/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.commons.compress.archivers.zip;
import java.io.Serializable;
import java.util.Date;
import java.util.zip.ZipException;
/**
* <p>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, create*). The timestamps are stored as 32 bit unsigned
* integers representing seconds since UNIX epoch (Jan 1st, 1970, UTC).
* This field improves on zip's default timestamp granularity, since it
* allows one to store additional timestamps, and, in addition, the timestamps
* are stored using per-second granularity (zip's default behaviour can only store
* timestamps to the nearest <em>even</em> second).
* </p><p>
* Unfortunately, 32 (unsigned) bits can only store dates up to the year 2106,
* and so this extra field will eventually be obsolete. Enjoy it while it lasts!
* </p>
* <ul>
* <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>
* <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 value
* using the NOATIME mount option to optimize disk behaviour,
* and thus it's not always reliable. In those cases
* it's always equal to modifyTime.
* </li>
* <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 the zip extra
* field. Perhaps other unix systems track this.
* </li></ul>
* <p>
* We're using the field definition given in Info-Zip's source archive:
* zip-3.0.tar.gz/proginfo/extrafld.txt
* </p>
* <pre>
* Value Size Description
* ----- ---- -----------
* 0x5455 Short tag for this extra block type ("UT")
* TSize Short total data size for this block
* Flags Byte info bits
* (ModTime) Long time of last modification (UTC/GMT)
* (AcTime) Long time of last access (UTC/GMT)
* (CrTime) Long time of original creation (UTC/GMT)
*
* Central-header version:
*
* Value Size Description
* ----- ---- -----------
* 0x5455 Short tag for this extra block type ("UT")
* TSize Short total data size for this block
* Flags Byte info bits (refers to local header!)
* (ModTime) Long time of last modification (UTC/GMT)
* </pre>
* @since 1.5
*/
public class X5455_ExtendedTimestamp implements ZipExtraField, Cloneable, Serializable {
private static final ZipShort HEADER_ID = new ZipShort(0x5455);
private static final long serialVersionUID = 1L;
/**
* The bit set inside the flags by when the last modification time
* is present in this extra field.
*/
public static final byte MODIFY_TIME_BIT = 1;
/**
* The bit set inside the flags by when the lasr access time is
* present in this extra field.
*/
public static final byte ACCESS_TIME_BIT = 2;
/**
* The bit set inside the flags by when the original creation time
* is present in this extra field.
*/
public static final byte CREATE_TIME_BIT = 4;
// The 3 boolean fields (below) come from this flags byte. The remaining 5 bits
// are ignored according to the current version of the spec (December 2012).
private byte flags;
// Note: even if bit1 and bit2 are set, the Central data will still not contain
// access/create fields: only local data ever holds those! This causes
// some of our implementation to look a little odd, with seemingly spurious
// != null and length checks.
private boolean bit0_modifyTimePresent;
private boolean bit1_accessTimePresent;
private boolean bit2_createTimePresent;
private ZipLong modifyTime;
private ZipLong accessTime;
private ZipLong createTime;
/**
* Constructor for X5455_ExtendedTimestamp.
*/
public X5455_ExtendedTimestamp() {}
/**
* The Header-ID.
*
* @return the value for the header id for this extrafield
*/
@Override
public ZipShort getHeaderId() {
return HEADER_ID;
}
/**
* Length of the extra field in the local file data - without
* Header-ID or length specifier.
*
* @return a <code>ZipShort</code> for the length of the data of this extra field
*/
@Override
public ZipShort getLocalFileDataLength() {
return new ZipShort(1 +
(bit0_modifyTimePresent ? 4 : 0) +
(bit1_accessTimePresent && accessTime != null ? 4 : 0) +
(bit2_createTimePresent && createTime != null ? 4 : 0)
);
}
/**
* Length of the extra field in the local file data - without
* Header-ID or length specifier.
*
* <p>For X5455 the central length is often smaller than the
* local length, because central cannot contain access or create
* timestamps.</p>
*
* @return a <code>ZipShort</code> for the length of the data of this extra field
*/
@Override
public ZipShort getCentralDirectoryLength() {
return new ZipShort(1 +
(bit0_modifyTimePresent ? 4 : 0)
);
}
/**
* The actual data to put into local file data - without Header-ID
* or length specifier.
*
* @return get the data
*/
@Override
public byte[] getLocalFileDataData() {
final byte[] data = new byte[getLocalFileDataLength().getValue()];
int pos = 0;
data[pos++] = 0;
if (bit0_modifyTimePresent) {
data[0] |= MODIFY_TIME_BIT;
System.arraycopy(modifyTime.getBytes(), 0, data, pos, 4);
pos += 4;
}
if (bit1_accessTimePresent && accessTime != null) {
data[0] |= ACCESS_TIME_BIT;
System.arraycopy(accessTime.getBytes(), 0, data, pos, 4);
pos += 4;
}
if (bit2_createTimePresent && createTime != null) {
data[0] |= CREATE_TIME_BIT;
System.arraycopy(createTime.getBytes(), 0, data, pos, 4);
pos += 4;
}
return data;
}
/**
* The actual data to put into central directory data - without Header-ID
* or length specifier.
*
* @return the central directory data
*/
@Override
public byte[] getCentralDirectoryData() {
final byte[] centralData = new byte[getCentralDirectoryLength().getValue()];
final byte[] localData = getLocalFileDataData();
// Truncate out create & access time (last 8 bytes) from
// the copy of the local data we obtained:
System.arraycopy(localData, 0, centralData, 0, centralData.length);
return centralData;
}
/**
* Populate data from this array as if it was in local file data.
*
* @param data an array of bytes
* @param offset the start offset
* @param length the number of bytes in the array from offset
* @throws java.util.zip.ZipException on error
*/
@Override
public void parseFromLocalFileData(
final byte[] data, int offset, final int length
) throws ZipException {
reset();
final int len = offset + length;
setFlags(data[offset++]);
if (bit0_modifyTimePresent) {
modifyTime = new ZipLong(data, offset);
offset += 4;
}
// Notice the extra length check in case we are parsing the shorter
// central data field (for both access and create timestamps).
if (bit1_accessTimePresent && offset + 4 <= len) {
accessTime = new ZipLong(data, offset);
offset += 4;
}
if (bit2_createTimePresent && offset + 4 <= len) {
createTime = new ZipLong(data, offset);
offset += 4;
}
}
/**
* Doesn't do anything special since this class always uses the
* same parsing logic for both central directory and local file data.
*/
@Override
public void parseFromCentralDirectoryData(
final byte[] buffer, final int offset, final int length
) throws ZipException {
reset();
parseFromLocalFileData(buffer, offset, length);
}
/**
* Reset state back to newly constructed state. Helps us make sure
* parse() calls always generate clean results.
*/
private void reset() {
setFlags((byte) 0);
this.modifyTime = null;
this.accessTime = null;
this.createTime = null;
}
/**
* Sets flags byte. The flags byte tells us which of the
* three datestamp fields are present in the data:
* <pre>
* bit0 - modify time
* bit1 - access time
* bit2 - create time
* </pre>
* Only first 3 bits of flags are used according to the
* latest version of the spec (December 2012).
*
* @param flags flags byte indicating which of the
* three datestamp fields are present.
*/
public void setFlags(final byte flags) {
this.flags = flags;
this.bit0_modifyTimePresent = (flags & MODIFY_TIME_BIT) == MODIFY_TIME_BIT;
this.bit1_accessTimePresent = (flags & ACCESS_TIME_BIT) == ACCESS_TIME_BIT;
this.bit2_createTimePresent = (flags & CREATE_TIME_BIT) == CREATE_TIME_BIT;
}
/**
* Gets flags byte. The flags byte tells us which of the
* three datestamp fields are present in the data:
* <pre>
* bit0 - modify time
* bit1 - access time
* bit2 - create time
* </pre>
* Only first 3 bits of flags are used according to the
* latest version of the spec (December 2012).
*
* @return flags byte indicating which of the
* three datestamp fields are present.
*/
public byte getFlags() { return flags; }
/**
* Returns 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 entry.
*
* @return true if bit0 of the flags byte is set.
*/
public boolean isBit0_modifyTimePresent() { return bit0_modifyTimePresent; }
/**
* Returns 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 zip entry.
*
* @return true if bit1 of the flags byte is set.
*/
public boolean isBit1_accessTimePresent() { return bit1_accessTimePresent; }
/**
* Returns 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 entry.
*
* @return true if bit2 of the flags byte is set.
*/
public boolean isBit2_createTimePresent() { return bit2_createTimePresent; }
/**
* Returns 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.
*
* @return modify time (seconds since epoch) or null.
*/
public ZipLong getModifyTime() { return modifyTime; }
/**
* Returns 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.
*
* @return access time (seconds since epoch) or null.
*/
public ZipLong getAccessTime() { return accessTime; }
/**
* <p>
* Returns 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.
* </p><p>
* 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. Perhaps other unix systems track this.
*
* @return create time (seconds since epoch) or null.
*/
public ZipLong getCreateTime() { return createTime; }
/**
* Returns 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, since the underlying data
* offers only per-second precision.
*
* @return modify time as java.util.Date or null.
*/
public Date getModifyJavaTime() {
return modifyTime != null ? new Date(modifyTime.getValue() * 1000) : null;
}
/**
* Returns 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, since the underlying data
* offers only per-second precision.
*
* @return access time as java.util.Date or null.
*/
public Date getAccessJavaTime() {
return accessTime != null ? new Date(accessTime.getValue() * 1000) : null;
}
/**
* <p>
* Returns the create time as a 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, since the underlying data
* offers only per-second precision.
* </p><p>
* 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. Perhaps other unix systems track this.
*
* @return create time as java.util.Date or null.
*/
public Date getCreateJavaTime() {
return createTime != null ? new Date(createTime.getValue() * 1000) : null;
}
/**
* <p>
* Sets the modify time (seconds since epoch) of this zip entry
* using a ZipLong object.
* </p><p>
* 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 flags is also set.
* </p>
*
* @param l ZipLong of the modify time (seconds per epoch)
*/
public void setModifyTime(final ZipLong l) {
bit0_modifyTimePresent = l != null;
flags = (byte) (l != null ? (flags | MODIFY_TIME_BIT)
: (flags & ~MODIFY_TIME_BIT));
this.modifyTime = l;
}
/**
* <p>
* Sets the access time (seconds since epoch) of this zip entry
* using a ZipLong object
* </p><p>
* 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 flags is also set.
* </p>
*
* @param l ZipLong of the access time (seconds per epoch)
*/
public void setAccessTime(final ZipLong l) {
bit1_accessTimePresent = l != null;
flags = (byte) (l != null ? (flags | ACCESS_TIME_BIT)
: (flags & ~ACCESS_TIME_BIT));
this.accessTime = l;
}
/**
* <p>
* Sets the create time (seconds since epoch) of this zip entry
* using a ZipLong object
* </p><p>
* 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 flags is also set.
* </p>
*
* @param l ZipLong of the create time (seconds per epoch)
*/
public void setCreateTime(final ZipLong l) {
bit2_createTimePresent = l != null;
flags = (byte) (l != null ? (flags | CREATE_TIME_BIT)
: (flags & ~CREATE_TIME_BIT));
this.createTime = l;
}
/**
* <p>
* Sets the modify time as a java.util.Date
* of this zip entry. Supplied value is truncated to per-second
* precision (milliseconds zeroed-out).
* </p><p>
* 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 flags is also set.
* </p>
*
* @param d modify time as java.util.Date
*/
public void setModifyJavaTime(final Date d) { setModifyTime(dateToZipLong(d)); }
/**
* <p>
* Sets the access time as a java.util.Date
* of this zip entry. Supplied value is truncated to per-second
* precision (milliseconds zeroed-out).
* </p><p>
* 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 flags is also set.
* </p>
*
* @param d access time as java.util.Date
*/
public void setAccessJavaTime(final Date d) { setAccessTime(dateToZipLong(d)); }
/**
* <p>
* Sets the create time as a java.util.Date
* of this zip entry. Supplied value is truncated to per-second
* precision (milliseconds zeroed-out).
* </p><p>
* 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 flags is also set.
* </p>
*
* @param d create time as java.util.Date
*/
public void setCreateJavaTime(final Date d) { setCreateTime(dateToZipLong(d)); }
/**
* Utility method converts java.util.Date (milliseconds since epoch)
* into a ZipLong (seconds since epoch).
* <p/>
* Also makes sure the converted ZipLong is not too big to fit
* in 32 unsigned bits.
*
* @param d java.util.Date to convert to ZipLong
* @return ZipLong
*/
private static ZipLong dateToZipLong(final Date d) {
if (d == null) { return null; }
final long TWO_TO_32 = 0x100000000L;
final long l = d.getTime() / 1000;
if (l >= TWO_TO_32) {
throw new IllegalArgumentException("Cannot set an X5455 timestamp larger than 2^32: " + l);
}
return new ZipLong(l);
}
/**
* Returns a String representation of this class useful for
* debugging purposes.
*
* @return A String representation of this class useful for
* debugging purposes.
*/
@Override
public String toString() {
final StringBuilder buf = new StringBuilder();
buf.append("0x5455 Zip Extra Field: Flags=");
buf.append(Integer.toBinaryString(ZipUtil.unsignedIntToSignedByte(flags))).append(" ");
if (bit0_modifyTimePresent && modifyTime != null) {
final Date m = getModifyJavaTime();
buf.append(" Modify:[").append(m).append("] ");
}
if (bit1_accessTimePresent && accessTime != null) {
final Date a = getAccessJavaTime();
buf.append(" Access:[").append(a).append("] ");
}
if (bit2_createTimePresent && createTime != null) {
final Date c = getCreateJavaTime();
buf.append(" Create:[").append(c).append("] ");
}
return buf.toString();
}
@Override
public Object clone() throws CloneNotSupportedException {
return super.clone();
}
@Override
public boolean equals(final Object o) {
if (o instanceof X5455_ExtendedTimestamp) {
final X5455_ExtendedTimestamp xf = (X5455_ExtendedTimestamp) o;
// The ZipLong==ZipLong clauses handle the cases where both are null.
// and only last 3 bits of flags matter.
return ((flags & 0x07) == (xf.flags & 0x07)) &&
(modifyTime == xf.modifyTime || (modifyTime != null && modifyTime.equals(xf.modifyTime))) &&
(accessTime == xf.accessTime || (accessTime != null && accessTime.equals(xf.accessTime))) &&
(createTime == xf.createTime || (createTime != null && createTime.equals(xf.createTime)));
}
return false;
}
@Override
public int hashCode() {
int hc = (-123 * (flags & 0x07)); // only last 3 bits of flags matter
if (modifyTime != null) {
hc ^= modifyTime.hashCode();
}
if (accessTime != null) {
// Since accessTime is often same as modifyTime,
// this prevents them from XOR negating each other.
hc ^= Integer.rotateLeft(accessTime.hashCode(), 11);
}
if (createTime != null) {
hc ^= Integer.rotateLeft(createTime.hashCode(), 22);
}
return hc;
}
}