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 signed 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 (signed) bits can only store dates up to the year 2037, 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 @Override 130 public ZipShort getHeaderId() { 131 return HEADER_ID; 132 } 133 134 /** 135 * Length of the extra field in the local file data - without 136 * Header-ID or length specifier. 137 * 138 * @return a <code>ZipShort</code> for the length of the data of this extra field 139 */ 140 @Override 141 public ZipShort getLocalFileDataLength() { 142 return new ZipShort(1 + 143 (bit0_modifyTimePresent ? 4 : 0) + 144 (bit1_accessTimePresent && accessTime != null ? 4 : 0) + 145 (bit2_createTimePresent && createTime != null ? 4 : 0) 146 ); 147 } 148 149 /** 150 * Length of the extra field in the local file data - without 151 * Header-ID or length specifier. 152 * 153 * <p>For X5455 the central length is often smaller than the 154 * local length, because central cannot contain access or create 155 * timestamps.</p> 156 * 157 * @return a <code>ZipShort</code> for the length of the data of this extra field 158 */ 159 @Override 160 public ZipShort getCentralDirectoryLength() { 161 return new ZipShort(1 + 162 (bit0_modifyTimePresent ? 4 : 0) 163 ); 164 } 165 166 /** 167 * The actual data to put into local file data - without Header-ID 168 * or length specifier. 169 * 170 * @return get the data 171 */ 172 @Override 173 public byte[] getLocalFileDataData() { 174 final byte[] data = new byte[getLocalFileDataLength().getValue()]; 175 int pos = 0; 176 data[pos++] = 0; 177 if (bit0_modifyTimePresent) { 178 data[0] |= MODIFY_TIME_BIT; 179 System.arraycopy(modifyTime.getBytes(), 0, data, pos, 4); 180 pos += 4; 181 } 182 if (bit1_accessTimePresent && accessTime != null) { 183 data[0] |= ACCESS_TIME_BIT; 184 System.arraycopy(accessTime.getBytes(), 0, data, pos, 4); 185 pos += 4; 186 } 187 if (bit2_createTimePresent && createTime != null) { 188 data[0] |= CREATE_TIME_BIT; 189 System.arraycopy(createTime.getBytes(), 0, data, pos, 4); 190 pos += 4; // NOSONAR - assignment as documentation 191 } 192 return data; 193 } 194 195 /** 196 * The actual data to put into central directory data - without Header-ID 197 * or length specifier. 198 * 199 * @return the central directory data 200 */ 201 @Override 202 public byte[] getCentralDirectoryData() { 203 final byte[] centralData = new byte[getCentralDirectoryLength().getValue()]; 204 final byte[] localData = getLocalFileDataData(); 205 206 // Truncate out create & access time (last 8 bytes) from 207 // the copy of the local data we obtained: 208 System.arraycopy(localData, 0, centralData, 0, centralData.length); 209 return centralData; 210 } 211 212 /** 213 * Populate data from this array as if it was in local file data. 214 * 215 * @param data an array of bytes 216 * @param offset the start offset 217 * @param length the number of bytes in the array from offset 218 * @throws java.util.zip.ZipException on error 219 */ 220 @Override 221 public void parseFromLocalFileData( 222 final byte[] data, int offset, final int length 223 ) throws ZipException { 224 reset(); 225 final int len = offset + length; 226 setFlags(data[offset++]); 227 if (bit0_modifyTimePresent) { 228 modifyTime = new ZipLong(data, offset); 229 offset += 4; 230 } 231 232 // Notice the extra length check in case we are parsing the shorter 233 // central data field (for both access and create timestamps). 234 if (bit1_accessTimePresent && offset + 4 <= len) { 235 accessTime = new ZipLong(data, offset); 236 offset += 4; 237 } 238 if (bit2_createTimePresent && offset + 4 <= len) { 239 createTime = new ZipLong(data, offset); 240 offset += 4; // NOSONAR - assignment as documentation 241 } 242 } 243 244 /** 245 * Doesn't do anything special since this class always uses the 246 * same parsing logic for both central directory and local file data. 247 */ 248 @Override 249 public void parseFromCentralDirectoryData( 250 final byte[] buffer, final int offset, final int length 251 ) throws ZipException { 252 reset(); 253 parseFromLocalFileData(buffer, offset, length); 254 } 255 256 /** 257 * Reset state back to newly constructed state. Helps us make sure 258 * parse() calls always generate clean results. 259 */ 260 private void reset() { 261 setFlags((byte) 0); 262 this.modifyTime = null; 263 this.accessTime = null; 264 this.createTime = null; 265 } 266 267 /** 268 * Sets flags byte. The flags byte tells us which of the 269 * three datestamp fields are present in the data: 270 * <pre> 271 * bit0 - modify time 272 * bit1 - access time 273 * bit2 - create time 274 * </pre> 275 * Only first 3 bits of flags are used according to the 276 * latest version of the spec (December 2012). 277 * 278 * @param flags flags byte indicating which of the 279 * three datestamp fields are present. 280 */ 281 public void setFlags(final byte flags) { 282 this.flags = flags; 283 this.bit0_modifyTimePresent = (flags & MODIFY_TIME_BIT) == MODIFY_TIME_BIT; 284 this.bit1_accessTimePresent = (flags & ACCESS_TIME_BIT) == ACCESS_TIME_BIT; 285 this.bit2_createTimePresent = (flags & CREATE_TIME_BIT) == CREATE_TIME_BIT; 286 } 287 288 /** 289 * Gets flags byte. The flags byte tells us which of the 290 * three datestamp fields are present in the data: 291 * <pre> 292 * bit0 - modify time 293 * bit1 - access time 294 * bit2 - create time 295 * </pre> 296 * Only first 3 bits of flags are used according to the 297 * latest version of the spec (December 2012). 298 * 299 * @return flags byte indicating which of the 300 * three datestamp fields are present. 301 */ 302 public byte getFlags() { return flags; } 303 304 /** 305 * Returns whether bit0 of the flags byte is set or not, 306 * which should correspond to the presence or absence of 307 * a modify timestamp in this particular zip entry. 308 * 309 * @return true if bit0 of the flags byte is set. 310 */ 311 public boolean isBit0_modifyTimePresent() { return bit0_modifyTimePresent; } 312 313 /** 314 * Returns whether bit1 of the flags byte is set or not, 315 * which should correspond to the presence or absence of 316 * a "last access" timestamp in this particular zip entry. 317 * 318 * @return true if bit1 of the flags byte is set. 319 */ 320 public boolean isBit1_accessTimePresent() { return bit1_accessTimePresent; } 321 322 /** 323 * Returns whether bit2 of the flags byte is set or not, 324 * which should correspond to the presence or absence of 325 * a create timestamp in this particular zip entry. 326 * 327 * @return true if bit2 of the flags byte is set. 328 */ 329 public boolean isBit2_createTimePresent() { return bit2_createTimePresent; } 330 331 /** 332 * Returns the modify time (seconds since epoch) of this zip entry 333 * as a ZipLong object, or null if no such timestamp exists in the 334 * zip entry. 335 * 336 * @return modify time (seconds since epoch) or null. 337 */ 338 public ZipLong getModifyTime() { return modifyTime; } 339 340 /** 341 * Returns the access time (seconds since epoch) of this zip entry 342 * as a ZipLong object, or null if no such timestamp exists in the 343 * zip entry. 344 * 345 * @return access time (seconds since epoch) or null. 346 */ 347 public ZipLong getAccessTime() { return accessTime; } 348 349 /** 350 * <p> 351 * Returns the create time (seconds since epoch) of this zip entry 352 * as a ZipLong object, or null if no such timestamp exists in the 353 * zip entry. 354 * </p><p> 355 * Note: modern linux file systems (e.g., ext2) 356 * do not appear to store a "create time" value, and so 357 * it's usually omitted altogether in the zip extra 358 * field. Perhaps other unix systems track this. 359 * 360 * @return create time (seconds since epoch) or null. 361 */ 362 public ZipLong getCreateTime() { return createTime; } 363 364 /** 365 * Returns the modify time as a java.util.Date 366 * of this zip entry, or null if no such timestamp exists in the zip entry. 367 * The milliseconds are always zeroed out, since the underlying data 368 * offers only per-second precision. 369 * 370 * @return modify time as java.util.Date or null. 371 */ 372 public Date getModifyJavaTime() { 373 return zipLongToDate(modifyTime); 374 } 375 376 /** 377 * Returns the access time as a java.util.Date 378 * of this zip entry, or null if no such timestamp exists in the zip entry. 379 * The milliseconds are always zeroed out, since the underlying data 380 * offers only per-second precision. 381 * 382 * @return access time as java.util.Date or null. 383 */ 384 public Date getAccessJavaTime() { 385 return zipLongToDate(accessTime); 386 } 387 388 /** 389 * <p> 390 * Returns the create time as a a java.util.Date 391 * of this zip entry, or null if no such timestamp exists in the zip entry. 392 * The milliseconds are always zeroed out, since the underlying data 393 * offers only per-second precision. 394 * </p><p> 395 * Note: modern linux file systems (e.g., ext2) 396 * do not appear to store a "create time" value, and so 397 * it's usually omitted altogether in the zip extra 398 * field. Perhaps other unix systems track this. 399 * 400 * @return create time as java.util.Date or null. 401 */ 402 public Date getCreateJavaTime() { 403 return zipLongToDate(createTime); 404 } 405 406 /** 407 * <p> 408 * Sets the modify time (seconds since epoch) of this zip entry 409 * using a ZipLong object. 410 * </p><p> 411 * Note: the setters for flags and timestamps are decoupled. 412 * Even if the timestamp is not-null, it will only be written 413 * out if the corresponding bit in the flags is also set. 414 * </p> 415 * 416 * @param l ZipLong of the modify time (seconds per epoch) 417 */ 418 public void setModifyTime(final ZipLong l) { 419 bit0_modifyTimePresent = l != null; 420 flags = (byte) (l != null ? (flags | MODIFY_TIME_BIT) 421 : (flags & ~MODIFY_TIME_BIT)); 422 this.modifyTime = l; 423 } 424 425 /** 426 * <p> 427 * Sets the access time (seconds since epoch) of this zip entry 428 * using a ZipLong object 429 * </p><p> 430 * Note: the setters for flags and timestamps are decoupled. 431 * Even if the timestamp is not-null, it will only be written 432 * out if the corresponding bit in the flags is also set. 433 * </p> 434 * 435 * @param l ZipLong of the access time (seconds per epoch) 436 */ 437 public void setAccessTime(final ZipLong l) { 438 bit1_accessTimePresent = l != null; 439 flags = (byte) (l != null ? (flags | ACCESS_TIME_BIT) 440 : (flags & ~ACCESS_TIME_BIT)); 441 this.accessTime = l; 442 } 443 444 /** 445 * <p> 446 * Sets the create time (seconds since epoch) of this zip entry 447 * using a ZipLong object 448 * </p><p> 449 * Note: the setters for flags and timestamps are decoupled. 450 * Even if the timestamp is not-null, it will only be written 451 * out if the corresponding bit in the flags is also set. 452 * </p> 453 * 454 * @param l ZipLong of the create time (seconds per epoch) 455 */ 456 public void setCreateTime(final ZipLong l) { 457 bit2_createTimePresent = l != null; 458 flags = (byte) (l != null ? (flags | CREATE_TIME_BIT) 459 : (flags & ~CREATE_TIME_BIT)); 460 this.createTime = l; 461 } 462 463 /** 464 * <p> 465 * Sets the modify time as a java.util.Date 466 * of this zip entry. Supplied value is truncated to per-second 467 * precision (milliseconds zeroed-out). 468 * </p><p> 469 * Note: the setters for flags and timestamps are decoupled. 470 * Even if the timestamp is not-null, it will only be written 471 * out if the corresponding bit in the flags is also set. 472 * </p> 473 * 474 * @param d modify time as java.util.Date 475 */ 476 public void setModifyJavaTime(final Date d) { setModifyTime(dateToZipLong(d)); } 477 478 /** 479 * <p> 480 * Sets the access time as a java.util.Date 481 * of this zip entry. Supplied value is truncated to per-second 482 * precision (milliseconds zeroed-out). 483 * </p><p> 484 * Note: the setters for flags and timestamps are decoupled. 485 * Even if the timestamp is not-null, it will only be written 486 * out if the corresponding bit in the flags is also set. 487 * </p> 488 * 489 * @param d access time as java.util.Date 490 */ 491 public void setAccessJavaTime(final Date d) { setAccessTime(dateToZipLong(d)); } 492 493 /** 494 * <p> 495 * Sets the create time as a java.util.Date 496 * of this zip entry. Supplied value is truncated to per-second 497 * precision (milliseconds zeroed-out). 498 * </p><p> 499 * Note: the setters for flags and timestamps are decoupled. 500 * Even if the timestamp is not-null, it will only be written 501 * out if the corresponding bit in the flags is also set. 502 * </p> 503 * 504 * @param d create time as java.util.Date 505 */ 506 public void setCreateJavaTime(final Date d) { setCreateTime(dateToZipLong(d)); } 507 508 /** 509 * Utility method converts java.util.Date (milliseconds since epoch) 510 * into a ZipLong (seconds since epoch). 511 * <p/> 512 * Also makes sure the converted ZipLong is not too big to fit 513 * in 32 unsigned bits. 514 * 515 * @param d java.util.Date to convert to ZipLong 516 * @return ZipLong 517 */ 518 private static ZipLong dateToZipLong(final Date d) { 519 if (d == null) { return null; } 520 521 return unixTimeToZipLong(d.getTime() / 1000); 522 } 523 524 /** 525 * Returns a String representation of this class useful for 526 * debugging purposes. 527 * 528 * @return A String representation of this class useful for 529 * debugging purposes. 530 */ 531 @Override 532 public String toString() { 533 final StringBuilder buf = new StringBuilder(); 534 buf.append("0x5455 Zip Extra Field: Flags="); 535 buf.append(Integer.toBinaryString(ZipUtil.unsignedIntToSignedByte(flags))).append(" "); 536 if (bit0_modifyTimePresent && modifyTime != null) { 537 final Date m = getModifyJavaTime(); 538 buf.append(" Modify:[").append(m).append("] "); 539 } 540 if (bit1_accessTimePresent && accessTime != null) { 541 final Date a = getAccessJavaTime(); 542 buf.append(" Access:[").append(a).append("] "); 543 } 544 if (bit2_createTimePresent && createTime != null) { 545 final Date c = getCreateJavaTime(); 546 buf.append(" Create:[").append(c).append("] "); 547 } 548 return buf.toString(); 549 } 550 551 @Override 552 public Object clone() throws CloneNotSupportedException { 553 return super.clone(); 554 } 555 556 @Override 557 public boolean equals(final Object o) { 558 if (o instanceof X5455_ExtendedTimestamp) { 559 final X5455_ExtendedTimestamp xf = (X5455_ExtendedTimestamp) o; 560 561 // The ZipLong==ZipLong clauses handle the cases where both are null. 562 // and only last 3 bits of flags matter. 563 return ((flags & 0x07) == (xf.flags & 0x07)) && 564 (modifyTime == xf.modifyTime || (modifyTime != null && modifyTime.equals(xf.modifyTime))) && 565 (accessTime == xf.accessTime || (accessTime != null && accessTime.equals(xf.accessTime))) && 566 (createTime == xf.createTime || (createTime != null && createTime.equals(xf.createTime))); 567 } 568 return false; 569 } 570 571 @Override 572 public int hashCode() { 573 int hc = (-123 * (flags & 0x07)); // only last 3 bits of flags matter 574 if (modifyTime != null) { 575 hc ^= modifyTime.hashCode(); 576 } 577 if (accessTime != null) { 578 // Since accessTime is often same as modifyTime, 579 // this prevents them from XOR negating each other. 580 hc ^= Integer.rotateLeft(accessTime.hashCode(), 11); 581 } 582 if (createTime != null) { 583 hc ^= Integer.rotateLeft(createTime.hashCode(), 22); 584 } 585 return hc; 586 } 587 588 private static Date zipLongToDate(ZipLong unixTime) { 589 return unixTime != null ? new Date(unixTime.getIntValue() * 1000L) : null; 590 } 591 592 private static ZipLong unixTimeToZipLong(long l) { 593 if (l < Integer.MIN_VALUE || l > Integer.MAX_VALUE) { 594 throw new IllegalArgumentException("X5455 timestamps must fit in a signed 32 bit integer: " + l); 595 } 596 return new ZipLong(l); 597 } 598 599}