1/*-
2 * Copyright 1998 Juniper Networks, Inc.
3 * All rights reserved.
4 * Copyright (c) 2001-2003 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__FBSDID("$FreeBSD$");
39
40#include <sys/param.h>
41
42#include <pwd.h>
43#include <stdlib.h>
44#include <string.h>
45#include <syslog.h>
46#include <taclib.h>
47#include <unistd.h>
48
49#define PAM_SM_AUTH
50
51#include <security/pam_appl.h>
52#include <security/pam_modules.h>
53#include <security/pam_mod_misc.h>
54
55#define PAM_OPT_CONF		"conf"
56#define PAM_OPT_TEMPLATE_USER	"template_user"
57
58typedef int (*set_func)(struct tac_handle *, const char *);
59
60static int	 do_item(pam_handle_t *, struct tac_handle *, int,
61		    set_func, const char *);
62static char	*get_msg(struct tac_handle *);
63static int	 set_msg(struct tac_handle *, const char *);
64
65static int
66do_item(pam_handle_t *pamh, struct tac_handle *tach, int item,
67    set_func func, const char *funcname)
68{
69	int retval;
70	const void *value;
71
72	retval = pam_get_item(pamh, item, &value);
73	if (retval != PAM_SUCCESS)
74	    return retval;
75	if (value != NULL && (*func)(tach, (const char *)value) == -1) {
76		syslog(LOG_CRIT, "%s: %s", funcname, tac_strerror(tach));
77		tac_close(tach);
78		return PAM_SERVICE_ERR;
79	}
80	return PAM_SUCCESS;
81}
82
83static char *
84get_msg(struct tac_handle *tach)
85{
86	char *msg;
87
88	msg = tac_get_msg(tach);
89	if (msg == NULL) {
90		syslog(LOG_CRIT, "tac_get_msg: %s", tac_strerror(tach));
91		tac_close(tach);
92		return NULL;
93	}
94	return msg;
95}
96
97static int
98set_msg(struct tac_handle *tach, const char *msg)
99{
100	if (tac_set_msg(tach, msg) == -1) {
101		syslog(LOG_CRIT, "tac_set_msg: %s", tac_strerror(tach));
102		tac_close(tach);
103		return -1;
104	}
105	return 0;
106}
107
108PAM_EXTERN int
109pam_sm_authenticate(pam_handle_t *pamh, int flags __unused,
110    int argc __unused, const char *argv[] __unused)
111{
112	int retval;
113	struct tac_handle *tach;
114	const char *conf_file, *template_user;
115
116	conf_file = openpam_get_option(pamh, PAM_OPT_CONF);
117	template_user = openpam_get_option(pamh, PAM_OPT_TEMPLATE_USER);
118
119	tach = tac_open();
120	if (tach == NULL) {
121		syslog(LOG_CRIT, "tac_open failed");
122		return (PAM_SERVICE_ERR);
123	}
124	if (tac_config(tach, conf_file) == -1) {
125		syslog(LOG_ALERT, "tac_config: %s", tac_strerror(tach));
126		tac_close(tach);
127		return (PAM_SERVICE_ERR);
128	}
129	if (tac_create_authen(tach, TAC_AUTHEN_LOGIN, TAC_AUTHEN_TYPE_ASCII,
130	    TAC_AUTHEN_SVC_LOGIN) == -1) {
131		syslog(LOG_CRIT, "tac_create_authen: %s", tac_strerror(tach));
132		tac_close(tach);
133		return (PAM_SERVICE_ERR);
134	}
135
136	PAM_LOG("Done tac_open() ... tac_close()");
137
138	retval = do_item(pamh, tach, PAM_USER, tac_set_user, "tac_set_user");
139	if (retval != PAM_SUCCESS)
140		return (retval);
141
142	PAM_LOG("Done user");
143
144	retval = do_item(pamh, tach, PAM_TTY, tac_set_port, "tac_set_port");
145	if (retval != PAM_SUCCESS)
146		return (retval);
147
148	PAM_LOG("Done tty");
149
150	retval = do_item(pamh, tach, PAM_RHOST, tac_set_rem_addr,
151	    "tac_set_rem_addr");
152	if (retval != PAM_SUCCESS)
153		return (retval);
154
155	for (;;) {
156		char *srvr_msg;
157		size_t msg_len;
158		const char *user_msg;
159		char *data_msg;
160		int sflags;
161		int status;
162
163		sflags = tac_send_authen(tach);
164		if (sflags == -1) {
165			syslog(LOG_CRIT, "tac_send_authen: %s",
166			    tac_strerror(tach));
167			tac_close(tach);
168			return (PAM_AUTHINFO_UNAVAIL);
169		}
170		status = TAC_AUTHEN_STATUS(sflags);
171		openpam_set_option(pamh, PAM_OPT_ECHO_PASS,
172		    TAC_AUTHEN_NOECHO(sflags) ? NULL : "");
173		switch (status) {
174
175		case TAC_AUTHEN_STATUS_PASS:
176			tac_close(tach);
177			if (template_user != NULL) {
178				const void *item;
179				const char *user;
180
181				PAM_LOG("Trying template user: %s",
182				    template_user);
183
184				/*
185				 * If the given user name doesn't exist in
186				 * the local password database, change it
187				 * to the value given in the "template_user"
188				 * option.
189				 */
190				retval = pam_get_item(pamh, PAM_USER, &item);
191				if (retval != PAM_SUCCESS)
192					return (retval);
193				user = (const char *)item;
194				if (getpwnam(user) == NULL) {
195					pam_set_item(pamh, PAM_USER,
196					    template_user);
197					PAM_LOG("Using template user");
198				}
199			}
200			return (PAM_SUCCESS);
201
202		case TAC_AUTHEN_STATUS_FAIL:
203			tac_close(tach);
204			PAM_VERBOSE_ERROR("TACACS+ authentication failed");
205			return (PAM_AUTH_ERR);
206
207		case TAC_AUTHEN_STATUS_GETUSER:
208		case TAC_AUTHEN_STATUS_GETPASS:
209			if ((srvr_msg = get_msg(tach)) == NULL)
210				return (PAM_SERVICE_ERR);
211			if (status == TAC_AUTHEN_STATUS_GETUSER)
212				retval = pam_get_user(pamh, &user_msg,
213				    *srvr_msg ? srvr_msg : NULL);
214			else if (status == TAC_AUTHEN_STATUS_GETPASS)
215				retval = pam_get_authtok(pamh,
216				    PAM_AUTHTOK, &user_msg,
217				    *srvr_msg ? srvr_msg : "Password:");
218			free(srvr_msg);
219			if (retval != PAM_SUCCESS) {
220				/* XXX - send a TACACS+ abort packet */
221				tac_close(tach);
222				return (retval);
223			}
224			if (set_msg(tach, user_msg) == -1)
225				return (PAM_SERVICE_ERR);
226			break;
227
228		case TAC_AUTHEN_STATUS_GETDATA:
229			if ((srvr_msg = get_msg(tach)) == NULL)
230				return (PAM_SERVICE_ERR);
231			retval = pam_prompt(pamh,
232			    openpam_get_option(pamh, PAM_OPT_ECHO_PASS) ?
233			    PAM_PROMPT_ECHO_ON : PAM_PROMPT_ECHO_OFF,
234			    &data_msg, "%s", *srvr_msg ? srvr_msg : "Data:");
235			free(srvr_msg);
236			if (retval != PAM_SUCCESS) {
237				/* XXX - send a TACACS+ abort packet */
238				tac_close(tach);
239				return (retval);
240			}
241			retval = set_msg(tach, data_msg);
242			memset(data_msg, 0, strlen(data_msg));
243			free(data_msg);
244			if (retval == -1)
245				return (PAM_SERVICE_ERR);
246			break;
247
248		case TAC_AUTHEN_STATUS_ERROR:
249			srvr_msg = (char *)tac_get_data(tach, &msg_len);
250			if (srvr_msg != NULL && msg_len != 0) {
251				syslog(LOG_CRIT, "tac_send_authen:"
252				    " server detected error: %s", srvr_msg);
253				free(srvr_msg);
254			}
255			else
256				syslog(LOG_CRIT,
257				    "tac_send_authen: server detected error");
258			tac_close(tach);
259			return (PAM_AUTHINFO_UNAVAIL);
260			break;
261
262		case TAC_AUTHEN_STATUS_RESTART:
263		case TAC_AUTHEN_STATUS_FOLLOW:
264		default:
265			syslog(LOG_CRIT,
266			    "tac_send_authen: unexpected status %#x", status);
267			tac_close(tach);
268			return (PAM_AUTHINFO_UNAVAIL);
269		}
270	}
271}
272
273PAM_EXTERN int
274pam_sm_setcred(pam_handle_t *pamh __unused, int flags __unused,
275    int argc __unused, const char *argv[] __unused)
276{
277
278	return (PAM_IGNORE);
279}
280
281PAM_MODULE_ENTRY("pam_tacplus");
282