties(Properties)
 808:    */
 809:   public void checkPropertiesAccess()
 810:   {
 811:     checkPermission(new PropertyPermission("*", "read,write"));
 812:   }
 813: 
 814:   /**
 815:    * Check if the current thread is allowed to read a particular system
 816:    * property (writes are checked directly via checkPermission). This method
 817:    * is called by System.getProperty() and setProperty(). The default
 818:    * implementation checks <code>PropertyPermission(key, "read")</code>. If
 819:    * you override this, call <code>super.checkPropertyAccess</code> rather
 820:    * than throwing an exception.
 821:    *
 822:    * @param key the key of the property to check
 823:    *
 824:    * @throws SecurityException if permission is denied
 825:    * @throws NullPointerException if key is null
 826:    * @throws IllegalArgumentException if key is ""
 827:    *
 828:    * @see System#getProperty(String)
 829:    */
 830:   public void checkPropertyAccess(String key)
 831:   {
 832:     checkPermission(new PropertyPermission(key, "read"));
 833:   }
 834: 
 835:   /**
 836:    * Check if the current thread is allowed to create a top-level window. If
 837:    * it is not, the operation should still go through, but some sort of
 838:    * nonremovable warning should be placed on the window to show that it
 839:    * is untrusted. This method is called by Window.Window(). The default
 840:    * implementation checks
 841:    * <code>AWTPermission("showWindowWithoutWarningBanner")</code>, and returns
 842:    * true if no exception was thrown. If you override this, use
 843:    * <code>return super.checkTopLevelWindow</code> rather than returning
 844:    * false.
 845:    *
 846:    * @param window the window to create
 847:    * @return true if there is permission to show the window without warning
 848:    * @throws NullPointerException if window is null
 849:    * @see java.awt.Window#Window(java.awt.Frame)
 850:    */
 851:   public boolean checkTopLevelWindow(Object window)
 852:   {
 853:     if (window == null)
 854:       throw new NullPointerException();
 855:     try
 856:       {
 857:         checkPermission(new AWTPermission("showWindowWithoutWarningBanner"));
 858:         return true;
 859:       }
 860:     catch (SecurityException e)
 861:       {
 862:         return false;
 863:       }
 864:   }
 865: 
 866:   /**
 867:    * Check if the current thread is allowed to create a print job. This
 868:    * method is called by Toolkit.getPrintJob(). The default implementation
 869:    * checks <code>RuntimePermission("queuePrintJob")</code>. If you override
 870:    * this, call <code>super.checkPrintJobAccess</code> rather than throwing
 871:    * an exception.
 872:    *
 873:    * @throws SecurityException if permission is denied
 874:    * @see java.awt.Toolkit#getPrintJob(java.awt.Frame, String, Properties)
 875:    * @since 1.1
 876:    */
 877:   public void checkPrintJobAccess()
 878:   {
 879:     checkPermission(new RuntimePermission("queuePrintJob"));
 880:   }
 881: 
 882:   /**
 883:    * Check if the current thread is allowed to use the system clipboard. This
 884:    * method is called by Toolkit.getSystemClipboard(). The default
 885:    * implementation checks <code>AWTPermission("accessClipboard")</code>. If
 886:    * you override this, call <code>super.checkSystemClipboardAccess</code>
 887:    * rather than throwing an exception.
 888:    *
 889:    * @throws SecurityException if permission is denied
 890:    * @see java.awt.Toolkit#getSystemClipboard()
 891:    * @since 1.1
 892:    */
 893:   public void checkSystemClipboardAccess()
 894:   {
 895:     checkPermission(new AWTPermission("accessClipboard"));
 896:   }
 897: 
 898:   /**
 899:    * Check if the current thread is allowed to use the AWT event queue. This
 900:    * method is called by Toolkit.getSystemEventQueue(). The default
 901:    * implementation checks <code>AWTPermission("accessEventQueue")</code>.
 902:    * you override this, call <code>super.checkAwtEventQueueAccess</code>
 903:    * rather than throwing an exception.
 904:    *
 905:    * @throws SecurityException if permission is denied
 906:    * @see java.awt.Toolkit#getSystemEventQueue()
 907:    * @since 1.1
 908:    */
 909:   public void checkAwtEventQueueAccess()
 910:   {
 911:     checkPermission(new AWTPermission("accessEventQueue"));
 912:   }
 913: 
 914:   /**
 915:    * Check if the current thread is allowed to access the specified package
 916:    * at all. This method is called by ClassLoader.loadClass() in user-created
 917:    * ClassLoaders. The default implementation gets a list of all restricted
 918:    * packages, via <code>Security.getProperty("package.access")</code>. Then,
 919:    * if packageName starts with or equals any restricted package, it checks
 920:    * <code>RuntimePermission("accessClassInPackage." + packageName)</code>.
 921:    * If you override this, you should call
 922:    * <code>super.checkPackageAccess</code> before doing anything else.
 923:    *
 924:    * @param packageName the package name to check access to
 925:    * @throws SecurityException if permission is denied
 926:    * @throws NullPointerException if packageName is null
 927:    * @see ClassLoader#loadClass(String, boolean)
 928:    * @see Security#getProperty(String)
 929:    */
 930:   public void checkPackageAccess(String packageName)
 931:   {
 932:     checkPackageList(packageName, "package.access", "accessClassInPackage.");
 933:   }
 934: 
 935:   /**
 936:    * Check if the current thread is allowed to define a class into the
 937:    * specified package. This method is called by ClassLoader.loadClass() in
 938:    * user-created ClassLoaders. The default implementation gets a list of all
 939:    * restricted packages, via
 940:    * <code>Security.getProperty("package.definition")</code>. Then, if
 941:    * packageName starts with or equals any restricted package, it checks
 942:    * <code>RuntimePermission("defineClassInPackage." + packageName)</code>.
 943:    * If you override this, you should call
 944:    * <code>super.checkPackageDefinition</code> before doing anything else.
 945:    *
 946:    * @param packageName the package name to check access to
 947:    * @throws SecurityException if permission is denied
 948:    * @throws NullPointerException if packageName is null
 949:    * @see ClassLoader#loadClass(String, boolean)
 950:    * @see Security#getProperty(String)
 951:    */
 952:   public void checkPackageDefinition(String packageName)
 953:   {
 954:     checkPackageList(packageName, "package.definition", "defineClassInPackage.");
 955:   }
 956: 
 957:   /**
 958:    * Check if the current thread is allowed to set the current socket factory.
 959:    * This method is called by Socket.setSocketImplFactory(),
 960:    * ServerSocket.setSocketFactory(), and URL.setURLStreamHandlerFactory().
 961:    * The default implementation checks
 962:    * <code>RuntimePermission("setFactory")</code>. If you override this, call
 963:    * <code>super.checkSetFactory</code> rather than throwing an exception.
 964:    *
 965:    * @throws SecurityException if permission is denied
 966:    * @see Socket#setSocketImplFactory(SocketImplFactory)
 967:    * @see ServerSocket#setSocketFactory(SocketImplFactory)
 968:    * @see URL#setURLStreamHandlerFactory(URLStreamHandlerFactory)
 969:    */
 970:   public void checkSetFactory()
 971:   {
 972:     checkPermission(new RuntimePermission("setFactory"));
 973:   }
 974: 
 975:   /**
 976:    * Check if the current thread is allowed to get certain types of Methods,
 977:    * Fields and Constructors from a Class object. This method is called by
 978:    * Class.getMethod[s](), Class.getField[s](), Class.getConstructor[s],
 979:    * Class.getDeclaredMethod[s](), Class.getDeclaredField[s](), and
 980:    * Class.getDeclaredConstructor[s](). The default implementation allows
 981:    * PUBLIC access, and access to classes defined by the same classloader as
 982:    * the code performing the reflection. Otherwise, it checks
 983:    * <code>RuntimePermission("accessDeclaredMembers")</code>. If you override
 984:    * this, do not call <code>super.checkMemberAccess</code>, as this would
 985:    * mess up the stack depth check that determines the ClassLoader requesting
 986:    * the access.
 987:    *
 988:    * @param c the Class to check
 989:    * @param memberType either DECLARED or PUBLIC
 990:    * @throws SecurityException if permission is denied, including when
 991:    *         memberType is not DECLARED or PUBLIC
 992:    * @throws NullPointerException if c is null
 993:    * @see Class
 994:    * @see Member#DECLARED
 995:    * @see Member#PUBLIC
 996:    * @since 1.1
 997:    */
 998:   public void checkMemberAccess(Class<?> c, int memberType)
 999:   {
1000:     if (c == null)
1001:       throw new NullPointerException();
1002:     if (memberType == Member.PUBLIC)
1003:       return;
1004:     // XXX Allow access to classes created by same classloader before next
1005:     // check.
1006:     checkPermission(new RuntimePermission("accessDeclaredMembers"));
1007:   }
1008: 
1009:   /**
1010:    * Test whether a particular security action may be taken. The default
1011:    * implementation checks <code>SecurityPermission(action)</code>. If you
1012:    * override this, call <code>super.checkSecurityAccess</code> rather than
1013:    * throwing an exception.
1014:    *
1015:    * @param action the desired action to take
1016:    * @throws SecurityException if permission is denied
1017:    * @throws NullPointerException if action is null
1018:    * @throws IllegalArgumentException if action is ""
1019:    * @since 1.1
1020:    */
1021:   public void checkSecurityAccess(String action)
1022:   {
1023:     checkPermission(new SecurityPermission(action));
1024:   }
1025: 
1026:   /**
1027:    * Get the ThreadGroup that a new Thread should belong to by default. Called
1028:    * by Thread.Thread(). The default implementation returns the current
1029:    * ThreadGroup of the current Thread. <STRONG>Spec Note:</STRONG> it is not
1030:    * clear whether the new Thread is guaranteed to pass the
1031:    * checkAccessThreadGroup() test when using this ThreadGroup, but I presume
1032:    * so.
1033:    *
1034:    * @return the ThreadGroup to put the new Thread into
1035:    * @since 1.1
1036:    */
1037:   public ThreadGroup getThreadGroup()
1038:   {
1039:     return Thread.currentThread().getThreadGroup();
1040:   }
1041: 
1042:   /**
1043:    * Helper that checks a comma-separated list of restricted packages, from
1044:    * <code>Security.getProperty("package.definition")</code>, for the given
1045:    * package access permission. If packageName starts with or equals any
1046:    * restricted package, it checks
1047:    * <code>RuntimePermission(permission + packageName)</code>.
1048:    *
1049:    * @param packageName the package name to check access to
1050:    * @param restriction "package.access" or "package.definition"
1051:    * @param permission the base permission, including the '.'
1052:    * @throws SecurityException if permission is denied
1053:    * @throws NullPointerException if packageName is null
1054:    * @see #checkPackageAccess(String)
1055:    * @see #checkPackageDefinition(String)
1056:    */
1057:   void checkPackageList(String packageName, final String restriction,
1058:                         String permission)
1059:   {
1060:     if (packageName == null)
1061:       throw new NullPointerException();
1062: 
1063:     String list = (String)AccessController.doPrivileged(new PrivilegedAction()
1064:       {
1065:     public Object run()
1066:         {
1067:       return Security.getProperty(restriction);
1068:     }
1069:       });
1070: 
1071:     if (list == null || list.equals(""))
1072:       return;
1073: 
1074:     String packageNamePlusDot = packageName + ".";
1075: 
1076:     StringTokenizer st = new StringTokenizer(list, ",");
1077:     while (st.hasMoreTokens())
1078:       {
1079:     if (packageNamePlusDot.startsWith(st.nextToken()))
1080:       {
1081:         Permission p = new RuntimePermission(permission + packageName);
1082:         checkPermission(p);
1083:         return;
1084:       }
1085:       }
1086:   }
1087: }