diff options
Diffstat (limited to 'crypto/openssh/sshd.8')
-rw-r--r-- | crypto/openssh/sshd.8 | 55 |
1 files changed, 44 insertions, 11 deletions
diff --git a/crypto/openssh/sshd.8 b/crypto/openssh/sshd.8 index 517ecbd..31b822e 100644 --- a/crypto/openssh/sshd.8 +++ b/crypto/openssh/sshd.8 @@ -33,9 +33,9 @@ .\" (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.8,v 1.280 2015/07/03 03:49:45 djm Exp $ +.\" $OpenBSD: sshd.8,v 1.284 2016/02/17 07:38:19 jmc Exp $ .\" $FreeBSD$ -.Dd $Mdocdate: July 3 2015 $ +.Dd $Mdocdate: February 17 2016 $ .Dt SSHD 8 .Os .Sh NAME @@ -276,14 +276,12 @@ though this can be changed via the .Cm Protocol option in .Xr sshd_config 5 . -Protocol 2 supports DSA, ECDSA, Ed25519 and RSA keys; -protocol 1 only supports RSA keys. -For both protocols, -each host has a host-specific key, -normally 2048 bits, -used to identify the host. +Protocol 1 should not be used +and is only offered to support legacy devices. .Pp -Forward security for protocol 1 is provided through +Each host has a host-specific key, +used to identify the host. +Partial forward security for protocol 1 is provided through an additional server key, normally 1024 bits, generated when the server starts. @@ -473,7 +471,7 @@ does not exist either, xauth is used to add the cookie. .Cm AuthorizedKeysFile specifies the files containing public keys for public key authentication; -if none is specified, the default is +if this option is not specified, the default is .Pa ~/.ssh/authorized_keys and .Pa ~/.ssh/authorized_keys2 . @@ -525,6 +523,10 @@ No spaces are permitted, except within double quotes. The following option specifications are supported (note that option keywords are case-insensitive): .Bl -tag -width Ds +.It Cm agent-forwarding +Enable authentication agent forwarding previously disabled by the +.Cm restrict +option. .It Cm cert-authority Specifies that the listed key is a certification authority (CA) that is trusted to validate signed certificates for user authentication. @@ -619,6 +621,9 @@ they must be literal domains or addresses. A port specification of .Cm * matches any port. +.It Cm port-forwarding +Enable port forwarding previously disabled by the +.Cm restrict .It Cm principals="principals" On a .Cm cert-authority @@ -630,12 +635,33 @@ This option is ignored for keys that are not marked as trusted certificate signers using the .Cm cert-authority option. +.It Cm pty +Permits tty allocation previously disabled by the +.Cm restrict +option. +.It Cm restrict +Enable all restrictions, i.e. disable port, agent and X11 forwarding, +as well as disabling PTY allocation +and execution of +.Pa ~/.ssh/rc . +If any future restriction capabilities are added to authorized_keys files +they will be included in this set. .It Cm tunnel="n" Force a .Xr tun 4 device on the server. Without this option, the next available device will be used if the client requests a tunnel. +.It Cm user-rc +Enables execution of +.Pa ~/.ssh/rc +previously disabled by the +.Cm restrict +option. +.It Cm X11-forwarding +Permits X11 forwarding previously disabled by the +.Cm restrict +option. .El .Pp An example authorized_keys file: @@ -650,6 +676,10 @@ permitopen="192.0.2.1:80",permitopen="192.0.2.2:25" ssh-dss AAAAB5...21S== tunnel="0",command="sh /etc/netstart tun0" ssh-rsa AAAA...== jane@example.net +restrict,command="uptime" ssh-rsa AAAA1C8...32Tv== +user@example.net +restrict,pty,command="nethack" ssh-rsa AAAA1f8...IrrC5== +user@example.net .Ed .Sh SSH_KNOWN_HOSTS FILE FORMAT The @@ -865,9 +895,12 @@ This file is for host-based authentication (see It should only be writable by root. .Pp .It Pa /etc/moduli -Contains Diffie-Hellman groups used for the "Diffie-Hellman Group Exchange". +Contains Diffie-Hellman groups used for the "Diffie-Hellman Group Exchange" +key exchange method. The file format is described in .Xr moduli 5 . +If no usable groups are found in this file then fixed internal groups will +be used. .Pp .It Pa /etc/motd See |