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 */
017package org.apache.commons.compress.archivers.sevenz;
018
019import static java.nio.charset.StandardCharsets.UTF_16LE;
020
021import java.io.BufferedInputStream;
022import java.io.ByteArrayInputStream;
023import java.io.Closeable;
024import java.io.DataInputStream;
025import java.io.EOFException;
026import java.io.File;
027import java.io.FilterInputStream;
028import java.io.IOException;
029import java.io.InputStream;
030import java.nio.ByteBuffer;
031import java.nio.ByteOrder;
032import java.nio.channels.Channels;
033import java.nio.channels.SeekableByteChannel;
034import java.nio.file.Files;
035import java.nio.file.OpenOption;
036import java.nio.file.Path;
037import java.nio.file.StandardOpenOption;
038import java.util.ArrayList;
039import java.util.Arrays;
040import java.util.BitSet;
041import java.util.EnumSet;
042import java.util.LinkedHashMap;
043import java.util.LinkedList;
044import java.util.List;
045import java.util.Map;
046import java.util.Objects;
047import java.util.zip.CRC32;
048import java.util.zip.CheckedInputStream;
049
050import org.apache.commons.compress.MemoryLimitException;
051import org.apache.commons.compress.utils.BoundedInputStream;
052import org.apache.commons.compress.utils.ByteUtils;
053import org.apache.commons.compress.utils.CRC32VerifyingInputStream;
054import org.apache.commons.compress.utils.IOUtils;
055import org.apache.commons.compress.utils.InputStreamStatistics;
056import org.apache.commons.compress.utils.SeekableInMemoryByteChannel;
057import org.apache.commons.io.build.AbstractOrigin.ByteArrayOrigin;
058import org.apache.commons.io.build.AbstractStreamBuilder;
059
060/**
061 * Reads a 7z file, using SeekableByteChannel under the covers.
062 * <p>
063 * The 7z file format is a flexible container that can contain many compression and encryption types, but at the moment only only Copy, LZMA, LZMA2, BZIP2,
064 * Deflate and AES-256 + SHA-256 are supported.
065 * </p>
066 * <p>
067 * The format is very Windows/Intel specific, so it uses little-endian byte order, doesn't store user/group or permission bits, and represents times using NTFS
068 * timestamps (100 nanosecond units since 1 January 1601). Hence the official tools recommend against using it for backup purposes on *nix, and recommend
069 * .tar.7z or .tar.lzma or .tar.xz instead.
070 * </p>
071 * <p>
072 * Both the header and file contents may be compressed and/or encrypted. With both encrypted, neither file names nor file contents can be read, but the use of
073 * encryption isn't plausibly deniable.
074 * </p>
075 * <p>
076 * Multi volume archives can be read by concatenating the parts in correct order - either manually or by using {link
077 * org.apache.commons.compress.utils.MultiReadOnlySeekableByteChannel} for example.
078 * </p>
079 *
080 * @NotThreadSafe
081 * @since 1.6
082 */
083public class SevenZFile implements Closeable {
084
085    private static final class ArchiveStatistics {
086        private int numberOfPackedStreams;
087        private long numberOfCoders;
088        private long numberOfOutStreams;
089        private long numberOfInStreams;
090        private long numberOfUnpackSubStreams;
091        private int numberOfFolders;
092        private BitSet folderHasCrc;
093        private int numberOfEntries;
094        private int numberOfEntriesWithStream;
095
096        void assertValidity(final int maxMemoryLimitInKb) throws IOException {
097            if (numberOfEntriesWithStream > 0 && numberOfFolders == 0) {
098                throw new IOException("archive with entries but no folders");
099            }
100            if (numberOfEntriesWithStream > numberOfUnpackSubStreams) {
101                throw new IOException("archive doesn't contain enough substreams for entries");
102            }
103
104            final long memoryNeededInKb = estimateSize() / 1024;
105            if (maxMemoryLimitInKb < memoryNeededInKb) {
106                throw new MemoryLimitException(memoryNeededInKb, maxMemoryLimitInKb);
107            }
108        }
109
110        private long bindPairSize() {
111            return 16;
112        }
113
114        private long coderSize() {
115            return 2 /* methodId is between 1 and four bytes currently, COPY and LZMA2 are the most common with 1 */
116                    + 16 + 4 /* properties, guess */
117            ;
118        }
119
120        private long entrySize() {
121            return 100; /* real size depends on name length, everything without name is about 70 bytes */
122        }
123
124        long estimateSize() {
125            final long lowerBound = 16L * numberOfPackedStreams /* packSizes, packCrcs in Archive */
126                    + numberOfPackedStreams / 8 /* packCrcsDefined in Archive */
127                    + numberOfFolders * folderSize() /* folders in Archive */
128                    + numberOfCoders * coderSize() /* coders in Folder */
129                    + (numberOfOutStreams - numberOfFolders) * bindPairSize() /* bindPairs in Folder */
130                    + 8L * (numberOfInStreams - numberOfOutStreams + numberOfFolders) /* packedStreams in Folder */
131                    + 8L * numberOfOutStreams /* unpackSizes in Folder */
132                    + numberOfEntries * entrySize() /* files in Archive */
133                    + streamMapSize();
134            return 2 * lowerBound /* conservative guess */;
135        }
136
137        private long folderSize() {
138            return 30; /* nested arrays are accounted for separately */
139        }
140
141        private long streamMapSize() {
142            return 8 * numberOfFolders /* folderFirstPackStreamIndex, folderFirstFileIndex */
143                    + 8 * numberOfPackedStreams /* packStreamOffsets */
144                    + 4 * numberOfEntries /* fileFolderIndex */
145            ;
146        }
147
148        @Override
149        public String toString() {
150            return "Archive with " + numberOfEntries + " entries in " + numberOfFolders + " folders. Estimated size " + estimateSize() / 1024L + " kB.";
151        }
152    }
153
154    /**
155     * Builds new instances of {@link SevenZFile}.
156     *
157     * @since 1.26.0
158     */
159    public static class Builder extends AbstractStreamBuilder<SevenZFile, Builder> {
160
161        static final int MEMORY_LIMIT_IN_KB = Integer.MAX_VALUE;
162        static final boolean USE_DEFAULTNAME_FOR_UNNAMED_ENTRIES = false;
163        static final boolean TRY_TO_RECOVER_BROKEN_ARCHIVES = false;
164
165        private SeekableByteChannel seekableByteChannel;
166        private String defaultName = DEFAULT_FILE_NAME;
167        private byte[] password;
168        private int maxMemoryLimitKb = MEMORY_LIMIT_IN_KB;
169        private boolean useDefaultNameForUnnamedEntries = USE_DEFAULTNAME_FOR_UNNAMED_ENTRIES;
170        private boolean tryToRecoverBrokenArchives = TRY_TO_RECOVER_BROKEN_ARCHIVES;
171
172        @SuppressWarnings("resource") // Caller closes
173        @Override
174        public SevenZFile get() throws IOException {
175            final SeekableByteChannel actualChannel;
176            final String actualDescription;
177            if (seekableByteChannel != null) {
178                actualChannel = seekableByteChannel;
179                actualDescription = defaultName;
180            } else if (checkOrigin() instanceof ByteArrayOrigin) {
181                actualChannel = new SeekableInMemoryByteChannel(checkOrigin().getByteArray());
182                actualDescription = defaultName;
183            } else {
184                OpenOption[] openOptions = getOpenOptions();
185                if (openOptions.length == 0) {
186                    openOptions = new OpenOption[] { StandardOpenOption.READ };
187                }
188                final Path path = getPath();
189                actualChannel = Files.newByteChannel(path, openOptions);
190                actualDescription = path.toAbsolutePath().toString();
191            }
192            final boolean closeOnError = seekableByteChannel != null;
193            return new SevenZFile(actualChannel, actualDescription, password, closeOnError, maxMemoryLimitKb, useDefaultNameForUnnamedEntries,
194                    tryToRecoverBrokenArchives);
195        }
196
197        /**
198         * Sets the default name.
199         *
200         * @param defaultName the default name.
201         * @return this.
202         */
203        public Builder setDefaultName(final String defaultName) {
204            this.defaultName = defaultName;
205            return this;
206        }
207
208        /**
209         * Sets the maximum amount of memory in kilobytes to use for parsing the archive and during extraction.
210         * <p>
211         * Not all codecs honor this setting. Currently only LZMA and LZMA2 are supported.
212         * </p>
213         *
214         * @param maxMemoryLimitKb the max memory limit in kilobytes.
215         * @return this.
216         */
217        public Builder setMaxMemoryLimitKb(final int maxMemoryLimitKb) {
218            this.maxMemoryLimitKb = maxMemoryLimitKb;
219            return this;
220        }
221
222        /**
223         * Sets the password.
224         *
225         * @param password the password.
226         * @return this.
227         */
228        public Builder setPassword(final byte[] password) {
229            this.password = password != null ? password.clone() : null;
230            return this;
231        }
232
233        /**
234         * Sets the password.
235         *
236         * @param password the password.
237         * @return this.
238         */
239        public Builder setPassword(final char[] password) {
240            this.password = password != null ? AES256SHA256Decoder.utf16Decode(password.clone()) : null;
241            return this;
242        }
243
244        /**
245         * Sets the password.
246         *
247         * @param password the password.
248         * @return this.
249         */
250        public Builder setPassword(final String password) {
251            this.password = password != null ? AES256SHA256Decoder.utf16Decode(password.toCharArray()) : null;
252            return this;
253        }
254
255        /**
256         * Sets the input channel.
257         *
258         * @param seekableByteChannel the input channel.
259         * @return this.
260         */
261        public Builder setSeekableByteChannel(final SeekableByteChannel seekableByteChannel) {
262            this.seekableByteChannel = seekableByteChannel;
263            return this;
264        }
265
266        /**
267         * Sets whether {@link SevenZFile} will try to recover broken archives where the CRC of the file's metadata is 0.
268         * <p>
269         * This special kind of broken archive is encountered when mutli volume archives are closed prematurely. If you enable this option SevenZFile will trust
270         * data that looks as if it could contain metadata of an archive and allocate big amounts of memory. It is strongly recommended to not enable this
271         * option without setting {@link #setMaxMemoryLimitKb(int)} at the same time.
272         * </p>
273         *
274         * @param tryToRecoverBrokenArchives whether {@link SevenZFile} will try to recover broken archives where the CRC of the file's metadata is 0.
275         * @return this.
276         */
277        public Builder setTryToRecoverBrokenArchives(final boolean tryToRecoverBrokenArchives) {
278            this.tryToRecoverBrokenArchives = tryToRecoverBrokenArchives;
279            return this;
280        }
281
282        /**
283         * Sets whether entries without a name should get their names set to the archive's default file name.
284         *
285         * @param useDefaultNameForUnnamedEntries whether entries without a name should get their names set to the archive's default file name.
286         * @return this.
287         */
288        public Builder setUseDefaultNameForUnnamedEntries(final boolean useDefaultNameForUnnamedEntries) {
289            this.useDefaultNameForUnnamedEntries = useDefaultNameForUnnamedEntries;
290            return this;
291        }
292
293    }
294
295    static final int SIGNATURE_HEADER_SIZE = 32;
296
297    private static final String DEFAULT_FILE_NAME = "unknown archive";
298
299    /** Shared with SevenZOutputFile and tests, neither mutates it. */
300    static final byte[] sevenZSignature = { // NOSONAR
301            (byte) '7', (byte) 'z', (byte) 0xBC, (byte) 0xAF, (byte) 0x27, (byte) 0x1C };
302
303    private static int assertFitsIntoNonNegativeInt(final String what, final long value) throws IOException {
304        if (value > Integer.MAX_VALUE || value < 0) {
305            throw new IOException(String.format("Cannot handle % %,d", what, value));
306        }
307        return (int) value;
308    }
309
310    /**
311     * Creates a new Builder.
312     *
313     * @return a new Builder.
314     * @since 1.26.0
315     */
316    public static Builder builder() {
317        return new Builder();
318    }
319
320    private static ByteBuffer checkEndOfFile(final ByteBuffer buf, final int expectRemaining) throws EOFException {
321        final int remaining = buf.remaining();
322        if (remaining < expectRemaining) {
323            throw new EOFException(String.format("remaining %,d < expectRemaining %,d", remaining, expectRemaining));
324        }
325        return buf;
326    }
327
328    private static void get(final ByteBuffer buf, final byte[] to) throws EOFException {
329        checkEndOfFile(buf, to.length).get(to);
330    }
331
332    private static char getChar(final ByteBuffer buf) throws EOFException {
333        return checkEndOfFile(buf, Character.BYTES).getChar();
334    }
335
336    private static int getInt(final ByteBuffer buf) throws EOFException {
337        return checkEndOfFile(buf, Integer.BYTES).getInt();
338    }
339
340    private static long getLong(final ByteBuffer buf) throws EOFException {
341        return checkEndOfFile(buf, Long.BYTES).getLong();
342    }
343
344    private static int getUnsignedByte(final ByteBuffer buf) throws EOFException {
345        if (!buf.hasRemaining()) {
346            throw new EOFException();
347        }
348        return buf.get() & 0xff;
349    }
350
351    /**
352     * Checks if the signature matches what is expected for a 7z file.
353     *
354     * @param signature the bytes to check
355     * @param length    the number of bytes to check
356     * @return true, if this is the signature of a 7z archive.
357     * @since 1.8
358     */
359    public static boolean matches(final byte[] signature, final int length) {
360        if (length < sevenZSignature.length) {
361            return false;
362        }
363        for (int i = 0; i < sevenZSignature.length; i++) {
364            if (signature[i] != sevenZSignature[i]) {
365                return false;
366            }
367        }
368        return true;
369    }
370
371    private static SeekableByteChannel newByteChannel(final File file) throws IOException {
372        return Files.newByteChannel(file.toPath(), EnumSet.of(StandardOpenOption.READ));
373    }
374
375    private static long readUint64(final ByteBuffer in) throws IOException {
376        // long rather than int as it might get shifted beyond the range of an int
377        final long firstByte = getUnsignedByte(in);
378        int mask = 0x80;
379        long value = 0;
380        for (int i = 0; i < 8; i++) {
381            if ((firstByte & mask) == 0) {
382                return value | (firstByte & mask - 1) << 8 * i;
383            }
384            final long nextByte = getUnsignedByte(in);
385            value |= nextByte << 8 * i;
386            mask >>>= 1;
387        }
388        return value;
389    }
390
391    private static long skipBytesFully(final ByteBuffer input, long bytesToSkip) {
392        if (bytesToSkip < 1) {
393            return 0;
394        }
395        final int current = input.position();
396        final int maxSkip = input.remaining();
397        if (maxSkip < bytesToSkip) {
398            bytesToSkip = maxSkip;
399        }
400        input.position(current + (int) bytesToSkip);
401        return bytesToSkip;
402    }
403
404    private final String fileName;
405    private SeekableByteChannel channel;
406    private final Archive archive;
407    private int currentEntryIndex = -1;
408    private int currentFolderIndex = -1;
409    private InputStream currentFolderInputStream;
410    private byte[] password;
411    private long compressedBytesReadFromCurrentEntry;
412    private long uncompressedBytesReadFromCurrentEntry;
413    private final ArrayList<InputStream> deferredBlockStreams = new ArrayList<>();
414    private final int maxMemoryLimitKb;
415    private final boolean useDefaultNameForUnnamedEntries;
416
417    private final boolean tryToRecoverBrokenArchives;
418
419    /**
420     * Reads a file as unencrypted 7z archive.
421     *
422     * @param fileName the file to read.
423     * @throws IOException if reading the archive fails.
424     * @deprecated Use {@link Builder#get()}.
425     */
426    @Deprecated
427    public SevenZFile(final File fileName) throws IOException {
428        this(fileName, SevenZFileOptions.DEFAULT);
429    }
430
431    /**
432     * Reads a file as 7z archive
433     *
434     * @param file     the file to read
435     * @param password optional password if the archive is encrypted - the byte array is supposed to be the UTF16-LE encoded representation of the password.
436     * @throws IOException if reading the archive fails
437     * @deprecated Use {@link Builder#get()}.
438     */
439    @SuppressWarnings("resource") // caller closes
440    @Deprecated
441    public SevenZFile(final File file, final byte[] password) throws IOException {
442        this(newByteChannel(file), file.getAbsolutePath(), password, true, SevenZFileOptions.DEFAULT);
443    }
444
445    /**
446     * Reads a file as 7z archive
447     *
448     * @param file     the file to read
449     * @param password optional password if the archive is encrypted
450     * @throws IOException if reading the archive fails
451     * @since 1.17
452     * @deprecated Use {@link Builder#get()}.
453     */
454    @Deprecated
455    public SevenZFile(final File file, final char[] password) throws IOException {
456        this(file, password, SevenZFileOptions.DEFAULT);
457    }
458
459    /**
460     * Reads a file as 7z archive with additional options.
461     *
462     * @param file     the file to read
463     * @param password optional password if the archive is encrypted
464     * @param options  the options to apply
465     * @throws IOException if reading the archive fails or the memory limit (if set) is too small
466     * @since 1.19
467     * @deprecated Use {@link Builder#get()}.
468     */
469    @SuppressWarnings("resource") // caller closes
470    @Deprecated
471    public SevenZFile(final File file, final char[] password, final SevenZFileOptions options) throws IOException {
472        this(newByteChannel(file), // NOSONAR
473                file.getAbsolutePath(), AES256SHA256Decoder.utf16Decode(password), true, options);
474    }
475
476    /**
477     * Reads a file as unencrypted 7z archive
478     *
479     * @param file    the file to read
480     * @param options the options to apply
481     * @throws IOException if reading the archive fails or the memory limit (if set) is too small
482     * @since 1.19
483     * @deprecated Use {@link Builder#get()}.
484     */
485    @Deprecated
486    public SevenZFile(final File file, final SevenZFileOptions options) throws IOException {
487        this(file, null, options);
488    }
489
490    /**
491     * Reads a SeekableByteChannel as 7z archive
492     * <p>
493     * {@link org.apache.commons.compress.utils.SeekableInMemoryByteChannel} allows you to read from an in-memory archive.
494     * </p>
495     *
496     * @param channel the channel to read
497     * @throws IOException if reading the archive fails
498     * @since 1.13
499     * @deprecated Use {@link Builder#get()}.
500     */
501    @Deprecated
502    public SevenZFile(final SeekableByteChannel channel) throws IOException {
503        this(channel, SevenZFileOptions.DEFAULT);
504    }
505
506    /**
507     * Reads a SeekableByteChannel as 7z archive
508     * <p>
509     * {@link org.apache.commons.compress.utils.SeekableInMemoryByteChannel} allows you to read from an in-memory archive.
510     * </p>
511     *
512     * @param channel  the channel to read
513     * @param password optional password if the archive is encrypted - the byte array is supposed to be the UTF16-LE encoded representation of the password.
514     * @throws IOException if reading the archive fails
515     * @since 1.13
516     * @deprecated Use {@link Builder#get()}.
517     */
518    @Deprecated
519    public SevenZFile(final SeekableByteChannel channel, final byte[] password) throws IOException {
520        this(channel, DEFAULT_FILE_NAME, password);
521    }
522
523    /**
524     * Reads a SeekableByteChannel as 7z archive
525     * <p>
526     * {@link org.apache.commons.compress.utils.SeekableInMemoryByteChannel} allows you to read from an in-memory archive.
527     * </p>
528     *
529     * @param channel  the channel to read
530     * @param password optional password if the archive is encrypted
531     * @throws IOException if reading the archive fails
532     * @since 1.17
533     * @deprecated Use {@link Builder#get()}.
534     */
535    @Deprecated
536    public SevenZFile(final SeekableByteChannel channel, final char[] password) throws IOException {
537        this(channel, password, SevenZFileOptions.DEFAULT);
538    }
539
540    /**
541     * Reads a SeekableByteChannel as 7z archive with additional options.
542     * <p>
543     * {@link org.apache.commons.compress.utils.SeekableInMemoryByteChannel} allows you to read from an in-memory archive.
544     * </p>
545     *
546     * @param channel  the channel to read
547     * @param password optional password if the archive is encrypted
548     * @param options  the options to apply
549     * @throws IOException if reading the archive fails or the memory limit (if set) is too small
550     * @since 1.19
551     * @deprecated Use {@link Builder#get()}.
552     */
553    @Deprecated
554    public SevenZFile(final SeekableByteChannel channel, final char[] password, final SevenZFileOptions options) throws IOException {
555        this(channel, DEFAULT_FILE_NAME, password, options);
556    }
557
558    /**
559     * Reads a SeekableByteChannel as 7z archive with additional options.
560     * <p>
561     * {@link org.apache.commons.compress.utils.SeekableInMemoryByteChannel} allows you to read from an in-memory archive.
562     * </p>
563     *
564     * @param channel the channel to read
565     * @param options the options to apply
566     * @throws IOException if reading the archive fails or the memory limit (if set) is too small
567     * @since 1.19
568     * @deprecated Use {@link Builder#get()}.
569     */
570    @Deprecated
571    public SevenZFile(final SeekableByteChannel channel, final SevenZFileOptions options) throws IOException {
572        this(channel, DEFAULT_FILE_NAME, null, options);
573    }
574
575    /**
576     * Reads a SeekableByteChannel as 7z archive
577     * <p>
578     * {@link org.apache.commons.compress.utils.SeekableInMemoryByteChannel} allows you to read from an in-memory archive.
579     * </p>
580     *
581     * @param channel  the channel to read
582     * @param fileName name of the archive - only used for error reporting
583     * @throws IOException if reading the archive fails
584     * @since 1.17
585     * @deprecated Use {@link Builder#get()}.
586     */
587    @Deprecated
588    public SevenZFile(final SeekableByteChannel channel, final String fileName) throws IOException {
589        this(channel, fileName, SevenZFileOptions.DEFAULT);
590    }
591
592    /**
593     * Reads a SeekableByteChannel as 7z archive
594     * <p>
595     * {@link org.apache.commons.compress.utils.SeekableInMemoryByteChannel} allows you to read from an in-memory archive.
596     * </p>
597     *
598     * @param channel  the channel to read
599     * @param fileName name of the archive - only used for error reporting
600     * @param password optional password if the archive is encrypted - the byte array is supposed to be the UTF16-LE encoded representation of the password.
601     * @throws IOException if reading the archive fails
602     * @since 1.13
603     * @deprecated Use {@link Builder#get()}.
604     */
605    @Deprecated
606    public SevenZFile(final SeekableByteChannel channel, final String fileName, final byte[] password) throws IOException {
607        this(channel, fileName, password, false, SevenZFileOptions.DEFAULT);
608    }
609
610    private SevenZFile(final SeekableByteChannel channel, final String fileName, final byte[] password, final boolean closeOnError, final int maxMemoryLimitKb,
611            final boolean useDefaultNameForUnnamedEntries, final boolean tryToRecoverBrokenArchives) throws IOException {
612        boolean succeeded = false;
613        this.channel = channel;
614        this.fileName = fileName;
615        this.maxMemoryLimitKb = maxMemoryLimitKb;
616        this.useDefaultNameForUnnamedEntries = useDefaultNameForUnnamedEntries;
617        this.tryToRecoverBrokenArchives = tryToRecoverBrokenArchives;
618        try {
619            archive = readHeaders(password);
620            if (password != null) {
621                this.password = Arrays.copyOf(password, password.length);
622            } else {
623                this.password = null;
624            }
625            succeeded = true;
626        } finally {
627            if (!succeeded && closeOnError) {
628                this.channel.close();
629            }
630        }
631    }
632
633    /**
634     * Constructs a new instance.
635     *
636     * @param channel      the channel to read.
637     * @param fileName     name of the archive - only used for error reporting.
638     * @param password     optional password if the archive is encrypted.
639     * @param closeOnError closes the channel on error.
640     * @param options      options.
641     * @throws IOException if reading the archive fails
642     * @deprecated Use {@link Builder#get()}.
643     */
644    @Deprecated
645    private SevenZFile(final SeekableByteChannel channel, final String fileName, final byte[] password, final boolean closeOnError,
646            final SevenZFileOptions options) throws IOException {
647        this(channel, fileName, password, closeOnError, options.getMaxMemoryLimitInKb(), options.getUseDefaultNameForUnnamedEntries(),
648                options.getTryToRecoverBrokenArchives());
649    }
650
651    /**
652     * Reads a SeekableByteChannel as 7z archive
653     * <p>
654     * {@link org.apache.commons.compress.utils.SeekableInMemoryByteChannel} allows you to read from an in-memory archive.
655     * </p>
656     *
657     * @param channel  the channel to read
658     * @param fileName name of the archive - only used for error reporting
659     * @param password optional password if the archive is encrypted
660     * @throws IOException if reading the archive fails
661     * @since 1.17
662     * @deprecated Use {@link Builder#get()}.
663     */
664    @Deprecated
665    public SevenZFile(final SeekableByteChannel channel, final String fileName, final char[] password) throws IOException {
666        this(channel, fileName, password, SevenZFileOptions.DEFAULT);
667    }
668
669    /**
670     * Reads a SeekableByteChannel as 7z archive with additional options.
671     * <p>
672     * {@link org.apache.commons.compress.utils.SeekableInMemoryByteChannel} allows you to read from an in-memory archive.
673     * </p>
674     *
675     * @param channel  the channel to read
676     * @param fileName name of the archive - only used for error reporting
677     * @param password optional password if the archive is encrypted
678     * @param options  the options to apply
679     * @throws IOException if reading the archive fails or the memory limit (if set) is too small
680     * @since 1.19
681     * @deprecated Use {@link Builder#get()}.
682     */
683    @Deprecated
684    public SevenZFile(final SeekableByteChannel channel, final String fileName, final char[] password, final SevenZFileOptions options) throws IOException {
685        this(channel, fileName, AES256SHA256Decoder.utf16Decode(password), false, options);
686    }
687
688    /**
689     * Reads a SeekableByteChannel as 7z archive with additional options.
690     * <p>
691     * {@link org.apache.commons.compress.utils.SeekableInMemoryByteChannel} allows you to read from an in-memory archive.
692     * </p>
693     *
694     * @param channel  the channel to read
695     * @param fileName name of the archive - only used for error reporting
696     * @param options  the options to apply
697     * @throws IOException if reading the archive fails or the memory limit (if set) is too small
698     * @since 1.19
699     * @deprecated Use {@link Builder#get()}.
700     */
701    @Deprecated
702    public SevenZFile(final SeekableByteChannel channel, final String fileName, final SevenZFileOptions options) throws IOException {
703        this(channel, fileName, null, false, options);
704    }
705
706    private InputStream buildDecoderStack(final Folder folder, final long folderOffset, final int firstPackStreamIndex, final SevenZArchiveEntry entry)
707            throws IOException {
708        channel.position(folderOffset);
709        InputStream inputStreamStack = new FilterInputStream(
710                new BufferedInputStream(new BoundedSeekableByteChannelInputStream(channel, archive.packSizes[firstPackStreamIndex]))) {
711            private void count(final int c) {
712                compressedBytesReadFromCurrentEntry += c;
713            }
714
715            @Override
716            public int read() throws IOException {
717                final int r = in.read();
718                if (r >= 0) {
719                    count(1);
720                }
721                return r;
722            }
723
724            @Override
725            public int read(final byte[] b) throws IOException {
726                return read(b, 0, b.length);
727            }
728
729            @Override
730            public int read(final byte[] b, final int off, final int len) throws IOException {
731                if (len == 0) {
732                    return 0;
733                }
734                final int r = in.read(b, off, len);
735                if (r >= 0) {
736                    count(r);
737                }
738                return r;
739            }
740        };
741        final LinkedList<SevenZMethodConfiguration> methods = new LinkedList<>();
742        for (final Coder coder : folder.getOrderedCoders()) {
743            if (coder.numInStreams != 1 || coder.numOutStreams != 1) {
744                throw new IOException("Multi input/output stream coders are not yet supported");
745            }
746            final SevenZMethod method = SevenZMethod.byId(coder.decompressionMethodId);
747            inputStreamStack = Coders.addDecoder(fileName, inputStreamStack, folder.getUnpackSizeForCoder(coder), coder, password, maxMemoryLimitKb);
748            methods.addFirst(new SevenZMethodConfiguration(method, Coders.findByMethod(method).getOptionsFromCoder(coder, inputStreamStack)));
749        }
750        entry.setContentMethods(methods);
751        if (folder.hasCrc) {
752            return new CRC32VerifyingInputStream(inputStreamStack, folder.getUnpackSize(), folder.crc);
753        }
754        return inputStreamStack;
755    }
756
757    /**
758     * Builds the decoding stream for the entry to be read. This method may be called from a random access(getInputStream) or sequential access(getNextEntry).
759     * If this method is called from a random access, some entries may need to be skipped(we put them to the deferredBlockStreams and skip them when actually
760     * needed to improve the performance)
761     *
762     * @param entryIndex     the index of the entry to be read
763     * @param isRandomAccess is this called in a random access
764     * @throws IOException if there are exceptions when reading the file
765     */
766    private void buildDecodingStream(final int entryIndex, final boolean isRandomAccess) throws IOException {
767        if (archive.streamMap == null) {
768            throw new IOException("Archive doesn't contain stream information to read entries");
769        }
770        final int folderIndex = archive.streamMap.fileFolderIndex[entryIndex];
771        if (folderIndex < 0) {
772            deferredBlockStreams.clear();
773            // TODO: previously it'd return an empty stream?
774            // new BoundedInputStream(new ByteArrayInputStream(ByteUtils.EMPTY_BYTE_ARRAY), 0);
775            return;
776        }
777        final SevenZArchiveEntry file = archive.files[entryIndex];
778        boolean isInSameFolder = false;
779        if (currentFolderIndex == folderIndex) {
780            // (COMPRESS-320).
781            // The current entry is within the same (potentially opened) folder. The
782            // previous stream has to be fully decoded before we can start reading
783            // but don't do it eagerly -- if the user skips over the entire folder nothing
784            // is effectively decompressed.
785            if (entryIndex > 0) {
786                file.setContentMethods(archive.files[entryIndex - 1].getContentMethods());
787            }
788
789            // if this is called in a random access, then the content methods of previous entry may be null
790            // the content methods should be set to methods of the first entry as it must not be null,
791            // and the content methods would only be set if the content methods was not set
792            if (isRandomAccess && file.getContentMethods() == null) {
793                final int folderFirstFileIndex = archive.streamMap.folderFirstFileIndex[folderIndex];
794                final SevenZArchiveEntry folderFirstFile = archive.files[folderFirstFileIndex];
795                file.setContentMethods(folderFirstFile.getContentMethods());
796            }
797            isInSameFolder = true;
798        } else {
799            currentFolderIndex = folderIndex;
800            // We're opening a new folder. Discard any queued streams/ folder stream.
801            reopenFolderInputStream(folderIndex, file);
802        }
803
804        boolean haveSkippedEntries = false;
805        if (isRandomAccess) {
806            // entries will only need to be skipped if it's a random access
807            haveSkippedEntries = skipEntriesWhenNeeded(entryIndex, isInSameFolder, folderIndex);
808        }
809
810        if (isRandomAccess && currentEntryIndex == entryIndex && !haveSkippedEntries) {
811            // we don't need to add another entry to the deferredBlockStreams when :
812            // 1. If this method is called in a random access and the entry index
813            // to be read equals to the current entry index, the input stream
814            // has already been put in the deferredBlockStreams
815            // 2. If this entry has not been read(which means no entries are skipped)
816            return;
817        }
818
819        InputStream fileStream = new BoundedInputStream(currentFolderInputStream, file.getSize());
820        if (file.getHasCrc()) {
821            fileStream = new CRC32VerifyingInputStream(fileStream, file.getSize(), file.getCrcValue());
822        }
823
824        deferredBlockStreams.add(fileStream);
825    }
826
827    private void calculateStreamMap(final Archive archive) throws IOException {
828        int nextFolderPackStreamIndex = 0;
829        final int numFolders = archive.folders != null ? archive.folders.length : 0;
830        final int[] folderFirstPackStreamIndex = new int[numFolders];
831        for (int i = 0; i < numFolders; i++) {
832            folderFirstPackStreamIndex[i] = nextFolderPackStreamIndex;
833            nextFolderPackStreamIndex += archive.folders[i].packedStreams.length;
834        }
835        long nextPackStreamOffset = 0;
836        final int numPackSizes = archive.packSizes.length;
837        final long[] packStreamOffsets = new long[numPackSizes];
838        for (int i = 0; i < numPackSizes; i++) {
839            packStreamOffsets[i] = nextPackStreamOffset;
840            nextPackStreamOffset += archive.packSizes[i];
841        }
842        final int[] folderFirstFileIndex = new int[numFolders];
843        final int[] fileFolderIndex = new int[archive.files.length];
844        int nextFolderIndex = 0;
845        int nextFolderUnpackStreamIndex = 0;
846        for (int i = 0; i < archive.files.length; i++) {
847            if (!archive.files[i].hasStream() && nextFolderUnpackStreamIndex == 0) {
848                fileFolderIndex[i] = -1;
849                continue;
850            }
851            if (nextFolderUnpackStreamIndex == 0) {
852                for (; nextFolderIndex < archive.folders.length; ++nextFolderIndex) {
853                    folderFirstFileIndex[nextFolderIndex] = i;
854                    if (archive.folders[nextFolderIndex].numUnpackSubStreams > 0) {
855                        break;
856                    }
857                }
858                if (nextFolderIndex >= archive.folders.length) {
859                    throw new IOException("Too few folders in archive");
860                }
861            }
862            fileFolderIndex[i] = nextFolderIndex;
863            if (!archive.files[i].hasStream()) {
864                continue;
865            }
866            ++nextFolderUnpackStreamIndex;
867            if (nextFolderUnpackStreamIndex >= archive.folders[nextFolderIndex].numUnpackSubStreams) {
868                ++nextFolderIndex;
869                nextFolderUnpackStreamIndex = 0;
870            }
871        }
872        archive.streamMap = new StreamMap(folderFirstPackStreamIndex, packStreamOffsets, folderFirstFileIndex, fileFolderIndex);
873    }
874
875    private void checkEntryIsInitialized(final Map<Integer, SevenZArchiveEntry> archiveEntries, final int index) {
876        archiveEntries.computeIfAbsent(index, i -> new SevenZArchiveEntry());
877    }
878
879    /**
880     * Closes the archive.
881     *
882     * @throws IOException if closing the file fails
883     */
884    @Override
885    public void close() throws IOException {
886        if (channel != null) {
887            try {
888                channel.close();
889            } finally {
890                channel = null;
891                if (password != null) {
892                    Arrays.fill(password, (byte) 0);
893                }
894                password = null;
895            }
896        }
897    }
898
899    private InputStream getCurrentStream() throws IOException {
900        if (archive.files[currentEntryIndex].getSize() == 0) {
901            return new ByteArrayInputStream(ByteUtils.EMPTY_BYTE_ARRAY);
902        }
903        if (deferredBlockStreams.isEmpty()) {
904            throw new IllegalStateException("No current 7z entry (call getNextEntry() first).");
905        }
906
907        while (deferredBlockStreams.size() > 1) {
908            // In solid compression mode we need to decompress all leading folder'
909            // streams to get access to an entry. We defer this until really needed
910            // so that entire blocks can be skipped without wasting time for decompression.
911            try (InputStream stream = deferredBlockStreams.remove(0)) {
912                org.apache.commons.io.IOUtils.skip(stream, Long.MAX_VALUE);
913            }
914            compressedBytesReadFromCurrentEntry = 0;
915        }
916
917        return deferredBlockStreams.get(0);
918    }
919
920    /**
921     * Gets a default file name from the archive name - if known.
922     * <p>
923     * This implements the same heuristics the 7z tools use. In 7z's case if an archive contains entries without a name - i.e.
924     * {@link SevenZArchiveEntry#getName} returns {@code null} - then its command line and GUI tools will use this default name when extracting the entries.
925     * </p>
926     *
927     * @return null if the name of the archive is unknown. Otherwise, if the name of the archive has got any extension, it is stripped and the remainder
928     *         returned. Finally, if the name of the archive hasn't got any extension, then a {@code ~} character is appended to the archive name.
929     * @since 1.19
930     */
931    public String getDefaultName() {
932        if (DEFAULT_FILE_NAME.equals(fileName) || fileName == null) {
933            return null;
934        }
935
936        final String lastSegment = new File(fileName).getName();
937        final int dotPos = lastSegment.lastIndexOf(".");
938        if (dotPos > 0) { // if the file starts with a dot then this is not an extension
939            return lastSegment.substring(0, dotPos);
940        }
941        return lastSegment + "~";
942    }
943
944    /**
945     * Gets a copy of meta-data of all archive entries.
946     * <p>
947     * This method only provides meta-data, the entries can not be used to read the contents, you still need to process all entries in order using
948     * {@link #getNextEntry} for that.
949     * </p>
950     * <p>
951     * The content methods are only available for entries that have already been reached via {@link #getNextEntry}.
952     * </p>
953     *
954     * @return a copy of meta-data of all archive entries.
955     * @since 1.11
956     */
957    public Iterable<SevenZArchiveEntry> getEntries() {
958        return new ArrayList<>(Arrays.asList(archive.files));
959    }
960
961    /**
962     * Gets an InputStream for reading the contents of the given entry.
963     * <p>
964     * For archives using solid compression randomly accessing entries will be significantly slower than reading the archive sequentially.
965     * </p>
966     *
967     * @param entry the entry to get the stream for.
968     * @return a stream to read the entry from.
969     * @throws IOException if unable to create an input stream from the entry
970     * @since 1.20
971     */
972    public InputStream getInputStream(final SevenZArchiveEntry entry) throws IOException {
973        int entryIndex = -1;
974        for (int i = 0; i < this.archive.files.length; i++) {
975            if (entry == this.archive.files[i]) {
976                entryIndex = i;
977                break;
978            }
979        }
980
981        if (entryIndex < 0) {
982            throw new IllegalArgumentException("Can not find " + entry.getName() + " in " + this.fileName);
983        }
984
985        buildDecodingStream(entryIndex, true);
986        currentEntryIndex = entryIndex;
987        currentFolderIndex = archive.streamMap.fileFolderIndex[entryIndex];
988        return getCurrentStream();
989    }
990
991    /**
992     * Gets the next Archive Entry in this archive.
993     *
994     * @return the next entry, or {@code null} if there are no more entries
995     * @throws IOException if the next entry could not be read
996     */
997    public SevenZArchiveEntry getNextEntry() throws IOException {
998        if (currentEntryIndex >= archive.files.length - 1) {
999            return null;
1000        }
1001        ++currentEntryIndex;
1002        final SevenZArchiveEntry entry = archive.files[currentEntryIndex];
1003        if (entry.getName() == null && useDefaultNameForUnnamedEntries) {
1004            entry.setName(getDefaultName());
1005        }
1006        buildDecodingStream(currentEntryIndex, false);
1007        uncompressedBytesReadFromCurrentEntry = compressedBytesReadFromCurrentEntry = 0;
1008        return entry;
1009    }
1010
1011    /**
1012     * Gets statistics for bytes read from the current entry.
1013     *
1014     * @return statistics for bytes read from the current entry
1015     * @since 1.17
1016     */
1017    public InputStreamStatistics getStatisticsForCurrentEntry() {
1018        return new InputStreamStatistics() {
1019            @Override
1020            public long getCompressedCount() {
1021                return compressedBytesReadFromCurrentEntry;
1022            }
1023
1024            @Override
1025            public long getUncompressedCount() {
1026                return uncompressedBytesReadFromCurrentEntry;
1027            }
1028        };
1029    }
1030
1031    /**
1032     * Tests if any data of current entry has been read or not. This is achieved by comparing the bytes remaining to read and the size of the file.
1033     *
1034     * @return true if any data of current entry has been read
1035     * @since 1.21
1036     */
1037    private boolean hasCurrentEntryBeenRead() {
1038        boolean hasCurrentEntryBeenRead = false;
1039        if (!deferredBlockStreams.isEmpty()) {
1040            final InputStream currentEntryInputStream = deferredBlockStreams.get(deferredBlockStreams.size() - 1);
1041            // get the bytes remaining to read, and compare it with the size of
1042            // the file to figure out if the file has been read
1043            if (currentEntryInputStream instanceof CRC32VerifyingInputStream) {
1044                hasCurrentEntryBeenRead = ((CRC32VerifyingInputStream) currentEntryInputStream).getBytesRemaining() != archive.files[currentEntryIndex]
1045                        .getSize();
1046            }
1047
1048            if (currentEntryInputStream instanceof BoundedInputStream) {
1049                hasCurrentEntryBeenRead = ((BoundedInputStream) currentEntryInputStream).getBytesRemaining() != archive.files[currentEntryIndex].getSize();
1050            }
1051        }
1052        return hasCurrentEntryBeenRead;
1053    }
1054
1055    private Archive initializeArchive(final StartHeader startHeader, final byte[] password, final boolean verifyCrc) throws IOException {
1056        assertFitsIntoNonNegativeInt("nextHeaderSize", startHeader.nextHeaderSize);
1057        final int nextHeaderSizeInt = (int) startHeader.nextHeaderSize;
1058        channel.position(SIGNATURE_HEADER_SIZE + startHeader.nextHeaderOffset);
1059        if (verifyCrc) {
1060            final long position = channel.position();
1061            final CheckedInputStream cis = new CheckedInputStream(Channels.newInputStream(channel), new CRC32());
1062            if (cis.skip(nextHeaderSizeInt) != nextHeaderSizeInt) {
1063                throw new IOException("Problem computing NextHeader CRC-32");
1064            }
1065            if (startHeader.nextHeaderCrc != cis.getChecksum().getValue()) {
1066                throw new IOException("NextHeader CRC-32 mismatch");
1067            }
1068            channel.position(position);
1069        }
1070        Archive archive = new Archive();
1071        ByteBuffer buf = ByteBuffer.allocate(nextHeaderSizeInt).order(ByteOrder.LITTLE_ENDIAN);
1072        readFully(buf);
1073        int nid = getUnsignedByte(buf);
1074        if (nid == NID.kEncodedHeader) {
1075            buf = readEncodedHeader(buf, archive, password);
1076            // Archive gets rebuilt with the new header
1077            archive = new Archive();
1078            nid = getUnsignedByte(buf);
1079        }
1080        if (nid != NID.kHeader) {
1081            throw new IOException("Broken or unsupported archive: no Header");
1082        }
1083        readHeader(buf, archive);
1084        archive.subStreamsInfo = null;
1085        return archive;
1086    }
1087
1088    /**
1089     * Reads a byte of data.
1090     *
1091     * @return the byte read, or -1 if end of input is reached
1092     * @throws IOException if an I/O error has occurred
1093     */
1094    public int read() throws IOException {
1095        final int b = getCurrentStream().read();
1096        if (b >= 0) {
1097            uncompressedBytesReadFromCurrentEntry++;
1098        }
1099        return b;
1100    }
1101
1102    /**
1103     * Reads data into an array of bytes.
1104     *
1105     * @param b the array to write data to
1106     * @return the number of bytes read, or -1 if end of input is reached
1107     * @throws IOException if an I/O error has occurred
1108     */
1109    public int read(final byte[] b) throws IOException {
1110        return read(b, 0, b.length);
1111    }
1112
1113    /**
1114     * Reads data into an array of bytes.
1115     *
1116     * @param b   the array to write data to
1117     * @param off offset into the buffer to start filling at
1118     * @param len of bytes to read
1119     * @return the number of bytes read, or -1 if end of input is reached
1120     * @throws IOException if an I/O error has occurred
1121     */
1122    public int read(final byte[] b, final int off, final int len) throws IOException {
1123        if (len == 0) {
1124            return 0;
1125        }
1126        final int cnt = getCurrentStream().read(b, off, len);
1127        if (cnt > 0) {
1128            uncompressedBytesReadFromCurrentEntry += cnt;
1129        }
1130        return cnt;
1131    }
1132
1133    private BitSet readAllOrBits(final ByteBuffer header, final int size) throws IOException {
1134        final int areAllDefined = getUnsignedByte(header);
1135        final BitSet bits;
1136        if (areAllDefined != 0) {
1137            bits = new BitSet(size);
1138            for (int i = 0; i < size; i++) {
1139                bits.set(i, true);
1140            }
1141        } else {
1142            bits = readBits(header, size);
1143        }
1144        return bits;
1145    }
1146
1147    private void readArchiveProperties(final ByteBuffer input) throws IOException {
1148        // FIXME: the reference implementation just throws them away?
1149        int nid = getUnsignedByte(input);
1150        while (nid != NID.kEnd) {
1151            final long propertySize = readUint64(input);
1152            final byte[] property = new byte[(int) propertySize];
1153            get(input, property);
1154            nid = getUnsignedByte(input);
1155        }
1156    }
1157
1158    private BitSet readBits(final ByteBuffer header, final int size) throws IOException {
1159        final BitSet bits = new BitSet(size);
1160        int mask = 0;
1161        int cache = 0;
1162        for (int i = 0; i < size; i++) {
1163            if (mask == 0) {
1164                mask = 0x80;
1165                cache = getUnsignedByte(header);
1166            }
1167            bits.set(i, (cache & mask) != 0);
1168            mask >>>= 1;
1169        }
1170        return bits;
1171    }
1172
1173    private ByteBuffer readEncodedHeader(final ByteBuffer header, final Archive archive, final byte[] password) throws IOException {
1174        final int pos = header.position();
1175        final ArchiveStatistics stats = new ArchiveStatistics();
1176        sanityCheckStreamsInfo(header, stats);
1177        stats.assertValidity(maxMemoryLimitKb);
1178        header.position(pos);
1179
1180        readStreamsInfo(header, archive);
1181
1182        if (archive.folders == null || archive.folders.length == 0) {
1183            throw new IOException("no folders, can't read encoded header");
1184        }
1185        if (archive.packSizes == null || archive.packSizes.length == 0) {
1186            throw new IOException("no packed streams, can't read encoded header");
1187        }
1188
1189        // FIXME: merge with buildDecodingStream()/buildDecoderStack() at some stage?
1190        final Folder folder = archive.folders[0];
1191        final int firstPackStreamIndex = 0;
1192        final long folderOffset = SIGNATURE_HEADER_SIZE + archive.packPos + 0;
1193
1194        channel.position(folderOffset);
1195        InputStream inputStreamStack = new BoundedSeekableByteChannelInputStream(channel, archive.packSizes[firstPackStreamIndex]);
1196        for (final Coder coder : folder.getOrderedCoders()) {
1197            if (coder.numInStreams != 1 || coder.numOutStreams != 1) {
1198                throw new IOException("Multi input/output stream coders are not yet supported");
1199            }
1200            inputStreamStack = Coders.addDecoder(fileName, inputStreamStack, // NOSONAR
1201                    folder.getUnpackSizeForCoder(coder), coder, password, maxMemoryLimitKb);
1202        }
1203        if (folder.hasCrc) {
1204            inputStreamStack = new CRC32VerifyingInputStream(inputStreamStack, folder.getUnpackSize(), folder.crc);
1205        }
1206        final int unpackSize = assertFitsIntoNonNegativeInt("unpackSize", folder.getUnpackSize());
1207        final byte[] nextHeader = IOUtils.readRange(inputStreamStack, unpackSize);
1208        if (nextHeader.length < unpackSize) {
1209            throw new IOException("premature end of stream");
1210        }
1211        inputStreamStack.close();
1212        return ByteBuffer.wrap(nextHeader).order(ByteOrder.LITTLE_ENDIAN);
1213    }
1214
1215    private void readFilesInfo(final ByteBuffer header, final Archive archive) throws IOException {
1216        final int numFilesInt = (int) readUint64(header);
1217        final Map<Integer, SevenZArchiveEntry> fileMap = new LinkedHashMap<>();
1218        BitSet isEmptyStream = null;
1219        BitSet isEmptyFile = null;
1220        BitSet isAnti = null;
1221        while (true) {
1222            final int propertyType = getUnsignedByte(header);
1223            if (propertyType == 0) {
1224                break;
1225            }
1226            final long size = readUint64(header);
1227            switch (propertyType) {
1228            case NID.kEmptyStream: {
1229                isEmptyStream = readBits(header, numFilesInt);
1230                break;
1231            }
1232            case NID.kEmptyFile: {
1233                isEmptyFile = readBits(header, isEmptyStream.cardinality());
1234                break;
1235            }
1236            case NID.kAnti: {
1237                isAnti = readBits(header, isEmptyStream.cardinality());
1238                break;
1239            }
1240            case NID.kName: {
1241                /* final int external = */ getUnsignedByte(header);
1242                final byte[] names = new byte[(int) (size - 1)];
1243                final int namesLength = names.length;
1244                get(header, names);
1245                int nextFile = 0;
1246                int nextName = 0;
1247                for (int i = 0; i < namesLength; i += 2) {
1248                    if (names[i] == 0 && names[i + 1] == 0) {
1249                        checkEntryIsInitialized(fileMap, nextFile);
1250                        fileMap.get(nextFile).setName(new String(names, nextName, i - nextName, UTF_16LE));
1251                        nextName = i + 2;
1252                        nextFile++;
1253                    }
1254                }
1255                if (nextName != namesLength || nextFile != numFilesInt) {
1256                    throw new IOException("Error parsing file names");
1257                }
1258                break;
1259            }
1260            case NID.kCTime: {
1261                final BitSet timesDefined = readAllOrBits(header, numFilesInt);
1262                /* final int external = */ getUnsignedByte(header);
1263                for (int i = 0; i < numFilesInt; i++) {
1264                    checkEntryIsInitialized(fileMap, i);
1265                    final SevenZArchiveEntry entryAtIndex = fileMap.get(i);
1266                    entryAtIndex.setHasCreationDate(timesDefined.get(i));
1267                    if (entryAtIndex.getHasCreationDate()) {
1268                        entryAtIndex.setCreationDate(getLong(header));
1269                    }
1270                }
1271                break;
1272            }
1273            case NID.kATime: {
1274                final BitSet timesDefined = readAllOrBits(header, numFilesInt);
1275                /* final int external = */ getUnsignedByte(header);
1276                for (int i = 0; i < numFilesInt; i++) {
1277                    checkEntryIsInitialized(fileMap, i);
1278                    final SevenZArchiveEntry entryAtIndex = fileMap.get(i);
1279                    entryAtIndex.setHasAccessDate(timesDefined.get(i));
1280                    if (entryAtIndex.getHasAccessDate()) {
1281                        entryAtIndex.setAccessDate(getLong(header));
1282                    }
1283                }
1284                break;
1285            }
1286            case NID.kMTime: {
1287                final BitSet timesDefined = readAllOrBits(header, numFilesInt);
1288                /* final int external = */ getUnsignedByte(header);
1289                for (int i = 0; i < numFilesInt; i++) {
1290                    checkEntryIsInitialized(fileMap, i);
1291                    final SevenZArchiveEntry entryAtIndex = fileMap.get(i);
1292                    entryAtIndex.setHasLastModifiedDate(timesDefined.get(i));
1293                    if (entryAtIndex.getHasLastModifiedDate()) {
1294                        entryAtIndex.setLastModifiedDate(getLong(header));
1295                    }
1296                }
1297                break;
1298            }
1299            case NID.kWinAttributes: {
1300                final BitSet attributesDefined = readAllOrBits(header, numFilesInt);
1301                /* final int external = */ getUnsignedByte(header);
1302                for (int i = 0; i < numFilesInt; i++) {
1303                    checkEntryIsInitialized(fileMap, i);
1304                    final SevenZArchiveEntry entryAtIndex = fileMap.get(i);
1305                    entryAtIndex.setHasWindowsAttributes(attributesDefined.get(i));
1306                    if (entryAtIndex.getHasWindowsAttributes()) {
1307                        entryAtIndex.setWindowsAttributes(getInt(header));
1308                    }
1309                }
1310                break;
1311            }
1312            case NID.kDummy: {
1313                // 7z 9.20 asserts the content is all zeros and ignores the property
1314                // Compress up to 1.8.1 would throw an exception, now we ignore it (see COMPRESS-287
1315
1316                skipBytesFully(header, size);
1317                break;
1318            }
1319
1320            default: {
1321                // Compress up to 1.8.1 would throw an exception, now we ignore it (see COMPRESS-287
1322                skipBytesFully(header, size);
1323                break;
1324            }
1325            }
1326        }
1327        int nonEmptyFileCounter = 0;
1328        int emptyFileCounter = 0;
1329        for (int i = 0; i < numFilesInt; i++) {
1330            final SevenZArchiveEntry entryAtIndex = fileMap.get(i);
1331            if (entryAtIndex == null) {
1332                continue;
1333            }
1334            entryAtIndex.setHasStream(isEmptyStream == null || !isEmptyStream.get(i));
1335            if (entryAtIndex.hasStream()) {
1336                if (archive.subStreamsInfo == null) {
1337                    throw new IOException("Archive contains file with streams but no subStreamsInfo");
1338                }
1339                entryAtIndex.setDirectory(false);
1340                entryAtIndex.setAntiItem(false);
1341                entryAtIndex.setHasCrc(archive.subStreamsInfo.hasCrc.get(nonEmptyFileCounter));
1342                entryAtIndex.setCrcValue(archive.subStreamsInfo.crcs[nonEmptyFileCounter]);
1343                entryAtIndex.setSize(archive.subStreamsInfo.unpackSizes[nonEmptyFileCounter]);
1344                if (entryAtIndex.getSize() < 0) {
1345                    throw new IOException("broken archive, entry with negative size");
1346                }
1347                ++nonEmptyFileCounter;
1348            } else {
1349                entryAtIndex.setDirectory(isEmptyFile == null || !isEmptyFile.get(emptyFileCounter));
1350                entryAtIndex.setAntiItem(isAnti != null && isAnti.get(emptyFileCounter));
1351                entryAtIndex.setHasCrc(false);
1352                entryAtIndex.setSize(0);
1353                ++emptyFileCounter;
1354            }
1355        }
1356        archive.files = fileMap.values().stream().filter(Objects::nonNull).toArray(SevenZArchiveEntry[]::new);
1357        calculateStreamMap(archive);
1358    }
1359
1360    private Folder readFolder(final ByteBuffer header) throws IOException {
1361        final Folder folder = new Folder();
1362
1363        final long numCoders = readUint64(header);
1364        final Coder[] coders = new Coder[(int) numCoders];
1365        long totalInStreams = 0;
1366        long totalOutStreams = 0;
1367        for (int i = 0; i < coders.length; i++) {
1368            final int bits = getUnsignedByte(header);
1369            final int idSize = bits & 0xf;
1370            final boolean isSimple = (bits & 0x10) == 0;
1371            final boolean hasAttributes = (bits & 0x20) != 0;
1372            final boolean moreAlternativeMethods = (bits & 0x80) != 0;
1373
1374            final byte[] decompressionMethodId = new byte[idSize];
1375            get(header, decompressionMethodId);
1376            final long numInStreams;
1377            final long numOutStreams;
1378            if (isSimple) {
1379                numInStreams = 1;
1380                numOutStreams = 1;
1381            } else {
1382                numInStreams = readUint64(header);
1383                numOutStreams = readUint64(header);
1384            }
1385            totalInStreams += numInStreams;
1386            totalOutStreams += numOutStreams;
1387            byte[] properties = null;
1388            if (hasAttributes) {
1389                final long propertiesSize = readUint64(header);
1390                properties = new byte[(int) propertiesSize];
1391                get(header, properties);
1392            }
1393            // would need to keep looping as above:
1394            if (moreAlternativeMethods) {
1395                throw new IOException("Alternative methods are unsupported, please report. " + // NOSONAR
1396                        "The reference implementation doesn't support them either.");
1397            }
1398            coders[i] = new Coder(decompressionMethodId, numInStreams, numOutStreams, properties);
1399        }
1400        folder.coders = coders;
1401        folder.totalInputStreams = totalInStreams;
1402        folder.totalOutputStreams = totalOutStreams;
1403
1404        final long numBindPairs = totalOutStreams - 1;
1405        final BindPair[] bindPairs = new BindPair[(int) numBindPairs];
1406        for (int i = 0; i < bindPairs.length; i++) {
1407            bindPairs[i] = new BindPair(readUint64(header), readUint64(header));
1408        }
1409        folder.bindPairs = bindPairs;
1410
1411        final long numPackedStreams = totalInStreams - numBindPairs;
1412        final long[] packedStreams = new long[(int) numPackedStreams];
1413        if (numPackedStreams == 1) {
1414            int i;
1415            for (i = 0; i < (int) totalInStreams; i++) {
1416                if (folder.findBindPairForInStream(i) < 0) {
1417                    break;
1418                }
1419            }
1420            packedStreams[0] = i;
1421        } else {
1422            for (int i = 0; i < (int) numPackedStreams; i++) {
1423                packedStreams[i] = readUint64(header);
1424            }
1425        }
1426        folder.packedStreams = packedStreams;
1427
1428        return folder;
1429    }
1430
1431    private void readFully(final ByteBuffer buf) throws IOException {
1432        buf.rewind();
1433        IOUtils.readFully(channel, buf);
1434        buf.flip();
1435    }
1436
1437    private void readHeader(final ByteBuffer header, final Archive archive) throws IOException {
1438        final int pos = header.position();
1439        final ArchiveStatistics stats = sanityCheckAndCollectStatistics(header);
1440        stats.assertValidity(maxMemoryLimitKb);
1441        header.position(pos);
1442
1443        int nid = getUnsignedByte(header);
1444
1445        if (nid == NID.kArchiveProperties) {
1446            readArchiveProperties(header);
1447            nid = getUnsignedByte(header);
1448        }
1449
1450        if (nid == NID.kAdditionalStreamsInfo) {
1451            throw new IOException("Additional streams unsupported");
1452            // nid = getUnsignedByte(header);
1453        }
1454
1455        if (nid == NID.kMainStreamsInfo) {
1456            readStreamsInfo(header, archive);
1457            nid = getUnsignedByte(header);
1458        }
1459
1460        if (nid == NID.kFilesInfo) {
1461            readFilesInfo(header, archive);
1462            nid = getUnsignedByte(header);
1463        }
1464    }
1465
1466    private Archive readHeaders(final byte[] password) throws IOException {
1467        final ByteBuffer buf = ByteBuffer.allocate(12 /* signature + 2 bytes version + 4 bytes CRC */).order(ByteOrder.LITTLE_ENDIAN);
1468        readFully(buf);
1469        final byte[] signature = new byte[6];
1470        buf.get(signature);
1471        if (!Arrays.equals(signature, sevenZSignature)) {
1472            throw new IOException("Bad 7z signature");
1473        }
1474        // 7zFormat.txt has it wrong - it's first major then minor
1475        final byte archiveVersionMajor = buf.get();
1476        final byte archiveVersionMinor = buf.get();
1477        if (archiveVersionMajor != 0) {
1478            throw new IOException(String.format("Unsupported 7z version (%d,%d)", archiveVersionMajor, archiveVersionMinor));
1479        }
1480
1481        boolean headerLooksValid = false; // See https://www.7-zip.org/recover.html - "There is no correct End Header at the end of archive"
1482        final long startHeaderCrc = 0xffffFFFFL & buf.getInt();
1483        if (startHeaderCrc == 0) {
1484            // This is an indication of a corrupt header - peek the next 20 bytes
1485            final long currentPosition = channel.position();
1486            final ByteBuffer peekBuf = ByteBuffer.allocate(20);
1487            readFully(peekBuf);
1488            channel.position(currentPosition);
1489            // Header invalid if all data is 0
1490            while (peekBuf.hasRemaining()) {
1491                if (peekBuf.get() != 0) {
1492                    headerLooksValid = true;
1493                    break;
1494                }
1495            }
1496        } else {
1497            headerLooksValid = true;
1498        }
1499
1500        if (headerLooksValid) {
1501            return initializeArchive(readStartHeader(startHeaderCrc), password, true);
1502        }
1503        // No valid header found - probably first file of multipart archive was removed too early. Scan for end header.
1504        if (tryToRecoverBrokenArchives) {
1505            return tryToLocateEndHeader(password);
1506        }
1507        throw new IOException("archive seems to be invalid.\nYou may want to retry and enable the"
1508                + " tryToRecoverBrokenArchives if the archive could be a multi volume archive that has been closed" + " prematurely.");
1509    }
1510
1511    private void readPackInfo(final ByteBuffer header, final Archive archive) throws IOException {
1512        archive.packPos = readUint64(header);
1513        final int numPackStreamsInt = (int) readUint64(header);
1514        int nid = getUnsignedByte(header);
1515        if (nid == NID.kSize) {
1516            archive.packSizes = new long[numPackStreamsInt];
1517            for (int i = 0; i < archive.packSizes.length; i++) {
1518                archive.packSizes[i] = readUint64(header);
1519            }
1520            nid = getUnsignedByte(header);
1521        }
1522
1523        if (nid == NID.kCRC) {
1524            archive.packCrcsDefined = readAllOrBits(header, numPackStreamsInt);
1525            archive.packCrcs = new long[numPackStreamsInt];
1526            for (int i = 0; i < numPackStreamsInt; i++) {
1527                if (archive.packCrcsDefined.get(i)) {
1528                    archive.packCrcs[i] = 0xffffFFFFL & getInt(header);
1529                }
1530            }
1531
1532            nid = getUnsignedByte(header);
1533        }
1534    }
1535
1536    private StartHeader readStartHeader(final long startHeaderCrc) throws IOException {
1537        // using Stream rather than ByteBuffer for the benefit of the
1538        // built-in CRC check
1539        try (DataInputStream dataInputStream = new DataInputStream(
1540                new CRC32VerifyingInputStream(new BoundedSeekableByteChannelInputStream(channel, 20), 20, startHeaderCrc))) {
1541            final long nextHeaderOffset = Long.reverseBytes(dataInputStream.readLong());
1542            if (nextHeaderOffset < 0 || nextHeaderOffset + SIGNATURE_HEADER_SIZE > channel.size()) {
1543                throw new IOException("nextHeaderOffset is out of bounds");
1544            }
1545            final long nextHeaderSize = Long.reverseBytes(dataInputStream.readLong());
1546            final long nextHeaderEnd = nextHeaderOffset + nextHeaderSize;
1547            if (nextHeaderEnd < nextHeaderOffset || nextHeaderEnd + SIGNATURE_HEADER_SIZE > channel.size()) {
1548                throw new IOException("nextHeaderSize is out of bounds");
1549            }
1550            final long nextHeaderCrc = 0xffffFFFFL & Integer.reverseBytes(dataInputStream.readInt());
1551            return new StartHeader(nextHeaderOffset, nextHeaderSize, nextHeaderCrc);
1552        }
1553    }
1554
1555    private void readStreamsInfo(final ByteBuffer header, final Archive archive) throws IOException {
1556        int nid = getUnsignedByte(header);
1557
1558        if (nid == NID.kPackInfo) {
1559            readPackInfo(header, archive);
1560            nid = getUnsignedByte(header);
1561        }
1562
1563        if (nid == NID.kUnpackInfo) {
1564            readUnpackInfo(header, archive);
1565            nid = getUnsignedByte(header);
1566        } else {
1567            // archive without unpack/coders info
1568            archive.folders = Folder.EMPTY_FOLDER_ARRAY;
1569        }
1570
1571        if (nid == NID.kSubStreamsInfo) {
1572            readSubStreamsInfo(header, archive);
1573            nid = getUnsignedByte(header);
1574        }
1575    }
1576
1577    private void readSubStreamsInfo(final ByteBuffer header, final Archive archive) throws IOException {
1578        for (final Folder folder : archive.folders) {
1579            folder.numUnpackSubStreams = 1;
1580        }
1581        long unpackStreamsCount = archive.folders.length;
1582
1583        int nid = getUnsignedByte(header);
1584        if (nid == NID.kNumUnpackStream) {
1585            unpackStreamsCount = 0;
1586            for (final Folder folder : archive.folders) {
1587                final long numStreams = readUint64(header);
1588                folder.numUnpackSubStreams = (int) numStreams;
1589                unpackStreamsCount += numStreams;
1590            }
1591            nid = getUnsignedByte(header);
1592        }
1593
1594        final int totalUnpackStreams = (int) unpackStreamsCount;
1595        final SubStreamsInfo subStreamsInfo = new SubStreamsInfo(totalUnpackStreams);
1596        int nextUnpackStream = 0;
1597        for (final Folder folder : archive.folders) {
1598            if (folder.numUnpackSubStreams == 0) {
1599                continue;
1600            }
1601            long sum = 0;
1602            if (nid == NID.kSize) {
1603                for (int i = 0; i < folder.numUnpackSubStreams - 1; i++) {
1604                    final long size = readUint64(header);
1605                    subStreamsInfo.unpackSizes[nextUnpackStream++] = size;
1606                    sum += size;
1607                }
1608            }
1609            if (sum > folder.getUnpackSize()) {
1610                throw new IOException("sum of unpack sizes of folder exceeds total unpack size");
1611            }
1612            subStreamsInfo.unpackSizes[nextUnpackStream++] = folder.getUnpackSize() - sum;
1613        }
1614        if (nid == NID.kSize) {
1615            nid = getUnsignedByte(header);
1616        }
1617
1618        int numDigests = 0;
1619        for (final Folder folder : archive.folders) {
1620            if (folder.numUnpackSubStreams != 1 || !folder.hasCrc) {
1621                numDigests += folder.numUnpackSubStreams;
1622            }
1623        }
1624
1625        if (nid == NID.kCRC) {
1626            final BitSet hasMissingCrc = readAllOrBits(header, numDigests);
1627            final long[] missingCrcs = new long[numDigests];
1628            for (int i = 0; i < numDigests; i++) {
1629                if (hasMissingCrc.get(i)) {
1630                    missingCrcs[i] = 0xffffFFFFL & getInt(header);
1631                }
1632            }
1633            int nextCrc = 0;
1634            int nextMissingCrc = 0;
1635            for (final Folder folder : archive.folders) {
1636                if (folder.numUnpackSubStreams == 1 && folder.hasCrc) {
1637                    subStreamsInfo.hasCrc.set(nextCrc, true);
1638                    subStreamsInfo.crcs[nextCrc] = folder.crc;
1639                    ++nextCrc;
1640                } else {
1641                    for (int i = 0; i < folder.numUnpackSubStreams; i++) {
1642                        subStreamsInfo.hasCrc.set(nextCrc, hasMissingCrc.get(nextMissingCrc));
1643                        subStreamsInfo.crcs[nextCrc] = missingCrcs[nextMissingCrc];
1644                        ++nextCrc;
1645                        ++nextMissingCrc;
1646                    }
1647                }
1648            }
1649
1650            nid = getUnsignedByte(header);
1651        }
1652
1653        archive.subStreamsInfo = subStreamsInfo;
1654    }
1655
1656    private void readUnpackInfo(final ByteBuffer header, final Archive archive) throws IOException {
1657        int nid = getUnsignedByte(header);
1658        final int numFoldersInt = (int) readUint64(header);
1659        final Folder[] folders = new Folder[numFoldersInt];
1660        archive.folders = folders;
1661        /* final int external = */ getUnsignedByte(header);
1662        for (int i = 0; i < numFoldersInt; i++) {
1663            folders[i] = readFolder(header);
1664        }
1665
1666        nid = getUnsignedByte(header);
1667        for (final Folder folder : folders) {
1668            assertFitsIntoNonNegativeInt("totalOutputStreams", folder.totalOutputStreams);
1669            folder.unpackSizes = new long[(int) folder.totalOutputStreams];
1670            for (int i = 0; i < folder.totalOutputStreams; i++) {
1671                folder.unpackSizes[i] = readUint64(header);
1672            }
1673        }
1674
1675        nid = getUnsignedByte(header);
1676        if (nid == NID.kCRC) {
1677            final BitSet crcsDefined = readAllOrBits(header, numFoldersInt);
1678            for (int i = 0; i < numFoldersInt; i++) {
1679                if (crcsDefined.get(i)) {
1680                    folders[i].hasCrc = true;
1681                    folders[i].crc = 0xffffFFFFL & getInt(header);
1682                } else {
1683                    folders[i].hasCrc = false;
1684                }
1685            }
1686
1687            nid = getUnsignedByte(header);
1688        }
1689    }
1690
1691    /**
1692     * Discard any queued streams/ folder stream, and reopen the current folder input stream.
1693     *
1694     * @param folderIndex the index of the folder to reopen
1695     * @param file        the 7z entry to read
1696     * @throws IOException if exceptions occur when reading the 7z file
1697     */
1698    private void reopenFolderInputStream(final int folderIndex, final SevenZArchiveEntry file) throws IOException {
1699        deferredBlockStreams.clear();
1700        if (currentFolderInputStream != null) {
1701            currentFolderInputStream.close();
1702            currentFolderInputStream = null;
1703        }
1704        final Folder folder = archive.folders[folderIndex];
1705        final int firstPackStreamIndex = archive.streamMap.folderFirstPackStreamIndex[folderIndex];
1706        final long folderOffset = SIGNATURE_HEADER_SIZE + archive.packPos + archive.streamMap.packStreamOffsets[firstPackStreamIndex];
1707
1708        currentFolderInputStream = buildDecoderStack(folder, folderOffset, firstPackStreamIndex, file);
1709    }
1710
1711    private ArchiveStatistics sanityCheckAndCollectStatistics(final ByteBuffer header) throws IOException {
1712        final ArchiveStatistics stats = new ArchiveStatistics();
1713
1714        int nid = getUnsignedByte(header);
1715
1716        if (nid == NID.kArchiveProperties) {
1717            sanityCheckArchiveProperties(header);
1718            nid = getUnsignedByte(header);
1719        }
1720
1721        if (nid == NID.kAdditionalStreamsInfo) {
1722            throw new IOException("Additional streams unsupported");
1723            // nid = getUnsignedByte(header);
1724        }
1725
1726        if (nid == NID.kMainStreamsInfo) {
1727            sanityCheckStreamsInfo(header, stats);
1728            nid = getUnsignedByte(header);
1729        }
1730
1731        if (nid == NID.kFilesInfo) {
1732            sanityCheckFilesInfo(header, stats);
1733            nid = getUnsignedByte(header);
1734        }
1735
1736        if (nid != NID.kEnd) {
1737            throw new IOException("Badly terminated header, found " + nid);
1738        }
1739
1740        return stats;
1741    }
1742
1743    private void sanityCheckArchiveProperties(final ByteBuffer header) throws IOException {
1744        int nid = getUnsignedByte(header);
1745        while (nid != NID.kEnd) {
1746            final int propertySize = assertFitsIntoNonNegativeInt("propertySize", readUint64(header));
1747            if (skipBytesFully(header, propertySize) < propertySize) {
1748                throw new IOException("invalid property size");
1749            }
1750            nid = getUnsignedByte(header);
1751        }
1752    }
1753
1754    private void sanityCheckFilesInfo(final ByteBuffer header, final ArchiveStatistics stats) throws IOException {
1755        stats.numberOfEntries = assertFitsIntoNonNegativeInt("numFiles", readUint64(header));
1756
1757        int emptyStreams = -1;
1758        while (true) {
1759            final int propertyType = getUnsignedByte(header);
1760            if (propertyType == 0) {
1761                break;
1762            }
1763            final long size = readUint64(header);
1764            switch (propertyType) {
1765            case NID.kEmptyStream: {
1766                emptyStreams = readBits(header, stats.numberOfEntries).cardinality();
1767                break;
1768            }
1769            case NID.kEmptyFile: {
1770                if (emptyStreams == -1) {
1771                    throw new IOException("Header format error: kEmptyStream must appear before kEmptyFile");
1772                }
1773                readBits(header, emptyStreams);
1774                break;
1775            }
1776            case NID.kAnti: {
1777                if (emptyStreams == -1) {
1778                    throw new IOException("Header format error: kEmptyStream must appear before kAnti");
1779                }
1780                readBits(header, emptyStreams);
1781                break;
1782            }
1783            case NID.kName: {
1784                final int external = getUnsignedByte(header);
1785                if (external != 0) {
1786                    throw new IOException("Not implemented");
1787                }
1788                final int namesLength = assertFitsIntoNonNegativeInt("file names length", size - 1);
1789                if ((namesLength & 1) != 0) {
1790                    throw new IOException("File names length invalid");
1791                }
1792
1793                int filesSeen = 0;
1794                for (int i = 0; i < namesLength; i += 2) {
1795                    final char c = getChar(header);
1796                    if (c == 0) {
1797                        filesSeen++;
1798                    }
1799                }
1800                if (filesSeen != stats.numberOfEntries) {
1801                    throw new IOException("Invalid number of file names (" + filesSeen + " instead of " + stats.numberOfEntries + ")");
1802                }
1803                break;
1804            }
1805            case NID.kCTime: {
1806                final int timesDefined = readAllOrBits(header, stats.numberOfEntries).cardinality();
1807                final int external = getUnsignedByte(header);
1808                if (external != 0) {
1809                    throw new IOException("Not implemented");
1810                }
1811                if (skipBytesFully(header, 8 * timesDefined) < 8 * timesDefined) {
1812                    throw new IOException("invalid creation dates size");
1813                }
1814                break;
1815            }
1816            case NID.kATime: {
1817                final int timesDefined = readAllOrBits(header, stats.numberOfEntries).cardinality();
1818                final int external = getUnsignedByte(header);
1819                if (external != 0) {
1820                    throw new IOException("Not implemented");
1821                }
1822                if (skipBytesFully(header, 8 * timesDefined) < 8 * timesDefined) {
1823                    throw new IOException("invalid access dates size");
1824                }
1825                break;
1826            }
1827            case NID.kMTime: {
1828                final int timesDefined = readAllOrBits(header, stats.numberOfEntries).cardinality();
1829                final int external = getUnsignedByte(header);
1830                if (external != 0) {
1831                    throw new IOException("Not implemented");
1832                }
1833                if (skipBytesFully(header, 8 * timesDefined) < 8 * timesDefined) {
1834                    throw new IOException("invalid modification dates size");
1835                }
1836                break;
1837            }
1838            case NID.kWinAttributes: {
1839                final int attributesDefined = readAllOrBits(header, stats.numberOfEntries).cardinality();
1840                final int external = getUnsignedByte(header);
1841                if (external != 0) {
1842                    throw new IOException("Not implemented");
1843                }
1844                if (skipBytesFully(header, 4 * attributesDefined) < 4 * attributesDefined) {
1845                    throw new IOException("invalid windows attributes size");
1846                }
1847                break;
1848            }
1849            case NID.kStartPos: {
1850                throw new IOException("kStartPos is unsupported, please report");
1851            }
1852            case NID.kDummy: {
1853                // 7z 9.20 asserts the content is all zeros and ignores the property
1854                // Compress up to 1.8.1 would throw an exception, now we ignore it (see COMPRESS-287
1855
1856                if (skipBytesFully(header, size) < size) {
1857                    throw new IOException("Incomplete kDummy property");
1858                }
1859                break;
1860            }
1861
1862            default: {
1863                // Compress up to 1.8.1 would throw an exception, now we ignore it (see COMPRESS-287
1864                if (skipBytesFully(header, size) < size) {
1865                    throw new IOException("Incomplete property of type " + propertyType);
1866                }
1867                break;
1868            }
1869            }
1870        }
1871        stats.numberOfEntriesWithStream = stats.numberOfEntries - Math.max(emptyStreams, 0);
1872    }
1873
1874    private int sanityCheckFolder(final ByteBuffer header, final ArchiveStatistics stats) throws IOException {
1875
1876        final int numCoders = assertFitsIntoNonNegativeInt("numCoders", readUint64(header));
1877        if (numCoders == 0) {
1878            throw new IOException("Folder without coders");
1879        }
1880        stats.numberOfCoders += numCoders;
1881
1882        long totalOutStreams = 0;
1883        long totalInStreams = 0;
1884        for (int i = 0; i < numCoders; i++) {
1885            final int bits = getUnsignedByte(header);
1886            final int idSize = bits & 0xf;
1887            get(header, new byte[idSize]);
1888
1889            final boolean isSimple = (bits & 0x10) == 0;
1890            final boolean hasAttributes = (bits & 0x20) != 0;
1891            final boolean moreAlternativeMethods = (bits & 0x80) != 0;
1892            if (moreAlternativeMethods) {
1893                throw new IOException("Alternative methods are unsupported, please report. " + // NOSONAR
1894                        "The reference implementation doesn't support them either.");
1895            }
1896
1897            if (isSimple) {
1898                totalInStreams++;
1899                totalOutStreams++;
1900            } else {
1901                totalInStreams += assertFitsIntoNonNegativeInt("numInStreams", readUint64(header));
1902                totalOutStreams += assertFitsIntoNonNegativeInt("numOutStreams", readUint64(header));
1903            }
1904
1905            if (hasAttributes) {
1906                final int propertiesSize = assertFitsIntoNonNegativeInt("propertiesSize", readUint64(header));
1907                if (skipBytesFully(header, propertiesSize) < propertiesSize) {
1908                    throw new IOException("invalid propertiesSize in folder");
1909                }
1910            }
1911        }
1912        assertFitsIntoNonNegativeInt("totalInStreams", totalInStreams);
1913        assertFitsIntoNonNegativeInt("totalOutStreams", totalOutStreams);
1914        stats.numberOfOutStreams += totalOutStreams;
1915        stats.numberOfInStreams += totalInStreams;
1916
1917        if (totalOutStreams == 0) {
1918            throw new IOException("Total output streams can't be 0");
1919        }
1920
1921        final int numBindPairs = assertFitsIntoNonNegativeInt("numBindPairs", totalOutStreams - 1);
1922        if (totalInStreams < numBindPairs) {
1923            throw new IOException("Total input streams can't be less than the number of bind pairs");
1924        }
1925        final BitSet inStreamsBound = new BitSet((int) totalInStreams);
1926        for (int i = 0; i < numBindPairs; i++) {
1927            final int inIndex = assertFitsIntoNonNegativeInt("inIndex", readUint64(header));
1928            if (totalInStreams <= inIndex) {
1929                throw new IOException("inIndex is bigger than number of inStreams");
1930            }
1931            inStreamsBound.set(inIndex);
1932            final int outIndex = assertFitsIntoNonNegativeInt("outIndex", readUint64(header));
1933            if (totalOutStreams <= outIndex) {
1934                throw new IOException("outIndex is bigger than number of outStreams");
1935            }
1936        }
1937
1938        final int numPackedStreams = assertFitsIntoNonNegativeInt("numPackedStreams", totalInStreams - numBindPairs);
1939
1940        if (numPackedStreams == 1) {
1941            if (inStreamsBound.nextClearBit(0) == -1) {
1942                throw new IOException("Couldn't find stream's bind pair index");
1943            }
1944        } else {
1945            for (int i = 0; i < numPackedStreams; i++) {
1946                final int packedStreamIndex = assertFitsIntoNonNegativeInt("packedStreamIndex", readUint64(header));
1947                if (packedStreamIndex >= totalInStreams) {
1948                    throw new IOException("packedStreamIndex is bigger than number of totalInStreams");
1949                }
1950            }
1951        }
1952
1953        return (int) totalOutStreams;
1954    }
1955
1956    private void sanityCheckPackInfo(final ByteBuffer header, final ArchiveStatistics stats) throws IOException {
1957        final long packPos = readUint64(header);
1958        if (packPos < 0 || SIGNATURE_HEADER_SIZE + packPos > channel.size() || SIGNATURE_HEADER_SIZE + packPos < 0) {
1959            throw new IOException("packPos (" + packPos + ") is out of range");
1960        }
1961        final long numPackStreams = readUint64(header);
1962        stats.numberOfPackedStreams = assertFitsIntoNonNegativeInt("numPackStreams", numPackStreams);
1963        int nid = getUnsignedByte(header);
1964        if (nid == NID.kSize) {
1965            long totalPackSizes = 0;
1966            for (int i = 0; i < stats.numberOfPackedStreams; i++) {
1967                final long packSize = readUint64(header);
1968                totalPackSizes += packSize;
1969                final long endOfPackStreams = SIGNATURE_HEADER_SIZE + packPos + totalPackSizes;
1970                if (packSize < 0 || endOfPackStreams > channel.size() || endOfPackStreams < packPos) {
1971                    throw new IOException("packSize (" + packSize + ") is out of range");
1972                }
1973            }
1974            nid = getUnsignedByte(header);
1975        }
1976
1977        if (nid == NID.kCRC) {
1978            final int crcsDefined = readAllOrBits(header, stats.numberOfPackedStreams).cardinality();
1979            if (skipBytesFully(header, 4 * crcsDefined) < 4 * crcsDefined) {
1980                throw new IOException("invalid number of CRCs in PackInfo");
1981            }
1982            nid = getUnsignedByte(header);
1983        }
1984
1985        if (nid != NID.kEnd) {
1986            throw new IOException("Badly terminated PackInfo (" + nid + ")");
1987        }
1988    }
1989
1990    private void sanityCheckStreamsInfo(final ByteBuffer header, final ArchiveStatistics stats) throws IOException {
1991        int nid = getUnsignedByte(header);
1992
1993        if (nid == NID.kPackInfo) {
1994            sanityCheckPackInfo(header, stats);
1995            nid = getUnsignedByte(header);
1996        }
1997
1998        if (nid == NID.kUnpackInfo) {
1999            sanityCheckUnpackInfo(header, stats);
2000            nid = getUnsignedByte(header);
2001        }
2002
2003        if (nid == NID.kSubStreamsInfo) {
2004            sanityCheckSubStreamsInfo(header, stats);
2005            nid = getUnsignedByte(header);
2006        }
2007
2008        if (nid != NID.kEnd) {
2009            throw new IOException("Badly terminated StreamsInfo");
2010        }
2011    }
2012
2013    private void sanityCheckSubStreamsInfo(final ByteBuffer header, final ArchiveStatistics stats) throws IOException {
2014
2015        int nid = getUnsignedByte(header);
2016        final List<Integer> numUnpackSubStreamsPerFolder = new LinkedList<>();
2017        if (nid == NID.kNumUnpackStream) {
2018            for (int i = 0; i < stats.numberOfFolders; i++) {
2019                numUnpackSubStreamsPerFolder.add(assertFitsIntoNonNegativeInt("numStreams", readUint64(header)));
2020            }
2021            stats.numberOfUnpackSubStreams = numUnpackSubStreamsPerFolder.stream().mapToLong(Integer::longValue).sum();
2022            nid = getUnsignedByte(header);
2023        } else {
2024            stats.numberOfUnpackSubStreams = stats.numberOfFolders;
2025        }
2026
2027        assertFitsIntoNonNegativeInt("totalUnpackStreams", stats.numberOfUnpackSubStreams);
2028
2029        if (nid == NID.kSize) {
2030            for (final int numUnpackSubStreams : numUnpackSubStreamsPerFolder) {
2031                if (numUnpackSubStreams == 0) {
2032                    continue;
2033                }
2034                for (int i = 0; i < numUnpackSubStreams - 1; i++) {
2035                    final long size = readUint64(header);
2036                    if (size < 0) {
2037                        throw new IOException("negative unpackSize");
2038                    }
2039                }
2040            }
2041            nid = getUnsignedByte(header);
2042        }
2043
2044        int numDigests = 0;
2045        if (numUnpackSubStreamsPerFolder.isEmpty()) {
2046            numDigests = stats.folderHasCrc == null ? stats.numberOfFolders : stats.numberOfFolders - stats.folderHasCrc.cardinality();
2047        } else {
2048            int folderIdx = 0;
2049            for (final int numUnpackSubStreams : numUnpackSubStreamsPerFolder) {
2050                if (numUnpackSubStreams != 1 || stats.folderHasCrc == null || !stats.folderHasCrc.get(folderIdx++)) {
2051                    numDigests += numUnpackSubStreams;
2052                }
2053            }
2054        }
2055
2056        if (nid == NID.kCRC) {
2057            assertFitsIntoNonNegativeInt("numDigests", numDigests);
2058            final int missingCrcs = readAllOrBits(header, numDigests).cardinality();
2059            if (skipBytesFully(header, 4 * missingCrcs) < 4 * missingCrcs) {
2060                throw new IOException("invalid number of missing CRCs in SubStreamInfo");
2061            }
2062            nid = getUnsignedByte(header);
2063        }
2064
2065        if (nid != NID.kEnd) {
2066            throw new IOException("Badly terminated SubStreamsInfo");
2067        }
2068    }
2069
2070    private void sanityCheckUnpackInfo(final ByteBuffer header, final ArchiveStatistics stats) throws IOException {
2071        int nid = getUnsignedByte(header);
2072        if (nid != NID.kFolder) {
2073            throw new IOException("Expected kFolder, got " + nid);
2074        }
2075        final long numFolders = readUint64(header);
2076        stats.numberOfFolders = assertFitsIntoNonNegativeInt("numFolders", numFolders);
2077        final int external = getUnsignedByte(header);
2078        if (external != 0) {
2079            throw new IOException("External unsupported");
2080        }
2081
2082        final List<Integer> numberOfOutputStreamsPerFolder = new LinkedList<>();
2083        for (int i = 0; i < stats.numberOfFolders; i++) {
2084            numberOfOutputStreamsPerFolder.add(sanityCheckFolder(header, stats));
2085        }
2086
2087        final long totalNumberOfBindPairs = stats.numberOfOutStreams - stats.numberOfFolders;
2088        final long packedStreamsRequiredByFolders = stats.numberOfInStreams - totalNumberOfBindPairs;
2089        if (packedStreamsRequiredByFolders < stats.numberOfPackedStreams) {
2090            throw new IOException("archive doesn't contain enough packed streams");
2091        }
2092
2093        nid = getUnsignedByte(header);
2094        if (nid != NID.kCodersUnpackSize) {
2095            throw new IOException("Expected kCodersUnpackSize, got " + nid);
2096        }
2097
2098        for (final int numberOfOutputStreams : numberOfOutputStreamsPerFolder) {
2099            for (int i = 0; i < numberOfOutputStreams; i++) {
2100                final long unpackSize = readUint64(header);
2101                if (unpackSize < 0) {
2102                    throw new IllegalArgumentException("negative unpackSize");
2103                }
2104            }
2105        }
2106
2107        nid = getUnsignedByte(header);
2108        if (nid == NID.kCRC) {
2109            stats.folderHasCrc = readAllOrBits(header, stats.numberOfFolders);
2110            final int crcsDefined = stats.folderHasCrc.cardinality();
2111            if (skipBytesFully(header, 4 * crcsDefined) < 4 * crcsDefined) {
2112                throw new IOException("invalid number of CRCs in UnpackInfo");
2113            }
2114            nid = getUnsignedByte(header);
2115        }
2116
2117        if (nid != NID.kEnd) {
2118            throw new IOException("Badly terminated UnpackInfo");
2119        }
2120    }
2121
2122    /**
2123     * Skips all the entries if needed. Entries need to be skipped when:
2124     * <p>
2125     * 1. it's a random access 2. one of these 2 condition is meet :
2126     * </p>
2127     * <p>
2128     * 2.1 currentEntryIndex != entryIndex : this means there are some entries to be skipped(currentEntryIndex < entryIndex) or the entry has already been
2129     * read(currentEntryIndex > entryIndex)
2130     * </p>
2131     * <p>
2132     * 2.2 currentEntryIndex == entryIndex && !hasCurrentEntryBeenRead: if the entry to be read is the current entry, but some data of it has been read before,
2133     * then we need to reopen the stream of the folder and skip all the entries before the current entries
2134     * </p>
2135     *
2136     * @param entryIndex     the entry to be read
2137     * @param isInSameFolder are the entry to be read and the current entry in the same folder
2138     * @param folderIndex    the index of the folder which contains the entry
2139     * @return true if there are entries actually skipped
2140     * @throws IOException there are exceptions when skipping entries
2141     * @since 1.21
2142     */
2143    private boolean skipEntriesWhenNeeded(final int entryIndex, final boolean isInSameFolder, final int folderIndex) throws IOException {
2144        final SevenZArchiveEntry file = archive.files[entryIndex];
2145        // if the entry to be read is the current entry, and the entry has not
2146        // been read yet, then there's nothing we need to do
2147        if (currentEntryIndex == entryIndex && !hasCurrentEntryBeenRead()) {
2148            return false;
2149        }
2150
2151        // 1. if currentEntryIndex < entryIndex :
2152        // this means there are some entries to be skipped(currentEntryIndex < entryIndex)
2153        // 2. if currentEntryIndex > entryIndex || (currentEntryIndex == entryIndex && hasCurrentEntryBeenRead) :
2154        // this means the entry has already been read before, and we need to reopen the
2155        // stream of the folder and skip all the entries before the current entries
2156        int filesToSkipStartIndex = archive.streamMap.folderFirstFileIndex[currentFolderIndex];
2157        if (isInSameFolder) {
2158            if (currentEntryIndex < entryIndex) {
2159                // the entries between filesToSkipStartIndex and currentEntryIndex had already been skipped
2160                filesToSkipStartIndex = currentEntryIndex + 1;
2161            } else {
2162                // the entry is in the same folder of current entry, but it has already been read before, we need to reset
2163                // the position of the currentFolderInputStream to the beginning of folder, and then skip the files
2164                // from the start entry of the folder again
2165                reopenFolderInputStream(folderIndex, file);
2166            }
2167        }
2168
2169        for (int i = filesToSkipStartIndex; i < entryIndex; i++) {
2170            final SevenZArchiveEntry fileToSkip = archive.files[i];
2171            InputStream fileStreamToSkip = new BoundedInputStream(currentFolderInputStream, fileToSkip.getSize());
2172            if (fileToSkip.getHasCrc()) {
2173                fileStreamToSkip = new CRC32VerifyingInputStream(fileStreamToSkip, fileToSkip.getSize(), fileToSkip.getCrcValue());
2174            }
2175            deferredBlockStreams.add(fileStreamToSkip);
2176
2177            // set the content methods as well, it equals to file.getContentMethods() because they are in same folder
2178            fileToSkip.setContentMethods(file.getContentMethods());
2179        }
2180        return true;
2181    }
2182
2183    @Override
2184    public String toString() {
2185        return archive.toString();
2186    }
2187
2188    private Archive tryToLocateEndHeader(final byte[] password) throws IOException {
2189        final ByteBuffer nidBuf = ByteBuffer.allocate(1);
2190        final long searchLimit = 1024L * 1024 * 1;
2191        // Main header, plus bytes that readStartHeader would read
2192        final long previousDataSize = channel.position() + 20;
2193        final long minPos;
2194        // Determine minimal position - can't start before current position
2195        if (channel.position() + searchLimit > channel.size()) {
2196            minPos = channel.position();
2197        } else {
2198            minPos = channel.size() - searchLimit;
2199        }
2200        long pos = channel.size() - 1;
2201        // Loop: Try from end of archive
2202        while (pos > minPos) {
2203            pos--;
2204            channel.position(pos);
2205            nidBuf.rewind();
2206            if (channel.read(nidBuf) < 1) {
2207                throw new EOFException();
2208            }
2209            final int nid = nidBuf.array()[0];
2210            // First indicator: Byte equals one of these header identifiers
2211            if (nid == NID.kEncodedHeader || nid == NID.kHeader) {
2212                try {
2213                    // Try to initialize Archive structure from here
2214                    final long nextHeaderOffset = pos - previousDataSize;
2215                    final long nextHeaderSize = channel.size() - pos;
2216                    final StartHeader startHeader = new StartHeader(nextHeaderOffset, nextHeaderSize, 0);
2217                    final Archive result = initializeArchive(startHeader, password, false);
2218                    // Sanity check: There must be some data...
2219                    if (result.packSizes.length > 0 && result.files.length > 0) {
2220                        return result;
2221                    }
2222                } catch (final Exception ignore) {
2223                    // Wrong guess...
2224                }
2225            }
2226        }
2227        throw new IOException("Start header corrupt and unable to guess end header");
2228    }
2229}