test_write_disk_secure746.c revision 306321 
1/*-
2 * Copyright (c) 2003-2007,2016 Tim Kientzle
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17 * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25#include "test.h"
26__FBSDID("$FreeBSD: stable/11/contrib/libarchive/libarchive/test/test_write_disk_secure746.c 306321 2016-09-25 22:02:27Z mm $");
27
28#define UMASK 022
29
30/*
31 * Github Issue #746 describes a problem in which hardlink targets are
32 * not adequately checked and can be used to modify entries outside of
33 * the sandbox.
34 */
35
36/*
37 * Verify that ARCHIVE_EXTRACT_SECURE_NODOTDOT disallows '..' in hardlink
38 * targets.
39 */
40DEFINE_TEST(test_write_disk_secure746a)
41{
42#if defined(_WIN32) && !defined(__CYGWIN__)
43	skipping("archive_write_disk security checks not supported on Windows");
44#else
45	struct archive *a;
46	struct archive_entry *ae;
47
48	/* Start with a known umask. */
49	assertUmask(UMASK);
50
51	/* The target directory we're going to try to affect. */
52	assertMakeDir("target", 0700);
53	assertMakeFile("target/foo", 0700, "unmodified");
54
55	/* The sandbox dir we're going to work within. */
56	assertMakeDir("sandbox", 0700);
57	assertChdir("sandbox");
58
59	/* Create an archive_write_disk object. */
60	assert((a = archive_write_disk_new()) != NULL);
61	archive_write_disk_set_options(a, ARCHIVE_EXTRACT_SECURE_NODOTDOT);
62
63	/* Attempt to hardlink to the target directory. */
64	assert((ae = archive_entry_new()) != NULL);
65	archive_entry_copy_pathname(ae, "bar");
66	archive_entry_set_mode(ae, AE_IFREG | 0777);
67	archive_entry_set_size(ae, 8);
68	archive_entry_copy_hardlink(ae, "../target/foo");
69	assertEqualInt(ARCHIVE_FAILED, archive_write_header(a, ae));
70	assertEqualInt(ARCHIVE_FATAL, archive_write_data(a, "modified", 8));
71	archive_entry_free(ae);
72
73	/* Verify that target file contents are unchanged. */
74	assertTextFileContents("unmodified", "../target/foo");
75#endif
76}
77
78/*
79 * Verify that ARCHIVE_EXTRACT_SECURE_NOSYMLINK disallows symlinks in hardlink
80 * targets.
81 */
82DEFINE_TEST(test_write_disk_secure746b)
83{
84#if defined(_WIN32) && !defined(__CYGWIN__)
85	skipping("archive_write_disk security checks not supported on Windows");
86#else
87	struct archive *a;
88	struct archive_entry *ae;
89
90	/* Start with a known umask. */
91	assertUmask(UMASK);
92
93	/* The target directory we're going to try to affect. */
94	assertMakeDir("target", 0700);
95	assertMakeFile("target/foo", 0700, "unmodified");
96
97	/* The sandbox dir we're going to work within. */
98	assertMakeDir("sandbox", 0700);
99	assertChdir("sandbox");
100
101	/* Create an archive_write_disk object. */
102	assert((a = archive_write_disk_new()) != NULL);
103	archive_write_disk_set_options(a, ARCHIVE_EXTRACT_SECURE_SYMLINKS);
104
105	/* Create a symlink to the target directory. */
106	assert((ae = archive_entry_new()) != NULL);
107	archive_entry_copy_pathname(ae, "symlink");
108	archive_entry_set_mode(ae, AE_IFLNK | 0777);
109	archive_entry_copy_symlink(ae, "../target");
110	assertEqualIntA(a, ARCHIVE_OK, archive_write_header(a, ae));
111	archive_entry_free(ae);
112
113	/* Attempt to hardlink to the target directory via the symlink. */
114	assert((ae = archive_entry_new()) != NULL);
115	archive_entry_copy_pathname(ae, "bar");
116	archive_entry_set_mode(ae, AE_IFREG | 0777);
117	archive_entry_set_size(ae, 8);
118	archive_entry_copy_hardlink(ae, "symlink/foo");
119	assertEqualIntA(a, ARCHIVE_FAILED, archive_write_header(a, ae));
120	assertEqualIntA(a, ARCHIVE_FATAL, archive_write_data(a, "modified", 8));
121	archive_entry_free(ae);
122
123	/* Verify that target file contents are unchanged. */
124	assertTextFileContents("unmodified", "../target/foo");
125
126	assertEqualIntA(a, ARCHIVE_FATAL, archive_write_close(a));
127	archive_write_free(a);
128#endif
129}
130