Source for java.lang.SecurityManager

   1: /* SecurityManager.java -- security checks for privileged actions
   2:    Copyright (C) 1998, 1999, 2001, 2002, 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:     SecurityManager sm = System.getSecurityManager();
 171:     if (sm != null)
 172:       sm.checkPermission(new RuntimePermission("createSecurityManager"));
 173:   }
 174: 
 175:   /**
 176:    * Tells whether or not the SecurityManager is currently performing a
 177:    * security check.
 178:    *
 179:    * @return true if the SecurityManager is in a security check
 180:    * @see #inCheck
 181:    * @deprecated use {@link #checkPermission(Permission)} instead
 182:    */
 183:   public boolean getInCheck()
 184:   {
 185:     return inCheck;
 186:   }
 187: 
 188:   /**
 189:    * Get a list of all the classes currently executing methods on the Java
 190:    * stack.  getClassContext()[0] is the currently executing method (ie. the
 191:    * class that CALLED getClassContext, not SecurityManager).
 192:    *
 193:    * @return an array of classes on the Java execution stack
 194:    */
 195:   protected Class[] getClassContext()
 196:   {
 197:     Class[] stack1 = VMStackWalker.getClassContext();
 198:     Class[] stack2 = new Class[stack1.length - 1];
 199:     System.arraycopy(stack1, 1, stack2, 0, stack1.length - 1);
 200:     return stack2;
 201:   }
 202: 
 203:   /**
 204:    * Find the ClassLoader of the first non-system class on the execution
 205:    * stack. A non-system class is one whose ClassLoader is not equal to
 206:    * {@link ClassLoader#getSystemClassLoader()} or its ancestors. This
 207:    * will return null in three cases:
 208:    *
 209:    * <ul>
 210:    * <li>All methods on the stack are from system classes</li>
 211:    * <li>All methods on the stack up to the first "privileged" caller, as
 212:    *  created by {@link AccessController#doPrivileged(PrivilegedAction)},
 213:    *  are from system classes</li>
 214:    * <li>A check of <code>java.security.AllPermission</code> succeeds.</li>
 215:    * </ul>
 216:    * 
 217:    * @return the most recent non-system ClassLoader on the execution stack
 218:    * @deprecated use {@link #checkPermission(Permission)} instead
 219:    */
 220:   protected ClassLoader currentClassLoader()
 221:   {
 222:     Class cl = currentLoadedClass();
 223:     return cl != null ? cl.getClassLoader() : null;
 224:   }
 225: 
 226:   /**
 227:    * Find the first non-system class on the execution stack. A non-system
 228:    * class is one whose ClassLoader is not equal to
 229:    * {@link ClassLoader#getSystemClassLoader()} or its ancestors. This
 230:    * will return null in three cases:
 231:    *
 232:    * <ul>
 233:    * <li>All methods on the stack are from system classes</li>
 234:    * <li>All methods on the stack up to the first "privileged" caller, as
 235:    *  created by {@link AccessController#doPrivileged(PrivilegedAction)},
 236:    *  are from system classes</li>
 237:    * <li>A check of <code>java.security.AllPermission</code> succeeds.</li>
 238:    * </ul>
 239:    * 
 240:    * @return the most recent non-system Class on the execution stack
 241:    * @deprecated use {@link #checkPermission(Permission)} instead
 242:    */
 243:   protected Class currentLoadedClass()
 244:   {
 245:     int i = classLoaderDepth();
 246:     return i >= 0 ? getClassContext()[i] : null;
 247:   }
 248: 
 249:   /**
 250:    * Get the depth of a particular class on the execution stack.
 251:    *
 252:    * @param className the fully-qualified name to search for
 253:    * @return the index of the class on the stack, or -1
 254:    * @deprecated use {@link #checkPermission(Permission)} instead
 255:    */
 256:   protected int classDepth(String className)
 257:   {
 258:     Class[] c = getClassContext();
 259:     for (int i = 0; i < c.length; i++)
 260:       if (className.equals(c[i].getName()))
 261:         return i;
 262:     return -1;
 263:   }
 264: 
 265:   /**
 266:    * Get the depth on the execution stack of the most recent non-system class.
 267:    * A non-system class is one whose ClassLoader is not equal to
 268:    * {@link ClassLoader#getSystemClassLoader()} or its ancestors. This
 269:    * will return -1 in three cases:
 270:    *
 271:    * <ul>
 272:    * <li>All methods on the stack are from system classes</li>
 273:    * <li>All methods on the stack up to the first "privileged" caller, as
 274:    *  created by {@link AccessController#doPrivileged(PrivilegedAction)},
 275:    *  are from system classes</li>
 276:    * <li>A check of <code>java.security.AllPermission</code> succeeds.</li>
 277:    * </ul>
 278:    * 
 279:    * @return the index of the most recent non-system Class on the stack
 280:    * @deprecated use {@link #checkPermission(Permission)} instead
 281:    */
 282:   protected int classLoaderDepth()
 283:   {
 284:     try
 285:       {
 286:         checkPermission(new AllPermission());
 287:       }
 288:     catch (SecurityException e)
 289:       {
 290:         Class[] c = getClassContext();
 291:         for (int i = 0; i < c.length; i++)
 292:           if (c[i].getClassLoader() != null)
 293:             // XXX Check if c[i] is AccessController, or a system class.
 294:             return i;
 295:       }
 296:     return -1;
 297:   }
 298: 
 299:   /**
 300:    * Tell whether the specified class is on the execution stack.
 301:    *
 302:    * @param className the fully-qualified name of the class to find
 303:    * @return whether the specified class is on the execution stack
 304:    * @deprecated use {@link #checkPermission(Permission)} instead
 305:    */
 306:   protected boolean inClass(String className)
 307:   {
 308:     return classDepth(className) != -1;
 309:   }
 310: 
 311:   /**
 312:    * Tell whether there is a class loaded with an explicit ClassLoader on
 313:    * the stack.
 314:    *
 315:    * @return whether a class with an explicit ClassLoader is on the stack
 316:    * @deprecated use {@link #checkPermission(Permission)} instead
 317:    */
 318:   protected boolean inClassLoader()
 319:   {
 320:     return classLoaderDepth() != -1;
 321:   }
 322: 
 323:   /**
 324:    * Get an implementation-dependent Object that contains enough information
 325:    * about the current environment to be able to perform standard security
 326:    * checks later.  This is used by trusted methods that need to verify that
 327:    * their callers have sufficient access to perform certain operations.
 328:    *
 329:    * <p>Currently the only methods that use this are checkRead() and
 330:    * checkConnect(). The default implementation returns an
 331:    * <code>AccessControlContext</code>.
 332:    *
 333:    * @return a security context
 334:    * @see #checkConnect(String, int, Object)
 335:    * @see #checkRead(String, Object)
 336:    * @see AccessControlContext
 337:    * @see AccessController#getContext()
 338:    */
 339:   public Object getSecurityContext()
 340:   {
 341:     return AccessController.getContext();
 342:   }
 343: 
 344:   /**
 345:    * Check if the current thread is allowed to perform an operation that
 346:    * requires the specified <code>Permission</code>. This defaults to
 347:    * <code>AccessController.checkPermission</code>.
 348:    *
 349:    * @param perm the <code>Permission</code> required
 350:    * @throws SecurityException if permission is denied
 351:    * @throws NullPointerException if perm is null
 352:    * @since 1.2
 353:    */
 354:   public void checkPermission(Permission perm)
 355:   {
 356:     AccessController.checkPermission(perm);
 357:   }
 358: 
 359:   /**
 360:    * Check if the current thread is allowed to perform an operation that
 361:    * requires the specified <code>Permission</code>. This is done in a
 362:    * context previously returned by <code>getSecurityContext()</code>. The
 363:    * default implementation expects context to be an AccessControlContext,
 364:    * and it calls <code>AccessControlContext.checkPermission(perm)</code>.
 365:    *
 366:    * @param perm the <code>Permission</code> required
 367:    * @param context a security context
 368:    * @throws SecurityException if permission is denied, or if context is
 369:    *         not an AccessControlContext
 370:    * @throws NullPointerException if perm is null
 371:    * @see #getSecurityContext()
 372:    * @see AccessControlContext#checkPermission(Permission)
 373:    * @since 1.2
 374:    */
 375:   public void checkPermission(Permission perm, Object context)
 376:   {
 377:     if (! (context instanceof AccessControlContext))
 378:       throw new SecurityException("Missing context");
 379:     ((AccessControlContext) context).checkPermission(perm);
 380:   }
 381: 
 382:   /**
 383:    * Check if the current thread is allowed to create a ClassLoader. This
 384:    * method is called from ClassLoader.ClassLoader(), and checks
 385:    * <code>RuntimePermission("createClassLoader")</code>. If you override
 386:    * this, you should call <code>super.checkCreateClassLoader()</code> rather
 387:    * than throwing an exception.
 388:    *
 389:    * @throws SecurityException if permission is denied
 390:    * @see ClassLoader#ClassLoader()
 391:    */
 392:   public void checkCreateClassLoader()
 393:   {
 394:     checkPermission(new RuntimePermission("createClassLoader"));
 395:   }
 396: 
 397:   /**
 398:    * Check if the current thread is allowed to modify another Thread. This is
 399:    * called by Thread.stop(), suspend(), resume(), interrupt(), destroy(),
 400:    * setPriority(), setName(), and setDaemon(). The default implementation
 401:    * checks <code>RuntimePermission("modifyThread")</code> on system threads
 402:    * (ie. threads in ThreadGroup with a null parent), and returns silently on
 403:    * other threads.
 404:    *
 405:    * <p>If you override this, you must do two things. First, call
 406:    * <code>super.checkAccess(t)</code>, to make sure you are not relaxing
 407:    * requirements. Second, if the calling thread has
 408:    * <code>RuntimePermission("modifyThread")</code>, return silently, so that
 409:    * core classes (the Classpath library!) can modify any thread.
 410:    *
 411:    * @param thread the other Thread to check
 412:    * @throws SecurityException if permission is denied
 413:    * @throws NullPointerException if thread is null
 414:    * @see Thread#stop()
 415:    * @see Thread#suspend()
 416:    * @see Thread#resume()
 417:    * @see Thread#setPriority(int)
 418:    * @see Thread#setName(String)
 419:    * @see Thread#setDaemon(boolean)
 420:    */
 421:   public void checkAccess(Thread thread)
 422:   {
 423:     if (thread.getThreadGroup() != null 
 424:     && thread.getThreadGroup().getParent() == null)
 425:       checkPermission(new RuntimePermission("modifyThread"));
 426:   }
 427: 
 428:   /**
 429:    * Check if the current thread is allowed to modify a ThreadGroup. This is
 430:    * called by Thread.Thread() (to add a thread to the ThreadGroup),
 431:    * ThreadGroup.ThreadGroup() (to add this ThreadGroup to a parent),
 432:    * ThreadGroup.stop(), suspend(), resume(), interrupt(), destroy(),
 433:    * setDaemon(), and setMaxPriority(). The default implementation
 434:    * checks <code>RuntimePermission("modifyThread")</code> on the system group
 435:    * (ie. the one with a null parent), and returns silently on other groups.
 436:    *
 437:    * <p>If you override this, you must do two things. First, call
 438:    * <code>super.checkAccess(t)</code>, to make sure you are not relaxing
 439:    * requirements. Second, if the calling thread has
 440:    * <code>RuntimePermission("modifyThreadGroup")</code>, return silently,
 441:    * so that core classes (the Classpath library!) can modify any thread.
 442:    *
 443:    * @param g the ThreadGroup to check
 444:    * @throws SecurityException if permission is denied
 445:    * @throws NullPointerException if g is null
 446:    * @see Thread#Thread()
 447:    * @see ThreadGroup#ThreadGroup(String)
 448:    * @see ThreadGroup#stop()
 449:    * @see ThreadGroup#suspend()
 450:    * @see ThreadGroup#resume()
 451:    * @see ThreadGroup#interrupt()
 452:    * @see ThreadGroup#setDaemon(boolean)
 453:    * @see ThreadGroup#setMaxPriority(int)
 454:    */
 455:   public void checkAccess(ThreadGroup g)
 456:   {
 457:     if (g.getParent() == null)
 458:       checkPermission(new RuntimePermission("modifyThreadGroup"));
 459:   }
 460: 
 461:   /**
 462:    * Check if the current thread is allowed to exit the JVM with the given
 463:    * status. This method is called from Runtime.exit() and Runtime.halt().
 464:    * The default implementation checks
 465:    * <code>RuntimePermission("exitVM")</code>. If you override this, call
 466:    * <code>super.checkExit</code> rather than throwing an exception.
 467:    *
 468:    * @param status the status to exit with
 469:    * @throws SecurityException if permission is denied
 470:    * @see Runtime#exit(int)
 471:    * @see Runtime#halt(int)
 472:    */
 473:   public void checkExit(int status)
 474:   {
 475:     checkPermission(new RuntimePermission("exitVM"));
 476:   }
 477: 
 478:   /**
 479:    * Check if the current thread is allowed to execute the given program. This
 480:    * method is called from Runtime.exec(). If the name is an absolute path,
 481:    * the default implementation checks
 482:    * <code>FilePermission(program, "execute")</code>, otherwise it checks
 483:    * <code>FilePermission("&lt;&lt;ALL FILES&gt;&gt;", "execute")</code>. If
 484:    * you override this, call <code>super.checkExec</code> rather than
 485:    * throwing an exception.
 486:    *
 487:    * @param program the name of the program to exec
 488:    * @throws SecurityException if permission is denied
 489:    * @throws NullPointerException if program is null
 490:    * @see Runtime#exec(String[], String[], File)
 491:    */
 492:   public void checkExec(String program)
 493:   {
 494:     if (! program.equals(new File(program).getAbsolutePath()))
 495:       program = "<<ALL FILES>>";
 496:     checkPermission(new FilePermission(program, "execute"));
 497:   }
 498: 
 499:   /**
 500:    * Check if the current thread is allowed to link in the given native
 501:    * library. This method is called from Runtime.load() (and hence, by
 502:    * loadLibrary() as well). The default implementation checks
 503:    * <code>RuntimePermission("loadLibrary." + filename)</code>. If you
 504:    * override this, call <code>super.checkLink</code> rather than throwing
 505:    * an exception.
 506:    *
 507:    * @param filename the full name of the library to load
 508:    * @throws SecurityException if permission is denied
 509:    * @throws NullPointerException if filename is null
 510:    * @see Runtime#load(String)
 511:    */
 512:   public void checkLink(String filename)
 513:   {
 514:     // Use the toString() hack to do the null check.
 515:     checkPermission(new RuntimePermission("loadLibrary."
 516:                                           + filename.toString()));
 517:   }
 518: 
 519:   /**
 520:    * Check if the current thread is allowed to read the given file using the
 521:    * FileDescriptor. This method is called from
 522:    * FileInputStream.FileInputStream(). The default implementation checks
 523:    * <code>RuntimePermission("readFileDescriptor")</code>. If you override
 524:    * this, call <code>super.checkRead</code> rather than throwing an
 525:    * exception.
 526:    *
 527:    * @param desc the FileDescriptor representing the file to access
 528:    * @throws SecurityException if permission is denied
 529:    * @throws NullPointerException if desc is null
 530:    * @see FileInputStream#FileInputStream(FileDescriptor)
 531:    */
 532:   public void checkRead(FileDescriptor desc)
 533:   {
 534:     if (desc == null)
 535:       throw new NullPointerException();
 536:     checkPermission(new RuntimePermission("readFileDescriptor"));
 537:   }
 538: 
 539:   /**
 540:    * Check if the current thread is allowed to read the given file. This
 541:    * method is called from FileInputStream.FileInputStream(),
 542:    * RandomAccessFile.RandomAccessFile(), File.exists(), canRead(), isFile(),
 543:    * isDirectory(), lastModified(), length() and list(). The default
 544:    * implementation checks <code>FilePermission(filename, "read")</code>. If
 545:    * you override this, call <code>super.checkRead</code> rather than
 546:    * throwing an exception.
 547:    *
 548:    * @param filename the full name of the file to access
 549:    * @throws SecurityException if permission is denied
 550:    * @throws NullPointerException if filename is null
 551:    * @see File
 552:    * @see FileInputStream#FileInputStream(String)
 553:    * @see RandomAccessFile#RandomAccessFile(String, String)
 554:    */
 555:   public void checkRead(String filename)
 556:   {
 557:     checkPermission(new FilePermission(filename, "read"));
 558:   }
 559: 
 560:   /**
 561:    * Check if the current thread is allowed to read the given file. using the
 562:    * given security context. The context must be a result of a previous call
 563:    * to <code>getSecurityContext()</code>. The default implementation checks
 564:    * <code>AccessControlContext.checkPermission(new FilePermission(filename,
 565:    * "read"))</code>. If you override this, call <code>super.checkRead</code>
 566:    * rather than throwing an exception.
 567:    *
 568:    * @param filename the full name of the file to access
 569:    * @param context the context to determine access for
 570:    * @throws SecurityException if permission is denied, or if context is
 571:    *         not an AccessControlContext
 572:    * @throws NullPointerException if filename is null
 573:    * @see #getSecurityContext()
 574:    * @see AccessControlContext#checkPermission(Permission)
 575:    */
 576:   public void checkRead(String filename, Object context)
 577:   {
 578:     if (! (context instanceof AccessControlContext))
 579:       throw new SecurityException("Missing context");
 580:     AccessControlContext ac = (AccessControlContext) context;
 581:     ac.checkPermission(new FilePermission(filename, "read"));
 582:   }
 583: 
 584:   /**
 585:    * Check if the current thread is allowed to write the given file using the
 586:    * FileDescriptor. This method is called from
 587:    * FileOutputStream.FileOutputStream(). The default implementation checks
 588:    * <code>RuntimePermission("writeFileDescriptor")</code>. If you override
 589:    * this, call <code>super.checkWrite</code> rather than throwing an
 590:    * exception.
 591:    *
 592:    * @param desc the FileDescriptor representing the file to access
 593:    * @throws SecurityException if permission is denied
 594:    * @throws NullPointerException if desc is null
 595:    * @see FileOutputStream#FileOutputStream(FileDescriptor)
 596:    */
 597:   public void checkWrite(FileDescriptor desc)
 598:   {
 599:     if (desc == null)
 600:       throw new NullPointerException();
 601:     checkPermission(new RuntimePermission("writeFileDescriptor"));
 602:   }
 603: 
 604:   /**
 605:    * Check if the current thread is allowed to write the given file. This
 606:    * method is called from FileOutputStream.FileOutputStream(),
 607:    * RandomAccessFile.RandomAccessFile(), File.canWrite(), mkdir(), and
 608:    * renameTo(). The default implementation checks
 609:    * <code>FilePermission(filename, "write")</code>. If you override this,
 610:    * call <code>super.checkWrite</code> rather than throwing an exception.
 611:    *
 612:    * @param filename the full name of the file to access
 613:    * @throws SecurityException if permission is denied
 614:    * @throws NullPointerException if filename is null
 615:    * @see File
 616:    * @see File#canWrite()
 617:    * @see File#mkdir()
 618:    * @see File#renameTo(File)
 619:    * @see FileOutputStream#FileOutputStream(String)
 620:    * @see RandomAccessFile#RandomAccessFile(String, String)
 621:    */
 622:   public void checkWrite(String filename)
 623:   {
 624:     checkPermission(new FilePermission(filename, "write"));
 625:   }
 626: 
 627:   /**
 628:    * Check if the current thread is allowed to delete the given file. This
 629:    * method is called from File.delete(). The default implementation checks
 630:    * <code>FilePermission(filename, "delete")</code>. If you override this,
 631:    * call <code>super.checkDelete</code> rather than throwing an exception.
 632:    *
 633:    * @param filename the full name of the file to delete
 634:    * @throws SecurityException if permission is denied
 635:    * @throws NullPointerException if filename is null
 636:    * @see File#delete()
 637:    */
 638:   public void checkDelete(String filename)
 639:   {
 640:     checkPermission(new FilePermission(filename, "delete"));
 641:   }
 642: 
 643:   /**
 644:    * Check if the current thread is allowed to connect to a given host on a
 645:    * given port. This method is called from Socket.Socket(). A port number
 646:    * of -1 indicates the caller is attempting to determine an IP address, so
 647:    * the default implementation checks
 648:    * <code>SocketPermission(host, "resolve")</code>. Otherwise, the default
 649:    * implementation checks
 650:    * <code>SocketPermission(host + ":" + port, "connect")</code>. If you
 651:    * override this, call <code>super.checkConnect</code> rather than throwing
 652:    * an exception.
 653:    *
 654:    * @param host the host to connect to
 655:    * @param port the port to connect on
 656:    * @throws SecurityException if permission is denied
 657:    * @throws NullPointerException if host is null
 658:    * @see Socket#Socket()
 659:    */
 660:   public void checkConnect(String host, int port)
 661:   {
 662:     if (port == -1)
 663:       checkPermission(new SocketPermission(host, "resolve"));
 664:     else
 665:       // Use the toString() hack to do the null check.
 666:       checkPermission(new SocketPermission(host.toString() + ":" + port,
 667:                                            "connect"));
 668:   }
 669: 
 670:   /**
 671:    * Check if the current thread is allowed to connect to a given host on a
 672:    * given port, using the given security context. The context must be a
 673:    * result of a previous call to <code>getSecurityContext</code>. A port
 674:    * number of -1 indicates the caller is attempting to determine an IP
 675:    * address, so the default implementation checks
 676:    * <code>AccessControlContext.checkPermission(new SocketPermission(host,
 677:    * "resolve"))</code>. Otherwise, the default implementation checks
 678:    * <code>AccessControlContext.checkPermission(new SocketPermission(host
 679:    * + ":" + port, "connect"))</code>. If you override this, call
 680:    * <code>super.checkConnect</code> rather than throwing an exception.
 681:    *
 682:    * @param host the host to connect to
 683:    * @param port the port to connect on
 684:    * @param context the context to determine access for
 685:    *
 686:    * @throws SecurityException if permission is denied, or if context is
 687:    *         not an AccessControlContext
 688:    * @throws NullPointerException if host is null
 689:    *
 690:    * @see #getSecurityContext()
 691:    * @see AccessControlContext#checkPermission(Permission)
 692:    */
 693:   public void checkConnect(String host, int port, Object context)
 694:   {
 695:     if (! (context instanceof AccessControlContext))
 696:       throw new SecurityException("Missing context");
 697:     AccessControlContext ac = (AccessControlContext) context;
 698:     if (port == -1)
 699:       ac.checkPermission(new SocketPermission(host, "resolve"));
 700:     else
 701:       // Use the toString() hack to do the null check.
 702:       ac.checkPermission(new SocketPermission(host.toString() + ":" + port,
 703:                                               "connect"));
 704:   }
 705: 
 706:   /**
 707:    * Check if the current thread is allowed to listen to a specific port for
 708:    * data. This method is called by ServerSocket.ServerSocket(). The default
 709:    * implementation checks
 710:    * <code>SocketPermission("localhost:" + (port == 0 ? "1024-" : "" + port),
 711:    * "listen")</code>. If you override this, call
 712:    * <code>super.checkListen</code> rather than throwing an exception.
 713:    *
 714:    * @param port the port to listen on
 715:    * @throws SecurityException if permission is denied
 716:    * @see ServerSocket#ServerSocket(int)
 717:    */
 718:   public void checkListen(int port)
 719:   {
 720:     checkPermission(new SocketPermission("localhost:"
 721:                                          + (port == 0 ? "1024-" : "" +port),
 722:                                          "listen"));
 723:   }
 724: 
 725:   /**
 726:    * Check if the current thread is allowed to accept a connection from a
 727:    * particular host on a particular port. This method is called by
 728:    * ServerSocket.implAccept(). The default implementation checks
 729:    * <code>SocketPermission(host + ":" + port, "accept")</code>. If you
 730:    * override this, call <code>super.checkAccept</code> rather than throwing
 731:    * an exception.
 732:    *
 733:    * @param host the host which wishes to connect
 734:    * @param port the port the connection will be on
 735:    * @throws SecurityException if permission is denied
 736:    * @throws NullPointerException if host is null
 737:    * @see ServerSocket#accept()
 738:    */
 739:   public void checkAccept(String host, int port)
 740:   {
 741:     // Use the toString() hack to do the null check.
 742:     checkPermission(new SocketPermission(host.toString() + ":" + port,
 743:                                          "accept"));
 744:   }
 745: 
 746:   /**
 747:    * Check if the current thread is allowed to read and write multicast to
 748:    * a particular address. The default implementation checks
 749:    * <code>SocketPermission(addr.getHostAddress(), "accept,connect")</code>.
 750:    * If you override this, call <code>super.checkMulticast</code> rather than
 751:    * throwing an exception.
 752:    *
 753:    * @param addr the address to multicast to
 754:    * @throws SecurityException if permission is denied
 755:    * @throws NullPointerException if host is null
 756:    * @since 1.1
 757:    */
 758:   public void checkMulticast(InetAddress addr)
 759:   {
 760:     checkPermission(new SocketPermission(addr.getHostAddress(),
 761:                                          "accept,connect"));
 762:   }
 763: 
 764:   /**
 765:    *Check if the current thread is allowed to read and write multicast to
 766:    * a particular address with a particular ttl (time-to-live) value. The
 767:    * default implementation ignores ttl, and checks
 768:    * <code>SocketPermission(addr.getHostAddress(), "accept,connect")</code>.
 769:    * If you override this, call <code>super.checkMulticast</code> rather than
 770:    * throwing an exception.
 771:    *
 772:    * @param addr the address to multicast to
 773:    * @param ttl value in use for multicast send
 774:    * @throws SecurityException if permission is denied
 775:    * @throws NullPointerException if host is null
 776:    * @since 1.1
 777:    * @deprecated use {@link #checkPermission(Permission)} instead
 778:    */
 779:   public void checkMulticast(InetAddress addr, byte ttl)
 780:   {
 781:     checkPermission(new SocketPermission(addr.getHostAddress(),
 782:                                          "accept,connect"));
 783:   }
 784: 
 785:   /**
 786:    * Check if the current thread is allowed to read or write all the system
 787:    * properties at once. This method is called by System.getProperties()
 788:    * and setProperties(). The default implementation checks
 789:    * <code>PropertyPermission("*", "read,write")</code>. If you override
 790:    * this, call <code>super.checkPropertiesAccess</code> rather than
 791:    * throwing an exception.
 792:    *
 793:    * @throws SecurityException if permission is denied
 794:    * @see System#getProperties()
 795:    * @see System#setProperties(Properties)
 796:    */
 797:   public void checkPropertiesAccess()
 798:   {
 799:     checkPermission(new PropertyPermission("*", "read,write"));
 800:   }
 801: 
 802:   /**
 803:    * Check if the current thread is allowed to read a particular system
 804:    * property (writes are checked directly via checkPermission). This method
 805:    * is called by System.getProperty() and setProperty(). The default
 806:    * implementation checks <code>PropertyPermission(key, "read")</code>. If
 807:    * you override this, call <code>super.checkPropertyAccess</code> rather
 808:    * than throwing an exception.
 809:    *
 810:    * @param key the key of the property to check
 811:    *
 812:    * @throws SecurityException if permission is denied
 813:    * @throws NullPointerException if key is null
 814:    * @throws IllegalArgumentException if key is ""
 815:    *
 816:    * @see System#getProperty(String)
 817:    */
 818:   public void checkPropertyAccess(String key)
 819:   {
 820:     checkPermission(new PropertyPermission(key, "read"));
 821:   }
 822: 
 823:   /**
 824:    * Check if the current thread is allowed to create a top-level window. If
 825:    * it is not, the operation should still go through, but some sort of
 826:    * nonremovable warning should be placed on the window to show that it
 827:    * is untrusted. This method is called by Window.Window(). The default
 828:    * implementation checks
 829:    * <code>AWTPermission("showWindowWithoutWarningBanner")</code>, and returns
 830:    * true if no exception was thrown. If you override this, use
 831:    * <code>return super.checkTopLevelWindow</code> rather than returning
 832:    * false.
 833:    *
 834:    * @param window the window to create
 835:    * @return true if there is permission to show the window without warning
 836:    * @throws NullPointerException if window is null
 837:    * @see java.awt.Window#Window(java.awt.Frame)
 838:    */
 839:   public boolean checkTopLevelWindow(Object window)
 840:   {
 841:     if (window == null)
 842:       throw new NullPointerException();
 843:     try
 844:       {
 845:         checkPermission(new AWTPermission("showWindowWithoutWarningBanner"));
 846:         return true;
 847:       }
 848:     catch (SecurityException e)
 849:       {
 850:         return false;
 851:       }
 852:   }
 853: 
 854:   /**
 855:    * Check if the current thread is allowed to create a print job. This
 856:    * method is called by Toolkit.getPrintJob(). The default implementation
 857:    * checks <code>RuntimePermission("queuePrintJob")</code>. If you override
 858:    * this, call <code>super.checkPrintJobAccess</code> rather than throwing
 859:    * an exception.
 860:    *
 861:    * @throws SecurityException if permission is denied
 862:    * @see java.awt.Toolkit#getPrintJob(java.awt.Frame, String, Properties)
 863:    * @since 1.1
 864:    */
 865:   public void checkPrintJobAccess()
 866:   {
 867:     checkPermission(new RuntimePermission("queuePrintJob"));
 868:   }
 869: 
 870:   /**
 871:    * Check if the current thread is allowed to use the system clipboard. This
 872:    * method is called by Toolkit.getSystemClipboard(). The default
 873:    * implementation checks <code>AWTPermission("accessClipboard")</code>. If
 874:    * you override this, call <code>super.checkSystemClipboardAccess</code>
 875:    * rather than throwing an exception.
 876:    *
 877:    * @throws SecurityException if permission is denied
 878:    * @see java.awt.Toolkit#getSystemClipboard()
 879:    * @since 1.1
 880:    */
 881:   public void checkSystemClipboardAccess()
 882:   {
 883:     checkPermission(new AWTPermission("accessClipboard"));
 884:   }
 885: 
 886:   /**
 887:    * Check if the current thread is allowed to use the AWT event queue. This
 888:    * method is called by Toolkit.getSystemEventQueue(). The default
 889:    * implementation checks <code>AWTPermission("accessEventQueue")</code>.
 890:    * you override this, call <code>super.checkAwtEventQueueAccess</code>
 891:    * rather than throwing an exception.
 892:    *
 893:    * @throws SecurityException if permission is denied
 894:    * @see java.awt.Toolkit#getSystemEventQueue()
 895:    * @since 1.1
 896:    */
 897:   public void checkAwtEventQueueAccess()
 898:   {
 899:     checkPermission(new AWTPermission("accessEventQueue"));
 900:   }
 901: 
 902:   /**
 903:    * Check if the current thread is allowed to access the specified package
 904:    * at all. This method is called by ClassLoader.loadClass() in user-created
 905:    * ClassLoaders. The default implementation gets a list of all restricted
 906:    * packages, via <code>Security.getProperty("package.access")</code>. Then,
 907:    * if packageName starts with or equals any restricted package, it checks
 908:    * <code>RuntimePermission("accessClassInPackage." + packageName)</code>.
 909:    * If you override this, you should call
 910:    * <code>super.checkPackageAccess</code> before doing anything else.
 911:    *
 912:    * @param packageName the package name to check access to
 913:    * @throws SecurityException if permission is denied
 914:    * @throws NullPointerException if packageName is null
 915:    * @see ClassLoader#loadClass(String, boolean)
 916:    * @see Security#getProperty(String)
 917:    */
 918:   public void checkPackageAccess(String packageName)
 919:   {
 920:     checkPackageList(packageName, "package.access", "accessClassInPackage.");
 921:   }
 922: 
 923:   /**
 924:    * Check if the current thread is allowed to define a class into the
 925:    * specified package. This method is called by ClassLoader.loadClass() in
 926:    * user-created ClassLoaders. The default implementation gets a list of all
 927:    * restricted packages, via
 928:    * <code>Security.getProperty("package.definition")</code>. Then, if
 929:    * packageName starts with or equals any restricted package, it checks
 930:    * <code>RuntimePermission("defineClassInPackage." + packageName)</code>.
 931:    * If you override this, you should call
 932:    * <code>super.checkPackageDefinition</code> before doing anything else.
 933:    *
 934:    * @param packageName the package name to check access to
 935:    * @throws SecurityException if permission is denied
 936:    * @throws NullPointerException if packageName is null
 937:    * @see ClassLoader#loadClass(String, boolean)
 938:    * @see Security#getProperty(String)
 939:    */
 940:   public void checkPackageDefinition(String packageName)
 941:   {
 942:     checkPackageList(packageName, "package.definition", "defineClassInPackage.");
 943:   }
 944: 
 945:   /**
 946:    * Check if the current thread is allowed to set the current socket factory.
 947:    * This method is called by Socket.setSocketImplFactory(),
 948:    * ServerSocket.setSocketFactory(), and URL.setURLStreamHandlerFactory().
 949:    * The default implementation checks
 950:    * <code>RuntimePermission("setFactory")</code>. If you override this, call
 951:    * <code>super.checkSetFactory</code> rather than throwing an exception.
 952:    *
 953:    * @throws SecurityException if permission is denied
 954:    * @see Socket#setSocketImplFactory(SocketImplFactory)
 955:    * @see ServerSocket#setSocketFactory(SocketImplFactory)
 956:    * @see URL#setURLStreamHandlerFactory(URLStreamHandlerFactory)
 957:    */
 958:   public void checkSetFactory()
 959:   {
 960:     checkPermission(new RuntimePermission("setFactory"));
 961:   }
 962: 
 963:   /**
 964:    * Check if the current thread is allowed to get certain types of Methods,
 965:    * Fields and Constructors from a Class object. This method is called by
 966:    * Class.getMethod[s](), Class.getField[s](), Class.getConstructor[s],
 967:    * Class.getDeclaredMethod[s](), Class.getDeclaredField[s](), and
 968:    * Class.getDeclaredConstructor[s](). The default implementation allows
 969:    * PUBLIC access, and access to classes defined by the same classloader as
 970:    * the code performing the reflection. Otherwise, it checks
 971:    * <code>RuntimePermission("accessDeclaredMembers")</code>. If you override
 972:    * this, do not call <code>super.checkMemberAccess</code>, as this would
 973:    * mess up the stack depth check that determines the ClassLoader requesting
 974:    * the access.
 975:    *
 976:    * @param c the Class to check
 977:    * @param memberType either DECLARED or PUBLIC
 978:    * @throws SecurityException if permission is denied, including when
 979:    *         memberType is not DECLARED or PUBLIC
 980:    * @throws NullPointerException if c is null
 981:    * @see Class
 982:    * @see Member#DECLARED
 983:    * @see Member#PUBLIC
 984:    * @since 1.1
 985:    */
 986:   public void checkMemberAccess(Class c, int memberType)
 987:   {
 988:     if (c == null)
 989:       throw new NullPointerException();
 990:     if (memberType == Member.PUBLIC)
 991:       return;
 992:     // XXX Allow access to classes created by same classloader before next
 993:     // check.
 994:     checkPermission(new RuntimePermission("accessDeclaredMembers"));
 995:   }
 996: 
 997:   /**
 998:    * Test whether a particular security action may be taken. The default
 999:    * implementation checks <code>SecurityPermission(action)</code>. If you
1000:    * override this, call <code>super.checkSecurityAccess</code> rather than
1001:    * throwing an exception.
1002:    *
1003:    * @param action the desired action to take
1004:    * @throws SecurityException if permission is denied
1005:    * @throws NullPointerException if action is null
1006:    * @throws IllegalArgumentException if action is ""
1007:    * @since 1.1
1008:    */
1009:   public void checkSecurityAccess(String action)
1010:   {
1011:     checkPermission(new SecurityPermission(action));
1012:   }
1013: 
1014:   /**
1015:    * Get the ThreadGroup that a new Thread should belong to by default. Called
1016:    * by Thread.Thread(). The default implementation returns the current
1017:    * ThreadGroup of the current Thread. <STRONG>Spec Note:</STRONG> it is not
1018:    * clear whether the new Thread is guaranteed to pass the
1019:    * checkAccessThreadGroup() test when using this ThreadGroup, but I presume
1020:    * so.
1021:    *
1022:    * @return the ThreadGroup to put the new Thread into
1023:    * @since 1.1
1024:    */
1025:   public ThreadGroup getThreadGroup()
1026:   {
1027:     return Thread.currentThread().getThreadGroup();
1028:   }
1029: 
1030:   /**
1031:    * Helper that checks a comma-separated list of restricted packages, from
1032:    * <code>Security.getProperty("package.definition")</code>, for the given
1033:    * package access permission. If packageName starts with or equals any
1034:    * restricted package, it checks
1035:    * <code>RuntimePermission(permission + packageName)</code>.
1036:    *
1037:    * @param packageName the package name to check access to
1038:    * @param restriction "package.access" or "package.definition"
1039:    * @param permission the base permission, including the '.'
1040:    * @throws SecurityException if permission is denied
1041:    * @throws NullPointerException if packageName is null
1042:    * @see #checkPackageAccess(String)
1043:    * @see #checkPackageDefinition(String)
1044:    */
1045:   void checkPackageList(String packageName, final String restriction,
1046:                         String permission)
1047:   {
1048:     if (packageName == null)
1049:       throw new NullPointerException();
1050: 
1051:     String list = (String)AccessController.doPrivileged(new PrivilegedAction()
1052:       {
1053:     public Object run()
1054:         {
1055:       return Security.getProperty(restriction);
1056:     }
1057:       });
1058: 
1059:     if (list == null || list.equals(""))
1060:       return;
1061: 
1062:     String packageNamePlusDot = packageName + ".";
1063: 
1064:     StringTokenizer st = new StringTokenizer(list, ",");
1065:     while (st.hasMoreTokens())
1066:       {
1067:     if (packageNamePlusDot.startsWith(st.nextToken()))
1068:       {
1069:         Permission p = new RuntimePermission(permission + packageName);
1070:         checkPermission(p);
1071:         return;
1072:       }
1073:       }
1074:   }
1075: }