1 /*	$NetBSD: safefile.c,v 1.4 2006/09/09 16:22:10 manu Exp $	*/
2 
3 /*	$KAME: safefile.c,v 1.5 2001/03/05 19:54:06 thorpej Exp $	*/
4 
5 /*
6  * Copyright (C) 2000 WIDE Project.
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. Neither the name of the project nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #include "config.h"
35 
36 #include <sys/types.h>
37 #include <sys/stat.h>
38 #include <sys/socket.h>
39 #include <netinet/in.h>
40 #include <unistd.h>
41 
42 #include "plog.h"
43 #include "debug.h"
44 #include "misc.h"
45 #include "safefile.h"
46 
47 int
safefile(path,secret)48 safefile(path, secret)
49 	const char *path;
50 	int secret;
51 {
52 	struct stat s;
53 	uid_t me;
54 
55 	/* no setuid */
56 	if (getuid() != geteuid()) {
57 		plog(LLV_ERROR, LOCATION, NULL,
58 		    "setuid'ed execution not allowed\n");
59 		return -1;
60 	}
61 
62 	if (stat(path, &s) != 0)
63 		return -1;
64 
65 	/* the file must be owned by the running uid */
66 	me = getuid();
67 	if (s.st_uid != me) {
68 		plog(LLV_ERROR, LOCATION, NULL,
69 		    "%s has invalid owner uid\n", path);
70 		return -1;
71 	}
72 
73 	switch (s.st_mode & S_IFMT) {
74 	case S_IFREG:
75 		break;
76 	default:
77 		plog(LLV_ERROR, LOCATION, NULL,
78 		    "%s is an invalid file type 0x%x\n", path,
79 		    (s.st_mode & S_IFMT));
80 		return -1;
81 	}
82 
83 	/* secret file should not be read by others */
84 	if (secret) {
85 		if ((s.st_mode & S_IRWXG) != 0 || (s.st_mode & S_IRWXO) != 0) {
86 			plog(LLV_ERROR, LOCATION, NULL,
87 			    "%s has weak file permission\n", path);
88 			return -1;
89 		}
90 	}
91 
92 	return 0;
93 }
94