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("$FreeBSD$");
27
28 #define UMASK 022
29
30 /*
31 * Exercise security checks that should prevent certain
32 * writes.
33 */
34
DEFINE_TEST(test_write_disk_secure)35 DEFINE_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 #if defined(HAVE_LCHMOD) && defined(HAVE_SYMLINK) && \
44 defined(S_IRUSR) && defined(S_IWUSR) && defined(S_IXUSR)
45 int working_lchmod;
46 #endif
47
48 /* Start with a known umask. */
49 assertUmask(UMASK);
50
51 /* Create an archive_write_disk object. */
52 assert((a = archive_write_disk_new()) != NULL);
53
54 /* Write a regular dir to it. */
55 assert((ae = archive_entry_new()) != NULL);
56 archive_entry_copy_pathname(ae, "dir");
57 archive_entry_set_mode(ae, S_IFDIR | 0777);
58 assert(0 == archive_write_header(a, ae));
59 archive_entry_free(ae);
60 assert(0 == archive_write_finish_entry(a));
61
62 /* Write a symlink to the dir above. */
63 assert((ae = archive_entry_new()) != NULL);
64 archive_entry_copy_pathname(ae, "link_to_dir");
65 archive_entry_set_mode(ae, S_IFLNK | 0777);
66 archive_entry_set_symlink(ae, "dir");
67 archive_write_disk_set_options(a, 0);
68 assert(0 == archive_write_header(a, ae));
69 assert(0 == archive_write_finish_entry(a));
70
71 /*
72 * Without security checks, we should be able to
73 * extract a file through the link.
74 */
75 assert(archive_entry_clear(ae) != NULL);
76 archive_entry_copy_pathname(ae, "link_to_dir/filea");
77 archive_entry_set_mode(ae, S_IFREG | 0777);
78 assert(0 == archive_write_header(a, ae));
79 assert(0 == archive_write_finish_entry(a));
80
81 /* But with security checks enabled, this should fail. */
82 assert(archive_entry_clear(ae) != NULL);
83 archive_entry_copy_pathname(ae, "link_to_dir/fileb");
84 archive_entry_set_mode(ae, S_IFREG | 0777);
85 archive_write_disk_set_options(a, ARCHIVE_EXTRACT_SECURE_SYMLINKS);
86 failure("Extracting a file through a symlink should fail here.");
87 assertEqualInt(ARCHIVE_FAILED, archive_write_header(a, ae));
88 archive_entry_free(ae);
89 assert(0 == archive_write_finish_entry(a));
90
91 /* Write an absolute symlink to /tmp. */
92 assert((ae = archive_entry_new()) != NULL);
93 archive_entry_copy_pathname(ae, "/tmp/libarchive_test-test_write_disk_secure-absolute_symlink");
94 archive_entry_set_mode(ae, S_IFLNK | 0777);
95 archive_entry_set_symlink(ae, "/tmp");
96 archive_write_disk_set_options(a, 0);
97 assert(0 == archive_write_header(a, ae));
98 assert(0 == archive_write_finish_entry(a));
99
100 /* With security checks enabled, this should fail. */
101 assert(archive_entry_clear(ae) != NULL);
102 archive_entry_copy_pathname(ae, "/tmp/libarchive_test-test_write_disk_secure-absolute_symlink/libarchive_test-test_write_disk_secure-absolute_symlink_path.tmp");
103 archive_entry_set_mode(ae, S_IFREG | 0777);
104 archive_write_disk_set_options(a, ARCHIVE_EXTRACT_SECURE_SYMLINKS);
105 failure("Extracting a file through an absolute symlink should fail here.");
106 assertEqualInt(ARCHIVE_FAILED, archive_write_header(a, ae));
107 archive_entry_free(ae);
108 assertFileNotExists("/tmp/libarchive_test-test_write_disk_secure-absolute_symlink/libarchive_test-test_write_disk_secure-absolute_symlink_path.tmp");
109 assert(0 == unlink("/tmp/libarchive_test-test_write_disk_secure-absolute_symlink"));
110 unlink("/tmp/libarchive_test-test_write_disk_secure-absolute_symlink_path.tmp");
111
112 /* Create another link. */
113 assert((ae = archive_entry_new()) != NULL);
114 archive_entry_copy_pathname(ae, "link_to_dir2");
115 archive_entry_set_mode(ae, S_IFLNK | 0777);
116 archive_entry_set_symlink(ae, "dir");
117 archive_write_disk_set_options(a, 0);
118 assert(0 == archive_write_header(a, ae));
119 assert(0 == archive_write_finish_entry(a));
120
121 /*
122 * With symlink check and unlink option, it should remove
123 * the link and create the dir.
124 */
125 assert(archive_entry_clear(ae) != NULL);
126 archive_entry_copy_pathname(ae, "link_to_dir2/filec");
127 archive_entry_set_mode(ae, S_IFREG | 0777);
128 archive_write_disk_set_options(a, ARCHIVE_EXTRACT_SECURE_SYMLINKS | ARCHIVE_EXTRACT_UNLINK);
129 assertEqualIntA(a, ARCHIVE_OK, archive_write_header(a, ae));
130 archive_entry_free(ae);
131 assert(0 == archive_write_finish_entry(a));
132
133 /* Create a nested symlink. */
134 assert((ae = archive_entry_new()) != NULL);
135 archive_entry_copy_pathname(ae, "dir/nested_link_to_dir");
136 archive_entry_set_mode(ae, S_IFLNK | 0777);
137 archive_entry_set_symlink(ae, "../dir");
138 archive_write_disk_set_options(a, 0);
139 assert(0 == archive_write_header(a, ae));
140 assert(0 == archive_write_finish_entry(a));
141
142 /* But with security checks enabled, this should fail. */
143 assert(archive_entry_clear(ae) != NULL);
144 archive_entry_copy_pathname(ae, "dir/nested_link_to_dir/filed");
145 archive_entry_set_mode(ae, S_IFREG | 0777);
146 archive_write_disk_set_options(a, ARCHIVE_EXTRACT_SECURE_SYMLINKS);
147 failure("Extracting a file through a symlink should fail here.");
148 assertEqualInt(ARCHIVE_FAILED, archive_write_header(a, ae));
149 archive_entry_free(ae);
150 assert(0 == archive_write_finish_entry(a));
151
152 /*
153 * Without security checks, extracting a dir over a link to a
154 * dir should follow the link.
155 */
156 /* Create a symlink to a dir. */
157 assert((ae = archive_entry_new()) != NULL);
158 archive_entry_copy_pathname(ae, "link_to_dir3");
159 archive_entry_set_mode(ae, S_IFLNK | 0777);
160 archive_entry_set_symlink(ae, "dir");
161 archive_write_disk_set_options(a, 0);
162 assert(0 == archive_write_header(a, ae));
163 assert(0 == archive_write_finish_entry(a));
164 /* Extract a dir whose name matches the symlink. */
165 assert(archive_entry_clear(ae) != NULL);
166 archive_entry_copy_pathname(ae, "link_to_dir3");
167 archive_entry_set_mode(ae, S_IFDIR | 0777);
168 assert(0 == archive_write_header(a, ae));
169 assert(0 == archive_write_finish_entry(a));
170 /* Verify link was followed. */
171 assertEqualInt(0, lstat("link_to_dir3", &st));
172 assert(S_ISLNK(st.st_mode));
173 archive_entry_free(ae);
174
175 /*
176 * As above, but a broken link, so the link should get replaced.
177 */
178 /* Create a symlink to a dir. */
179 assert((ae = archive_entry_new()) != NULL);
180 archive_entry_copy_pathname(ae, "link_to_dir4");
181 archive_entry_set_mode(ae, S_IFLNK | 0777);
182 archive_entry_set_symlink(ae, "nonexistent_dir");
183 archive_write_disk_set_options(a, 0);
184 assert(0 == archive_write_header(a, ae));
185 assert(0 == archive_write_finish_entry(a));
186 /* Extract a dir whose name matches the symlink. */
187 assert(archive_entry_clear(ae) != NULL);
188 archive_entry_copy_pathname(ae, "link_to_dir4");
189 archive_entry_set_mode(ae, S_IFDIR | 0777);
190 assert(0 == archive_write_header(a, ae));
191 assert(0 == archive_write_finish_entry(a));
192 /* Verify link was replaced. */
193 assertEqualInt(0, lstat("link_to_dir4", &st));
194 assert(S_ISDIR(st.st_mode));
195 archive_entry_free(ae);
196
197 /*
198 * As above, but a link to a non-dir, so the link should get replaced.
199 */
200 /* Create a regular file and a symlink to it */
201 assert((ae = archive_entry_new()) != NULL);
202 archive_entry_copy_pathname(ae, "non_dir");
203 archive_entry_set_mode(ae, S_IFREG | 0777);
204 archive_write_disk_set_options(a, 0);
205 assert(0 == archive_write_header(a, ae));
206 assert(0 == archive_write_finish_entry(a));
207 /* Create symlink to the file. */
208 archive_entry_copy_pathname(ae, "link_to_dir5");
209 archive_entry_set_mode(ae, S_IFLNK | 0777);
210 archive_entry_set_symlink(ae, "non_dir");
211 archive_write_disk_set_options(a, 0);
212 assert(0 == archive_write_header(a, ae));
213 assert(0 == archive_write_finish_entry(a));
214 /* Extract a dir whose name matches the symlink. */
215 assert(archive_entry_clear(ae) != NULL);
216 archive_entry_copy_pathname(ae, "link_to_dir5");
217 archive_entry_set_mode(ae, S_IFDIR | 0777);
218 assert(0 == archive_write_header(a, ae));
219 assert(0 == archive_write_finish_entry(a));
220 /* Verify link was replaced. */
221 assertEqualInt(0, lstat("link_to_dir5", &st));
222 assert(S_ISDIR(st.st_mode));
223 archive_entry_free(ae);
224
225 /*
226 * Without security checks, we should be able to
227 * extract an absolute path.
228 */
229 assert((ae = archive_entry_new()) != NULL);
230 archive_entry_copy_pathname(ae, "/tmp/libarchive_test-test_write_disk_secure-absolute_path.tmp");
231 archive_entry_set_mode(ae, S_IFREG | 0777);
232 assert(0 == archive_write_header(a, ae));
233 assert(0 == archive_write_finish_entry(a));
234 assertFileExists("/tmp/libarchive_test-test_write_disk_secure-absolute_path.tmp");
235 assert(0 == unlink("/tmp/libarchive_test-test_write_disk_secure-absolute_path.tmp"));
236
237 /* But with security checks enabled, this should fail. */
238 assert(archive_entry_clear(ae) != NULL);
239 archive_entry_copy_pathname(ae, "/tmp/libarchive_test-test_write_disk_secure-absolute_path.tmp");
240 archive_entry_set_mode(ae, S_IFREG | 0777);
241 archive_write_disk_set_options(a, ARCHIVE_EXTRACT_SECURE_NOABSOLUTEPATHS);
242 failure("Extracting an absolute path should fail here.");
243 assertEqualInt(ARCHIVE_FAILED, archive_write_header(a, ae));
244 archive_entry_free(ae);
245 assert(0 == archive_write_finish_entry(a));
246 assertFileNotExists("/tmp/libarchive_test-test_write_disk_secure-absolute_path.tmp");
247
248 assertEqualInt(ARCHIVE_OK, archive_write_free(a));
249
250 /* Test the entries on disk. */
251 assert(0 == lstat("dir", &st));
252 failure("dir: st.st_mode=%o", st.st_mode);
253 assert((st.st_mode & 0777) == 0755);
254
255 assert(0 == lstat("link_to_dir", &st));
256 failure("link_to_dir: st.st_mode=%o", st.st_mode);
257 assert(S_ISLNK(st.st_mode));
258 #if defined(HAVE_SYMLINK) && defined(HAVE_LCHMOD) && \
259 defined(S_IRUSR) && defined(S_IWUSR) && defined(S_IXUSR)
260 /* Verify if we are able to lchmod() */
261 if (symlink("dir", "testlink_to_dir") == 0) {
262 if (lchmod("testlink_to_dir",
263 S_IRUSR | S_IWUSR | S_IXUSR) != 0) {
264 switch (errno) {
265 case ENOTSUP:
266 case ENOSYS:
267 #if ENOTSUP != EOPNOTSUPP
268 case EOPNOTSUPP:
269 #endif
270 working_lchmod = 0;
271 break;
272 default:
273 working_lchmod = 1;
274 }
275 } else
276 working_lchmod = 1;
277 } else
278 working_lchmod = 0;
279
280 if (working_lchmod) {
281 failure("link_to_dir: st.st_mode=%o", st.st_mode);
282 assert((st.st_mode & 07777) == 0755);
283 }
284 #endif
285
286 assert(0 == lstat("dir/filea", &st));
287 failure("dir/filea: st.st_mode=%o", st.st_mode);
288 assert((st.st_mode & 07777) == 0755);
289
290 failure("dir/fileb: This file should not have been created");
291 assert(0 != lstat("dir/fileb", &st));
292
293 assert(0 == lstat("link_to_dir2", &st));
294 failure("link_to_dir2 should have been re-created as a true dir");
295 assert(S_ISDIR(st.st_mode));
296 failure("link_to_dir2: Implicit dir creation should obey umask, but st.st_mode=%o", st.st_mode);
297 assert((st.st_mode & 0777) == 0755);
298
299 assert(0 == lstat("link_to_dir2/filec", &st));
300 assert(S_ISREG(st.st_mode));
301 failure("link_to_dir2/filec: st.st_mode=%o", st.st_mode);
302 assert((st.st_mode & 07777) == 0755);
303
304 failure("dir/filed: This file should not have been created");
305 assert(0 != lstat("dir/filed", &st));
306 #endif
307 }
308