Invalid Client Protocol Banner - Null terminated - WeOnlyDo Discussion board

Invalid Client Protocol Banner - Null terminated (wodSSH / wodSSH.NET)

by AdrianWatkins, Tuesday, June 08, 2021, 13:01 (108 days ago)

I have been using WODSSH for an applicaiton that SSH to many sevrers without issue but now when tryign to connetc to an UBUNTU server the server is giving me:

kex_exchange_identification: banner line contains invalid characters

Looking at the trace in wireshark I can see the banner is terminated 0x00 0x0a whereas according to teh RFC it should be terminated 0x0d 0x0a and it seems to be this that is upsetting the server which then closed the socket.

Anyway I can resolve this - the release notes done suggets this is fixed?

Invalid Client Protocol Banner - Null terminated

by wodSupport, Tuesday, June 08, 2021, 15:09 (107 days ago) @ AdrianWatkins

Hi.

Not sure what is this error about. What banner are you refering to? Initial client exchange? It should not have zeros inside.

What ubuntu version, and what OpenSSH version are you using? Can we try to connect there?

Regards,
jasmine

Invalid Client Protocol Banner - Null terminated

by AdrianWatkins, Tuesday, June 08, 2021, 16:49 (107 days ago) @ wodSupport

hello - im using WODSSH.dll 3.1.2.232.

I make an outbound SSH Connectionn and the intiial protocol exchange is a banner from the server:

Protocol: SSH-2.0-OpenSSH_8.2p1 Ubuntu-4ubuntu0.2\r\n

followed by the client (WODSSH):

Protocol: SSH-1.99-WeOnlyDo 3.1.2.232

however this stream in hex is:
5353482d312e39392d57654f6e6c79446f20332e312e322e323332000a

as you can see this is terminated 0x00 and 0x0a

My code has been in use for ages and Ive been asked to see why its not connecting to Ubuntu but works to Cisco devices for SSH. The 00 is disliked as the RFC says this shouldnt be included.

I have tried changing the Client name with SSH.ClientName but whilst this changes the name, it is still terminated with 00 0a and thus fails.

Note: This is ActiveX

Invalid Client Protocol Banner - Null terminated

by wodSupport, Tuesday, June 08, 2021, 18:05 (107 days ago) @ AdrianWatkins

Hi.

Since there were major changes since your version that deal with initial packet, please try it with the latest version, perhaps problem is already solved.

If it's not and need to be solved - it will be based on latest version anyway, so it's good starting point. If possible to give us access to that computer (after you tested latest version doesn't work correctly) please send us details to technicall support email so we can help you out.

Regards,
Jasmine