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/*-
* Copyright (c) 2011 Dag-Erling Smørgrav
* 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
* in this position and unchanged.
* 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 AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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.
*
* $Id: openpam_check_owner_perms.c 499 2011-11-22 11:51:50Z des $
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include <sys/types.h>
#include <sys/stat.h>
#include <errno.h>
#include <limits.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <security/pam_appl.h>
#include "openpam_impl.h"
/*
* OpenPAM internal
*
* Verify that the file or directory referenced by the given descriptor is
* owned by either root or the arbitrator and that it is not writable by
* group or other.
*/
int
openpam_check_desc_owner_perms(const char *name, int fd)
{
uid_t root, arbitrator;
struct stat sb;
int serrno;
root = 0;
arbitrator = geteuid();
if (fstat(fd, &sb) != 0) {
serrno = errno;
openpam_log(PAM_LOG_ERROR, "%s: %m", name);
errno = serrno;
return (-1);
}
if ((sb.st_uid != root && sb.st_uid != arbitrator) ||
(sb.st_mode & (S_IWGRP|S_IWOTH)) != 0) {
openpam_log(PAM_LOG_ERROR,
"%s: insecure ownership or permissions", name);
errno = EPERM;
return (-1);
}
return (0);
}
/*
* OpenPAM internal
*
* Verify that a file or directory and all components of the path leading
* up to it are owned by either root or the arbitrator and that they are
* not writable by group or other.
*
* Note that openpam_check_file_owner_perms() should be used instead if
* possible to avoid a race between the ownership / permission check and
* the actual open().
*/
int
openpam_check_path_owner_perms(const char *path)
{
uid_t root, arbitrator;
char pathbuf[PATH_MAX];
struct stat sb;
int len, serrno;
root = 0;
arbitrator = geteuid();
if (realpath(path, pathbuf) == NULL)
return (-1);
len = strlen(pathbuf);
while (len > 0) {
if (stat(pathbuf, &sb) != 0) {
serrno = errno;
openpam_log(PAM_LOG_ERROR, "%s: %m", pathbuf);
errno = serrno;
return (-1);
}
if ((sb.st_uid != root && sb.st_uid != arbitrator) ||
(sb.st_mode & (S_IWGRP|S_IWOTH)) != 0) {
openpam_log(PAM_LOG_ERROR,
"%s: insecure ownership or permissions", pathbuf);
errno = EPERM;
return (-1);
}
while (--len > 0 && pathbuf[len] != '/')
pathbuf[len] = '\0';
}
return (0);
}
/*
* NOPARSE
*/
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