Hi Mike,
thanks for the confirmation and the submission.

If anyone is interested, one thing I did for now, to address this issue was to allow password-based access from my LAN addresses as described here: http://askubuntu.com/questions/101670/how-can-i-allow-ssh-password-authentication-from-only-certain-ip-addresses (Note that the match block should be at the end of sshd_config file as it affects all statements below it if I understand it correctly)

Use a Match block in /etc/ssh/sshd_config.

PasswordAuthentication no

Match address 192.0.2.0/24
    PasswordAuthentication yes
Best,
Matthias

PS: Is there a comfortable way to reply to individual messages from the digest email that doesn't involve plenty of copy &paste + praying that it will be sorted correctly like just now? Probably no, right?

On 28/8/2013 12:00 PM, x2go-user-request@lists.berlios.de wrote:
Hi Matthias,

On Mo 26 Aug 2013 23:54:55 CEST Matthias Kauer wrote:


Hi,
I am looking for input on how to set up an ssh key-based authentication.

I generated an RSA key pair with puttygen and added it to
~/.ssh/authorized_keys2 => confirmed that I can login with putty.
Now, I specify the same private key in x2goclient (windows). I enter my
password and I am then prompted for the password of the ssh key. I enter
it and the same ssh key password prompt reappears. This seems to be an
infinite loop. When I cancel it, I get a message saying that only
publickey is supported as login method (which corresponds to my
sshd_config settings).

I then tried renaming ~/.ssh/authorized_keys and using a DSA key pair.
putty still works as expected with both of these alternatives.
x2goclient still shows the same problems however. It only lets me login
if I adapt my sshd_config and authenticate via user / password combination.

Is this a known limitation?
What is the best way to achieve high security? Can I limit the x2go
connections to only LAN IPs (without restricting the pure ssh connections)?

I have just forwarded this issue to our bug tracker. I have observed  
similar irregularities that desperately need a fix.

Mike