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.Arrays; 023import java.util.Date; 024import java.util.zip.ZipException; 025 026/** 027 * <p>An extra field that stores additional file and directory timestamp data 028 * for zip entries. Each zip entry can include up to three timestamps 029 * (modify, access, create*). The timestamps are stored as 32 bit signed 030 * integers representing seconds since UNIX epoch (Jan 1st, 1970, UTC). 031 * This field improves on zip's default timestamp granularity, since it 032 * allows one to store additional timestamps, and, in addition, the timestamps 033 * are stored using per-second granularity (zip's default behavior can only store 034 * timestamps to the nearest <em>even</em> second). 035 * </p><p> 036 * Unfortunately, 32 (signed) bits can only store dates up to the year 2037, 037 * and so this extra field will eventually be obsolete. Enjoy it while it lasts! 038 * </p> 039 * <ul> 040 * <li><b>modifyTime:</b> 041 * most recent time of file/directory modification 042 * (or file/dir creation if the entry has not been 043 * modified since it was created). 044 * </li> 045 * <li><b>accessTime:</b> 046 * most recent time file/directory was opened 047 * (e.g., read from disk). Many people disable 048 * their operating systems from updating this value 049 * using the NOATIME mount option to optimize disk behavior, 050 * and thus it's not always reliable. In those cases 051 * it's always equal to modifyTime. 052 * </li> 053 * <li><b>*createTime:</b> 054 * modern linux file systems (e.g., ext2 and newer) 055 * do not appear to store a value like this, and so 056 * it's usually omitted altogether in the zip extra 057 * field. Perhaps other unix systems track this. 058 * </li></ul> 059 * <p> 060 * We're using the field definition given in Info-Zip's source archive: 061 * zip-3.0.tar.gz/proginfo/extrafld.txt 062 * </p> 063 * <pre> 064 * Value Size Description 065 * ----- ---- ----------- 066 * 0x5455 Short tag for this extra block type ("UT") 067 * TSize Short total data size for this block 068 * Flags Byte info bits 069 * (ModTime) Long time of last modification (UTC/GMT) 070 * (AcTime) Long time of last access (UTC/GMT) 071 * (CrTime) Long time of original creation (UTC/GMT) 072 * 073 * Central-header version: 074 * 075 * Value Size Description 076 * ----- ---- ----------- 077 * 0x5455 Short tag for this extra block type ("UT") 078 * TSize Short total data size for this block 079 * Flags Byte info bits (refers to local header!) 080 * (ModTime) Long time of last modification (UTC/GMT) 081 * </pre> 082 * @since 1.5 083 */ 084public class X5455_ExtendedTimestamp implements ZipExtraField, Cloneable, Serializable { 085 private static final ZipShort HEADER_ID = new ZipShort(0x5455); 086 private static final long serialVersionUID = 1L; 087 088 /** 089 * The bit set inside the flags by when the last modification time 090 * is present in this extra field. 091 */ 092 public static final byte MODIFY_TIME_BIT = 1; 093 /** 094 * The bit set inside the flags by when the lasr access time is 095 * present in this extra field. 096 */ 097 public static final byte ACCESS_TIME_BIT = 2; 098 /** 099 * The bit set inside the flags by when the original creation time 100 * is present in this extra field. 101 */ 102 public static final byte CREATE_TIME_BIT = 4; 103 104 // The 3 boolean fields (below) come from this flags byte. The remaining 5 bits 105 // are ignored according to the current version of the spec (December 2012). 106 private byte flags; 107 108 // Note: even if bit1 and bit2 are set, the Central data will still not contain 109 // access/create fields: only local data ever holds those! This causes 110 // some of our implementation to look a little odd, with seemingly spurious 111 // != null and length checks. 112 private boolean bit0_modifyTimePresent; 113 private boolean bit1_accessTimePresent; 114 private boolean bit2_createTimePresent; 115 116 private ZipLong modifyTime; 117 private ZipLong accessTime; 118 private ZipLong createTime; 119 120 /** 121 * Constructor for X5455_ExtendedTimestamp. 122 */ 123 public X5455_ExtendedTimestamp() {} 124 125 /** 126 * The Header-ID. 127 * 128 * @return the value for the header id for this extrafield 129 */ 130 @Override 131 public ZipShort getHeaderId() { 132 return HEADER_ID; 133 } 134 135 /** 136 * Length of the extra field in the local file data - without 137 * Header-ID or length specifier. 138 * 139 * @return a <code>ZipShort</code> for the length of the data of this extra field 140 */ 141 @Override 142 public ZipShort getLocalFileDataLength() { 143 return new ZipShort(1 + 144 (bit0_modifyTimePresent ? 4 : 0) + 145 (bit1_accessTimePresent && accessTime != null ? 4 : 0) + 146 (bit2_createTimePresent && createTime != null ? 4 : 0) 147 ); 148 } 149 150 /** 151 * Length of the extra field in the local file data - without 152 * Header-ID or length specifier. 153 * 154 * <p>For X5455 the central length is often smaller than the 155 * local length, because central cannot contain access or create 156 * timestamps.</p> 157 * 158 * @return a <code>ZipShort</code> for the length of the data of this extra field 159 */ 160 @Override 161 public ZipShort getCentralDirectoryLength() { 162 return new ZipShort(1 + 163 (bit0_modifyTimePresent ? 4 : 0) 164 ); 165 } 166 167 /** 168 * The actual data to put into local file data - without Header-ID 169 * or length specifier. 170 * 171 * @return get the data 172 */ 173 @Override 174 public byte[] getLocalFileDataData() { 175 final byte[] data = new byte[getLocalFileDataLength().getValue()]; 176 int pos = 0; 177 data[pos++] = 0; 178 if (bit0_modifyTimePresent) { 179 data[0] |= MODIFY_TIME_BIT; 180 System.arraycopy(modifyTime.getBytes(), 0, data, pos, 4); 181 pos += 4; 182 } 183 if (bit1_accessTimePresent && accessTime != null) { 184 data[0] |= ACCESS_TIME_BIT; 185 System.arraycopy(accessTime.getBytes(), 0, data, pos, 4); 186 pos += 4; 187 } 188 if (bit2_createTimePresent && createTime != null) { 189 data[0] |= CREATE_TIME_BIT; 190 System.arraycopy(createTime.getBytes(), 0, data, pos, 4); 191 pos += 4; // NOSONAR - assignment as documentation 192 } 193 return data; 194 } 195 196 /** 197 * The actual data to put into central directory data - without Header-ID 198 * or length specifier. 199 * 200 * @return the central directory data 201 */ 202 @Override 203 public byte[] getCentralDirectoryData() { 204 // Truncate out create & access time (last 8 bytes) from 205 // the copy of the local data we obtained: 206 return Arrays.copyOf(getLocalFileDataData(), getCentralDirectoryLength().getValue()); 207 } 208 209 /** 210 * Populate data from this array as if it was in local file data. 211 * 212 * @param data an array of bytes 213 * @param offset the start offset 214 * @param length the number of bytes in the array from offset 215 * @throws java.util.zip.ZipException on error 216 */ 217 @Override 218 public void parseFromLocalFileData( 219 final byte[] data, int offset, final int length 220 ) throws ZipException { 221 reset(); 222 if (length < 1) { 223 throw new ZipException("X5455_ExtendedTimestamp too short, only " + length + " bytes"); 224 } 225 final int len = offset + length; 226 setFlags(data[offset++]); 227 if (bit0_modifyTimePresent && offset + 4 <= len) { 228 modifyTime = new ZipLong(data, offset); 229 offset += 4; 230 } else { 231 bit0_modifyTimePresent = false; 232 } 233 if (bit1_accessTimePresent && offset + 4 <= len) { 234 accessTime = new ZipLong(data, offset); 235 offset += 4; 236 } else { 237 bit1_accessTimePresent = false; 238 } 239 if (bit2_createTimePresent && offset + 4 <= len) { 240 createTime = new ZipLong(data, offset); 241 offset += 4; // NOSONAR - assignment as documentation 242 } else { 243 bit2_createTimePresent = false; 244 } 245 } 246 247 /** 248 * Doesn't do anything special since this class always uses the 249 * same parsing logic for both central directory and local file data. 250 */ 251 @Override 252 public void parseFromCentralDirectoryData( 253 final byte[] buffer, final int offset, final int length 254 ) throws ZipException { 255 reset(); 256 parseFromLocalFileData(buffer, offset, length); 257 } 258 259 /** 260 * Reset state back to newly constructed state. Helps us make sure 261 * parse() calls always generate clean results. 262 */ 263 private void reset() { 264 setFlags((byte) 0); 265 this.modifyTime = null; 266 this.accessTime = null; 267 this.createTime = null; 268 } 269 270 /** 271 * Sets flags byte. The flags byte tells us which of the 272 * three datestamp fields are present in the data: 273 * <pre> 274 * bit0 - modify time 275 * bit1 - access time 276 * bit2 - create time 277 * </pre> 278 * Only first 3 bits of flags are used according to the 279 * latest version of the spec (December 2012). 280 * 281 * @param flags flags byte indicating which of the 282 * three datestamp fields are present. 283 */ 284 public void setFlags(final byte flags) { 285 this.flags = flags; 286 this.bit0_modifyTimePresent = (flags & MODIFY_TIME_BIT) == MODIFY_TIME_BIT; 287 this.bit1_accessTimePresent = (flags & ACCESS_TIME_BIT) == ACCESS_TIME_BIT; 288 this.bit2_createTimePresent = (flags & CREATE_TIME_BIT) == CREATE_TIME_BIT; 289 } 290 291 /** 292 * Gets flags byte. The flags byte tells us which of the 293 * three datestamp fields are present in the data: 294 * <pre> 295 * bit0 - modify time 296 * bit1 - access time 297 * bit2 - create time 298 * </pre> 299 * Only first 3 bits of flags are used according to the 300 * latest version of the spec (December 2012). 301 * 302 * @return flags byte indicating which of the 303 * three datestamp fields are present. 304 */ 305 public byte getFlags() { return flags; } 306 307 /** 308 * Returns whether bit0 of the flags byte is set or not, 309 * which should correspond to the presence or absence of 310 * a modify timestamp in this particular zip entry. 311 * 312 * @return true if bit0 of the flags byte is set. 313 */ 314 public boolean isBit0_modifyTimePresent() { return bit0_modifyTimePresent; } 315 316 /** 317 * Returns whether bit1 of the flags byte is set or not, 318 * which should correspond to the presence or absence of 319 * a "last access" timestamp in this particular zip entry. 320 * 321 * @return true if bit1 of the flags byte is set. 322 */ 323 public boolean isBit1_accessTimePresent() { return bit1_accessTimePresent; } 324 325 /** 326 * Returns whether bit2 of the flags byte is set or not, 327 * which should correspond to the presence or absence of 328 * a create timestamp in this particular zip entry. 329 * 330 * @return true if bit2 of the flags byte is set. 331 */ 332 public boolean isBit2_createTimePresent() { return bit2_createTimePresent; } 333 334 /** 335 * Returns the modify time (seconds since epoch) of this zip entry 336 * as a ZipLong object, or null if no such timestamp exists in the 337 * zip entry. 338 * 339 * @return modify time (seconds since epoch) or null. 340 */ 341 public ZipLong getModifyTime() { return modifyTime; } 342 343 /** 344 * Returns the access 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 * 348 * @return access time (seconds since epoch) or null. 349 */ 350 public ZipLong getAccessTime() { return accessTime; } 351 352 /** 353 * <p> 354 * Returns the create time (seconds since epoch) of this zip entry 355 * as a ZipLong object, or null if no such timestamp exists in the 356 * zip entry. 357 * </p><p> 358 * Note: modern linux file systems (e.g., ext2) 359 * do not appear to store a "create time" value, and so 360 * it's usually omitted altogether in the zip extra 361 * field. Perhaps other unix systems track this. 362 * 363 * @return create time (seconds since epoch) or null. 364 */ 365 public ZipLong getCreateTime() { return createTime; } 366 367 /** 368 * Returns the modify time as a java.util.Date 369 * of this zip entry, or null if no such timestamp exists in the zip entry. 370 * The milliseconds are always zeroed out, since the underlying data 371 * offers only per-second precision. 372 * 373 * @return modify time as java.util.Date or null. 374 */ 375 public Date getModifyJavaTime() { 376 return zipLongToDate(modifyTime); 377 } 378 379 /** 380 * Returns the access time as a java.util.Date 381 * of this zip entry, or null if no such timestamp exists in the zip entry. 382 * The milliseconds are always zeroed out, since the underlying data 383 * offers only per-second precision. 384 * 385 * @return access time as java.util.Date or null. 386 */ 387 public Date getAccessJavaTime() { 388 return zipLongToDate(accessTime); 389 } 390 391 /** 392 * <p> 393 * Returns the create time as a a java.util.Date 394 * of this zip entry, or null if no such timestamp exists in the zip entry. 395 * The milliseconds are always zeroed out, since the underlying data 396 * offers only per-second precision. 397 * </p><p> 398 * Note: modern linux file systems (e.g., ext2) 399 * do not appear to store a "create time" value, and so 400 * it's usually omitted altogether in the zip extra 401 * field. Perhaps other unix systems track this. 402 * 403 * @return create time as java.util.Date or null. 404 */ 405 public Date getCreateJavaTime() { 406 return zipLongToDate(createTime); 407 } 408 409 /** 410 * <p> 411 * Sets the modify time (seconds since epoch) of this zip entry 412 * using a ZipLong object. 413 * </p><p> 414 * Note: the setters for flags and timestamps are decoupled. 415 * Even if the timestamp is not-null, it will only be written 416 * out if the corresponding bit in the flags is also set. 417 * </p> 418 * 419 * @param l ZipLong of the modify time (seconds per epoch) 420 */ 421 public void setModifyTime(final ZipLong l) { 422 bit0_modifyTimePresent = l != null; 423 flags = (byte) (l != null ? (flags | MODIFY_TIME_BIT) 424 : (flags & ~MODIFY_TIME_BIT)); 425 this.modifyTime = l; 426 } 427 428 /** 429 * <p> 430 * Sets the access time (seconds since epoch) of this zip entry 431 * using a ZipLong object 432 * </p><p> 433 * Note: the setters for flags and timestamps are decoupled. 434 * Even if the timestamp is not-null, it will only be written 435 * out if the corresponding bit in the flags is also set. 436 * </p> 437 * 438 * @param l ZipLong of the access time (seconds per epoch) 439 */ 440 public void setAccessTime(final ZipLong l) { 441 bit1_accessTimePresent = l != null; 442 flags = (byte) (l != null ? (flags | ACCESS_TIME_BIT) 443 : (flags & ~ACCESS_TIME_BIT)); 444 this.accessTime = l; 445 } 446 447 /** 448 * <p> 449 * Sets the create time (seconds since epoch) of this zip entry 450 * using a ZipLong object 451 * </p><p> 452 * Note: the setters for flags and timestamps are decoupled. 453 * Even if the timestamp is not-null, it will only be written 454 * out if the corresponding bit in the flags is also set. 455 * </p> 456 * 457 * @param l ZipLong of the create time (seconds per epoch) 458 */ 459 public void setCreateTime(final ZipLong l) { 460 bit2_createTimePresent = l != null; 461 flags = (byte) (l != null ? (flags | CREATE_TIME_BIT) 462 : (flags & ~CREATE_TIME_BIT)); 463 this.createTime = l; 464 } 465 466 /** 467 * <p> 468 * Sets the modify time as a java.util.Date 469 * of this zip entry. Supplied value is truncated to per-second 470 * precision (milliseconds zeroed-out). 471 * </p><p> 472 * Note: the setters for flags and timestamps are decoupled. 473 * Even if the timestamp is not-null, it will only be written 474 * out if the corresponding bit in the flags is also set. 475 * </p> 476 * 477 * @param d modify time as java.util.Date 478 */ 479 public void setModifyJavaTime(final Date d) { setModifyTime(dateToZipLong(d)); } 480 481 /** 482 * <p> 483 * Sets the access time as a java.util.Date 484 * of this zip entry. Supplied value is truncated to per-second 485 * precision (milliseconds zeroed-out). 486 * </p><p> 487 * Note: the setters for flags and timestamps are decoupled. 488 * Even if the timestamp is not-null, it will only be written 489 * out if the corresponding bit in the flags is also set. 490 * </p> 491 * 492 * @param d access time as java.util.Date 493 */ 494 public void setAccessJavaTime(final Date d) { setAccessTime(dateToZipLong(d)); } 495 496 /** 497 * <p> 498 * Sets the create time as a java.util.Date 499 * of this zip entry. Supplied value is truncated to per-second 500 * precision (milliseconds zeroed-out). 501 * </p><p> 502 * Note: the setters for flags and timestamps are decoupled. 503 * Even if the timestamp is not-null, it will only be written 504 * out if the corresponding bit in the flags is also set. 505 * </p> 506 * 507 * @param d create time as java.util.Date 508 */ 509 public void setCreateJavaTime(final Date d) { setCreateTime(dateToZipLong(d)); } 510 511 /** 512 * Utility method converts java.util.Date (milliseconds since epoch) 513 * into a ZipLong (seconds since epoch). 514 * <p/> 515 * Also makes sure the converted ZipLong is not too big to fit 516 * in 32 unsigned bits. 517 * 518 * @param d java.util.Date to convert to ZipLong 519 * @return ZipLong 520 */ 521 private static ZipLong dateToZipLong(final Date d) { 522 if (d == null) { return null; } 523 524 return unixTimeToZipLong(d.getTime() / 1000); 525 } 526 527 /** 528 * Returns a String representation of this class useful for 529 * debugging purposes. 530 * 531 * @return A String representation of this class useful for 532 * debugging purposes. 533 */ 534 @Override 535 public String toString() { 536 final StringBuilder buf = new StringBuilder(); 537 buf.append("0x5455 Zip Extra Field: Flags="); 538 buf.append(Integer.toBinaryString(ZipUtil.unsignedIntToSignedByte(flags))).append(" "); 539 if (bit0_modifyTimePresent && modifyTime != null) { 540 final Date m = getModifyJavaTime(); 541 buf.append(" Modify:[").append(m).append("] "); 542 } 543 if (bit1_accessTimePresent && accessTime != null) { 544 final Date a = getAccessJavaTime(); 545 buf.append(" Access:[").append(a).append("] "); 546 } 547 if (bit2_createTimePresent && createTime != null) { 548 final Date c = getCreateJavaTime(); 549 buf.append(" Create:[").append(c).append("] "); 550 } 551 return buf.toString(); 552 } 553 554 @Override 555 public Object clone() throws CloneNotSupportedException { 556 return super.clone(); 557 } 558 559 @Override 560 public boolean equals(final Object o) { 561 if (o instanceof X5455_ExtendedTimestamp) { 562 final X5455_ExtendedTimestamp xf = (X5455_ExtendedTimestamp) o; 563 564 // The ZipLong==ZipLong clauses handle the cases where both are null. 565 // and only last 3 bits of flags matter. 566 return ((flags & 0x07) == (xf.flags & 0x07)) && 567 (modifyTime == xf.modifyTime || (modifyTime != null && modifyTime.equals(xf.modifyTime))) && 568 (accessTime == xf.accessTime || (accessTime != null && accessTime.equals(xf.accessTime))) && 569 (createTime == xf.createTime || (createTime != null && createTime.equals(xf.createTime))); 570 } 571 return false; 572 } 573 574 @Override 575 public int hashCode() { 576 int hc = (-123 * (flags & 0x07)); // only last 3 bits of flags matter 577 if (modifyTime != null) { 578 hc ^= modifyTime.hashCode(); 579 } 580 if (accessTime != null) { 581 // Since accessTime is often same as modifyTime, 582 // this prevents them from XOR negating each other. 583 hc ^= Integer.rotateLeft(accessTime.hashCode(), 11); 584 } 585 if (createTime != null) { 586 hc ^= Integer.rotateLeft(createTime.hashCode(), 22); 587 } 588 return hc; 589 } 590 591 private static Date zipLongToDate(final ZipLong unixTime) { 592 return unixTime != null ? new Date(unixTime.getIntValue() * 1000L) : null; 593 } 594 595 private static ZipLong unixTimeToZipLong(final long l) { 596 if (l < Integer.MIN_VALUE || l > Integer.MAX_VALUE) { 597 throw new IllegalArgumentException("X5455 timestamps must fit in a signed 32 bit integer: " + l); 598 } 599 return new ZipLong(l); 600 } 601 602}