openpam_dispatch.c revision 294192
1/*-
2 * Copyright (c) 2002-2003 Networks Associates Technology, Inc.
3 * Copyright (c) 2004-2011 Dag-Erling Sm��rgrav
4 * All rights reserved.
5 *
6 * This software was developed for the FreeBSD Project by ThinkSec AS and
7 * Network Associates Laboratories, the Security Research Division of
8 * Network Associates, Inc.  under DARPA/SPAWAR contract N66001-01-C-8035
9 * ("CBOSS"), as part of the DARPA CHATS research program.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 *    notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 *    notice, this list of conditions and the following disclaimer in the
18 *    documentation and/or other materials provided with the distribution.
19 * 3. The name of the author may not be used to endorse or promote
20 *    products derived from this software without specific prior written
21 *    permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 *
35 * $Id: openpam_dispatch.c 807 2014-09-09 09:41:32Z des $
36 */
37
38#ifdef HAVE_CONFIG_H
39# include "config.h"
40#endif
41
42#include <sys/param.h>
43
44#include <security/pam_appl.h>
45
46#include "openpam_impl.h"
47
48#if !defined(OPENPAM_RELAX_CHECKS)
49static void openpam_check_error_code(int, int);
50#else
51#define openpam_check_error_code(a, b)
52#endif /* !defined(OPENPAM_RELAX_CHECKS) */
53
54/*
55 * OpenPAM internal
56 *
57 * Execute a module chain
58 */
59
60int
61openpam_dispatch(pam_handle_t *pamh,
62	int primitive,
63	int flags)
64{
65	pam_chain_t *chain;
66	int err, fail, nsuccess, r;
67	int debug;
68
69	ENTER();
70	if (pamh == NULL)
71		RETURNC(PAM_SYSTEM_ERR);
72
73	/* prevent recursion */
74	if (pamh->current != NULL) {
75		openpam_log(PAM_LOG_ERROR,
76		    "%s() called while %s::%s() is in progress",
77		    pam_func_name[primitive],
78		    pamh->current->module->path,
79		    pam_sm_func_name[pamh->primitive]);
80		RETURNC(PAM_ABORT);
81	}
82
83	/* pick a chain */
84	switch (primitive) {
85	case PAM_SM_AUTHENTICATE:
86	case PAM_SM_SETCRED:
87		chain = pamh->chains[PAM_AUTH];
88		break;
89	case PAM_SM_ACCT_MGMT:
90		chain = pamh->chains[PAM_ACCOUNT];
91		break;
92	case PAM_SM_OPEN_SESSION:
93	case PAM_SM_CLOSE_SESSION:
94		chain = pamh->chains[PAM_SESSION];
95		break;
96	case PAM_SM_CHAUTHTOK:
97		chain = pamh->chains[PAM_PASSWORD];
98		break;
99	default:
100		RETURNC(PAM_SYSTEM_ERR);
101	}
102
103	/* execute */
104	err = PAM_SUCCESS;
105	fail = nsuccess = 0;
106	for (; chain != NULL; chain = chain->next) {
107		if (chain->module->func[primitive] == NULL) {
108			openpam_log(PAM_LOG_ERROR, "%s: no %s()",
109			    chain->module->path, pam_sm_func_name[primitive]);
110			r = PAM_SYSTEM_ERR;
111		} else {
112			pamh->primitive = primitive;
113			pamh->current = chain;
114			debug = (openpam_get_option(pamh, "debug") != NULL);
115			if (debug)
116				++openpam_debug;
117			openpam_log(PAM_LOG_LIBDEBUG, "calling %s() in %s",
118			    pam_sm_func_name[primitive], chain->module->path);
119			r = (chain->module->func[primitive])(pamh, flags,
120			    chain->optc, (const char **)(intptr_t)chain->optv);
121			pamh->current = NULL;
122			openpam_log(PAM_LOG_LIBDEBUG, "%s: %s(): %s",
123			    chain->module->path, pam_sm_func_name[primitive],
124			    pam_strerror(pamh, r));
125			if (debug)
126				--openpam_debug;
127		}
128
129		if (r == PAM_IGNORE)
130			continue;
131		if (r == PAM_SUCCESS) {
132			++nsuccess;
133			/*
134			 * For pam_setcred() and pam_chauthtok() with the
135			 * PAM_PRELIM_CHECK flag, treat "sufficient" as
136			 * "optional".
137			 */
138			if ((chain->flag == PAM_SUFFICIENT ||
139			    chain->flag == PAM_BINDING) && !fail &&
140			    primitive != PAM_SM_SETCRED &&
141			    !(primitive == PAM_SM_CHAUTHTOK &&
142				(flags & PAM_PRELIM_CHECK)))
143				break;
144			continue;
145		}
146
147		openpam_check_error_code(primitive, r);
148
149		/*
150		 * Record the return code from the first module to
151		 * fail.  If a required module fails, record the
152		 * return code from the first required module to fail.
153		 */
154		if (err == PAM_SUCCESS)
155			err = r;
156		if ((chain->flag == PAM_REQUIRED ||
157		    chain->flag == PAM_BINDING) && !fail) {
158			openpam_log(PAM_LOG_LIBDEBUG, "required module failed");
159			fail = 1;
160			err = r;
161		}
162
163		/*
164		 * If a requisite module fails, terminate the chain
165		 * immediately.
166		 */
167		if (chain->flag == PAM_REQUISITE) {
168			openpam_log(PAM_LOG_LIBDEBUG, "requisite module failed");
169			fail = 1;
170			break;
171		}
172	}
173
174	if (!fail && err != PAM_NEW_AUTHTOK_REQD)
175		err = PAM_SUCCESS;
176
177	/*
178	 * Require the chain to be non-empty, and at least one module
179	 * in the chain to be successful, so that we don't fail open.
180	 */
181	if (err == PAM_SUCCESS && nsuccess < 1) {
182		openpam_log(PAM_LOG_ERROR,
183		    "all modules were unsuccessful for %s()",
184		    pam_sm_func_name[primitive]);
185		err = PAM_SYSTEM_ERR;
186	}
187
188	RETURNC(err);
189}
190
191#if !defined(OPENPAM_RELAX_CHECKS)
192static void
193openpam_check_error_code(int primitive, int r)
194{
195	/* common error codes */
196	if (r == PAM_SUCCESS ||
197	    r == PAM_SYSTEM_ERR ||
198	    r == PAM_SERVICE_ERR ||
199	    r == PAM_BUF_ERR ||
200	    r == PAM_CONV_ERR ||
201	    r == PAM_PERM_DENIED ||
202	    r == PAM_ABORT)
203		return;
204
205	/* specific error codes */
206	switch (primitive) {
207	case PAM_SM_AUTHENTICATE:
208		if (r == PAM_AUTH_ERR ||
209		    r == PAM_CRED_INSUFFICIENT ||
210		    r == PAM_AUTHINFO_UNAVAIL ||
211		    r == PAM_USER_UNKNOWN ||
212		    r == PAM_MAXTRIES)
213			return;
214		break;
215	case PAM_SM_SETCRED:
216		if (r == PAM_CRED_UNAVAIL ||
217		    r == PAM_CRED_EXPIRED ||
218		    r == PAM_USER_UNKNOWN ||
219		    r == PAM_CRED_ERR)
220			return;
221		break;
222	case PAM_SM_ACCT_MGMT:
223		if (r == PAM_USER_UNKNOWN ||
224		    r == PAM_AUTH_ERR ||
225		    r == PAM_NEW_AUTHTOK_REQD ||
226		    r == PAM_ACCT_EXPIRED)
227			return;
228		break;
229	case PAM_SM_OPEN_SESSION:
230	case PAM_SM_CLOSE_SESSION:
231		if (r == PAM_SESSION_ERR)
232			return;
233		break;
234	case PAM_SM_CHAUTHTOK:
235		if (r == PAM_PERM_DENIED ||
236		    r == PAM_AUTHTOK_ERR ||
237		    r == PAM_AUTHTOK_RECOVERY_ERR ||
238		    r == PAM_AUTHTOK_LOCK_BUSY ||
239		    r == PAM_AUTHTOK_DISABLE_AGING ||
240		    r == PAM_TRY_AGAIN)
241			return;
242		break;
243	}
244
245	openpam_log(PAM_LOG_ERROR, "%s(): unexpected return value %d",
246	    pam_sm_func_name[primitive], r);
247}
248#endif /* !defined(OPENPAM_RELAX_CHECKS) */
249
250/*
251 * NODOC
252 *
253 * Error codes:
254 */
255