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/*
* Copyright (c) 1995, 2021, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package java.util.zip;
import java.io.Closeable;
import java.io.InputStream;
import java.io.IOException;
import java.io.EOFException;
import java.io.File;
import java.io.RandomAccessFile;
import java.io.UncheckedIOException;
import java.lang.ref.Cleaner.Cleanable;
import java.nio.charset.CharacterCodingException;
import java.nio.charset.Charset;
import java.nio.file.InvalidPathException;
import java.nio.file.attribute.BasicFileAttributes;
import java.nio.file.Files;
import java.util.ArrayDeque;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Deque;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Locale;
import java.util.Objects;
import java.util.NoSuchElementException;
import java.util.Set;
import java.util.Spliterator;
import java.util.Spliterators;
import java.util.TreeSet;
import java.util.WeakHashMap;
import java.util.function.Consumer;
import java.util.function.IntFunction;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;
import java.util.stream.Stream;
import java.util.stream.StreamSupport;
import jdk.internal.access.JavaUtilZipFileAccess;
import jdk.internal.access.JavaUtilJarAccess;
import jdk.internal.access.SharedSecrets;
import jdk.internal.misc.VM;
import jdk.internal.perf.PerfCounter;
import jdk.internal.ref.CleanerFactory;
import jdk.internal.vm.annotation.Stable;
import sun.nio.cs.UTF_8;
import sun.security.util.SignatureFileVerifier;
import static java.util.zip.ZipConstants64.*;
import static java.util.zip.ZipUtils.*;
/**
* This class is used to read entries from a zip file.
*
* Unless otherwise noted, passing a {@code null} argument to a constructor
* or method in this class will cause a {@link NullPointerException} to be
* thrown.
*
* @apiNote
* To release resources used by this {@code ZipFile}, the {@link #close()} method
* should be called explicitly or by try-with-resources. Subclasses are responsible
* for the cleanup of resources acquired by the subclass. Subclasses that override
* {@link #finalize()} in order to perform cleanup should be modified to use alternative
* cleanup mechanisms such as {@link java.lang.ref.Cleaner} and remove the overriding
* {@code finalize} method.
*
* @author David Connelly
* @since 1.1
*/
public class ZipFile implements ZipConstants, Closeable {
private final String name; // zip file name
private volatile boolean closeRequested;
// The "resource" used by this zip file that needs to be
// cleaned after use.
// a) the input streams that need to be closed
// b) the list of cached Inflater objects
// c) the "native" source of this zip file.
private final @Stable CleanableResource res;
private static final int STORED = ZipEntry.STORED;
private static final int DEFLATED = ZipEntry.DEFLATED;
/**
* Mode flag to open a zip file for reading.
*/
public static final int OPEN_READ = 0x1;
/**
* Mode flag to open a zip file and mark it for deletion. The file will be
* deleted some time between the moment that it is opened and the moment
* that it is closed, but its contents will remain accessible via the
* {@code ZipFile} object until either the close method is invoked or the
* virtual machine exits.
*/
public static final int OPEN_DELETE = 0x4;
/**
* Opens a zip file for reading.
*
*
First, if there is a security manager, its {@code checkRead}
* method is called with the {@code name} argument as its argument
* to ensure the read is allowed.
*
*
The UTF-8 {@link java.nio.charset.Charset charset} is used to
* decode the entry names and comments.
*
* @param name the name of the zip file
* @throws ZipException if a ZIP format error has occurred
* @throws IOException if an I/O error has occurred
* @throws SecurityException if a security manager exists and its
* {@code checkRead} method doesn't allow read access to the file.
*
* @see SecurityManager#checkRead(java.lang.String)
*/
public ZipFile(String name) throws IOException {
this(new File(name), OPEN_READ);
}
/**
* Opens a new {@code ZipFile} to read from the specified
* {@code File} object in the specified mode. The mode argument
* must be either {@code OPEN_READ} or {@code OPEN_READ | OPEN_DELETE}.
*
*
First, if there is a security manager, its {@code checkRead}
* method is called with the {@code name} argument as its argument to
* ensure the read is allowed.
*
*
The UTF-8 {@link java.nio.charset.Charset charset} is used to
* decode the entry names and comments
*
* @param file the ZIP file to be opened for reading
* @param mode the mode in which the file is to be opened
* @throws ZipException if a ZIP format error has occurred
* @throws IOException if an I/O error has occurred
* @throws SecurityException if a security manager exists and
* its {@code checkRead} method
* doesn't allow read access to the file,
* or its {@code checkDelete} method doesn't allow deleting
* the file when the {@code OPEN_DELETE} flag is set.
* @throws IllegalArgumentException if the {@code mode} argument is invalid
* @see SecurityManager#checkRead(java.lang.String)
* @since 1.3
*/
public ZipFile(File file, int mode) throws IOException {
this(file, mode, UTF_8.INSTANCE);
}
/**
* Opens a ZIP file for reading given the specified File object.
*
*
The UTF-8 {@link java.nio.charset.Charset charset} is used to
* decode the entry names and comments.
*
* @param file the ZIP file to be opened for reading
* @throws ZipException if a ZIP format error has occurred
* @throws IOException if an I/O error has occurred
*/
public ZipFile(File file) throws ZipException, IOException {
this(file, OPEN_READ);
}
/**
* Opens a new {@code ZipFile} to read from the specified
* {@code File} object in the specified mode. The mode argument
* must be either {@code OPEN_READ} or {@code OPEN_READ | OPEN_DELETE}.
*
*
First, if there is a security manager, its {@code checkRead}
* method is called with the {@code name} argument as its argument to
* ensure the read is allowed.
*
* @param file the ZIP file to be opened for reading
* @param mode the mode in which the file is to be opened
* @param charset
* the {@linkplain java.nio.charset.Charset charset} to
* be used to decode the ZIP entry name and comment that are not
* encoded by using UTF-8 encoding (indicated by entry's general
* purpose flag).
*
* @throws ZipException if a ZIP format error has occurred
* @throws IOException if an I/O error has occurred
*
* @throws SecurityException
* if a security manager exists and its {@code checkRead}
* method doesn't allow read access to the file,or its
* {@code checkDelete} method doesn't allow deleting the
* file when the {@code OPEN_DELETE} flag is set
*
* @throws IllegalArgumentException if the {@code mode} argument is invalid
*
* @see SecurityManager#checkRead(java.lang.String)
*
* @since 1.7
*/
public ZipFile(File file, int mode, Charset charset) throws IOException
{
if (((mode & OPEN_READ) == 0) ||
((mode & ~(OPEN_READ | OPEN_DELETE)) != 0)) {
throw new IllegalArgumentException("Illegal mode: 0x"+
Integer.toHexString(mode));
}
String name = file.getPath();
file = new File(name);
@SuppressWarnings("removal")
SecurityManager sm = System.getSecurityManager();
if (sm != null) {
sm.checkRead(name);
if ((mode & OPEN_DELETE) != 0) {
sm.checkDelete(name);
}
}
Objects.requireNonNull(charset, "charset");
this.name = name;
long t0 = System.nanoTime();
this.res = new CleanableResource(this, ZipCoder.get(charset), file, mode);
PerfCounter.getZipFileOpenTime().addElapsedTimeFrom(t0);
PerfCounter.getZipFileCount().increment();
}
/**
* Opens a zip file for reading.
*
*
First, if there is a security manager, its {@code checkRead}
* method is called with the {@code name} argument as its argument
* to ensure the read is allowed.
*
* @param name the name of the zip file
* @param charset
* the {@linkplain java.nio.charset.Charset charset} to
* be used to decode the ZIP entry name and comment that are not
* encoded by using UTF-8 encoding (indicated by entry's general
* purpose flag).
*
* @throws ZipException if a ZIP format error has occurred
* @throws IOException if an I/O error has occurred
* @throws SecurityException
* if a security manager exists and its {@code checkRead}
* method doesn't allow read access to the file
*
* @see SecurityManager#checkRead(java.lang.String)
*
* @since 1.7
*/
public ZipFile(String name, Charset charset) throws IOException
{
this(new File(name), OPEN_READ, charset);
}
/**
* Opens a ZIP file for reading given the specified File object.
*
* @param file the ZIP file to be opened for reading
* @param charset
* The {@linkplain java.nio.charset.Charset charset} to be
* used to decode the ZIP entry name and comment (ignored if
* the language
* encoding bit of the ZIP entry's general purpose bit
* flag is set).
*
* @throws ZipException if a ZIP format error has occurred
* @throws IOException if an I/O error has occurred
*
* @since 1.7
*/
public ZipFile(File file, Charset charset) throws IOException
{
this(file, OPEN_READ, charset);
}
/**
* Returns the zip file comment, or null if none.
*
* @return the comment string for the zip file, or null if none
*
* @throws IllegalStateException if the zip file has been closed
*
* @since 1.7
*/
public String getComment() {
synchronized (this) {
ensureOpen();
if (res.zsrc.comment == null) {
return null;
}
return res.zsrc.zc.toString(res.zsrc.comment);
}
}
/**
* Returns the zip file entry for the specified name, or null
* if not found.
*
* @param name the name of the entry
* @return the zip file entry, or null if not found
* @throws IllegalStateException if the zip file has been closed
*/
public ZipEntry getEntry(String name) {
Objects.requireNonNull(name, "name");
ZipEntry entry = null;
synchronized (this) {
ensureOpen();
int pos = res.zsrc.getEntryPos(name, true);
if (pos != -1) {
entry = getZipEntry(name, pos);
}
}
return entry;
}
/**
* Returns an input stream for reading the contents of the specified
* zip file entry.
*
* Closing this ZIP file will, in turn, close all input streams that
* have been returned by invocations of this method.
*
* @param entry the zip file entry
* @return the input stream for reading the contents of the specified
* zip file entry.
* @throws ZipException if a ZIP format error has occurred
* @throws IOException if an I/O error has occurred
* @throws IllegalStateException if the zip file has been closed
*/
public InputStream getInputStream(ZipEntry entry) throws IOException {
Objects.requireNonNull(entry, "entry");
int pos;
ZipFileInputStream in;
Source zsrc = res.zsrc;
Set istreams = res.istreams;
synchronized (this) {
ensureOpen();
if (Objects.equals(lastEntryName, entry.name)) {
pos = lastEntryPos;
} else {
pos = zsrc.getEntryPos(entry.name, false);
}
if (pos == -1) {
return null;
}
in = new ZipFileInputStream(zsrc.cen, pos);
switch (CENHOW(zsrc.cen, pos)) {
case STORED:
synchronized (istreams) {
istreams.add(in);
}
return in;
case DEFLATED:
// Inflater likes a bit of slack
// MORE: Compute good size for inflater stream:
long size = CENLEN(zsrc.cen, pos) + 2;
if (size > 65536) {
size = 8192;
}
if (size <= 0) {
size = 4096;
}
InputStream is = new ZipFileInflaterInputStream(in, res, (int)size);
synchronized (istreams) {
istreams.add(is);
}
return is;
default:
throw new ZipException("invalid compression method");
}
}
}
private static class InflaterCleanupAction implements Runnable {
private final Inflater inf;
private final CleanableResource res;
InflaterCleanupAction(Inflater inf, CleanableResource res) {
this.inf = inf;
this.res = res;
}
@Override
public void run() {
res.releaseInflater(inf);
}
}
private class ZipFileInflaterInputStream extends InflaterInputStream {
private volatile boolean closeRequested;
private boolean eof = false;
private final Cleanable cleanable;
ZipFileInflaterInputStream(ZipFileInputStream zfin,
CleanableResource res, int size) {
this(zfin, res, res.getInflater(), size);
}
private ZipFileInflaterInputStream(ZipFileInputStream zfin,
CleanableResource res,
Inflater inf, int size) {
super(zfin, inf, size);
this.cleanable = CleanerFactory.cleaner().register(this,
new InflaterCleanupAction(inf, res));
}
public void close() throws IOException {
if (closeRequested)
return;
closeRequested = true;
super.close();
synchronized (res.istreams) {
res.istreams.remove(this);
}
cleanable.clean();
}
// Override fill() method to provide an extra "dummy" byte
// at the end of the input stream. This is required when
// using the "nowrap" Inflater option.
protected void fill() throws IOException {
if (eof) {
throw new EOFException("Unexpected end of ZLIB input stream");
}
len = in.read(buf, 0, buf.length);
if (len == -1) {
buf[0] = 0;
len = 1;
eof = true;
}
inf.setInput(buf, 0, len);
}
public int available() throws IOException {
if (closeRequested)
return 0;
long avail = ((ZipFileInputStream)in).size() - inf.getBytesWritten();
return (avail > (long) Integer.MAX_VALUE ?
Integer.MAX_VALUE : (int) avail);
}
}
/**
* Returns the path name of the ZIP file.
* @return the path name of the ZIP file
*/
public String getName() {
return name;
}
private class ZipEntryIterator
implements Enumeration, Iterator {
private int i = 0;
private final int entryCount;
public ZipEntryIterator(int entryCount) {
this.entryCount = entryCount;
}
@Override
public boolean hasMoreElements() {
return hasNext();
}
@Override
public boolean hasNext() {
return i < entryCount;
}
@Override
public T nextElement() {
return next();
}
@Override
@SuppressWarnings("unchecked")
public T next() {
synchronized (ZipFile.this) {
ensureOpen();
if (!hasNext()) {
throw new NoSuchElementException();
}
// each "entry" has 3 ints in table entries
return (T)getZipEntry(null, res.zsrc.getEntryPos(i++ * 3));
}
}
@Override
public Iterator asIterator() {
return this;
}
}
/**
* Returns an enumeration of the ZIP file entries.
* @return an enumeration of the ZIP file entries
* @throws IllegalStateException if the zip file has been closed
*/
public Enumeration entries() {
synchronized (this) {
ensureOpen();
return new ZipEntryIterator(res.zsrc.total);
}
}
private Enumeration jarEntries() {
synchronized (this) {
ensureOpen();
return new ZipEntryIterator(res.zsrc.total);
}
}
private class EntrySpliterator extends Spliterators.AbstractSpliterator {
private int index;
private final int fence;
private final IntFunction gen;
EntrySpliterator(int index, int fence, IntFunction gen) {
super((long)fence,
Spliterator.ORDERED | Spliterator.DISTINCT | Spliterator.IMMUTABLE |
Spliterator.NONNULL);
this.index = index;
this.fence = fence;
this.gen = gen;
}
@Override
public boolean tryAdvance(Consumer action) {
if (action == null)
throw new NullPointerException();
if (index >= 0 && index < fence) {
synchronized (ZipFile.this) {
ensureOpen();
action.accept(gen.apply(res.zsrc.getEntryPos(index++ * 3)));
}
return true;
}
return false;
}
}
/**
* Returns an ordered {@code Stream} over the ZIP file entries.
*
* Entries appear in the {@code Stream} in the order they appear in
* the central directory of the ZIP file.
*
* @return an ordered {@code Stream} of entries in this ZIP file
* @throws IllegalStateException if the zip file has been closed
* @since 1.8
*/
public Stream stream() {
synchronized (this) {
ensureOpen();
return StreamSupport.stream(new EntrySpliterator<>(0, res.zsrc.total,
pos -> getZipEntry(null, pos)), false);
}
}
private String getEntryName(int pos) {
byte[] cen = res.zsrc.cen;
int nlen = CENNAM(cen, pos);
ZipCoder zc = res.zsrc.zipCoderForPos(pos);
return zc.toString(cen, pos + CENHDR, nlen);
}
/*
* Returns an ordered {@code Stream} over the zip file entry names.
*
* Entry names appear in the {@code Stream} in the order they appear in
* the central directory of the ZIP file.
*
* @return an ordered {@code Stream} of entry names in this zip file
* @throws IllegalStateException if the zip file has been closed
* @since 10
*/
private Stream entryNameStream() {
synchronized (this) {
ensureOpen();
return StreamSupport.stream(
new EntrySpliterator<>(0, res.zsrc.total, this::getEntryName), false);
}
}
/*
* Returns an ordered {@code Stream} over the zip file entries.
*
* Entries appear in the {@code Stream} in the order they appear in
* the central directory of the jar file.
*
* @return an ordered {@code Stream} of entries in this zip file
* @throws IllegalStateException if the zip file has been closed
* @since 10
*/
private Stream jarStream() {
synchronized (this) {
ensureOpen();
return StreamSupport.stream(new EntrySpliterator<>(0, res.zsrc.total,
pos -> (JarEntry)getZipEntry(null, pos)), false);
}
}
private String lastEntryName;
private int lastEntryPos;
/* Check ensureOpen() before invoking this method */
private ZipEntry getZipEntry(String name, int pos) {
byte[] cen = res.zsrc.cen;
int nlen = CENNAM(cen, pos);
int elen = CENEXT(cen, pos);
int clen = CENCOM(cen, pos);
ZipCoder zc = res.zsrc.zipCoderForPos(pos);
if (name != null) {
// only need to check for mismatch of trailing slash
if (nlen > 0 &&
!name.isEmpty() &&
zc.hasTrailingSlash(cen, pos + CENHDR + nlen) &&
!name.endsWith("/"))
{
name += '/';
}
} else {
// invoked from iterator, use the entry name stored in cen
name = zc.toString(cen, pos + CENHDR, nlen);
}
ZipEntry e;
if (this instanceof JarFile) {
e = Source.JUJA.entryFor((JarFile)this, name);
} else {
e = new ZipEntry(name);
}
e.flag = CENFLG(cen, pos);
e.xdostime = CENTIM(cen, pos);
e.crc = CENCRC(cen, pos);
e.size = CENLEN(cen, pos);
e.csize = CENSIZ(cen, pos);
e.method = CENHOW(cen, pos);
if (CENVEM_FA(cen, pos) == FILE_ATTRIBUTES_UNIX) {
// read all bits in this field, including sym link attributes
e.extraAttributes = CENATX_PERMS(cen, pos) & 0xFFFF;
}
if (elen != 0) {
int start = pos + CENHDR + nlen;
e.setExtra0(Arrays.copyOfRange(cen, start, start + elen), true, false);
}
if (clen != 0) {
int start = pos + CENHDR + nlen + elen;
e.comment = zc.toString(cen, start, clen);
}
lastEntryName = e.name;
lastEntryPos = pos;
return e;
}
/**
* Returns the number of entries in the ZIP file.
*
* @return the number of entries in the ZIP file
* @throws IllegalStateException if the zip file has been closed
*/
public int size() {
synchronized (this) {
ensureOpen();
return res.zsrc.total;
}
}
private static class CleanableResource implements Runnable {
// The outstanding inputstreams that need to be closed
final Set istreams;
// List of cached Inflater objects for decompression
Deque inflaterCache;
final Cleanable cleanable;
Source zsrc;
CleanableResource(ZipFile zf, ZipCoder zc, File file, int mode) throws IOException {
this.cleanable = CleanerFactory.cleaner().register(zf, this);
this.istreams = Collections.newSetFromMap(new WeakHashMap<>());
this.inflaterCache = new ArrayDeque<>();
this.zsrc = Source.get(file, (mode & OPEN_DELETE) != 0, zc);
}
void clean() {
cleanable.clean();
}
/*
* Gets an inflater from the list of available inflaters or allocates
* a new one.
*/
Inflater getInflater() {
Inflater inf;
synchronized (inflaterCache) {
if ((inf = inflaterCache.poll()) != null) {
return inf;
}
}
return new Inflater(true);
}
/*
* Releases the specified inflater to the list of available inflaters.
*/
void releaseInflater(Inflater inf) {
Deque inflaters = this.inflaterCache;
if (inflaters != null) {
synchronized (inflaters) {
// double checked!
if (inflaters == this.inflaterCache) {
inf.reset();
inflaters.add(inf);
return;
}
}
}
// inflaters cache already closed - just end it.
inf.end();
}
public void run() {
IOException ioe = null;
// Release cached inflaters and close the cache first
Deque inflaters = this.inflaterCache;
if (inflaters != null) {
synchronized (inflaters) {
// no need to double-check as only one thread gets a
// chance to execute run() (Cleaner guarantee)...
Inflater inf;
while ((inf = inflaters.poll()) != null) {
inf.end();
}
// close inflaters cache
this.inflaterCache = null;
}
}
// Close streams, release their inflaters
if (istreams != null) {
synchronized (istreams) {
if (!istreams.isEmpty()) {
InputStream[] copy = istreams.toArray(new InputStream[0]);
istreams.clear();
for (InputStream is : copy) {
try {
is.close();
} catch (IOException e) {
if (ioe == null) ioe = e;
else ioe.addSuppressed(e);
}
}
}
}
}
// Release zip src
if (zsrc != null) {
synchronized (zsrc) {
try {
Source.release(zsrc);
zsrc = null;
} catch (IOException e) {
if (ioe == null) ioe = e;
else ioe.addSuppressed(e);
}
}
}
if (ioe != null) {
throw new UncheckedIOException(ioe);
}
}
}
/**
* Closes the ZIP file.
*
* Closing this ZIP file will close all of the input streams
* previously returned by invocations of the {@link #getInputStream
* getInputStream} method.
*
* @throws IOException if an I/O error has occurred
*/
public void close() throws IOException {
if (closeRequested) {
return;
}
closeRequested = true;
synchronized (this) {
// Close streams, release their inflaters, release cached inflaters
// and release zip source
try {
res.clean();
} catch (UncheckedIOException ioe) {
throw ioe.getCause();
}
}
}
private void ensureOpen() {
if (closeRequested) {
throw new IllegalStateException("zip file closed");
}
if (res.zsrc == null) {
throw new IllegalStateException("The object is not initialized.");
}
}
private void ensureOpenOrZipException() throws IOException {
if (closeRequested) {
throw new ZipException("ZipFile closed");
}
}
/*
* Inner class implementing the input stream used to read a
* (possibly compressed) zip file entry.
*/
private class ZipFileInputStream extends InputStream {
private volatile boolean closeRequested;
private long pos; // current position within entry data
private long startingPos; // Start position for the entry data
protected long rem; // number of remaining bytes within entry
protected long size; // uncompressed size of this entry
ZipFileInputStream(byte[] cen, int cenpos) {
rem = CENSIZ(cen, cenpos);
size = CENLEN(cen, cenpos);
pos = CENOFF(cen, cenpos);
// zip64
if (rem == ZIP64_MAGICVAL || size == ZIP64_MAGICVAL ||
pos == ZIP64_MAGICVAL) {
checkZIP64(cen, cenpos);
}
// negative for lazy initialization, see getDataOffset();
pos = - (pos + ZipFile.this.res.zsrc.locpos);
}
private void checkZIP64(byte[] cen, int cenpos) {
int off = cenpos + CENHDR + CENNAM(cen, cenpos);
int end = off + CENEXT(cen, cenpos);
while (off + 4 < end) {
int tag = get16(cen, off);
int sz = get16(cen, off + 2);
off += 4;
if (off + sz > end) // invalid data
break;
if (tag == EXTID_ZIP64) {
if (size == ZIP64_MAGICVAL) {
if (sz < 8 || (off + 8) > end)
break;
size = get64(cen, off);
sz -= 8;
off += 8;
}
if (rem == ZIP64_MAGICVAL) {
if (sz < 8 || (off + 8) > end)
break;
rem = get64(cen, off);
sz -= 8;
off += 8;
}
if (pos == ZIP64_MAGICVAL) {
if (sz < 8 || (off + 8) > end)
break;
pos = get64(cen, off);
sz -= 8;
off += 8;
}
break;
}
off += sz;
}
}
/*
* The Zip file spec explicitly allows the LOC extra data size to
* be different from the CEN extra data size. Since we cannot trust
* the CEN extra data size, we need to read the LOC to determine
* the entry data offset.
*/
private long initDataOffset() throws IOException {
if (pos <= 0) {
byte[] loc = new byte[LOCHDR];
pos = -pos;
int len = ZipFile.this.res.zsrc.readFullyAt(loc, 0, loc.length, pos);
if (len != LOCHDR) {
throw new ZipException("ZipFile error reading zip file");
}
if (LOCSIG(loc) != LOCSIG) {
throw new ZipException("ZipFile invalid LOC header (bad signature)");
}
pos += LOCHDR + LOCNAM(loc) + LOCEXT(loc);
startingPos = pos; // Save starting position for the entry
}
return pos;
}
public int read(byte b[], int off, int len) throws IOException {
synchronized (ZipFile.this) {
ensureOpenOrZipException();
initDataOffset();
if (rem == 0) {
return -1;
}
if (len > rem) {
len = (int) rem;
}
if (len <= 0) {
return 0;
}
len = ZipFile.this.res.zsrc.readAt(b, off, len, pos);
if (len > 0) {
pos += len;
rem -= len;
}
}
if (rem == 0) {
close();
}
return len;
}
public int read() throws IOException {
byte[] b = new byte[1];
if (read(b, 0, 1) == 1) {
return b[0] & 0xff;
} else {
return -1;
}
}
public long skip(long n) throws IOException {
synchronized (ZipFile.this) {
initDataOffset();
long newPos = pos + n;
if (n > 0) {
// If we overflowed adding the skip value or are moving
// past EOF, set the skip value to number of bytes remaining
// to reach EOF
if (newPos < 0 || n > rem) {
n = rem;
}
} else if (newPos < startingPos) {
// Tried to position before BOF so set position to the
// BOF and return the number of bytes we moved backwards
// to reach BOF
n = startingPos - pos;
}
pos += n;
rem -= n;
}
if (rem == 0) {
close();
}
return n;
}
public int available() {
return rem > Integer.MAX_VALUE ? Integer.MAX_VALUE : (int) rem;
}
public long size() {
return size;
}
public void close() {
if (closeRequested) {
return;
}
closeRequested = true;
rem = 0;
synchronized (res.istreams) {
res.istreams.remove(this);
}
}
}
/**
* Returns the names of the META-INF/MANIFEST.MF entry - if exists -
* and any signature-related files under META-INF. This method is used in
* JarFile, via SharedSecrets, as an optimization.
*/
private List getManifestAndSignatureRelatedFiles() {
synchronized (this) {
ensureOpen();
Source zsrc = res.zsrc;
int[] metanames = zsrc.signatureMetaNames;
List files = null;
if (zsrc.manifestPos >= 0) {
files = new ArrayList<>();
files.add(getEntryName(zsrc.manifestPos));
}
if (metanames != null) {
if (files == null) {
files = new ArrayList<>();
}
for (int i = 0; i < metanames.length; i++) {
files.add(getEntryName(metanames[i]));
}
}
return files == null ? List.of() : files;
}
}
/**
* Returns the number of the META-INF/MANIFEST.MF entries, case insensitive.
* When this number is greater than 1, JarVerifier will treat a file as
* unsigned.
*/
private int getManifestNum() {
synchronized (this) {
ensureOpen();
return res.zsrc.manifestNum;
}
}
/**
* Returns the name of the META-INF/MANIFEST.MF entry, ignoring
* case. If {@code onlyIfSignatureRelatedFiles} is true, we only return the
* manifest if there is also at least one signature-related file.
* This method is used in JarFile, via SharedSecrets, as an optimization
* when looking up the manifest file.
*/
private String getManifestName(boolean onlyIfSignatureRelatedFiles) {
synchronized (this) {
ensureOpen();
Source zsrc = res.zsrc;
int pos = zsrc.manifestPos;
if (pos >= 0 && (!onlyIfSignatureRelatedFiles || zsrc.signatureMetaNames != null)) {
return getEntryName(pos);
}
}
return null;
}
/**
* Returns the versions for which there exists a non-directory
* entry that begin with "META-INF/versions/" (case ignored).
* This method is used in JarFile, via SharedSecrets, as an
* optimization when looking up potentially versioned entries.
* Returns an empty array if no versioned entries exist.
*/
private int[] getMetaInfVersions() {
synchronized (this) {
ensureOpen();
return res.zsrc.metaVersions;
}
}
private static boolean isWindows;
static {
SharedSecrets.setJavaUtilZipFileAccess(
new JavaUtilZipFileAccess() {
@Override
public boolean startsWithLocHeader(ZipFile zip) {
return zip.res.zsrc.startsWithLoc;
}
@Override
public List getManifestAndSignatureRelatedFiles(JarFile jar) {
return ((ZipFile)jar).getManifestAndSignatureRelatedFiles();
}
@Override
public int getManifestNum(JarFile jar) {
return ((ZipFile)jar).getManifestNum();
}
@Override
public String getManifestName(JarFile jar, boolean onlyIfHasSignatureRelatedFiles) {
return ((ZipFile)jar).getManifestName(onlyIfHasSignatureRelatedFiles);
}
@Override
public int[] getMetaInfVersions(JarFile jar) {
return ((ZipFile)jar).getMetaInfVersions();
}
@Override
public Enumeration entries(ZipFile zip) {
return zip.jarEntries();
}
@Override
public Stream stream(ZipFile zip) {
return zip.jarStream();
}
@Override
public Stream entryNameStream(ZipFile zip) {
return zip.entryNameStream();
}
@Override
public int getExtraAttributes(ZipEntry ze) {
return ze.extraAttributes;
}
@Override
public void setExtraAttributes(ZipEntry ze, int extraAttrs) {
ze.extraAttributes = extraAttrs;
}
}
);
isWindows = VM.getSavedProperty("os.name").contains("Windows");
}
private static class Source {
// While this is only used from ZipFile, defining it there would cause
// a bootstrap cycle that would leave this initialized as null
private static final JavaUtilJarAccess JUJA = SharedSecrets.javaUtilJarAccess();
// "META-INF/".length()
private static final int META_INF_LEN = 9;
private static final int[] EMPTY_META_VERSIONS = new int[0];
private final Key key; // the key in files
private final @Stable ZipCoder zc; // zip coder used to decode/encode
private int refs = 1;
private RandomAccessFile zfile; // zfile of the underlying zip file
private byte[] cen; // CEN & ENDHDR
private long locpos; // position of first LOC header (usually 0)
private byte[] comment; // zip file comment
// list of meta entries in META-INF dir
private int manifestPos = -1; // position of the META-INF/MANIFEST.MF, if exists
private int manifestNum = 0; // number of META-INF/MANIFEST.MF, case insensitive
private int[] signatureMetaNames; // positions of signature related entries, if such exist
private int[] metaVersions; // list of unique versions found in META-INF/versions/
private final boolean startsWithLoc; // true, if zip file starts with LOCSIG (usually true)
// A Hashmap for all entries.
//
// A cen entry of Zip/JAR file. As we have one for every entry in every active Zip/JAR,
// We might have a lot of these in a typical system. In order to save space we don't
// keep the name in memory, but merely remember a 32 bit {@code hash} value of the
// entry name and its offset {@code pos} in the central directory hdeader.
//
// private static class Entry {
// int hash; // 32 bit hashcode on name
// int next; // hash chain: index into entries
// int pos; // Offset of central directory file header
// }
// private Entry[] entries; // array of hashed cen entry
//
// To reduce the total size of entries further, we use a int[] here to store 3 "int"
// {@code hash}, {@code next} and {@code pos} for each entry. The entry can then be
// referred by their index of their positions in the {@code entries}.
//
private int[] entries; // array of hashed cen entry
// Checks the entry at offset pos in the CEN, calculates the Entry values as per above,
// then returns the length of the entry name.
private int checkAndAddEntry(int pos, int index)
throws ZipException
{
byte[] cen = this.cen;
if (CENSIG(cen, pos) != CENSIG) {
zerror("invalid CEN header (bad signature)");
}
int method = CENHOW(cen, pos);
int flag = CENFLG(cen, pos);
if ((flag & 1) != 0) {
zerror("invalid CEN header (encrypted entry)");
}
if (method != STORED && method != DEFLATED) {
zerror("invalid CEN header (bad compression method: " + method + ")");
}
int entryPos = pos + CENHDR;
int nlen = CENNAM(cen, pos);
if (entryPos + nlen > cen.length - ENDHDR) {
zerror("invalid CEN header (bad header size)");
}
try {
ZipCoder zcp = zipCoderForPos(pos);
int hash = zcp.checkedHash(cen, entryPos, nlen);
int hsh = (hash & 0x7fffffff) % tablelen;
int next = table[hsh];
table[hsh] = index;
// Record the CEN offset and the name hash in our hash cell.
entries[index++] = hash;
entries[index++] = next;
entries[index ] = pos;
} catch (Exception e) {
zerror("invalid CEN header (bad entry name)");
}
return nlen;
}
private int getEntryHash(int index) { return entries[index]; }
private int getEntryNext(int index) { return entries[index + 1]; }
private int getEntryPos(int index) { return entries[index + 2]; }
private static final int ZIP_ENDCHAIN = -1;
private int total; // total number of entries
private int[] table; // Hash chain heads: indexes into entries
private int tablelen; // number of hash heads
private static class Key {
final BasicFileAttributes attrs;
File file;
final boolean utf8;
public Key(File file, BasicFileAttributes attrs, ZipCoder zc) {
this.attrs = attrs;
this.file = file;
this.utf8 = zc.isUTF8();
}
public int hashCode() {
long t = utf8 ? 0 : Long.MAX_VALUE;
t += attrs.lastModifiedTime().toMillis();
return ((int)(t ^ (t >>> 32))) + file.hashCode();
}
public boolean equals(Object obj) {
if (obj instanceof Key key) {
if (key.utf8 != utf8) {
return false;
}
if (!attrs.lastModifiedTime().equals(key.attrs.lastModifiedTime())) {
return false;
}
Object fk = attrs.fileKey();
if (fk != null) {
return fk.equals(key.attrs.fileKey());
} else {
return file.equals(key.file);
}
}
return false;
}
}
private static final HashMap files = new HashMap<>();
static Source get(File file, boolean toDelete, ZipCoder zc) throws IOException {
final Key key;
try {
key = new Key(file,
Files.readAttributes(file.toPath(), BasicFileAttributes.class),
zc);
} catch (InvalidPathException ipe) {
throw new IOException(ipe);
}
Source src;
synchronized (files) {
src = files.get(key);
if (src != null) {
src.refs++;
return src;
}
}
src = new Source(key, toDelete, zc);
synchronized (files) {
if (files.containsKey(key)) { // someone else put in first
src.close(); // close the newly created one
src = files.get(key);
src.refs++;
return src;
}
files.put(key, src);
return src;
}
}
static void release(Source src) throws IOException {
synchronized (files) {
if (src != null && --src.refs == 0) {
files.remove(src.key);
src.close();
}
}
}
private Source(Key key, boolean toDelete, ZipCoder zc) throws IOException {
this.zc = zc;
this.key = key;
if (toDelete) {
if (isWindows) {
this.zfile = SharedSecrets.getJavaIORandomAccessFileAccess()
.openAndDelete(key.file, "r");
} else {
this.zfile = new RandomAccessFile(key.file, "r");
key.file.delete();
}
} else {
this.zfile = new RandomAccessFile(key.file, "r");
}
try {
initCEN(-1);
byte[] buf = new byte[4];
readFullyAt(buf, 0, 4, 0);
this.startsWithLoc = (LOCSIG(buf) == LOCSIG);
} catch (IOException x) {
try {
this.zfile.close();
} catch (IOException xx) {}
throw x;
}
}
private void close() throws IOException {
zfile.close();
zfile = null;
cen = null;
entries = null;
table = null;
manifestPos = -1;
manifestNum = 0;
signatureMetaNames = null;
metaVersions = EMPTY_META_VERSIONS;
}
private static final int BUF_SIZE = 8192;
private final int readFullyAt(byte[] buf, int off, int len, long pos)
throws IOException
{
synchronized (zfile) {
zfile.seek(pos);
int N = len;
while (N > 0) {
int n = Math.min(BUF_SIZE, N);
zfile.readFully(buf, off, n);
off += n;
N -= n;
}
return len;
}
}
private final int readAt(byte[] buf, int off, int len, long pos)
throws IOException
{
synchronized (zfile) {
zfile.seek(pos);
return zfile.read(buf, off, len);
}
}
private static class End {
int centot; // 4 bytes
long cenlen; // 4 bytes
long cenoff; // 4 bytes
long endpos; // 4 bytes
}
/*
* Searches for end of central directory (END) header. The contents of
* the END header will be read and placed in endbuf. Returns the file
* position of the END header, otherwise returns -1 if the END header
* was not found or an error occurred.
*/
private End findEND() throws IOException {
long ziplen = zfile.length();
if (ziplen <= 0)
zerror("zip file is empty");
End end = new End();
byte[] buf = new byte[READBLOCKSZ];
long minHDR = (ziplen - END_MAXLEN) > 0 ? ziplen - END_MAXLEN : 0;
long minPos = minHDR - (buf.length - ENDHDR);
for (long pos = ziplen - buf.length; pos >= minPos; pos -= (buf.length - ENDHDR)) {
int off = 0;
if (pos < 0) {
// Pretend there are some NUL bytes before start of file
off = (int)-pos;
Arrays.fill(buf, 0, off, (byte)0);
}
int len = buf.length - off;
if (readFullyAt(buf, off, len, pos + off) != len ) {
zerror("zip END header not found");
}
// Now scan the block backwards for END header signature
for (int i = buf.length - ENDHDR; i >= 0; i--) {
if (buf[i+0] == (byte)'P' &&
buf[i+1] == (byte)'K' &&
buf[i+2] == (byte)'\005' &&
buf[i+3] == (byte)'\006') {
// Found ENDSIG header
byte[] endbuf = Arrays.copyOfRange(buf, i, i + ENDHDR);
end.centot = ENDTOT(endbuf);
end.cenlen = ENDSIZ(endbuf);
end.cenoff = ENDOFF(endbuf);
end.endpos = pos + i;
int comlen = ENDCOM(endbuf);
if (end.endpos + ENDHDR + comlen != ziplen) {
// ENDSIG matched, however the size of file comment in it does
// not match the real size. One "common" cause for this problem
// is some "extra" bytes are padded at the end of the zipfile.
// Let's do some extra verification, we don't care about the
// performance in this situation.
byte[] sbuf = new byte[4];
long cenpos = end.endpos - end.cenlen;
long locpos = cenpos - end.cenoff;
if (cenpos < 0 ||
locpos < 0 ||
readFullyAt(sbuf, 0, sbuf.length, cenpos) != 4 ||
GETSIG(sbuf) != CENSIG ||
readFullyAt(sbuf, 0, sbuf.length, locpos) != 4 ||
GETSIG(sbuf) != LOCSIG) {
continue;
}
}
if (comlen > 0) { // this zip file has comlen
comment = new byte[comlen];
if (readFullyAt(comment, 0, comlen, end.endpos + ENDHDR) != comlen) {
zerror("zip comment read failed");
}
}
// must check for a zip64 end record; it is always permitted to be present
try {
byte[] loc64 = new byte[ZIP64_LOCHDR];
if (end.endpos < ZIP64_LOCHDR ||
readFullyAt(loc64, 0, loc64.length, end.endpos - ZIP64_LOCHDR)
!= loc64.length || GETSIG(loc64) != ZIP64_LOCSIG) {
return end;
}
long end64pos = ZIP64_LOCOFF(loc64);
byte[] end64buf = new byte[ZIP64_ENDHDR];
if (readFullyAt(end64buf, 0, end64buf.length, end64pos)
!= end64buf.length || GETSIG(end64buf) != ZIP64_ENDSIG) {
return end;
}
// end64 candidate found,
long cenlen64 = ZIP64_ENDSIZ(end64buf);
long cenoff64 = ZIP64_ENDOFF(end64buf);
long centot64 = ZIP64_ENDTOT(end64buf);
// double-check
if (cenlen64 != end.cenlen && end.cenlen != ZIP64_MAGICVAL ||
cenoff64 != end.cenoff && end.cenoff != ZIP64_MAGICVAL ||
centot64 != end.centot && end.centot != ZIP64_MAGICCOUNT) {
return end;
}
// to use the end64 values
end.cenlen = cenlen64;
end.cenoff = cenoff64;
end.centot = (int)centot64; // assume total < 2g
end.endpos = end64pos;
} catch (IOException x) {} // no zip64 loc/end
return end;
}
}
}
throw new ZipException("zip END header not found");
}
// Reads zip file central directory.
private void initCEN(int knownTotal) throws IOException {
// Prefer locals for better performance during startup
byte[] cen;
if (knownTotal == -1) {
End end = findEND();
if (end.endpos == 0) {
locpos = 0;
total = 0;
entries = new int[0];
this.cen = null;
return; // only END header present
}
if (end.cenlen > end.endpos)
zerror("invalid END header (bad central directory size)");
long cenpos = end.endpos - end.cenlen; // position of CEN table
// Get position of first local file (LOC) header, taking into
// account that there may be a stub prefixed to the zip file.
locpos = cenpos - end.cenoff;
if (locpos < 0) {
zerror("invalid END header (bad central directory offset)");
}
// read in the CEN and END
cen = this.cen = new byte[(int)(end.cenlen + ENDHDR)];
if (readFullyAt(cen, 0, cen.length, cenpos) != end.cenlen + ENDHDR) {
zerror("read CEN tables failed");
}
this.total = end.centot;
} else {
cen = this.cen;
this.total = knownTotal;
}
// hash table for entries
int entriesLength = this.total * 3;
entries = new int[entriesLength];
int tablelen = ((total/2) | 1); // Odd -> fewer collisions
this.tablelen = tablelen;
int[] table = new int[tablelen];
this.table = table;
Arrays.fill(table, ZIP_ENDCHAIN);
// list for all meta entries
ArrayList signatureNames = null;
// Set of all version numbers seen in META-INF/versions/
Set metaVersionsSet = null;
// Iterate through the entries in the central directory
int idx = 0; // Index into the entries array
int pos = 0;
int entryPos = CENHDR;
int limit = cen.length - ENDHDR;
manifestNum = 0;
while (entryPos <= limit) {
if (idx >= entriesLength) {
// This will only happen if the zip file has an incorrect
// ENDTOT field, which usually means it contains more than
// 65535 entries.
initCEN(countCENHeaders(cen, limit));
return;
}
// Checks the entry and adds values to entries[idx ... idx+2]
int nlen = checkAndAddEntry(pos, idx);
idx += 3;
// Adds name to metanames.
if (isMetaName(cen, entryPos, nlen)) {
// nlen is at least META_INF_LENGTH
if (isManifestName(entryPos + META_INF_LEN, nlen - META_INF_LEN)) {
manifestPos = pos;
manifestNum++;
} else {
if (isSignatureRelated(entryPos, nlen)) {
if (signatureNames == null)
signatureNames = new ArrayList<>(4);
signatureNames.add(pos);
}
// If this is a versioned entry, parse the version
// and store it for later. This optimizes lookup
// performance in multi-release jar files
int version = getMetaVersion(entryPos + META_INF_LEN, nlen - META_INF_LEN);
if (version > 0) {
if (metaVersionsSet == null)
metaVersionsSet = new TreeSet<>();
metaVersionsSet.add(version);
}
}
}
// skip to the start of the next entry
pos = nextEntryPos(pos, entryPos, nlen);
entryPos = pos + CENHDR;
}
// Adjust the total entries
this.total = idx / 3;
if (signatureNames != null) {
int len = signatureNames.size();
signatureMetaNames = new int[len];
for (int j = 0; j < len; j++) {
signatureMetaNames[j] = signatureNames.get(j);
}
}
if (metaVersionsSet != null) {
metaVersions = new int[metaVersionsSet.size()];
int c = 0;
for (Integer version : metaVersionsSet) {
metaVersions[c++] = version;
}
} else {
metaVersions = EMPTY_META_VERSIONS;
}
if (pos + ENDHDR != cen.length) {
zerror("invalid CEN header (bad header size)");
}
}
private int nextEntryPos(int pos, int entryPos, int nlen) {
return entryPos + nlen + CENCOM(cen, pos) + CENEXT(cen, pos);
}
private static void zerror(String msg) throws ZipException {
throw new ZipException(msg);
}
/*
* Returns the {@code pos} of the zip cen entry corresponding to the
* specified entry name, or -1 if not found.
*/
private int getEntryPos(String name, boolean addSlash) {
if (total == 0) {
return -1;
}
int hsh = ZipCoder.hash(name);
int idx = table[(hsh & 0x7fffffff) % tablelen];
// Search down the target hash chain for a entry whose
// 32 bit hash matches the hashed name.
while (idx != ZIP_ENDCHAIN) {
if (getEntryHash(idx) == hsh) {
// The CEN name must match the specfied one
int pos = getEntryPos(idx);
try {
ZipCoder zc = zipCoderForPos(pos);
String entry = zc.toString(cen, pos + CENHDR, CENNAM(cen, pos));
// If addSlash is true we'll test for name+/ in addition to
// name, unless name is the empty string or already ends with a
// slash
int entryLen = entry.length();
int nameLen = name.length();
if ((entryLen == nameLen && entry.equals(name)) ||
(addSlash &&
nameLen + 1 == entryLen &&
entry.startsWith(name) &&
entry.charAt(entryLen - 1) == '/')) {
return pos;
}
} catch (IllegalArgumentException iae) {
// Ignore
}
}
idx = getEntryNext(idx);
}
return -1;
}
private ZipCoder zipCoderForPos(int pos) {
if (zc.isUTF8()) {
return zc;
}
if ((CENFLG(cen, pos) & USE_UTF8) != 0) {
return ZipCoder.UTF8;
}
return zc;
}
/**
* Returns true if the bytes represent a non-directory name
* beginning with "META-INF/", disregarding ASCII case.
*/
private static boolean isMetaName(byte[] name, int off, int len) {
// Use the "oldest ASCII trick in the book":
// ch | 0x20 == Character.toLowerCase(ch)
return len > META_INF_LEN // "META-INF/".length()
&& name[off + len - 1] != '/' // non-directory
&& (name[off++] | 0x20) == 'm'
&& (name[off++] | 0x20) == 'e'
&& (name[off++] | 0x20) == 't'
&& (name[off++] | 0x20) == 'a'
&& (name[off++] ) == '-'
&& (name[off++] | 0x20) == 'i'
&& (name[off++] | 0x20) == 'n'
&& (name[off++] | 0x20) == 'f'
&& (name[off] ) == '/';
}
/*
* Check if the bytes represents a name equals to MANIFEST.MF
*/
private boolean isManifestName(int off, int len) {
byte[] name = cen;
return (len == 11 // "MANIFEST.MF".length()
&& (name[off++] | 0x20) == 'm'
&& (name[off++] | 0x20) == 'a'
&& (name[off++] | 0x20) == 'n'
&& (name[off++] | 0x20) == 'i'
&& (name[off++] | 0x20) == 'f'
&& (name[off++] | 0x20) == 'e'
&& (name[off++] | 0x20) == 's'
&& (name[off++] | 0x20) == 't'
&& (name[off++] ) == '.'
&& (name[off++] | 0x20) == 'm'
&& (name[off] | 0x20) == 'f');
}
private boolean isSignatureRelated(int off, int len) {
// Only called when isMetaName(name, off, len) is true, which means
// len is at least META_INF_LENGTH
// assert isMetaName(name, off, len)
boolean signatureRelated = false;
byte[] name = cen;
if (name[off + len - 3] == '.') {
// Check if entry ends with .EC and .SF
int b1 = name[off + len - 2] | 0x20;
int b2 = name[off + len - 1] | 0x20;
if ((b1 == 'e' && b2 == 'c') || (b1 == 's' && b2 == 'f')) {
signatureRelated = true;
}
} else if (name[off + len - 4] == '.') {
// Check if entry ends with .DSA and .RSA
int b1 = name[off + len - 3] | 0x20;
int b2 = name[off + len - 2] | 0x20;
int b3 = name[off + len - 1] | 0x20;
if ((b1 == 'r' || b1 == 'd') && b2 == 's' && b3 == 'a') {
signatureRelated = true;
}
}
// Above logic must match SignatureFileVerifier.isBlockOrSF
assert(signatureRelated == SignatureFileVerifier
.isBlockOrSF(new String(name, off, len, UTF_8.INSTANCE)
.toUpperCase(Locale.ENGLISH)));
return signatureRelated;
}
/*
* If the bytes represents a non-directory name beginning
* with "versions/", continuing with a positive integer,
* followed by a '/', then return that integer value.
* Otherwise, return 0
*/
private int getMetaVersion(int off, int len) {
byte[] name = cen;
int nend = off + len;
if (!(len > 10 // "versions//".length()
&& name[off + len - 1] != '/' // non-directory
&& (name[off++] | 0x20) == 'v'
&& (name[off++] | 0x20) == 'e'
&& (name[off++] | 0x20) == 'r'
&& (name[off++] | 0x20) == 's'
&& (name[off++] | 0x20) == 'i'
&& (name[off++] | 0x20) == 'o'
&& (name[off++] | 0x20) == 'n'
&& (name[off++] | 0x20) == 's'
&& (name[off++] ) == '/')) {
return 0;
}
int version = 0;
while (off < nend) {
final byte c = name[off++];
if (c == '/') {
return version;
}
if (c < '0' || c > '9') {
return 0;
}
version = version * 10 + c - '0';
// Check for overflow and leading zeros
if (version <= 0) {
return 0;
}
}
return 0;
}
/**
* Returns the number of CEN headers in a central directory.
* Will not throw, even if the zip file is corrupt.
*
* @param cen copy of the bytes in a zip file's central directory
* @param size number of bytes in central directory
*/
private static int countCENHeaders(byte[] cen, int size) {
int count = 0;
for (int p = 0;
p + CENHDR <= size;
p += CENHDR + CENNAM(cen, p) + CENEXT(cen, p) + CENCOM(cen, p))
count++;
return count;
}
}
}