PAM_EXTERN int pam_sm_chauthtok(pam_handle_t * pamh, int flags,
int argc, const char **argv)
{
unsigned int ctrl, lctrl;
int retval, i;
int remember = -1;
/* <DO NOT free() THESE> */
const char *user;
char *pass_old, *pass_new;
/* </DO NOT free() THESE> */
D(("called."));
#ifdef USE_LCKPWDF
/* our current locking system requires that we lock the
entire password database. This avoids both livelock
and deadlock. */
/* These values for the number of attempts and the sleep time
are, of course, completely arbitrary.
My reading of the PAM docs is that, once pam_chauthtok() has been
called with PAM_UPDATE_AUTHTOK, we are obliged to take any
reasonable steps to make sure the token is updated; so retrying
for 1/10 sec. isn't overdoing it.
The other possibility is to call lckpwdf() on the first
pam_chauthtok() pass, and hold the lock until released in the
second pass--but is this guaranteed to work? -SRL */
i=0;
while((retval = lckpwdf()) != 0 && i < 100) {
usleep(1000);
}
if(retval != 0) {
return PAM_AUTHTOK_LOCK_BUSY;
}
#endif
ctrl = _set_ctrl(pamh, flags, &remember, argc, argv);
/*
* First get the name of a user
*/
retval = pam_get_user(pamh, &user, "Username: "******"bad username [%s]", user);
#ifdef USE_LCKPWDF
ulckpwdf();
#endif
return PAM_USER_UNKNOWN;
}
if (retval == PAM_SUCCESS && on(UNIX_DEBUG, ctrl))
_log_err(LOG_DEBUG, pamh, "username [%s] obtained",
user);
} else {
if (on(UNIX_DEBUG, ctrl))
_log_err(LOG_DEBUG, pamh,
"password - could not identify user");
#ifdef USE_LCKPWDF
ulckpwdf();
#endif
return retval;
}
D(("Got username of %s", user));
/*
* This is not an AUTH module!
*/
if (on(UNIX__NONULL, ctrl))
set(UNIX__NULLOK, ctrl);
if (on(UNIX__PRELIM, ctrl)) {
/*
* obtain and verify the current password (OLDAUTHTOK) for
* the user.
*/
char *Announce;
D(("prelim check"));
if (_unix_blankpasswd(ctrl, user)) {
#ifdef USE_LCKPWDF
ulckpwdf();
#endif
return PAM_SUCCESS;
} else if (off(UNIX__IAMROOT, ctrl)) {
/* instruct user what is happening */
#define greeting "Changing password for "
Announce = (char *) malloc(sizeof(greeting) + strlen(user));
if (Announce == NULL) {
_log_err(LOG_CRIT, pamh,
"password - out of memory");
#ifdef USE_LCKPWDF
ulckpwdf();
#endif
return PAM_BUF_ERR;
}
(void) strcpy(Announce, greeting);
(void) strcpy(Announce + sizeof(greeting) - 1, user);
#undef greeting
lctrl = ctrl;
set(UNIX__OLD_PASSWD, lctrl);
retval = _unix_read_password(pamh, lctrl
,Announce
,"(current) UNIX password: "******"password - (old) token not obtained");
#ifdef USE_LCKPWDF
ulckpwdf();
#endif
return retval;
}
/* verify that this is the password for this user */
retval = _unix_verify_password(pamh, user, pass_old, ctrl);
} else {
D(("process run by root so do nothing this time around"));
pass_old = NULL;
retval = PAM_SUCCESS; /* root doesn't have too */
}
if (retval != PAM_SUCCESS) {
D(("Authentication failed"));
pass_old = NULL;
#ifdef USE_LCKPWDF
ulckpwdf();
#endif
return retval;
}
retval = pam_set_item(pamh, PAM_OLDAUTHTOK, (const void *) pass_old);
pass_old = NULL;
if (retval != PAM_SUCCESS) {
_log_err(LOG_CRIT, pamh,
"failed to set PAM_OLDAUTHTOK");
}
retval = _unix_verify_shadow(user, ctrl);
if (retval == PAM_AUTHTOK_ERR) {
if (off(UNIX__IAMROOT, ctrl))
_make_remark(pamh, ctrl, PAM_ERROR_MSG,
"You must wait longer to change your password");
else
retval = PAM_SUCCESS;
}
} else if (on(UNIX__UPDATE, ctrl)) {
/*
* tpass is used below to store the _pam_md() return; it
* should be _pam_delete()'d.
*/
char *tpass = NULL;
int retry = 0;
/*
* obtain the proposed password
*/
D(("do update"));
/*
* 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(UNIX_NOT_SET_PASS, ctrl)) {
retval = pam_get_item(pamh, PAM_OLDAUTHTOK
,(const void **) &pass_old);
} else {
retval = pam_get_data(pamh, _UNIX_OLD_AUTHTOK
,(const void **) &pass_old);
if (retval == PAM_NO_MODULE_DATA) {
retval = PAM_SUCCESS;
pass_old = NULL;
}
}
D(("pass_old [%s]", pass_old));
if (retval != PAM_SUCCESS) {
_log_err(LOG_NOTICE, pamh, "user not authenticated");
#ifdef USE_LCKPWDF
ulckpwdf();
#endif
return retval;
}
retval = _unix_verify_shadow(user, ctrl);
if (retval != PAM_SUCCESS) {
_log_err(LOG_NOTICE, pamh, "user not authenticated 2");
#ifdef USE_LCKPWDF
ulckpwdf();
#endif
return retval;
}
D(("get new password now"));
lctrl = ctrl;
if (on(UNIX_USE_AUTHTOK, lctrl)) {
set(UNIX_USE_FIRST_PASS, lctrl);
}
retry = 0;
retval = PAM_AUTHTOK_ERR;
while ((retval != PAM_SUCCESS) && (retry++ < MAX_PASSWD_TRIES)) {
/*
* use_authtok is to force the use of a previously entered
* password -- needed for pluggable password strength checking
*/
retval = _unix_read_password(pamh, lctrl
,NULL
,"Enter new UNIX password: "******"Retype new UNIX password: "******"password - new password not obtained");
}
pass_old = NULL; /* tidy up */
#ifdef USE_LCKPWDF
ulckpwdf();
#endif
return retval;
}
D(("returned to _unix_chauthtok"));
/*
* 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_unix_approve_pass(pamh, ctrl, pass_old, pass_new);
}
if (retval != PAM_SUCCESS) {
_log_err(LOG_NOTICE, pamh,
"new password not acceptable");
_pam_overwrite(pass_new);
_pam_overwrite(pass_old);
pass_new = pass_old = NULL; /* tidy up */
#ifdef USE_LCKPWDF
ulckpwdf();
#endif
return retval;
}
/*
* By reaching here we have approved the passwords and must now
* rebuild the password database file.
*/
/*
* First we encrypt the new password.
*/
if (on(UNIX_MD5_PASS, ctrl)) {
tpass = crypt_md5_wrapper(pass_new);
} else {
/*
* Salt manipulation is stolen from Rick Faith's passwd
* program. Sorry Rick :) -- alex
*/
time_t tm;
char salt[3];
time(&tm);
salt[0] = bin_to_ascii(tm & 0x3f);
salt[1] = bin_to_ascii((tm >> 6) & 0x3f);
salt[2] = '\0';
if (off(UNIX_BIGCRYPT, ctrl) && strlen(pass_new) > 8) {
/*
* to avoid using the _extensions_ of the bigcrypt()
* function we truncate the newly entered password
*/
char *temp = malloc(9);
char *e;
if (temp == NULL) {
_log_err(LOG_CRIT, pamh,
"out of memory for password");
_pam_overwrite(pass_new);
_pam_overwrite(pass_old);
pass_new = pass_old = NULL; /* tidy up */
#ifdef USE_LCKPWDF
ulckpwdf();
#endif
return PAM_BUF_ERR;
}
/* copy first 8 bytes of password */
strncpy(temp, pass_new, 8);
temp[8] = '\0';
/* no longer need cleartext */
e = bigcrypt(temp, salt);
tpass = x_strdup(e);
_pam_overwrite(e);
_pam_delete(temp); /* tidy up */
} else {
char *e;
/* no longer need cleartext */
e = bigcrypt(pass_new, salt);
tpass = x_strdup(e);
_pam_overwrite(e);
}
}
D(("password processed"));
/* update the password database(s) -- race conditions..? */
retval = _do_setpass(pamh, user, pass_old, tpass, ctrl,
remember);
_pam_overwrite(pass_new);
_pam_overwrite(pass_old);
_pam_delete(tpass);
pass_old = pass_new = NULL;
} else { /* something has broken with the module */
PAM_EXTERN int pam_sm_chauthtok(pam_handle_t * pamh, int flags,
int argc, const char **argv)
{
unsigned int ctrl, lctrl;
int retval;
int remember = -1;
int rounds = -1;
int pass_min_len = 0;
/* <DO NOT free() THESE> */
const char *user;
const void *pass_old, *pass_new;
/* </DO NOT free() THESE> */
D(("called."));
ctrl = _set_ctrl(pamh, flags, &remember, &rounds, &pass_min_len,
argc, argv);
/*
* First get the name of a user
*/
retval = pam_get_user(pamh, &user, NULL);
if (retval == PAM_SUCCESS) {
/*
* Various libraries at various times have had bugs related to
* '+' or '-' as the first character of a user name. Don't
* allow them.
*/
if (user == NULL || user[0] == '-' || user[0] == '+') {
pam_syslog(pamh, LOG_ERR, "bad username [%s]", user);
return PAM_USER_UNKNOWN;
}
if (retval == PAM_SUCCESS && on(UNIX_DEBUG, ctrl))
pam_syslog(pamh, LOG_DEBUG, "username [%s] obtained",
user);
} else {
if (on(UNIX_DEBUG, ctrl))
pam_syslog(pamh, LOG_DEBUG,
"password - could not identify user");
return retval;
}
D(("Got username of %s", user));
/*
* Before we do anything else, check to make sure that the user's
* info is in one of the databases we can modify from this module,
* which currently is 'files' and 'nis'. We have to do this because
* getpwnam() doesn't tell you *where* the information it gives you
* came from, nor should it. That's our job.
*/
if (_unix_comesfromsource(pamh, user, 1, on(UNIX_NIS, ctrl)) == 0) {
pam_syslog(pamh, LOG_DEBUG,
"user \"%s\" does not exist in /etc/passwd%s",
user, on(UNIX_NIS, ctrl) ? " or NIS" : "");
return PAM_USER_UNKNOWN;
} else {
struct passwd *pwd;
_unix_getpwnam(pamh, user, 1, 1, &pwd);
if (pwd == NULL) {
pam_syslog(pamh, LOG_DEBUG,
"user \"%s\" has corrupted passwd entry",
user);
return PAM_USER_UNKNOWN;
}
}
/*
* This is not an AUTH module!
*/
if (on(UNIX__NONULL, ctrl))
set(UNIX__NULLOK, ctrl);
if (on(UNIX__PRELIM, ctrl)) {
/*
* obtain and verify the current password (OLDAUTHTOK) for
* the user.
*/
char *Announce;
D(("prelim check"));
if (_unix_blankpasswd(pamh, ctrl, user)) {
return PAM_SUCCESS;
} else if (off(UNIX__IAMROOT, ctrl)) {
/* instruct user what is happening */
if (asprintf(&Announce, _("Changing password for %s."),
user) < 0) {
pam_syslog(pamh, LOG_CRIT,
"password - out of memory");
return PAM_BUF_ERR;
}
lctrl = ctrl;
set(UNIX__OLD_PASSWD, lctrl);
retval = _unix_read_password(pamh, lctrl
,Announce
,_("(current) UNIX password: "******"password - (old) token not obtained");
return retval;
}
/* verify that this is the password for this user */
retval = _unix_verify_password(pamh, user, pass_old, ctrl);
} else {
D(("process run by root so do nothing this time around"));
pass_old = NULL;
retval = PAM_SUCCESS; /* root doesn't have too */
}
if (retval != PAM_SUCCESS) {
D(("Authentication failed"));
pass_old = NULL;
return retval;
}
retval = pam_set_item(pamh, PAM_OLDAUTHTOK, (const void *) pass_old);
pass_old = NULL;
if (retval != PAM_SUCCESS) {
pam_syslog(pamh, LOG_CRIT,
"failed to set PAM_OLDAUTHTOK");
}
retval = _unix_verify_shadow(pamh,user, ctrl);
if (retval == PAM_AUTHTOK_ERR) {
if (off(UNIX__IAMROOT, ctrl))
_make_remark(pamh, ctrl, PAM_ERROR_MSG,
_("You must wait longer to change your password"));
else
retval = PAM_SUCCESS;
}
} else if (on(UNIX__UPDATE, ctrl)) {
/*
* tpass is used below to store the _pam_md() return; it
* should be _pam_delete()'d.
*/
char *tpass = NULL;
int retry = 0;
/*
* obtain the proposed password
*/
D(("do update"));
/*
* 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(UNIX_NOT_SET_PASS, ctrl)) {
retval = pam_get_item(pamh, PAM_OLDAUTHTOK
,&pass_old);
} else {
retval = pam_get_data(pamh, _UNIX_OLD_AUTHTOK
,&pass_old);
if (retval == PAM_NO_MODULE_DATA) {
retval = PAM_SUCCESS;
pass_old = NULL;
}
}
D(("pass_old [%s]", pass_old));
if (retval != PAM_SUCCESS) {
pam_syslog(pamh, LOG_NOTICE, "user not authenticated");
return retval;
}
D(("get new password now"));
lctrl = ctrl;
if (on(UNIX_USE_AUTHTOK, lctrl)) {
set(UNIX_USE_FIRST_PASS, lctrl);
}
retry = 0;
retval = PAM_AUTHTOK_ERR;
while ((retval != PAM_SUCCESS) && (retry++ < MAX_PASSWD_TRIES)) {
/*
* use_authtok is to force the use of a previously entered
* password -- needed for pluggable password strength checking
*/
retval = _unix_read_password(pamh, lctrl
,NULL
,_("Enter new UNIX password: "******"Retype new UNIX password: "******"password - new password not obtained");
}
pass_old = NULL; /* tidy up */
return retval;
}
D(("returned to _unix_chauthtok"));
/*
* 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 (*(const char *)pass_new == '\0') { /* "\0" password = NULL */
pass_new = NULL;
}
retval = _pam_unix_approve_pass(pamh, ctrl, pass_old,
pass_new, pass_min_len);
if (retval != PAM_SUCCESS && off(UNIX_NOT_SET_PASS, ctrl)) {
pam_set_item(pamh, PAM_AUTHTOK, NULL);
}
}
if (retval != PAM_SUCCESS) {
pam_syslog(pamh, LOG_NOTICE,
"new password not acceptable");
pass_new = pass_old = NULL; /* tidy up */
return retval;
}
if (lock_pwdf() != PAM_SUCCESS) {
return PAM_AUTHTOK_LOCK_BUSY;
}
if (pass_old) {
retval = _unix_verify_password(pamh, user, pass_old, ctrl);
if (retval != PAM_SUCCESS) {
pam_syslog(pamh, LOG_NOTICE, "user password changed by another process");
unlock_pwdf();
return retval;
}
}
retval = _unix_verify_shadow(pamh, user, ctrl);
if (retval != PAM_SUCCESS) {
pam_syslog(pamh, LOG_NOTICE, "user shadow entry expired");
unlock_pwdf();
return retval;
}
retval = _pam_unix_approve_pass(pamh, ctrl, pass_old, pass_new,
pass_min_len);
if (retval != PAM_SUCCESS) {
pam_syslog(pamh, LOG_NOTICE,
"new password not acceptable 2");
pass_new = pass_old = NULL; /* tidy up */
unlock_pwdf();
return retval;
}
/*
* By reaching here we have approved the passwords and must now
* rebuild the password database file.
*/
/*
* First we encrypt the new password.
*/
tpass = create_password_hash(pamh, pass_new, ctrl, rounds);
if (tpass == NULL) {
pam_syslog(pamh, LOG_CRIT,
"out of memory for password");
pass_new = pass_old = NULL; /* tidy up */
unlock_pwdf();
return PAM_BUF_ERR;
}
D(("password processed"));
/* update the password database(s) -- race conditions..? */
retval = _do_setpass(pamh, user, pass_old, tpass, ctrl,
remember);
/* _do_setpass has called unlock_pwdf for us */
_pam_delete(tpass);
pass_old = pass_new = NULL;
} else { /* something has broken with the module */
pam_syslog(pamh, LOG_ALERT,
"password received unknown request");
retval = PAM_ABORT;
}
D(("retval was %d", retval));
return retval;
}