[gentoo-user] ssh -X problem [no help sofar on ssh group]

[Harry Putnam]

This properly belongs on the ssh group, but posting there has not gotten
any responses... and the list is quite slow to boot.

I like using ssh -X to other lan remotes but with new versions of openssh
or perhaps the configs, it only works 1 way.

I can `ssh  -X' to the gentoo host from a debian host but not the other
way round.

Two different versions of openssh appear to be involved.  But not sure
how different they are.

RHOST=a debian HOST
LHOST= Gentoo HOST

ssh -vN $RHOST 2>&1|grep "remote software version"

  [...] OpenSSH_6.7p1 Debian-3

ssh -vN $LHOST 2>&1|grep "remote software version"

  [...] OpenSSH_6.7p1-hpn14v5


One thing I tried to do was to copy the RHOST sshd_config and ssh_config to
LHOST.  Restart and try again... there were a few incompatible bits in
the files so after commenting a few out until no config errors.

However ssh -X still displayed the error and would NOT work when:
  ssh -X RHOST from LHOST
({Note that plain ssh LHOST or RHOST works in any direction}

Error outut with ssh -X $RHOST "xterm"

,----
| Warning: untrusted X11 forwarding setup failed: xauth key data not generated
| Warning: No xauth data; using fake authentication data for X11 forwarding.
| Invalid MIT-MAGIC-COOKIE-1 keyxterm: Xt error: Can't open display: localhost:10.0
`----

[Full Error output with ssh -vv -X is very lengthy so is attached at the end]

I'm not seeing how to debug this further.  So going back to the stock
version of sshd_config ssh_config on gentoo with two changes:

commented out this line:
 PasswordAuthentication no

added this:
 X11Forwarding yes

-------       -------       ---=---       -------       ------- 
Full sshd_config on LHOST: sudo grep ^[^#] /etc/ssh/sshd_config
-------       -------       ---=---       -------       ------- 
  UsePAM yes
  X11Forwarding yes
  PrintMotd no
  PrintLastLog no
  UsePrivilegeSeparation sandbox		# Default for new installations.
  Subsystem	sftp	/usr/lib/misc/sftp-server
  AcceptEnv LANG LC_*

-------  Config END    -------


-------       -------       ---=---       -------       ------- 
Full ssh_config on LHOST:  sudo grep ^[^#] /etc/ssh/ssh_config
-------       -------       ---=---       -------       ------- 

 ForwardX11 yes
 SendEnv LANG LC_*

-------  Config END    -------

#######################################################

Now the same info for RHOST

-------       -------       ---=---       -------       ------- 
Full sshd_config on RHOST: ssh root@RHOST "grep ^[^#] /etc/ssh/sshd_config"
-------       -------       ---=---       -------       ------- 

HostKey /etc/ssh/ssh_host_rsa_key
HostKey /etc/ssh/ssh_host_dsa_key
HostKey /etc/ssh/ssh_host_ed25519_key
AcceptEnv LANG LC_*
ChallengeResponseAuthentication no
IgnoreRhosts yes
HostbasedAuthentication no
KeyRegenerationInterval 3600
LogLevel INFO
LoginGraceTime 120
PermitEmptyPasswords no
PermitRootLogin yes
Port 22
PrintLastLog yes
PrintMotd no
Protocol 2
PubkeyAuthentication yes
RSAAuthentication yes
RhostsRSAAuthentication no
ServerKeyBits 1024
SyslogFacility AUTH
StrictModes yes
Subsystem   sftp        /usr/lib/misc/sftp-server
TCPKeepAlive yes
UsePAM yes
UsePrivilegeSeparation sandbox
X11Forwarding yes

-------  Config END    -------


-------       -------       ---=---       -------       ------- 
Full ssh_config on RHOST: ssh root@RHOST "grep ^[^#] /etc/ssh/ssh_config"
-------       -------       ---=---       -------       ------- 
Host *
   ForwardX11 yes
    SendEnv LANG LC_*
    HashKnownHosts yes

-------  Config END    -------

############################################
############################################

The only thing more I can think to include is the full lengthy output of
ssh -vv -X