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, write to the Free Software
18 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
22 /* indicate the following groups are defined */
23 #define PAM_SM_PASSWORD
27 /* This is only used in the Sun implementation. FIXME: we really
28 want a define here that distinguishes between the Solaris PAM
29 and others (including FreeBSD). */
32 #if defined(HAVE_SECURITY_PAM_APPL_H)
33 #include <security/pam_appl.h>
34 #elif defined(HAVE_PAM_PAM_APPL_H)
35 #include <pam/pam_appl.h>
39 #if defined(HAVE_SECURITY_PAM_MODULES_H)
40 #include <security/pam_modules.h>
41 #elif defined(HAVE_PAM_PAM_MODULES_H)
42 #include <pam/pam_modules.h>
49 int smb_update_db( pam_handle_t *pamh, int ctrl, const char *user, const char *pass_new )
58 retval = NT_STATUS_IS_OK(local_password_change( user, LOCAL_SET_PASSWORD, pass_new,
59 err_str, sizeof(err_str),
60 msg_str, sizeof(msg_str) ));
64 err_str[PSTRING_LEN-1] = '\0';
65 make_remark( pamh, ctrl, PAM_ERROR_MSG, err_str );
68 /* FIXME: what value is appropriate here? */
69 retval = PAM_AUTHTOK_ERR;
72 msg_str[PSTRING_LEN-1] = '\0';
73 make_remark( pamh, ctrl, PAM_TEXT_INFO, msg_str );
84 #define _SMB_OLD_AUTHTOK "-SMB-OLD-PASS"
85 #define _SMB_NEW_AUTHTOK "-SMB-NEW-PASS"
88 * FUNCTION: pam_sm_chauthtok()
90 * This function is called twice by the PAM library, once with
91 * PAM_PRELIM_CHECK set, and then again with PAM_UPDATE_AUTHTOK set. With
92 * Linux-PAM, these two passes generally involve first checking the old
93 * token and then changing the token. This is what we do here.
95 * Having obtained a new password. The function updates the
96 * SMB_PASSWD_FILE file (normally, $(LIBDIR)/smbpasswd).
99 int pam_sm_chauthtok(pam_handle_t *pamh, int flags,
100 int argc, const char **argv)
105 extern BOOL in_client;
107 struct samu *sampass = NULL;
108 void (*oldsig_handler)(int);
113 /* Samba initialization. */
115 setup_logging( "pam_smbpass", False );
118 ctrl = set_ctrl(flags, argc, argv);
121 * First get the name of a user. No need to do anything if we can't
125 retval = pam_get_user( pamh, &user, "Username: " );
126 if (retval != PAM_SUCCESS) {
127 if (on( SMB_DEBUG, ctrl )) {
128 _log_err( LOG_DEBUG, "password: could not identify user" );
132 if (on( SMB_DEBUG, ctrl )) {
133 _log_err( LOG_DEBUG, "username [%s] obtained", user );
136 /* Getting into places that might use LDAP -- protect the app
137 from a SIGPIPE it's not expecting */
138 oldsig_handler = CatchSignal(SIGPIPE, SIGNAL_CAST SIG_IGN);
140 if (!initialize_password_db(False, NULL)) {
141 _log_err( LOG_ALERT, "Cannot access samba password database" );
142 CatchSignal(SIGPIPE, SIGNAL_CAST oldsig_handler);
143 return PAM_AUTHINFO_UNAVAIL;
146 /* obtain user record */
147 if ( !(sampass = samu_new( NULL )) ) {
148 CatchSignal(SIGPIPE, SIGNAL_CAST oldsig_handler);
149 return nt_status_to_pam(NT_STATUS_NO_MEMORY);
152 if (!pdb_getsampwnam(sampass,user)) {
153 _log_err( LOG_ALERT, "Failed to find entry for user %s.", user );
154 CatchSignal(SIGPIPE, SIGNAL_CAST oldsig_handler);
155 return PAM_USER_UNKNOWN;
157 if (on( SMB_DEBUG, ctrl )) {
158 _log_err( LOG_DEBUG, "Located account for %s", user );
161 if (flags & PAM_PRELIM_CHECK) {
163 * obtain and verify the current password (OLDAUTHTOK) for
169 if (_smb_blankpasswd( ctrl, sampass )) {
171 TALLOC_FREE(sampass);
172 CatchSignal(SIGPIPE, SIGNAL_CAST oldsig_handler);
176 /* Password change by root, or for an expired token, doesn't
177 require authentication. Is this a good choice? */
178 if (getuid() != 0 && !(flags & PAM_CHANGE_EXPIRED_AUTHTOK)) {
180 /* tell user what is happening */
181 #define greeting "Changing password for "
182 Announce = SMB_MALLOC_ARRAY(char, sizeof(greeting)+strlen(user));
183 if (Announce == NULL) {
184 _log_err(LOG_CRIT, "password: out of memory");
185 TALLOC_FREE(sampass);
186 CatchSignal(SIGPIPE, SIGNAL_CAST oldsig_handler);
189 strncpy( Announce, greeting, sizeof(greeting) );
190 strncpy( Announce+sizeof(greeting)-1, user, strlen(user)+1 );
193 set( SMB__OLD_PASSWD, ctrl );
194 retval = _smb_read_password( pamh, ctrl, Announce, "Current SMB password: ",
195 NULL, _SMB_OLD_AUTHTOK, &pass_old );
196 SAFE_FREE( Announce );
198 if (retval != PAM_SUCCESS) {
200 , "password - (old) token not obtained" );
201 TALLOC_FREE(sampass);
202 CatchSignal(SIGPIPE, SIGNAL_CAST oldsig_handler);
206 /* verify that this is the password for this user */
208 retval = _smb_verify_password( pamh, sampass, pass_old, ctrl );
212 retval = PAM_SUCCESS; /* root doesn't have to */
216 TALLOC_FREE(sampass);
217 CatchSignal(SIGPIPE, SIGNAL_CAST oldsig_handler);
220 } else if (flags & PAM_UPDATE_AUTHTOK) {
223 * obtain the proposed password
227 * get the old token back. NULL was ok only if root [at this
228 * point we assume that this has already been enforced on a
229 * previous call to this function].
232 if (off( SMB_NOT_SET_PASS, ctrl )) {
233 retval = pam_get_item( pamh, PAM_OLDAUTHTOK,
234 (const void **)&pass_old );
236 retval = pam_get_data( pamh, _SMB_OLD_AUTHTOK,
237 (const void **)&pass_old );
238 if (retval == PAM_NO_MODULE_DATA) {
240 retval = PAM_SUCCESS;
244 if (retval != PAM_SUCCESS) {
245 _log_err( LOG_NOTICE, "password: user not authenticated" );
246 TALLOC_FREE(sampass);
247 CatchSignal(SIGPIPE, SIGNAL_CAST oldsig_handler);
252 * use_authtok is to force the use of a previously entered
253 * password -- needed for pluggable password strength checking
254 * or other module stacking
257 if (on( SMB_USE_AUTHTOK, ctrl )) {
258 set( SMB_USE_FIRST_PASS, ctrl );
261 retval = _smb_read_password( pamh, ctrl
263 , "Enter new SMB password: "
264 , "Retype new SMB password: "
268 if (retval != PAM_SUCCESS) {
269 if (on( SMB_DEBUG, ctrl )) {
271 , "password: new password not obtained" );
273 pass_old = NULL; /* tidy up */
274 TALLOC_FREE(sampass);
275 CatchSignal(SIGPIPE, SIGNAL_CAST oldsig_handler);
280 * At this point we know who the user is and what they
281 * propose as their new password. Verify that the new
282 * password is acceptable.
285 if (pass_new[0] == '\0') { /* "\0" password = NULL */
289 retval = _pam_smb_approve_pass(pamh, ctrl, pass_old, pass_new);
291 if (retval != PAM_SUCCESS) {
292 _log_err(LOG_NOTICE, "new password not acceptable");
293 pass_new = pass_old = NULL; /* tidy up */
294 TALLOC_FREE(sampass);
295 CatchSignal(SIGPIPE, SIGNAL_CAST oldsig_handler);
300 * By reaching here we have approved the passwords and must now
301 * rebuild the smb password file.
304 /* update the password database */
306 retval = smb_update_db(pamh, ctrl, user, pass_new);
307 if (retval == PAM_SUCCESS) {
310 /* password updated */
311 if (!sid_to_uid(pdb_get_user_sid(sampass), &uid)) {
312 _log_err( LOG_NOTICE, "Unable to get uid for user %s",
313 pdb_get_username(sampass));
314 _log_err( LOG_NOTICE, "password for (%s) changed by (%s/%d)",
315 user, uidtoname(getuid()), getuid());
317 _log_err( LOG_NOTICE, "password for (%s/%d) changed by (%s/%d)",
318 user, uid, uidtoname(getuid()), getuid());
321 _log_err( LOG_ERR, "password change failed for user %s", user);
324 pass_old = pass_new = NULL;
326 TALLOC_FREE(sampass);
330 } else { /* something has broken with the library */
332 _log_err( LOG_ALERT, "password received unknown request" );
338 TALLOC_FREE(sampass);
342 TALLOC_FREE(sampass);
343 CatchSignal(SIGPIPE, SIGNAL_CAST oldsig_handler);
347 /* static module data */
349 struct pam_module _pam_smbpass_passwd_modstruct = {