.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
.\"
-.\" $OpenBSD: sshd_config.5,v 1.17 2003/05/20 12:09:32 jmc Exp $
+.\" $OpenBSD: sshd_config.5,v 1.25 2003/09/01 09:50:04 markus Exp $
.Dd September 25, 1999
.Dt SSHD_CONFIG 5
.Os
keywords and their meanings are as follows (note that
keywords are case-insensitive and arguments are case-sensitive):
.Bl -tag -width Ds
-.It Cm AFSTokenPassing
-Specifies whether an AFS token may be forwarded to the server.
-Default is
-.Dq no .
.It Cm AllowGroups
This keyword can be followed by a list of group name patterns, separated
by spaces.
.Pp
.Bd -literal
``aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,arcfour,
- aes192-cbc,aes256-cbc''
+ aes192-cbc,aes256-cbc,aes128-ctr,aes192-ctr,aes256-ctr''
.Ed
.It Cm ClientAliveInterval
Sets a timeout interval in seconds after which if no data has been received
.Dq no .
The default is
.Dq no .
+.It Cm GSSAPIAuthentication
+Specifies whether user authentication based on GSSAPI is allowed.
+The default is
+.Dq no .
+Note that this option applies to protocol version 2 only.
+.It Cm GSSAPICleanupCredentials
+Specifies whether to automatically destroy the user's credentials cache
+on logout.
+The default is
+.Dq yes .
+Note that this option applies to protocol version 2 only.
.It Cm HostbasedAuthentication
Specifies whether rhosts or /etc/hosts.equiv authentication together
with successful public key client host authentication is allowed
and
.Pa .shosts
files will not be used in
-.Cm RhostsAuthentication ,
.Cm RhostsRSAAuthentication
or
.Cm HostbasedAuthentication .
To disable keepalives, the value should be set to
.Dq no .
.It Cm KerberosAuthentication
-Specifies whether Kerberos authentication is allowed.
-This can be in the form of a Kerberos ticket, or if
+Specifies whether the password provided by the user for
.Cm PasswordAuthentication
-is yes, the password provided by the user will be validated through
-the Kerberos KDC.
+will be validated through the Kerberos KDC.
To use this option, the server needs a
Kerberos servtab which allows the verification of the KDC's identity.
Default is
.Pa /etc/passwd .
Default is
.Dq yes .
-.It Cm KerberosTgtPassing
-Specifies whether a Kerberos TGT may be forwarded to the server.
-Default is
-.Dq no ,
-as this only works when the Kerberos KDC is actually an AFS kaserver.
.It Cm KerberosTicketCleanup
Specifies whether to automatically destroy the user's ticket cache
file on logout.
The default is
.Dq yes .
Note that this option applies to protocol version 2 only.
-.It Cm RhostsAuthentication
-Specifies whether authentication using rhosts or /etc/hosts.equiv
-files is sufficient.
-Normally, this method should not be permitted because it is insecure.
.Cm RhostsRSAAuthentication
should be used
instead, because it performs RSA-based host authentication in addition
The possible values are: DAEMON, USER, AUTH, LOCAL0, LOCAL1, LOCAL2,
LOCAL3, LOCAL4, LOCAL5, LOCAL6, LOCAL7.
The default is AUTH.
+.It Cm UseDNS
+Specifies whether
+.Nm sshd
+should lookup the remote host name and check that
+the resolved host name for the remote IP address maps back to the
+very same IP address.
+The default is
+.Dq yes .
.It Cm UseLogin
Specifies whether
.Xr login 1
escalation by containing any corruption within the unprivileged processes.
The default is
.Dq yes .
-.It Cm VerifyReverseMapping
-Specifies whether
-.Nm sshd
-should try to verify the remote host name and check that
-the resolved host name for the remote IP address maps back to the
-very same IP address.
-The default is
-.Dq no .
.It Cm X11DisplayOffset
Specifies the first display number available for
.Nm sshd Ns 's
forwarding (see the warnings for
.Cm ForwardX11
in
-.Xr ssh_config 5 ).
+.Xr ssh_config 5 ) .
A system administrator may have a stance in which they want to
protect clients that may expose themselves to attack by unwittingly
requesting X11 forwarding, which can warrant a
.Pa /usr/X11R6/bin/xauth .
.El
.Ss Time Formats
-.Pp
.Nm sshd
command-line arguments and configuration file options that specify time
may be expressed using a sequence of the form:
This file should be writable by root only, but it is recommended
(though not necessary) that it be world-readable.
.El
+.Sh SEE ALSO
+.Xr sshd 8
.Sh AUTHORS
OpenSSH is a derivative of the original and free
ssh 1.2.12 release by Tatu Ylonen.
protocol versions 1.5 and 2.0.
Niels Provos and Markus Friedl contributed support
for privilege separation.
-.Sh SEE ALSO
-.Xr sshd 8