001/* 002 * Licensed to the Apache Software Foundation (ASF) under one 003 * or more contributor license agreements. See the NOTICE file 004 * distributed with this work for additional information 005 * regarding copyright ownership. The ASF licenses this file 006 * to you under the Apache License, Version 2.0 (the 007 * "License"); you may not use this file except in compliance 008 * with the License. You may obtain a copy of the License at 009 * 010 * http://www.apache.org/licenses/LICENSE-2.0 011 * 012 * Unless required by applicable law or agreed to in writing, 013 * software distributed under the License is distributed on an 014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 015 * KIND, either express or implied. See the License for the 016 * specific language governing permissions and limitations 017 * under the License. 018 */ 019package org.apache.commons.compress.archivers.zip; 020 021import java.io.Serializable; 022import java.util.Date; 023import java.util.zip.ZipException; 024 025/** 026 * <p>An extra field that stores additional file and directory timestamp data 027 * for zip entries. Each zip entry can include up to three timestamps 028 * (modify, access, create*). The timestamps are stored as 32 bit unsigned 029 * integers representing seconds since UNIX epoch (Jan 1st, 1970, UTC). 030 * This field improves on zip's default timestamp granularity, since it 031 * allows one to store additional timestamps, and, in addition, the timestamps 032 * are stored using per-second granularity (zip's default behaviour can only store 033 * timestamps to the nearest <em>even</em> second). 034 * </p><p> 035 * Unfortunately, 32 (unsigned) bits can only store dates up to the year 2106, 036 * and so this extra field will eventually be obsolete. Enjoy it while it lasts! 037 * </p> 038 * <ul> 039 * <li><b>modifyTime:</b> 040 * most recent time of file/directory modification 041 * (or file/dir creation if the entry has not been 042 * modified since it was created). 043 * </li> 044 * <li><b>accessTime:</b> 045 * most recent time file/directory was opened 046 * (e.g., read from disk). Many people disable 047 * their operating systems from updating this value 048 * using the NOATIME mount option to optimize disk behaviour, 049 * and thus it's not always reliable. In those cases 050 * it's always equal to modifyTime. 051 * </li> 052 * <li><b>*createTime:</b> 053 * modern linux file systems (e.g., ext2 and newer) 054 * do not appear to store a value like this, and so 055 * it's usually omitted altogether in the zip extra 056 * field. Perhaps other unix systems track this. 057 * </li></ul> 058 * <p> 059 * We're using the field definition given in Info-Zip's source archive: 060 * zip-3.0.tar.gz/proginfo/extrafld.txt 061 * </p> 062 * <pre> 063 * Value Size Description 064 * ----- ---- ----------- 065 * 0x5455 Short tag for this extra block type ("UT") 066 * TSize Short total data size for this block 067 * Flags Byte info bits 068 * (ModTime) Long time of last modification (UTC/GMT) 069 * (AcTime) Long time of last access (UTC/GMT) 070 * (CrTime) Long time of original creation (UTC/GMT) 071 * 072 * Central-header version: 073 * 074 * Value Size Description 075 * ----- ---- ----------- 076 * 0x5455 Short tag for this extra block type ("UT") 077 * TSize Short total data size for this block 078 * Flags Byte info bits (refers to local header!) 079 * (ModTime) Long time of last modification (UTC/GMT) 080 * </pre> 081 * @since 1.5 082 */ 083public class X5455_ExtendedTimestamp implements ZipExtraField, Cloneable, Serializable { 084 private static final ZipShort HEADER_ID = new ZipShort(0x5455); 085 private static final long serialVersionUID = 1L; 086 087 /** 088 * The bit set inside the flags by when the last modification time 089 * is present in this extra field. 090 */ 091 public static final byte MODIFY_TIME_BIT = 1; 092 /** 093 * The bit set inside the flags by when the lasr access time is 094 * present in this extra field. 095 */ 096 public static final byte ACCESS_TIME_BIT = 2; 097 /** 098 * The bit set inside the flags by when the original creation time 099 * is present in this extra field. 100 */ 101 public static final byte CREATE_TIME_BIT = 4; 102 103 // The 3 boolean fields (below) come from this flags byte. The remaining 5 bits 104 // are ignored according to the current version of the spec (December 2012). 105 private byte flags; 106 107 // Note: even if bit1 and bit2 are set, the Central data will still not contain 108 // access/create fields: only local data ever holds those! This causes 109 // some of our implementation to look a little odd, with seemingly spurious 110 // != null and length checks. 111 private boolean bit0_modifyTimePresent; 112 private boolean bit1_accessTimePresent; 113 private boolean bit2_createTimePresent; 114 115 private ZipLong modifyTime; 116 private ZipLong accessTime; 117 private ZipLong createTime; 118 119 /** 120 * Constructor for X5455_ExtendedTimestamp. 121 */ 122 public X5455_ExtendedTimestamp() {} 123 124 /** 125 * The Header-ID. 126 * 127 * @return the value for the header id for this extrafield 128 */ 129 public ZipShort getHeaderId() { 130 return HEADER_ID; 131 } 132 133 /** 134 * Length of the extra field in the local file data - without 135 * Header-ID or length specifier. 136 * 137 * @return a <code>ZipShort</code> for the length of the data of this extra field 138 */ 139 public ZipShort getLocalFileDataLength() { 140 return new ZipShort(1 + 141 (bit0_modifyTimePresent ? 4 : 0) + 142 (bit1_accessTimePresent && accessTime != null ? 4 : 0) + 143 (bit2_createTimePresent && createTime != null ? 4 : 0) 144 ); 145 } 146 147 /** 148 * Length of the extra field in the local file data - without 149 * Header-ID or length specifier. 150 * 151 * <p>For X5455 the central length is often smaller than the 152 * local length, because central cannot contain access or create 153 * timestamps.</p> 154 * 155 * @return a <code>ZipShort</code> for the length of the data of this extra field 156 */ 157 public ZipShort getCentralDirectoryLength() { 158 return new ZipShort(1 + 159 (bit0_modifyTimePresent ? 4 : 0) 160 ); 161 } 162 163 /** 164 * The actual data to put into local file data - without Header-ID 165 * or length specifier. 166 * 167 * @return get the data 168 */ 169 public byte[] getLocalFileDataData() { 170 byte[] data = new byte[getLocalFileDataLength().getValue()]; 171 int pos = 0; 172 data[pos++] = 0; 173 if (bit0_modifyTimePresent) { 174 data[0] |= MODIFY_TIME_BIT; 175 System.arraycopy(modifyTime.getBytes(), 0, data, pos, 4); 176 pos += 4; 177 } 178 if (bit1_accessTimePresent && accessTime != null) { 179 data[0] |= ACCESS_TIME_BIT; 180 System.arraycopy(accessTime.getBytes(), 0, data, pos, 4); 181 pos += 4; 182 } 183 if (bit2_createTimePresent && createTime != null) { 184 data[0] |= CREATE_TIME_BIT; 185 System.arraycopy(createTime.getBytes(), 0, data, pos, 4); 186 pos += 4; 187 } 188 return data; 189 } 190 191 /** 192 * The actual data to put into central directory data - without Header-ID 193 * or length specifier. 194 * 195 * @return the central directory data 196 */ 197 public byte[] getCentralDirectoryData() { 198 byte[] centralData = new byte[getCentralDirectoryLength().getValue()]; 199 byte[] localData = getLocalFileDataData(); 200 201 // Truncate out create & access time (last 8 bytes) from 202 // the copy of the local data we obtained: 203 System.arraycopy(localData, 0, centralData, 0, centralData.length); 204 return centralData; 205 } 206 207 /** 208 * Populate data from this array as if it was in local file data. 209 * 210 * @param data an array of bytes 211 * @param offset the start offset 212 * @param length the number of bytes in the array from offset 213 * @throws java.util.zip.ZipException on error 214 */ 215 public void parseFromLocalFileData( 216 byte[] data, int offset, int length 217 ) throws ZipException { 218 reset(); 219 final int len = offset + length; 220 setFlags(data[offset++]); 221 if (bit0_modifyTimePresent) { 222 modifyTime = new ZipLong(data, offset); 223 offset += 4; 224 } 225 226 // Notice the extra length check in case we are parsing the shorter 227 // central data field (for both access and create timestamps). 228 if (bit1_accessTimePresent && offset + 4 <= len) { 229 accessTime = new ZipLong(data, offset); 230 offset += 4; 231 } 232 if (bit2_createTimePresent && offset + 4 <= len) { 233 createTime = new ZipLong(data, offset); 234 offset += 4; 235 } 236 } 237 238 /** 239 * Doesn't do anything special since this class always uses the 240 * same parsing logic for both central directory and local file data. 241 */ 242 public void parseFromCentralDirectoryData( 243 byte[] buffer, int offset, int length 244 ) throws ZipException { 245 reset(); 246 parseFromLocalFileData(buffer, offset, length); 247 } 248 249 /** 250 * Reset state back to newly constructed state. Helps us make sure 251 * parse() calls always generate clean results. 252 */ 253 private void reset() { 254 setFlags((byte) 0); 255 this.modifyTime = null; 256 this.accessTime = null; 257 this.createTime = null; 258 } 259 260 /** 261 * Sets flags byte. The flags byte tells us which of the 262 * three datestamp fields are present in the data: 263 * <pre> 264 * bit0 - modify time 265 * bit1 - access time 266 * bit2 - create time 267 * </pre> 268 * Only first 3 bits of flags are used according to the 269 * latest version of the spec (December 2012). 270 * 271 * @param flags flags byte indicating which of the 272 * three datestamp fields are present. 273 */ 274 public void setFlags(byte flags) { 275 this.flags = flags; 276 this.bit0_modifyTimePresent = (flags & MODIFY_TIME_BIT) == MODIFY_TIME_BIT; 277 this.bit1_accessTimePresent = (flags & ACCESS_TIME_BIT) == ACCESS_TIME_BIT; 278 this.bit2_createTimePresent = (flags & CREATE_TIME_BIT) == CREATE_TIME_BIT; 279 } 280 281 /** 282 * Gets flags byte. The flags byte tells us which of the 283 * three datestamp fields are present in the data: 284 * <pre> 285 * bit0 - modify time 286 * bit1 - access time 287 * bit2 - create time 288 * </pre> 289 * Only first 3 bits of flags are used according to the 290 * latest version of the spec (December 2012). 291 * 292 * @return flags byte indicating which of the 293 * three datestamp fields are present. 294 */ 295 public byte getFlags() { return flags; } 296 297 /** 298 * Returns whether bit0 of the flags byte is set or not, 299 * which should correspond to the presence or absence of 300 * a modify timestamp in this particular zip entry. 301 * 302 * @return true if bit0 of the flags byte is set. 303 */ 304 public boolean isBit0_modifyTimePresent() { return bit0_modifyTimePresent; } 305 306 /** 307 * Returns whether bit1 of the flags byte is set or not, 308 * which should correspond to the presence or absence of 309 * a "last access" timestamp in this particular zip entry. 310 * 311 * @return true if bit1 of the flags byte is set. 312 */ 313 public boolean isBit1_accessTimePresent() { return bit1_accessTimePresent; } 314 315 /** 316 * Returns whether bit2 of the flags byte is set or not, 317 * which should correspond to the presence or absence of 318 * a create timestamp in this particular zip entry. 319 * 320 * @return true if bit2 of the flags byte is set. 321 */ 322 public boolean isBit2_createTimePresent() { return bit2_createTimePresent; } 323 324 /** 325 * Returns the modify time (seconds since epoch) of this zip entry 326 * as a ZipLong object, or null if no such timestamp exists in the 327 * zip entry. 328 * 329 * @return modify time (seconds since epoch) or null. 330 */ 331 public ZipLong getModifyTime() { return modifyTime; } 332 333 /** 334 * Returns the access time (seconds since epoch) of this zip entry 335 * as a ZipLong object, or null if no such timestamp exists in the 336 * zip entry. 337 * 338 * @return access time (seconds since epoch) or null. 339 */ 340 public ZipLong getAccessTime() { return accessTime; } 341 342 /** 343 * <p> 344 * Returns the create time (seconds since epoch) of this zip entry 345 * as a ZipLong object, or null if no such timestamp exists in the 346 * zip entry. 347 * </p><p> 348 * Note: modern linux file systems (e.g., ext2) 349 * do not appear to store a "create time" value, and so 350 * it's usually omitted altogether in the zip extra 351 * field. Perhaps other unix systems track this. 352 * 353 * @return create time (seconds since epoch) or null. 354 */ 355 public ZipLong getCreateTime() { return createTime; } 356 357 /** 358 * Returns the modify time as a java.util.Date 359 * of this zip entry, or null if no such timestamp exists in the zip entry. 360 * The milliseconds are always zeroed out, since the underlying data 361 * offers only per-second precision. 362 * 363 * @return modify time as java.util.Date or null. 364 */ 365 public Date getModifyJavaTime() { 366 return modifyTime != null ? new Date(modifyTime.getValue() * 1000) : null; 367 } 368 369 /** 370 * Returns the access time as a java.util.Date 371 * of this zip entry, or null if no such timestamp exists in the zip entry. 372 * The milliseconds are always zeroed out, since the underlying data 373 * offers only per-second precision. 374 * 375 * @return access time as java.util.Date or null. 376 */ 377 public Date getAccessJavaTime() { 378 return accessTime != null ? new Date(accessTime.getValue() * 1000) : null; 379 } 380 381 /** 382 * <p> 383 * Returns the create time as a a java.util.Date 384 * of this zip entry, or null if no such timestamp exists in the zip entry. 385 * The milliseconds are always zeroed out, since the underlying data 386 * offers only per-second precision. 387 * </p><p> 388 * Note: modern linux file systems (e.g., ext2) 389 * do not appear to store a "create time" value, and so 390 * it's usually omitted altogether in the zip extra 391 * field. Perhaps other unix systems track this. 392 * 393 * @return create time as java.util.Date or null. 394 */ 395 public Date getCreateJavaTime() { 396 return createTime != null ? new Date(createTime.getValue() * 1000) : null; 397 } 398 399 /** 400 * <p> 401 * Sets the modify time (seconds since epoch) of this zip entry 402 * using a ZipLong object. 403 * </p><p> 404 * Note: the setters for flags and timestamps are decoupled. 405 * Even if the timestamp is not-null, it will only be written 406 * out if the corresponding bit in the flags is also set. 407 * </p> 408 * 409 * @param l ZipLong of the modify time (seconds per epoch) 410 */ 411 public void setModifyTime(ZipLong l) { 412 bit0_modifyTimePresent = l != null; 413 flags = (byte) (l != null ? (flags | MODIFY_TIME_BIT) 414 : (flags & ~MODIFY_TIME_BIT)); 415 this.modifyTime = l; 416 } 417 418 /** 419 * <p> 420 * Sets the access time (seconds since epoch) of this zip entry 421 * using a ZipLong object 422 * </p><p> 423 * Note: the setters for flags and timestamps are decoupled. 424 * Even if the timestamp is not-null, it will only be written 425 * out if the corresponding bit in the flags is also set. 426 * </p> 427 * 428 * @param l ZipLong of the access time (seconds per epoch) 429 */ 430 public void setAccessTime(ZipLong l) { 431 bit1_accessTimePresent = l != null; 432 flags = (byte) (l != null ? (flags | ACCESS_TIME_BIT) 433 : (flags & ~ACCESS_TIME_BIT)); 434 this.accessTime = l; 435 } 436 437 /** 438 * <p> 439 * Sets the create time (seconds since epoch) of this zip entry 440 * using a ZipLong object 441 * </p><p> 442 * Note: the setters for flags and timestamps are decoupled. 443 * Even if the timestamp is not-null, it will only be written 444 * out if the corresponding bit in the flags is also set. 445 * </p> 446 * 447 * @param l ZipLong of the create time (seconds per epoch) 448 */ 449 public void setCreateTime(ZipLong l) { 450 bit2_createTimePresent = l != null; 451 flags = (byte) (l != null ? (flags | CREATE_TIME_BIT) 452 : (flags & ~CREATE_TIME_BIT)); 453 this.createTime = l; 454 } 455 456 /** 457 * <p> 458 * Sets the modify time as a java.util.Date 459 * of this zip entry. Supplied value is truncated to per-second 460 * precision (milliseconds zeroed-out). 461 * </p><p> 462 * Note: the setters for flags and timestamps are decoupled. 463 * Even if the timestamp is not-null, it will only be written 464 * out if the corresponding bit in the flags is also set. 465 * </p> 466 * 467 * @param d modify time as java.util.Date 468 */ 469 public void setModifyJavaTime(Date d) { setModifyTime(dateToZipLong(d)); } 470 471 /** 472 * <p> 473 * Sets the access time as a java.util.Date 474 * of this zip entry. Supplied value is truncated to per-second 475 * precision (milliseconds zeroed-out). 476 * </p><p> 477 * Note: the setters for flags and timestamps are decoupled. 478 * Even if the timestamp is not-null, it will only be written 479 * out if the corresponding bit in the flags is also set. 480 * </p> 481 * 482 * @param d access time as java.util.Date 483 */ 484 public void setAccessJavaTime(Date d) { setAccessTime(dateToZipLong(d)); } 485 486 /** 487 * <p> 488 * Sets the create time as a java.util.Date 489 * of this zip entry. Supplied value is truncated to per-second 490 * precision (milliseconds zeroed-out). 491 * </p><p> 492 * Note: the setters for flags and timestamps are decoupled. 493 * Even if the timestamp is not-null, it will only be written 494 * out if the corresponding bit in the flags is also set. 495 * </p> 496 * 497 * @param d create time as java.util.Date 498 */ 499 public void setCreateJavaTime(Date d) { setCreateTime(dateToZipLong(d)); } 500 501 /** 502 * Utility method converts java.util.Date (milliseconds since epoch) 503 * into a ZipLong (seconds since epoch). 504 * <p/> 505 * Also makes sure the converted ZipLong is not too big to fit 506 * in 32 unsigned bits. 507 * 508 * @param d java.util.Date to convert to ZipLong 509 * @return ZipLong 510 */ 511 private static ZipLong dateToZipLong(final Date d) { 512 if (d == null) { return null; } 513 514 final long TWO_TO_32 = 0x100000000L; 515 final long l = d.getTime() / 1000; 516 if (l >= TWO_TO_32) { 517 throw new IllegalArgumentException("Cannot set an X5455 timestamp larger than 2^32: " + l); 518 } 519 return new ZipLong(l); 520 } 521 522 /** 523 * Returns a String representation of this class useful for 524 * debugging purposes. 525 * 526 * @return A String representation of this class useful for 527 * debugging purposes. 528 */ 529 @Override 530 public String toString() { 531 StringBuilder buf = new StringBuilder(); 532 buf.append("0x5455 Zip Extra Field: Flags="); 533 buf.append(Integer.toBinaryString(ZipUtil.unsignedIntToSignedByte(flags))).append(" "); 534 if (bit0_modifyTimePresent && modifyTime != null) { 535 Date m = getModifyJavaTime(); 536 buf.append(" Modify:[").append(m).append("] "); 537 } 538 if (bit1_accessTimePresent && accessTime != null) { 539 Date a = getAccessJavaTime(); 540 buf.append(" Access:[").append(a).append("] "); 541 } 542 if (bit2_createTimePresent && createTime != null) { 543 Date c = getCreateJavaTime(); 544 buf.append(" Create:[").append(c).append("] "); 545 } 546 return buf.toString(); 547 } 548 549 @Override 550 public Object clone() throws CloneNotSupportedException { 551 return super.clone(); 552 } 553 554 @Override 555 public boolean equals(Object o) { 556 if (o instanceof X5455_ExtendedTimestamp) { 557 X5455_ExtendedTimestamp xf = (X5455_ExtendedTimestamp) o; 558 559 // The ZipLong==ZipLong clauses handle the cases where both are null. 560 // and only last 3 bits of flags matter. 561 return ((flags & 0x07) == (xf.flags & 0x07)) && 562 (modifyTime == xf.modifyTime || (modifyTime != null && modifyTime.equals(xf.modifyTime))) && 563 (accessTime == xf.accessTime || (accessTime != null && accessTime.equals(xf.accessTime))) && 564 (createTime == xf.createTime || (createTime != null && createTime.equals(xf.createTime))); 565 } else { 566 return false; 567 } 568 } 569 570 @Override 571 public int hashCode() { 572 int hc = (-123 * (flags & 0x07)); // only last 3 bits of flags matter 573 if (modifyTime != null) { 574 hc ^= modifyTime.hashCode(); 575 } 576 if (accessTime != null) { 577 // Since accessTime is often same as modifyTime, 578 // this prevents them from XOR negating each other. 579 hc ^= Integer.rotateLeft(accessTime.hashCode(), 11); 580 } 581 if (createTime != null) { 582 hc ^= Integer.rotateLeft(createTime.hashCode(), 22); 583 } 584 return hc; 585 } 586 587}