.\" $OpenBSD: login_skey.8,v 1.5 2002/08/28 14:06:47 mpech Exp $
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.\" Copyright (c) 2000, 2002 Todd C. Miller <Todd.Miller@courtesan.com>
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.Dd July 14, 2002
.Dt LOGIN_SKEY 8
.Os
.Sh NAME
.Nm login_skey
.Nd provide S/Key authentication type
.Sh SYNOPSIS
.Nm login_skey
.Op Fl s Ar service
.Ar user
.Op Ar class
.Sh DESCRIPTION
The
.Nm
utility is called by
.Xr login 1 ,
.Xr su 1 ,
.Xr ftpd 8 ,
and others to authenticate the
.Ar user
with S/Key authentication.
.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 default protocol is
.Em login .
.Pp
The
.Ar user
argument is the login name of the user to be authenticated.
.Pp
The
.Ar class
argument is not used.
.Pp
.Nm
will look up
.Ar user
in the S/Key database and, depending on the desired protocol,
will do one of three things:
.Bl -tag -width challenge
.It login
Present
.Ar user
with an S/Key challenge, accept a response and report back to the
invoking program whether or not the authentication was successful.
.It challenge
Return the current S/Key challenge for
.Ar user .
.It response
Report back to the invoking program whether or not the specified
response matches the current S/Key challenge for
.Ar user .
.El
.Pp
If
.Ar user
does not have an entry in the S/Key database, a fake challenge will
be generated by the S/Key library.
.Sh FILES
.Bl -tag -width /etc/skey
.It Pa /etc/skey
directory containing user entries for S/Key
.El
.Sh SEE ALSO
.Xr login 1 ,
.Xr skey 1 ,
.Xr skeyinfo 1 ,
.Xr skeyinit 1 ,
.Xr login.conf 5 ,
.Xr ftpd 8