xref: /freebsd/contrib/openpam/lib/libpam/openpam_dispatch.c (revision f4b37ed0f8b307b1f3f0f630ca725d68f1dff30d)
1 /*-
2  * Copyright (c) 2002-2003 Networks Associates Technology, Inc.
3  * Copyright (c) 2004-2011 Dag-Erling Smørgrav
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)
49 static 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 
60 int
61 openpam_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)
192 static void
193 openpam_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