1/*-
2 * Copyright (c) 2011 Dag-Erling Sm��rgrav
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer
10 * in this position and unchanged.
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. The name of the author may not be used to endorse or promote
15 * products derived from this software without specific prior written
16 * permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 *
30 * $Id: openpam_check_owner_perms.c 543 2012-03-31 22:11:34Z des $
31 */
32
33#ifdef HAVE_CONFIG_H
34# include "config.h"
35#endif
36
37#include <sys/types.h>
38#include <sys/stat.h>

--- 26 unchanged lines hidden (view full) ---

65 root = 0;
66 arbitrator = geteuid();
67 if (fstat(fd, &sb) != 0) {
68 serrno = errno;
69 openpam_log(PAM_LOG_ERROR, "%s: %m", name);
70 errno = serrno;
71 return (-1);
72 }
73 if (!S_ISREG(sb.st_mode)) {
74 openpam_log(PAM_LOG_ERROR,
75 "%s: not a regular file", name);
76 errno = EINVAL;
77 return (-1);
78 }
79 if ((sb.st_uid != root && sb.st_uid != arbitrator) ||
80 (sb.st_mode & (S_IWGRP|S_IWOTH)) != 0) {
81 openpam_log(PAM_LOG_ERROR,
82 "%s: insecure ownership or permissions", name);
83 errno = EPERM;
84 return (-1);
85 }
86 return (0);
87}
88
89/*
90 * OpenPAM internal
91 *
92 * Verify that a file or directory and all components of the path leading
93 * up to it are owned by either root or the arbitrator and that they are
94 * not writable by group or other.
95 *
96 * Note that openpam_check_desc_owner_perms() should be used instead if
97 * possible to avoid a race between the ownership / permission check and
98 * the actual open().
99 */
100
101int
102openpam_check_path_owner_perms(const char *path)
103{
104 uid_t root, arbitrator;
105 char pathbuf[PATH_MAX];
106 struct stat sb;
107 int len, serrno, tip;
108
109 tip = 1;
110 root = 0;
111 arbitrator = geteuid();
112 if (realpath(path, pathbuf) == NULL)
113 return (-1);
114 len = strlen(pathbuf);
115 while (len > 0) {
116 if (stat(pathbuf, &sb) != 0) {
117 if (errno != ENOENT) {
118 serrno = errno;
119 openpam_log(PAM_LOG_ERROR, "%s: %m", pathbuf);
120 errno = serrno;
121 }
122 return (-1);
123 }
124 if (tip && !S_ISREG(sb.st_mode)) {
125 openpam_log(PAM_LOG_ERROR,
126 "%s: not a regular file", pathbuf);
127 errno = EINVAL;
128 return (-1);
129 }
130 if ((sb.st_uid != root && sb.st_uid != arbitrator) ||
131 (sb.st_mode & (S_IWGRP|S_IWOTH)) != 0) {
132 openpam_log(PAM_LOG_ERROR,
133 "%s: insecure ownership or permissions", pathbuf);
134 errno = EPERM;
135 return (-1);
136 }
137 while (--len > 0 && pathbuf[len] != '/')
138 pathbuf[len] = '\0';
139 tip = 0;
140 }
141 return (0);
142}
143
144/*
145 * NOPARSE
146 */