/* * 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.tools.zip; import java.util.zip.CRC32; import java.util.zip.ZipException; /** * Adds Unix file permission and UID/GID fields as well as symbolic link * handling. * *
* This class uses the ASi extra field in the format: * *
* Value Size Description * ----- ---- ----------- * (Unix3) 0x756e Short tag for this extra block type * TSize Short total data size for this block * CRC Long CRC-32 of the remaining data * Mode Short file permissions * SizDev Long symlink'd size OR major/minor dev num * UID Short user ID * GID Short group ID * (var.) variable symbolic link filename ** * taken from appnote.iz (Info-ZIP note, 981119) found at ftp://ftp.uu.net/pub/archiving/zip/doc/ * * * *
* Short is two bytes and Long is four bytes in big endian byte and word order, * device numbers are currently not supported. *
* */ public class AsiExtraField implements ZipExtraField, UnixStat, Cloneable { private static final ZipShort HEADER_ID = new ZipShort(0x756E); /** * Standard Unix stat(2) file mode. * * @since 1.1 */ private int mode = 0; /** * User ID. * * @since 1.1 */ private int uid = 0; /** * Group ID. * * @since 1.1 */ private int gid = 0; /** * File this entry points to, if it is a symbolic link. * ** empty string - if entry is not a symbolic link. *
* * @since 1.1 */ private String link = ""; /** * Is this an entry for a directory? * * @since 1.1 */ private boolean dirFlag = false; /** * Instance used to calculate checksums. * * @since 1.1 */ private CRC32 crc = new CRC32(); /** Constructor for AsiExtraField. */ public AsiExtraField() { } /** * The Header-ID. * * @return the value for the header id for this extrafield * @since 1.1 */ public ZipShort getHeaderId() { return HEADER_ID; } /** * Length of the extra field in the local file data - without Header-ID or * length specifier. * * @return aZipShort
for the length of the data of this extra
* field
* @since 1.1
*/
public ZipShort getLocalFileDataLength() {
return new ZipShort(4 // CRC
+ 2 // Mode
+ 4 // SizDev
+ 2 // UID
+ 2 // GID
+ getLinkedFile().getBytes().length);
}
/**
* Delegate to local file data.
*
* @return the centralDirectory length
* @since 1.1
*/
public ZipShort getCentralDirectoryLength() {
return getLocalFileDataLength();
}
/**
* The actual data to put into local file data - without Header-ID or length
* specifier.
*
* @return get the data
* @since 1.1
*/
public byte[] getLocalFileDataData() {
// CRC will be added later
byte[] data = new byte[getLocalFileDataLength().getValue() - 4];
System.arraycopy(ZipShort.getBytes(getMode()), 0, data, 0, 2);
byte[] linkArray = getLinkedFile().getBytes();
System.arraycopy(ZipLong.getBytes(linkArray.length), 0, data, 2, 4);
System.arraycopy(ZipShort.getBytes(getUserId()), 0, data, 6, 2);
System.arraycopy(ZipShort.getBytes(getGroupId()), 0, data, 8, 2);
System.arraycopy(linkArray, 0, data, 10, linkArray.length);
crc.reset();
crc.update(data);
long checksum = crc.getValue();
byte[] result = new byte[data.length + 4];
System.arraycopy(ZipLong.getBytes(checksum), 0, result, 0, 4);
System.arraycopy(data, 0, result, 4, data.length);
return result;
}
/**
* Delegate to local file data.
*
* @return the local file data
* @since 1.1
*/
public byte[] getCentralDirectoryData() {
return getLocalFileDataData();
}
/**
* Set the user id.
*
* @param uid
* the user id
* @since 1.1
*/
public void setUserId(int uid) {
this.uid = uid;
}
/**
* Get the user id.
*
* @return the user id
* @since 1.1
*/
public int getUserId() {
return uid;
}
/**
* Set the group id.
*
* @param gid
* the group id
* @since 1.1
*/
public void setGroupId(int gid) {
this.gid = gid;
}
/**
* Get the group id.
*
* @return the group id
* @since 1.1
*/
public int getGroupId() {
return gid;
}
/**
* Indicate that this entry is a symbolic link to the given filename.
*
* @param name
* Name of the file this entry links to, empty String if it is not a
* symbolic link.
*
* @since 1.1
*/
public void setLinkedFile(String name) {
link = name;
mode = getMode(mode);
}
/**
* Name of linked file
*
* @return name of the file this entry links to if it is a symbolic link, the
* empty string otherwise.
*
* @since 1.1
*/
public String getLinkedFile() {
return link;
}
/**
* Is this entry a symbolic link?
*
* @return true if this is a symbolic link
* @since 1.1
*/
public boolean isLink() {
return getLinkedFile().length() != 0;
}
/**
* File mode of this file.
*
* @param mode
* the file mode
* @since 1.1
*/
public void setMode(int mode) {
this.mode = getMode(mode);
}
/**
* File mode of this file.
*
* @return the file mode
* @since 1.1
*/
public int getMode() {
return mode;
}
/**
* Indicate whether this entry is a directory.
*
* @param dirFlag
* if true, this entry is a directory
* @since 1.1
*/
public void setDirectory(boolean dirFlag) {
this.dirFlag = dirFlag;
mode = getMode(mode);
}
/**
* Is this entry a directory?
*
* @return true if this entry is a directory
* @since 1.1
*/
public boolean isDirectory() {
return dirFlag && !isLink();
}
/**
* 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
* @since 1.1
* @throws ZipException
* on error
*/
public void parseFromLocalFileData(byte[] data, int offset, int length)
throws ZipException {
long givenChecksum = ZipLong.getValue(data, offset);
byte[] tmp = new byte[length - 4];
System.arraycopy(data, offset + 4, tmp, 0, length - 4);
crc.reset();
crc.update(tmp);
long realChecksum = crc.getValue();
if (givenChecksum != realChecksum) {
throw new ZipException("bad CRC checksum "
+ Long.toHexString(givenChecksum) + " instead of "
+ Long.toHexString(realChecksum));
}
int newMode = ZipShort.getValue(tmp, 0);
byte[] linkArray = new byte[(int) ZipLong.getValue(tmp, 2)];
uid = ZipShort.getValue(tmp, 6);
gid = ZipShort.getValue(tmp, 8);
if (linkArray.length == 0) {
link = "";
} else {
System.arraycopy(tmp, 10, linkArray, 0, linkArray.length);
link = new String(linkArray);
}
setDirectory((newMode & DIR_FLAG) != 0);
setMode(newMode);
}
/**
* Get the file mode for given permissions with the correct file type.
*
* @param mode
* the mode
* @return the type with the mode
* @since 1.1
*/
protected int getMode(int mode) {
int type = FILE_FLAG;
if (isLink()) {
type = LINK_FLAG;
} else if (isDirectory()) {
type = DIR_FLAG;
}
return type | (mode & PERM_MASK);
}
}