    001/*
    002 *  Licensed to the Apache Software Foundation (ASF) under one or more
    003 *  contributor license agreements.  See the NOTICE file distributed with
    004 *  this work for additional information regarding copyright ownership.
    005 *  The ASF licenses this file to You under the Apache License, Version 2.0
    006 *  (the "License"); you may not use this file except in compliance with
    007 *  the License.  You may obtain a copy of the License at
    008 *
    009 *      http://www.apache.org/licenses/LICENSE-2.0
    010 *
    011 *  Unless required by applicable law or agreed to in writing, software
    012 *  distributed under the License is distributed on an "AS IS" BASIS,
    013 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014 *  See the License for the specific language governing permissions and
    015 *  limitations under the License.
    016 */
    017
    018package org.apache.commons.compress.archivers.zip;
    019
    020import static java.nio.charset.StandardCharsets.UTF_8;
    021
    022import java.util.Arrays;
    023import java.util.zip.CRC32;
    024import java.util.zip.ZipException;
    025
    026/**
    027 * A common base class for Unicode extra information extra fields.
    028 * @NotThreadSafe
    029 */
    030public abstract class AbstractUnicodeExtraField implements ZipExtraField {
    031    private long nameCRC32;
    032    private byte[] unicodeName;
    033    private byte[] data;
    034
    035    protected AbstractUnicodeExtraField() {
    036    }
    037
    038    /**
    039     * Assemble as unicode extension from the name/comment and
    040     * encoding of the original ZIP entry.
    041     *
    042     * @param text The file name or comment.
    043     * @param bytes The encoded of the file name or comment in the ZIP
    044     * file.
    045     */
    046    protected AbstractUnicodeExtraField(final String text, final byte[] bytes) {
    047        this(text, bytes, 0, bytes.length);
    048    }
    049
    050    /**
    051     * Assemble as unicode extension from the name/comment and
    052     * encoding of the original ZIP entry.
    053     *
    054     * @param text The file name or comment.
    055     * @param bytes The encoded of the file name or comment in the ZIP
    056     * file.
    057     * @param off The offset of the encoded file name or comment in
    058     * {@code bytes}.
    059     * @param len The length of the encoded file name or comment in
    060     * {@code bytes}.
    061     */
    062    protected AbstractUnicodeExtraField(final String text, final byte[] bytes, final int off, final int len) {
    063        final CRC32 crc32 = new CRC32();
    064        crc32.update(bytes, off, len);
    065        nameCRC32 = crc32.getValue();
    066
    067        unicodeName = text.getBytes(UTF_8);
    068    }
    069
    070    private void assembleData() {
    071        if (unicodeName == null) {
    072            return;
    073        }
    074
    075        data = new byte[5 + unicodeName.length];
    076        // version 1
    077        data[0] = 0x01;
    078        System.arraycopy(ZipLong.getBytes(nameCRC32), 0, data, 1, 4);
    079        System.arraycopy(unicodeName, 0, data, 5, unicodeName.length);
    080    }
    081
    082    @Override
    083    public byte[] getCentralDirectoryData() {
    084        if (data == null) {
    085            this.assembleData();
    086        }
    087        byte[] b = null;
    088        if (data != null) {
    089            b = Arrays.copyOf(data, data.length);
    090        }
    091        return b;
    092    }
    093
    094    @Override
    095    public ZipShort getCentralDirectoryLength() {
    096        if (data == null) {
    097            assembleData();
    098        }
    099        return new ZipShort(data != null ? data.length : 0);
    100    }
    101
    102    @Override
    103    public byte[] getLocalFileDataData() {
    104        return getCentralDirectoryData();
    105    }
    106
    107    @Override
    108    public ZipShort getLocalFileDataLength() {
    109        return getCentralDirectoryLength();
    110    }
    111
    112    /**
    113     * @return The CRC32 checksum of the file name or comment as
    114     *         encoded in the central directory of the ZIP file.
    115     */
    116    public long getNameCRC32() {
    117        return nameCRC32;
    118    }
    119
    120    /**
    121     * @return The UTF-8 encoded name.
    122     */
    123    public byte[] getUnicodeName() {
    124        return unicodeName != null ? Arrays.copyOf(unicodeName, unicodeName.length) : null;
    125    }
    126
    127    /**
    128     * Doesn't do anything special since this class always uses the
    129     * same data in central directory and local file data.
    130     */
    131    @Override
    132    public void parseFromCentralDirectoryData(final byte[] buffer, final int offset,
    133                                              final int length)
    134        throws ZipException {
    135        parseFromLocalFileData(buffer, offset, length);
    136    }
    137
    138    @Override
    139    public void parseFromLocalFileData(final byte[] buffer, final int offset, final int length)
    140        throws ZipException {
    141
    142        if (length < 5) {
    143            throw new ZipException("UniCode path extra data must have at least 5 bytes.");
    144        }
    145
    146        final int version = buffer[offset];
    147
    148        if (version != 0x01) {
    149            throw new ZipException("Unsupported version [" + version
    150                                   + "] for UniCode path extra data.");
    151        }
    152
    153        nameCRC32 = ZipLong.getValue(buffer, offset + 1);
    154        unicodeName = new byte[length - 5];
    155        System.arraycopy(buffer, offset + 5, unicodeName, 0, length - 5);
    156        data = null;
    157    }
    158
    159    /**
    160     * @param nameCRC32 The CRC32 checksum of the file name as encoded
    161     *         in the central directory of the ZIP file to set.
    162     */
    163    public void setNameCRC32(final long nameCRC32) {
    164        this.nameCRC32 = nameCRC32;
    165        data = null;
    166    }
    167
    168    /**
    169     * @param unicodeName The UTF-8 encoded name to set.
    170     */
    171    public void setUnicodeName(final byte[] unicodeName) {
    172        if (unicodeName != null) {
    173            this.unicodeName = Arrays.copyOf(unicodeName, unicodeName.length);
    174        } else {
    175            this.unicodeName = null;
    176        }
    177        data = null;
    178    }
    179}