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eirbjojaikiran
eirbjo
and
jaikiran
committedNov 14, 2023
8303920: Avoid calling out to python in DataDescriptorSignatureMissing test
Co-authored-by: Jaikiran Pai <jpai@openjdk.org> Reviewed-by: jpai, lancea, iris
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‎test/jdk/java/util/zip/DataDescriptorSignatureMissing.java

+120-106
Original file line numberDiff line numberDiff line change
@@ -1,5 +1,6 @@
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/*
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* Copyright 2012 Google, Inc. All Rights Reserved.
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* Copyright (c) 2023, Oracle and/or its affiliates. All rights reserved.
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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*
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* This code is free software; you can redistribute it and/or modify it
@@ -24,124 +25,137 @@
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/**
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* @test
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* @bug 8056934
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* @summary Check ability to read zip files created by python zipfile
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* implementation, which fails to write optional (but recommended) data
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* descriptor signatures. Repro scenario is a Java -> Python -> Java round trip:
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* - ZipOutputStream creates zip file with DEFLATED entries and data
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* descriptors with optional signature "PK0x0708".
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* - Python reads those entries, preserving the 0x08 flag byte
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* - Python outputs those entries with data descriptors lacking the
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* optional signature.
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* - ZipInputStream cannot handle the missing signature
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*
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* @summary Verify the ability to read zip files whose local header
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* data descriptor is missing the optional signature
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* <p>
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* No way to adapt the technique in this test to get a ZIP64 zip file
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* without data descriptors was found.
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*
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* @ignore 8303920 This test has brittle dependencies on an external working python.
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* @run junit DataDescriptorSignatureMissing
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*/
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import org.junit.jupiter.api.Test;
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import java.io.*;
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import java.nio.ByteBuffer;
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import java.nio.ByteOrder;
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import java.nio.charset.StandardCharsets;
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import java.util.zip.*;
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public class DataDescriptorSignatureMissing {
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void printStream(InputStream is) throws IOException {
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Reader r = new InputStreamReader(is);
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StringBuilder sb = new StringBuilder();
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char[] buf = new char[1024];
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int n;
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while ((n = r.read(buf)) > 0) {
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sb.append(buf, 0, n);
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}
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System.out.print(sb);
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}
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import static org.junit.jupiter.api.Assertions.*;
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public class DataDescriptorSignatureMissing {
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/**
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* Verify that ZipInputStream correctly parses a ZIP with a Data Descriptor without
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* the recommended but optional signature.
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*/
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@Test
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public void shouldParseSignaturelessDescriptor() throws IOException {
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// The ZIP with a signature-less descriptor
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byte[] zip = makeZipWithSignaturelessDescriptor();
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int entryCount(File zipFile) throws IOException {
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try (FileInputStream fis = new FileInputStream(zipFile);
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ZipInputStream zis = new ZipInputStream(fis)) {
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for (int count = 0;; count++)
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if (zis.getNextEntry() == null)
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return count;
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// ZipInputStream should read the signature-less data descriptor
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try (ZipInputStream in = new ZipInputStream(
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new ByteArrayInputStream(zip))) {
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ZipEntry first = in.getNextEntry();
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assertNotNull(first, "Zip file is unexpectedly missing first entry");
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assertEquals("first", first.getName());
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assertArrayEquals("first".getBytes(StandardCharsets.UTF_8), in.readAllBytes());
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ZipEntry second = in.getNextEntry();
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assertNotNull(second, "Zip file is unexpectedly missing second entry");
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assertEquals("second", second.getName());
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assertArrayEquals("second".getBytes(StandardCharsets.UTF_8), in.readAllBytes());
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}
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}
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void test(String[] args) throws Throwable {
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if (! new File("/usr/bin/python").canExecute())
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return;
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// Create a java zip file with DEFLATED entries and data
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// descriptors with signatures.
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final File in = new File("in.zip");
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final File out = new File("out.zip");
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final int count = 3;
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try (FileOutputStream fos = new FileOutputStream(in);
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ZipOutputStream zos = new ZipOutputStream(fos)) {
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for (int i = 0; i < count; i++) {
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ZipEntry ze = new ZipEntry("hello.python" + i);
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ze.setMethod(ZipEntry.DEFLATED);
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zos.putNextEntry(ze);
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zos.write(new byte[10]);
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zos.closeEntry();
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}
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/**
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* The 'Data descriptor' record is used to facilitate ZIP streaming. If the size of an
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* entry is unknown at the time the LOC header is written, bit 3 of the General Purpose Bit Flag
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* is set, and the File data is immediately followed by the 'Data descriptor' record. This record
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* then contains the compressed and uncompressed sizes of the entry and also the CRC value.
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*
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* The 'Data descriptor' record is usually preceded by the recommended, but optional
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* signature value 0x08074b50.
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*
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* A ZIP entry in streaming mode has the following structure:
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*
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* ------ Local File Header ------
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* 000000 signature 0x04034b50
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* 000004 version 20
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* 000006 flags 0x0808 # Notice bit 3 is set
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* [..] Omitted for brevity
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*
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* ------ File Data ------
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* 000035 data 7 bytes
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*
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* ------ Data Descriptor ------
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* 000042 signature 0x08074b50
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* 000046 crc 0x3610a686
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* 000050 csize 7
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* 000054 size 5
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*
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* A signature-less data descriptor will look like the following:
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*
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* ------ Data Descriptor ------
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* 000042 crc 0x3610a686
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* 000046 csize 7
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* 000050 size 5
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*
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* This method produces a ZIP with two entries, where the first entry
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* is made signature-less.
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*/
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private static byte[] makeZipWithSignaturelessDescriptor() throws IOException {
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// Offset of the signed data descriptor
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int sigOffset;
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ByteArrayOutputStream out = new ByteArrayOutputStream();
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try (ZipOutputStream zo = new ZipOutputStream(out)) {
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// Write a first entry
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zo.putNextEntry(new ZipEntry("first"));
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zo.write("first".getBytes(StandardCharsets.UTF_8));
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// Force the data descriptor to be written out
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zo.closeEntry();
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// Signed data descriptor starts 16 bytes before current offset
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sigOffset = out.size() - 4 * Integer.BYTES;
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// Add a second entry
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zo.putNextEntry(new ZipEntry("second"));
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zo.write("second".getBytes(StandardCharsets.UTF_8));
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}
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// Copy the zip file using python's zipfile module
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String[] python_program_lines = {
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"import os",
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"import zipfile",
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"input_zip = zipfile.ZipFile('in.zip', mode='r')",
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"output_zip = zipfile.ZipFile('out.zip', mode='w')",
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"count08 = 0",
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"for input_info in input_zip.infolist():",
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" output_info = input_info",
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" if output_info.flag_bits & 0x08 == 0x08:",
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" count08 += 1",
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" output_zip.writestr(output_info, input_zip.read(input_info))",
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"output_zip.close()",
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"if count08 == 0:",
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" raise ValueError('Expected to see entries with 0x08 flag_bits set')",
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};
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StringBuilder python_program_builder = new StringBuilder();
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for (String line : python_program_lines)
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python_program_builder.append(line).append('\n');
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String python_program = python_program_builder.toString();
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String[] cmdline = { "/usr/bin/python", "-c", python_program };
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ProcessBuilder pb = new ProcessBuilder(cmdline);
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pb.redirectErrorStream(true);
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Process p = pb.start();
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printStream(p.getInputStream());
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p.waitFor();
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equal(p.exitValue(), 0);
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File pythonZipFile = new File("out.zip");
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check(pythonZipFile.exists());
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equal(entryCount(in),
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entryCount(out));
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// We expect out to be identical to in, except for the removal of
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// the optional data descriptor signatures.
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final int SIG_LENGTH = 4; // length of a zip signature - PKxx
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equal(in.length(),
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out.length() + SIG_LENGTH * count);
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in.delete();
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out.delete();
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}
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// The generated ZIP file with a signed data descriptor
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byte[] sigZip = out.toByteArray();
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// The offset of the CRC immediately following the 4-byte signature
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int crcOffset = sigOffset + Integer.BYTES;
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// Create a ZIP file with a signature-less data descriptor for the first entry
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ByteArrayOutputStream sigLess = new ByteArrayOutputStream();
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sigLess.write(sigZip, 0, sigOffset);
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// Skip the signature
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sigLess.write(sigZip, crcOffset, sigZip.length - crcOffset);
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byte[] siglessZip = sigLess.toByteArray();
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//--------------------- Infrastructure ---------------------------
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volatile int passed = 0, failed = 0;
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void pass() {passed++;}
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void fail() {failed++; Thread.dumpStack();}
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void fail(String msg) {System.err.println(msg); fail();}
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void unexpected(Throwable t) {failed++; t.printStackTrace();}
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void check(boolean cond) {if (cond) pass(); else fail();}
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void equal(Object x, Object y) {
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if (x == null ? y == null : x.equals(y)) pass();
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else fail(x + " not equal to " + y);}
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public static void main(String[] args) throws Throwable {
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new DataDescriptorSignatureMissing().instanceMain(args);}
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public void instanceMain(String[] args) throws Throwable {
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try {test(args);} catch (Throwable t) {unexpected(t);}
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System.out.printf("%nPassed = %d, failed = %d%n%n", passed, failed);
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if (failed > 0) throw new AssertionError("Some tests failed");}
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// Adjust the CEN offset in the END header
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ByteBuffer buffer = ByteBuffer.wrap(siglessZip).order(ByteOrder.LITTLE_ENDIAN);
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// Reduce cenOffset by 4 bytes
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int cenOff = siglessZip.length - ZipFile.ENDHDR + ZipFile.ENDOFF;
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int realCenOff = buffer.getInt(cenOff) - Integer.BYTES;
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buffer.putInt(cenOff, realCenOff);
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// Adjust the LOC offset in the second CEN header
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int cen = realCenOff;
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// Skip past the first CEN header
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int nlen = buffer.getShort(cen + ZipFile.CENNAM);
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cen += ZipFile.CENHDR + nlen;
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// Reduce LOC offset by 4 bytes
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int locOff = cen + ZipFile.CENOFF;
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buffer.putInt(locOff, buffer.getInt(locOff) - Integer.BYTES);
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return siglessZip;
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}
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}

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