1/*	$NetBSD: pam_group.c,v 1.11 2009/02/11 18:38:56 christos Exp $	*/
2
3/*-
4 * Copyright (c) 2003 Networks Associates Technology, Inc.
5 * All rights reserved.
6 *
7 * Portions of this software were developed for the FreeBSD Project by
8 * ThinkSec AS and NAI Labs, the Security Research Division of Network
9 * Associates, Inc.  under DARPA/SPAWAR contract N66001-01-C-8035
10 * ("CBOSS"), as part of the DARPA CHATS research program.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 *    notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 *    notice, this list of conditions and the following disclaimer in the
19 *    documentation and/or other materials provided with the distribution.
20 * 3. The name of the author may not be used to endorse or promote
21 *    products derived from this software without specific prior written
22 *    permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 */
36
37#include <sys/cdefs.h>
38#ifdef __FreeBSD__
39__FBSDID("$FreeBSD: src/lib/libpam/modules/pam_group/pam_group.c,v 1.4 2003/12/11 13:55:15 des Exp $");
40#else
41__RCSID("$NetBSD: pam_group.c,v 1.11 2009/02/11 18:38:56 christos Exp $");
42#endif
43
44#include <sys/types.h>
45
46#include <grp.h>
47#include <pwd.h>
48#include <stdarg.h>
49#include <stdio.h>
50#include <string.h>
51#include <stdlib.h>
52#include <unistd.h>
53#include <login_cap.h>
54
55#define PAM_SM_AUTH
56
57#include <security/pam_appl.h>
58#include <security/pam_modules.h>
59#include <security/pam_mod_misc.h>
60#include <security/openpam.h>
61
62static int authenticate(pam_handle_t *, struct passwd *, int);
63
64#define PASSWORD_PROMPT         "%s's password:"
65
66PAM_EXTERN int
67pam_sm_authenticate(pam_handle_t *pamh, int flags __unused,
68    int argc __unused, const char *argv[] __unused)
69{
70	const char *group, *user;
71	const void *ruser;
72	char *const *list;
73	struct passwd *pwd, pwres;
74	struct group *grp, grres;
75	int pam_err, auth;
76	char *promptresp = NULL;
77	char pwbuf[1024];
78	char grbuf[1024];
79
80	/* get target account */
81	if (pam_get_user(pamh, &user, NULL) != PAM_SUCCESS ||
82	    user == NULL ||
83	    getpwnam_r(user, &pwres, pwbuf, sizeof(pwbuf), &pwd) != 0 ||
84	    pwd == NULL)
85		return (PAM_AUTH_ERR);
86	if (pwd->pw_uid != 0 && openpam_get_option(pamh, "root_only"))
87		return (PAM_IGNORE);
88
89	/* get applicant */
90	if (pam_get_item(pamh, PAM_RUSER, &ruser) != PAM_SUCCESS ||
91	    ruser == NULL ||
92	    getpwnam_r(ruser, &pwres, pwbuf, sizeof(pwbuf), &pwd) != 0 ||
93	    pwd == NULL)
94		return (PAM_AUTH_ERR);
95
96	auth = openpam_get_option(pamh, "authenticate") != NULL;
97
98	/* get regulating group */
99	if ((group = openpam_get_option(pamh, "group")) == NULL)
100		group = "wheel";
101	if (getgrnam_r(group, &grres, grbuf, sizeof(grbuf), &grp) != 0 ||
102	    grp == NULL || grp->gr_mem == NULL)
103		goto failed;
104
105	/* check if the group is empty */
106	if (*grp->gr_mem == NULL)
107		goto failed;
108
109	/* check membership */
110	if (pwd->pw_gid == grp->gr_gid)
111		goto found;
112	for (list = grp->gr_mem; *list != NULL; ++list)
113		if (strcmp(*list, pwd->pw_name) == 0)
114			goto found;
115
116 not_found:
117	if (openpam_get_option(pamh, "deny"))
118		return (PAM_SUCCESS);
119	if (!auth) {
120		pam_err = pam_prompt(pamh, PAM_ERROR_MSG, &promptresp,
121		    "%s: You are not listed in the correct secondary group"
122		    " (%s) to %s %s.", getprogname(), group, getprogname(),
123		    user);
124		if (pam_err == PAM_SUCCESS && promptresp)
125			free(promptresp);
126	}
127	return (PAM_AUTH_ERR);
128 found:
129	if (auth)
130		if ((pam_err = authenticate(pamh, pwd, flags)) != PAM_SUCCESS)
131			return pam_err;
132
133	if (openpam_get_option(pamh, "deny"))
134		return (PAM_AUTH_ERR);
135	return (PAM_SUCCESS);
136 failed:
137	if (openpam_get_option(pamh, "fail_safe"))
138		goto found;
139	else
140		goto not_found;
141}
142
143PAM_EXTERN int
144pam_sm_setcred(pam_handle_t * pamh __unused, int flags __unused,
145    int argc __unused, const char *argv[] __unused)
146{
147
148	return (PAM_SUCCESS);
149}
150
151static int
152authenticate(pam_handle_t *pamh, struct passwd *pwd, int flags)
153{
154	int retval;
155	login_cap_t *lc;
156	const char *pass;
157	char password_prompt[80];
158
159	(void) snprintf(password_prompt, sizeof(password_prompt),
160		    PASSWORD_PROMPT, pwd->pw_name);
161	lc = login_getpwclass(pwd);
162	retval = pam_get_authtok(pamh, PAM_AUTHTOK, &pass, password_prompt);
163	login_close(lc);
164
165	if (retval != PAM_SUCCESS)
166		return retval;
167        PAM_LOG("Got password");
168        if (strcmp(crypt(pass, pwd->pw_passwd), pwd->pw_passwd) == 0)
169                return PAM_SUCCESS;
170
171        PAM_VERBOSE_ERROR("UNIX authentication refused");
172        return PAM_AUTH_ERR;
173}
174
175
176PAM_MODULE_ENTRY("pam_group");
177