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https://issues.apache.org/jira/browse/GUACAMOLE-703?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16744488#comment-16744488
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Nick Couchman commented on GUACAMOLE-703:
-----------------------------------------

{quote}
Question though - If I can SSH fine from the Guac server's CLI, wouldn't that 
use the same libssh library?
{quote}

No, the "ssh" command on the server is OpenSSH, which does not use the libssh2 
library.

> SSH Handshake Failed
> --------------------
>
>                 Key: GUACAMOLE-703
>                 URL: https://issues.apache.org/jira/browse/GUACAMOLE-703
>             Project: Guacamole
>          Issue Type: Bug
>          Components: SSH
>    Affects Versions: 0.9.14, 1.0.0
>            Reporter: Patrick Sullivan
>            Priority: Minor
>
> Update: Built a brand new Guac 1.0.0 install, same issue. Further details 
> below.
> When attempting to use Guacamole 1.0.0 to connect via SSH to an Appliance 
> that has a proprietary shell (non-bash), SSH connects to the server via Guac, 
> however disconnects after password is submitted.
> Event logs on Guac server show 'SSH Handshake Failed', but no other info. 
> Able to connect to the appliance using Putty, Terraterm SSH clients, and able 
> to SSH from Guac server CLI also without issue. 
> Only occurs on SSH servers where the vendor has implemented their own 
> restricted shell, e.g. as many pre-packaged virtual appliances have. 
> Guac Server OS: CentOS Linux release 7.6.1810 (Core)
> SSH Server: Server version: SSH-2.0-OpenSSH_5.3
> Log excerpts below. 
>  
>  GUAC Log:
> {code:none}
> Jan 15 18:53:33 <hostname> guacd[7046]: User 
> "@abf93eb1-fef9-4bb6-908d-bd5316093b0d" joined connection 
> "$92e78549-bd3e-4743-97e6-54925ada845a" (1 users now present)
> Jan 15 18:53:33 <hostname> server: 18:53:33.404 [http-bio-8443-exec-4] INFO  
> o.a.g.tunnel.TunnelRequestService - User "guacadmin" connected to connection 
> "15".
> Jan 15 18:53:38 <hostname> guacd[7046]: SSH handshake failed.
> Jan 15 18:53:38 <hostname> guacd[7046]: User 
> "@abf93eb1-fef9-4bb6-908d-bd5316093b0d" disconnected (0 users remain)
> Jan 15 18:53:38 <hostname> guacd[7046]: Last user of connection 
> "$92e78549-bd3e-4743-97e6-54925ada845a" disconnected
> {code}
>  
>  In the below log except, taken from a working client (PUtty), the Guac 
> server usually disconnects between the {{<—XXXXXXXXX—>}} parts of the 
> sequence straight after the user provides the password, appears to be when 
> the server switches to it's proprietary shell. 
> From a (Working) SSH Client Log to the affected SSH Server/Appliance:
> {code:none}
> Event Log: Server version: SSH-2.0-OpenSSH_5.3
> Event Log: We believe remote version has SSH-2 channel request bug
> Event Log: Using SSH protocol version 2
> Event Log: Doing Diffie-Hellman group exchange
> Event Log: Doing Diffie-Hellman key exchange with hash SHA-256
> Event Log: Host key fingerprint is:
> Event Log: Initialised AES-256 SDCTR client->server encryption
> Event Log: Initialised HMAC-SHA-256 client->server MAC algorithm
> Event Log: Initialised AES-256 SDCTR server->client encryption
> Event Log: Initialised HMAC-SHA-256 server->client MAC algorithm
> Event Log: Sent password
> <---XXXXXXXX--->
> Event Log: Access granted
> Event Log: Opening session as main channel
> Event Log: Opened main channel                                 
> Event Log: Allocated pty (ospeed 38400bps, ispeed 38400bps)                   
>              
> Event Log: Started a shell/command
> Incoming packet #0x9, type 93 / 0x5d (SSH2_MSG_CHANNEL_WINDOW_ADJUST) 
> <---XXXXXXXX--->
> {code}
> Install versions of libssh as requested:
> libssh2.x86_64 1.4.3-12.el7 @base
>  libssh2-devel.x86_64 1.4.3-12.el7 @base
>  openssh.x86_64 7.4p1-16.el7 @anaconda
>  openssh-clients.x86_64 7.4p1-16.el7 @anaconda
>  openssh-server.x86_64 7.4p1-16.el7 @anaconda



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