x forwarding is not happening with ssh

vasudharao · 03-13-2008, 07:54 AM

I am using one host computer and an embedded board(ARM processor linux)..
Both are in the same network..

ssh is happening properly between two systems..

But I can't open display(e.g.,aterm) between either systems when I did ssh ..
X forwarding is happening between other systems in the network..
But cant do x forwarding w.r.t.embedded board..

Here are some outputs I got..

Code:

(From host to board)

[vasudha@localhost ~]$ ssh -X -vvv root@192.168.1.57
OpenSSH_4.3p2, OpenSSL 0.9.8b 04 May 2006
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Applying options for *
debug2: ssh_connect: needpriv 0
debug1: Connecting to 192.168.1.57 [192.168.1.57] port 22.
debug1: Connection established.
debug3: Not a RSA1 key file /home/vasudha/.ssh/id_rsa.
debug2: key_type_from_name: unknown key type '-----BEGIN'
    .
    .
   
debug2: callback start
debug2: x11_get_proto: /usr/bin/xauth  list unix:10.0 2>/dev/null
Warning: No xauth data; using fake authentication data for X11 forwarding.
debug1: Requesting X11 forwarding with authentication spoofing.
    .
    .
    .
    .
debug2: channel 0: request shell confirm 0
debug2: fd 3 setting TCP_NODELAY
debug2: callback done
debug2: channel 0: open confirm rwindow 0 rmax 32768
debug1: Remote: No xauth program; cannot forward with spoofing.
debug2: channel 0: rcvd adjust 131072
Last login: Thu Jan  1 03:00:38 1970 from 192.168.1.60
[root@INN /root]$aterm 
aterm: can't load font "7x14"
config_geom = 501x316
root_geom = 501x316+4+30, root_size = 640x480

(Here it hangs for ever..)

(From board to host..)
[root@INN board]$ssh -X -vvv vasudha@192.168.1.60
OpenSSH_3.7.1p2, SSH protocols 1.5/2.0, OpenSSL 0.9.7b 10 Apr 2003
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Applying options for *
debug3: RNG is ready, skipping seeding
debug2: ssh_connect: needpriv 0
debug1: Connecting to 192.168.1.60 [192.168.1.60] port 22.
debug1: Connection established.
debug1: identity file /root/.ssh/id_rsa type -1
debug1: identity file /root/.ssh/id_dsa type -1
     .
     .
     .
debug3: tty_make_modes: 92 0
debug3: tty_make_modes: 93 0
debug1: No xauth program.
Warning: No xauth data; using fake authentication data for X11 forwarding.
debug1: Requesting X11 forwarding with authentication spoofing.
debug2: channel 0: request x11-req
debug2: channel 0: request shell
debug2: fd 3 setting TCP_NODELAY
debug2: callback done
debug2: channel 0: open confirm rwindow 0 rmax 32768
debug2: channel 0: rcvd adjust 131072
Last login: Thu Mar 13 15:41:20 2008 from 192.168.1.57
[vasudha@localhost ~]$ xterm
_X11TransSocketINETConnect() can't get address for localhost:6010: Temporary failure in name resolution
xterm Xt error: Can't open display: localhost:10.0
[vasudha@localhost ~]$ 
(it willnot hang here..no display also..)

*In /etc/ssh/sshd_config of both the systems, I did,..

X11Forwarding yes

Can anyone tel me why I am getting these types of warnings..?

Can you tell me the steps to resolve this ??

Thanks in advance..

Agrouf · 03-13-2008, 09:03 AM

try ssh -Y instead of -X

hashbangbinbash · 03-13-2008, 12:06 PM

I have a problem x-forwarding as well, I'm using Gentoo on a remote dedicated server.

first

Quote:

ssh -X -vvv root@my.box.net

and then

Quote:

hashbangbinbash ~ # ddd
Error: Can't open display:

ddd is just a debugging tool, and there were no errors on the -vvv output. I've tried using ssh with -X as well as -Y but with the same error message. Any suggestions?

reddazz · 03-13-2008, 12:50 PM

Does /etc/ssh/sshd_config have the line

Code:

X11Forwarding yes

vasudharao · 03-13-2008, 10:13 PM

Yes..since both of my systems are not supporting x forwarding,I did
X11Forwarding yes in /etc/ssh/sshd_config in both the systems..

When I did ssh with -Y also I am getting same debug message..
"debug1: Remote: No xauth program; cannot forward with spoofing."
What is this mean..??

Can anyone tel me what is xauth program?
I think it is needed in my case..

Thank you..

vasudharao · 03-14-2008, 12:27 AM

I searched in google..its mentioned one place that if you get warning
"No xauth data; using fake authentication data for X11 forwarding"then you should add "XAuthLocation /usr/bin/xauth" to /etc/ssh/ssh_config..I did the same but facing same problem..

Anyone know about this issue..??

Thank you..

vasudharao · 03-14-2008, 12:59 AM

Can you tel me what is ~/.Xauthority file..
It is present in my host system but it is not present in my embedded board..Is this creating problem..??

If needed,How to create ~/.Xauthority file..??

vasudharao · 03-14-2008, 07:37 AM

I removed the warning "debug1: Remote: No xauth program; cannot forward with spoofing."(while doing ssh from host to board)
What I did is,

I added "/usr/X11R6/lib" to /etc/ld.so.conf

I added "XAuthLocation /usr/X11R6/bin/xauth" to /etc/ssh/sshd_config
and restarted sshd..

But still xforwarding is not happening..

when I use aterm in board after doing ssh,I get..

aterm: can't load font "7x14"
config_geom = 501x316
root_geom = 501x316+4+30, root_size = 640x480
(and hangs forever_

If I run other gtk application also it hangs forever without any warnings..

Can you help me in this..??

Thank you..

hashbangbinbash · 03-14-2008, 09:07 AM

Quote:

Originally Posted by reddazz

Does /etc/ssh/sshd_config have the line

Code:

X11Forwarding yes

Yes, yes it does.

Sm1ler · 03-14-2008, 09:24 AM

Are you sure you made the changes to the /etc/ssh/sshd_config and not the ssh_config that has caught me out a number of times - Also as a simple test try ssh -o ForwardX11=yes user@host I use this method for a few things but should work fine for xterm gnome-terminal etc etc infact I have no problems with it for everything! Hope this helps.. Also on another note this even works on most systems with the sshd_conf set to (x11forwarding no) I guess because I am not forwarding the whole xserver.

hashbangbinbash · 03-14-2008, 11:56 AM

For myself, it still comes back with: can't open display.

vasudharao · 03-18-2008, 12:26 AM

Hey..X forwarding is happening in one direction.. i.e.,I can see gedit window of my system on my board's screen..what I did is..I have added
"nameserver xxx.xxx.xxx.xxx" to /etc/resolve.conf file..

But from host to board x forwarding is not happening..i.e., when I did aterm (after ssh with -X from host to board)in board,window displayed on the board,but in host no display..

/etc/resolve.conf files are similar in both the systems..

what may be other issue..??

Agrouf · 03-18-2008, 01:32 AM

vasudharao, I didn't get it. What are you calling the board?

how to use xauth :
xauth gives you the authorithy to open a window on the X server is authentification is activated on the X server. Normally, authorithy keys are handled automatically by ssh when you do -X. -Y is for when authorithy is not activated on the X server (the X server is the ssh client).
Th handle xauth manually, you can do a "xauth -extract filename $DISPLAY" to extract the authorization you have with your user to open a window to a file named filename. Then, you have to scp this file to where you connect to with ssh. You can then merge this authorisation with the sshed user's ~/.Xauthority file with that command : xauth merge filename.
If you handle the authority yourself, you don't need the -X anymore. You can simply forward the X port like this :
ssh -R 60xx:localhost:60xx foreignhost
then, do export DISPLAY=localhost:xx, so you use the right display.
(of course, replace xx with the DISPLAY number you want to use).

vasudharao · 03-18-2008, 11:02 PM

* I am developing applications for ARM processor..(as mentioned in the earlier post)..my ARM processor is having linux as its OS..I am calling this as my board(embedded board)..

* Right now I am able to do..
> when I do ssh -X from board to host,and then when I run gedit, I can see the window on my board's screen..
> but reverse is not possible..i.e.,when I do ssh -X from host to board, windows of board's applications I cannt see on host's screen..application hangs for ever without warning....

I think I answered your questions..

I did "ssh -o ForwardX11=yes user@host" also but still no change..

Can you help me..?

Thank you..

jschiwal · 03-18-2008, 11:21 PM

When connecting from the board to your computer, do you have the X server running on the board? Was X properly installed?
You seem to be having problems like not being able to find xauth, libraries & resources.