.\" (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 1.104 2009/04/17 19:40:17 stevesk Exp $
+.\" $OpenBSD: sshd_config.5,v 1.116 2010/01/09 23:04:13 dtucker Exp $
.Dd $Mdocdate$
.Dt SSHD_CONFIG 5
.Os
This option is only available for protocol version 2.
By default, no banner is displayed.
.It Cm ChallengeResponseAuthentication
-Specifies whether challenge-response authentication is allowed.
-All authentication styles from
-.Xr login.conf 5
-are supported.
+Specifies whether challenge-response authentication is allowed (e.g. via
+PAM or though authentication styles supported in
+.Xr login.conf 5 )
The default is
.Dq yes .
.It Cm ChrootDirectory
-Specifies a path to
+Specifies the pathname of a directory to
.Xr chroot 2
to after authentication.
-This path, and all its components, must be root-owned directories that are
+All components of the pathname must be root-owned directories that are
not writable by any other user or group.
+After the chroot,
+.Xr sshd 8
+changes the working directory to the user's home directory.
.Pp
-The path may contain the following tokens that are expanded at runtime once
+The pathname may contain the following tokens that are expanded at runtime once
the connecting user has been authenticated: %% is replaced by a literal '%',
%h is replaced by the home directory of the user being authenticated, and
%u is replaced by the username of that user.
.Xr tty 4
devices.
For file transfer sessions using
-.Dq sftp
-which do not use logging,
+.Dq sftp ,
no additional configuration of the environment is necessary if the
-in-process sftp server is used (see
-.Cm Subsystem
-for details).
-sftp sessions which do use logging require
+in-process sftp server is used,
+though sessions which use logging do require
.Pa /dev/log
inside the chroot directory (see
.Xr sftp-server 8
.Cm PermitEmptyPasswords ,
.Cm PermitOpen ,
.Cm PermitRootLogin ,
+.Cm PubkeyAuthentication ,
.Cm RhostsRSAAuthentication ,
.Cm RSAAuthentication ,
.Cm X11DisplayOffset ,
.Sq 2 .
Multiple versions must be comma-separated.
The default is
-.Dq 2,1 .
+.Sq 2 .
Note that the order of the protocol list does not indicate preference,
because the client selects among multiple protocol versions offered
by the server.
directory or files world-writable.
The default is
.Dq yes .
+Note that this does not apply to
+.Cm ChrootDirectory ,
+whose permissions and ownership are checked unconditionally.
.It Cm Subsystem
Configures an external subsystem (e.g. file transfer daemon).
Arguments should be a subsystem name and a command (with optional arguments)