Hi Nick,

Can you please help with one query related to upgrading libssh2 library in
guacamole:


if you're having trouble connecting with one of the above algorithms, then
you should upgrade libssh2 to the latest release and try, again.
--> We are using official docker image "guacamole/guacd:1.0.0". How can we
upgrade libssh2 to the latest version(v1.9.0) ?
Do we need to follow this link
<https://guacamole.apache.org/doc/gug/installing-guacamole.html> to build
guacamole from source code with upgraded libssh2.

Regards,
Abhijeet Jha

On Wed, Jul 15, 2020 at 4:57 PM Abhijeet Jha <[email protected]>
wrote:

> Hi Nick,
>
> If you're having trouble connecting to any SSH connection, you need to
> make sure that guacd was built with SSH support.
> --> The issue is with only certain Cisco devices for couple of customers,
> SSH connections are working for other customers. So our guacamole does have
> SSH support.
>
>
> if you're having trouble connecting with one of the above algorithms, then
> you should upgrade libssh2 to the latest release and try, again.
> --> We are using official docker image "guacamole/guacd:1.0.0". How can
> we upgrade libssh2 to the latest version(v1.9.0) ?
> Do we need to follow this link
> <https://guacamole.apache.org/doc/gug/installing-guacamole.html> to build
> guacamole from source code with upgraded libssh2.
>
> Regards,
> Abhijeet Jha
>
>
> On Tue, Jul 14, 2020 at 5:38 PM Nick Couchman <[email protected]> wrote:
>
>> On Tue, Jul 14, 2020 at 6:43 AM Abhijeet Jha <
>> [email protected]> wrote:
>>
>>> Hi Nick,
>>>
>>> Sorry for providing incorrect information, the customer device is
>>> configured to use the following Kex algorithm and not "KexAlgorithms
>>> diffie-hellman-group16-sha512".
>>>
>>>    - diffie-hellman-group-exchange-sha1
>>>    - diffie-hellman-group14-sha1
>>>    - diffie-hellman-group1-sha1
>>>
>>>    Ciphers*: *aes256-cbc
>>>    MAC: hmac-sha1
>>>
>>>    I have sorted out attached debug logs from the production server and
>>>    will be easy for you to look at.
>>>
>>>    We performed some testing with a customer device by using ssh client
>>>    JSCH.4.0.0 which worked fine but the ssh connection did not work with
>>>    guacamole 1.0.0.
>>>
>>>
>> The support for SSH and algorithms has nothing to do with Java or any
>> ability for a Java-based SSH client to connect.  The functionality is
>> provided by guacd, which leverages the libssh2 library for SSH support.
>> Thus, the key algorithms must be supported by libssh2.  If you look at
>> their web page (libssh2.org), you'll see the list of key exchange
>> algorithms supported by the current version of the library:
>>
>> * Key Exchange Methods: diffie-hellman-group1-sha1,
>> diffie-hellman-group14-sha1, diffie-hellman-group-exchange-sha1,
>> diffie-hellman-group-exchange-sha256
>>
>> Please note that this is what is supported in the *current* version - if
>> you're having trouble connecting with one of the above algorithms, then you
>> should upgrade libssh2 to the latest release and try, again.  Note that
>> this may well be the case for the Ciphers and MAC, as well - it's possible
>> that one or more of those has been added in a recent version of libssh2,
>> and if you're using something older you may not have that support.
>>
>> If you're having trouble connecting to any SSH connection, you need to
>> make sure that guacd was built with SSH support.
>>
>>>
>>>    -
>>>    We upgraded  guacamole from 0.9.3 to 1.0.0 in May 2019 and customer
>>>    reported that ssh to their Cisco devices stopped working which was
>>>    working till the time they reported the problem to us.
>>>
>>>
>>> I'm not familiar with version history going back that far, but it's
>> quite possible that 0.9.3 was prior to the move from libssh to libssh2, and
>> that libssh had supported those algorithms and libssh2 did not.  It's also
>> possible that the build does not include SSH support because one or more of
>> the dependencies is missing when guacd was built.
>>
>> So, start by verifying that guacd does include SSH support (you can
>> connect to at least one SSH server successfully), then move on to
>> attempting to upgrade libssh2 to the latest, and rebuild guacd against that.
>>
>> -Nick
>>
>

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