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