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	/*
	* Copyright (c) 1997, 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.jar;

	import java.util.zip.*;
	import java.io.*;
	import sun.security.util.ManifestEntryVerifier;
	import jdk.internal.util.jar.JarIndex;

	/**
	* The {@code JarInputStream} class is used to read the contents of
	* a JAR file from any input stream. It extends the class
	* {@code java.util.zip.ZipInputStream} with support for reading
	* an optional {@code Manifest} entry. The {@code Manifest}
	* can be used to store meta-information about the JAR file and its entries.
	*
	* @author David Connelly
	* @see Manifest
	* @see java.util.zip.ZipInputStream
	* @since 1.2
	*/
	public class JarInputStream extends ZipInputStream {
	private Manifest man;
	private JarEntry first;
	private JarVerifier jv;
	private ManifestEntryVerifier mev;
	private final boolean doVerify;
	private boolean tryManifest;

	/**
	* Creates a new {@code JarInputStream} and reads the optional
	* manifest. If a manifest is present, also attempts to verify
	* the signatures if the JarInputStream is signed.
	* @param in the actual input stream
	* @throws IOException if an I/O error has occurred
	*/
	public JarInputStream(InputStream in) throws IOException {
	this(in, true);
	}

	/**
	* Creates a new {@code JarInputStream} and reads the optional
	* manifest. If a manifest is present and verify is true, also attempts
	* to verify the signatures if the JarInputStream is signed.
	*
	* @param in the actual input stream
	* @param verify whether or not to verify the JarInputStream if
	* it is signed.
	* @throws IOException if an I/O error has occurred
	*/
	public JarInputStream(InputStream in, boolean verify) throws IOException {
	super(in);
	this.doVerify = verify;

	// This implementation assumes the META-INF/MANIFEST.MF entry
	// should be either the first or the second entry (when preceded
	// by the dir META-INF/). It skips the META-INF/ and then
	// "consumes" the MANIFEST.MF to initialize the Manifest object.
	JarEntry e = (JarEntry)super.getNextEntry();
	if (e != null && e.getName().equalsIgnoreCase("META-INF/"))
	e = (JarEntry)super.getNextEntry();
	first = checkManifest(e);
	}

	private JarEntry checkManifest(JarEntry e)
	throws IOException
	{
	if (e != null && JarFile.MANIFEST_NAME.equalsIgnoreCase(e.getName())) {
	man = new Manifest();
	byte[] bytes = readAllBytes();
	man.read(new ByteArrayInputStream(bytes));
	closeEntry();
	if (doVerify) {
	jv = new JarVerifier(e.getName(), bytes);
	mev = new ManifestEntryVerifier(man);
	}
	return (JarEntry)super.getNextEntry();
	}
	return e;
	}

	/**
	* Returns the {@code Manifest} for this JAR file, or
	* {@code null} if none.
	*
	* @return the {@code Manifest} for this JAR file, or
	* {@code null} if none.
	*/
	public Manifest getManifest() {
	return man;
	}

	/**
	* Reads the next ZIP file entry and positions the stream at the
	* beginning of the entry data. If verification has been enabled,
	* any invalid signature detected while positioning the stream for
	* the next entry will result in an exception.
	* @throws ZipException if a ZIP file error has occurred
	* @throws IOException if an I/O error has occurred
	* @throws SecurityException if any of the jar file entries
	* are incorrectly signed.
	*/
	public ZipEntry getNextEntry() throws IOException {
	JarEntry e;
	if (first == null) {
	e = (JarEntry)super.getNextEntry();
	if (tryManifest) {
	e = checkManifest(e);
	tryManifest = false;
	}
	} else {
	e = first;
	if (first.getName().equalsIgnoreCase(JarIndex.INDEX_NAME))
	tryManifest = true;
	first = null;
	}
	if (jv != null && e != null) {
	// At this point, we might have parsed all the meta-inf
	// entries and have nothing to verify. If we have
	// nothing to verify, get rid of the JarVerifier object.
	if (jv.nothingToVerify() == true) {
	jv = null;
	mev = null;
	} else {
	jv.beginEntry(e, mev);
	}
	}
	return e;
	}

	/**
	* Reads the next JAR file entry and positions the stream at the
	* beginning of the entry data. If verification has been enabled,
	* any invalid signature detected while positioning the stream for
	* the next entry will result in an exception.
	* @return the next JAR file entry, or null if there are no more entries
	* @throws ZipException if a ZIP file error has occurred
	* @throws IOException if an I/O error has occurred
	* @throws SecurityException if any of the jar file entries
	* are incorrectly signed.
	*/
	public JarEntry getNextJarEntry() throws IOException {
	return (JarEntry)getNextEntry();
	}

	/**
	* Reads from the current JAR file entry into an array of bytes.
	* If {@code len} is not zero, the method
	* blocks until some input is available; otherwise, no
	* bytes are read and {@code 0} is returned.
	* If verification has been enabled, any invalid signature
	* on the current entry will be reported at some point before the
	* end of the entry is reached.
	* @param b the buffer into which the data is read
	* @param off the start offset in the destination array {@code b}
	* @param len the maximum number of bytes to read
	* @return the actual number of bytes read, or -1 if the end of the
	* entry is reached
	* @throws NullPointerException If {@code b} is {@code null}.
	* @throws IndexOutOfBoundsException If {@code off} is negative,
	* {@code len} is negative, or {@code len} is greater than
	* {@code b.length - off}
	* @throws ZipException if a ZIP file error has occurred
	* @throws IOException if an I/O error has occurred
	* @throws SecurityException if any of the jar file entries
	* are incorrectly signed.
	*/
	public int read(byte[] b, int off, int len) throws IOException {
	int n;
	if (first == null) {
	n = super.read(b, off, len);
	} else {
	n = -1;
	}
	if (jv != null) {
	jv.update(n, b, off, len, mev);
	}
	return n;
	}

	/**
	* Creates a new {@code JarEntry} ({@code ZipEntry}) for the
	* specified JAR file entry name. The manifest attributes of
	* the specified JAR file entry name will be copied to the new
	* <CODE>JarEntry</CODE>.
	*
	* @param name the name of the JAR/ZIP file entry
	* @return the {@code JarEntry} object just created
	*/
	protected ZipEntry createZipEntry(String name) {
	JarEntry e = new JarEntry(name);
	if (man != null) {
	e.attr = man.getAttributes(name);
	}
	return e;
	}
	}

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