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https://issues.apache.org/jira/browse/SSHD-968?focusedWorklogId=394022&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-394022
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ASF GitHub Bot logged work on SSHD-968:
---------------------------------------

                Author: ASF GitHub Bot
            Created on: 27/Feb/20 08:15
            Start Date: 27/Feb/20 08:15
    Worklog Time Spent: 10m 
      Work Description: lgoldstein commented on issue #112: SSHD-968
URL: https://github.com/apache/mina-sshd/pull/112#issuecomment-591840036
 
 
   The suggested fix seems to involve too many methods changes - not mention 
the fact that the extra argument is very specific to this issue. What if future 
fixes require more argument ? However, your fix has given me an idea I would 
like to explore that may provide (IMO) a better solution. Be patient for 1-2 
days and I might have something.
 
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Issue Time Tracking
-------------------

    Worklog Id:     (was: 394022)
    Time Spent: 20m  (was: 10m)

> SshClient times out during keep-alive, when SSH_MSG_GLOBAL_REQUEST is replied 
> with SSH_MSG_UNSUPPORTED
> ------------------------------------------------------------------------------------------------------
>
>                 Key: SSHD-968
>                 URL: https://issues.apache.org/jira/browse/SSHD-968
>             Project: MINA SSHD
>          Issue Type: Improvement
>    Affects Versions: 2.3.0
>         Environment: Windows 10
>            Reporter: Patrik Ek
>            Assignee: Guillaume Nodet
>            Priority: Major
>          Time Spent: 20m
>  Remaining Estimate: 0h
>
> In case SSH_MSG_GLOBAL_REQUEST is not supported by the remote SSH server, the 
> keep-alive heartbeat times out. The reason for this is SSH_MSG_UNIMPLEMENTED 
> is only logged in
> {color:#172b4d}org.apache.sshd.common.session.helpers{color}.AbstractSession
> The method identifying the SSH_MSG_UNIMPLEMENTED is called 
> AbstractSession.doHandleMessage()
> The consequense is that no reply is received and the heartbeat times out 
> instead of calling AbstractSession.requestFailure(). Which in turn leads to 
> the session terminates.
> According to RFC 4253 sect. 11.4 
> ({color:#004000}https://tools.ietf.org/html/rfc4253#section-11.4{color}) the 
> SSH_MSG_UNIMPLEMENTED is meant to be ignored, but this makes little sense for 
> a heartbeat, as even SSH_MSG_UNIMPLEMENTED is good enough to count as a reply 
> for this. This is for example the case in OpenSSH, where 
> SSH_MSG_UNIMPLEMENTED replies for heartbeat, does not lead to a termination 
> of the SSH session.
> There is a workaround released in 2.1.1, to useĀ 
> ReservedSessionMessagesHandler for handling replies, but this does not allow 
> access to the method AbstractSession.requestFailure() (without using 
> reflection so to say). Further, the heartbeat is ongoing in the background, 
> so there is no good solution to this problem from outside of the framework.
> https://issues.apache.org/jira/browse/SSHD-887?jql=project%20%3D%20SSHD%20AND%20fixVersion%20%3D%202.1.1
> Would this be possible to fix? The reason I write it here is because the bug 
> seems to existing up to some version of libssh, even for the SSHv2 protocol, 
> so just writing a bug report on the particular server will not solve the 
> problems for already existing implementations using libssh.
> The following config is used,
> SshClient client = 
> SshClient.setUpDefaultClient(){color:#cc7832};{color}{color:#808080}
> {color} {color:#172b4d}PropertyResolverUtils.updateProperty(client, 
> ClientFactoryManager.HEARTBEAT_INTERVAL, 15000);
>  
> PropertyResolverUtils.updateProperty(client,ClientFactoryManager.HEARTBEAT_REPLY_WAIT,
>  30000);
>  
> PropertyResolverUtils.updateProperty(client,ClientFactoryManager.HEARTBEAT_REQUEST,
>  "keepal...@openssh.com");{color}
> {color:#cc7832}{color:#172b4d}BR{color}
> {color:#172b4d}Patrik{color}
> {color}



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