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.nio.file.attribute.FileTime;
023import java.util.Arrays;
024import java.util.Date;
025import java.util.Objects;
026import java.util.zip.ZipException;
027
028import org.apache.commons.compress.utils.TimeUtils;
029
030/**
031 * <p>
032 * An extra field that stores additional file and directory timestamp data for ZIP entries. Each ZIP entry can include up to three timestamps (modify, access,
033 * create*). The timestamps are stored as 32 bit signed integers representing seconds since UNIX epoch (Jan 1st, 1970, UTC). This field improves on ZIP's
034 * default timestamp granularity, since it allows one to store additional timestamps, and, in addition, the timestamps are stored using per-second granularity
035 * (zip's default behavior can only store timestamps to the nearest <em>even</em> second).
036 * </p>
037 * <p>
038 * Unfortunately, 32 (signed) bits can only store dates up to the year 2037, and so this extra field will eventually be obsolete. Enjoy it while it lasts!
039 * </p>
040 * <ul>
041 * <li><b>modifyTime:</b> most recent time of file/directory modification (or file/dir creation if the entry has not been modified since it was created).</li>
042 * <li><b>accessTime:</b> most recent time file/directory was opened (e.g., read from disk). Many people disable their operating systems from updating this
043 * value using the NOATIME mount option to optimize disk behavior, and thus it's not always reliable. In those cases it's always equal to modifyTime.</li>
044 * <li><b>*createTime:</b> modern Linux file systems (e.g., ext2 and newer) do not appear to store a value like this, and so it's usually omitted altogether in
045 * the ZIP extra field. Perhaps other Unix systems track this.</li>
046 * </ul>
047 * <p>
048 * We're using the field definition given in Info-Zip's source archive: zip-3.0.tar.gz/proginfo/extrafld.txt
049 * </p>
050 *
051 * <pre>
052 * Value         Size        Description
053 * -----         ----        -----------
054 * 0x5455        Short       tag for this extra block type ("UT")
055 * TSize         Short       total data size for this block
056 * Flags         Byte        info bits
057 * (ModTime)     Long        time of last modification (UTC/GMT)
058 * (AcTime)      Long        time of last access (UTC/GMT)
059 * (CrTime)      Long        time of original creation (UTC/GMT)
060 *
061 * Central-header version:
062 *
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 (refers to local header!)
068 * (ModTime)     Long        time of last modification (UTC/GMT)
069 * </pre>
070 *
071 * @since 1.5
072 */
073public class X5455_ExtendedTimestamp implements ZipExtraField, Cloneable, Serializable {
074    private static final long serialVersionUID = 1L;
075
076    /**
077     * The header ID for this extra field.
078     *
079     * @since 1.23
080     */
081    public static final ZipShort HEADER_ID = new ZipShort(0x5455);
082
083    /**
084     * The bit set inside the flags by when the last modification time is present in this extra field.
085     */
086    public static final byte MODIFY_TIME_BIT = 1;
087    /**
088     * The bit set inside the flags by when the lasr access time is present in this extra field.
089     */
090    public static final byte ACCESS_TIME_BIT = 2;
091    /**
092     * The bit set inside the flags by when the original creation time is present in this extra field.
093     */
094    public static final byte CREATE_TIME_BIT = 4;
095
096    /**
097     * Utility method converts java.util.Date (milliseconds since epoch) into a ZipLong (seconds since epoch).
098     * <p/>
099     * Also makes sure the converted ZipLong is not too big to fit in 32 unsigned bits.
100     *
101     * @param d java.util.Date to convert to ZipLong
102     * @return ZipLong
103     */
104    private static ZipLong dateToZipLong(final Date d) {
105        if (d == null) {
106            return null;
107        }
108        return unixTimeToZipLong(d.getTime() / 1000);
109    }
110
111    /**
112     * Utility method converts {@link FileTime} into a ZipLong (seconds since epoch).
113     * <p/>
114     * Also makes sure the converted ZipLong is not too big to fit in 32 unsigned bits.
115     *
116     * @param time {@link FileTime} to convert to ZipLong
117     * @return ZipLong
118     */
119    private static ZipLong fileTimeToZipLong(final FileTime time) {
120        return time == null ? null : unixTimeToZipLong(TimeUtils.toUnixTime(time));
121    }
122
123    private static FileTime unixTimeToFileTime(final ZipLong unixTime) {
124        return unixTime != null ? TimeUtils.unixTimeToFileTime(unixTime.getIntValue()) : null;
125    }
126    // The 3 boolean fields (below) come from this flag's byte. The remaining 5 bits
127    // are ignored according to the current version of the spec (December 2012).
128
129    private static ZipLong unixTimeToZipLong(final long unixTime) {
130        if (!TimeUtils.isUnixTime(unixTime)) {
131            throw new IllegalArgumentException("X5455 timestamps must fit in a signed 32 bit integer: " + unixTime);
132        }
133        return new ZipLong(unixTime);
134    }
135
136    private static Date zipLongToDate(final ZipLong unixTime) {
137        return unixTime != null ? new Date(unixTime.getIntValue() * 1000L) : null;
138    }
139
140    private byte flags;
141    // Note: even if bit1 and bit2 are set, the Central data will still not contain
142    // access/create fields: only local data ever holds those! This causes
143    // some of our implementation to look a little odd, with seemingly spurious
144    // != null and length checks.
145    private boolean bit0_modifyTimePresent;
146    private boolean bit1_accessTimePresent;
147
148    private boolean bit2_createTimePresent;
149
150    private ZipLong modifyTime;
151
152    private ZipLong accessTime;
153
154    private ZipLong createTime;
155
156    /**
157     * Constructor for X5455_ExtendedTimestamp.
158     */
159    public X5455_ExtendedTimestamp() {
160    }
161
162    @Override
163    public Object clone() throws CloneNotSupportedException {
164        return super.clone();
165    }
166
167    @Override
168    public boolean equals(final Object o) {
169        if (o instanceof X5455_ExtendedTimestamp) {
170            final X5455_ExtendedTimestamp xf = (X5455_ExtendedTimestamp) o;
171
172            // The ZipLong==ZipLong clauses handle the cases where both are null.
173            // and only last 3 bits of flags matter.
174            return (flags & 0x07) == (xf.flags & 0x07) && Objects.equals(modifyTime, xf.modifyTime) && Objects.equals(accessTime, xf.accessTime)
175                    && Objects.equals(createTime, xf.createTime);
176        }
177        return false;
178    }
179
180    /**
181     * Gets the access time as a {@link FileTime} of this ZIP entry, or null if no such timestamp exists in the ZIP entry. The milliseconds are always zeroed
182     * out, since the underlying data offers only per-second precision.
183     *
184     * @return modify time as {@link FileTime} or null.
185     * @since 1.23
186     */
187    public FileTime getAccessFileTime() {
188        return unixTimeToFileTime(accessTime);
189    }
190
191    /**
192     * Gets the access time as a java.util.Date of this ZIP entry, or null if no such timestamp exists in the ZIP entry. The milliseconds are always zeroed out,
193     * since the underlying data offers only per-second precision.
194     *
195     * @return access time as java.util.Date or null.
196     */
197    public Date getAccessJavaTime() {
198        return zipLongToDate(accessTime);
199    }
200
201    /**
202     * Gets the access time (seconds since epoch) of this ZIP entry as a ZipLong object, or null if no such timestamp exists in the ZIP entry.
203     *
204     * @return access time (seconds since epoch) or null.
205     */
206    public ZipLong getAccessTime() {
207        return accessTime;
208    }
209
210    /**
211     * Gets the actual data to put into central directory data - without Header-ID or length specifier.
212     *
213     * @return the central directory data
214     */
215    @Override
216    public byte[] getCentralDirectoryData() {
217        // Truncate out create & access time (last 8 bytes) from
218        // the copy of the local data we obtained:
219        return Arrays.copyOf(getLocalFileDataData(), getCentralDirectoryLength().getValue());
220    }
221
222    /**
223     * Gets the length of the extra field in the local file data - without Header-ID or length specifier.
224     *
225     * <p>
226     * For X5455 the central length is often smaller than the local length, because central cannot contain access or create timestamps.
227     * </p>
228     *
229     * @return a {@code ZipShort} for the length of the data of this extra field
230     */
231    @Override
232    public ZipShort getCentralDirectoryLength() {
233        return new ZipShort(1 + (bit0_modifyTimePresent ? 4 : 0));
234    }
235
236    /**
237     * Gets the create time as a {@link FileTime} of this ZIP entry, or null if no such timestamp exists in the ZIP entry. The milliseconds are always zeroed
238     * out, since the underlying data offers only per-second precision.
239     *
240     * @return modify time as {@link FileTime} or null.
241     * @since 1.23
242     */
243    public FileTime getCreateFileTime() {
244        return unixTimeToFileTime(createTime);
245    }
246
247    /**
248     * <p>
249     * Gets the create time as a java.util.Date of this ZIP entry, or null if no such timestamp exists in the ZIP entry. The milliseconds are always zeroed out,
250     * since the underlying data offers only per-second precision.
251     * </p>
252     * <p>
253     * Note: modern Linux file systems (e.g., ext2) do not appear to store a "create time" value, and so it's usually omitted altogether in the ZIP extra field.
254     * Perhaps other Unix systems track this.
255     * </p>
256     *
257     * @return create time as java.util.Date or null.
258     */
259    public Date getCreateJavaTime() {
260        return zipLongToDate(createTime);
261    }
262
263    /**
264     * <p>
265     * Gets the create time (seconds since epoch) of this ZIP entry as a ZipLong object, or null if no such timestamp exists in the ZIP entry.
266     * </p>
267     * <p>
268     * Note: modern Linux file systems (e.g., ext2) do not appear to store a "create time" value, and so it's usually omitted altogether in the ZIP extra field.
269     * Perhaps other Unix systems track this.
270     * </p>
271     *
272     * @return create time (seconds since epoch) or null.
273     */
274    public ZipLong getCreateTime() {
275        return createTime;
276    }
277
278    /**
279     * Gets flags byte. The flags byte tells us which of the three datestamp fields are present in the data:
280     *
281     * <pre>
282     * bit0 - modify time
283     * bit1 - access time
284     * bit2 - create time
285     * </pre>
286     *
287     * Only first 3 bits of flags are used according to the latest version of the spec (December 2012).
288     *
289     * @return flags byte indicating which of the three datestamp fields are present.
290     */
291    public byte getFlags() {
292        return flags;
293    }
294
295    /**
296     * Gets the Header-ID.
297     *
298     * @return the value for the header id for this extrafield
299     */
300    @Override
301    public ZipShort getHeaderId() {
302        return HEADER_ID;
303    }
304
305    /**
306     * Gets the actual data to put into local file data - without Header-ID or length specifier.
307     *
308     * @return get the data
309     */
310    @Override
311    public byte[] getLocalFileDataData() {
312        final byte[] data = new byte[getLocalFileDataLength().getValue()];
313        int pos = 0;
314        data[pos++] = 0;
315        if (bit0_modifyTimePresent) {
316            data[0] |= MODIFY_TIME_BIT;
317            System.arraycopy(modifyTime.getBytes(), 0, data, pos, 4);
318            pos += 4;
319        }
320        if (bit1_accessTimePresent && accessTime != null) {
321            data[0] |= ACCESS_TIME_BIT;
322            System.arraycopy(accessTime.getBytes(), 0, data, pos, 4);
323            pos += 4;
324        }
325        if (bit2_createTimePresent && createTime != null) {
326            data[0] |= CREATE_TIME_BIT;
327            System.arraycopy(createTime.getBytes(), 0, data, pos, 4);
328            pos += 4; // NOSONAR - assignment as documentation
329        }
330        return data;
331    }
332
333    /**
334     * Gets the length of the extra field in the local file data - without Header-ID or length specifier.
335     *
336     * @return a {@code ZipShort} for the length of the data of this extra field
337     */
338    @Override
339    public ZipShort getLocalFileDataLength() {
340        return new ZipShort(1 + (bit0_modifyTimePresent ? 4 : 0) + (bit1_accessTimePresent && accessTime != null ? 4 : 0)
341                + (bit2_createTimePresent && createTime != null ? 4 : 0));
342    }
343
344    /**
345     * Gets the modify time as a {@link FileTime} of this ZIP entry, or null if no such timestamp exists in the ZIP entry. The milliseconds are always zeroed
346     * out, since the underlying data offers only per-second precision.
347     *
348     * @return modify time as {@link FileTime} or null.
349     * @since 1.23
350     */
351    public FileTime getModifyFileTime() {
352        return unixTimeToFileTime(modifyTime);
353    }
354
355    /**
356     * Gets the modify time as a java.util.Date of this ZIP entry, or null if no such timestamp exists in the ZIP entry. The milliseconds are always zeroed out,
357     * since the underlying data offers only per-second precision.
358     *
359     * @return modify time as java.util.Date or null.
360     */
361    public Date getModifyJavaTime() {
362        return zipLongToDate(modifyTime);
363    }
364
365    /**
366     * Gets the modify time (seconds since epoch) of this ZIP entry as a ZipLong object, or null if no such timestamp exists in the ZIP entry.
367     *
368     * @return modify time (seconds since epoch) or null.
369     */
370    public ZipLong getModifyTime() {
371        return modifyTime;
372    }
373
374    @Override
375    public int hashCode() {
376        int hc = -123 * (flags & 0x07); // only last 3 bits of flags matter
377        if (modifyTime != null) {
378            hc ^= modifyTime.hashCode();
379        }
380        if (accessTime != null) {
381            // Since accessTime is often same as modifyTime,
382            // this prevents them from XOR negating each other.
383            hc ^= Integer.rotateLeft(accessTime.hashCode(), 11);
384        }
385        if (createTime != null) {
386            hc ^= Integer.rotateLeft(createTime.hashCode(), 22);
387        }
388        return hc;
389    }
390
391    /**
392     * Tests whether bit0 of the flags byte is set or not, which should correspond to the presence or absence of a modify timestamp in this particular ZIP
393     * entry.
394     *
395     * @return true if bit0 of the flags byte is set.
396     */
397    public boolean isBit0_modifyTimePresent() {
398        return bit0_modifyTimePresent;
399    }
400
401    /**
402     * Tests whether bit1 of the flags byte is set or not, which should correspond to the presence or absence of a "last access" timestamp in this particular
403     * ZIP entry.
404     *
405     * @return true if bit1 of the flags byte is set.
406     */
407    public boolean isBit1_accessTimePresent() {
408        return bit1_accessTimePresent;
409    }
410
411    /**
412     * Tests whether bit2 of the flags byte is set or not, which should correspond to the presence or absence of a create timestamp in this particular ZIP
413     * entry.
414     *
415     * @return true if bit2 of the flags byte is set.
416     */
417    public boolean isBit2_createTimePresent() {
418        return bit2_createTimePresent;
419    }
420
421    /**
422     * Doesn't do anything special since this class always uses the same parsing logic for both central directory and local file data.
423     */
424    @Override
425    public void parseFromCentralDirectoryData(final byte[] buffer, final int offset, final int length) throws ZipException {
426        reset();
427        parseFromLocalFileData(buffer, offset, length);
428    }
429
430    /**
431     * Populate data from this array as if it was in local file data.
432     *
433     * @param data   an array of bytes
434     * @param offset the start offset
435     * @param length the number of bytes in the array from offset
436     * @throws java.util.zip.ZipException on error
437     */
438    @Override
439    public void parseFromLocalFileData(final byte[] data, int offset, final int length) throws ZipException {
440        reset();
441        if (length < 1) {
442            throw new ZipException("X5455_ExtendedTimestamp too short, only " + length + " bytes");
443        }
444        final int len = offset + length;
445        setFlags(data[offset++]);
446        if (bit0_modifyTimePresent && offset + 4 <= len) {
447            modifyTime = new ZipLong(data, offset);
448            offset += 4;
449        } else {
450            bit0_modifyTimePresent = false;
451        }
452        if (bit1_accessTimePresent && offset + 4 <= len) {
453            accessTime = new ZipLong(data, offset);
454            offset += 4;
455        } else {
456            bit1_accessTimePresent = false;
457        }
458        if (bit2_createTimePresent && offset + 4 <= len) {
459            createTime = new ZipLong(data, offset);
460            offset += 4; // NOSONAR - assignment as documentation
461        } else {
462            bit2_createTimePresent = false;
463        }
464    }
465
466    /**
467     * Reset state back to newly constructed state. Helps us make sure parse() calls always generate clean results.
468     */
469    private void reset() {
470        setFlags((byte) 0);
471        this.modifyTime = null;
472        this.accessTime = null;
473        this.createTime = null;
474    }
475
476    /**
477     * <p>
478     * Sets the acccess time as a {@link FileTime} of this ZIP entry. Supplied value is truncated to per-second precision (milliseconds zeroed-out).
479     * </p>
480     * <p>
481     * Note: the setters for flags and timestamps are decoupled. Even if the timestamp is not-null, it will only be written out if the corresponding bit in the
482     * flags is also set.
483     * </p>
484     *
485     * @param time access time as {@link FileTime}
486     * @since 1.23
487     */
488    public void setAccessFileTime(final FileTime time) {
489        setAccessTime(fileTimeToZipLong(time));
490    }
491
492    /**
493     * <p>
494     * Sets the access time as a java.util.Date of this ZIP entry. Supplied value is truncated to per-second precision (milliseconds zeroed-out).
495     * </p>
496     * <p>
497     * Note: the setters for flags and timestamps are decoupled. Even if the timestamp is not-null, it will only be written out if the corresponding bit in the
498     * flags is also set.
499     * </p>
500     *
501     * @param d access time as java.util.Date
502     */
503    public void setAccessJavaTime(final Date d) {
504        setAccessTime(dateToZipLong(d));
505    }
506
507    /**
508     * <p>
509     * Sets the access time (seconds since epoch) of this ZIP entry using a ZipLong object
510     * </p>
511     * <p>
512     * Note: the setters for flags and timestamps are decoupled. Even if the timestamp is not-null, it will only be written out if the corresponding bit in the
513     * flags is also set.
514     * </p>
515     *
516     * @param l ZipLong of the access time (seconds per epoch)
517     */
518    public void setAccessTime(final ZipLong l) {
519        bit1_accessTimePresent = l != null;
520        flags = (byte) (l != null ? flags | ACCESS_TIME_BIT : flags & ~ACCESS_TIME_BIT);
521        this.accessTime = l;
522    }
523
524    /**
525     * <p>
526     * Sets the create time as a {@link FileTime} of this ZIP entry. Supplied value is truncated to per-second precision (milliseconds zeroed-out).
527     * </p>
528     * <p>
529     * Note: the setters for flags and timestamps are decoupled. Even if the timestamp is not-null, it will only be written out if the corresponding bit in the
530     * flags is also set.
531     * </p>
532     *
533     * @param time create time as {@link FileTime}
534     * @since 1.23
535     */
536    public void setCreateFileTime(final FileTime time) {
537        setCreateTime(fileTimeToZipLong(time));
538    }
539
540    /**
541     * <p>
542     * Sets the create time as a java.util.Date of this ZIP entry. Supplied value is truncated to per-second precision (milliseconds zeroed-out).
543     * </p>
544     * <p>
545     * Note: the setters for flags and timestamps are decoupled. Even if the timestamp is not-null, it will only be written out if the corresponding bit in the
546     * flags is also set.
547     * </p>
548     *
549     * @param d create time as java.util.Date
550     */
551    public void setCreateJavaTime(final Date d) {
552        setCreateTime(dateToZipLong(d));
553    }
554
555    /**
556     * <p>
557     * Sets the create time (seconds since epoch) of this ZIP entry using a ZipLong object
558     * </p>
559     * <p>
560     * Note: the setters for flags and timestamps are decoupled. Even if the timestamp is not-null, it will only be written out if the corresponding bit in the
561     * flags is also set.
562     * </p>
563     *
564     * @param l ZipLong of the create time (seconds per epoch)
565     */
566    public void setCreateTime(final ZipLong l) {
567        bit2_createTimePresent = l != null;
568        flags = (byte) (l != null ? flags | CREATE_TIME_BIT : flags & ~CREATE_TIME_BIT);
569        this.createTime = l;
570    }
571
572    /**
573     * Sets flags byte. The flags byte tells us which of the three datestamp fields are present in the data:
574     *
575     * <pre>
576     * bit0 - modify time
577     * bit1 - access time
578     * bit2 - create time
579     * </pre>
580     *
581     * Only first 3 bits of flags are used according to the latest version of the spec (December 2012).
582     *
583     * @param flags flags byte indicating which of the three datestamp fields are present.
584     */
585    public void setFlags(final byte flags) {
586        this.flags = flags;
587        this.bit0_modifyTimePresent = (flags & MODIFY_TIME_BIT) == MODIFY_TIME_BIT;
588        this.bit1_accessTimePresent = (flags & ACCESS_TIME_BIT) == ACCESS_TIME_BIT;
589        this.bit2_createTimePresent = (flags & CREATE_TIME_BIT) == CREATE_TIME_BIT;
590    }
591
592    /**
593     * <p>
594     * Sets the modify time as a {@link FileTime} of this ZIP entry. Supplied value is truncated to per-second precision (milliseconds zeroed-out).
595     * </p>
596     * <p>
597     * Note: the setters for flags and timestamps are decoupled. Even if the timestamp is not-null, it will only be written out if the corresponding bit in the
598     * flags is also set.
599     * </p>
600     *
601     * @param time modify time as {@link FileTime}
602     * @since 1.23
603     */
604    public void setModifyFileTime(final FileTime time) {
605        setModifyTime(fileTimeToZipLong(time));
606    }
607
608    /**
609     * <p>
610     * Sets the modify time as a java.util.Date of this ZIP entry. Supplied value is truncated to per-second precision (milliseconds zeroed-out).
611     * </p>
612     * <p>
613     * Note: the setters for flags and timestamps are decoupled. Even if the timestamp is not-null, it will only be written out if the corresponding bit in the
614     * flags is also set.
615     * </p>
616     *
617     * @param d modify time as java.util.Date
618     */
619    public void setModifyJavaTime(final Date d) {
620        setModifyTime(dateToZipLong(d));
621    }
622
623    /**
624     * <p>
625     * Sets the modify time (seconds since epoch) of this ZIP entry using a ZipLong object.
626     * </p>
627     * <p>
628     * Note: the setters for flags and timestamps are decoupled. Even if the timestamp is not-null, it will only be written out if the corresponding bit in the
629     * flags is also set.
630     * </p>
631     *
632     * @param l ZipLong of the modify time (seconds per epoch)
633     */
634    public void setModifyTime(final ZipLong l) {
635        bit0_modifyTimePresent = l != null;
636        flags = (byte) (l != null ? flags | MODIFY_TIME_BIT : flags & ~MODIFY_TIME_BIT);
637        this.modifyTime = l;
638    }
639
640    /**
641     * Returns a String representation of this class useful for debugging purposes.
642     *
643     * @return A String representation of this class useful for debugging purposes.
644     */
645    @Override
646    public String toString() {
647        final StringBuilder buf = new StringBuilder();
648        buf.append("0x5455 Zip Extra Field: Flags=");
649        buf.append(Integer.toBinaryString(ZipUtil.unsignedIntToSignedByte(flags))).append(" ");
650        if (bit0_modifyTimePresent && modifyTime != null) {
651            final Date m = getModifyJavaTime();
652            buf.append(" Modify:[").append(m).append("] ");
653        }
654        if (bit1_accessTimePresent && accessTime != null) {
655            final Date a = getAccessJavaTime();
656            buf.append(" Access:[").append(a).append("] ");
657        }
658        if (bit2_createTimePresent && createTime != null) {
659            final Date c = getCreateJavaTime();
660            buf.append(" Create:[").append(c).append("] ");
661        }
662        return buf.toString();
663    }
664
665}