2 Unix SMB/CIFS implementation.
3 Use PAM to update user passwords in the local SAM
4 Copyright (C) Steve Langasek 1998-2003
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program. If not, see <http://www.gnu.org/licenses/>.
21 /* indicate the following groups are defined */
22 #define PAM_SM_PASSWORD
26 /* This is only used in the Sun implementation. FIXME: we really
27 want a define here that distinguishes between the Solaris PAM
28 and others (including FreeBSD). */
31 #if defined(HAVE_SECURITY_PAM_APPL_H)
32 #include <security/pam_appl.h>
33 #elif defined(HAVE_PAM_PAM_APPL_H)
34 #include <pam/pam_appl.h>
38 #if defined(HAVE_SECURITY_PAM_MODULES_H)
39 #include <security/pam_modules.h>
40 #elif defined(HAVE_PAM_PAM_MODULES_H)
41 #include <pam/pam_modules.h>
48 int smb_update_db( pam_handle_t *pamh, int ctrl, const char *user, const char *pass_new )
54 retval = NT_STATUS_IS_OK(local_password_change(user, LOCAL_SET_PASSWORD, pass_new,
60 make_remark(pamh, ctrl, PAM_ERROR_MSG, err_str );
63 /* FIXME: what value is appropriate here? */
64 retval = PAM_AUTHTOK_ERR;
67 make_remark(pamh, ctrl, PAM_TEXT_INFO, msg_str );
80 #define _SMB_OLD_AUTHTOK "-SMB-OLD-PASS"
81 #define _SMB_NEW_AUTHTOK "-SMB-NEW-PASS"
84 * FUNCTION: pam_sm_chauthtok()
86 * This function is called twice by the PAM library, once with
87 * PAM_PRELIM_CHECK set, and then again with PAM_UPDATE_AUTHTOK set. With
88 * Linux-PAM, these two passes generally involve first checking the old
89 * token and then changing the token. This is what we do here.
91 * Having obtained a new password. The function updates the
92 * SMB_PASSWD_FILE file (normally, $(LIBDIR)/smbpasswd).
95 int pam_sm_chauthtok(pam_handle_t *pamh, int flags,
96 int argc, const char **argv)
101 extern bool in_client;
103 struct samu *sampass = NULL;
104 void (*oldsig_handler)(int);
109 /* Samba initialization. */
111 setup_logging( "pam_smbpass", False );
114 ctrl = set_ctrl(flags, argc, argv);
117 * First get the name of a user. No need to do anything if we can't
121 retval = pam_get_user( pamh, &user, "Username: " );
122 if (retval != PAM_SUCCESS) {
123 if (on( SMB_DEBUG, ctrl )) {
124 _log_err( LOG_DEBUG, "password: could not identify user" );
128 if (on( SMB_DEBUG, ctrl )) {
129 _log_err( LOG_DEBUG, "username [%s] obtained", user );
132 /* Getting into places that might use LDAP -- protect the app
133 from a SIGPIPE it's not expecting */
134 oldsig_handler = CatchSignal(SIGPIPE, SIGNAL_CAST SIG_IGN);
136 if (!initialize_password_db(False, NULL)) {
137 _log_err( LOG_ALERT, "Cannot access samba password database" );
138 CatchSignal(SIGPIPE, SIGNAL_CAST oldsig_handler);
139 return PAM_AUTHINFO_UNAVAIL;
142 /* obtain user record */
143 if ( !(sampass = samu_new( NULL )) ) {
144 CatchSignal(SIGPIPE, SIGNAL_CAST oldsig_handler);
145 return nt_status_to_pam(NT_STATUS_NO_MEMORY);
148 if (!pdb_getsampwnam(sampass,user)) {
149 _log_err( LOG_ALERT, "Failed to find entry for user %s.", user );
150 CatchSignal(SIGPIPE, SIGNAL_CAST oldsig_handler);
151 return PAM_USER_UNKNOWN;
153 if (on( SMB_DEBUG, ctrl )) {
154 _log_err( LOG_DEBUG, "Located account for %s", user );
157 if (flags & PAM_PRELIM_CHECK) {
159 * obtain and verify the current password (OLDAUTHTOK) for
165 if (_smb_blankpasswd( ctrl, sampass )) {
167 TALLOC_FREE(sampass);
168 CatchSignal(SIGPIPE, SIGNAL_CAST oldsig_handler);
172 /* Password change by root, or for an expired token, doesn't
173 require authentication. Is this a good choice? */
174 if (getuid() != 0 && !(flags & PAM_CHANGE_EXPIRED_AUTHTOK)) {
176 /* tell user what is happening */
177 #define greeting "Changing password for "
178 Announce = SMB_MALLOC_ARRAY(char, sizeof(greeting)+strlen(user));
179 if (Announce == NULL) {
180 _log_err(LOG_CRIT, "password: out of memory");
181 TALLOC_FREE(sampass);
182 CatchSignal(SIGPIPE, SIGNAL_CAST oldsig_handler);
185 strncpy( Announce, greeting, sizeof(greeting) );
186 strncpy( Announce+sizeof(greeting)-1, user, strlen(user)+1 );
189 set( SMB__OLD_PASSWD, ctrl );
190 retval = _smb_read_password( pamh, ctrl, Announce, "Current SMB password: ",
191 NULL, _SMB_OLD_AUTHTOK, &pass_old );
192 SAFE_FREE( Announce );
194 if (retval != PAM_SUCCESS) {
196 , "password - (old) token not obtained" );
197 TALLOC_FREE(sampass);
198 CatchSignal(SIGPIPE, SIGNAL_CAST oldsig_handler);
202 /* verify that this is the password for this user */
204 retval = _smb_verify_password( pamh, sampass, pass_old, ctrl );
208 retval = PAM_SUCCESS; /* root doesn't have to */
212 TALLOC_FREE(sampass);
213 CatchSignal(SIGPIPE, SIGNAL_CAST oldsig_handler);
216 } else if (flags & PAM_UPDATE_AUTHTOK) {
219 * obtain the proposed password
223 * get the old token back. NULL was ok only if root [at this
224 * point we assume that this has already been enforced on a
225 * previous call to this function].
228 if (off( SMB_NOT_SET_PASS, ctrl )) {
229 retval = pam_get_item( pamh, PAM_OLDAUTHTOK,
230 (const void **)&pass_old );
232 retval = pam_get_data( pamh, _SMB_OLD_AUTHTOK,
233 (const void **)&pass_old );
234 if (retval == PAM_NO_MODULE_DATA) {
236 retval = PAM_SUCCESS;
240 if (retval != PAM_SUCCESS) {
241 _log_err( LOG_NOTICE, "password: user not authenticated" );
242 TALLOC_FREE(sampass);
243 CatchSignal(SIGPIPE, SIGNAL_CAST oldsig_handler);
248 * use_authtok is to force the use of a previously entered
249 * password -- needed for pluggable password strength checking
250 * or other module stacking
253 if (on( SMB_USE_AUTHTOK, ctrl )) {
254 set( SMB_USE_FIRST_PASS, ctrl );
257 retval = _smb_read_password( pamh, ctrl
259 , "Enter new SMB password: "
260 , "Retype new SMB password: "
264 if (retval != PAM_SUCCESS) {
265 if (on( SMB_DEBUG, ctrl )) {
267 , "password: new password not obtained" );
269 pass_old = NULL; /* tidy up */
270 TALLOC_FREE(sampass);
271 CatchSignal(SIGPIPE, SIGNAL_CAST oldsig_handler);
276 * At this point we know who the user is and what they
277 * propose as their new password. Verify that the new
278 * password is acceptable.
281 if (pass_new[0] == '\0') { /* "\0" password = NULL */
285 retval = _pam_smb_approve_pass(pamh, ctrl, pass_old, pass_new);
287 if (retval != PAM_SUCCESS) {
288 _log_err(LOG_NOTICE, "new password not acceptable");
289 pass_new = pass_old = NULL; /* tidy up */
290 TALLOC_FREE(sampass);
291 CatchSignal(SIGPIPE, SIGNAL_CAST oldsig_handler);
296 * By reaching here we have approved the passwords and must now
297 * rebuild the smb password file.
300 /* update the password database */
302 retval = smb_update_db(pamh, ctrl, user, pass_new);
303 if (retval == PAM_SUCCESS) {
306 /* password updated */
307 if (!sid_to_uid(pdb_get_user_sid(sampass), &uid)) {
308 _log_err( LOG_NOTICE, "Unable to get uid for user %s",
309 pdb_get_username(sampass));
310 _log_err( LOG_NOTICE, "password for (%s) changed by (%s/%d)",
311 user, uidtoname(getuid()), getuid());
313 _log_err( LOG_NOTICE, "password for (%s/%d) changed by (%s/%d)",
314 user, uid, uidtoname(getuid()), getuid());
317 _log_err( LOG_ERR, "password change failed for user %s", user);
320 pass_old = pass_new = NULL;
322 TALLOC_FREE(sampass);
326 } else { /* something has broken with the library */
328 _log_err( LOG_ALERT, "password received unknown request" );
334 TALLOC_FREE(sampass);
338 TALLOC_FREE(sampass);
339 CatchSignal(SIGPIPE, SIGNAL_CAST oldsig_handler);
343 /* static module data */
345 struct pam_module _pam_smbpass_passwd_modstruct = {