lib/libutil/secure_path.c

   1 /*      $NetBSD: secure_path.c,v 1.2 2003/01/06 20:30:30 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 1.2 2003/01/06 20:30:30 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
  49 int
  50 secure_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 }