PAM_SM_CHAUTHTOK(3)           Linux-PAM Manual           PAM_SM_CHAUTHTOK(3)

NAME         top

       pam_sm_chauthtok - PAM service function for authentication token

SYNOPSIS         top

       #define PAM_SM_PASSWORD

       #include <security/pam_modules.h>

       int pam_sm_chauthtok(pam_handle_t *pamh, int flags, int argc,
                            const char **argv);

DESCRIPTION         top

       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

       Valid flags, which may be logically OR'd with PAM_SILENT, are:

           Do not emit any messages.

           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.

           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

           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.

           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         top

           The module was unable to obtain the new authentication token.

           The module was unable to obtain the old authentication token.

           Cannot change the authentication token since it is currently

           Authentication token aging has been disabled.

           Permission denied.

           Preliminary check was unsuccessful. Signals an immediate return
           to the application is desired.

           The authentication token was successfully updated.

           User unknown to password service.

SEE ALSO         top

       pam(3), pam_chauthtok(3), pam_sm_chauthtok(3), pam_strerror(3),

COLOPHON         top

       This page is part of the linux-pam (Pluggable Authentication Modules
       for Linux) project.  Information about the project can be found at 
       ⟨⟩.  If you have a bug report for
       this manual page, see ⟨⟩.
       This page was obtained from the tarball Linux-PAM-1.3.0.tar.gz
       fetched from ⟨⟩ on 2017-03-13.  If
       you discover any rendering problems in this HTML version of the page,
       or you believe there is a better or more up-to-date source for the
       page, or you have corrections or improvements to the information in
       this COLOPHON (which is not part of the original manual page), send a
       mail to

Linux-PAM Manual                 04/01/2016              PAM_SM_CHAUTHTOK(3)