/*-

 * 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: head/lib/libarchive/test/test_write_disk_secure.c 201247 2009-12-30 05:59:21Z kientzle $");

#define UMASK 022

/*

 * Exercise security checks that should prevent certain

 * writes.

 */

DEFINE_TEST(test_write_disk_secure)

{

#if defined(_WIN32) && !defined(__CYGWIN__)

	skipping("archive_write_disk security checks not supported on Windows");

#else

	struct archive *a;

	struct archive_entry *ae;

	struct stat st;

	/* Start with a known umask. */

	assertUmask(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_FAILED, archive_write_header(a, ae));

	archive_entry_free(ae);

	assert(0 == archive_write_finish_entry(a));

	/* Write an absolute symlink to /tmp. */

	assert((ae = archive_entry_new()) != NULL);

	archive_entry_copy_pathname(ae, "/tmp/libarchive_test-test_write_disk_secure-absolute_symlink");

	archive_entry_set_mode(ae, S_IFLNK | 0777);

	archive_entry_set_symlink(ae, "/tmp");

	archive_write_disk_set_options(a, 0);

	assert(0 == archive_write_header(a, ae));

	assert(0 == archive_write_finish_entry(a));

	/* With security checks enabled, this should fail. */

	assert(archive_entry_clear(ae) != NULL);

	archive_entry_copy_pathname(ae, "/tmp/libarchive_test-test_write_disk_secure-absolute_symlink/libarchive_test-test_write_disk_secure-absolute_symlink_path.tmp");

	archive_entry_set_mode(ae, S_IFREG | 0777);

	archive_write_disk_set_options(a, ARCHIVE_EXTRACT_SECURE_SYMLINKS);

	failure("Extracting a file through an absolute symlink should fail here.");

	assertEqualInt(ARCHIVE_FAILED, archive_write_header(a, ae));

	archive_entry_free(ae);

	assertFileNotExists("/tmp/libarchive_test-test_write_disk_secure-absolute_symlink/libarchive_test-test_write_disk_secure-absolute_symlink_path.tmp");

	assert(0 == unlink("/tmp/libarchive_test-test_write_disk_secure-absolute_symlink"));

	unlink("/tmp/libarchive_test-test_write_disk_secure-absolute_symlink_path.tmp");

	/* 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));

	/* Create a nested symlink. */

	assert((ae = archive_entry_new()) != NULL);

	archive_entry_copy_pathname(ae, "dir/nested_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));

	/* But with security checks enabled, this should fail. */

	assert(archive_entry_clear(ae) != NULL);

	archive_entry_copy_pathname(ae, "dir/nested_link_to_dir/filed");

	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_FAILED, 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 replaced. */

	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 replaced. */

	assertEqualInt(0, lstat("link_to_dir5", &st);;

	assert(S_ISDIR(st.st_mode));

	archive_entry_free(ae);

	/*

	 * Without security checks, we should be able to

	 * extract an absolute path.

	 */

	assert((ae = archive_entry_new()) != NULL);

	archive_entry_copy_pathname(ae, "/tmp/libarchive_test-test_write_disk_secure-absolute_path.tmp");

	archive_entry_set_mode(ae, S_IFREG | 0777);

	assert(0 == archive_write_header(a, ae));

	assert(0 == archive_write_finish_entry(a));

	assertFileExists("/tmp/libarchive_test-test_write_disk_secure-absolute_path.tmp");

	assert(0 == unlink("/tmp/libarchive_test-test_write_disk_secure-absolute_path.tmp"));

	/* But with security checks enabled, this should fail. */

	assert(archive_entry_clear(ae) != NULL);

	archive_entry_copy_pathname(ae, "/tmp/libarchive_test-test_write_disk_secure-absolute_path.tmp");

	archive_entry_set_mode(ae, S_IFREG | 0777);

	archive_write_disk_set_options(a, ARCHIVE_EXTRACT_SECURE_NOABSOLUTEPATHS);

	failure("Extracting an absolute path should fail here.");

	assertEqualInt(ARCHIVE_FAILED, archive_write_header(a, ae));

	archive_entry_free(ae);

	assert(0 == archive_write_finish_entry(a));

	assertFileNotExists("/tmp/libarchive_test-test_write_disk_secure-absolute_path.tmp");

	assertEqualInt(ARCHIVE_OK, archive_write_free(a));

	/* 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);

	failure("dir/filed: This file should not have been created");

	assert(0 != lstat("dir/filed", &st);;

#endif

}