X11Forward and xauth problems

[Andrew DeFaria]

On 3/23/2015 2:06 PM, Jon TURNEY wrote:
> On 23/03/2015 20:48, Andrew DeFaria wrote:
>> Normally I just turn on -X (or put X11Forward yes in ~/.ssh/config) but
>> that usually results in a noticeable delay in logging in and the
>> following error:
>>
>> Warning: untrusted X11 forwarding setup failed: xauth key data not
>> generated
>> Warning: No xauth data; using fake authentication data for X11
>> forwarding.
>
> Firstly, if you don't want these warnings, use ssh -Y.
>
> (By using ssh -X, you are asking for something which the X server can't
> give you, hence the warnings.  See
> http://x.cygwin.com/docs/faq/cygwin-x-faq.html#q-trusted-untrusted-x11-forwarding
> for more details)

Yeah but -Y gives me the same thing:

Adefaria-lt:ssh -Y cm-app-ldev01
Warning: No xauth data; using fake authentication data for X11 forwarding.
/usr/bin/xauth:  unable to link authority file 
/home/adefaria/.Xauthority, use /home/adefaria/.Xauthority-n
Cm-app-ldev01:

>
>> /usr/bin/xauth:  unable to link authority file
>> /home/adefaria/.Xauthority, use /home/adefaria/.Xauthority-n
>> Cm-app-ldev01:
>>
>> I've asked about this in the past and I think the answer was that the
>> message was correct but you shouldn't worry about it. If it didn't slow
>
> I'm sorry, I only have a vague memory of this discussion.
>
>> me down I probably would just ignore it. But it slows me down. So I ssh
>> instead without X11Forward turned on then, when I need to run an X
>> client, I do export DISPLAY=adefaria-lt:0 and make sure that I did an
>> xhost + there at least once. But now that's broken!
>>
>> Adefaria-lt:xhost +
>> access control disabled, clients can connect from any host
>> Adefaria-lt:ssh cm-app-ldev01
>> Cm-app-ldev01:export DISPLAY=adefaria-lt:0
>> Cm-app-ldev01:xclock
>> Error: Can't open display: adefaria-lt:0
>> Cm-app-ldev01:
>
> If you want this to work, you will now (since X server 1.17) need to
> start the server with the option '-listen tcp'.

Restarted Xwin with -multimonitor and -listen tcp. Now I get:

Adefaria-lt:ssh -Y cm-app-ldev01
Warning: No xauth data; using fake authentication data for X11 forwarding.
/usr/bin/xauth:  unable to link authority file 
/home/adefaria/.Xauthority, use /home/adefaria/.Xauthority-n
Cm-app-ldev01:echo $DISPLAY
localhost:10.0
Cm-app-ldev01:xclock
X11 connection rejected because of wrong authentication.
Error: Can't open display: localhost:10.0
Cm-app-ldev01:


>
> [1] https://cygwin.com/ml/cygwin-xfree-announce/2015-02/msg00026.html
> [2]
> http://x.cygwin.com/docs/ug/using-remote-apps.html#using-remote-apps-telnet
> [3]
> http://x.cygwin.com/docs/faq/cygwin-x-faq.html#q-remote-clients-cant-connect
>
> [4] https://cygwin.com/ml/cygwin-xfree/2015-02/msg00051.html
>


-- 
Andrew DeFaria
http://defaria.com


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