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/* Unix NT password database implementation, version 0.7.5.
*
* This program is free software; you can redistribute it and/or modify it under
* the terms of the GNU General Public License as published by the Free
* Software Foundation; either version 2 of the License, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc., 675
* Mass Ave, Cambridge, MA 02139, USA.
*/
/* indicate the following groups are defined */
#define PAM_SM_PASSWORD
#include "includes.h"
#ifndef LINUX
/* This is only used in the Sun implementation. */
#include <security/pam_appl.h>
#endif /* LINUX */
#include <security/pam_modules.h>
#include "general.h"
#include "support.h"
int smb_update_db( pam_handle_t *pamh, int ctrl, const char *user
, const char *pass_new )
{
char c;
int retval, i;
pstring err_str;
pstring msg_str;
err_str[0] = '\0';
msg_str[0] = '\0';
retval = local_password_change( user, LOCAL_SET_PASSWORD, pass_new, err_str, sizeof(err_str),
msg_str, sizeof(msg_str) );
if (!retval) {
if (*err_str) {
err_str[PSTRING_LEN-1] = '\0';
make_remark( pamh, ctrl, PAM_ERROR_MSG, err_str );
}
/* FIXME: what value is appropriate here? */
retval = PAM_AUTHTOK_ERR;
} else {
if (*msg_str) {
msg_str[PSTRING_LEN-1] = '\0';
make_remark( pamh, ctrl, PAM_TEXT_INFO, msg_str );
}
retval = PAM_SUCCESS;
}
return retval;
}
/* data tokens */
#define _SMB_OLD_AUTHTOK "-SMB-OLD-PASS"
#define _SMB_NEW_AUTHTOK "-SMB-NEW-PASS"
/*
* FUNCTION: pam_sm_chauthtok()
*
* This function is called twice by the PAM library, once with
* PAM_PRELIM_CHECK set, and then again with PAM_UPDATE_AUTHTOK set. With
* Linux-PAM, these two passes generally involve first checking the old
* token and then changing the token. This is what we do here.
*
* Having obtained a new password. The function updates the
* SMB_PASSWD_FILE file (normally, $(LIBDIR)/smbpasswd).
*/
int pam_sm_chauthtok(pam_handle_t *pamh, int flags,
int argc, const char **argv)
{
unsigned int ctrl;
int retval;
extern BOOL in_client;
struct smb_passwd *smb_pwent=NULL;
const char *user;
const char *pass_old, *pass_new;
/* Samba initialization. */
setup_logging( "pam_smbpass", False );
in_client = True;
ctrl = set_ctrl(flags, argc, argv);
/*
* First get the name of a user. No need to do anything if we can't
* determine this.
*/
retval = pam_get_user( pamh, &user, "Username: " );
if (retval != PAM_SUCCESS) {
if (on( SMB_DEBUG, ctrl )) {
_log_err( LOG_DEBUG, "password: could not identify user" );
}
return retval;
}
if (on( SMB_DEBUG, ctrl )) {
_log_err( LOG_DEBUG, "username [%s] obtained", user );
}
if (!initialize_password_db(True)) {
_log_err( LOG_ALERT, "Cannot access samba password database" );
return PAM_AUTHINFO_UNAVAIL;
}
/* obtain user record */
smb_pwent = getsmbpwnam(user);
if (smb_pwent == NULL) {
_log_err( LOG_ALERT, "Failed to find entry for user %s.", user );
return PAM_USER_UNKNOWN;
}
if (flags & PAM_PRELIM_CHECK) {
/*
* obtain and verify the current password (OLDAUTHTOK) for
* the user.
*/
char *Announce;
if (_smb_blankpasswd( ctrl, smb_pwent )) {
return PAM_SUCCESS;
}
/* Password change by root, or for an expired token, doesn't
require authentication. Is this a good choice? */
if (getuid() != 0 && !(flags & PAM_CHANGE_EXPIRED_AUTHTOK)) {
/* tell user what is happening */
#define greeting "Changing password for "
Announce = (char *) malloc(sizeof(greeting)+strlen(user));
if (Announce == NULL) {
_log_err(LOG_CRIT, "password: out of memory");
return PAM_BUF_ERR;
}
strncpy( Announce, greeting, sizeof(greeting) );
strncpy( Announce+sizeof(greeting)-1, user, strlen(user)+1 );
#undef greeting
set( SMB__OLD_PASSWD, ctrl );
retval = _smb_read_password( pamh, ctrl
, Announce
, "Current SMB password: "
, NULL
, _SMB_OLD_AUTHTOK
, &pass_old );
free( Announce );
if (retval != PAM_SUCCESS) {
_log_err( LOG_NOTICE
, "password - (old) token not obtained" );
return retval;
}
/* verify that this is the password for this user */
retval = _smb_verify_password( pamh, smb_pwent, pass_old, ctrl );
} else {
pass_old = NULL;
retval = PAM_SUCCESS; /* root doesn't have to */
}
pass_old = NULL;
return retval;
} else if (flags & PAM_UPDATE_AUTHTOK) {
if (flags & PAM_CHANGE_EXPIRED_AUTHTOK) {
/* NOTE: there is currently no support for password expiring
under Samba. Support will be added here when it becomes
available. */
return PAM_SUCCESS;
}
/*
* obtain the proposed password
*/
/*
* get the old token back. NULL was ok only if root [at this
* point we assume that this has already been enforced on a
* previous call to this function].
*/
if (off( SMB_NOT_SET_PASS, ctrl )) {
retval = pam_get_item( pamh, PAM_OLDAUTHTOK,
(const void **)&pass_old );
} else {
retval = pam_get_data( pamh, _SMB_OLD_AUTHTOK,
(const void **)&pass_old );
if (retval == PAM_NO_MODULE_DATA) {
pass_old = NULL;
retval = PAM_SUCCESS;
}
}
if (retval != PAM_SUCCESS) {
_log_err( LOG_NOTICE, "password: user not authenticated" );
return retval;
}
/*
* use_authtok is to force the use of a previously entered
* password -- needed for pluggable password strength checking
* or other module stacking
*/
if (on( SMB_USE_AUTHTOK, ctrl )) {
set( SMB_USE_FIRST_PASS, ctrl );
}
retval = _smb_read_password( pamh, ctrl
, NULL
, "Enter new SMB password: "
, "Retype new SMB password: "
, _SMB_NEW_AUTHTOK
, &pass_new );
if (retval != PAM_SUCCESS) {
if (on( SMB_DEBUG, ctrl )) {
_log_err( LOG_ALERT
, "password: new password not obtained" );
}
pass_old = NULL; /* tidy up */
return retval;
}
/*
* At this point we know who the user is and what they
* propose as their new password. Verify that the new
* password is acceptable.
*/
if (pass_new[0] == '\0') { /* "\0" password = NULL */
pass_new = NULL;
}
retval = _pam_smb_approve_pass(pamh, ctrl, pass_old, pass_new);
if (retval != PAM_SUCCESS) {
_log_err(LOG_NOTICE, "new password not acceptable");
pass_new = pass_old = NULL; /* tidy up */
return retval;
}
/*
* By reaching here we have approved the passwords and must now
* rebuild the smb password file.
*/
/* update the password database */
retval = smb_update_db(pamh, ctrl, user, pass_new);
if (retval == PAM_SUCCESS) {
/* password updated */
_log_err( LOG_NOTICE, "password for (%s/%d) changed by (%s/%d)"
, user, smb_pwent->smb_userid, uidtoname( getuid() )
, getuid() );
} else {
_log_err( LOG_ERR, "password change failed for user %s"
, user );
}
pass_old = pass_new = NULL;
smb_pwent = NULL;
} else { /* something has broken with the library */
_log_err( LOG_ALERT, "password received unknown request" );
retval = PAM_ABORT;
}
return retval;
}
/* static module data */
#ifdef PAM_STATIC
struct pam_module _pam_smbpass_passwd_modstruct = {
"pam_smbpass",
NULL,
NULL,
NULL,
NULL,
NULL,
pam_sm_chauthtok
};
#endif
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