shadow/libmisc/setugid.c
2010-08-22 13:04:54 +00:00

149 lines
4.2 KiB
C

/*
* Copyright (c) 1989 - 1994, Julianne Frances Haugh
* Copyright (c) 1996 - 1998, Marek Michałkiewicz
* Copyright (c) 2003 - 2005, Tomasz Kłoczko
* Copyright (c) 2008 - 2010, Nicolas François
* 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.
* 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.
* 3. The name of the copyright holders or contributors may not be used to
* endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT
* HOLDERS 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.
*/
/*
* Separated from setup.c. --marekm
*/
#include <config.h>
#ident "$Id$"
#include <stdio.h>
#include <grp.h>
#include <errno.h>
#include "prototypes.h"
#include "defines.h"
#include <pwd.h>
#include "getdef.h"
/*
* setup_groups - set the group credentials
* set the group ID to the value from the password file entry
* set the supplementary group IDs
*
* In case of PAM enabled configurations, this shall be called before
* pam_setcred.
*
* Returns 0 on success, or -1 on failure.
*/
int setup_groups (const struct passwd *info)
{
/*
* Set the real group ID to the primary group ID in the password
* file.
*/
if (setgid (info->pw_gid) == -1) {
int err = errno;
perror ("setgid");
SYSLOG ((LOG_ERR, "bad group ID `%d' for user `%s': %s\n",
info->pw_gid, info->pw_name, strerror (err)));
closelog ();
return -1;
}
#ifdef HAVE_INITGROUPS
/*
* For systems which support multiple concurrent groups, go get
* the group set from the /etc/group file.
*/
if (initgroups (info->pw_name, info->pw_gid) == -1) {
int err = errno;
perror ("initgroups");
SYSLOG ((LOG_ERR, "initgroups failed for user `%s': %s\n",
info->pw_name, strerror (err)));
closelog ();
return -1;
}
#endif
return 0;
}
/*
* change_uid - Set the real UID
*
* Returns 0 on success, or -1 on failure.
*/
int change_uid (const struct passwd *info)
{
/*
* Set the real UID to the UID value in the password file.
*/
if (setuid (info->pw_uid) != 0) {
int err = errno;
perror ("setuid");
SYSLOG ((LOG_ERR, "bad user ID `%d' for user `%s': %s\n",
(int) info->pw_uid, info->pw_name, strerror (err)));
closelog ();
return -1;
}
return 0;
}
/*
* setup_uid_gid() performs the following steps -
*
* set the group ID to the value from the password file entry
* set the supplementary group IDs
* optionally call specified function which may add more groups
* set the user ID to the value from the password file entry
*
* Returns 0 on success, or -1 on failure.
*/
#if defined (HAVE_INITGROUPS) && ! (defined USE_PAM)
int setup_uid_gid (const struct passwd *info, bool is_console)
#else
int setup_uid_gid (const struct passwd *info)
#endif
{
if (setup_groups (info) < 0) {
return -1;
}
#if defined (HAVE_INITGROUPS) && ! defined (USE_PAM)
if (is_console) {
const char *cp = getdef_str ("CONSOLE_GROUPS");
if ((NULL != cp) && (add_groups (cp) != 0)) {
perror ("Warning: add_groups");
}
}
#endif /* HAVE_INITGROUPS && !USE_PAM*/
if (change_uid (info) < 0) {
return -1;
}
return 0;
}