-.\" $OpenBSD: ssh-keysign.8,v 1.1 2002/05/25 08:16:59 markus Exp $
+.\" $OpenBSD: ssh-keysign.8,v 1.8 2006/02/24 20:22:16 jmc Exp $
.\"
.\" Copyright (c) 2002 Markus Friedl. All rights reserved.
.\"
.Os
.Sh NAME
.Nm ssh-keysign
-.Nd ssh helper program for hostbased authentication
+.Nd ssh helper program for host-based authentication
.Sh SYNOPSIS
-.Nm ssh-keysign
+.Nm
.Sh DESCRIPTION
.Nm
is used by
.Xr ssh 1
-to access the local host keys during hostbased authentication with
-SSH protocol version 2.
-Since the host keys are readable only by root
+to access the local host keys and generate the digital signature
+required during host-based authentication with SSH protocol version 2.
+.Pp
.Nm
-must be setuid root.
+is disabled by default and can only be enabled in the
+global client configuration file
+.Pa /etc/ssh/ssh_config
+by setting
+.Cm EnableSSHKeysign
+to
+.Dq yes .
+.Pp
.Nm
is not intended to be invoked by the user, but from
.Xr ssh 1 .
.Xr ssh 1
and
.Xr sshd 8
-for more information about hostbased authentication.
+for more information about host-based authentication.
+.Sh FILES
+.Bl -tag -width Ds
+.It Pa /etc/ssh/ssh_config
+Controls whether
+.Nm
+is enabled.
+.It Pa /etc/ssh/ssh_host_dsa_key, /etc/ssh/ssh_host_rsa_key
+These files contain the private parts of the host keys used to
+generate the digital signature.
+They should be owned by root, readable only by root, and not
+accessible to others.
+Since they are readable only by root,
+.Nm
+must be set-uid root if host-based authentication is used.
+.El
.Sh SEE ALSO
.Xr ssh 1 ,
+.Xr ssh-keygen 1 ,
+.Xr ssh_config 5 ,
.Xr sshd 8
-.Sh AUTHORS
-Markus Friedl <markus@openbsd.org>
.Sh HISTORY
.Nm
first appeared in
.Ox 3.2 .
+.Sh AUTHORS
+.An Markus Friedl Aq markus@openbsd.org