.\"-
.\" Copyright (c) 2001-2003 Networks Associates Technology, Inc.
.\" Copyright (c) 2004-2011 Dag-Erling Smørgrav
.\" All rights reserved.
.\"
.\" This software was developed for the FreeBSD Project by ThinkSec AS and
.\" Network Associates Laboratories, the Security Research Division of
.\" Network Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035
.\" ("CBOSS"), as part of the DARPA CHATS research program.
.\"
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.\"    notice, this list of conditions and the following disclaimer in the
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.\" $Id$
.\"
.Dd December 18, 2011
.Dt OPENPAM_SUBST 3
.Os
.Sh NAME
.Nm openpam_subst
.Nd substitute PAM item values in a string
.Sh LIBRARY
.Lb libpam
.Sh SYNOPSIS
.In sys/types.h
.In security/pam_appl.h
.In security/openpam.h
.Ft "int"
.Fn openpam_subst "const pam_handle_t *pamh" "char *buf" "size_t *bufsize" "const char *template"
.Sh DESCRIPTION
The
.Nm
function expands a string, substituting PAM item
values for all occurrences of specific substitution codes.
The
.Fa template
argument points to the initial string.
The result is stored in the buffer pointed to by the
.Fa buf
argument; the
.Fa bufsize
argument specifies the size of that buffer.
The actual size of the resulting string, including the terminating NUL
character, is stored in the location pointed to by the
.Fa bufsize
argument.
.Pp
If
.Fa buf
is NULL, or if the buffer is too small to hold the expanded
string,
.Fa bufsize
is updated to reflect the amount of space required to
hold the entire string, and
.Nm
returns
.Dv PAM_TRY_AGAIN .
.Pp
If
.Nm
fails for any other reason, the
.Fa bufsize
argument is
untouched, but part of the buffer may still have been overwritten.
.Pp
Substitution codes are introduced by a percent character and correspond
to PAM items:
.Bl -tag -width 18n
.It \&%H
Replaced by the current value of the
.Dv PAM_RHOST
item.
.It \&%h
Replaced by the current value of the
.Dv PAM_HOST
item.
.It \&%s
Replaced by the current value of the
.Dv PAM_SERVICE
item.
.It \&%t
Replaced by the current value of the
.Dv PAM_TTY
item.
.It \&%U
Replaced by the current value of the
.Dv PAM_RUSER
item.
.It \&%u
Replaced by the current value of the
.Dv PAM_USER
item.
.El
.Pp
.Sh RETURN VALUES
The
.Nm
function returns one of the following values:
.Bl -tag -width 18n
.It Bq Er PAM_SYSTEM_ERR
System error.
.It Bq Er PAM_TRY_AGAIN
Try again.
.El
.Sh SEE ALSO
.Xr pam 3 ,
.Xr pam_get_authtok 3 ,
.Xr pam_get_item 3 ,
.Xr pam_get_user 3 ,
.Xr pam_strerror 3
.Sh STANDARDS
The
.Nm
function is an OpenPAM extension.
.Sh AUTHORS
The
.Nm
function and this manual page were developed for the
.Fx
Project by
.An Dag-Erling Sm\(/orgrav Aq des@FreeBSD.org .