Password Management (Cont.)

Valid return values:
PAM_SUCCESS - the token was updated successfully.
PAM_AUTHTOK_RECOVERY_ERR - the module could not obtain the old authentication token.
PAM_AUTHTOK_LOCK_BUSY - the authentication token is currently locked and cannot be chaned.
PAM_AUTHTOK_DISABLE_AGING - authentication token aging has been disabled.
PAM_PERM_DENIED - permission denied.
PAM_TRY_AGAIN - some preliminary check has failed. the PAM library should immediatly return control to the application.
PAM_USER_UNKNOWN - the module's authenticatin service does not know this user.