Embedded putty, putty 0.6x and openssh 6.9p1...Access Denied and other..

[fbolo]

Hi,
We have ASG-2015 patch 7 and noticed some strange effects using embedded putty with openssh 6.9p1, 6.8p1 and a external putty etc etc... I try to explain:

1) Using embedded ASG-2015p7 putty with stored credentials and connecting via ssh to a server with installed new openssh6.9p1 I'm unable to connect to this server as in attached picture putty_embedded_with_ssh6.9p1.jpg

2) Using putty 0.6(2,3,4,5 beta ) with stored credentials and connecting via ssh to a server with installed new openssh6.9p1 I'm able to connect to this server as in attached picture access_denied.jpg BUT the credentials are NOT recognized ( root and all other acccounts ). The password it's OK because if I manually insert it I'm able to logon...

3) Using embedded ASG-2015p7 putty with stored credentials and connecting via ssh to a server with OLD openssh6.Xp1 ( 6,8p1 in my case ) version I'm able to connect to this server as in putty_with_sshd6.8p1 AND the credential are correctly passed...

4) This problems ara with SSH connections and not for example with RDP...

So the putty configuration ( embedded and external ) are the same, and the sshd_config for openssh6.8p1 and openssh 6.9p1 are the same... Where is the problem???

So what is the difference between embedded putty and normal putty version?
I would like to use external putty ( 0.62,3,4,5... ) to connect to linux/unix server with openssh 6.9p1 or major and correctly do the autologon with stored credentials!!!
Can you help me?

Many thanks in advance.
Fabio.

[DevOma]

The difference between "Integrated Putty" and "Standard Putty" is the password transfer - we customized putty so we can handover a decrypted password - standard putty uses password in cleartext as command line parameter...

I don't know why you can't login to new OpenSSH-versions - we have to check this...

[fbolo]

Hi Oliver,

I found the problem... It seems that with embedded putty to connect to newer version of openssh starting from 6.9p1 you need to select as first key exchange algorithm selection this DH group:

Difie-Hellman group 14

as show on attached picture. This is due probably to a security feature of new openssh.

Thanks.

Fabio.