    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.zip.ZipException;
    022
    023/**
    024 * X.509 Certificate ID and Signature for central directory (0x0016).
    025 *
    026 * <p>This field contains the information about which certificate in the PKCS#7
    027 * store was used to sign the central directory structure. When the Central
    028 * Directory Encryption feature is enabled for a ZIP file, this record will
    029 * appear in the Archive Extra Data Record, otherwise it will appear in the
    030 * first central directory record.</p>
    031 *
    032 * <p>Note: all fields stored in Intel low-byte/high-byte order.</p>
    033 *
    034 * <pre>
    035 *         Value     Size     Description
    036 *         -----     ----     -----------
    037 * (CDID)  0x0016    2 bytes  Tag for this "extra" block type
    038 *         TSize     2 bytes  Size of data that follows
    039 *         RCount    4 bytes  Number of recipients. (inferred)
    040 *         HashAlg   2 bytes  Hash algorithm identifier. (inferred)
    041 *         TData     TSize    Data
    042 * </pre>
    043 *
    044 * @NotThreadSafe
    045 * @since 1.11
    046 */
    047public class X0016_CertificateIdForCentralDirectory extends PKWareExtraHeader {
    048
    049    private int rcount;
    050
    051    private HashAlgorithm hashAlg;
    052    public X0016_CertificateIdForCentralDirectory() {
    053        super(new ZipShort(0x0016));
    054    }
    055
    056    /**
    057     * Get hash algorithm.
    058     * @return the hash algorithm
    059     */
    060    public HashAlgorithm getHashAlgorithm() {
    061        return hashAlg;
    062    }
    063
    064    /**
    065     * Get record count.
    066     * @return the record count
    067     */
    068    public int getRecordCount() {
    069        return rcount;
    070    }
    071
    072    @Override
    073    public void parseFromCentralDirectoryData(final byte[] data, final int offset, final int length)
    074        throws ZipException {
    075        assertMinimalLength(4, length);
    076        // TODO: double check we really do not want to call super here
    077        this.rcount = ZipShort.getValue(data, offset);
    078        this.hashAlg = HashAlgorithm.getAlgorithmByCode(ZipShort.getValue(data, offset + 2));
    079    }
    080}