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.util.Arrays;
022
023/**
024 * Wrapper for extra field data that doesn't conform to the recommended format of header-tag + size + data.
025 *
026 * <p>The header-id is artificial (and not listed as a known ID in <a
027 * href="https://www.pkware.com/documents/casestudies/APPNOTE.TXT">APPNOTE.TXT</a>).  Since it isn't used anywhere
028 * except to satisfy the ZipExtraField contract it shouldn't matter anyway.</p>
029 *
030 * @since 1.1
031 * @NotThreadSafe
032 */
033public final class UnparseableExtraFieldData implements ZipExtraField {
034    private static final ZipShort HEADER_ID = new ZipShort(0xACC1);
035
036    private byte[] localFileData;
037    private byte[] centralDirectoryData;
038
039    /**
040     * The Header-ID.
041     *
042     * @return a completely arbitrary value that should be ignored.
043     */
044    @Override
045    public ZipShort getHeaderId() {
046        return HEADER_ID;
047    }
048
049    /**
050     * Length of the complete extra field in the local file data.
051     *
052     * @return The LocalFileDataLength value
053     */
054    @Override
055    public ZipShort getLocalFileDataLength() {
056        return new ZipShort(localFileData == null ? 0 : localFileData.length);
057    }
058
059    /**
060     * Length of the complete extra field in the central directory.
061     *
062     * @return The CentralDirectoryLength value
063     */
064    @Override
065    public ZipShort getCentralDirectoryLength() {
066        return centralDirectoryData == null
067            ? getLocalFileDataLength()
068            : new ZipShort(centralDirectoryData.length);
069    }
070
071    /**
072     * The actual data to put into local file data.
073     *
074     * @return The LocalFileDataData value
075     */
076    @Override
077    public byte[] getLocalFileDataData() {
078        return ZipUtil.copy(localFileData);
079    }
080
081    /**
082     * The actual data to put into central directory.
083     *
084     * @return The CentralDirectoryData value
085     */
086    @Override
087    public byte[] getCentralDirectoryData() {
088        return centralDirectoryData == null
089            ? getLocalFileDataData() : ZipUtil.copy(centralDirectoryData);
090    }
091
092    /**
093     * Populate data from this array as if it was in local file data.
094     *
095     * @param buffer the buffer to read data from
096     * @param offset offset into buffer to read data
097     * @param length the length of data
098     */
099    @Override
100    public void parseFromLocalFileData(final byte[] buffer, final int offset, final int length) {
101        localFileData = Arrays.copyOfRange(buffer, offset, offset + length);
102    }
103
104    /**
105     * Populate data from this array as if it was in central directory data.
106     *
107     * @param buffer the buffer to read data from
108     * @param offset offset into buffer to read data
109     * @param length the length of data
110     */
111    @Override
112    public void parseFromCentralDirectoryData(final byte[] buffer, final int offset,
113                                              final int length) {
114        centralDirectoryData = Arrays.copyOfRange(buffer, offset, offset + length);
115        if (localFileData == null) {
116            parseFromLocalFileData(buffer, offset, length);
117        }
118    }
119
120}