SSH Debugging – Fix X11 Connection Rejected Due to Wrong Authentication

debugloggingsshx11-forwarding

I have a problem with X forwarding through SSH. I've battled for ages, but no-one can seem to help.

I'm now taking a different tact. I would like to know how I would debug the errors?

What logs should I look in, what extra flags should I set (-v etc) and what should I look for?

Further Edit:

If I log into Putty into the server and try to xeyes, I get:

PuTTY X11 proxy: wrong authorisation protocol attemptedError: Can't open display: localhost:10.0

If I xauth generate $DISPLAY I get:

PuTTY X11 proxy: wrong authorisation protocol attemptedxauth: (argv):1: unable to open display "localhost:10.0".

Best Answer

My solution step by step:

1) login with option -X remote host login root

$ ssh -X root@192.168.1.39

2) check if existing .Xauthority file

[root@localhost ~]# ls -al
[root@localhost ~]# vim .Xauthority

3) copy .Xauthority file to directory the other user

[root@localhost ~]# cp .Xauthority /home/oracle/
cp: overwrite `/home/oracle/.Xauthority'? y

4) set permissions for this file

[root@localhost ~]# chown oracle:oinstall .Xauthority
[root@localhost ~]# chmod 0600 .Xauthority

5) login oracle user

[root@localhost ~]# su - oracle

6) display setting in localhost:10.0

[oracle@localhost ~]$ echo $DISPLAY
localhost:10.0
[oracle@localhost ~]$ ls -al

7) lists xauth cookies existing

[oracle@localhost ~]$ xauth list
localhost.localdomain/unix:11  MIT-MAGIC-COOKIE-1  310f1b02c1080e73059391c193a1881b
localhost.localdomain/unix:10  MIT-MAGIC-COOKIE-1  41843db100830a2aa352641ac47bb759

8) adding

[oracle@localhost ~]$ xauth add localhost.localdomain/unix:10  MIT-MAGIC-COOKIE-1  41843db100830a2aa352641ac47bb75

9) test

[oracle@localhost ~]$ xclock

Hope they serve! @wcaraza