1/*
2 * Copyright (c) 2001, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 */
23
24/* @test
25 * @bug 4450867
26 * @summary Although technically the behavior of ObjectInputStream following a
27 *          UTFDataFormatException is unspecified, verify that
28 *          ObjectInputStream consumes at most the expected number of utf
29 *          bytes, even if the last byte(s) of the utf string indicate that the
30 *          string overflows its expected length.
31 * @key randomness
32 */
33
34import java.io.*;
35import java.util.Random;
36
37public class CorruptedUTFConsumption {
38
39    static Random rand = new Random(System.currentTimeMillis());
40
41    public static void main(String[] args) throws Exception {
42        StringBuffer sbuf = new StringBuffer();
43        ByteArrayOutputStream bout = new ByteArrayOutputStream();
44        DataOutputStream dout = new DataOutputStream(bout);
45
46        for (int i = 0; i < 1200; i++) {
47            sbuf.append(i % 10);
48            bout.reset();
49            dout.writeUTF(sbuf.toString());
50            byte[] utf = bout.toByteArray();
51
52            // set last byte to first byte of 2-char sequence
53            utf[utf.length - 1] = (byte) (0xC0 | rand.nextInt() & 0x1F);
54            checkConsume(utf);
55
56            // set last byte to first byte of 3-char sequence
57            utf[utf.length - 1] = (byte) (0xE0 | rand.nextInt() & 0x0F);
58            checkConsume(utf);
59
60            if (utf.length >= 4) {      // don't touch utf length bytes
61                // set last 2 bytes to first, second byte of 3-char sequence
62                utf[utf.length - 2] = (byte) (0xE0 | rand.nextInt() & 0x0F);
63                utf[utf.length - 1] = (byte) (0x80 | rand.nextInt() & 0x3F);
64                checkConsume(utf);
65            }
66        }
67    }
68
69    static void checkConsume(byte[] utf) throws Exception {
70        ByteArrayOutputStream bout = new ByteArrayOutputStream();
71        ObjectOutputStream oout = new ObjectOutputStream(bout);
72        oout.write(utf);
73        oout.writeByte(0);      // leave one byte of padding
74        oout.close();
75        ObjectInputStream oin = new ObjectInputStream(
76            new ByteArrayInputStream(bout.toByteArray()));
77        try {
78            oin.readUTF();
79            throw new Error();
80        } catch (UTFDataFormatException ex) {
81        }
82        // if readUTF consumed padding byte, readByte will throw EOFException
83        oin.readByte();
84    }
85}
86