freebsd-nq/lib/libarchive/test/test_write_disk_secure.c
Tim Kientzle 11663004bd When restoring a directory, allow symlinks to be followed. The full
logic here gets a little complex, but the net effect is that the
SECURE_SYMLINKS flag will prevent us from ever following a symlink.
Without it, we'll only follow symlinks to dirs.  bsdtar specifies
SECURE_SYMLINKS by default, suppresses it for -P.

I've also beefed up the write_disk_secure test to verify this
behavior.

PR:		bin/126849
2008-09-07 05:22:33 +00:00

220 lines
7.9 KiB
C

/*-
* Copyright (c) 2003-2007 Tim Kientzle
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "test.h"
__FBSDID("$FreeBSD$");
#define UMASK 022
/*
* Exercise security checks that should prevent certain
* writes.
*/
DEFINE_TEST(test_write_disk_secure)
{
#if ARCHIVE_VERSION_NUMBER < 1009000
skipping("archive_write_disk interface");
#else
struct archive *a;
struct archive_entry *ae;
struct stat st;
/* Start with a known umask. */
umask(UMASK);
/* Create an archive_write_disk object. */
assert((a = archive_write_disk_new()) != NULL);
/* Write a regular dir to it. */
assert((ae = archive_entry_new()) != NULL);
archive_entry_copy_pathname(ae, "dir");
archive_entry_set_mode(ae, S_IFDIR | 0777);
assert(0 == archive_write_header(a, ae));
archive_entry_free(ae);
assert(0 == archive_write_finish_entry(a));
/* Write a symlink to the dir above. */
assert((ae = archive_entry_new()) != NULL);
archive_entry_copy_pathname(ae, "link_to_dir");
archive_entry_set_mode(ae, S_IFLNK | 0777);
archive_entry_set_symlink(ae, "dir");
archive_write_disk_set_options(a, 0);
assert(0 == archive_write_header(a, ae));
assert(0 == archive_write_finish_entry(a));
/*
* Without security checks, we should be able to
* extract a file through the link.
*/
assert(archive_entry_clear(ae) != NULL);
archive_entry_copy_pathname(ae, "link_to_dir/filea");
archive_entry_set_mode(ae, S_IFREG | 0777);
assert(0 == archive_write_header(a, ae));
assert(0 == archive_write_finish_entry(a));
/* But with security checks enabled, this should fail. */
assert(archive_entry_clear(ae) != NULL);
archive_entry_copy_pathname(ae, "link_to_dir/fileb");
archive_entry_set_mode(ae, S_IFREG | 0777);
archive_write_disk_set_options(a, ARCHIVE_EXTRACT_SECURE_SYMLINKS);
failure("Extracting a file through a symlink should fail here.");
assertEqualInt(ARCHIVE_WARN, archive_write_header(a, ae));
archive_entry_free(ae);
assert(0 == archive_write_finish_entry(a));
/* Create another link. */
assert((ae = archive_entry_new()) != NULL);
archive_entry_copy_pathname(ae, "link_to_dir2");
archive_entry_set_mode(ae, S_IFLNK | 0777);
archive_entry_set_symlink(ae, "dir");
archive_write_disk_set_options(a, 0);
assert(0 == archive_write_header(a, ae));
assert(0 == archive_write_finish_entry(a));
/*
* With symlink check and unlink option, it should remove
* the link and create the dir.
*/
assert(archive_entry_clear(ae) != NULL);
archive_entry_copy_pathname(ae, "link_to_dir2/filec");
archive_entry_set_mode(ae, S_IFREG | 0777);
archive_write_disk_set_options(a, ARCHIVE_EXTRACT_SECURE_SYMLINKS | ARCHIVE_EXTRACT_UNLINK);
assertEqualIntA(a, ARCHIVE_OK, archive_write_header(a, ae));
archive_entry_free(ae);
assert(0 == archive_write_finish_entry(a));
/*
* Without security checks, extracting a dir over a link to a
* dir should follow the link.
*/
/* Create a symlink to a dir. */
assert((ae = archive_entry_new()) != NULL);
archive_entry_copy_pathname(ae, "link_to_dir3");
archive_entry_set_mode(ae, S_IFLNK | 0777);
archive_entry_set_symlink(ae, "dir");
archive_write_disk_set_options(a, 0);
assert(0 == archive_write_header(a, ae));
assert(0 == archive_write_finish_entry(a));
/* Extract a dir whose name matches the symlink. */
assert(archive_entry_clear(ae) != NULL);
archive_entry_copy_pathname(ae, "link_to_dir3");
archive_entry_set_mode(ae, S_IFDIR | 0777);
assert(0 == archive_write_header(a, ae));
assert(0 == archive_write_finish_entry(a));
/* Verify link was followed. */
assertEqualInt(0, lstat("link_to_dir3", &st));
assert(S_ISLNK(st.st_mode));
archive_entry_free(ae);
/*
* As above, but a broken link, so the link should get replaced.
*/
/* Create a symlink to a dir. */
assert((ae = archive_entry_new()) != NULL);
archive_entry_copy_pathname(ae, "link_to_dir4");
archive_entry_set_mode(ae, S_IFLNK | 0777);
archive_entry_set_symlink(ae, "nonexistent_dir");
archive_write_disk_set_options(a, 0);
assert(0 == archive_write_header(a, ae));
assert(0 == archive_write_finish_entry(a));
/* Extract a dir whose name matches the symlink. */
assert(archive_entry_clear(ae) != NULL);
archive_entry_copy_pathname(ae, "link_to_dir4");
archive_entry_set_mode(ae, S_IFDIR | 0777);
assert(0 == archive_write_header(a, ae));
assert(0 == archive_write_finish_entry(a));
/* Verify link was followed. */
assertEqualInt(0, lstat("link_to_dir4", &st));
assert(S_ISDIR(st.st_mode));
archive_entry_free(ae);
/*
* As above, but a link to a non-dir, so the link should get replaced.
*/
/* Create a regular file and a symlink to it */
assert((ae = archive_entry_new()) != NULL);
archive_entry_copy_pathname(ae, "non_dir");
archive_entry_set_mode(ae, S_IFREG | 0777);
archive_write_disk_set_options(a, 0);
assert(0 == archive_write_header(a, ae));
assert(0 == archive_write_finish_entry(a));
/* Create symlink to the file. */
archive_entry_copy_pathname(ae, "link_to_dir5");
archive_entry_set_mode(ae, S_IFLNK | 0777);
archive_entry_set_symlink(ae, "non_dir");
archive_write_disk_set_options(a, 0);
assert(0 == archive_write_header(a, ae));
assert(0 == archive_write_finish_entry(a));
/* Extract a dir whose name matches the symlink. */
assert(archive_entry_clear(ae) != NULL);
archive_entry_copy_pathname(ae, "link_to_dir5");
archive_entry_set_mode(ae, S_IFDIR | 0777);
assert(0 == archive_write_header(a, ae));
assert(0 == archive_write_finish_entry(a));
/* Verify link was followed. */
assertEqualInt(0, lstat("link_to_dir5", &st));
assert(S_ISDIR(st.st_mode));
#if ARCHIVE_VERSION_NUMBER < 2000000
archive_write_finish(a);
#else
assert(0 == archive_write_finish(a));
#endif
/* Test the entries on disk. */
assert(0 == lstat("dir", &st));
failure("dir: st.st_mode=%o", st.st_mode);
assert((st.st_mode & 0777) == 0755);
assert(0 == lstat("link_to_dir", &st));
failure("link_to_dir: st.st_mode=%o", st.st_mode);
assert(S_ISLNK(st.st_mode));
#if HAVE_LCHMOD
/* Systems that lack lchmod() can't set symlink perms, so skip this. */
failure("link_to_dir: st.st_mode=%o", st.st_mode);
assert((st.st_mode & 07777) == 0755);
#endif
assert(0 == lstat("dir/filea", &st));
failure("dir/filea: st.st_mode=%o", st.st_mode);
assert((st.st_mode & 07777) == 0755);
failure("dir/fileb: This file should not have been created");
assert(0 != lstat("dir/fileb", &st));
assert(0 == lstat("link_to_dir2", &st));
failure("link_to_dir2 should have been re-created as a true dir");
assert(S_ISDIR(st.st_mode));
failure("link_to_dir2: Implicit dir creation should obey umask, but st.st_mode=%o", st.st_mode);
assert((st.st_mode & 0777) == 0755);
assert(0 == lstat("link_to_dir2/filec", &st));
assert(S_ISREG(st.st_mode));
failure("link_to_dir2/filec: st.st_mode=%o", st.st_mode);
assert((st.st_mode & 07777) == 0755);
#endif
}