.\" $OpenBSD: login_krb4.8,v 1.7 2001/11/13 14:06:10 mpech Exp $
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.\" Copyright (c) 2000 Todd C. Miller <Todd.Miller@courtesan.com>
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.Dd December 11, 2000
.Dt LOGIN_KERBEROS 8
.Os
.Sh NAME
.Nm login_krb4
.Nd provide KerberosIV authentication type
.Sh SYNOPSIS
.Nm
.Op Fl s Ar service
.Op Fl v Ar lastchance=yes|no
.Ar user
.Op Ar class
.Sh DESCRIPTION
The
.Nm
utility implements the KerberosIV authentication mechanism.
It is called by
.Xr login 1 ,
.Xr su 1 ,
.Xr ftpd 8 ,
and others to authenticate the
.Ar user
with KerberosIV.
.Pp
The
.Ar user
argument is the user's name to be authenticated.
.Pp
The
.Ar service
argument specifies which protocol to use with the
invoking program.
The allowed protocols are
.Em login ,
.Em challenge ,
and
.Em response .
(The
.Em challenge
protocol is silently ignored but will report success as KerberosIV
authentication is not challenge-response based).
.Pp
If the
.Ar lastchance
argument is specified and is equal to
.Dq yes ,
then if the user's password has expired, and it has not been
expired longer than
.Dq password-dead
seconds (see
.Xr login.conf 5 ) ,
the user will be able to log in one last time to change the password.
.Pp
.Nm
will prompt the user for a password and report back to the
invoking program whether or not the authentication was
successful.
.Sh SEE ALSO
.Xr login 1 ,
.Xr passwd 1 ,
.Xr su 1 ,
.Xr login.conf 5 ,
.Xr ftpd 8 ,
.Xr login_krb4-or-pwd 8 ,
.Xr kerberos 1