test_write_disk_secure.c revision 302001
1/*-
2 * Copyright (c) 2003-2007 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/10/contrib/libarchive/libarchive/test/test_write_disk_secure.c 302001 2016-06-17 22:40:10Z mm $");
27
28#define UMASK 022
29
30/*
31 * Exercise security checks that should prevent certain
32 * writes.
33 */
34
35DEFINE_TEST(test_write_disk_secure)
36{
37#if defined(_WIN32) && !defined(__CYGWIN__)
38	skipping("archive_write_disk security checks not supported on Windows");
39#else
40	struct archive *a;
41	struct archive_entry *ae;
42	struct stat st;
43
44	/* Start with a known umask. */
45	assertUmask(UMASK);
46
47	/* Create an archive_write_disk object. */
48	assert((a = archive_write_disk_new()) != NULL);
49
50	/* Write a regular dir to it. */
51	assert((ae = archive_entry_new()) != NULL);
52	archive_entry_copy_pathname(ae, "dir");
53	archive_entry_set_mode(ae, S_IFDIR | 0777);
54	assert(0 == archive_write_header(a, ae));
55	archive_entry_free(ae);
56	assert(0 == archive_write_finish_entry(a));
57
58	/* Write a symlink to the dir above. */
59	assert((ae = archive_entry_new()) != NULL);
60	archive_entry_copy_pathname(ae, "link_to_dir");
61	archive_entry_set_mode(ae, S_IFLNK | 0777);
62	archive_entry_set_symlink(ae, "dir");
63	archive_write_disk_set_options(a, 0);
64	assert(0 == archive_write_header(a, ae));
65	assert(0 == archive_write_finish_entry(a));
66
67	/*
68	 * Without security checks, we should be able to
69	 * extract a file through the link.
70	 */
71	assert(archive_entry_clear(ae) != NULL);
72	archive_entry_copy_pathname(ae, "link_to_dir/filea");
73	archive_entry_set_mode(ae, S_IFREG | 0777);
74	assert(0 == archive_write_header(a, ae));
75	assert(0 == archive_write_finish_entry(a));
76
77	/* But with security checks enabled, this should fail. */
78	assert(archive_entry_clear(ae) != NULL);
79	archive_entry_copy_pathname(ae, "link_to_dir/fileb");
80	archive_entry_set_mode(ae, S_IFREG | 0777);
81	archive_write_disk_set_options(a, ARCHIVE_EXTRACT_SECURE_SYMLINKS);
82	failure("Extracting a file through a symlink should fail here.");
83	assertEqualInt(ARCHIVE_FAILED, archive_write_header(a, ae));
84	archive_entry_free(ae);
85	assert(0 == archive_write_finish_entry(a));
86
87	/* Write an absolute symlink to /tmp. */
88	assert((ae = archive_entry_new()) != NULL);
89	archive_entry_copy_pathname(ae, "/tmp/libarchive_test-test_write_disk_secure-absolute_symlink");
90	archive_entry_set_mode(ae, S_IFLNK | 0777);
91	archive_entry_set_symlink(ae, "/tmp");
92	archive_write_disk_set_options(a, 0);
93	assert(0 == archive_write_header(a, ae));
94	assert(0 == archive_write_finish_entry(a));
95
96	/* With security checks enabled, this should fail. */
97	assert(archive_entry_clear(ae) != NULL);
98	archive_entry_copy_pathname(ae, "/tmp/libarchive_test-test_write_disk_secure-absolute_symlink/libarchive_test-test_write_disk_secure-absolute_symlink_path.tmp");
99	archive_entry_set_mode(ae, S_IFREG | 0777);
100	archive_write_disk_set_options(a, ARCHIVE_EXTRACT_SECURE_SYMLINKS);
101	failure("Extracting a file through an absolute symlink should fail here.");
102	assertEqualInt(ARCHIVE_FAILED, archive_write_header(a, ae));
103	archive_entry_free(ae);
104	assertFileNotExists("/tmp/libarchive_test-test_write_disk_secure-absolute_symlink/libarchive_test-test_write_disk_secure-absolute_symlink_path.tmp");
105	assert(0 == unlink("/tmp/libarchive_test-test_write_disk_secure-absolute_symlink"));
106	unlink("/tmp/libarchive_test-test_write_disk_secure-absolute_symlink_path.tmp");
107
108	/* Create another link. */
109	assert((ae = archive_entry_new()) != NULL);
110	archive_entry_copy_pathname(ae, "link_to_dir2");
111	archive_entry_set_mode(ae, S_IFLNK | 0777);
112	archive_entry_set_symlink(ae, "dir");
113	archive_write_disk_set_options(a, 0);
114	assert(0 == archive_write_header(a, ae));
115	assert(0 == archive_write_finish_entry(a));
116
117	/*
118	 * With symlink check and unlink option, it should remove
119	 * the link and create the dir.
120	 */
121	assert(archive_entry_clear(ae) != NULL);
122	archive_entry_copy_pathname(ae, "link_to_dir2/filec");
123	archive_entry_set_mode(ae, S_IFREG | 0777);
124	archive_write_disk_set_options(a, ARCHIVE_EXTRACT_SECURE_SYMLINKS | ARCHIVE_EXTRACT_UNLINK);
125	assertEqualIntA(a, ARCHIVE_OK, archive_write_header(a, ae));
126	archive_entry_free(ae);
127	assert(0 == archive_write_finish_entry(a));
128
129	/* Create a nested symlink. */
130	assert((ae = archive_entry_new()) != NULL);
131	archive_entry_copy_pathname(ae, "dir/nested_link_to_dir");
132	archive_entry_set_mode(ae, S_IFLNK | 0777);
133	archive_entry_set_symlink(ae, "../dir");
134	archive_write_disk_set_options(a, 0);
135	assert(0 == archive_write_header(a, ae));
136	assert(0 == archive_write_finish_entry(a));
137
138	/* But with security checks enabled, this should fail. */
139	assert(archive_entry_clear(ae) != NULL);
140	archive_entry_copy_pathname(ae, "dir/nested_link_to_dir/filed");
141	archive_entry_set_mode(ae, S_IFREG | 0777);
142	archive_write_disk_set_options(a, ARCHIVE_EXTRACT_SECURE_SYMLINKS);
143	failure("Extracting a file through a symlink should fail here.");
144	assertEqualInt(ARCHIVE_FAILED, archive_write_header(a, ae));
145	archive_entry_free(ae);
146	assert(0 == archive_write_finish_entry(a));
147
148	/*
149	 * Without security checks, extracting a dir over a link to a
150	 * dir should follow the link.
151	 */
152	/* Create a symlink to a dir. */
153	assert((ae = archive_entry_new()) != NULL);
154	archive_entry_copy_pathname(ae, "link_to_dir3");
155	archive_entry_set_mode(ae, S_IFLNK | 0777);
156	archive_entry_set_symlink(ae, "dir");
157	archive_write_disk_set_options(a, 0);
158	assert(0 == archive_write_header(a, ae));
159	assert(0 == archive_write_finish_entry(a));
160	/* Extract a dir whose name matches the symlink. */
161	assert(archive_entry_clear(ae) != NULL);
162	archive_entry_copy_pathname(ae, "link_to_dir3");
163	archive_entry_set_mode(ae, S_IFDIR | 0777);
164	assert(0 == archive_write_header(a, ae));
165	assert(0 == archive_write_finish_entry(a));
166	/* Verify link was followed. */
167	assertEqualInt(0, lstat("link_to_dir3", &st));
168	assert(S_ISLNK(st.st_mode));
169	archive_entry_free(ae);
170
171	/*
172	 * As above, but a broken link, so the link should get replaced.
173	 */
174	/* Create a symlink to a dir. */
175	assert((ae = archive_entry_new()) != NULL);
176	archive_entry_copy_pathname(ae, "link_to_dir4");
177	archive_entry_set_mode(ae, S_IFLNK | 0777);
178	archive_entry_set_symlink(ae, "nonexistent_dir");
179	archive_write_disk_set_options(a, 0);
180	assert(0 == archive_write_header(a, ae));
181	assert(0 == archive_write_finish_entry(a));
182	/* Extract a dir whose name matches the symlink. */
183	assert(archive_entry_clear(ae) != NULL);
184	archive_entry_copy_pathname(ae, "link_to_dir4");
185	archive_entry_set_mode(ae, S_IFDIR | 0777);
186	assert(0 == archive_write_header(a, ae));
187	assert(0 == archive_write_finish_entry(a));
188	/* Verify link was replaced. */
189	assertEqualInt(0, lstat("link_to_dir4", &st));
190	assert(S_ISDIR(st.st_mode));
191	archive_entry_free(ae);
192
193	/*
194	 * As above, but a link to a non-dir, so the link should get replaced.
195	 */
196	/* Create a regular file and a symlink to it */
197	assert((ae = archive_entry_new()) != NULL);
198	archive_entry_copy_pathname(ae, "non_dir");
199	archive_entry_set_mode(ae, S_IFREG | 0777);
200	archive_write_disk_set_options(a, 0);
201	assert(0 == archive_write_header(a, ae));
202	assert(0 == archive_write_finish_entry(a));
203	/* Create symlink to the file. */
204	archive_entry_copy_pathname(ae, "link_to_dir5");
205	archive_entry_set_mode(ae, S_IFLNK | 0777);
206	archive_entry_set_symlink(ae, "non_dir");
207	archive_write_disk_set_options(a, 0);
208	assert(0 == archive_write_header(a, ae));
209	assert(0 == archive_write_finish_entry(a));
210	/* Extract a dir whose name matches the symlink. */
211	assert(archive_entry_clear(ae) != NULL);
212	archive_entry_copy_pathname(ae, "link_to_dir5");
213	archive_entry_set_mode(ae, S_IFDIR | 0777);
214	assert(0 == archive_write_header(a, ae));
215	assert(0 == archive_write_finish_entry(a));
216	/* Verify link was replaced. */
217	assertEqualInt(0, lstat("link_to_dir5", &st));
218	assert(S_ISDIR(st.st_mode));
219	archive_entry_free(ae);
220
221	/*
222	 * Without security checks, we should be able to
223	 * extract an absolute path.
224	 */
225	assert((ae = archive_entry_new()) != NULL);
226	archive_entry_copy_pathname(ae, "/tmp/libarchive_test-test_write_disk_secure-absolute_path.tmp");
227	archive_entry_set_mode(ae, S_IFREG | 0777);
228	assert(0 == archive_write_header(a, ae));
229	assert(0 == archive_write_finish_entry(a));
230	assertFileExists("/tmp/libarchive_test-test_write_disk_secure-absolute_path.tmp");
231	assert(0 == unlink("/tmp/libarchive_test-test_write_disk_secure-absolute_path.tmp"));
232
233	/* But with security checks enabled, this should fail. */
234	assert(archive_entry_clear(ae) != NULL);
235	archive_entry_copy_pathname(ae, "/tmp/libarchive_test-test_write_disk_secure-absolute_path.tmp");
236	archive_entry_set_mode(ae, S_IFREG | 0777);
237	archive_write_disk_set_options(a, ARCHIVE_EXTRACT_SECURE_NOABSOLUTEPATHS);
238	failure("Extracting an absolute path should fail here.");
239	assertEqualInt(ARCHIVE_FAILED, archive_write_header(a, ae));
240	archive_entry_free(ae);
241	assert(0 == archive_write_finish_entry(a));
242	assertFileNotExists("/tmp/libarchive_test-test_write_disk_secure-absolute_path.tmp");
243
244	assertEqualInt(ARCHIVE_OK, archive_write_free(a));
245
246	/* Test the entries on disk. */
247	assert(0 == lstat("dir", &st));
248	failure("dir: st.st_mode=%o", st.st_mode);
249	assert((st.st_mode & 0777) == 0755);
250
251	assert(0 == lstat("link_to_dir", &st));
252	failure("link_to_dir: st.st_mode=%o", st.st_mode);
253	assert(S_ISLNK(st.st_mode));
254#if HAVE_LCHMOD
255	/* Systems that lack lchmod() can't set symlink perms, so skip this. */
256	failure("link_to_dir: st.st_mode=%o", st.st_mode);
257	assert((st.st_mode & 07777) == 0755);
258#endif
259
260	assert(0 == lstat("dir/filea", &st));
261	failure("dir/filea: st.st_mode=%o", st.st_mode);
262	assert((st.st_mode & 07777) == 0755);
263
264	failure("dir/fileb: This file should not have been created");
265	assert(0 != lstat("dir/fileb", &st));
266
267	assert(0 == lstat("link_to_dir2", &st));
268	failure("link_to_dir2 should have been re-created as a true dir");
269	assert(S_ISDIR(st.st_mode));
270	failure("link_to_dir2: Implicit dir creation should obey umask, but st.st_mode=%o", st.st_mode);
271	assert((st.st_mode & 0777) == 0755);
272
273	assert(0 == lstat("link_to_dir2/filec", &st));
274	assert(S_ISREG(st.st_mode));
275	failure("link_to_dir2/filec: st.st_mode=%o", st.st_mode);
276	assert((st.st_mode & 07777) == 0755);
277
278	failure("dir/filed: This file should not have been created");
279	assert(0 != lstat("dir/filed", &st));
280#endif
281}
282