Various Debian-specific configuration changes

ssh: Enable ForwardX11Trusted, returning to earlier semantics which cause
fewer problems with existing setups (http://bugs.debian.org/237021).

ssh: Set 'SendEnv LANG LC_*' by default (http://bugs.debian.org/264024).

ssh: Enable HashKnownHosts by default to try to limit the spread of ssh
worms.

ssh: Enable GSSAPIAuthentication and disable GSSAPIDelegateCredentials by
default.

Document all of this, along with several sshd defaults set in
debian/openssh-server.postinst.

Author: Russ Allbery <rra@debian.org>
Forwarded: not-needed
Last-Update: 2015-12-07

Patch-Name: debian-config.patch

1 files changed, 21 insertions, 0 deletions

diff --git a/ssh.1 b/ssh.1
index 05b7f107b..649d6c303 100644
--- a/ssh.1
+++ b/ssh.1
@@ -755,6 +755,16 @@ directive in
 .Xr ssh_config 5
 for more information.
 .Pp
+(Debian-specific: X11 forwarding is not subjected to X11 SECURITY extension
+restrictions by default, because too many programs currently crash in this
+mode.
+Set the
+.Cm ForwardX11Trusted
+option to
+.Dq no
+to restore the upstream behaviour.
+This may change in future depending on client-side improvements.)
+.Pp
 .It Fl x
 Disables X11 forwarding.
 .Pp
@@ -763,6 +773,17 @@ Enables trusted X11 forwarding.
 Trusted X11 forwardings are not subjected to the X11 SECURITY extension
 controls.
 .Pp
+(Debian-specific: This option does nothing in the default configuration: it
+is equivalent to
+.Dq Cm ForwardX11Trusted No yes ,
+which is the default as described above.
+Set the
+.Cm ForwardX11Trusted
+option to
+.Dq no
+to restore the upstream behaviour.
+This may change in future depending on client-side improvements.)
+.Pp
 .It Fl y
 Send log information using the
 .Xr syslog 3