| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| */ |
| package org.apache.commons.compress.archivers.zip; |
| |
| import java.io.ByteArrayInputStream; |
| import java.io.ByteArrayOutputStream; |
| import java.io.EOFException; |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.io.PushbackInputStream; |
| import java.util.zip.CRC32; |
| import java.util.zip.DataFormatException; |
| import java.util.zip.Inflater; |
| import java.util.zip.ZipEntry; |
| import java.util.zip.ZipException; |
| |
| import org.apache.commons.compress.archivers.ArchiveEntry; |
| import org.apache.commons.compress.archivers.ArchiveInputStream; |
| |
| import static org.apache.commons.compress.archivers.zip.ZipConstants.DWORD; |
| import static org.apache.commons.compress.archivers.zip.ZipConstants.SHORT; |
| import static org.apache.commons.compress.archivers.zip.ZipConstants.WORD; |
| import static org.apache.commons.compress.archivers.zip.ZipConstants.ZIP64_MAGIC; |
| |
| /** |
| * Implements an input stream that can read Zip archives. |
| * |
| * <p>Note that {@link ZipArchiveEntry#getSize()} may return -1 if the |
| * DEFLATE algorithm is used, as the size information is not available |
| * from the header.</p> |
| * |
| * <p>The {@link ZipFile} class is preferred when reading from files.</p> |
| * |
| * <p>As of Apache Commons Compress it transparently supports Zip64 |
| * extensions and thus individual entries and archives larger than 4 |
| * GB or with more than 65536 entries.</p> |
| * |
| * @see ZipFile |
| * @NotThreadSafe |
| */ |
| public class ZipArchiveInputStream extends ArchiveInputStream { |
| |
| /** |
| * The zip encoding to use for filenames and the file comment. |
| */ |
| private final ZipEncoding zipEncoding; |
| |
| /** |
| * Whether to look for and use Unicode extra fields. |
| */ |
| private final boolean useUnicodeExtraFields; |
| |
| /** |
| * Wrapped stream, will always be a PushbackInputStream. |
| */ |
| private final InputStream in; |
| |
| /** |
| * Inflater used for all deflated entries. |
| */ |
| private final Inflater inf = new Inflater(true); |
| |
| /** |
| * Calculates checkusms for all entries. |
| */ |
| private final CRC32 crc = new CRC32(); |
| |
| /** |
| * Buffer used to read from the wrapped stream. |
| */ |
| private final Buffer buf = new Buffer(); |
| /** |
| * The entry that is currently being read. |
| */ |
| private CurrentEntry current = null; |
| /** |
| * Whether the stream has been closed. |
| */ |
| private boolean closed = false; |
| /** |
| * Whether the stream has reached the central directory - and thus |
| * found all entries. |
| */ |
| private boolean hitCentralDirectory = false; |
| /** |
| * When reading a stored entry that uses the data descriptor this |
| * stream has to read the full entry and caches it. This is the |
| * cache. |
| */ |
| private ByteArrayInputStream lastStoredEntry = null; |
| |
| /** |
| * Whether the stream will try to read STORED entries that use a |
| * data descriptor. |
| */ |
| private boolean allowStoredEntriesWithDataDescriptor = false; |
| |
| private static final int LFH_LEN = 30; |
| /* |
| local file header signature 4 bytes (0x04034b50) |
| version needed to extract 2 bytes |
| general purpose bit flag 2 bytes |
| compression method 2 bytes |
| last mod file time 2 bytes |
| last mod file date 2 bytes |
| crc-32 4 bytes |
| compressed size 4 bytes |
| uncompressed size 4 bytes |
| file name length 2 bytes |
| extra field length 2 bytes |
| */ |
| |
| private static final int CFH_LEN = 46; |
| /* |
| central file header signature 4 bytes (0x02014b50) |
| version made by 2 bytes |
| version needed to extract 2 bytes |
| general purpose bit flag 2 bytes |
| compression method 2 bytes |
| last mod file time 2 bytes |
| last mod file date 2 bytes |
| crc-32 4 bytes |
| compressed size 4 bytes |
| uncompressed size 4 bytes |
| file name length 2 bytes |
| extra field length 2 bytes |
| file comment length 2 bytes |
| disk number start 2 bytes |
| internal file attributes 2 bytes |
| external file attributes 4 bytes |
| relative offset of local header 4 bytes |
| */ |
| |
| private static final long TWO_EXP_32 = ZIP64_MAGIC + 1; |
| |
| // cached buffers - must only be used locally in the class (COMPRESS-172 - reduce garbage collection) |
| private final byte[] LFH_BUF = new byte[LFH_LEN]; |
| private final byte[] SKIP_BUF = new byte[1024]; |
| private final byte[] SHORT_BUF = new byte[SHORT]; |
| private final byte[] WORD_BUF = new byte[WORD]; |
| private final byte[] TWO_DWORD_BUF = new byte[2 * DWORD]; |
| |
| private int entriesRead = 0; |
| |
| public ZipArchiveInputStream(InputStream inputStream) { |
| this(inputStream, ZipEncodingHelper.UTF8); |
| } |
| |
| /** |
| * @param encoding the encoding to use for file names, use null |
| * for the platform's default encoding |
| * @since 1.5 |
| */ |
| public ZipArchiveInputStream(InputStream inputStream, String encoding) { |
| this(inputStream, encoding, true); |
| } |
| |
| /** |
| * @param encoding the encoding to use for file names, use null |
| * for the platform's default encoding |
| * @param useUnicodeExtraFields whether to use InfoZIP Unicode |
| * Extra Fields (if present) to set the file names. |
| */ |
| public ZipArchiveInputStream(InputStream inputStream, |
| String encoding, |
| boolean useUnicodeExtraFields) { |
| this(inputStream, encoding, useUnicodeExtraFields, false); |
| } |
| |
| /** |
| * @param encoding the encoding to use for file names, use null |
| * for the platform's default encoding |
| * @param useUnicodeExtraFields whether to use InfoZIP Unicode |
| * Extra Fields (if present) to set the file names. |
| * @param allowStoredEntriesWithDataDescriptor whether the stream |
| * will try to read STORED entries that use a data descriptor |
| * @since 1.1 |
| */ |
| public ZipArchiveInputStream(InputStream inputStream, |
| String encoding, |
| boolean useUnicodeExtraFields, |
| boolean allowStoredEntriesWithDataDescriptor) { |
| zipEncoding = ZipEncodingHelper.getZipEncoding(encoding); |
| this.useUnicodeExtraFields = useUnicodeExtraFields; |
| in = new PushbackInputStream(inputStream, buf.buf.length); |
| this.allowStoredEntriesWithDataDescriptor = |
| allowStoredEntriesWithDataDescriptor; |
| } |
| |
| public ZipArchiveEntry getNextZipEntry() throws IOException { |
| boolean firstEntry = true; |
| if (closed || hitCentralDirectory) { |
| return null; |
| } |
| if (current != null) { |
| closeEntry(); |
| firstEntry = false; |
| } |
| |
| try { |
| if (firstEntry) { |
| // split archives have a special signature before the |
| // first local file header - look for it and fail with |
| // the appropriate error message if this is a split |
| // archive. |
| readFirstLocalFileHeader(LFH_BUF); |
| } else { |
| readFully(LFH_BUF); |
| } |
| } catch (EOFException e) { |
| return null; |
| } |
| |
| ZipLong sig = new ZipLong(LFH_BUF); |
| if (sig.equals(ZipLong.CFH_SIG) || sig.equals(ZipLong.AED_SIG)) { |
| hitCentralDirectory = true; |
| skipRemainderOfArchive(); |
| } |
| if (!sig.equals(ZipLong.LFH_SIG)) { |
| return null; |
| } |
| |
| int off = WORD; |
| current = new CurrentEntry(); |
| |
| int versionMadeBy = ZipShort.getValue(LFH_BUF, off); |
| off += SHORT; |
| current.entry.setPlatform((versionMadeBy >> ZipFile.BYTE_SHIFT) |
| & ZipFile.NIBLET_MASK); |
| |
| final GeneralPurposeBit gpFlag = GeneralPurposeBit.parse(LFH_BUF, off); |
| final boolean hasUTF8Flag = gpFlag.usesUTF8ForNames(); |
| final ZipEncoding entryEncoding = |
| hasUTF8Flag ? ZipEncodingHelper.UTF8_ZIP_ENCODING : zipEncoding; |
| current.hasDataDescriptor = gpFlag.usesDataDescriptor(); |
| current.entry.setGeneralPurposeBit(gpFlag); |
| |
| off += SHORT; |
| |
| current.entry.setMethod(ZipShort.getValue(LFH_BUF, off)); |
| off += SHORT; |
| |
| long time = ZipUtil.dosToJavaTime(ZipLong.getValue(LFH_BUF, off)); |
| current.entry.setTime(time); |
| off += WORD; |
| |
| ZipLong size = null, cSize = null; |
| if (!current.hasDataDescriptor) { |
| current.entry.setCrc(ZipLong.getValue(LFH_BUF, off)); |
| off += WORD; |
| |
| cSize = new ZipLong(LFH_BUF, off); |
| off += WORD; |
| |
| size = new ZipLong(LFH_BUF, off); |
| off += WORD; |
| } else { |
| off += 3 * WORD; |
| } |
| |
| int fileNameLen = ZipShort.getValue(LFH_BUF, off); |
| |
| off += SHORT; |
| |
| int extraLen = ZipShort.getValue(LFH_BUF, off); |
| off += SHORT; |
| |
| byte[] fileName = new byte[fileNameLen]; |
| readFully(fileName); |
| current.entry.setName(entryEncoding.decode(fileName), fileName); |
| |
| byte[] extraData = new byte[extraLen]; |
| readFully(extraData); |
| current.entry.setExtra(extraData); |
| |
| if (!hasUTF8Flag && useUnicodeExtraFields) { |
| ZipUtil.setNameAndCommentFromExtraFields(current.entry, fileName, |
| null); |
| } |
| |
| processZip64Extra(size, cSize); |
| entriesRead++; |
| return current.entry; |
| } |
| |
| /** |
| * Fills the given array with the first local file header and |
| * deals with splitting/spanning markers that may prefix the first |
| * LFH. |
| */ |
| private void readFirstLocalFileHeader(byte[] lfh) throws IOException { |
| readFully(lfh); |
| ZipLong sig = new ZipLong(lfh); |
| if (sig.equals(ZipLong.DD_SIG)) { |
| throw new |
| UnsupportedZipFeatureException(UnsupportedZipFeatureException |
| .Feature.SPLITTING); |
| } |
| if (sig.equals(ZipLong.SINGLE_SEGMENT_SPLIT_MARKER)) { |
| // The archive is not really split as only one segment was |
| // needed in the end. Just skip over the marker. |
| byte[] missedLfhBytes = new byte[4]; |
| readFully(missedLfhBytes); |
| System.arraycopy(lfh, 4, lfh, 0, LFH_LEN - 4); |
| System.arraycopy(missedLfhBytes, 0, lfh, LFH_LEN - 4, 4); |
| } |
| } |
| |
| /** |
| * Records whether a Zip64 extra is present and sets the size |
| * information from it if sizes are 0xFFFFFFFF and the entry |
| * doesn't use a data descriptor. |
| */ |
| private void processZip64Extra(ZipLong size, ZipLong cSize) { |
| Zip64ExtendedInformationExtraField z64 = |
| (Zip64ExtendedInformationExtraField) |
| current.entry.getExtraField(Zip64ExtendedInformationExtraField |
| .HEADER_ID); |
| current.usesZip64 = z64 != null; |
| if (!current.hasDataDescriptor) { |
| if (current.usesZip64 && (cSize.equals(ZipLong.ZIP64_MAGIC) |
| || size.equals(ZipLong.ZIP64_MAGIC)) |
| ) { |
| current.entry.setCompressedSize(z64.getCompressedSize() // z64 cannot be null here |
| .getLongValue()); |
| current.entry.setSize(z64.getSize().getLongValue()); |
| } else { |
| current.entry.setCompressedSize(cSize.getValue()); |
| current.entry.setSize(size.getValue()); |
| } |
| } |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public ArchiveEntry getNextEntry() throws IOException { |
| return getNextZipEntry(); |
| } |
| |
| /** |
| * Whether this class is able to read the given entry. |
| * |
| * <p>May return false if it is set up to use encryption or a |
| * compression method that hasn't been implemented yet.</p> |
| * @since 1.1 |
| */ |
| @Override |
| public boolean canReadEntryData(ArchiveEntry ae) { |
| if (ae instanceof ZipArchiveEntry) { |
| ZipArchiveEntry ze = (ZipArchiveEntry) ae; |
| return ZipUtil.canHandleEntryData(ze) |
| && supportsDataDescriptorFor(ze); |
| |
| } |
| return false; |
| } |
| |
| @Override |
| public int read(byte[] buffer, int start, int length) throws IOException { |
| if (closed) { |
| throw new IOException("The stream is closed"); |
| } |
| if (inf.finished() || current == null) { |
| return -1; |
| } |
| |
| // avoid int overflow, check null buffer |
| if (start <= buffer.length && length >= 0 && start >= 0 |
| && buffer.length - start >= length) { |
| ZipUtil.checkRequestedFeatures(current.entry); |
| if (!supportsDataDescriptorFor(current.entry)) { |
| throw new UnsupportedZipFeatureException(UnsupportedZipFeatureException |
| .Feature |
| .DATA_DESCRIPTOR, |
| current.entry); |
| } |
| |
| if (current.entry.getMethod() == ZipArchiveOutputStream.STORED) { |
| return readStored(buffer, start, length); |
| } |
| return readDeflated(buffer, start, length); |
| } |
| throw new ArrayIndexOutOfBoundsException(); |
| } |
| |
| /** |
| * Implementation of read for STORED entries. |
| */ |
| private int readStored(byte[] buffer, int start, int length) |
| throws IOException { |
| |
| if (current.hasDataDescriptor) { |
| if (lastStoredEntry == null) { |
| readStoredEntry(); |
| } |
| return lastStoredEntry.read(buffer, start, length); |
| } |
| |
| long csize = current.entry.getSize(); |
| if (current.bytesRead >= csize) { |
| return -1; |
| } |
| |
| if (buf.offsetInBuffer >= buf.lengthOfLastRead) { |
| buf.offsetInBuffer = 0; |
| if ((buf.lengthOfLastRead = in.read(buf.buf)) == -1) { |
| return -1; |
| } |
| count(buf.lengthOfLastRead); |
| current.bytesReadFromStream += buf.lengthOfLastRead; |
| } |
| |
| int toRead = length > buf.lengthOfLastRead |
| ? buf.lengthOfLastRead - buf.offsetInBuffer |
| : length; |
| if ((csize - current.bytesRead) < toRead) { |
| // if it is smaller than toRead then it fits into an int |
| toRead = (int) (csize - current.bytesRead); |
| } |
| System.arraycopy(buf.buf, buf.offsetInBuffer, buffer, start, toRead); |
| buf.offsetInBuffer += toRead; |
| current.bytesRead += toRead; |
| crc.update(buffer, start, toRead); |
| return toRead; |
| } |
| |
| /** |
| * Implementation of read for DEFLATED entries. |
| */ |
| private int readDeflated(byte[] buffer, int start, int length) |
| throws IOException { |
| int read = readFromInflater(buffer, start, length); |
| if (read == 0) { |
| if (inf.finished()) { |
| return -1; |
| } else if (inf.needsDictionary()) { |
| throw new ZipException("This archive needs a preset dictionary" |
| + " which is not supported by Commons" |
| + " Compress."); |
| } else if (buf.lengthOfLastRead == -1) { |
| throw new IOException("Truncated ZIP file"); |
| } |
| } |
| crc.update(buffer, start, read); |
| return read; |
| } |
| |
| /** |
| * Potentially reads more bytes to fill the inflater's buffer and |
| * reads from it. |
| */ |
| private int readFromInflater(byte[] buffer, int start, int length) |
| throws IOException { |
| int read = 0; |
| do { |
| if (inf.needsInput()) { |
| fill(); |
| if (buf.lengthOfLastRead > 0) { |
| current.bytesReadFromStream += buf.lengthOfLastRead; |
| } else { |
| break; |
| } |
| } |
| try { |
| read = inf.inflate(buffer, start, length); |
| } catch (DataFormatException e) { |
| throw new ZipException(e.getMessage()); |
| } |
| } while (read == 0 && inf.needsInput()); |
| return read; |
| } |
| |
| @Override |
| public void close() throws IOException { |
| if (!closed) { |
| closed = true; |
| in.close(); |
| inf.end(); |
| } |
| } |
| |
| /** |
| * Skips over and discards value bytes of data from this input |
| * stream. |
| * |
| * <p>This implementation may end up skipping over some smaller |
| * number of bytes, possibly 0, if and only if it reaches the end |
| * of the underlying stream.</p> |
| * |
| * <p>The actual number of bytes skipped is returned.</p> |
| * |
| * @param value the number of bytes to be skipped. |
| * @return the actual number of bytes skipped. |
| * @throws IOException - if an I/O error occurs. |
| * @throws IllegalArgumentException - if value is negative. |
| */ |
| @Override |
| public long skip(long value) throws IOException { |
| if (value >= 0) { |
| long skipped = 0; |
| while (skipped < value) { |
| long rem = value - skipped; |
| int x = read(SKIP_BUF, 0, |
| (int) (SKIP_BUF.length > rem ? rem |
| : SKIP_BUF.length)); |
| if (x == -1) { |
| return skipped; |
| } |
| skipped += x; |
| } |
| return skipped; |
| } |
| throw new IllegalArgumentException(); |
| } |
| |
| /** |
| * Checks if the signature matches what is expected for a zip file. |
| * Does not currently handle self-extracting zips which may have arbitrary |
| * leading content. |
| * |
| * @param signature |
| * the bytes to check |
| * @param length |
| * the number of bytes to check |
| * @return true, if this stream is a zip archive stream, false otherwise |
| */ |
| public static boolean matches(byte[] signature, int length) { |
| if (length < ZipArchiveOutputStream.LFH_SIG.length) { |
| return false; |
| } |
| |
| return checksig(signature, ZipArchiveOutputStream.LFH_SIG) // normal file |
| || checksig(signature, ZipArchiveOutputStream.EOCD_SIG) // empty zip |
| || checksig(signature, ZipArchiveOutputStream.DD_SIG) // split zip |
| || checksig(signature, |
| ZipLong.SINGLE_SEGMENT_SPLIT_MARKER.getBytes()); |
| } |
| |
| private static boolean checksig(byte[] signature, byte[] expected){ |
| for (int i = 0; i < expected.length; i++) { |
| if (signature[i] != expected[i]) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| /** |
| * Closes the current ZIP archive entry and positions the underlying |
| * stream to the beginning of the next entry. All per-entry variables |
| * and data structures are cleared. |
| * <p> |
| * If the compressed size of this entry is included in the entry header, |
| * then any outstanding bytes are simply skipped from the underlying |
| * stream without uncompressing them. This allows an entry to be safely |
| * closed even if the compression method is unsupported. |
| * <p> |
| * In case we don't know the compressed size of this entry or have |
| * already buffered too much data from the underlying stream to support |
| * uncompression, then the uncompression process is completed and the |
| * end position of the stream is adjusted based on the result of that |
| * process. |
| * |
| * @throws IOException if an error occurs |
| */ |
| private void closeEntry() throws IOException { |
| if (closed) { |
| throw new IOException("The stream is closed"); |
| } |
| if (current == null) { |
| return; |
| } |
| |
| // Ensure all entry bytes are read |
| if (current.bytesReadFromStream <= current.entry.getCompressedSize() |
| && !current.hasDataDescriptor) { |
| drainCurrentEntryData(); |
| } else { |
| skip(Long.MAX_VALUE); |
| |
| long inB = |
| current.entry.getMethod() == ZipArchiveOutputStream.DEFLATED |
| ? getBytesInflated() : current.bytesRead; |
| |
| // this is at most a single read() operation and can't |
| // exceed the range of int |
| int diff = (int) (current.bytesReadFromStream - inB); |
| |
| // Pushback any required bytes |
| if (diff > 0) { |
| pushback(buf.buf, buf.lengthOfLastRead - diff, diff); |
| } |
| } |
| |
| if (lastStoredEntry == null && current.hasDataDescriptor) { |
| readDataDescriptor(); |
| } |
| |
| inf.reset(); |
| buf.reset(); |
| crc.reset(); |
| current = null; |
| lastStoredEntry = null; |
| } |
| |
| /** |
| * Read all data of the current entry from the underlying stream |
| * that hasn't been read, yet. |
| */ |
| private void drainCurrentEntryData() throws IOException { |
| long remaining = current.entry.getCompressedSize() |
| - current.bytesReadFromStream; |
| while (remaining > 0) { |
| long n = in.read(buf.buf, 0, (int) Math.min(buf.buf.length, |
| remaining)); |
| if (n < 0) { |
| throw new EOFException( |
| "Truncated ZIP entry: " + current.entry.getName()); |
| } else { |
| count(n); |
| remaining -= n; |
| } |
| } |
| } |
| |
| /** |
| * Get the number of bytes Inflater has actually processed. |
| * |
| * <p>for Java < Java7 the getBytes* methods in |
| * Inflater/Deflater seem to return unsigned ints rather than |
| * longs that start over with 0 at 2^32.</p> |
| * |
| * <p>The stream knows how many bytes it has read, but not how |
| * many the Inflater actually consumed - it should be between the |
| * total number of bytes read for the entry and the total number |
| * minus the last read operation. Here we just try to make the |
| * value close enough to the bytes we've read by assuming the |
| * number of bytes consumed must be smaller than (or equal to) the |
| * number of bytes read but not smaller by more than 2^32.</p> |
| */ |
| private long getBytesInflated() { |
| long inB = inf.getBytesRead(); |
| if (current.bytesReadFromStream >= TWO_EXP_32) { |
| while (inB + TWO_EXP_32 <= current.bytesReadFromStream) { |
| inB += TWO_EXP_32; |
| } |
| } |
| return inB; |
| } |
| |
| private void fill() throws IOException { |
| if (closed) { |
| throw new IOException("The stream is closed"); |
| } |
| if ((buf.lengthOfLastRead = in.read(buf.buf)) > 0) { |
| count(buf.lengthOfLastRead); |
| inf.setInput(buf.buf, 0, buf.lengthOfLastRead); |
| } |
| } |
| |
| private void readFully(byte[] b) throws IOException { |
| int count = 0, x = 0; |
| while (count != b.length) { |
| count += x = in.read(b, count, b.length - count); |
| if (x == -1) { |
| throw new EOFException(); |
| } |
| count(x); |
| } |
| } |
| |
| private void readDataDescriptor() throws IOException { |
| readFully(WORD_BUF); |
| ZipLong val = new ZipLong(WORD_BUF); |
| if (ZipLong.DD_SIG.equals(val)) { |
| // data descriptor with signature, skip sig |
| readFully(WORD_BUF); |
| val = new ZipLong(WORD_BUF); |
| } |
| current.entry.setCrc(val.getValue()); |
| |
| // if there is a ZIP64 extra field, sizes are eight bytes |
| // each, otherwise four bytes each. Unfortunately some |
| // implementations - namely Java7 - use eight bytes without |
| // using a ZIP64 extra field - |
| // http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=7073588 |
| |
| // just read 16 bytes and check whether bytes nine to twelve |
| // look like one of the signatures of what could follow a data |
| // descriptor (ignoring archive decryption headers for now). |
| // If so, push back eight bytes and assume sizes are four |
| // bytes, otherwise sizes are eight bytes each. |
| readFully(TWO_DWORD_BUF); |
| ZipLong potentialSig = new ZipLong(TWO_DWORD_BUF, DWORD); |
| if (potentialSig.equals(ZipLong.CFH_SIG) |
| || potentialSig.equals(ZipLong.LFH_SIG)) { |
| pushback(TWO_DWORD_BUF, DWORD, DWORD); |
| current.entry.setCompressedSize(ZipLong.getValue(TWO_DWORD_BUF)); |
| current.entry.setSize(ZipLong.getValue(TWO_DWORD_BUF, WORD)); |
| } else { |
| current.entry |
| .setCompressedSize(ZipEightByteInteger |
| .getLongValue(TWO_DWORD_BUF)); |
| current.entry.setSize(ZipEightByteInteger |
| .getLongValue(TWO_DWORD_BUF, DWORD)); |
| } |
| } |
| |
| /** |
| * Whether this entry requires a data descriptor this library can work with. |
| * |
| * @return true if allowStoredEntriesWithDataDescriptor is true, |
| * the entry doesn't require any data descriptor or the method is |
| * DEFLATED. |
| */ |
| private boolean supportsDataDescriptorFor(ZipArchiveEntry entry) { |
| return allowStoredEntriesWithDataDescriptor || |
| !entry.getGeneralPurposeBit().usesDataDescriptor() |
| || entry.getMethod() == ZipEntry.DEFLATED; |
| } |
| |
| /** |
| * Caches a stored entry that uses the data descriptor. |
| * |
| * <ul> |
| * <li>Reads a stored entry until the signature of a local file |
| * header, central directory header or data descriptor has been |
| * found.</li> |
| * <li>Stores all entry data in lastStoredEntry.</p> |
| * <li>Rewinds the stream to position at the data |
| * descriptor.</li> |
| * <li>reads the data descriptor</li> |
| * </ul> |
| * |
| * <p>After calling this method the entry should know its size, |
| * the entry's data is cached and the stream is positioned at the |
| * next local file or central directory header.</p> |
| */ |
| private void readStoredEntry() throws IOException { |
| ByteArrayOutputStream bos = new ByteArrayOutputStream(); |
| int off = 0; |
| boolean done = false; |
| |
| // length of DD without signature |
| int ddLen = current.usesZip64 ? WORD + 2 * DWORD : 3 * WORD; |
| |
| while (!done) { |
| int r = in.read(buf.buf, off, |
| ZipArchiveOutputStream.BUFFER_SIZE - off); |
| if (r <= 0) { |
| // read the whole archive without ever finding a |
| // central directory |
| throw new IOException("Truncated ZIP file"); |
| } |
| if (r + off < 4) { |
| // buf is too small to check for a signature, loop |
| off += r; |
| continue; |
| } |
| |
| done = bufferContainsSignature(bos, off, r, ddLen); |
| if (!done) { |
| off = cacheBytesRead(bos, off, r, ddLen); |
| } |
| } |
| |
| byte[] b = bos.toByteArray(); |
| lastStoredEntry = new ByteArrayInputStream(b); |
| } |
| |
| private static final byte[] LFH = ZipLong.LFH_SIG.getBytes(); |
| private static final byte[] CFH = ZipLong.CFH_SIG.getBytes(); |
| private static final byte[] DD = ZipLong.DD_SIG.getBytes(); |
| |
| /** |
| * Checks whether the current buffer contains the signature of a |
| * "data decsriptor", "local file header" or |
| * "central directory entry". |
| * |
| * <p>If it contains such a signature, reads the data descriptor |
| * and positions the stream right after the data descriptor.</p> |
| */ |
| private boolean bufferContainsSignature(ByteArrayOutputStream bos, |
| int offset, int lastRead, |
| int expectedDDLen) |
| throws IOException { |
| boolean done = false; |
| int readTooMuch = 0; |
| for (int i = 0; !done && i < lastRead - 4; i++) { |
| if (buf.buf[i] == LFH[0] && buf.buf[i + 1] == LFH[1]) { |
| if ((buf.buf[i + 2] == LFH[2] && buf.buf[i + 3] == LFH[3]) |
| || (buf.buf[i] == CFH[2] && buf.buf[i + 3] == CFH[3])) { |
| // found a LFH or CFH: |
| readTooMuch = offset + lastRead - i - expectedDDLen; |
| done = true; |
| } |
| else if (buf.buf[i + 2] == DD[2] && buf.buf[i + 3] == DD[3]) { |
| // found DD: |
| readTooMuch = offset + lastRead - i; |
| done = true; |
| } |
| if (done) { |
| // * push back bytes read in excess as well as the data |
| // descriptor |
| // * copy the remaining bytes to cache |
| // * read data descriptor |
| pushback(buf.buf, offset + lastRead - readTooMuch, |
| readTooMuch); |
| bos.write(buf.buf, 0, i); |
| readDataDescriptor(); |
| } |
| } |
| } |
| return done; |
| } |
| |
| /** |
| * If the last read bytes could hold a data descriptor and an |
| * incomplete signature then save the last bytes to the front of |
| * the buffer and cache everything in front of the potential data |
| * descriptor into the given ByteArrayOutputStream. |
| * |
| * <p>Data descriptor plus incomplete signature (3 bytes in the |
| * worst case) can be 20 bytes max.</p> |
| */ |
| private int cacheBytesRead(ByteArrayOutputStream bos, int offset, |
| int lastRead, int expecteDDLen) { |
| final int cacheable = offset + lastRead - expecteDDLen - 3; |
| if (cacheable > 0) { |
| bos.write(buf.buf, 0, cacheable); |
| System.arraycopy(buf.buf, cacheable, buf.buf, 0, |
| expecteDDLen + 3); |
| offset = expecteDDLen + 3; |
| } else { |
| offset += lastRead; |
| } |
| return offset; |
| } |
| |
| private void pushback(byte[] buf, int offset, int length) |
| throws IOException { |
| ((PushbackInputStream) in).unread(buf, offset, length); |
| pushedBackBytes(length); |
| } |
| |
| // End of Central Directory Record |
| // end of central dir signature 4 bytes (0x06054b50) |
| // number of this disk 2 bytes |
| // number of the disk with the |
| // start of the central directory 2 bytes |
| // total number of entries in the |
| // central directory on this disk 2 bytes |
| // total number of entries in |
| // the central directory 2 bytes |
| // size of the central directory 4 bytes |
| // offset of start of central |
| // directory with respect to |
| // the starting disk number 4 bytes |
| // .ZIP file comment length 2 bytes |
| // .ZIP file comment (variable size) |
| // |
| |
| /** |
| * Reads the stream until it find the "End of central directory |
| * record" and consumes it as well. |
| */ |
| private void skipRemainderOfArchive() throws IOException { |
| // skip over central directory. One LFH has been read too much |
| // already. The calculation discounts file names and extra |
| // data so it will be too short. |
| realSkip(entriesRead * CFH_LEN - LFH_LEN); |
| findEocdRecord(); |
| realSkip(ZipFile.MIN_EOCD_SIZE |
| - WORD /* signature */ - SHORT /* comment len */); |
| readFully(SHORT_BUF); |
| // file comment |
| realSkip(ZipShort.getValue(SHORT_BUF)); |
| } |
| |
| /** |
| * Reads forward until the signature of the "End of central |
| * directory" recod is found. |
| */ |
| private void findEocdRecord() throws IOException { |
| int currentByte = -1; |
| boolean skipReadCall = false; |
| while (skipReadCall || (currentByte = readOneByte()) > -1) { |
| skipReadCall = false; |
| if (!isFirstByteOfEocdSig(currentByte)) { |
| continue; |
| } |
| currentByte = readOneByte(); |
| if (currentByte != ZipArchiveOutputStream.EOCD_SIG[1]) { |
| if (currentByte == -1) { |
| break; |
| } |
| skipReadCall = isFirstByteOfEocdSig(currentByte); |
| continue; |
| } |
| currentByte = readOneByte(); |
| if (currentByte != ZipArchiveOutputStream.EOCD_SIG[2]) { |
| if (currentByte == -1) { |
| break; |
| } |
| skipReadCall = isFirstByteOfEocdSig(currentByte); |
| continue; |
| } |
| currentByte = readOneByte(); |
| if (currentByte == -1 |
| || currentByte == ZipArchiveOutputStream.EOCD_SIG[3]) { |
| break; |
| } |
| skipReadCall = isFirstByteOfEocdSig(currentByte); |
| } |
| } |
| |
| /** |
| * Skips bytes by reading from the underlying stream rather than |
| * the (potentially inflating) archive stream - which {@link |
| * #skip} would do. |
| * |
| * Also updates bytes-read counter. |
| */ |
| private void realSkip(long value) throws IOException { |
| if (value >= 0) { |
| long skipped = 0; |
| while (skipped < value) { |
| long rem = value - skipped; |
| int x = in.read(SKIP_BUF, 0, |
| (int) (SKIP_BUF.length > rem ? rem |
| : SKIP_BUF.length)); |
| if (x == -1) { |
| return; |
| } |
| count(x); |
| skipped += x; |
| } |
| return; |
| } |
| throw new IllegalArgumentException(); |
| } |
| |
| /** |
| * Reads bytes by reading from the underlying stream rather than |
| * the (potentially inflating) archive stream - which {@link |
| * #read} would do. |
| * |
| * Also updates bytes-read counter. |
| */ |
| private int readOneByte() throws IOException { |
| int b = in.read(); |
| if (b != -1) { |
| count(1); |
| } |
| return b; |
| } |
| |
| private boolean isFirstByteOfEocdSig(int b) { |
| return b == ZipArchiveOutputStream.EOCD_SIG[0]; |
| } |
| |
| /** |
| * Structure collecting information for the entry that is |
| * currently being read. |
| */ |
| private static final class CurrentEntry { |
| /** |
| * Current ZIP entry. |
| */ |
| private final ZipArchiveEntry entry = new ZipArchiveEntry(); |
| /** |
| * Does the entry use a data descriptor? |
| */ |
| private boolean hasDataDescriptor; |
| /** |
| * Does the entry have a ZIP64 extended information extra field. |
| */ |
| private boolean usesZip64; |
| /** |
| * Number of bytes of entry content read by the client if the |
| * entry is STORED. |
| */ |
| private long bytesRead; |
| /** |
| * Number of bytes of entry content read so from the stream. |
| * |
| * <p>This may be more than the actual entry's length as some |
| * stuff gets buffered up and needs to be pushed back when the |
| * end of the entry has been reached.</p> |
| */ |
| private long bytesReadFromStream; |
| } |
| |
| /** |
| * Contains a temporary buffer used to read from the wrapped |
| * stream together with some information needed for internal |
| * housekeeping. |
| */ |
| private static final class Buffer { |
| /** |
| * Buffer used as temporary buffer when reading from the stream. |
| */ |
| private final byte[] buf = new byte[ZipArchiveOutputStream.BUFFER_SIZE]; |
| /** |
| * {@link #buf buf} may contain data the client hasnt read, yet, |
| * this is the first byte that hasn't been read so far. |
| */ |
| private int offsetInBuffer = 0; |
| /** |
| * Number of bytes read from the wrapped stream into {@link #buf |
| * buf} with the last read operation. |
| */ |
| private int lengthOfLastRead = 0; |
| /** |
| * Reset internal housekeeping. |
| */ |
| private void reset() { |
| offsetInBuffer = lengthOfLastRead = 0; |
| } |
| } |
| } |