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8304013: Add a fast, non-manual alternative to test/jdk/java/util/zip…
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…/ZipFile/TestTooManyEntries

Reviewed-by: lancea, martin
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eirbjo authored and Lance Andersen committed Mar 26, 2023
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238 changes: 238 additions & 0 deletions test/jdk/java/util/zip/ZipFile/EndOfCenValidation.java
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/*
* Copyright (c) 2023, 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.
*
* 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.
*/

/* @test
* @bug 8272746
* @summary Verify that ZipFile rejects files with CEN sizes exceeding the implementation limit
* @run testng/othervm EndOfCenValidation
*/

import org.testng.annotations.AfterTest;
import org.testng.annotations.BeforeTest;
import org.testng.annotations.Test;

import java.io.*;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.channels.FileChannel;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.StandardOpenOption;
import java.util.Arrays;
import java.util.EnumSet;
import java.util.zip.ZipEntry;
import java.util.zip.ZipException;
import java.util.zip.ZipFile;
import java.util.zip.ZipOutputStream;

import static org.testng.Assert.*;

/**
* This test augments {@link TestTooManyEntries}. It creates sparse ZIPs where
* the CEN size is inflated to the desired value. This helps this test run
* fast with much less resources.
*
* While the CEN in these files are zero-filled and the produced ZIPs are technically
* invalid, the CEN is never actually read by ZipFile since it does
* 'End of central directory record' (END header) validation before reading the CEN.
*/
public class EndOfCenValidation {

// Zip files produced by this test
public static final Path CEN_TOO_LARGE_ZIP = Path.of("cen-size-too-large.zip");
public static final Path INVALID_CEN_SIZE = Path.of("invalid-zen-size.zip");
public static final Path BAD_CEN_OFFSET_ZIP = Path.of("bad-cen-offset.zip");
// Some ZipFile constants for manipulating the 'End of central directory record' (END header)
private static final int ENDHDR = ZipFile.ENDHDR; // End of central directory record size
private static final int ENDSIZ = ZipFile.ENDSIZ; // Offset of CEN size field within ENDHDR
private static final int ENDOFF = ZipFile.ENDOFF; // Offset of CEN offset field within ENDHDR
// Maximum allowed CEN size allowed by ZipFile
private static int MAX_CEN_SIZE = Integer.MAX_VALUE - ENDHDR - 1;

// Expected message when CEN size does not match file size
private static final String INVALID_CEN_BAD_SIZE = "invalid END header (bad central directory size)";
// Expected message when CEN offset is too large
private static final String INVALID_CEN_BAD_OFFSET = "invalid END header (bad central directory offset)";
// Expected message when CEN size is too large
private static final String INVALID_CEN_SIZE_TOO_LARGE = "invalid END header (central directory size too large)";

// A valid ZIP file, used as a template
private byte[] zipBytes;

/**
* Create a valid ZIP file, used as a template
* @throws IOException if an error occurs
*/
@BeforeTest
public void setup() throws IOException {
zipBytes = templateZip();
}

/**
* Delete big files after test, in case the file system did not support sparse files.
* @throws IOException if an error occurs
*/
@AfterTest
public void cleanup() throws IOException {
Files.deleteIfExists(CEN_TOO_LARGE_ZIP);
Files.deleteIfExists(INVALID_CEN_SIZE);
Files.deleteIfExists(BAD_CEN_OFFSET_ZIP);
}

/**
* Validates that an 'End of central directory record' (END header) with a CEN
* length exceeding {@link #MAX_CEN_SIZE} limit is rejected
* @throws IOException if an error occurs
*/
@Test
public void shouldRejectTooLargeCenSize() throws IOException {
int size = MAX_CEN_SIZE + 1;

Path zip = zipWithModifiedEndRecord(size, true, 0, CEN_TOO_LARGE_ZIP);

ZipException ex = expectThrows(ZipException.class, () -> {
new ZipFile(zip.toFile());
});

assertEquals(ex.getMessage(), INVALID_CEN_SIZE_TOO_LARGE);
}

/**
* Validate that an 'End of central directory record' (END header)
* where the value of the CEN size field exceeds the position of
* the END header is rejected.
* @throws IOException if an error occurs
*/
@Test
public void shouldRejectInvalidCenSize() throws IOException {

int size = MAX_CEN_SIZE;

Path zip = zipWithModifiedEndRecord(size, false, 0, INVALID_CEN_SIZE);

ZipException ex = expectThrows(ZipException.class, () -> {
new ZipFile(zip.toFile());
});

assertEquals(ex.getMessage(), INVALID_CEN_BAD_SIZE);
}

/**
* Validate that an 'End of central directory record' (the END header)
* where the value of the CEN offset field is larger than the position
* of the END header minus the CEN size is rejected
* @throws IOException if an error occurs
*/
@Test
public void shouldRejectInvalidCenOffset() throws IOException {

int size = MAX_CEN_SIZE;

Path zip = zipWithModifiedEndRecord(size, true, 100, BAD_CEN_OFFSET_ZIP);

ZipException ex = expectThrows(ZipException.class, () -> {
new ZipFile(zip.toFile());
});

assertEquals(ex.getMessage(), INVALID_CEN_BAD_OFFSET);
}

/**
* Create an ZIP file with a single entry, then modify the CEN size
* in the 'End of central directory record' (END header) to the given size.
*
* The CEN is optionally "inflated" with trailing zero bytes such that
* its actual size matches the one stated in the END header.
*
* The CEN offset is optiontially adjusted by the given amount
*
* The resulting ZIP is technically not valid, but it does allow us
* to test that large or invalid CEN sizes are rejected
* @param cenSize the CEN size to put in the END record
* @param inflateCen if true, zero-pad the CEN to the desired size
* @param cenOffAdjust Adjust the CEN offset field of the END record with this amount
* @throws IOException if an error occurs
*/
private Path zipWithModifiedEndRecord(int cenSize,
boolean inflateCen,
int cenOffAdjust,
Path zip) throws IOException {

// A byte buffer for reading the END
ByteBuffer buffer = ByteBuffer.wrap(zipBytes.clone()).order(ByteOrder.LITTLE_ENDIAN);

// Offset of the END header
int endOffset = buffer.limit() - ENDHDR;

// Modify the CEN size
int sizeOffset = endOffset + ENDSIZ;
int currentCenSize = buffer.getInt(sizeOffset);
buffer.putInt(sizeOffset, cenSize);

// Optionally modify the CEN offset
if (cenOffAdjust != 0) {
int offOffset = endOffset + ENDOFF;
int currentCenOff = buffer.getInt(offOffset);
buffer.putInt(offOffset, currentCenOff + cenOffAdjust);
}

// When creating a sparse file, the file must not already exit
Files.deleteIfExists(zip);

// Open a FileChannel for writing a sparse file
EnumSet<StandardOpenOption> options = EnumSet.of(StandardOpenOption.CREATE_NEW,
StandardOpenOption.WRITE,
StandardOpenOption.SPARSE);

try (FileChannel channel = FileChannel.open(zip, options)) {

// Write everything up to END
channel.write(buffer.slice(0, buffer.limit() - ENDHDR));

if (inflateCen) {
// Inject "empty bytes" to make the actual CEN size match the END
int injectBytes = cenSize - currentCenSize;
channel.position(channel.position() + injectBytes);
}
// Write the modified END
channel.write(buffer.slice(buffer.limit() - ENDHDR, ENDHDR));
}
return zip;
}

/**
* Produce a byte array of a ZIP with a single entry
*
* @throws IOException if an error occurs
*/
private byte[] templateZip() throws IOException {
ByteArrayOutputStream bout = new ByteArrayOutputStream();
try (ZipOutputStream zo = new ZipOutputStream(bout)) {
ZipEntry entry = new ZipEntry("duke.txt");
zo.putNextEntry(entry);
zo.write("duke".getBytes(StandardCharsets.UTF_8));
}
return bout.toByteArray();
}
}

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