1 /* $NetBSD: openpam_dispatch.c,v 1.5 2023/06/30 21:46:20 christos Exp $ */
2
3 /*-
4 * Copyright (c) 2002-2003 Networks Associates Technology, Inc.
5 * Copyright (c) 2004-2017 Dag-Erling Smørgrav
6 * All rights reserved.
7 *
8 * This software was developed for the FreeBSD Project by ThinkSec AS and
9 * Network Associates Laboratories, the Security Research Division of
10 * Network Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035
11 * ("CBOSS"), as part of the DARPA CHATS research program.
12 *
13 * Redistribution and use in source and binary forms, with or without
14 * modification, are permitted provided that the following conditions
15 * are met:
16 * 1. Redistributions of source code must retain the above copyright
17 * notice, this list of conditions and the following disclaimer.
18 * 2. Redistributions in binary form must reproduce the above copyright
19 * notice, this list of conditions and the following disclaimer in the
20 * documentation and/or other materials provided with the distribution.
21 * 3. The name of the author may not be used to endorse or promote
22 * products derived from this software without specific prior written
23 * permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 * SUCH DAMAGE.
36 */
37
38 #ifdef HAVE_CONFIG_H
39 # include "config.h"
40 #endif
41
42 #include <sys/cdefs.h>
43 __RCSID("$NetBSD: openpam_dispatch.c,v 1.5 2023/06/30 21:46:20 christos Exp $");
44
45 #include <sys/param.h>
46
47 #include <stdint.h>
48
49 #include <security/pam_appl.h>
50
51 #include "openpam_impl.h"
52
53 #if !defined(OPENPAM_RELAX_CHECKS)
54 static void openpam_check_error_code(int, int);
55 #else
56 #define openpam_check_error_code(a, b)
57 #endif /* !defined(OPENPAM_RELAX_CHECKS) */
58
59 /*
60 * OpenPAM internal
61 *
62 * Execute a module chain
63 */
64
65 int
openpam_dispatch(pam_handle_t * pamh,int primitive,int flags)66 openpam_dispatch(pam_handle_t *pamh,
67 int primitive,
68 int flags)
69 {
70 pam_chain_t *chain;
71 int err, fail, nsuccess, r;
72 int debug;
73
74 ENTER();
75
76 /* prevent recursion */
77 if (pamh->current != NULL) {
78 openpam_log(PAM_LOG_ERROR,
79 "%s() called while %s::%s() is in progress",
80 pam_func_name[primitive],
81 pamh->current->module->path,
82 pam_sm_func_name[pamh->primitive]);
83 RETURNC(PAM_ABORT);
84 }
85
86 /* pick a chain */
87 switch ((enum openpam_sm_primitives)primitive) {
88 case PAM_SM_AUTHENTICATE:
89 case PAM_SM_SETCRED:
90 chain = pamh->chains[PAM_AUTH];
91 break;
92 case PAM_SM_ACCT_MGMT:
93 chain = pamh->chains[PAM_ACCOUNT];
94 break;
95 case PAM_SM_OPEN_SESSION:
96 case PAM_SM_CLOSE_SESSION:
97 chain = pamh->chains[PAM_SESSION];
98 break;
99 case PAM_SM_CHAUTHTOK:
100 chain = pamh->chains[PAM_PASSWORD];
101 break;
102 case PAM_NUM_PRIMITIVES:
103 default:
104 RETURNC(PAM_SYSTEM_ERR);
105 }
106
107 /* execute */
108 err = PAM_SUCCESS;
109 fail = nsuccess = 0;
110 for (; chain != NULL; chain = chain->next) {
111 if (chain->module->func[primitive] == NULL) {
112 openpam_log(PAM_LOG_ERROR, "%s: no %s()",
113 chain->module->path, pam_sm_func_name[primitive]);
114 r = PAM_SYMBOL_ERR;
115 } else {
116 pamh->primitive = primitive;
117 pamh->current = chain;
118 debug = (openpam_get_option(pamh, "debug") != NULL);
119 if (debug)
120 ++openpam_debug;
121 openpam_log(PAM_LOG_LIBDEBUG, "calling %s() in %s",
122 pam_sm_func_name[primitive], chain->module->path);
123 r = (chain->module->func[primitive])(pamh, flags,
124 chain->optc, (const char **)(intptr_t)chain->optv);
125 pamh->current = NULL;
126 openpam_log(PAM_LOG_LIBDEBUG, "%s: %s(): %s",
127 chain->module->path, pam_sm_func_name[primitive],
128 pam_strerror(pamh, r));
129 if (debug)
130 --openpam_debug;
131 }
132
133 if (r == PAM_IGNORE)
134 continue;
135 if (r == PAM_SUCCESS) {
136 ++nsuccess;
137 /*
138 * For pam_setcred() and pam_chauthtok() with the
139 * PAM_PRELIM_CHECK flag, treat "sufficient" as
140 * "optional".
141 */
142 if ((chain->flag == PAM_SUFFICIENT ||
143 chain->flag == PAM_BINDING) && !fail &&
144 primitive != PAM_SM_SETCRED &&
145 !(primitive == PAM_SM_CHAUTHTOK &&
146 (flags & PAM_PRELIM_CHECK)))
147 break;
148 continue;
149 }
150
151 openpam_check_error_code(primitive, r);
152
153 /*
154 * Record the return code from the first module to
155 * fail. If a required module fails, record the
156 * return code from the first required module to fail.
157 */
158 if (err == PAM_SUCCESS)
159 err = r;
160 if ((chain->flag == PAM_REQUIRED ||
161 chain->flag == PAM_BINDING) && !fail) {
162 openpam_log(PAM_LOG_LIBDEBUG, "required module failed");
163 fail = 1;
164 err = r;
165 }
166
167 /*
168 * If a requisite module fails, terminate the chain
169 * immediately.
170 */
171 if (chain->flag == PAM_REQUISITE) {
172 openpam_log(PAM_LOG_LIBDEBUG, "requisite module failed");
173 fail = 1;
174 break;
175 }
176 }
177
178 if (!fail && err != PAM_NEW_AUTHTOK_REQD)
179 err = PAM_SUCCESS;
180
181 /*
182 * Require the chain to be non-empty, and at least one module
183 * in the chain to be successful, so that we don't fail open.
184 */
185 if (err == PAM_SUCCESS && nsuccess < 1) {
186 openpam_log(PAM_LOG_ERROR,
187 "all modules were unsuccessful for %s()",
188 pam_sm_func_name[primitive]);
189 err = PAM_SYSTEM_ERR;
190 }
191
192 RETURNC(err);
193 }
194
195 #if !defined(OPENPAM_RELAX_CHECKS)
196 static void
openpam_check_error_code(int primitive,int r)197 openpam_check_error_code(int primitive, int r)
198 {
199 /* common error codes */
200 if (r == PAM_SUCCESS ||
201 r == PAM_SYSTEM_ERR ||
202 r == PAM_SERVICE_ERR ||
203 r == PAM_BUF_ERR ||
204 r == PAM_CONV_ERR ||
205 r == PAM_PERM_DENIED ||
206 r == PAM_ABORT)
207 return;
208
209 /* specific error codes */
210 switch ((enum openpam_sm_primitives)primitive) {
211 case PAM_SM_AUTHENTICATE:
212 if (r == PAM_AUTH_ERR ||
213 r == PAM_CRED_INSUFFICIENT ||
214 r == PAM_AUTHINFO_UNAVAIL ||
215 r == PAM_USER_UNKNOWN ||
216 r == PAM_MAXTRIES)
217 return;
218 break;
219 case PAM_SM_SETCRED:
220 if (r == PAM_CRED_UNAVAIL ||
221 r == PAM_CRED_EXPIRED ||
222 r == PAM_USER_UNKNOWN ||
223 r == PAM_CRED_ERR)
224 return;
225 break;
226 case PAM_SM_ACCT_MGMT:
227 if (r == PAM_USER_UNKNOWN ||
228 r == PAM_AUTH_ERR ||
229 r == PAM_NEW_AUTHTOK_REQD ||
230 r == PAM_ACCT_EXPIRED)
231 return;
232 break;
233 case PAM_SM_OPEN_SESSION:
234 case PAM_SM_CLOSE_SESSION:
235 if (r == PAM_SESSION_ERR)
236 return;
237 break;
238 case PAM_SM_CHAUTHTOK:
239 if (r == PAM_PERM_DENIED ||
240 r == PAM_AUTHTOK_ERR ||
241 r == PAM_AUTHTOK_RECOVERY_ERR ||
242 r == PAM_AUTHTOK_LOCK_BUSY ||
243 r == PAM_AUTHTOK_DISABLE_AGING ||
244 r == PAM_TRY_AGAIN)
245 return;
246 break;
247 case PAM_NUM_PRIMITIVES:
248 break;
249 }
250
251 openpam_log(PAM_LOG_ERROR, "%s(): unexpected return value %d",
252 pam_sm_func_name[primitive], r);
253 }
254 #endif /* !defined(OPENPAM_RELAX_CHECKS) */
255
256 /*
257 * NODOC
258 *
259 * Error codes:
260 */
261