1 /*
2 * pam_unix account management
3 *
4 * Copyright Elliot Lee, 1996. All rights reserved.
5 * Copyright Jan Rękorajski, 1999. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, and the entire permission notice in its entirety,
12 * including the disclaimer of warranties.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. The name of the author may not be used to endorse or promote
17 * products derived from this software without specific prior
18 * written permission.
19 *
20 * ALTERNATIVELY, this product may be distributed under the terms of
21 * the GNU Public License, in which case the provisions of the GPL are
22 * required INSTEAD OF the above restrictions. (This clause is
23 * necessary due to a potential bad interaction between the GPL and
24 * the restrictions contained in a BSD-style copyright.)
25 *
26 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
27 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
28 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
29 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
30 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
31 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
32 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
34 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
36 * OF THE POSSIBILITY OF SUCH DAMAGE.
37 */
38
39 #include "config.h"
40
41 #include <stdlib.h>
42 #include <stdio.h>
43 #include <string.h>
44 #include <unistd.h>
45 #include <sys/types.h>
46 #include <sys/resource.h>
47 #include <syslog.h>
48 #include <pwd.h>
49 #include <shadow.h>
50 #include <time.h> /* for time() */
51 #include <errno.h>
52 #include <sys/wait.h>
53
54 #include <security/_pam_macros.h>
55
56 #include <security/pam_modules.h>
57 #include <security/pam_ext.h>
58 #include <security/pam_modutil.h>
59
60 #include "pam_cc_compat.h"
61 #include "support.h"
62 #include "passverify.h"
63
64 int _unix_run_verify_binary(pam_handle_t *pamh, unsigned long long ctrl,
65 const char *user, int *daysleft)
66 {
67 int retval=0, child, fds[2];
68 struct sigaction newsa, oldsa;
69 D(("running verify_binary"));
70
71 /* create a pipe for the messages */
72 if (pipe(fds) != 0) {
73 D(("could not make pipe"));
74 pam_syslog(pamh, LOG_ERR, "Could not make pipe: %m");
75 return PAM_AUTH_ERR;
76 }
77 D(("called."));
78
79 if (off(UNIX_NOREAP, ctrl)) {
80 /*
81 * This code arranges that the demise of the child does not cause
82 * the application to receive a signal it is not expecting - which
83 * may kill the application or worse.
84 *
85 * The "noreap" module argument is provided so that the admin can
86 * override this behavior.
87 */
88 memset(&newsa, '\0', sizeof(newsa));
89 newsa.sa_handler = SIG_DFL;
90 sigaction(SIGCHLD, &newsa, &oldsa);
91 }
92
93 /* fork */
94 child = fork();
95 if (child == 0) {
96 static char *envp[] = { NULL };
97 const char *args[] = { NULL, NULL, NULL, NULL };
98
99 /* XXX - should really tidy up PAM here too */
100
101 /* reopen stdout as pipe */
102 if (dup2(fds[1], STDOUT_FILENO) != STDOUT_FILENO) {
103 pam_syslog(pamh, LOG_ERR, "dup2 of %s failed: %m", "stdout");
104 _exit(PAM_AUTHINFO_UNAVAIL);
105 }
106
107 if (pam_modutil_sanitize_helper_fds(pamh, PAM_MODUTIL_PIPE_FD,
108 PAM_MODUTIL_IGNORE_FD,
109 PAM_MODUTIL_PIPE_FD) < 0) {
110 _exit(PAM_AUTHINFO_UNAVAIL);
111 }
112
113 if (geteuid() == 0) {
114 /* must set the real uid to 0 so the helper will not error
115 out if pam is called from setuid binary (su, sudo...) */
116 if (setuid(0) == -1) {
117 pam_syslog(pamh, LOG_ERR, "setuid failed: %m");
118 printf("-1\n");
119 fflush(stdout);
120 _exit(PAM_AUTHINFO_UNAVAIL);
121 }
122 }
123
124 /* exec binary helper */
125 args[0] = CHKPWD_HELPER;
126 args[1] = user;
127 args[2] = "chkexpiry";
128
129 DIAG_PUSH_IGNORE_CAST_QUAL;
130 execve(CHKPWD_HELPER, (char *const *) args, envp);
131 DIAG_POP_IGNORE_CAST_QUAL;
132
133 pam_syslog(pamh, LOG_ERR, "helper binary execve failed: %m");
134 /* should not get here: exit with error */
135 D(("helper binary is not available"));
136 printf("-1\n");
137 fflush(stdout);
138 _exit(PAM_AUTHINFO_UNAVAIL);
139 } else {
140 close(fds[1]);
141 if (child > 0) {
142 char buf[32];
143 int rc=0;
144 /* wait for helper to complete: */
145 while ((rc=waitpid(child, &retval, 0)) < 0 && errno == EINTR);
146 if (rc<0) {
147 pam_syslog(pamh, LOG_ERR, "unix_chkpwd waitpid returned %d: %m", rc);
148 retval = PAM_AUTH_ERR;
149 } else if (!WIFEXITED(retval)) {
150 pam_syslog(pamh, LOG_ERR, "unix_chkpwd abnormal exit: %d", retval);
151 retval = PAM_AUTH_ERR;
152 } else {
153 retval = WEXITSTATUS(retval);
154 rc = pam_modutil_read(fds[0], buf, sizeof(buf) - 1);
155 if(rc > 0) {
156 buf[rc] = '\0';
157 if (sscanf(buf,"%d", daysleft) != 1 )
158 retval = PAM_AUTH_ERR;
159 }
160 else {
161 pam_syslog(pamh, LOG_ERR, "read unix_chkpwd output error %d: %m", rc);
162 retval = PAM_AUTH_ERR;
163 }
164 }
165 } else {
166 pam_syslog(pamh, LOG_ERR, "Fork failed: %m");
167 D(("fork failed"));
168 retval = PAM_AUTH_ERR;
169 }
170 close(fds[0]);
171 }
172
173 if (off(UNIX_NOREAP, ctrl)) {
174 sigaction(SIGCHLD, &oldsa, NULL); /* restore old signal handler */
175 }
176
177 D(("Returning %d",retval));
178 return retval;
179 }
180
181 /*
182 * PAM framework looks for this entry-point to pass control to the
183 * account management module.
184 */
185
186 int
187 pam_sm_acct_mgmt(pam_handle_t *pamh, int flags, int argc, const char **argv)
188 {
189 unsigned long long ctrl;
190 const void *void_uname;
191 const char *uname;
192 int retval, daysleft = -1;
193 char buf[256];
194
195 D(("called."));
196
197 ctrl = _set_ctrl(pamh, flags, NULL, NULL, NULL, argc, argv);
198
199 retval = pam_get_item(pamh, PAM_USER, &void_uname);
200 uname = void_uname;
201 D(("user = `%s'", uname));
202 if (retval != PAM_SUCCESS || uname == NULL) {
203 pam_syslog(pamh, LOG_ERR,
204 "could not identify user (from uid=%lu)",
205 (unsigned long int)getuid());
206 return PAM_USER_UNKNOWN;
207 }
208
209 retval = _unix_verify_user(pamh, ctrl, uname, &daysleft);
210
211 if (on(UNIX_NO_PASS_EXPIRY, ctrl)) {
212 const void *pretval = NULL;
213 int authrv = PAM_AUTHINFO_UNAVAIL; /* authentication not called */
214
215 if (pam_get_data(pamh, "unix_setcred_return", &pretval) == PAM_SUCCESS
216 && pretval)
217 authrv = *(const int *)pretval;
218
219 if (authrv != PAM_SUCCESS
220 && (retval == PAM_NEW_AUTHTOK_REQD || retval == PAM_AUTHTOK_EXPIRED))
221 retval = PAM_SUCCESS;
222 }
223
224 switch (retval) {
225 case PAM_ACCT_EXPIRED:
226 pam_syslog(pamh, LOG_NOTICE,
227 "account %s has expired (account expired)",
228 uname);
229 _make_remark(pamh, ctrl, PAM_ERROR_MSG,
230 _("Your account has expired; please contact your system administrator."));
231 break;
232 case PAM_NEW_AUTHTOK_REQD:
233 if (daysleft == 0) {
234 pam_syslog(pamh, LOG_NOTICE,
235 "expired password for user %s (root enforced)",
236 uname);
237 _make_remark(pamh, ctrl, PAM_ERROR_MSG,
238 _("You are required to change your password immediately (administrator enforced)."));
239 } else {
240 pam_syslog(pamh, LOG_DEBUG,
241 "expired password for user %s (password aged)",
242 uname);
243 _make_remark(pamh, ctrl, PAM_ERROR_MSG,
244 _("You are required to change your password immediately (password expired)."));
245 }
246 break;
247 case PAM_AUTHTOK_EXPIRED:
248 pam_syslog(pamh, LOG_NOTICE,
249 "account %s has expired (failed to change password)",
250 uname);
251 _make_remark(pamh, ctrl, PAM_ERROR_MSG,
252 _("Your account has expired; please contact your system administrator."));
253 break;
254 case PAM_AUTHTOK_ERR:
255 /*
256 * We ignore "password changed too early" error
257 * as it is relevant only for password change.
258 */
259 retval = PAM_SUCCESS;
260 /* fallthrough */
261 case PAM_SUCCESS:
262 if (daysleft >= 0) {
263 pam_syslog(pamh, LOG_DEBUG,
264 "password for user %s will expire in %d days",
265 uname, daysleft);
266 #if defined HAVE_DNGETTEXT && defined ENABLE_NLS
267 snprintf (buf, sizeof (buf),
268 dngettext(PACKAGE,
269 "Warning: your password will expire in %d day.",
270 "Warning: your password will expire in %d days.",
271 daysleft),
272 daysleft);
273 #else
274 if (daysleft == 1)
275 snprintf(buf, sizeof (buf),
276 _("Warning: your password will expire in %d day."),
277 daysleft);
278 else
279 snprintf(buf, sizeof (buf),
280 /* TRANSLATORS: only used if dngettext is not supported */
281 _("Warning: your password will expire in %d days."),
282 daysleft);
283 #endif
284 _make_remark(pamh, ctrl, PAM_TEXT_INFO, buf);
285 }
286 }
287
288 D(("all done"));
289
290 return retval;
291 }