src/main/java/org/apache/commons/compress/archivers/zip/AsiExtraField.java - platform/external/apache-commons-compress - Git at Google

 /*
  * 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.util.zip.CRC32;
 import java.util.zip.ZipException;

 /**
  * Adds Unix file permission and UID/GID fields as well as symbolic
  * link handling.
  *
  * <p>This class uses the ASi extra field in the format:</p>
  * <pre>
  *         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
  * </pre>
  * <p>taken from appnote.iz (Info-ZIP note, 981119) found at <a
  * href="ftp://ftp.uu.net/pub/archiving/zip/doc/">ftp://ftp.uu.net/pub/archiving/zip/doc/</a></p>
  *
  * <p>Short is two bytes and Long is four bytes in big endian byte and
  * word order, device numbers are currently not supported.</p>
  * @NotThreadSafe
  *
  * <p>Since the documentation this class is based upon doesn't mention
  * the character encoding of the file name at all, it is assumed that
  * it uses the current platform's default encoding.</p>
  */
 public class AsiExtraField implements ZipExtraField, UnixStat, Cloneable {

     private static final ZipShort HEADER_ID = new ZipShort(0x756E);
     private static final int      WORD = 4;
     /**
      * Standard Unix stat(2) file mode.
      */
     private int mode = 0;
     /**
      * User ID.
      */
     private int uid = 0;
     /**
      * Group ID.
      */
     private int gid = 0;
     /**
      * File this entry points to, if it is a symbolic link.
      *
      * <p>empty string - if entry is not a symbolic link.</p>
      */
     private String link = "";
     /**
      * Is this an entry for a directory?
      */
     private boolean dirFlag = false;

     /**
      * Instance used to calculate checksums.
      */
     private CRC32 crc = new CRC32();

     /** Constructor for AsiExtraField. */
     public AsiExtraField() {
     }

     /**
      * 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(WORD         // CRC
                           + 2         // Mode
                           + WORD         // SizDev
                           + 2         // UID
                           + 2         // GID
                           + getLinkedFile().getBytes().length);
                           // Uses default charset - see class Javadoc
     }

     /**
      * Delegate to local file data.
      * @return the centralDirectory length
      */
     @Override
     public ZipShort getCentralDirectoryLength() {
         return getLocalFileDataLength();
     }

     /**
      * The actual data to put into local file data - without Header-ID
      * or length specifier.
      * @return get the data
      */
     @Override
     public byte[] getLocalFileDataData() {
         // CRC will be added later
         final byte[] data = new byte[getLocalFileDataLength().getValue() - WORD];
         System.arraycopy(ZipShort.getBytes(getMode()), 0, data, 0, 2);

         final byte[] linkArray = getLinkedFile().getBytes(); // Uses default charset - see class Javadoc
         // CheckStyle:MagicNumber OFF
         System.arraycopy(ZipLong.getBytes(linkArray.length),
                          0, data, 2, WORD);

         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);
         // CheckStyle:MagicNumber ON

         crc.reset();
         crc.update(data);
         final long checksum = crc.getValue();

         final byte[] result = new byte[data.length + WORD];
         System.arraycopy(ZipLong.getBytes(checksum), 0, result, 0, WORD);
         System.arraycopy(data, 0, result, WORD, data.length);
         return result;
     }

     /**
      * Delegate to local file data.
      * @return the local file data
      */
     @Override
     public byte[] getCentralDirectoryData() {
         return getLocalFileDataData();
     }

     /**
      * Set the user id.
      * @param uid the user id
      */
     public void setUserId(final int uid) {
         this.uid = uid;
     }

     /**
      * Get the user id.
      * @return the user id
      */
     public int getUserId() {
         return uid;
     }

     /**
      * Set the group id.
      * @param gid the group id
      */
     public void setGroupId(final int gid) {
         this.gid = gid;
     }

     /**
      * Get the group id.
      * @return the group id
      */
     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.
      */
     public void setLinkedFile(final 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.
      */
     public String getLinkedFile() {
         return link;
     }

     /**
      * Is this entry a symbolic link?
      * @return true if this is a symbolic link
      */
     public boolean isLink() {
         return getLinkedFile().length() != 0;
     }

     /**
      * File mode of this file.
      * @param mode the file mode
      */
     public void setMode(final int mode) {
         this.mode = getMode(mode);
     }

     /**
      * File mode of this file.
      * @return the file mode
      */
     public int getMode() {
         return mode;
     }

     /**
      * Indicate whether this entry is a directory.
      * @param dirFlag if true, this entry is a directory
      */
     public void setDirectory(final boolean dirFlag) {
         this.dirFlag = dirFlag;
         mode = getMode(mode);
     }

     /**
      * Is this entry a directory?
      * @return true if this entry is a directory
      */
     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
      * @throws ZipException on error
      */
     @Override
     public void parseFromLocalFileData(final byte[] data, final int offset, final int length)
         throws ZipException {

         final long givenChecksum = ZipLong.getValue(data, offset);
         final byte[] tmp = new byte[length - WORD];
         System.arraycopy(data, offset + WORD, tmp, 0, length - WORD);
         crc.reset();
         crc.update(tmp);
         final long realChecksum = crc.getValue();
         if (givenChecksum != realChecksum) {
             throw new ZipException("bad CRC checksum "
                                    + Long.toHexString(givenChecksum)
                                    + " instead of "
                                    + Long.toHexString(realChecksum));
         }

         final int newMode = ZipShort.getValue(tmp, 0);
         // CheckStyle:MagicNumber OFF
         final 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); // Uses default charset - see class Javadoc
         }
         // CheckStyle:MagicNumber ON
         setDirectory((newMode & DIR_FLAG) != 0);
         setMode(newMode);
     }

     /**
      * Doesn't do anything special since this class always uses the
      * same data in central directory and local file data.
      */
     @Override
     public void parseFromCentralDirectoryData(final byte[] buffer, final int offset,
                                               final int length)
         throws ZipException {
         parseFromLocalFileData(buffer, offset, length);
     }

     /**
      * Get the file mode for given permissions with the correct file type.
      * @param mode the mode
      * @return the type with the mode
      */
     protected int getMode(final int mode) {
         int type = FILE_FLAG;
         if (isLink()) {
             type = LINK_FLAG;
         } else if (isDirectory()) {
             type = DIR_FLAG;
         }
         return type | (mode & PERM_MASK);
     }

     @Override
     public Object clone() {
         try {
             final AsiExtraField cloned = (AsiExtraField) super.clone();
             cloned.crc = new CRC32();
             return cloned;
         } catch (final CloneNotSupportedException cnfe) {
             // impossible
             throw new RuntimeException(cnfe); //NOSONAR
         }
     }
 }
	/*
	* 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.util.zip.CRC32;
	import java.util.zip.ZipException;

	/**
	* Adds Unix file permission and UID/GID fields as well as symbolic
	* link handling.
	*
	* <p>This class uses the ASi extra field in the format:</p>
	* <pre>
	* 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
	* </pre>
	* <p>taken from appnote.iz (Info-ZIP note, 981119) found at <a
	* href="ftp://ftp.uu.net/pub/archiving/zip/doc/">ftp://ftp.uu.net/pub/archiving/zip/doc/</a></p>
	*
	* <p>Short is two bytes and Long is four bytes in big endian byte and
	* word order, device numbers are currently not supported.</p>
	* @NotThreadSafe
	*
	* <p>Since the documentation this class is based upon doesn't mention
	* the character encoding of the file name at all, it is assumed that
	* it uses the current platform's default encoding.</p>
	*/
	public class AsiExtraField implements ZipExtraField, UnixStat, Cloneable {

	private static final ZipShort HEADER_ID = new ZipShort(0x756E);
	private static final int WORD = 4;
	/**
	* Standard Unix stat(2) file mode.
	*/
	private int mode = 0;
	/**
	* User ID.
	*/
	private int uid = 0;
	/**
	* Group ID.
	*/
	private int gid = 0;
	/**
	* File this entry points to, if it is a symbolic link.
	*
	* <p>empty string - if entry is not a symbolic link.</p>
	*/
	private String link = "";
	/**
	* Is this an entry for a directory?
	*/
	private boolean dirFlag = false;

	/**
	* Instance used to calculate checksums.
	*/
	private CRC32 crc = new CRC32();

	/** Constructor for AsiExtraField. */
	public AsiExtraField() {
	}

	/**
	* 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(WORD // CRC
	+ 2 // Mode
	+ WORD // SizDev
	+ 2 // UID
	+ 2 // GID
	+ getLinkedFile().getBytes().length);
	// Uses default charset - see class Javadoc
	}

	/**
	* Delegate to local file data.
	* @return the centralDirectory length
	*/
	@Override
	public ZipShort getCentralDirectoryLength() {
	return getLocalFileDataLength();
	}

	/**
	* The actual data to put into local file data - without Header-ID
	* or length specifier.
	* @return get the data
	*/
	@Override
	public byte[] getLocalFileDataData() {
	// CRC will be added later
	final byte[] data = new byte[getLocalFileDataLength().getValue() - WORD];
	System.arraycopy(ZipShort.getBytes(getMode()), 0, data, 0, 2);

	final byte[] linkArray = getLinkedFile().getBytes(); // Uses default charset - see class Javadoc
	// CheckStyle:MagicNumber OFF
	System.arraycopy(ZipLong.getBytes(linkArray.length),
	0, data, 2, WORD);

	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);
	// CheckStyle:MagicNumber ON

	crc.reset();
	crc.update(data);
	final long checksum = crc.getValue();

	final byte[] result = new byte[data.length + WORD];
	System.arraycopy(ZipLong.getBytes(checksum), 0, result, 0, WORD);
	System.arraycopy(data, 0, result, WORD, data.length);
	return result;
	}

	/**
	* Delegate to local file data.
	* @return the local file data
	*/
	@Override
	public byte[] getCentralDirectoryData() {
	return getLocalFileDataData();
	}

	/**
	* Set the user id.
	* @param uid the user id
	*/
	public void setUserId(final int uid) {
	this.uid = uid;
	}

	/**
	* Get the user id.
	* @return the user id
	*/
	public int getUserId() {
	return uid;
	}

	/**
	* Set the group id.
	* @param gid the group id
	*/
	public void setGroupId(final int gid) {
	this.gid = gid;
	}

	/**
	* Get the group id.
	* @return the group id
	*/
	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.
	*/
	public void setLinkedFile(final 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.
	*/
	public String getLinkedFile() {
	return link;
	}

	/**
	* Is this entry a symbolic link?
	* @return true if this is a symbolic link
	*/
	public boolean isLink() {
	return getLinkedFile().length() != 0;
	}

	/**
	* File mode of this file.
	* @param mode the file mode
	*/
	public void setMode(final int mode) {
	this.mode = getMode(mode);
	}

	/**
	* File mode of this file.
	* @return the file mode
	*/
	public int getMode() {
	return mode;
	}

	/**
	* Indicate whether this entry is a directory.
	* @param dirFlag if true, this entry is a directory
	*/
	public void setDirectory(final boolean dirFlag) {
	this.dirFlag = dirFlag;
	mode = getMode(mode);
	}

	/**
	* Is this entry a directory?
	* @return true if this entry is a directory
	*/
	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
	* @throws ZipException on error
	*/
	@Override
	public void parseFromLocalFileData(final byte[] data, final int offset, final int length)
	throws ZipException {

	final long givenChecksum = ZipLong.getValue(data, offset);
	final byte[] tmp = new byte[length - WORD];
	System.arraycopy(data, offset + WORD, tmp, 0, length - WORD);
	crc.reset();
	crc.update(tmp);
	final long realChecksum = crc.getValue();
	if (givenChecksum != realChecksum) {
	throw new ZipException("bad CRC checksum "
	+ Long.toHexString(givenChecksum)
	+ " instead of "
	+ Long.toHexString(realChecksum));
	}

	final int newMode = ZipShort.getValue(tmp, 0);
	// CheckStyle:MagicNumber OFF
	final 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); // Uses default charset - see class Javadoc
	}
	// CheckStyle:MagicNumber ON
	setDirectory((newMode & DIR_FLAG) != 0);
	setMode(newMode);
	}

	/**
	* Doesn't do anything special since this class always uses the
	* same data in central directory and local file data.
	*/
	@Override
	public void parseFromCentralDirectoryData(final byte[] buffer, final int offset,
	final int length)
	throws ZipException {
	parseFromLocalFileData(buffer, offset, length);
	}

	/**
	* Get the file mode for given permissions with the correct file type.
	* @param mode the mode
	* @return the type with the mode
	*/
	protected int getMode(final int mode) {
	int type = FILE_FLAG;
	if (isLink()) {
	type = LINK_FLAG;
	} else if (isDirectory()) {
	type = DIR_FLAG;
	}
	return type \| (mode & PERM_MASK);
	}

	@Override
	public Object clone() {
	try {
	final AsiExtraField cloned = (AsiExtraField) super.clone();
	cloned.crc = new CRC32();
	return cloned;
	} catch (final CloneNotSupportedException cnfe) {
	// impossible
	throw new RuntimeException(cnfe); //NOSONAR
	}
	}
	}