1/*	$NetBSD: secure_path.c,v 1.1 2001/08/20 14:47:50 wiz Exp $	*/
2
3/*-
4 * Copyright (c) 1995,1997 Berkeley Software Design, Inc. All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 * 3. All advertising materials mentioning features or use of this software
15 *    must display the following acknowledgement:
16 *	This product includes software developed by Berkeley Software Design,
17 *	Inc.
18 * 4. The name of Berkeley Software Design, Inc.  may not be used to endorse
19 *    or promote products derived from this software without specific prior
20 *    written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN, INC. ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED.  IN NO EVENT SHALL BERKELEY SOFTWARE DESIGN, INC. BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
34 *	BSDI login_cap.c,v 2.13 1998/02/07 03:17:05 prb Exp
35 */
36
37#include <sys/cdefs.h>
38#if defined(LIBC_SCCS) && !defined(lint)
39__RCSID("$NetBSD: secure_path.c,v 1.1 2001/08/20 14:47:50 wiz Exp $");
40#endif /* LIBC_SCCS and not lint */
41
42#include <sys/types.h>
43#include <sys/stat.h>
44
45#include <assert.h>
46#include <syslog.h>
47#include <util.h>
48
49int
50secure_path(const char *path)
51{
52	struct stat sb;
53
54	_DIAGASSERT(path != NULL);
55
56	/*
57	 * If not a regular file, or is owned/writable by someone
58	 * other than root, quit.
59	 */
60	if (lstat(path, &sb) < 0)
61		/* syslog(LOG_ERR, "cannot stat %s: %m", path) */;
62	else if (!S_ISREG(sb.st_mode))
63		syslog(LOG_ERR, "%s: not a regular file", path);
64	else if (sb.st_uid != 0)
65		syslog(LOG_ERR, "%s: not owned by root", path);
66	else if ((sb.st_mode & (S_IWGRP | S_IWOTH)) != 0)
67		syslog(LOG_ERR, "%s: writable by non-root", path);
68	else
69		return (0);
70
71	return (-1);
72}
73