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}