test_write_disk_secure746.c revision 313570 
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 313570 2017-02-11 00:54:16Z 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
76	assertEqualIntA(a, ARCHIVE_FATAL, archive_write_close(a));
77	archive_write_free(a);
78#endif
79}
80
81/*
82 * Verify that ARCHIVE_EXTRACT_SECURE_NOSYMLINK disallows symlinks in hardlink
83 * targets.
84 */
85DEFINE_TEST(test_write_disk_secure746b)
86{
87#if defined(_WIN32) && !defined(__CYGWIN__)
88	skipping("archive_write_disk security checks not supported on Windows");
89#else
90	struct archive *a;
91	struct archive_entry *ae;
92
93	/* Start with a known umask. */
94	assertUmask(UMASK);
95
96	/* The target directory we're going to try to affect. */
97	assertMakeDir("target", 0700);
98	assertMakeFile("target/foo", 0700, "unmodified");
99
100	/* The sandbox dir we're going to work within. */
101	assertMakeDir("sandbox", 0700);
102	assertChdir("sandbox");
103
104	/* Create an archive_write_disk object. */
105	assert((a = archive_write_disk_new()) != NULL);
106	archive_write_disk_set_options(a, ARCHIVE_EXTRACT_SECURE_SYMLINKS);
107
108	/* Create a symlink to the target directory. */
109	assert((ae = archive_entry_new()) != NULL);
110	archive_entry_copy_pathname(ae, "symlink");
111	archive_entry_set_mode(ae, AE_IFLNK | 0777);
112	archive_entry_copy_symlink(ae, "../target");
113	assertEqualIntA(a, ARCHIVE_OK, archive_write_header(a, ae));
114	archive_entry_free(ae);
115
116	/* Attempt to hardlink to the target directory via the symlink. */
117	assert((ae = archive_entry_new()) != NULL);
118	archive_entry_copy_pathname(ae, "bar");
119	archive_entry_set_mode(ae, AE_IFREG | 0777);
120	archive_entry_set_size(ae, 8);
121	archive_entry_copy_hardlink(ae, "symlink/foo");
122	assertEqualIntA(a, ARCHIVE_FAILED, archive_write_header(a, ae));
123	assertEqualIntA(a, ARCHIVE_FATAL, archive_write_data(a, "modified", 8));
124	archive_entry_free(ae);
125
126	/* Verify that target file contents are unchanged. */
127	assertTextFileContents("unmodified", "../target/foo");
128
129	assertEqualIntA(a, ARCHIVE_FATAL, archive_write_close(a));
130	archive_write_free(a);
131#endif
132}
133