.\"     Title: pam_sm_chauthtok
.\"    Author: 
.\" Generator: DocBook XSL Stylesheets v1.70.1 <http://docbook.sf.net/>
.\"      Date: 06/27/2006
.\"    Manual: Linux\-PAM Manual
.\"    Source: Linux\-PAM Manual
.\"
.TH "PAM_SM_CHAUTHTOK" "3" "06/27/2006" "Linux\-PAM Manual" "Linux\-PAM Manual"
.\" disable hyphenation
.nh
.\" disable justification (adjust text to left margin only)
.ad l
.SH "NAME"
pam_sm_chauthtok \- PAM service function for authentication token management
.SH "SYNOPSIS"
.sp
.ft B
.nf
#define PAM_SM_PASSWORD
.fi
.ft
.sp
.ft B
.nf
#include <security/pam_modules.h>
.fi
.ft
.HP 32
.BI "PAM_EXTERN int pam_sm_chauthtok(pam_handle_t\ *" "pamh" ", int\ " "flags" ", int\ " "argc" ", const\ char\ **" "argv" ");"
.SH "DESCRIPTION"
.PP
The
\fBpam_sm_chauthtok\fR
function is the service module's implementation of the
\fBpam_chauthtok\fR(3)
interface.
.PP
This function is used to (re\-)set the authentication token of the user.
.PP
Valid flags, which may be logically OR'd with
\fIPAM_SILENT\fR, are:
.TP 3n
PAM_SILENT
Do not emit any messages.
.TP 3n
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
\fImust\fR
be combined with one of the following two flags. Note, however, the following two options are
\fImutually exclusive\fR.
.TP 3n
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
\fBPAM_TRY_AGAIN\fR, this information will be passed back to the application.
.TP 3n
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
\fBPAM_CHANGE_EXPIRED_AUTHTOK\fR, the token is only changed if it has actually expired.
.PP
The PAM library calls this function twice in succession. The first time with
\fBPAM_PRELIM_CHECK\fR
and then, if the module does not return
\fBPAM_TRY_AGAIN\fR, subsequently with
\fBPAM_UPDATE_AUTHTOK\fR. It is only on the second call that the authorization token is (possibly) changed.
.SH "RETURN VALUES"
.TP 3n
PAM_AUTHTOK_ERR
The module was unable to obtain the new authentication token.
.TP 3n
PAM_AUTHTOK_RECOVERY_ERR
The module was unable to obtain the old authentication token.
.TP 3n
PAM_AUTHTOK_LOCK_BUSY
Cannot change the authentication token since it is currently locked.
.TP 3n
PAM_AUTHTOK_DISABLE_AGING
Authentication token aging has been disabled.
.TP 3n
PAM_PERM_DENIED
Permission denied.
.TP 3n
PAM_TRY_AGAIN
Preliminary check was unsuccessful. Signals an immediate return to the application is desired.
.TP 3n
PAM_SUCCESS
The authentication token was successfully updated.
.TP 3n
PAM_USER_UNKNOWN
User unknown to password service.
.SH "SEE ALSO"
.PP

\fBpam\fR(3),
\fBpam_chauthtok\fR(3),
\fBpam_sm_chauthtok\fR(3),
\fBpam_strerror\fR(3),
\fBPAM\fR(8)