NAME
pam_sm_chauthtok - PAM service function for authentication token managementSYNOPSIS
#include <security/pam_modules.h>
int
pam_sm_chauthtok(pam_handle_t *pamh,
int flags, int argc,
const char **argv);
DESCRIPTION
The pam_sm_chauthtok function is the service module's implementation of the pam_chauthtok(3) interface. This function is used to (re-)set the authentication token of the user. Valid flags, which may be logically OR'd with PAM_SILENT, are: PAM_SILENTDo not emit any messages.
PAM_CHANGE_EXPIRED_AUTHTOK
This argument indicates to the module that the
user's 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.
If the control value sufficient is used in the password stack, the
PAM_PRELIM_CHECK section of the modules following that control value is
not always executed.
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.
The 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.
RETURN VALUES
PAM_AUTHTOK_ERRThe 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_SUCCESS
The authentication token was successfully
updated.
PAM_USER_UNKNOWN
User unknown to password service.
SEE ALSO
pam(3), pam_chauthtok(3), , pam_strerror(3), PAM(8)09/03/2021 | Linux-PAM Manual |