changeset 10666:24d6f3d22cd8

8056934: ZipInputStream does not correctly handle local header data descriptors with the optional signature missing Summary: fix off-by-one bug in EXTSIG handling; add docs. Reviewed-by: sherman, alanb
author martin
date Fri, 29 Aug 2014 12:07:11 -0700
parents fb6b143641fd
children 0b880663fd81
files src/java.base/share/classes/java/util/zip/ZipInputStream.java test/java/util/zip/DataDescriptorSignatureMissing.java
diffstat 2 files changed, 163 insertions(+), 3 deletions(-) [+]
line wrap: on
line diff
--- a/src/java.base/share/classes/java/util/zip/ZipInputStream.java	Fri Sep 12 13:08:35 2014 -0700
+++ b/src/java.base/share/classes/java/util/zip/ZipInputStream.java	Fri Aug 29 12:07:11 2014 -0700
@@ -336,8 +336,21 @@
         return new ZipEntry(name);
     }
 
-    /*
+    /**
      * Reads end of deflated entry as well as EXT descriptor if present.
+     *
+     * Local headers for DEFLATED entries may optionally be followed by a
+     * data descriptor, and that data descriptor may optionally contain a
+     * leading signature (EXTSIG).
+     *
+     * From the zip spec http://www.pkware.com/documents/casestudies/APPNOTE.TXT
+     *
+     * """Although not originally assigned a signature, the value 0x08074b50
+     * has commonly been adopted as a signature value for the data descriptor
+     * record.  Implementers should be aware that ZIP files may be
+     * encountered with or without this signature marking data descriptors
+     * and should account for either case when reading ZIP files to ensure
+     * compatibility."""
      */
     private void readEnd(ZipEntry e) throws IOException {
         int n = inf.getRemaining();
@@ -356,7 +369,7 @@
                     e.csize = get64(tmpbuf, ZIP64_EXTSIZ - ZIP64_EXTCRC);
                     e.size = get64(tmpbuf, ZIP64_EXTLEN - ZIP64_EXTCRC);
                     ((PushbackInputStream)in).unread(
-                        tmpbuf, ZIP64_EXTHDR - ZIP64_EXTCRC - 1, ZIP64_EXTCRC);
+                        tmpbuf, ZIP64_EXTHDR - ZIP64_EXTCRC, ZIP64_EXTCRC);
                 } else {
                     e.crc = get32(tmpbuf, ZIP64_EXTCRC);
                     e.csize = get64(tmpbuf, ZIP64_EXTSIZ);
@@ -370,7 +383,7 @@
                     e.csize = get32(tmpbuf, EXTSIZ - EXTCRC);
                     e.size = get32(tmpbuf, EXTLEN - EXTCRC);
                     ((PushbackInputStream)in).unread(
-                                               tmpbuf, EXTHDR - EXTCRC - 1, EXTCRC);
+                                               tmpbuf, EXTHDR - EXTCRC, EXTCRC);
                 } else {
                     e.crc = get32(tmpbuf, EXTCRC);
                     e.csize = get32(tmpbuf, EXTSIZ);
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/java/util/zip/DataDescriptorSignatureMissing.java	Fri Aug 29 12:07:11 2014 -0700
@@ -0,0 +1,147 @@
+/*
+ * Copyright 2012 Google, Inc.  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 8056934
+ * @summary Check ability to read zip files created by python zipfile
+ * implementation, which fails to write optional (but recommended) data
+ * descriptor signatures.  Repro scenario is a Java -> Python -> Java round trip:
+ * - ZipOutputStream creates zip file with DEFLATED entries and data
+ *   descriptors with optional signature "PK0x0708".
+ * - Python reads those entries, preserving the 0x08 flag byte
+ * - Python outputs those entries with data descriptors lacking the
+ *   optional signature.
+ * - ZipInputStream cannot handle the missing signature
+ *
+ * No way to adapt the technique in this test to get a ZIP64 zip file
+ * without data descriptors was found.
+ *
+ * @ignore This test has brittle dependencies on an external working python.
+ */
+
+import java.io.*;
+import java.util.zip.*;
+
+public class DataDescriptorSignatureMissing  {
+    void printStream(InputStream is) throws IOException {
+        Reader r = new InputStreamReader(is);
+        StringBuilder sb = new StringBuilder();
+        char[] buf = new char[1024];
+        int n;
+        while ((n = r.read(buf)) > 0) {
+            sb.append(buf, 0, n);
+        }
+        System.out.print(sb);
+    }
+
+    int entryCount(File zipFile) throws IOException {
+        try (FileInputStream fis = new FileInputStream(zipFile);
+             ZipInputStream zis = new ZipInputStream(fis)) {
+            for (int count = 0;; count++)
+                if (zis.getNextEntry() == null)
+                    return count;
+        }
+    }
+
+    void test(String[] args) throws Throwable {
+        if (! new File("/usr/bin/python").canExecute())
+            return;
+
+        // Create a java zip file with DEFLATED entries and data
+        // descriptors with signatures.
+        final File in = new File("in.zip");
+        final File out = new File("out.zip");
+        final int count = 3;
+        try (FileOutputStream fos = new FileOutputStream(in);
+             ZipOutputStream zos = new ZipOutputStream(fos)) {
+            for (int i = 0; i < count; i++) {
+                ZipEntry ze = new ZipEntry("hello.python" + i);
+                ze.setMethod(ZipEntry.DEFLATED);
+                zos.putNextEntry(ze);
+                zos.write(new byte[10]);
+                zos.closeEntry();
+            }
+        }
+
+        // Copy the zip file using python's zipfile module
+        String[] python_program_lines = {
+            "import os",
+            "import zipfile",
+            "input_zip = zipfile.ZipFile('in.zip', mode='r')",
+            "output_zip = zipfile.ZipFile('out.zip', mode='w')",
+            "count08 = 0",
+            "for input_info in input_zip.infolist():",
+            "  output_info = input_info",
+            "  if output_info.flag_bits & 0x08 == 0x08:",
+            "    count08 += 1",
+            "  output_zip.writestr(output_info, input_zip.read(input_info))",
+            "output_zip.close()",
+            "if count08 == 0:",
+            "  raise ValueError('Expected to see entries with 0x08 flag_bits set')",
+        };
+        StringBuilder python_program_builder = new StringBuilder();
+        for (String line : python_program_lines)
+            python_program_builder.append(line).append('\n');
+        String python_program = python_program_builder.toString();
+        String[] cmdline = { "/usr/bin/python", "-c", python_program };
+        ProcessBuilder pb = new ProcessBuilder(cmdline);
+        pb.redirectErrorStream(true);
+        Process p = pb.start();
+        printStream(p.getInputStream());
+        p.waitFor();
+        equal(p.exitValue(), 0);
+
+        File pythonZipFile = new File("out.zip");
+        check(pythonZipFile.exists());
+
+        equal(entryCount(in),
+              entryCount(out));
+
+        // We expect out to be identical to in, except for the removal of
+        // the optional data descriptor signatures.
+        final int SIG_LENGTH = 4;       // length of a zip signature - PKxx
+        equal(in.length(),
+              out.length() + SIG_LENGTH * count);
+
+        in.delete();
+        out.delete();
+    }
+
+    //--------------------- Infrastructure ---------------------------
+    volatile int passed = 0, failed = 0;
+    void pass() {passed++;}
+    void fail() {failed++; Thread.dumpStack();}
+    void fail(String msg) {System.err.println(msg); fail();}
+    void unexpected(Throwable t) {failed++; t.printStackTrace();}
+    void check(boolean cond) {if (cond) pass(); else fail();}
+    void equal(Object x, Object y) {
+        if (x == null ? y == null : x.equals(y)) pass();
+        else fail(x + " not equal to " + y);}
+    public static void main(String[] args) throws Throwable {
+        new DataDescriptorSignatureMissing().instanceMain(args);}
+    public void instanceMain(String[] args) throws Throwable {
+        try {test(args);} catch (Throwable t) {unexpected(t);}
+        System.out.printf("%nPassed = %d, failed = %d%n%n", passed, failed);
+        if (failed > 0) throw new AssertionError("Some tests failed");}
+}