J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 1997-2005 Sun Microsystems, Inc. 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. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any 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.StringTokenizer; |
| 33 | import java.util.Vector; |
| 34 | import java.util.Collections; |
| 35 | import java.io.ObjectStreamField; |
| 36 | import java.io.ObjectOutputStream; |
| 37 | import java.io.ObjectInputStream; |
| 38 | import java.io.IOException; |
| 39 | import sun.security.util.SecurityConstants; |
| 40 | |
| 41 | /** |
| 42 | * This class represents access to a file or directory. A FilePermission consists |
| 43 | * of a pathname and a set of actions valid for that pathname. |
| 44 | * <P> |
| 45 | * Pathname is the pathname of the file or directory granted the specified |
| 46 | * actions. A pathname that ends in "/*" (where "/" is |
| 47 | * the file separator character, <code>File.separatorChar</code>) indicates |
| 48 | * all the files and directories contained in that directory. A pathname |
| 49 | * that ends with "/-" indicates (recursively) all files |
| 50 | * and subdirectories contained in that directory. A pathname consisting of |
| 51 | * the special token "<<ALL FILES>>" matches <b>any</b> file. |
| 52 | * <P> |
| 53 | * Note: A pathname consisting of a single "*" indicates all the files |
| 54 | * in the current directory, while a pathname consisting of a single "-" |
| 55 | * indicates all the files in the current directory and |
| 56 | * (recursively) all files and subdirectories contained in the current |
| 57 | * directory. |
| 58 | * <P> |
| 59 | * The actions to be granted are passed to the constructor in a string containing |
| 60 | * a list of one or more comma-separated keywords. The possible keywords are |
| 61 | * "read", "write", "execute", and "delete". Their meaning is defined as follows: |
| 62 | * <P> |
| 63 | * <DL> |
| 64 | * <DT> read <DD> read permission |
| 65 | * <DT> write <DD> write permission |
| 66 | * <DT> execute |
| 67 | * <DD> execute permission. Allows <code>Runtime.exec</code> to |
| 68 | * be called. Corresponds to <code>SecurityManager.checkExec</code>. |
| 69 | * <DT> delete |
| 70 | * <DD> delete permission. Allows <code>File.delete</code> to |
| 71 | * be called. Corresponds to <code>SecurityManager.checkDelete</code>. |
| 72 | * </DL> |
| 73 | * <P> |
| 74 | * The actions string is converted to lowercase before processing. |
| 75 | * <P> |
| 76 | * Be careful when granting FilePermissions. Think about the implications |
| 77 | * of granting read and especially write access to various files and |
| 78 | * directories. The "<<ALL FILES>>" permission with write action is |
| 79 | * especially dangerous. This grants permission to write to the entire |
| 80 | * file system. One thing this effectively allows is replacement of the |
| 81 | * system binary, including the JVM runtime environment. |
| 82 | * |
| 83 | * <p>Please note: Code can always read a file from the same |
| 84 | * directory it's in (or a subdirectory of that directory); it does not |
| 85 | * need explicit permission to do so. |
| 86 | * |
| 87 | * @see java.security.Permission |
| 88 | * @see java.security.Permissions |
| 89 | * @see java.security.PermissionCollection |
| 90 | * |
| 91 | * |
| 92 | * @author Marianne Mueller |
| 93 | * @author Roland Schemers |
| 94 | * @since 1.2 |
| 95 | * |
| 96 | * @serial exclude |
| 97 | */ |
| 98 | |
| 99 | public final class FilePermission extends Permission implements Serializable { |
| 100 | |
| 101 | /** |
| 102 | * Execute action. |
| 103 | */ |
| 104 | private final static int EXECUTE = 0x1; |
| 105 | /** |
| 106 | * Write action. |
| 107 | */ |
| 108 | private final static int WRITE = 0x2; |
| 109 | /** |
| 110 | * Read action. |
| 111 | */ |
| 112 | private final static int READ = 0x4; |
| 113 | /** |
| 114 | * Delete action. |
| 115 | */ |
| 116 | private final static int DELETE = 0x8; |
| 117 | |
| 118 | /** |
| 119 | * All actions (read,write,execute,delete) |
| 120 | */ |
| 121 | private final static int ALL = READ|WRITE|EXECUTE|DELETE; |
| 122 | /** |
| 123 | * No actions. |
| 124 | */ |
| 125 | private final static int NONE = 0x0; |
| 126 | |
| 127 | // the actions mask |
| 128 | private transient int mask; |
| 129 | |
| 130 | // does path indicate a directory? (wildcard or recursive) |
| 131 | private transient boolean directory; |
| 132 | |
| 133 | // is it a recursive directory specification? |
| 134 | private transient boolean recursive; |
| 135 | |
| 136 | /** |
| 137 | * the actions string. |
| 138 | * |
| 139 | * @serial |
| 140 | */ |
| 141 | private String actions; // Left null as long as possible, then |
| 142 | // created and re-used in the getAction function. |
| 143 | |
| 144 | // canonicalized dir path. In the case of |
| 145 | // directories, it is the name "/blah/*" or "/blah/-" without |
| 146 | // the last character (the "*" or "-"). |
| 147 | |
| 148 | private transient String cpath; |
| 149 | |
| 150 | // static Strings used by init(int mask) |
| 151 | private static final char RECURSIVE_CHAR = '-'; |
| 152 | private static final char WILD_CHAR = '*'; |
| 153 | |
| 154 | /* |
| 155 | public String toString() |
| 156 | { |
| 157 | StringBuffer sb = new StringBuffer(); |
| 158 | sb.append("***\n"); |
| 159 | sb.append("cpath = "+cpath+"\n"); |
| 160 | sb.append("mask = "+mask+"\n"); |
| 161 | sb.append("actions = "+getActions()+"\n"); |
| 162 | sb.append("directory = "+directory+"\n"); |
| 163 | sb.append("recursive = "+recursive+"\n"); |
| 164 | sb.append("***\n"); |
| 165 | return sb.toString(); |
| 166 | } |
| 167 | */ |
| 168 | |
| 169 | private static final long serialVersionUID = 7930732926638008763L; |
| 170 | |
| 171 | /** |
| 172 | * initialize a FilePermission object. Common to all constructors. |
| 173 | * Also called during de-serialization. |
| 174 | * |
| 175 | * @param mask the actions mask to use. |
| 176 | * |
| 177 | */ |
| 178 | private void init(int mask) |
| 179 | { |
| 180 | |
| 181 | if ((mask & ALL) != mask) |
| 182 | throw new IllegalArgumentException("invalid actions mask"); |
| 183 | |
| 184 | if (mask == NONE) |
| 185 | throw new IllegalArgumentException("invalid actions mask"); |
| 186 | |
| 187 | if ((cpath = getName()) == null) |
| 188 | throw new NullPointerException("name can't be null"); |
| 189 | |
| 190 | this.mask = mask; |
| 191 | |
| 192 | if (cpath.equals("<<ALL FILES>>")) { |
| 193 | directory = true; |
| 194 | recursive = true; |
| 195 | cpath = ""; |
| 196 | return; |
| 197 | } |
| 198 | |
| 199 | // store only the canonical cpath if possible |
| 200 | cpath = AccessController.doPrivileged(new PrivilegedAction<String>() { |
| 201 | public String run() { |
| 202 | try { |
| 203 | return sun.security.provider.PolicyFile.canonPath(cpath); |
| 204 | } catch (IOException ioe) { |
| 205 | return cpath; |
| 206 | } |
| 207 | } |
| 208 | }); |
| 209 | |
| 210 | int len = cpath.length(); |
| 211 | char last = ((len > 0) ? cpath.charAt(len - 1) : 0); |
| 212 | |
| 213 | if (last == RECURSIVE_CHAR && |
| 214 | cpath.charAt(len - 2) == File.separatorChar) { |
| 215 | directory = true; |
| 216 | recursive = true; |
| 217 | cpath = cpath.substring(0, --len); |
| 218 | } else if (last == WILD_CHAR && |
| 219 | cpath.charAt(len - 2) == File.separatorChar) { |
| 220 | directory = true; |
| 221 | //recursive = false; |
| 222 | cpath = cpath.substring(0, --len); |
| 223 | } else { |
| 224 | // overkill since they are initialized to false, but |
| 225 | // commented out here to remind us... |
| 226 | //directory = false; |
| 227 | //recursive = false; |
| 228 | } |
| 229 | |
| 230 | // XXX: at this point the path should be absolute. die if it isn't? |
| 231 | } |
| 232 | |
| 233 | /** |
| 234 | * Creates a new FilePermission object with the specified actions. |
| 235 | * <i>path</i> is the pathname of a file or directory, and <i>actions</i> |
| 236 | * contains a comma-separated list of the desired actions granted on the |
| 237 | * file or directory. Possible actions are |
| 238 | * "read", "write", "execute", and "delete". |
| 239 | * |
| 240 | * <p>A pathname that ends in "/*" (where "/" is |
| 241 | * the file separator character, <code>File.separatorChar</code>) |
| 242 | * indicates all the files and directories contained in that directory. |
| 243 | * A pathname that ends with "/-" indicates (recursively) all files and |
| 244 | * subdirectories contained in that directory. The special pathname |
| 245 | * "<<ALL FILES>>" matches any file. |
| 246 | * |
| 247 | * <p>A pathname consisting of a single "*" indicates all the files |
| 248 | * in the current directory, while a pathname consisting of a single "-" |
| 249 | * indicates all the files in the current directory and |
| 250 | * (recursively) all files and subdirectories contained in the current |
| 251 | * directory. |
| 252 | * |
| 253 | * <p>A pathname containing an empty string represents an empty path. |
| 254 | * |
| 255 | * @param path the pathname of the file/directory. |
| 256 | * @param actions the action string. |
| 257 | * |
| 258 | * @throws IllegalArgumentException |
| 259 | * If actions is <code>null</code>, empty or contains an action |
| 260 | * other than the specified possible actions. |
| 261 | */ |
| 262 | |
| 263 | public FilePermission(String path, String actions) |
| 264 | { |
| 265 | super(path); |
| 266 | init(getMask(actions)); |
| 267 | } |
| 268 | |
| 269 | /** |
| 270 | * Creates a new FilePermission object using an action mask. |
| 271 | * More efficient than the FilePermission(String, String) constructor. |
| 272 | * Can be used from within |
| 273 | * code that needs to create a FilePermission object to pass into the |
| 274 | * <code>implies</code> method. |
| 275 | * |
| 276 | * @param path the pathname of the file/directory. |
| 277 | * @param mask the action mask to use. |
| 278 | */ |
| 279 | |
| 280 | // package private for use by the FilePermissionCollection add method |
| 281 | FilePermission(String path, int mask) |
| 282 | { |
| 283 | super(path); |
| 284 | init(mask); |
| 285 | } |
| 286 | |
| 287 | /** |
| 288 | * Checks if this FilePermission object "implies" the specified permission. |
| 289 | * <P> |
| 290 | * More specifically, this method returns true if:<p> |
| 291 | * <ul> |
| 292 | * <li> <i>p</i> is an instanceof FilePermission,<p> |
| 293 | * <li> <i>p</i>'s actions are a proper subset of this |
| 294 | * object's actions, and <p> |
| 295 | * <li> <i>p</i>'s pathname is implied by this object's |
| 296 | * pathname. For example, "/tmp/*" implies "/tmp/foo", since |
| 297 | * "/tmp/*" encompasses all files in the "/tmp" directory, |
| 298 | * including the one named "foo". |
| 299 | * </ul> |
| 300 | * |
| 301 | * @param p the permission to check against. |
| 302 | * |
| 303 | * @return <code>true</code> if the specified permission is not |
| 304 | * <code>null</code> and is implied by this object, |
| 305 | * <code>false</code> otherwise. |
| 306 | */ |
| 307 | public boolean implies(Permission p) { |
| 308 | if (!(p instanceof FilePermission)) |
| 309 | return false; |
| 310 | |
| 311 | FilePermission that = (FilePermission) p; |
| 312 | |
| 313 | // we get the effective mask. i.e., the "and" of this and that. |
| 314 | // They must be equal to that.mask for implies to return true. |
| 315 | |
| 316 | return ((this.mask & that.mask) == that.mask) && impliesIgnoreMask(that); |
| 317 | } |
| 318 | |
| 319 | /** |
| 320 | * Checks if the Permission's actions are a proper subset of the |
| 321 | * this object's actions. Returns the effective mask iff the |
| 322 | * this FilePermission's path also implies that FilePermission's path. |
| 323 | * |
| 324 | * @param that the FilePermission to check against. |
| 325 | * @param exact return immediately if the masks are not equal |
| 326 | * @return the effective mask |
| 327 | */ |
| 328 | boolean impliesIgnoreMask(FilePermission that) { |
| 329 | if (this.directory) { |
| 330 | if (this.recursive) { |
| 331 | // make sure that.path is longer then path so |
| 332 | // something like /foo/- does not imply /foo |
| 333 | if (that.directory) { |
| 334 | return (that.cpath.length() >= this.cpath.length()) && |
| 335 | that.cpath.startsWith(this.cpath); |
| 336 | } else { |
| 337 | return ((that.cpath.length() > this.cpath.length()) && |
| 338 | that.cpath.startsWith(this.cpath)); |
| 339 | } |
| 340 | } else { |
| 341 | if (that.directory) { |
| 342 | // if the permission passed in is a directory |
| 343 | // specification, make sure that a non-recursive |
| 344 | // permission (i.e., this object) can't imply a recursive |
| 345 | // permission. |
| 346 | if (that.recursive) |
| 347 | return false; |
| 348 | else |
| 349 | return (this.cpath.equals(that.cpath)); |
| 350 | } else { |
| 351 | int last = that.cpath.lastIndexOf(File.separatorChar); |
| 352 | if (last == -1) |
| 353 | return false; |
| 354 | else { |
| 355 | // this.cpath.equals(that.cpath.substring(0, last+1)); |
| 356 | // Use regionMatches to avoid creating new string |
| 357 | return (this.cpath.length() == (last + 1)) && |
| 358 | this.cpath.regionMatches(0, that.cpath, 0, last+1); |
| 359 | } |
| 360 | } |
| 361 | } |
| 362 | } else if (that.directory) { |
| 363 | // if this is NOT recursive/wildcarded, |
| 364 | // do not let it imply a recursive/wildcarded permission |
| 365 | return false; |
| 366 | } else { |
| 367 | return (this.cpath.equals(that.cpath)); |
| 368 | } |
| 369 | } |
| 370 | |
| 371 | /** |
| 372 | * Checks two FilePermission objects for equality. Checks that <i>obj</i> is |
| 373 | * a FilePermission, and has the same pathname and actions as this object. |
| 374 | * <P> |
| 375 | * @param obj the object we are testing for equality with this object. |
| 376 | * @return <code>true</code> if obj is a FilePermission, and has the same |
| 377 | * pathname and actions as this FilePermission object, |
| 378 | * <code>false</code> otherwise. |
| 379 | */ |
| 380 | public boolean equals(Object obj) { |
| 381 | if (obj == this) |
| 382 | return true; |
| 383 | |
| 384 | if (! (obj instanceof FilePermission)) |
| 385 | return false; |
| 386 | |
| 387 | FilePermission that = (FilePermission) obj; |
| 388 | |
| 389 | return (this.mask == that.mask) && |
| 390 | this.cpath.equals(that.cpath) && |
| 391 | (this.directory == that.directory) && |
| 392 | (this.recursive == that.recursive); |
| 393 | } |
| 394 | |
| 395 | /** |
| 396 | * Returns the hash code value for this object. |
| 397 | * |
| 398 | * @return a hash code value for this object. |
| 399 | */ |
| 400 | |
| 401 | public int hashCode() { |
| 402 | return this.cpath.hashCode(); |
| 403 | } |
| 404 | |
| 405 | /** |
| 406 | * Converts an actions String to an actions mask. |
| 407 | * |
| 408 | * @param action the action string. |
| 409 | * @return the actions mask. |
| 410 | */ |
| 411 | private static int getMask(String actions) { |
| 412 | |
| 413 | int mask = NONE; |
| 414 | |
| 415 | // Null action valid? |
| 416 | if (actions == null) { |
| 417 | return mask; |
| 418 | } |
| 419 | // Check against use of constants (used heavily within the JDK) |
| 420 | if (actions == SecurityConstants.FILE_READ_ACTION) { |
| 421 | return READ; |
| 422 | } else if (actions == SecurityConstants.FILE_WRITE_ACTION) { |
| 423 | return WRITE; |
| 424 | } else if (actions == SecurityConstants.FILE_EXECUTE_ACTION) { |
| 425 | return EXECUTE; |
| 426 | } else if (actions == SecurityConstants.FILE_DELETE_ACTION) { |
| 427 | return DELETE; |
| 428 | } |
| 429 | |
| 430 | char[] a = actions.toCharArray(); |
| 431 | |
| 432 | int i = a.length - 1; |
| 433 | if (i < 0) |
| 434 | return mask; |
| 435 | |
| 436 | while (i != -1) { |
| 437 | char c; |
| 438 | |
| 439 | // skip whitespace |
| 440 | while ((i!=-1) && ((c = a[i]) == ' ' || |
| 441 | c == '\r' || |
| 442 | c == '\n' || |
| 443 | c == '\f' || |
| 444 | c == '\t')) |
| 445 | i--; |
| 446 | |
| 447 | // check for the known strings |
| 448 | int matchlen; |
| 449 | |
| 450 | if (i >= 3 && (a[i-3] == 'r' || a[i-3] == 'R') && |
| 451 | (a[i-2] == 'e' || a[i-2] == 'E') && |
| 452 | (a[i-1] == 'a' || a[i-1] == 'A') && |
| 453 | (a[i] == 'd' || a[i] == 'D')) |
| 454 | { |
| 455 | matchlen = 4; |
| 456 | mask |= READ; |
| 457 | |
| 458 | } else if (i >= 4 && (a[i-4] == 'w' || a[i-4] == 'W') && |
| 459 | (a[i-3] == 'r' || a[i-3] == 'R') && |
| 460 | (a[i-2] == 'i' || a[i-2] == 'I') && |
| 461 | (a[i-1] == 't' || a[i-1] == 'T') && |
| 462 | (a[i] == 'e' || a[i] == 'E')) |
| 463 | { |
| 464 | matchlen = 5; |
| 465 | mask |= WRITE; |
| 466 | |
| 467 | } else if (i >= 6 && (a[i-6] == 'e' || a[i-6] == 'E') && |
| 468 | (a[i-5] == 'x' || a[i-5] == 'X') && |
| 469 | (a[i-4] == 'e' || a[i-4] == 'E') && |
| 470 | (a[i-3] == 'c' || a[i-3] == 'C') && |
| 471 | (a[i-2] == 'u' || a[i-2] == 'U') && |
| 472 | (a[i-1] == 't' || a[i-1] == 'T') && |
| 473 | (a[i] == 'e' || a[i] == 'E')) |
| 474 | { |
| 475 | matchlen = 7; |
| 476 | mask |= EXECUTE; |
| 477 | |
| 478 | } else if (i >= 5 && (a[i-5] == 'd' || a[i-5] == 'D') && |
| 479 | (a[i-4] == 'e' || a[i-4] == 'E') && |
| 480 | (a[i-3] == 'l' || a[i-3] == 'L') && |
| 481 | (a[i-2] == 'e' || a[i-2] == 'E') && |
| 482 | (a[i-1] == 't' || a[i-1] == 'T') && |
| 483 | (a[i] == 'e' || a[i] == 'E')) |
| 484 | { |
| 485 | matchlen = 6; |
| 486 | mask |= DELETE; |
| 487 | |
| 488 | } else { |
| 489 | // parse error |
| 490 | throw new IllegalArgumentException( |
| 491 | "invalid permission: " + actions); |
| 492 | } |
| 493 | |
| 494 | // make sure we didn't just match the tail of a word |
| 495 | // like "ackbarfaccept". Also, skip to the comma. |
| 496 | boolean seencomma = false; |
| 497 | while (i >= matchlen && !seencomma) { |
| 498 | switch(a[i-matchlen]) { |
| 499 | case ',': |
| 500 | seencomma = true; |
| 501 | /*FALLTHROUGH*/ |
| 502 | case ' ': case '\r': case '\n': |
| 503 | case '\f': case '\t': |
| 504 | break; |
| 505 | default: |
| 506 | throw new IllegalArgumentException( |
| 507 | "invalid permission: " + actions); |
| 508 | } |
| 509 | i--; |
| 510 | } |
| 511 | |
| 512 | // point i at the location of the comma minus one (or -1). |
| 513 | i -= matchlen; |
| 514 | } |
| 515 | |
| 516 | return mask; |
| 517 | } |
| 518 | |
| 519 | /** |
| 520 | * Return the current action mask. Used by the FilePermissionCollection. |
| 521 | * |
| 522 | * @return the actions mask. |
| 523 | */ |
| 524 | |
| 525 | int getMask() { |
| 526 | return mask; |
| 527 | } |
| 528 | |
| 529 | /** |
| 530 | * Return the canonical string representation of the actions. |
| 531 | * Always returns present actions in the following order: |
| 532 | * read, write, execute, delete. |
| 533 | * |
| 534 | * @return the canonical string representation of the actions. |
| 535 | */ |
| 536 | private static String getActions(int mask) |
| 537 | { |
| 538 | StringBuilder sb = new StringBuilder(); |
| 539 | boolean comma = false; |
| 540 | |
| 541 | if ((mask & READ) == READ) { |
| 542 | comma = true; |
| 543 | sb.append("read"); |
| 544 | } |
| 545 | |
| 546 | if ((mask & WRITE) == WRITE) { |
| 547 | if (comma) sb.append(','); |
| 548 | else comma = true; |
| 549 | sb.append("write"); |
| 550 | } |
| 551 | |
| 552 | if ((mask & EXECUTE) == EXECUTE) { |
| 553 | if (comma) sb.append(','); |
| 554 | else comma = true; |
| 555 | sb.append("execute"); |
| 556 | } |
| 557 | |
| 558 | if ((mask & DELETE) == DELETE) { |
| 559 | if (comma) sb.append(','); |
| 560 | else comma = true; |
| 561 | sb.append("delete"); |
| 562 | } |
| 563 | |
| 564 | return sb.toString(); |
| 565 | } |
| 566 | |
| 567 | /** |
| 568 | * Returns the "canonical string representation" of the actions. |
| 569 | * That is, this method always returns present actions in the following order: |
| 570 | * read, write, execute, delete. For example, if this FilePermission object |
| 571 | * allows both write and read actions, a call to <code>getActions</code> |
| 572 | * will return the string "read,write". |
| 573 | * |
| 574 | * @return the canonical string representation of the actions. |
| 575 | */ |
| 576 | public String getActions() |
| 577 | { |
| 578 | if (actions == null) |
| 579 | actions = getActions(this.mask); |
| 580 | |
| 581 | return actions; |
| 582 | } |
| 583 | |
| 584 | |
| 585 | /** |
| 586 | * Returns a new PermissionCollection object for storing FilePermission |
| 587 | * objects. |
| 588 | * <p> |
| 589 | * FilePermission objects must be stored in a manner that allows them |
| 590 | * to be inserted into the collection in any order, but that also enables the |
| 591 | * PermissionCollection <code>implies</code> |
| 592 | * method to be implemented in an efficient (and consistent) manner. |
| 593 | * |
| 594 | * <p>For example, if you have two FilePermissions: |
| 595 | * <OL> |
| 596 | * <LI> <code>"/tmp/-", "read"</code> |
| 597 | * <LI> <code>"/tmp/scratch/foo", "write"</code> |
| 598 | * </OL> |
| 599 | * |
| 600 | * <p>and you are calling the <code>implies</code> method with the FilePermission: |
| 601 | * |
| 602 | * <pre> |
| 603 | * "/tmp/scratch/foo", "read,write", |
| 604 | * </pre> |
| 605 | * |
| 606 | * then the <code>implies</code> function must |
| 607 | * take into account both the "/tmp/-" and "/tmp/scratch/foo" |
| 608 | * permissions, so the effective permission is "read,write", |
| 609 | * and <code>implies</code> returns true. The "implies" semantics for |
| 610 | * FilePermissions are handled properly by the PermissionCollection object |
| 611 | * returned by this <code>newPermissionCollection</code> method. |
| 612 | * |
| 613 | * @return a new PermissionCollection object suitable for storing |
| 614 | * FilePermissions. |
| 615 | */ |
| 616 | |
| 617 | public PermissionCollection newPermissionCollection() { |
| 618 | return new FilePermissionCollection(); |
| 619 | } |
| 620 | |
| 621 | /** |
| 622 | * WriteObject is called to save the state of the FilePermission |
| 623 | * to a stream. The actions are serialized, and the superclass |
| 624 | * takes care of the name. |
| 625 | */ |
| 626 | private void writeObject(ObjectOutputStream s) |
| 627 | throws IOException |
| 628 | { |
| 629 | // Write out the actions. The superclass takes care of the name |
| 630 | // call getActions to make sure actions field is initialized |
| 631 | if (actions == null) |
| 632 | getActions(); |
| 633 | s.defaultWriteObject(); |
| 634 | } |
| 635 | |
| 636 | /** |
| 637 | * readObject is called to restore the state of the FilePermission from |
| 638 | * a stream. |
| 639 | */ |
| 640 | private void readObject(ObjectInputStream s) |
| 641 | throws IOException, ClassNotFoundException |
| 642 | { |
| 643 | // Read in the actions, then restore everything else by calling init. |
| 644 | s.defaultReadObject(); |
| 645 | init(getMask(actions)); |
| 646 | } |
| 647 | } |
| 648 | |
| 649 | /** |
| 650 | * A FilePermissionCollection stores a set of FilePermission permissions. |
| 651 | * FilePermission objects |
| 652 | * must be stored in a manner that allows them to be inserted in any |
| 653 | * order, but enable the implies function to evaluate the implies |
| 654 | * method. |
| 655 | * For example, if you have two FilePermissions: |
| 656 | * <OL> |
| 657 | * <LI> "/tmp/-", "read" |
| 658 | * <LI> "/tmp/scratch/foo", "write" |
| 659 | * </OL> |
| 660 | * And you are calling the implies function with the FilePermission: |
| 661 | * "/tmp/scratch/foo", "read,write", then the implies function must |
| 662 | * take into account both the /tmp/- and /tmp/scratch/foo |
| 663 | * permissions, so the effective permission is "read,write". |
| 664 | * |
| 665 | * @see java.security.Permission |
| 666 | * @see java.security.Permissions |
| 667 | * @see java.security.PermissionCollection |
| 668 | * |
| 669 | * |
| 670 | * @author Marianne Mueller |
| 671 | * @author Roland Schemers |
| 672 | * |
| 673 | * @serial include |
| 674 | * |
| 675 | */ |
| 676 | |
| 677 | final class FilePermissionCollection extends PermissionCollection |
| 678 | implements Serializable { |
| 679 | |
| 680 | // Not serialized; see serialization section at end of class |
| 681 | private transient List perms; |
| 682 | |
| 683 | /** |
| 684 | * Create an empty FilePermissions object. |
| 685 | * |
| 686 | */ |
| 687 | |
| 688 | public FilePermissionCollection() { |
| 689 | perms = new ArrayList(); |
| 690 | } |
| 691 | |
| 692 | /** |
| 693 | * Adds a permission to the FilePermissions. The key for the hash is |
| 694 | * permission.path. |
| 695 | * |
| 696 | * @param permission the Permission object to add. |
| 697 | * |
| 698 | * @exception IllegalArgumentException - if the permission is not a |
| 699 | * FilePermission |
| 700 | * |
| 701 | * @exception SecurityException - if this FilePermissionCollection object |
| 702 | * has been marked readonly |
| 703 | */ |
| 704 | |
| 705 | public void add(Permission permission) |
| 706 | { |
| 707 | if (! (permission instanceof FilePermission)) |
| 708 | throw new IllegalArgumentException("invalid permission: "+ |
| 709 | permission); |
| 710 | if (isReadOnly()) |
| 711 | throw new SecurityException( |
| 712 | "attempt to add a Permission to a readonly PermissionCollection"); |
| 713 | |
| 714 | synchronized (this) { |
| 715 | perms.add(permission); |
| 716 | } |
| 717 | } |
| 718 | |
| 719 | /** |
| 720 | * Check and see if this set of permissions implies the permissions |
| 721 | * expressed in "permission". |
| 722 | * |
| 723 | * @param p the Permission object to compare |
| 724 | * |
| 725 | * @return true if "permission" is a proper subset of a permission in |
| 726 | * the set, false if not. |
| 727 | */ |
| 728 | |
| 729 | public boolean implies(Permission permission) |
| 730 | { |
| 731 | if (! (permission instanceof FilePermission)) |
| 732 | return false; |
| 733 | |
| 734 | FilePermission fp = (FilePermission) permission; |
| 735 | |
| 736 | int desired = fp.getMask(); |
| 737 | int effective = 0; |
| 738 | int needed = desired; |
| 739 | |
| 740 | synchronized (this) { |
| 741 | int len = perms.size(); |
| 742 | for (int i = 0; i < len; i++) { |
| 743 | FilePermission x = (FilePermission) perms.get(i); |
| 744 | if (((needed & x.getMask()) != 0) && x.impliesIgnoreMask(fp)) { |
| 745 | effective |= x.getMask(); |
| 746 | if ((effective & desired) == desired) |
| 747 | return true; |
| 748 | needed = (desired ^ effective); |
| 749 | } |
| 750 | } |
| 751 | } |
| 752 | return false; |
| 753 | } |
| 754 | |
| 755 | /** |
| 756 | * Returns an enumeration of all the FilePermission objects in the |
| 757 | * container. |
| 758 | * |
| 759 | * @return an enumeration of all the FilePermission objects. |
| 760 | */ |
| 761 | |
| 762 | public Enumeration elements() { |
| 763 | // Convert Iterator into Enumeration |
| 764 | synchronized (this) { |
| 765 | return Collections.enumeration(perms); |
| 766 | } |
| 767 | } |
| 768 | |
| 769 | private static final long serialVersionUID = 2202956749081564585L; |
| 770 | |
| 771 | // Need to maintain serialization interoperability with earlier releases, |
| 772 | // which had the serializable field: |
| 773 | // private Vector permissions; |
| 774 | |
| 775 | /** |
| 776 | * @serialField permissions java.util.Vector |
| 777 | * A list of FilePermission objects. |
| 778 | */ |
| 779 | private static final ObjectStreamField[] serialPersistentFields = { |
| 780 | new ObjectStreamField("permissions", Vector.class), |
| 781 | }; |
| 782 | |
| 783 | /** |
| 784 | * @serialData "permissions" field (a Vector containing the FilePermissions). |
| 785 | */ |
| 786 | /* |
| 787 | * Writes the contents of the perms field out as a Vector for |
| 788 | * serialization compatibility with earlier releases. |
| 789 | */ |
| 790 | private void writeObject(ObjectOutputStream out) throws IOException { |
| 791 | // Don't call out.defaultWriteObject() |
| 792 | |
| 793 | // Write out Vector |
| 794 | Vector permissions = new Vector(perms.size()); |
| 795 | synchronized (this) { |
| 796 | permissions.addAll(perms); |
| 797 | } |
| 798 | |
| 799 | ObjectOutputStream.PutField pfields = out.putFields(); |
| 800 | pfields.put("permissions", permissions); |
| 801 | out.writeFields(); |
| 802 | } |
| 803 | |
| 804 | /* |
| 805 | * Reads in a Vector of FilePermissions and saves them in the perms field. |
| 806 | */ |
| 807 | private void readObject(ObjectInputStream in) throws IOException, |
| 808 | ClassNotFoundException { |
| 809 | // Don't call defaultReadObject() |
| 810 | |
| 811 | // Read in serialized fields |
| 812 | ObjectInputStream.GetField gfields = in.readFields(); |
| 813 | |
| 814 | // Get the one we want |
| 815 | Vector permissions = (Vector)gfields.get("permissions", null); |
| 816 | perms = new ArrayList(permissions.size()); |
| 817 | perms.addAll(permissions); |
| 818 | } |
| 819 | } |