To be correctly initialized, PAM_SM_PASSWORD
must be
#define
'd prior to including <security/pam_modules.h>
.
This will ensure that the prototype for a static module is properly
declared.
PAM_EXTERN int pam_sm_chauthtok(pam_handle_t *pamh, int flags, int
argc, const char **argv);
This function is used to (re-)set the authentication token of the
user. A valid flag, which may be logically OR'd with PAM_SILENT
,
can be built from the following list,
PAM_CHANGE_EXPIRED_AUTHTOK
This argument indicates to the module that the users authentication token (password) should only be changed if it has expired. This flag is optional and must be combined with one of the following two flags. Note, however, the following two options are mutually exclusive.
PAM_PRELIM_CHECK
This indicates that the modules are being probed as to their
ready status for altering the user's authentication token. If the
module requires access to another system over some network it should
attempt to verify it can connect to this system on receiving this
flag. If a module cannot establish it is ready to update the user's
authentication token it should return PAM_TRY_AGAIN
, this
information will be passed back to the application.
PAM_UPDATE_AUTHTOK
This informs the module that this is the call it should change
the authorization tokens. If the flag is logically OR'd with
PAM_CHANGE_EXPIRED_AUTHTOK
, the token is only changed if it has
actually expired.
Note, the Linux-PAM library calls this function twice in
succession. The first time with PAM_PRELIM_CHECK
and then, if the
module does not return PAM_TRY_AGAIN
, subsequently with
PAM_UPDATE_AUTHTOK
. It is only on the second call that the
authorization token is (possibly) changed.
PAM_SUCCESS
is the only successful return value, valid
error-returns are:
PAM_AUTHTOK_ERR
The module was unable to obtain the new authentication token.
PAM_AUTHTOK_RECOVERY_ERR
The module was unable to obtain the old authentication token.
PAM_AUTHTOK_LOCK_BUSY
Cannot change the authentication token since it is currently locked.
PAM_AUTHTOK_DISABLE_AGING
Authentication token aging has been disabled.
PAM_PERM_DENIED
Permission denied.
PAM_TRY_AGAIN
Preliminary check was unsuccessful. Signals an immediate return to the application is desired.
PAM_USER_UNKNOWN
The user is not known to the authentication token changing service.