1 /*
2 * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package java.io;
27
28 import java.security.*;
29 import java.util.Enumeration;
30 import java.util.List;
31 import java.util.ArrayList;
32 import java.util.Vector;
33 import java.util.Collections;
34 import java.util.StringJoiner;
35 import sun.security.util.SecurityConstants;
36
37 /**
38 * This class represents access to a file or directory. A FilePermission consists
39 * of a pathname and a set of actions valid for that pathname.
40 * <P>
41 * Pathname is the pathname of the file or directory granted the specified
42 * actions. A pathname that ends in "/*" (where "/" is
43 * the file separator character, <code>File.separatorChar</code>) indicates
44 * all the files and directories contained in that directory. A pathname
45 * that ends with "/-" indicates (recursively) all files
46 * and subdirectories contained in that directory. A pathname consisting of
47 * the special token "<<ALL FILES>>" matches <b>any</b> file.
48 * <P>
49 * Note: A pathname consisting of a single "*" indicates all the files
50 * in the current directory, while a pathname consisting of a single "-"
51 * indicates all the files in the current directory and
52 * (recursively) all files and subdirectories contained in the current
53 * directory.
54 * <P>
55 * The actions to be granted are passed to the constructor in a string containing
56 * a list of one or more comma-separated keywords. The possible keywords are
57 * "read", "write", "execute", "delete", and "readlink". Their meaning is
58 * defined as follows:
59 *
60 * <DL>
61 * <DT> read <DD> read permission
62 * <DT> write <DD> write permission
63 * <DT> execute
64 * <DD> execute permission. Allows <code>Runtime.exec</code> to
65 * be called. Corresponds to <code>SecurityManager.checkExec</code>.
66 * <DT> delete
67 * <DD> delete permission. Allows <code>File.delete</code> to
68 * be called. Corresponds to <code>SecurityManager.checkDelete</code>.
69 * <DT> readlink
70 * <DD> read link permission. Allows the target of a
71 * <a href="../nio/file/package-summary.html#links">symbolic link</a>
72 * to be read by invoking the {@link java.nio.file.Files#readSymbolicLink
73 * readSymbolicLink } method.
74 * </DL>
75 * <P>
76 * The actions string is converted to lowercase before processing.
77 * <P>
78 * Be careful when granting FilePermissions. Think about the implications
79 * of granting read and especially write access to various files and
80 * directories. The "<<ALL FILES>>" permission with write action is
81 * especially dangerous. This grants permission to write to the entire
82 * file system. One thing this effectively allows is replacement of the
83 * system binary, including the JVM runtime environment.
84 *
85 * <p>Please note: Code can always read a file from the same
86 * directory it's in (or a subdirectory of that directory); it does not
87 * need explicit permission to do so.
88 *
89 * @see java.security.Permission
90 * @see java.security.Permissions
91 * @see java.security.PermissionCollection
92 *
93 *
94 * @author Marianne Mueller
95 * @author Roland Schemers
96 * @since 1.2
97 *
98 * @serial exclude
99 */
100
101 public final class FilePermission extends Permission implements Serializable {
102
103 /**
104 * Execute action.
105 */
106 private final static int EXECUTE = 0x1;
107 /**
108 * Write action.
109 */
110 private final static int WRITE = 0x2;
111 /**
112 * Read action.
113 */
114 private final static int READ = 0x4;
115 /**
116 * Delete action.
117 */
118 private final static int DELETE = 0x8;
119 /**
120 * Read link action.
121 */
122 private final static int READLINK = 0x10;
123
124 /**
125 * All actions (read,write,execute,delete,readlink)
126 */
127 private final static int ALL = READ|WRITE|EXECUTE|DELETE|READLINK;
128 /**
129 * No actions.
130 */
131 private final static int NONE = 0x0;
132
133 // the actions mask
134 private transient int mask;
135
136 // does path indicate a directory? (wildcard or recursive)
137 private transient boolean directory;
138
139 // is it a recursive directory specification?
140 private transient boolean recursive;
141
142 /**
143 * the actions string.
144 *
145 * @serial
146 */
147 private String actions; // Left null as long as possible, then
148 // created and re-used in the getAction function.
149
150 // Flags to assist in lazy setting.
151 // Are directory and recursive set?
152 private transient boolean dir_rec_set = false;
153
154 // canonicalized dir path. In the case of
155 // directories, it is the name "/blah/*" or "/blah/-" without
156 // the last character (the "*" or "-").
157
158 private transient String cpath;
159
160 // static Strings used by init(int mask)
161 private static final char RECURSIVE_CHAR = '-';
162 private static final char WILD_CHAR = '*';
163
164 /*
165 public String toString()
166 {
167 StringBuffer sb = new StringBuffer();
168 sb.append("***\n");
169 sb.append("cpath = "+cpath+"\n");
170 sb.append("mask = "+mask+"\n");
171 sb.append("actions = "+getActions()+"\n");
172 sb.append("directory = "+directory+"\n");
173 sb.append("recursive = "+recursive+"\n");
174 sb.append("***\n");
175 return sb.toString();
176 }
177 */
178
179 private static final long serialVersionUID = 7930732926638008763L;
180
181 /**
182 * initialize a FilePermission object. Common to all constructors.
183 * Also called during de-serialization.
184 *
185 * @param mask the actions mask to use.
186 *
187 */
188 private void init(int mask) {
189 if ((mask & ALL) != mask)
190 throw new IllegalArgumentException("invalid actions mask");
191
192 if (mask == NONE)
193 throw new IllegalArgumentException("invalid actions mask");
194
195 if (getName() == null)
196 throw new NullPointerException("name can't be null");
197
198 this.mask = mask;
199 }
200
201 /*
202 * Sets the directory and recursive flag, and does partial processing of the
203 * path name.
204 */
205 private void get_dir_rec() {
206
207 cpath = getName();
208
209 if (cpath.equals("<<ALL FILES>>")) {
210 directory = true;
211 recursive = true;
212 cpath = "";
213 dir_rec_set = true;
214 return;
215 }
216
217 // store only the canonical cpath if possible
218 cpath = AccessController.doPrivileged(new PrivilegedAction<String>() {
219 public String run() {
220 try {
221 String path = cpath;
222 if (cpath.endsWith("*")) {
223 // call getCanonicalPath with a path with wildcard character
224 // replaced to avoid calling it with paths that are
225 // intended to match all entries in a directory
226 path = path.substring(0, path.length()-1) + "-";
227 path = new File(path).getCanonicalPath();
228 return path.substring(0, path.length()-1) + "*";
229 } else {
230 return new File(path).getCanonicalPath();
231 }
232 } catch (IOException ioe) {
233 return cpath;
234 }
235 }
236 });
237
238 int len = cpath.length();
239 char last = ((len > 0) ? cpath.charAt(len - 1) : 0);
240
241 if (last == RECURSIVE_CHAR &&
242 (len == 1 || cpath.charAt(len - 2) == File.separatorChar)) {
243 directory = true;
244 recursive = true;
245 cpath = cpath.substring(0, --len);
246 } else if (last == WILD_CHAR &&
247 (len == 1 || cpath.charAt(len - 2) == File.separatorChar)) {
248 directory = true;
249 //recursive = false;
250 cpath = cpath.substring(0, --len);
251 } else {
252 // overkill since they are initialized to false, but
253 // commented out here to remind us...
254 //directory = false;
255 //recursive = false;
256 }
257
258 // XXX: at this point the path should be absolute. die if it isn't?
259 dir_rec_set = true;
260 }
261
262 /**
263 * Creates a new FilePermission object with the specified actions.
264 * <i>path</i> is the pathname of a file or directory, and <i>actions</i>
265 * contains a comma-separated list of the desired actions granted on the
266 * file or directory. Possible actions are
267 * "read", "write", "execute", "delete", and "readlink".
268 *
269 * <p>A pathname that ends in "/*" (where "/" is
270 * the file separator character, <code>File.separatorChar</code>)
271 * indicates all the files and directories contained in that directory.
272 * A pathname that ends with "/-" indicates (recursively) all files and
273 * subdirectories contained in that directory. The special pathname
274 * "<<ALL FILES>>" matches any file.
275 *
276 * <p>A pathname consisting of a single "*" indicates all the files
277 * in the current directory, while a pathname consisting of a single "-"
278 * indicates all the files in the current directory and
279 * (recursively) all files and subdirectories contained in the current
280 * directory.
281 *
282 * <p>A pathname containing an empty string represents an empty path.
283 *
284 * @param path the pathname of the file/directory.
285 * @param actions the action string.
286 *
287 * @throws IllegalArgumentException
288 * If actions is <code>null</code>, empty or contains an action
289 * other than the specified possible actions.
290 */
291 public FilePermission(String path, String actions) {
292 super(path);
293 init(getMask(actions));
294 }
295
296 /**
297 * Creates a new FilePermission object using an action mask.
298 * More efficient than the FilePermission(String, String) constructor.
299 * Can be used from within
300 * code that needs to create a FilePermission object to pass into the
301 * <code>implies</code> method.
302 *
303 * @param path the pathname of the file/directory.
304 * @param mask the action mask to use.
305 */
306
307 // package private for use by the FilePermissionCollection add method
308 FilePermission(String path, int mask) {
309 super(path);
310 init(mask);
311 }
312
313 /**
314 * Checks if this FilePermission object "implies" the specified permission.
315 * <P>
316 * More specifically, this method returns true if:
317 * <ul>
318 * <li> <i>p</i> is an instanceof FilePermission,
319 * <li> <i>p</i>'s actions are a proper subset of this
320 * object's actions, and
321 * <li> <i>p</i>'s pathname is implied by this object's
322 * pathname. For example, "/tmp/*" implies "/tmp/foo", since
323 * "/tmp/*" encompasses all files in the "/tmp" directory,
324 * including the one named "foo".
325 * </ul>
326 *
327 * @param p the permission to check against.
328 *
329 * @return <code>true</code> if the specified permission is not
330 * <code>null</code> and is implied by this object,
331 * <code>false</code> otherwise.
332 */
333 public boolean implies(Permission p) {
334 if (!(p instanceof FilePermission))
335 return false;
336
337 FilePermission that = (FilePermission) p;
338
339 // we get the effective mask. i.e., the "and" of this and that.
340 // They must be equal to that.mask for implies to return true.
341
342 return ((this.mask & that.mask) == that.mask) && impliesIgnoreMask(that);
343 }
344
345 /**
346 * Checks if the Permission's actions are a proper subset of the
347 * this object's actions. Returns the effective mask iff the
348 * this FilePermission's path also implies that FilePermission's path.
349 *
350 * @param that the FilePermission to check against.
351 * @return the effective mask
352 */
353 boolean impliesIgnoreMask(FilePermission that) {
354 if (this.getName().equals("<<ALL FILES>>"))
355 return true;
356 if (!this.dir_rec_set) this.get_dir_rec();
357 if (!that.dir_rec_set) that.get_dir_rec();
358 if (this.directory) {
359 if (this.recursive) {
360 // make sure that.path is longer then path so
361 // something like /foo/- does not imply /foo
362 if (that.directory) {
363 return (that.cpath.length() >= this.cpath.length()) &&
364 that.cpath.startsWith(this.cpath);
365 } else {
366 return ((that.cpath.length() > this.cpath.length()) &&
367 that.cpath.startsWith(this.cpath));
368 }
369 } else {
370 if (that.directory) {
371 // if the permission passed in is a directory
372 // specification, make sure that a non-recursive
373 // permission (i.e., this object) can't imply a recursive
374 // permission.
375 if (that.recursive)
376 return false;
377 else
378 return (this.cpath.equals(that.cpath));
379 } else {
380 int last = that.cpath.lastIndexOf(File.separatorChar);
381 if (last == -1)
382 return false;
383 else {
384 // this.cpath.equals(that.cpath.substring(0, last+1));
385 // Use regionMatches to avoid creating new string
386 return (this.cpath.length() == (last + 1)) &&
387 this.cpath.regionMatches(0, that.cpath, 0, last+1);
388 }
389 }
390 }
391 } else if (that.directory) {
392 // if this is NOT recursive/wildcarded,
393 // do not let it imply a recursive/wildcarded permission
394 return false;
395 } else {
396 return (this.cpath.equals(that.cpath));
397 }
398 }
399
400 /**
401 * Checks two FilePermission objects for equality. Checks that <i>obj</i> is
402 * a FilePermission, and has the same pathname and actions as this object.
403 *
404 * @param obj the object we are testing for equality with this object.
405 * @return <code>true</code> if obj is a FilePermission, and has the same
406 * pathname and actions as this FilePermission object,
407 * <code>false</code> otherwise.
408 */
409 public boolean equals(Object obj) {
410 if (obj == this)
411 return true;
412
413 if (! (obj instanceof FilePermission))
414 return false;
415
416 FilePermission that = (FilePermission) obj;
417
418 if (!this.dir_rec_set) this.get_dir_rec();
419 if (!that.dir_rec_set) that.get_dir_rec();
420 return (this.mask == that.mask) &&
421 this.cpath.equals(that.cpath) &&
422 (this.directory == that.directory) &&
423 (this.recursive == that.recursive);
424 }
425
426 /**
427 * Returns the hash code value for this object.
428 *
429 * @return a hash code value for this object.
430 */
431 public int hashCode() {
432 return 0;
433 }
434
435 /**
436 * Converts an actions String to an actions mask.
437 *
438 * @param actions the action string.
439 * @return the actions mask.
440 */
441 private static int getMask(String actions) {
442 int mask = NONE;
443
444 // Null action valid?
445 if (actions == null) {
446 return mask;
447 }
448
449 // Use object identity comparison against known-interned strings for
450 // performance benefit (these values are used heavily within the JDK).
451 if (actions == SecurityConstants.FILE_READ_ACTION) {
452 return READ;
453 } else if (actions == SecurityConstants.FILE_WRITE_ACTION) {
454 return WRITE;
455 } else if (actions == SecurityConstants.FILE_EXECUTE_ACTION) {
456 return EXECUTE;
457 } else if (actions == SecurityConstants.FILE_DELETE_ACTION) {
458 return DELETE;
459 } else if (actions == SecurityConstants.FILE_READLINK_ACTION) {
460 return READLINK;
461 }
462
463 char[] a = actions.toCharArray();
464
465 int i = a.length - 1;
466 if (i < 0)
467 return mask;
468
469 while (i != -1) {
470 char c;
471
472 // skip whitespace
473 while ((i!=-1) && ((c = a[i]) == ' ' ||
474 c == '\r' ||
475 c == '\n' ||
476 c == '\f' ||
477 c == '\t'))
478 i--;
479
480 // check for the known strings
481 int matchlen;
482
483 if (i >= 3 && (a[i-3] == 'r' || a[i-3] == 'R') &&
484 (a[i-2] == 'e' || a[i-2] == 'E') &&
485 (a[i-1] == 'a' || a[i-1] == 'A') &&
486 (a[i] == 'd' || a[i] == 'D'))
487 {
488 matchlen = 4;
489 mask |= READ;
490
491 } else if (i >= 4 && (a[i-4] == 'w' || a[i-4] == 'W') &&
492 (a[i-3] == 'r' || a[i-3] == 'R') &&
493 (a[i-2] == 'i' || a[i-2] == 'I') &&
494 (a[i-1] == 't' || a[i-1] == 'T') &&
495 (a[i] == 'e' || a[i] == 'E'))
496 {
497 matchlen = 5;
498 mask |= WRITE;
499
500 } else if (i >= 6 && (a[i-6] == 'e' || a[i-6] == 'E') &&
501 (a[i-5] == 'x' || a[i-5] == 'X') &&
502 (a[i-4] == 'e' || a[i-4] == 'E') &&
503 (a[i-3] == 'c' || a[i-3] == 'C') &&
504 (a[i-2] == 'u' || a[i-2] == 'U') &&
505 (a[i-1] == 't' || a[i-1] == 'T') &&
506 (a[i] == 'e' || a[i] == 'E'))
507 {
508 matchlen = 7;
509 mask |= EXECUTE;
510
511 } else if (i >= 5 && (a[i-5] == 'd' || a[i-5] == 'D') &&
512 (a[i-4] == 'e' || a[i-4] == 'E') &&
513 (a[i-3] == 'l' || a[i-3] == 'L') &&
514 (a[i-2] == 'e' || a[i-2] == 'E') &&
515 (a[i-1] == 't' || a[i-1] == 'T') &&
516 (a[i] == 'e' || a[i] == 'E'))
517 {
518 matchlen = 6;
519 mask |= DELETE;
520
521 } else if (i >= 7 && (a[i-7] == 'r' || a[i-7] == 'R') &&
522 (a[i-6] == 'e' || a[i-6] == 'E') &&
523 (a[i-5] == 'a' || a[i-5] == 'A') &&
524 (a[i-4] == 'd' || a[i-4] == 'D') &&
525 (a[i-3] == 'l' || a[i-3] == 'L') &&
526 (a[i-2] == 'i' || a[i-2] == 'I') &&
527 (a[i-1] == 'n' || a[i-1] == 'N') &&
528 (a[i] == 'k' || a[i] == 'K'))
529 {
530 matchlen = 8;
531 mask |= READLINK;
532
533 } else {
534 // parse error
535 throw new IllegalArgumentException(
536 "invalid permission: " + actions);
537 }
538
539 // make sure we didn't just match the tail of a word
540 // like "ackbarfaccept". Also, skip to the comma.
541 boolean seencomma = false;
542 while (i >= matchlen && !seencomma) {
543 switch(a[i-matchlen]) {
544 case ',':
545 seencomma = true;
546 break;
547 case ' ': case '\r': case '\n':
548 case '\f': case '\t':
549 break;
550 default:
551 throw new IllegalArgumentException(
552 "invalid permission: " + actions);
553 }
554 i--;
555 }
556
557 // point i at the location of the comma minus one (or -1).
558 i -= matchlen;
559 }
560
561 return mask;
562 }
563
564 /**
565 * Return the current action mask. Used by the FilePermissionCollection.
566 *
567 * @return the actions mask.
568 */
569 int getMask() {
570 return mask;
571 }
572
573 /**
574 * Return the canonical string representation of the actions.
575 * Always returns present actions in the following order:
576 * read, write, execute, delete, readlink.
577 *
578 * @return the canonical string representation of the actions.
579 */
580 private static String getActions(int mask) {
581 StringJoiner sj = new StringJoiner(",");
582
583 if ((mask & READ) == READ) {
584 sj.add("read");
585 }
586 if ((mask & WRITE) == WRITE) {
587 sj.add("write");
588 }
589 if ((mask & EXECUTE) == EXECUTE) {
590 sj.add("execute");
591 }
592 if ((mask & DELETE) == DELETE) {
593 sj.add("delete");
594 }
595 if ((mask & READLINK) == READLINK) {
596 sj.add("readlink");
597 }
598
599 return sj.toString();
600 }
601
602 /**
603 * Returns the "canonical string representation" of the actions.
604 * That is, this method always returns present actions in the following order:
605 * read, write, execute, delete, readlink. For example, if this FilePermission
606 * object allows both write and read actions, a call to <code>getActions</code>
607 * will return the string "read,write".
608 *
609 * @return the canonical string representation of the actions.
610 */
611 public String getActions() {
612 if (actions == null)
613 actions = getActions(this.mask);
614
615 return actions;
616 }
617
618 /**
619 * Returns a new PermissionCollection object for storing FilePermission
620 * objects.
621 * <p>
622 * FilePermission objects must be stored in a manner that allows them
623 * to be inserted into the collection in any order, but that also enables the
624 * PermissionCollection <code>implies</code>
625 * method to be implemented in an efficient (and consistent) manner.
626 *
627 * <p>For example, if you have two FilePermissions:
628 * <OL>
629 * <LI> <code>"/tmp/-", "read"</code>
630 * <LI> <code>"/tmp/scratch/foo", "write"</code>
631 * </OL>
632 *
633 * <p>and you are calling the <code>implies</code> method with the FilePermission:
634 *
635 * <pre>
636 * "/tmp/scratch/foo", "read,write",
637 * </pre>
638 *
639 * then the <code>implies</code> function must
640 * take into account both the "/tmp/-" and "/tmp/scratch/foo"
641 * permissions, so the effective permission is "read,write",
642 * and <code>implies</code> returns true. The "implies" semantics for
643 * FilePermissions are handled properly by the PermissionCollection object
644 * returned by this <code>newPermissionCollection</code> method.
645 *
646 * @return a new PermissionCollection object suitable for storing
647 * FilePermissions.
648 */
649 public PermissionCollection newPermissionCollection() {
650 return new FilePermissionCollection();
651 }
652
653 /**
654 * WriteObject is called to save the state of the FilePermission
655 * to a stream. The actions are serialized, and the superclass
656 * takes care of the name.
657 */
658 private void writeObject(ObjectOutputStream s)
659 throws IOException
660 {
661 // Write out the actions. The superclass takes care of the name
662 // call getActions to make sure actions field is initialized
663 if (actions == null)
664 getActions();
665 s.defaultWriteObject();
666 }
667
668 /**
669 * readObject is called to restore the state of the FilePermission from
670 * a stream.
671 */
672 private void readObject(ObjectInputStream s)
673 throws IOException, ClassNotFoundException
674 {
675 // Read in the actions, then restore everything else by calling init.
676 s.defaultReadObject();
677 init(getMask(actions));
678 }
679 }
680
681 /**
682 * A FilePermissionCollection stores a set of FilePermission permissions.
683 * FilePermission objects
684 * must be stored in a manner that allows them to be inserted in any
685 * order, but enable the implies function to evaluate the implies
686 * method.
687 * For example, if you have two FilePermissions:
688 * <OL>
689 * <LI> "/tmp/-", "read"
690 * <LI> "/tmp/scratch/foo", "write"
691 * </OL>
692 * And you are calling the implies function with the FilePermission:
693 * "/tmp/scratch/foo", "read,write", then the implies function must
694 * take into account both the /tmp/- and /tmp/scratch/foo
695 * permissions, so the effective permission is "read,write".
696 *
697 * @see java.security.Permission
698 * @see java.security.Permissions
699 * @see java.security.PermissionCollection
700 *
701 *
702 * @author Marianne Mueller
703 * @author Roland Schemers
704 *
705 * @serial include
706 *
707 */
708
709 final class FilePermissionCollection extends PermissionCollection
710 implements Serializable
711 {
712 // Not serialized; see serialization section at end of class
713 private transient List<Permission> perms;
714
715 /**
716 * Create an empty FilePermissionCollection object.
717 */
718 public FilePermissionCollection() {
719 perms = new ArrayList<>();
720 }
721
722 /**
723 * Adds a permission to the FilePermissionCollection. The key for the hash is
724 * permission.path.
725 *
726 * @param permission the Permission object to add.
727 *
728 * @exception IllegalArgumentException - if the permission is not a
729 * FilePermission
730 *
731 * @exception SecurityException - if this FilePermissionCollection object
732 * has been marked readonly
733 */
734 public void add(Permission permission) {
735 if (! (permission instanceof FilePermission))
736 throw new IllegalArgumentException("invalid permission: "+
737 permission);
738 if (isReadOnly())
739 throw new SecurityException(
740 "attempt to add a Permission to a readonly PermissionCollection");
741
742 synchronized (this) {
743 perms.add(permission);
744 }
745 }
746
747 /**
748 * Check and see if this set of permissions implies the permissions
749 * expressed in "permission".
750 *
751 * @param permission the Permission object to compare
752 *
753 * @return true if "permission" is a proper subset of a permission in
754 * the set, false if not.
755 */
756 public boolean implies(Permission permission) {
757 if (! (permission instanceof FilePermission))
758 return false;
759
760 FilePermission fp = (FilePermission) permission;
761
762 int desired = fp.getMask();
763 int effective = 0;
764 int needed = desired;
765
766 synchronized (this) {
767 int len = perms.size();
768 for (int i = 0; i < len; i++) {
769 FilePermission x = (FilePermission) perms.get(i);
770 if (((needed & x.getMask()) != 0) && x.impliesIgnoreMask(fp)) {
771 effective |= x.getMask();
772 if ((effective & desired) == desired)
773 return true;
774 needed = (desired ^ effective);
775 }
776 }
777 }
778 return false;
779 }
780
781 /**
782 * Returns an enumeration of all the FilePermission objects in the
783 * container.
784 *
785 * @return an enumeration of all the FilePermission objects.
786 */
787 public Enumeration<Permission> elements() {
788 // Convert Iterator into Enumeration
789 synchronized (this) {
790 return Collections.enumeration(perms);
791 }
792 }
793
794 private static final long serialVersionUID = 2202956749081564585L;
795
796 // Need to maintain serialization interoperability with earlier releases,
797 // which had the serializable field:
798 // private Vector permissions;
799
800 /**
801 * @serialField permissions java.util.Vector
802 * A list of FilePermission objects.
803 */
804 private static final ObjectStreamField[] serialPersistentFields = {
805 new ObjectStreamField("permissions", Vector.class),
806 };
807
808 /**
809 * @serialData "permissions" field (a Vector containing the FilePermissions).
810 */
811 /*
812 * Writes the contents of the perms field out as a Vector for
813 * serialization compatibility with earlier releases.
814 */
815 private void writeObject(ObjectOutputStream out) throws IOException {
816 // Don't call out.defaultWriteObject()
817
818 // Write out Vector
819 Vector<Permission> permissions = new Vector<>(perms.size());
820 synchronized (this) {
821 permissions.addAll(perms);
822 }
823
824 ObjectOutputStream.PutField pfields = out.putFields();
825 pfields.put("permissions", permissions);
826 out.writeFields();
827 }
828
829 /*
830 * Reads in a Vector of FilePermissions and saves them in the perms field.
831 */
832 private void readObject(ObjectInputStream in)
833 throws IOException, ClassNotFoundException
834 {
835 // Don't call defaultReadObject()
836
837 // Read in serialized fields
838 ObjectInputStream.GetField gfields = in.readFields();
839
840 // Get the one we want
841 @SuppressWarnings("unchecked")
842 Vector<Permission> permissions = (Vector<Permission>)gfields.get("permissions", null);
843 perms = new ArrayList<>(permissions.size());
844 perms.addAll(permissions);
845 }
846 }