freebsd-dev/lib/libpam/modules/pam_login_access/pam_login_access.c
Cy Schubert e8c4b9d46b This commit makes significant changes to pam_login_access(8) to bring it
up to par with the Linux pam_access(8).

Like the Linux pam_access(8) our pam_login_access(8) is a service module
for pam(3) that allows a administrator to limit access from specified
remote hosts or terminals. Unlike the Linux pam_access, pam_login_access
is missing some features which are added by this commit:

Access file can now be specified. The default remains /etc/access.conf.
The syntax is consistent with Linux pam_access.

By default usernames are matched. If the username fails to match a match
against a group name is attempted. The new nodefgroup module option will
only match a username and no attempt to match a group name is made.
Group names must be specified in brackets, "()" when nodefgroup is
specified. Otherwise the old backward compatible behavior is used.
This is consistent with Linux pam_access.

A new field separator module option allows the replacement of the default
colon (:) with any other character. This facilitates potential future
specification of X displays. This is also consistent with Linux pam_access.

A new list separator module option to replace the default space/comma/tab
with another character. This too is consistent with Linux pam_access.

Linux pam_access options not implemented in this commit are the debug
and audit options. These will be implemented at a later date.

Reviewed by:	bjk, bcr (for manpages)
Approved by:	des (blanket, implicit)
MFC after:	1 month
Differential Revision:	https://reviews.freebsd.org/D23198
2020-02-18 11:27:08 +00:00

132 lines
4.7 KiB
C

/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 2001 Mark R V Murray
* All rights reserved.
* Copyright (c) 2001 Networks Associates Technology, Inc.
* All rights reserved.
*
* Portions of this software were developed for the FreeBSD Project by
* ThinkSec AS and NAI Labs, the Security Research Division of Network
* Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035
* ("CBOSS"), as part of the DARPA CHATS research program.
*
* 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 author may not be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#define _BSD_SOURCE
#include <sys/param.h>
#include <sys/types.h>
#include <syslog.h>
#include <unistd.h>
#define PAM_SM_ACCOUNT
#include <security/pam_appl.h>
#include <security/pam_modules.h>
#include <security/pam_mod_misc.h>
#include <security/openpam.h>
#include "pam_login_access.h"
#define OPT_ACCESSFILE "accessfile"
#define OPT_NOAUDIT "noaudit"
#define OPT_FIELDSEP "fieldsep"
#define OPT_LISTSEP "listsep"
#define OPT_NODEFGROUP "nodefgroup"
#define _PATH_LOGACCESS "/etc/login.access"
#define _FIELD_SEPARATOR ":"
#define _LIST_SEPARATOR ", \t"
PAM_EXTERN int
pam_sm_acct_mgmt(pam_handle_t *pamh, int flags __unused,
int argc __unused, const char *argv[] __unused)
{
struct pam_login_access_options login_access_opts;
const void *rhost, *tty, *user;
char hostname[MAXHOSTNAMELEN];
int pam_err;
pam_err = pam_get_item(pamh, PAM_USER, &user);
if (pam_err != PAM_SUCCESS)
return (pam_err);
if (user == NULL)
return (PAM_SERVICE_ERR);
PAM_LOG("Got user: %s", (const char *)user);
pam_err = pam_get_item(pamh, PAM_RHOST, &rhost);
if (pam_err != PAM_SUCCESS)
return (pam_err);
pam_err = pam_get_item(pamh, PAM_TTY, &tty);
if (pam_err != PAM_SUCCESS)
return (pam_err);
gethostname(hostname, sizeof hostname);
login_access_opts.defgroup = openpam_get_option(pamh, OPT_NODEFGROUP) == NULL ? true : false;
login_access_opts.audit = openpam_get_option(pamh, OPT_NOAUDIT) == NULL ? true : false;
if ((login_access_opts.accessfile = openpam_get_option(pamh, OPT_ACCESSFILE)) == NULL)
login_access_opts.accessfile = _PATH_LOGACCESS;
if ((login_access_opts.fieldsep = openpam_get_option(pamh, OPT_FIELDSEP)) == NULL)
login_access_opts.fieldsep = _FIELD_SEPARATOR;
if ((login_access_opts.listsep = openpam_get_option(pamh, OPT_LISTSEP)) == NULL)
login_access_opts.listsep = _LIST_SEPARATOR;
if (rhost != NULL && *(const char *)rhost != '\0') {
PAM_LOG("Checking login.access for user %s from host %s",
(const char *)user, (const char *)rhost);
if (login_access(user, rhost, &login_access_opts) != 0)
return (PAM_SUCCESS);
PAM_VERBOSE_ERROR("%s is not allowed to log in from %s",
(const char *)user, (const char *)rhost);
} else if (tty != NULL && *(const char *)tty != '\0') {
PAM_LOG("Checking login.access for user %s on tty %s",
(const char *)user, (const char *)tty);
if (login_access(user, tty, &login_access_opts) != 0)
return (PAM_SUCCESS);
PAM_VERBOSE_ERROR("%s is not allowed to log in on %s",
(const char *)user, (const char *)tty);
} else {
PAM_LOG("Checking login.access for user %s",
(const char *)user);
if (login_access(user, "***unknown***", &login_access_opts) != 0)
return (PAM_SUCCESS);
PAM_VERBOSE_ERROR("%s is not allowed to log in",
(const char *)user);
}
return (PAM_AUTH_ERR);
}
PAM_MODULE_ENTRY("pam_login_access");